diff options
author | ru <ru@FreeBSD.org> | 2006-09-21 07:45:37 +0000 |
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committer | ru <ru@FreeBSD.org> | 2006-09-21 07:45:37 +0000 |
commit | c13f72f1a0dcbb8ed60899ee073d4ead6e9ce50e (patch) | |
tree | f21e1d6114aaadaad64190e8e5e6323ab9da07ca /contrib | |
parent | 8e2099e1ea252237fc81e7cd907fa7a0dcf17ad8 (diff) | |
parent | 0981bee8222a23e48705eabd5aed24e4fb17d049 (diff) | |
download | FreeBSD-src-c13f72f1a0dcbb8ed60899ee073d4ead6e9ce50e.zip FreeBSD-src-c13f72f1a0dcbb8ed60899ee073d4ead6e9ce50e.tar.gz |
This commit was generated by cvs2svn to compensate for changes in r162509,
which included commits to RCS files with non-trunk default branches.
Diffstat (limited to 'contrib')
-rw-r--r-- | contrib/gcc/doc/cpp.1 | 491 | ||||
-rw-r--r-- | contrib/gcc/doc/gcc.1 | 8582 | ||||
-rw-r--r-- | contrib/gcc/doc/gcov.1 | 422 |
3 files changed, 5506 insertions, 3989 deletions
diff --git a/contrib/gcc/doc/cpp.1 b/contrib/gcc/doc/cpp.1 index 8b74123..17fdd01 100644 --- a/contrib/gcc/doc/cpp.1 +++ b/contrib/gcc/doc/cpp.1 @@ -1,8 +1,7 @@ -.\" Automatically generated by Pod::Man version 1.15 -.\" Wed Feb 5 03:13:55 2003 +.\" Automatically generated by Pod::Man v1.37, Pod::Parser v1.14 .\" .\" Standard preamble: -.\" ====================================================================== +.\" ======================================================================== .de Sh \" Subsection heading .br .if t .Sp @@ -15,12 +14,6 @@ .if t .sp .5v .if n .sp .. -.de Ip \" List item -.br -.ie \\n(.$>=3 .ne \\$3 -.el .ne 3 -.IP "\\$1" \\$2 -.. .de Vb \" Begin verbatim text .ft CW .nf @@ -28,15 +21,14 @@ .. .de Ve \" End verbatim text .ft R - .fi .. .\" Set up some character translations and predefined strings. \*(-- will .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left .\" double quote, and \*(R" will give a right double quote. | will give a -.\" real vertical bar. \*(C+ will give a nicer C++. Capital omega is used -.\" to do unbreakable dashes and therefore won't be available. \*(C` and -.\" \*(C' expand to `' in nroff, nothing in troff, for use with C<> +.\" real vertical bar. \*(C+ will give a nicer C++. Capital omega is used to +.\" do unbreakable dashes and therefore won't be available. \*(C` and \*(C' +.\" expand to `' in nroff, nothing in troff, for use with C<>. .tr \(*W-|\(bv\*(Tr .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' .ie n \{\ @@ -56,10 +48,10 @@ . ds R" '' 'br\} .\" -.\" If the F register is turned on, we'll generate index entries on stderr -.\" for titles (.TH), headers (.SH), subsections (.Sh), items (.Ip), and -.\" index entries marked with X<> in POD. Of course, you'll have to process -.\" the output yourself in some meaningful fashion. +.\" If the F register is turned on, we'll generate index entries on stderr for +.\" titles (.TH), headers (.SH), subsections (.Sh), items (.Ip), and index +.\" entries marked with X<> in POD. Of course, you'll have to process the +.\" output yourself in some meaningful fashion. .if \nF \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" @@ -68,14 +60,13 @@ . rr F .\} .\" -.\" For nroff, turn off justification. Always turn off hyphenation; it -.\" makes way too many mistakes in technical documents. +.\" For nroff, turn off justification. Always turn off hyphenation; it makes +.\" way too many mistakes in technical documents. .hy 0 .if n .na .\" .\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2). .\" Fear. Run. Save yourself. No user-serviceable parts. -.bd B 3 . \" fudge factors for nroff and troff .if n \{\ . ds #H 0 @@ -135,11 +126,10 @@ . ds Ae AE .\} .rm #[ #] #H #V #F C -.\" ====================================================================== +.\" ======================================================================== .\" .IX Title "CPP 1" -.TH CPP 1 "gcc-3.2.2" "2003-02-05" "GNU" -.UC +.TH CPP 1 "2006-03-06" "gcc-3.4.6" "GNU" .SH "NAME" cpp \- The C Preprocessor .SH "SYNOPSIS" @@ -147,7 +137,9 @@ cpp \- The C Preprocessor cpp [\fB\-D\fR\fImacro\fR[=\fIdefn\fR]...] [\fB\-U\fR\fImacro\fR] [\fB\-I\fR\fIdir\fR...] [\fB\-W\fR\fIwarn\fR...] [\fB\-M\fR|\fB\-MM\fR] [\fB\-MG\fR] [\fB\-MF\fR \fIfilename\fR] - [\fB\-MP\fR] [\fB\-MQ\fR \fItarget\fR...] [\fB\-MT\fR \fItarget\fR...] + [\fB\-MP\fR] [\fB\-MQ\fR \fItarget\fR...] + [\fB\-MT\fR \fItarget\fR...] + [\fB\-P\fR] [\fB\-fno\-working\-directory\fR] [\fB\-x\fR \fIlanguage\fR] [\fB\-std=\fR\fIstandard\fR] \fIinfile\fR \fIoutfile\fR .PP @@ -166,12 +158,12 @@ text processor. It will choke on input which does not obey C's lexical rules. For example, apostrophes will be interpreted as the beginning of character constants, and cause errors. Also, you cannot rely on it preserving characteristics of the input which are not significant to -C-family languages. If a Makefile is preprocessed, all the hard tabs +C\-family languages. If a Makefile is preprocessed, all the hard tabs will be removed, and the Makefile will not work. .PP Having said that, you can often get away with using cpp on things which are not C. Other Algol-ish programming languages are often safe -(Pascal, Ada, etc.) So is assembly, with caution. \fB\-traditional\fR +(Pascal, Ada, etc.) So is assembly, with caution. \fB\-traditional\-cpp\fR mode preserves more white space, and is otherwise more permissive. Many of the problems can be avoided by writing C or \*(C+ style comments instead of native language comments, and keeping macros simple. @@ -191,6 +183,16 @@ of a program which does not expect them. To get strict \s-1ISO\s0 Standard C, you should use the \fB\-std=c89\fR or \fB\-std=c99\fR options, depending on which version of the standard you want. To get all the mandatory diagnostics, you must also use \fB\-pedantic\fR. +.PP +This manual describes the behavior of the \s-1ISO\s0 preprocessor. To +minimize gratuitous differences, where the \s-1ISO\s0 preprocessor's +behavior does not conflict with traditional semantics, the +traditional preprocessor should behave the same way. The various +differences that do exist are detailed in the section \fBTraditional +Mode\fR. +.PP +For clarity, unless noted otherwise, references to \fB\s-1CPP\s0\fR in this +manual refer to \s-1GNU\s0 \s-1CPP\s0. .SH "OPTIONS" .IX Header "OPTIONS" The C preprocessor expects two file names as arguments, \fIinfile\fR and @@ -198,10 +200,10 @@ The C preprocessor expects two file names as arguments, \fIinfile\fR and other files it specifies with \fB#include\fR. All the output generated by the combined input files is written in \fIoutfile\fR. .PP -Either \fIinfile\fR or \fIoutfile\fR may be \fB-\fR, which as +Either \fIinfile\fR or \fIoutfile\fR may be \fB\-\fR, which as \&\fIinfile\fR means to read from standard input and as \fIoutfile\fR means to write to standard output. Also, if either file is omitted, it -means the same as if \fB-\fR had been specified for that file. +means the same as if \fB\-\fR had been specified for that file. .PP Unless otherwise noted, or the option ends in \fB=\fR, all options which take an argument may have that argument appear either immediately @@ -211,16 +213,20 @@ after the option, or with a space between option and argument: Many options have multi-letter names; therefore multiple single-letter options may \fInot\fR be grouped: \fB\-dM\fR is very different from \&\fB\-d\ \-M\fR. -.Ip "\fB\-D\fR \fIname\fR" 4 +.IP "\fB\-D\fR \fIname\fR" 4 .IX Item "-D name" -Predefine \fIname\fR as a macro, with definition \f(CW\*(C`1\*(C'\fR. -.Ip "\fB\-D\fR \fIname\fR\fB=\fR\fIdefinition\fR" 4 +Predefine \fIname\fR as a macro, with definition \f(CW1\fR. +.IP "\fB\-D\fR \fIname\fR\fB=\fR\fIdefinition\fR" 4 .IX Item "-D name=definition" Predefine \fIname\fR as a macro, with definition \fIdefinition\fR. -There are no restrictions on the contents of \fIdefinition\fR, but if -you are invoking the preprocessor from a shell or shell-like program you -may need to use the shell's quoting syntax to protect characters such as -spaces that have a meaning in the shell syntax. +The contents of \fIdefinition\fR are tokenized and processed as if +they appeared during translation phase three in a \fB#define\fR +directive. In particular, the definition will be truncated by +embedded newline characters. +.Sp +If you are invoking the preprocessor from a shell or shell-like +program you may need to use the shell's quoting syntax to protect +characters such as spaces that have a meaning in the shell syntax. .Sp If you wish to define a function-like macro on the command line, write its argument list with surrounding parentheses before the equals sign @@ -232,90 +238,132 @@ to quote the option. With \fBsh\fR and \fBcsh\fR, are given on the command line. All \fB\-imacros\fR \fIfile\fR and \&\fB\-include\fR \fIfile\fR options are processed after all \&\fB\-D\fR and \fB\-U\fR options. -.Ip "\fB\-U\fR \fIname\fR" 4 +.IP "\fB\-U\fR \fIname\fR" 4 .IX Item "-U name" Cancel any previous definition of \fIname\fR, either built in or provided with a \fB\-D\fR option. -.Ip "\fB\-undef\fR" 4 +.IP "\fB\-undef\fR" 4 .IX Item "-undef" -Do not predefine any system-specific macros. The common predefined -macros remain defined. -.Ip "\fB\-I\fR \fIdir\fR" 4 +Do not predefine any system-specific or GCC-specific macros. The +standard predefined macros remain defined. +.IP "\fB\-I\fR \fIdir\fR" 4 .IX Item "-I dir" Add the directory \fIdir\fR to the list of directories to be searched for header files. .Sp Directories named by \fB\-I\fR are searched before the standard -system include directories. -.Sp -It is dangerous to specify a standard system include directory in an -\&\fB\-I\fR option. This defeats the special treatment of system -headers -\&. It can also defeat the repairs to buggy system headers which \s-1GCC\s0 -makes when it is installed. -.Ip "\fB\-o\fR \fIfile\fR" 4 +system include directories. If the directory \fIdir\fR is a standard +system include directory, the option is ignored to ensure that the +default search order for system directories and the special treatment +of system headers are not defeated +\&. +.IP "\fB\-o\fR \fIfile\fR" 4 .IX Item "-o file" Write output to \fIfile\fR. This is the same as specifying \fIfile\fR as the second non-option argument to \fBcpp\fR. \fBgcc\fR has a different interpretation of a second non-option argument, so you must use \fB\-o\fR to specify the output file. -.Ip "\fB\-Wall\fR" 4 +.IP "\fB\-Wall\fR" 4 .IX Item "-Wall" -Turns on all optional warnings which are desirable for normal code. At -present this is \fB\-Wcomment\fR and \fB\-Wtrigraphs\fR. Note that -many of the preprocessor's warnings are on by default and have no -options to control them. -.Ip "\fB\-Wcomment\fR" 4 +Turns on all optional warnings which are desirable for normal code. +At present this is \fB\-Wcomment\fR, \fB\-Wtrigraphs\fR, +\&\fB\-Wmultichar\fR and a warning about integer promotion causing a +change of sign in \f(CW\*(C`#if\*(C'\fR expressions. Note that many of the +preprocessor's warnings are on by default and have no options to +control them. +.IP "\fB\-Wcomment\fR" 4 .IX Item "-Wcomment" .PD 0 -.Ip "\fB\-Wcomments\fR" 4 +.IP "\fB\-Wcomments\fR" 4 .IX Item "-Wcomments" .PD Warn whenever a comment-start sequence \fB/*\fR appears in a \fB/*\fR comment, or whenever a backslash-newline appears in a \fB//\fR comment. (Both forms have the same effect.) -.Ip "\fB\-Wtrigraphs\fR" 4 +.IP "\fB\-Wtrigraphs\fR" 4 .IX Item "-Wtrigraphs" -Warn if any trigraphs are encountered. This option used to take effect -only if \fB\-trigraphs\fR was also specified, but now works -independently. Warnings are not given for trigraphs within comments, as -they do not affect the meaning of the program. -.Ip "\fB\-Wtraditional\fR" 4 +@anchor{Wtrigraphs} +Most trigraphs in comments cannot affect the meaning of the program. +However, a trigraph that would form an escaped newline (\fB??/\fR at +the end of a line) can, by changing where the comment begins or ends. +Therefore, only trigraphs that would form escaped newlines produce +warnings inside a comment. +.Sp +This option is implied by \fB\-Wall\fR. If \fB\-Wall\fR is not +given, this option is still enabled unless trigraphs are enabled. To +get trigraph conversion without warnings, but get the other +\&\fB\-Wall\fR warnings, use \fB\-trigraphs \-Wall \-Wno\-trigraphs\fR. +.IP "\fB\-Wtraditional\fR" 4 .IX Item "-Wtraditional" Warn about certain constructs that behave differently in traditional and \&\s-1ISO\s0 C. Also warn about \s-1ISO\s0 C constructs that have no traditional C equivalent, and problematic constructs which should be avoided. -.Ip "\fB\-Wimport\fR" 4 +.IP "\fB\-Wimport\fR" 4 .IX Item "-Wimport" Warn the first time \fB#import\fR is used. -.Ip "\fB\-Wundef\fR" 4 +.IP "\fB\-Wundef\fR" 4 .IX Item "-Wundef" Warn whenever an identifier which is not a macro is encountered in an \&\fB#if\fR directive, outside of \fBdefined\fR. Such identifiers are replaced with zero. -.Ip "\fB\-Werror\fR" 4 +.IP "\fB\-Wunused\-macros\fR" 4 +.IX Item "-Wunused-macros" +Warn about macros defined in the main file that are unused. A macro +is \fIused\fR if it is expanded or tested for existence at least once. +The preprocessor will also warn if the macro has not been used at the +time it is redefined or undefined. +.Sp +Built-in macros, macros defined on the command line, and macros +defined in include files are not warned about. +.Sp +\&\fBNote:\fR If a macro is actually used, but only used in skipped +conditional blocks, then \s-1CPP\s0 will report it as unused. To avoid the +warning in such a case, you might improve the scope of the macro's +definition by, for example, moving it into the first skipped block. +Alternatively, you could provide a dummy use with something like: +.Sp +.Vb 2 +\& #if defined the_macro_causing_the_warning +\& #endif +.Ve +.IP "\fB\-Wendif\-labels\fR" 4 +.IX Item "-Wendif-labels" +Warn whenever an \fB#else\fR or an \fB#endif\fR are followed by text. +This usually happens in code of the form +.Sp +.Vb 5 +\& #if FOO +\& ... +\& #else FOO +\& ... +\& #endif FOO +.Ve +.Sp +The second and third \f(CW\*(C`FOO\*(C'\fR should be in comments, but often are not +in older programs. This warning is on by default. +.IP "\fB\-Werror\fR" 4 .IX Item "-Werror" Make all warnings into hard errors. Source code which triggers warnings will be rejected. -.Ip "\fB\-Wsystem-headers\fR" 4 +.IP "\fB\-Wsystem\-headers\fR" 4 .IX Item "-Wsystem-headers" Issue warnings for code in system headers. These are normally unhelpful in finding bugs in your own code, therefore suppressed. If you are responsible for the system library, you may want to see them. -.Ip "\fB\-w\fR" 4 +.IP "\fB\-w\fR" 4 .IX Item "-w" Suppress all warnings, including those which \s-1GNU\s0 \s-1CPP\s0 issues by default. -.Ip "\fB\-pedantic\fR" 4 +.IP "\fB\-pedantic\fR" 4 .IX Item "-pedantic" Issue all the mandatory diagnostics listed in the C standard. Some of them are left out by default, since they trigger frequently on harmless code. -.Ip "\fB\-pedantic-errors\fR" 4 +.IP "\fB\-pedantic\-errors\fR" 4 .IX Item "-pedantic-errors" Issue all the mandatory diagnostics, and make all mandatory diagnostics into errors. This includes mandatory diagnostics that \s-1GCC\s0 issues without \fB\-pedantic\fR but treats as warnings. -.Ip "\fB\-M\fR" 4 +.IP "\fB\-M\fR" 4 .IX Item "-M" Instead of outputting the result of preprocessing, output a rule suitable for \fBmake\fR describing the dependencies of the main @@ -337,8 +385,9 @@ rules you should explicitly specify the dependency output file with \&\fB\s-1DEPENDENCIES_OUTPUT\s0\fR. Debug output will still be sent to the regular output stream as normal. .Sp -Passing \fB\-M\fR to the driver implies \fB\-E\fR. -.Ip "\fB\-MM\fR" 4 +Passing \fB\-M\fR to the driver implies \fB\-E\fR, and suppresses +warnings with an implicit \fB\-w\fR. +.IP "\fB\-MM\fR" 4 .IX Item "-MM" Like \fB\-M\fR but do not mention header files that are found in system header directories, nor header files that are included, @@ -348,9 +397,10 @@ This implies that the choice of angle brackets or double quotes in an \&\fB#include\fR directive does not in itself determine whether that header will appear in \fB\-MM\fR dependency output. This is a slight change in semantics from \s-1GCC\s0 versions 3.0 and earlier. -.Ip "\fB\-MF\fR \fIfile\fR" 4 +.Sp +@anchor{dashMF} +.IP "\fB\-MF\fR \fIfile\fR" 4 .IX Item "-MF file" -@anchor{\-MF} When used with \fB\-M\fR or \fB\-MM\fR, specifies a file to write the dependencies to. If no \fB\-MF\fR switch is given the preprocessor sends the rules to the same place it would have sent @@ -358,15 +408,18 @@ preprocessed output. .Sp When used with the driver options \fB\-MD\fR or \fB\-MMD\fR, \&\fB\-MF\fR overrides the default dependency output file. -.Ip "\fB\-MG\fR" 4 +.IP "\fB\-MG\fR" 4 .IX Item "-MG" -When used with \fB\-M\fR or \fB\-MM\fR, \fB\-MG\fR says to treat missing -header files as generated files and assume they live in the same -directory as the source file. It suppresses preprocessed output, as a -missing header file is ordinarily an error. +In conjunction with an option such as \fB\-M\fR requesting +dependency generation, \fB\-MG\fR assumes missing header files are +generated files and adds them to the dependency list without raising +an error. The dependency filename is taken directly from the +\&\f(CW\*(C`#include\*(C'\fR directive without prepending any path. \fB\-MG\fR +also suppresses preprocessed output, as a missing header file renders +this useless. .Sp This feature is used in automatic updating of makefiles. -.Ip "\fB\-MP\fR" 4 +.IP "\fB\-MP\fR" 4 .IX Item "-MP" This option instructs \s-1CPP\s0 to add a phony target for each dependency other than the main file, causing each to depend on nothing. These @@ -378,10 +431,11 @@ This is typical output: .Vb 1 \& test.o: test.c test.h .Ve +.Sp .Vb 1 \& test.h: .Ve -.Ip "\fB\-MT\fR \fItarget\fR" 4 +.IP "\fB\-MT\fR \fItarget\fR" 4 .IX Item "-MT target" Change the target of the rule emitted by dependency generation. By default \s-1CPP\s0 takes the name of the main input file, including any path, @@ -397,7 +451,7 @@ For example, \fB\-MT\ '$(objpfx)foo.o'\fR might give .Vb 1 \& $(objpfx)foo.o: foo.c .Ve -.Ip "\fB\-MQ\fR \fItarget\fR" 4 +.IP "\fB\-MQ\fR \fItarget\fR" 4 .IX Item "-MQ target" Same as \fB\-MT\fR, but it quotes any characters which are special to Make. \fB\-MQ\ '$(objpfx)foo.o'\fR gives @@ -405,9 +459,10 @@ Make. \fB\-MQ\ '$(objpfx)foo.o'\fR gives .Vb 1 \& $$(objpfx)foo.o: foo.c .Ve +.Sp The default target is automatically quoted, as if it were given with \&\fB\-MQ\fR. -.Ip "\fB\-MD\fR" 4 +.IP "\fB\-MD\fR" 4 .IX Item "-MD" \&\fB\-MD\fR is equivalent to \fB\-M \-MF\fR \fIfile\fR, except that \&\fB\-E\fR is not implied. The driver determines \fIfile\fR based on @@ -417,26 +472,26 @@ basename of the input file and applies a \fI.d\fR suffix. .Sp If \fB\-MD\fR is used in conjunction with \fB\-E\fR, any \&\fB\-o\fR switch is understood to specify the dependency output file -(but \f(CW@pxref\fR{\-MF}), but if used without \fB\-E\fR, each \fB\-o\fR +(but \f(CW@pxref\fR{dashMF,,\-MF}), but if used without \fB\-E\fR, each \fB\-o\fR is understood to specify a target object file. .Sp Since \fB\-E\fR is not implied, \fB\-MD\fR can be used to generate a dependency output file as a side-effect of the compilation process. -.Ip "\fB\-MMD\fR" 4 +.IP "\fB\-MMD\fR" 4 .IX Item "-MMD" Like \fB\-MD\fR except mention only user header files, not system \&\-header files. -.Ip "\fB\-x c\fR" 4 +.IP "\fB\-x c\fR" 4 .IX Item "-x c" .PD 0 -.Ip "\fB\-x c++\fR" 4 +.IP "\fB\-x c++\fR" 4 .IX Item "-x c++" -.Ip "\fB\-x objective-c\fR" 4 +.IP "\fB\-x objective-c\fR" 4 .IX Item "-x objective-c" -.Ip "\fB\-x assembler-with-cpp\fR" 4 +.IP "\fB\-x assembler-with-cpp\fR" 4 .IX Item "-x assembler-with-cpp" .PD -Specify the source language: C, \*(C+, Objective-C, or assembly. This has +Specify the source language: C, \*(C+, Objective\-C, or assembly. This has nothing to do with standards conformance or extensions; it merely selects which base syntax to expect. If you give none of these options, cpp will deduce the language from the extension of the source file: @@ -449,89 +504,97 @@ generic mode. which selected both the language and the standards conformance level. This option has been removed, because it conflicts with the \fB\-l\fR option. -.Ip "\fB\-std=\fR\fIstandard\fR" 4 +.IP "\fB\-std=\fR\fIstandard\fR" 4 .IX Item "-std=standard" .PD 0 -.Ip "\fB\-ansi\fR" 4 +.IP "\fB\-ansi\fR" 4 .IX Item "-ansi" .PD -Specify the standard to which the code should conform. Currently cpp -only knows about the standards for C; other language standards will be -added in the future. +Specify the standard to which the code should conform. Currently \s-1CPP\s0 +knows about C and \*(C+ standards; others may be added in the future. .Sp \&\fIstandard\fR may be one of: .RS 4 -.if n .Ip "\f(CW""""iso9899:1990""""\fR" 4 -.el .Ip "\f(CWiso9899:1990\fR" 4 +.ie n .IP """iso9899:1990""" 4 +.el .IP "\f(CWiso9899:1990\fR" 4 .IX Item "iso9899:1990" .PD 0 -.if n .Ip "\f(CW""""c89""""\fR" 4 -.el .Ip "\f(CWc89\fR" 4 +.ie n .IP """c89""" 4 +.el .IP "\f(CWc89\fR" 4 .IX Item "c89" .PD The \s-1ISO\s0 C standard from 1990. \fBc89\fR is the customary shorthand for this version of the standard. .Sp The \fB\-ansi\fR option is equivalent to \fB\-std=c89\fR. -.if n .Ip "\f(CW""""iso9899:199409""""\fR" 4 -.el .Ip "\f(CWiso9899:199409\fR" 4 +.ie n .IP """iso9899:199409""" 4 +.el .IP "\f(CWiso9899:199409\fR" 4 .IX Item "iso9899:199409" The 1990 C standard, as amended in 1994. -.if n .Ip "\f(CW""""iso9899:1999""""\fR" 4 -.el .Ip "\f(CWiso9899:1999\fR" 4 +.ie n .IP """iso9899:1999""" 4 +.el .IP "\f(CWiso9899:1999\fR" 4 .IX Item "iso9899:1999" .PD 0 -.if n .Ip "\f(CW""""c99""""\fR" 4 -.el .Ip "\f(CWc99\fR" 4 +.ie n .IP """c99""" 4 +.el .IP "\f(CWc99\fR" 4 .IX Item "c99" -.if n .Ip "\f(CW""""iso9899:199x""""\fR" 4 -.el .Ip "\f(CWiso9899:199x\fR" 4 +.ie n .IP """iso9899:199x""" 4 +.el .IP "\f(CWiso9899:199x\fR" 4 .IX Item "iso9899:199x" -.if n .Ip "\f(CW""""c9x""""\fR" 4 -.el .Ip "\f(CWc9x\fR" 4 +.ie n .IP """c9x""" 4 +.el .IP "\f(CWc9x\fR" 4 .IX Item "c9x" .PD The revised \s-1ISO\s0 C standard, published in December 1999. Before publication, this was known as C9X. -.if n .Ip "\f(CW""""gnu89""""\fR" 4 -.el .Ip "\f(CWgnu89\fR" 4 +.ie n .IP """gnu89""" 4 +.el .IP "\f(CWgnu89\fR" 4 .IX Item "gnu89" The 1990 C standard plus \s-1GNU\s0 extensions. This is the default. -.if n .Ip "\f(CW""""gnu99""""\fR" 4 -.el .Ip "\f(CWgnu99\fR" 4 +.ie n .IP """gnu99""" 4 +.el .IP "\f(CWgnu99\fR" 4 .IX Item "gnu99" .PD 0 -.if n .Ip "\f(CW""""gnu9x""""\fR" 4 -.el .Ip "\f(CWgnu9x\fR" 4 +.ie n .IP """gnu9x""" 4 +.el .IP "\f(CWgnu9x\fR" 4 .IX Item "gnu9x" .PD The 1999 C standard plus \s-1GNU\s0 extensions. +.ie n .IP """c++98""" 4 +.el .IP "\f(CWc++98\fR" 4 +.IX Item "c++98" +The 1998 \s-1ISO\s0 \*(C+ standard plus amendments. +.ie n .IP """gnu++98""" 4 +.el .IP "\f(CWgnu++98\fR" 4 +.IX Item "gnu++98" +The same as \fB\-std=c++98\fR plus \s-1GNU\s0 extensions. This is the +default for \*(C+ code. .RE .RS 4 .RE -.Ip "\fB\-I-\fR" 4 +.IP "\fB\-I\-\fR" 4 .IX Item "-I-" Split the include path. Any directories specified with \fB\-I\fR -options before \fB\-I-\fR are searched only for headers requested with +options before \fB\-I\-\fR are searched only for headers requested with \&\f(CW\*(C`#include\ "\f(CIfile\f(CW"\*(C'\fR; they are not searched for \&\f(CW\*(C`#include\ <\f(CIfile\f(CW>\*(C'\fR. If additional directories are -specified with \fB\-I\fR options after the \fB\-I-\fR, those +specified with \fB\-I\fR options after the \fB\-I\-\fR, those directories are searched for all \fB#include\fR directives. .Sp -In addition, \fB\-I-\fR inhibits the use of the directory of the current +In addition, \fB\-I\-\fR inhibits the use of the directory of the current file directory as the first search directory for \f(CW\*(C`#include\ "\f(CIfile\f(CW"\*(C'\fR. -.Ip "\fB\-nostdinc\fR" 4 +.IP "\fB\-nostdinc\fR" 4 .IX Item "-nostdinc" Do not search the standard system directories for header files. Only the directories you have specified with \fB\-I\fR options (and the directory of the current file, if appropriate) are searched. -.Ip "\fB\-nostdinc++\fR" 4 +.IP "\fB\-nostdinc++\fR" 4 .IX Item "-nostdinc++" Do not search for header files in the \*(C+\-specific standard directories, but do still search the other standard directories. (This option is used when building the \*(C+ library.) -.Ip "\fB\-include\fR \fIfile\fR" 4 +.IP "\fB\-include\fR \fIfile\fR" 4 .IX Item "-include file" Process \fIfile\fR as if \f(CW\*(C`#include "file"\*(C'\fR appeared as the first line of the primary source file. However, the first directory searched @@ -542,7 +605,7 @@ chain as normal. .Sp If multiple \fB\-include\fR options are given, the files are included in the order they appear on the command line. -.Ip "\fB\-imacros\fR \fIfile\fR" 4 +.IP "\fB\-imacros\fR \fIfile\fR" 4 .IX Item "-imacros file" Exactly like \fB\-include\fR, except that any output produced by scanning \fIfile\fR is thrown away. Macros it defines remain defined. @@ -551,35 +614,37 @@ processing its declarations. .Sp All files specified by \fB\-imacros\fR are processed before all files specified by \fB\-include\fR. -.Ip "\fB\-idirafter\fR \fIdir\fR" 4 +.IP "\fB\-idirafter\fR \fIdir\fR" 4 .IX Item "-idirafter dir" Search \fIdir\fR for header files, but do it \fIafter\fR all directories specified with \fB\-I\fR and the standard system directories have been exhausted. \fIdir\fR is treated as a system include directory. -.Ip "\fB\-iprefix\fR \fIprefix\fR" 4 +.IP "\fB\-iprefix\fR \fIprefix\fR" 4 .IX Item "-iprefix prefix" Specify \fIprefix\fR as the prefix for subsequent \fB\-iwithprefix\fR options. If the prefix represents a directory, you should include the final \fB/\fR. -.Ip "\fB\-iwithprefix\fR \fIdir\fR" 4 +.IP "\fB\-iwithprefix\fR \fIdir\fR" 4 .IX Item "-iwithprefix dir" .PD 0 -.Ip "\fB\-iwithprefixbefore\fR \fIdir\fR" 4 +.IP "\fB\-iwithprefixbefore\fR \fIdir\fR" 4 .IX Item "-iwithprefixbefore dir" .PD Append \fIdir\fR to the prefix specified previously with \&\fB\-iprefix\fR, and add the resulting directory to the include search path. \fB\-iwithprefixbefore\fR puts it in the same place \fB\-I\fR would; \fB\-iwithprefix\fR puts it where \fB\-idirafter\fR would. -.Sp -Use of these options is discouraged. -.Ip "\fB\-isystem\fR \fIdir\fR" 4 +.IP "\fB\-isystem\fR \fIdir\fR" 4 .IX Item "-isystem dir" Search \fIdir\fR for header files, after all directories specified by \&\fB\-I\fR but before the standard system directories. Mark it as a system directory, so that it gets the same special treatment as is applied to the standard system directories. -.Ip "\fB\-fpreprocessed\fR" 4 +.IP "\fB\-fdollars\-in\-identifiers\fR" 4 +.IX Item "-fdollars-in-identifiers" +@anchor{fdollars\-in\-identifiers} +Accept \fB$\fR in identifiers. +.IP "\fB\-fpreprocessed\fR" 4 .IX Item "-fpreprocessed" Indicate to the preprocessor that the input file has already been preprocessed. This suppresses things like macro expansion, trigraph @@ -592,35 +657,65 @@ a tokenizer for the front ends. \&\fB\-fpreprocessed\fR is implicit if the input file has one of the extensions \fB.i\fR, \fB.ii\fR or \fB.mi\fR. These are the extensions that \s-1GCC\s0 uses for preprocessed files created by -\&\fB\-save-temps\fR. -.Ip "\fB\-ftabstop=\fR\fIwidth\fR" 4 +\&\fB\-save\-temps\fR. +.IP "\fB\-ftabstop=\fR\fIwidth\fR" 4 .IX Item "-ftabstop=width" Set the distance between tab stops. This helps the preprocessor report correct column numbers in warnings or errors, even if tabs appear on the line. If the value is less than 1 or greater than 100, the option is ignored. The default is 8. -.Ip "\fB\-fno-show-column\fR" 4 +.IP "\fB\-fexec\-charset=\fR\fIcharset\fR" 4 +.IX Item "-fexec-charset=charset" +Set the execution character set, used for string and character +constants. The default is \s-1UTF\-8\s0. \fIcharset\fR can be any encoding +supported by the system's \f(CW\*(C`iconv\*(C'\fR library routine. +.IP "\fB\-fwide\-exec\-charset=\fR\fIcharset\fR" 4 +.IX Item "-fwide-exec-charset=charset" +Set the wide execution character set, used for wide string and +character constants. The default is \s-1UTF\-32\s0 or \s-1UTF\-16\s0, whichever +corresponds to the width of \f(CW\*(C`wchar_t\*(C'\fR. As with +\&\fB\-ftarget\-charset\fR, \fIcharset\fR can be any encoding supported +by the system's \f(CW\*(C`iconv\*(C'\fR library routine; however, you will have +problems with encodings that do not fit exactly in \f(CW\*(C`wchar_t\*(C'\fR. +.IP "\fB\-finput\-charset=\fR\fIcharset\fR" 4 +.IX Item "-finput-charset=charset" +Set the input character set, used for translation from the character +set of the input file to the source character set used by \s-1GCC\s0. If the +locale does not specify, or \s-1GCC\s0 cannot get this information from the +locale, the default is \s-1UTF\-8\s0. This can be overridden by either the locale +or this command line option. Currently the command line option takes +precedence if there's a conflict. \fIcharset\fR can be any encoding +supported by the system's \f(CW\*(C`iconv\*(C'\fR library routine. +.IP "\fB\-fworking\-directory\fR" 4 +.IX Item "-fworking-directory" +Enable generation of linemarkers in the preprocessor output that will +let the compiler know the current working directory at the time of +preprocessing. When this option is enabled, the preprocessor will +emit, after the initial linemarker, a second linemarker with the +current working directory followed by two slashes. \s-1GCC\s0 will use this +directory, when it's present in the preprocessed input, as the +directory emitted as the current working directory in some debugging +information formats. This option is implicitly enabled if debugging +information is enabled, but this can be inhibited with the negated +form \fB\-fno\-working\-directory\fR. If the \fB\-P\fR flag is +present in the command line, this option has no effect, since no +\&\f(CW\*(C`#line\*(C'\fR directives are emitted whatsoever. +.IP "\fB\-fno\-show\-column\fR" 4 .IX Item "-fno-show-column" Do not print column numbers in diagnostics. This may be necessary if diagnostics are being scanned by a program that does not understand the column numbers, such as \fBdejagnu\fR. -.Ip "\fB\-A\fR \fIpredicate\fR\fB=\fR\fIanswer\fR" 4 +.IP "\fB\-A\fR \fIpredicate\fR\fB=\fR\fIanswer\fR" 4 .IX Item "-A predicate=answer" Make an assertion with the predicate \fIpredicate\fR and answer \&\fIanswer\fR. This form is preferred to the older form \fB\-A\fR \&\fIpredicate\fR\fB(\fR\fIanswer\fR\fB)\fR, which is still supported, because it does not use shell special characters. -.Ip "\fB\-A -\fR\fIpredicate\fR\fB=\fR\fIanswer\fR" 4 +.IP "\fB\-A \-\fR\fIpredicate\fR\fB=\fR\fIanswer\fR" 4 .IX Item "-A -predicate=answer" Cancel an assertion with the predicate \fIpredicate\fR and answer \&\fIanswer\fR. -.Ip "\fB\-A-\fR" 4 -.IX Item "-A-" -Cancel all predefined assertions and all assertions preceding it on -the command line. Also, undefine all predefined macros and all -macros preceding it on the command line. (This is a historical wart and -may change in the future.) -.Ip "\fB\-dCHARS\fR" 4 +.IP "\fB\-dCHARS\fR" 4 .IX Item "-dCHARS" \&\fI\s-1CHARS\s0\fR is a sequence of one or more of the following characters, and must not be preceded by a space. Other characters are interpreted @@ -628,7 +723,7 @@ by the compiler proper, or reserved for future versions of \s-1GCC\s0, and so are silently ignored. If you specify characters whose behavior conflicts, the result is undefined. .RS 4 -.Ip "\fBM\fR" 4 +.IP "\fBM\fR" 4 .IX Item "M" Instead of the normal output, generate a list of \fB#define\fR directives for all the macros defined during the execution of the @@ -639,30 +734,31 @@ Assuming you have no file \fIfoo.h\fR, the command .Vb 1 \& touch foo.h; cpp -dM foo.h .Ve +.Sp will show all the predefined macros. -.Ip "\fBD\fR" 4 +.IP "\fBD\fR" 4 .IX Item "D" Like \fBM\fR except in two respects: it does \fInot\fR include the predefined macros, and it outputs \fIboth\fR the \fB#define\fR directives and the result of preprocessing. Both kinds of output go to the standard output file. -.Ip "\fBN\fR" 4 +.IP "\fBN\fR" 4 .IX Item "N" Like \fBD\fR, but emit only the macro names, not their expansions. -.Ip "\fBI\fR" 4 +.IP "\fBI\fR" 4 .IX Item "I" Output \fB#include\fR directives in addition to the result of preprocessing. .RE .RS 4 .RE -.Ip "\fB\-P\fR" 4 +.IP "\fB\-P\fR" 4 .IX Item "-P" Inhibit generation of linemarkers in the output from the preprocessor. This might be useful when running the preprocessor on something that is not C code, and will be sent to a program which might be confused by the linemarkers. -.Ip "\fB\-C\fR" 4 +.IP "\fB\-C\fR" 4 .IX Item "-C" Do not discard comments. All comments are passed through to the output file, except for comments in processed directives, which are deleted @@ -673,52 +769,54 @@ causes the preprocessor to treat comments as tokens in their own right. For example, comments appearing at the start of what would be a directive line have the effect of turning that line into an ordinary source line, since the first token on the line is no longer a \fB#\fR. -.Ip "\fB\-gcc\fR" 4 -.IX Item "-gcc" -Define the macros _\|_GNUC_\|_, _\|_GNUC_MINOR_\|_ and -_\|_GNUC_PATCHLEVEL_\|_. These are defined automatically when you use -\&\fBgcc \-E\fR; you can turn them off in that case with -\&\fB\-no-gcc\fR. -.Ip "\fB\-traditional\fR" 4 -.IX Item "-traditional" -Try to imitate the behavior of old-fashioned C, as opposed to \s-1ISO\s0 -C. -.Ip "\fB\-trigraphs\fR" 4 +.IP "\fB\-CC\fR" 4 +.IX Item "-CC" +Do not discard comments, including during macro expansion. This is +like \fB\-C\fR, except that comments contained within macros are +also passed through to the output file where the macro is expanded. +.Sp +In addition to the side-effects of the \fB\-C\fR option, the +\&\fB\-CC\fR option causes all \*(C+\-style comments inside a macro +to be converted to C\-style comments. This is to prevent later use +of that macro from inadvertently commenting out the remainder of +the source line. +.Sp +The \fB\-CC\fR option is generally used to support lint comments. +.IP "\fB\-traditional\-cpp\fR" 4 +.IX Item "-traditional-cpp" +Try to imitate the behavior of old-fashioned C preprocessors, as +opposed to \s-1ISO\s0 C preprocessors. +.IP "\fB\-trigraphs\fR" 4 .IX Item "-trigraphs" Process trigraph sequences. -.Ip "\fB\-remap\fR" 4 +.IP "\fB\-remap\fR" 4 .IX Item "-remap" Enable special code to work around file systems which only permit very -short file names, such as \s-1MS-DOS\s0. -.Ip "\fB\-$\fR" 4 -.IX Item "-$" -Forbid the use of \fB$\fR in identifiers. The C standard allows -implementations to define extra characters that can appear in -identifiers. By default \s-1GNU\s0 \s-1CPP\s0 permits \fB$\fR, a common extension. -.Ip "\fB\-h\fR" 4 -.IX Item "-h" +short file names, such as \s-1MS\-DOS\s0. +.IP "\fB\-\-help\fR" 4 +.IX Item "--help" .PD 0 -.Ip "\fB\*(--help\fR" 4 -.IX Item "help" -.Ip "\fB\*(--target-help\fR" 4 -.IX Item "target-help" +.IP "\fB\-\-target\-help\fR" 4 +.IX Item "--target-help" .PD Print text describing all the command line options instead of preprocessing anything. -.Ip "\fB\-v\fR" 4 +.IP "\fB\-v\fR" 4 .IX Item "-v" Verbose mode. Print out \s-1GNU\s0 \s-1CPP\s0's version number at the beginning of execution, and report the final form of the include path. -.Ip "\fB\-H\fR" 4 +.IP "\fB\-H\fR" 4 .IX Item "-H" Print the name of each header file used, in addition to other normal activities. Each name is indented to show how deep in the -\&\fB#include\fR stack it is. -.Ip "\fB\-version\fR" 4 +\&\fB#include\fR stack it is. Precompiled header files are also +printed, even if they are found to be invalid; an invalid precompiled +header file is printed with \fB...x\fR and a valid one with \fB...!\fR . +.IP "\fB\-version\fR" 4 .IX Item "-version" .PD 0 -.Ip "\fB\*(--version\fR" 4 -.IX Item "version" +.IP "\fB\-\-version\fR" 4 +.IX Item "--version" .PD Print out \s-1GNU\s0 \s-1CPP\s0's version number. With one dash, proceed to preprocess as normal. With two dashes, exit immediately. @@ -733,25 +831,25 @@ Note that you can also specify places to search using options such as \&\fB\-M\fR. These take precedence over environment variables, which in turn take precedence over the configuration of \s-1GCC\s0. -.Ip "\fB\s-1CPATH\s0\fR" 4 +.IP "\fB\s-1CPATH\s0\fR" 4 .IX Item "CPATH" .PD 0 -.Ip "\fBC_INCLUDE_PATH\fR" 4 +.IP "\fBC_INCLUDE_PATH\fR" 4 .IX Item "C_INCLUDE_PATH" -.Ip "\fB\s-1CPLUS_INCLUDE_PATH\s0\fR" 4 +.IP "\fB\s-1CPLUS_INCLUDE_PATH\s0\fR" 4 .IX Item "CPLUS_INCLUDE_PATH" -.Ip "\fB\s-1OBJC_INCLUDE_PATH\s0\fR" 4 +.IP "\fB\s-1OBJC_INCLUDE_PATH\s0\fR" 4 .IX Item "OBJC_INCLUDE_PATH" .PD Each variable's value is a list of directories separated by a special character, much like \fB\s-1PATH\s0\fR, in which to look for header files. The special character, \f(CW\*(C`PATH_SEPARATOR\*(C'\fR, is target-dependent and -determined at \s-1GCC\s0 build time. For Windows-based targets it is a +determined at \s-1GCC\s0 build time. For Microsoft Windows-based targets it is a semicolon, and for almost all other targets it is a colon. .Sp \&\fB\s-1CPATH\s0\fR specifies a list of directories to be searched as if specified with \fB\-I\fR, but after any paths given with \fB\-I\fR -options on the command line. The environment variable is used +options on the command line. This environment variable is used regardless of which language is being preprocessed. .Sp The remaining environment variables apply only when preprocessing the @@ -759,10 +857,13 @@ particular language indicated. Each specifies a list of directories to be searched as if specified with \fB\-isystem\fR, but after any paths given with \fB\-isystem\fR options on the command line. .Sp -See also \f(CW@ref\fR{Search Path}. -.Ip "\fB\s-1DEPENDENCIES_OUTPUT\s0\fR" 4 +In all these variables, an empty element instructs the compiler to +search its current working directory. Empty elements can appear at the +beginning or end of a path. For instance, if the value of +\&\fB\s-1CPATH\s0\fR is \f(CW\*(C`:/special/include\*(C'\fR, that has the same +effect as \fB\-I.\ \-I/special/include\fR. +.IP "\fB\s-1DEPENDENCIES_OUTPUT\s0\fR" 4 .IX Item "DEPENDENCIES_OUTPUT" -@anchor{\s-1DEPENDENCIES_OUTPUT\s0} If this variable is set, its value specifies how to output dependencies for Make based on the non-system header files processed by the compiler. System header files are ignored in the dependency @@ -777,22 +878,21 @@ file \fIfile\fR using \fItarget\fR as the target name. In other words, this environment variable is equivalent to combining the options \fB\-MM\fR and \fB\-MF\fR, with an optional \fB\-MT\fR switch too. -.Ip "\fB\s-1SUNPRO_DEPENDENCIES\s0\fR" 4 +.IP "\fB\s-1SUNPRO_DEPENDENCIES\s0\fR" 4 .IX Item "SUNPRO_DEPENDENCIES" -This variable is the same as the environment variable -\&\fB\s-1DEPENDENCIES_OUTPUT\s0\fR, except that -system header files are not ignored, so it implies \fB\-M\fR rather -than \fB\-MM\fR. However, the dependence on the main input file is -omitted. +This variable is the same as \fB\s-1DEPENDENCIES_OUTPUT\s0\fR (see above), +except that system header files are not ignored, so it implies +\&\fB\-M\fR rather than \fB\-MM\fR. However, the dependence on the +main input file is omitted. .SH "SEE ALSO" .IX Header "SEE ALSO" -\&\fIgpl\fR\|(7), \fIgfdl\fR\|(7), \fIfsf-funding\fR\|(7), +\&\fIgpl\fR\|(7), \fIgfdl\fR\|(7), \fIfsf\-funding\fR\|(7), \&\fIgcc\fR\|(1), \fIas\fR\|(1), \fIld\fR\|(1), and the Info entries for \fIcpp\fR, \fIgcc\fR, and \&\fIbinutils\fR. .SH "COPYRIGHT" .IX Header "COPYRIGHT" Copyright (c) 1987, 1989, 1991, 1992, 1993, 1994, 1995, 1996, -1997, 1998, 1999, 2000, 2001 +1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc. .PP Permission is granted to copy, distribute and/or modify this document @@ -808,6 +908,7 @@ This manual contains no Invariant Sections. The Front-Cover Texts are .Vb 1 \& A GNU Manual .Ve +.PP (b) The \s-1FSF\s0's Back-Cover Text is: .PP .Vb 3 diff --git a/contrib/gcc/doc/gcc.1 b/contrib/gcc/doc/gcc.1 index 16a2b28..1fd2c2b 100644 --- a/contrib/gcc/doc/gcc.1 +++ b/contrib/gcc/doc/gcc.1 @@ -1,8 +1,7 @@ -.\" Automatically generated by Pod::Man version 1.15 -.\" Wed Feb 5 03:13:56 2003 +.\" Automatically generated by Pod::Man v1.37, Pod::Parser v1.14 .\" .\" Standard preamble: -.\" ====================================================================== +.\" ======================================================================== .de Sh \" Subsection heading .br .if t .Sp @@ -15,12 +14,6 @@ .if t .sp .5v .if n .sp .. -.de Ip \" List item -.br -.ie \\n(.$>=3 .ne \\$3 -.el .ne 3 -.IP "\\$1" \\$2 -.. .de Vb \" Begin verbatim text .ft CW .nf @@ -28,15 +21,14 @@ .. .de Ve \" End verbatim text .ft R - .fi .. .\" Set up some character translations and predefined strings. \*(-- will .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left .\" double quote, and \*(R" will give a right double quote. | will give a -.\" real vertical bar. \*(C+ will give a nicer C++. Capital omega is used -.\" to do unbreakable dashes and therefore won't be available. \*(C` and -.\" \*(C' expand to `' in nroff, nothing in troff, for use with C<> +.\" real vertical bar. \*(C+ will give a nicer C++. Capital omega is used to +.\" do unbreakable dashes and therefore won't be available. \*(C` and \*(C' +.\" expand to `' in nroff, nothing in troff, for use with C<>. .tr \(*W-|\(bv\*(Tr .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' .ie n \{\ @@ -56,10 +48,10 @@ . ds R" '' 'br\} .\" -.\" If the F register is turned on, we'll generate index entries on stderr -.\" for titles (.TH), headers (.SH), subsections (.Sh), items (.Ip), and -.\" index entries marked with X<> in POD. Of course, you'll have to process -.\" the output yourself in some meaningful fashion. +.\" If the F register is turned on, we'll generate index entries on stderr for +.\" titles (.TH), headers (.SH), subsections (.Sh), items (.Ip), and index +.\" entries marked with X<> in POD. Of course, you'll have to process the +.\" output yourself in some meaningful fashion. .if \nF \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" @@ -68,14 +60,13 @@ . rr F .\} .\" -.\" For nroff, turn off justification. Always turn off hyphenation; it -.\" makes way too many mistakes in technical documents. +.\" For nroff, turn off justification. Always turn off hyphenation; it makes +.\" way too many mistakes in technical documents. .hy 0 .if n .na .\" .\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2). .\" Fear. Run. Save yourself. No user-serviceable parts. -.bd B 3 . \" fudge factors for nroff and troff .if n \{\ . ds #H 0 @@ -135,13 +126,12 @@ . ds Ae AE .\} .rm #[ #] #H #V #F C -.\" ====================================================================== +.\" ======================================================================== .\" .IX Title "GCC 1" -.TH GCC 1 "gcc-3.2.2" "2003-02-05" "GNU" -.UC +.TH GCC 1 "2006-03-06" "gcc-3.4.6" "GNU" .SH "NAME" -gcc \- \s-1GNU\s0 project C and \*(C+ compiler +gcc \- GNU project C and C++ compiler .SH "SYNOPSIS" .IX Header "SYNOPSIS" gcc [\fB\-c\fR|\fB\-S\fR|\fB\-E\fR] [\fB\-std=\fR\fIstandard\fR] @@ -183,10 +173,10 @@ of the same kind; for example, if you specify \fB\-L\fR more than once, the directories are searched in the order specified. .PP Many options have long names starting with \fB\-f\fR or with -\&\fB\-W\fR\-\-\-for example, \fB\-fforce-mem\fR, -\&\fB\-fstrength-reduce\fR, \fB\-Wformat\fR and so on. Most of +\&\fB\-W\fR\-\-\-for example, \fB\-fforce\-mem\fR, +\&\fB\-fstrength\-reduce\fR, \fB\-Wformat\fR and so on. Most of these have both positive and negative forms; the negative form of -\&\fB\-ffoo\fR would be \fB\-fno-foo\fR. This manual documents +\&\fB\-ffoo\fR would be \fB\-fno\-foo\fR. This manual documents only one of these two forms, whichever one is not the default. .SH "OPTIONS" .IX Header "OPTIONS" @@ -194,623 +184,645 @@ only one of these two forms, whichever one is not the default. .IX Subsection "Option Summary" Here is a summary of all the options, grouped by type. Explanations are in the following sections. -.Ip "\fIOverall Options\fR" 4 +.IP "\fIOverall Options\fR" 4 .IX Item "Overall Options" -\&\fB\-c \-S \-E \-o\fR \fIfile\fR \fB\-pipe \-pass-exit-codes \-x\fR \fIlanguage\fR -\&\fB\-v \-### \-\-help \-\-target-help \-\-version\fR -.Ip "\fIC Language Options\fR" 4 +\&\fB\-c \-S \-E \-o\fR \fIfile\fR \fB\-pipe \-pass\-exit\-codes +\&\-x\fR \fIlanguage\fR \fB\-v \-### \-\-help \-\-target\-help \-\-version\fR +.IP "\fIC Language Options\fR" 4 .IX Item "C Language Options" -\&\fB\-ansi \-std=\fR\fIstandard\fR \fB\-aux-info\fR \fIfilename\fR -\&\fB\-fno-asm \-fno-builtin \-fno-builtin-\fR\fIfunction\fR -\&\fB\-fhosted \-ffreestanding -\&\-trigraphs \-no-integrated-cpp \-traditional \-traditional-cpp -\&\-fallow-single-precision \-fcond-mismatch -\&\-fsigned-bitfields \-fsigned-char -\&\-funsigned-bitfields \-funsigned-char -\&\-fwritable-strings\fR -.Ip "\fI\*(C+ Language Options\fR" 4 +\&\fB\-ansi \-std=\fR\fIstandard\fR \fB\-aux\-info\fR \fIfilename\fR +\&\fB\-fno\-asm \-fno\-builtin \-fno\-builtin\-\fR\fIfunction\fR +\&\fB\-fhosted \-ffreestanding \-fms\-extensions +\&\-trigraphs \-no\-integrated\-cpp \-traditional \-traditional\-cpp +\&\-fallow\-single\-precision \-fcond\-mismatch +\&\-fsigned\-bitfields \-fsigned\-char +\&\-funsigned\-bitfields \-funsigned\-char +\&\-fwritable\-strings\fR +.IP "\fI\*(C+ Language Options\fR" 4 .IX Item " Language Options" -\&\fB\-fno-access-control \-fcheck-new \-fconserve-space -\&\-fno-const-strings \-fdollars-in-identifiers -\&\-fno-elide-constructors -\&\-fno-enforce-eh-specs \-fexternal-templates -\&\-falt-external-templates -\&\-ffor-scope \-fno-for-scope \-fno-gnu-keywords -\&\-fno-implicit-templates -\&\-fno-implicit-inline-templates -\&\-fno-implement-inlines \-fms-extensions -\&\-fno-nonansi-builtins \-fno-operator-names -\&\-fno-optional-diags \-fpermissive -\&\-frepo \-fno-rtti \-fstats \-ftemplate-depth-\fR\fIn\fR -\&\fB\-fuse-cxa-atexit \-fvtable-gc \-fno-weak \-nostdinc++ -\&\-fno-default-inline \-Wabi \-Wctor-dtor-privacy -\&\-Wnon-virtual-dtor \-Wreorder -\&\-Weffc++ \-Wno-deprecated -\&\-Wno-non-template-friend \-Wold-style-cast -\&\-Woverloaded-virtual \-Wno-pmf-conversions -\&\-Wsign-promo \-Wsynth\fR -.Ip "\fIObjective-C Language Options\fR" 4 +\&\fB\-fabi\-version=\fR\fIn\fR \fB\-fno\-access\-control \-fcheck\-new +\&\-fconserve\-space \-fno\-const\-strings +\&\-fno\-elide\-constructors +\&\-fno\-enforce\-eh\-specs +\&\-ffor\-scope \-fno\-for\-scope \-fno\-gnu\-keywords +\&\-fno\-implicit\-templates +\&\-fno\-implicit\-inline\-templates +\&\-fno\-implement\-inlines \-fms\-extensions +\&\-fno\-nonansi\-builtins \-fno\-operator\-names +\&\-fno\-optional\-diags \-fpermissive +\&\-frepo \-fno\-rtti \-fstats \-ftemplate\-depth\-\fR\fIn\fR +\&\fB\-fuse\-cxa\-atexit \-fno\-weak \-nostdinc++ +\&\-fno\-default\-inline \-Wabi \-Wctor\-dtor\-privacy +\&\-Wnon\-virtual\-dtor \-Wreorder +\&\-Weffc++ \-Wno\-deprecated +\&\-Wno\-non\-template\-friend \-Wold\-style\-cast +\&\-Woverloaded\-virtual \-Wno\-pmf\-conversions +\&\-Wsign\-promo\fR +.IP "\fIObjective-C Language Options\fR" 4 .IX Item "Objective-C Language Options" -\&\fB\-fconstant-string-class=\fR\fIclass-name\fR -\&\fB\-fgnu-runtime \-fnext-runtime \-gen-decls -\&\-Wno-protocol \-Wselector\fR -.Ip "\fILanguage Independent Options\fR" 4 +\&\fB\-fconstant\-string\-class=\fR\fIclass-name\fR +\&\fB\-fgnu\-runtime \-fnext\-runtime +\&\-fno\-nil\-receivers +\&\-fobjc\-exceptions +\&\-freplace\-objc\-classes +\&\-fzero\-link +\&\-gen\-decls +\&\-Wno\-protocol \-Wselector \-Wundeclared\-selector\fR +.IP "\fILanguage Independent Options\fR" 4 .IX Item "Language Independent Options" -\&\fB\-fmessage-length=\fR\fIn\fR -\&\fB\-fdiagnostics-show-location=\fR[\fBonce\fR|\fBevery-line\fR] -.Ip "\fIWarning Options\fR" 4 +\&\fB\-fmessage\-length=\fR\fIn\fR +\&\fB\-fdiagnostics\-show\-location=\fR[\fBonce\fR|\fBevery-line\fR] +.IP "\fIWarning Options\fR" 4 .IX Item "Warning Options" -\&\fB\-fsyntax-only \-pedantic \-pedantic-errors -\&\-w \-W \-Wall \-Waggregate-return -\&\-Wcast-align \-Wcast-qual \-Wchar-subscripts \-Wcomment -\&\-Wconversion \-Wno-deprecated-declarations -\&\-Wdisabled-optimization \-Wdiv-by-zero \-Werror -\&\-Wfloat-equal \-Wformat \-Wformat=2 -\&\-Wformat-nonliteral \-Wformat-security -\&\-Wimplicit \-Wimplicit-int -\&\-Wimplicit-function-declaration -\&\-Werror-implicit-function-declaration -\&\-Wimport \-Winline -\&\-Wlarger-than-\fR\fIlen\fR \fB\-Wlong-long -\&\-Wmain \-Wmissing-braces -\&\-Wmissing-format-attribute \-Wmissing-noreturn -\&\-Wmultichar \-Wno-format-extra-args \-Wno-format-y2k -\&\-Wno-import \-Wpacked \-Wpadded -\&\-Wparentheses \-Wpointer-arith \-Wredundant-decls -\&\-Wreturn-type \-Wsequence-point \-Wshadow -\&\-Wsign-compare \-Wswitch \-Wsystem-headers -\&\-Wtrigraphs \-Wundef \-Wuninitialized -\&\-Wunknown-pragmas \-Wunreachable-code -\&\-Wunused \-Wunused-function \-Wunused-label \-Wunused-parameter -\&\-Wunused-value \-Wunused-variable \-Wwrite-strings\fR -.Ip "\fIC-only Warning Options\fR" 4 +\&\fB\-fsyntax\-only \-pedantic \-pedantic\-errors +\&\-w \-Wextra \-Wall \-Waggregate\-return +\&\-Wcast\-align \-Wcast\-qual \-Wchar\-subscripts \-Wcomment +\&\-Wconversion \-Wno\-deprecated\-declarations +\&\-Wdisabled\-optimization \-Wno\-div\-by\-zero \-Wendif\-labels +\&\-Werror \-Werror\-implicit\-function\-declaration +\&\-Wfloat\-equal \-Wformat \-Wformat=2 +\&\-Wno\-format\-extra\-args \-Wformat\-nonliteral +\&\-Wformat\-security \-Wformat\-y2k +\&\-Wimplicit \-Wimplicit\-function\-declaration \-Wimplicit\-int +\&\-Wimport \-Wno\-import \-Winit\-self \-Winline +\&\-Wno\-invalid\-offsetof \-Winvalid\-pch +\&\-Wlarger\-than\-\fR\fIlen\fR \fB\-Wlong\-long +\&\-Wmain \-Wmissing\-braces +\&\-Wmissing\-format\-attribute \-Wmissing\-noreturn +\&\-Wno\-multichar \-Wnonnull \-Wpacked \-Wpadded +\&\-Wparentheses \-Wpointer\-arith \-Wredundant\-decls +\&\-Wreturn\-type \-Wsequence\-point \-Wshadow +\&\-Wsign\-compare \-Wstrict\-aliasing +\&\-Wswitch \-Wswitch\-default \-Wswitch\-enum +\&\-Wsystem\-headers \-Wtrigraphs \-Wundef \-Wuninitialized +\&\-Wunknown\-pragmas \-Wunreachable\-code +\&\-Wunused \-Wunused\-function \-Wunused\-label \-Wunused\-parameter +\&\-Wunused\-value \-Wunused\-variable \-Wwrite\-strings\fR +.IP "\fIC\-only Warning Options\fR" 4 .IX Item "C-only Warning Options" -\&\fB\-Wbad-function-cast \-Wmissing-declarations -\&\-Wmissing-prototypes \-Wnested-externs -\&\-Wstrict-prototypes \-Wtraditional\fR -.Ip "\fIDebugging Options\fR" 4 +\&\fB\-Wbad\-function\-cast \-Wmissing\-declarations +\&\-Wmissing\-prototypes \-Wnested\-externs \-Wold\-style\-definition +\&\-Wstrict\-prototypes \-Wtraditional +\&\-Wdeclaration\-after\-statement\fR +.IP "\fIDebugging Options\fR" 4 .IX Item "Debugging Options" \&\fB\-d\fR\fIletters\fR \fB\-dumpspecs \-dumpmachine \-dumpversion -\&\-fdump-unnumbered \-fdump-translation-unit\fR[\fB-\fR\fIn\fR] -\&\fB\-fdump-class-hierarchy\fR[\fB-\fR\fIn\fR] -\&\fB\-fdump-tree-original\fR[\fB-\fR\fIn\fR] \fB\-fdump-tree-optimized\fR[\fB-\fR\fIn\fR] -\&\fB\-fdump-tree-inlined\fR[\fB-\fR\fIn\fR] -\&\fB\-fmem-report \-fpretend-float -\&\-fprofile-arcs \-fsched-verbose=\fR\fIn\fR -\&\fB\-ftest-coverage \-ftime-report -\&\-g \-g\fR\fIlevel\fR \fB\-gcoff \-gdwarf \-gdwarf-1 \-gdwarf-1+ \-gdwarf-2 +\&\-fdump\-unnumbered \-fdump\-translation\-unit\fR[\fB\-\fR\fIn\fR] +\&\fB\-fdump\-class\-hierarchy\fR[\fB\-\fR\fIn\fR] +\&\fB\-fdump\-tree\-original\fR[\fB\-\fR\fIn\fR] +\&\fB\-fdump\-tree\-optimized\fR[\fB\-\fR\fIn\fR] +\&\fB\-fdump\-tree\-inlined\fR[\fB\-\fR\fIn\fR] +\&\fB\-feliminate\-dwarf2\-dups \-feliminate\-unused\-debug\-types +\&\-feliminate\-unused\-debug\-symbols \-fmem\-report \-fprofile\-arcs +\&\-frandom\-seed=\fR\fIstring\fR \fB\-fsched\-verbose=\fR\fIn\fR +\&\fB\-ftest\-coverage \-ftime\-report +\&\-g \-g\fR\fIlevel\fR \fB\-gcoff \-gdwarf\-2 \&\-ggdb \-gstabs \-gstabs+ \-gvms \-gxcoff \-gxcoff+ -\&\-p \-pg \-print-file-name=\fR\fIlibrary\fR \fB\-print-libgcc-file-name -\&\-print-multi-directory \-print-multi-lib -\&\-print-prog-name=\fR\fIprogram\fR \fB\-print-search-dirs \-Q -\&\-save-temps \-time\fR -.Ip "\fIOptimization Options\fR" 4 +\&\-p \-pg \-print\-file\-name=\fR\fIlibrary\fR \fB\-print\-libgcc\-file\-name +\&\-print\-multi\-directory \-print\-multi\-lib +\&\-print\-prog\-name=\fR\fIprogram\fR \fB\-print\-search\-dirs \-Q +\&\-save\-temps \-time\fR +.IP "\fIOptimization Options\fR" 4 .IX Item "Optimization Options" -\&\fB\-falign-functions=\fR\fIn\fR \fB\-falign-jumps=\fR\fIn\fR -\&\fB\-falign-labels=\fR\fIn\fR \fB\-falign-loops=\fR\fIn\fR -\&\fB\-fbounds-check -\&\-fbranch-probabilities \-fcaller-saves \-fcprop-registers -\&\-fcse-follow-jumps \-fcse-skip-blocks \-fdata-sections -\&\-fdelayed-branch \-fdelete-null-pointer-checks -\&\-fexpensive-optimizations \-ffast-math \-ffloat-store -\&\-fforce-addr \-fforce-mem \-ffunction-sections -\&\-fgcse \-fgcse-lm \-fgcse-sm -\&\-finline-functions \-finline-limit=\fR\fIn\fR \fB\-fkeep-inline-functions -\&\-fkeep-static-consts \-fmerge-constants \-fmerge-all-constants -\&\-fmove-all-movables \-fno-branch-count-reg -\&\-fno-default-inline \-fno-defer-pop -\&\-fno-function-cse \-fno-guess-branch-probability -\&\-fno-inline \-fno-math-errno \-fno-peephole \-fno-peephole2 -\&\-funsafe-math-optimizations \-fno-trapping-math -\&\-fomit-frame-pointer \-foptimize-register-move -\&\-foptimize-sibling-calls \-fprefetch-loop-arrays -\&\-freduce-all-givs \-fregmove \-frename-registers -\&\-frerun-cse-after-loop \-frerun-loop-opt -\&\-fschedule-insns \-fschedule-insns2 -\&\-fno-sched-interblock \-fno-sched-spec -\&\-fsched-spec-load \-fsched-spec-load-dangerous -\&\-fsingle-precision-constant \-fssa \-fssa-ccp \-fssa-dce -\&\-fstrength-reduce \-fstrict-aliasing \-fthread-jumps -\&\-ftrapv \-funroll-all-loops \-funroll-loops +\&\fB\-falign\-functions=\fR\fIn\fR \fB\-falign\-jumps=\fR\fIn\fR +\&\fB\-falign\-labels=\fR\fIn\fR \fB\-falign\-loops=\fR\fIn\fR +\&\fB\-fbranch\-probabilities \-fprofile\-values \-fvpt \-fbranch\-target\-load\-optimize +\&\-fbranch\-target\-load\-optimize2 \-fcaller\-saves \-fcprop\-registers +\&\-fcse\-follow\-jumps \-fcse\-skip\-blocks \-fdata\-sections +\&\-fdelayed\-branch \-fdelete\-null\-pointer\-checks +\&\-fexpensive\-optimizations \-ffast\-math \-ffloat\-store +\&\-fforce\-addr \-fforce\-mem \-ffunction\-sections +\&\-fgcse \-fgcse\-lm \-fgcse\-sm \-fgcse\-las \-floop\-optimize +\&\-fcrossjumping \-fif\-conversion \-fif\-conversion2 +\&\-finline\-functions \-finline\-limit=\fR\fIn\fR \fB\-fkeep\-inline\-functions +\&\-fkeep\-static\-consts \-fmerge\-constants \-fmerge\-all\-constants +\&\-fmove\-all\-movables \-fnew\-ra \-fno\-branch\-count\-reg +\&\-fno\-default\-inline \-fno\-defer\-pop +\&\-fno\-function\-cse \-fno\-guess\-branch\-probability +\&\-fno\-inline \-fno\-math\-errno \-fno\-peephole \-fno\-peephole2 +\&\-funsafe\-math\-optimizations \-ffinite\-math\-only +\&\-fno\-trapping\-math \-fno\-zero\-initialized\-in\-bss +\&\-fomit\-frame\-pointer \-foptimize\-register\-move +\&\-foptimize\-sibling\-calls \-fprefetch\-loop\-arrays +\&\-fprofile\-generate \-fprofile\-use +\&\-freduce\-all\-givs \-fregmove \-frename\-registers +\&\-freorder\-blocks \-freorder\-functions +\&\-frerun\-cse\-after\-loop \-frerun\-loop\-opt +\&\-frounding\-math \-fschedule\-insns \-fschedule\-insns2 +\&\-fno\-sched\-interblock \-fno\-sched\-spec \-fsched\-spec\-load +\&\-fsched\-spec\-load\-dangerous +\&\-fsched\-stalled\-insns=\fR\fIn\fR \fB\-sched\-stalled\-insns\-dep=\fR\fIn\fR +\&\fB\-fsched2\-use\-superblocks +\&\-fsched2\-use\-traces \-fsignaling\-nans +\&\-fsingle\-precision\-constant +\&\-fstrength\-reduce \-fstrict\-aliasing \-ftracer \-fthread\-jumps +\&\-funroll\-all\-loops \-funroll\-loops \-fpeel\-loops +\&\-funswitch\-loops \-fold\-unroll\-loops \-fold\-unroll\-all\-loops \&\-\-param\fR \fIname\fR\fB=\fR\fIvalue\fR \&\fB\-O \-O0 \-O1 \-O2 \-O3 \-Os\fR -.Ip "\fIPreprocessor Options\fR" 4 +.IP "\fIPreprocessor Options\fR" 4 .IX Item "Preprocessor Options" -\&\fB\-$ \-A\fR\fIquestion\fR\fB=\fR\fIanswer\fR \fB\-A-\fR\fIquestion\fR[\fB=\fR\fIanswer\fR] +\&\fB\-A\fR\fIquestion\fR\fB=\fR\fIanswer\fR +\&\fB\-A\-\fR\fIquestion\fR[\fB=\fR\fIanswer\fR] \&\fB\-C \-dD \-dI \-dM \-dN \&\-D\fR\fImacro\fR[\fB=\fR\fIdefn\fR] \fB\-E \-H \&\-idirafter\fR \fIdir\fR \&\fB\-include\fR \fIfile\fR \fB\-imacros\fR \fIfile\fR \&\fB\-iprefix\fR \fIfile\fR \fB\-iwithprefix\fR \fIdir\fR \&\fB\-iwithprefixbefore\fR \fIdir\fR \fB\-isystem\fR \fIdir\fR -\&\fB\-M \-MM \-MF \-MG \-MP \-MQ \-MT \-nostdinc \-P \-remap -\&\-trigraphs \-undef \-U\fR\fImacro\fR \fB\-Wp,\fR\fIoption\fR -.Ip "\fIAssembler Option\fR" 4 +\&\fB\-M \-MM \-MF \-MG \-MP \-MQ \-MT \-nostdinc +\&\-P \-fworking\-directory \-remap +\&\-trigraphs \-undef \-U\fR\fImacro\fR \fB\-Wp,\fR\fIoption\fR +\&\fB\-Xpreprocessor\fR \fIoption\fR +.IP "\fIAssembler Option\fR" 4 .IX Item "Assembler Option" -\&\fB\-Wa,\fR\fIoption\fR -.Ip "\fILinker Options\fR" 4 +\&\fB\-Wa,\fR\fIoption\fR \fB\-Xassembler\fR \fIoption\fR +.IP "\fILinker Options\fR" 4 .IX Item "Linker Options" -\&\fB -\&\fR\fIobject-file-name\fR \fB\-l\fR\fIlibrary\fR -\&\fB\-nostartfiles \-nodefaultlibs \-nostdlib -\&\-s \-static \-static-libgcc \-shared \-shared-libgcc \-symbolic +\&\fIobject-file-name\fR \fB\-l\fR\fIlibrary\fR +\&\fB\-nostartfiles \-nodefaultlibs \-nostdlib \-pie +\&\-s \-static \-static\-libgcc \-shared \-shared\-libgcc \-symbolic \&\-Wl,\fR\fIoption\fR \fB\-Xlinker\fR \fIoption\fR \&\fB\-u\fR \fIsymbol\fR -.Ip "\fIDirectory Options\fR" 4 +.IP "\fIDirectory Options\fR" 4 .IX Item "Directory Options" -\&\fB\-B\fR\fIprefix\fR \fB\-I\fR\fIdir\fR \fB\-I- \-L\fR\fIdir\fR \fB\-specs=\fR\fIfile\fR -.Ip "\fITarget Options\fR" 4 +\&\fB\-B\fR\fIprefix\fR \fB\-I\fR\fIdir\fR \fB\-I\- \-L\fR\fIdir\fR \fB\-specs=\fR\fIfile\fR +.IP "\fITarget Options\fR" 4 .IX Item "Target Options" -\&\fB\-b\fR \fImachine\fR \fB\-V\fR \fIversion\fR -.Ip "\fIMachine Dependent Options\fR" 4 +\&\fB\-V\fR \fIversion\fR \fB\-b\fR \fImachine\fR +.IP "\fIMachine Dependent Options\fR" 4 .IX Item "Machine Dependent Options" \&\fIM680x0 Options\fR -.Sp \&\fB\-m68000 \-m68020 \-m68020\-40 \-m68020\-60 \-m68030 \-m68040 \&\-m68060 \-mcpu32 \-m5200 \-m68881 \-mbitfield \-mc68000 \-mc68020 -\&\-mfpa \-mnobitfield \-mrtd \-mshort \-msoft-float \-mpcrel -\&\-malign-int \-mstrict-align\fR +\&\-mnobitfield \-mrtd \-mshort \-msoft\-float \-mpcrel +\&\-malign\-int \-mstrict\-align \-msep\-data \-mno\-sep\-data +\&\-mshared\-library\-id=n \-mid\-shared\-library \-mno\-id\-shared\-library\fR .Sp \&\fIM68hc1x Options\fR -.Sp -\&\fB\-m6811 \-m6812 \-m68hc11 \-m68hc12 -\&\-mauto-incdec \-mshort \-msoft-reg-count=\fR\fIcount\fR +\&\fB\-m6811 \-m6812 \-m68hc11 \-m68hc12 \-m68hcs12 +\&\-mauto\-incdec \-minmax \-mlong\-calls \-mshort +\&\-msoft\-reg\-count=\fR\fIcount\fR .Sp \&\fI\s-1VAX\s0 Options\fR -.Sp \&\fB\-mg \-mgnu \-munix\fR .Sp \&\fI\s-1SPARC\s0 Options\fR -.Sp \&\fB\-mcpu=\fR\fIcpu-type\fR \&\fB\-mtune=\fR\fIcpu-type\fR \&\fB\-mcmodel=\fR\fIcode-model\fR -\&\fB\-m32 \-m64 -\&\-mapp-regs \-mbroken-saverestore \-mcypress -\&\-mfaster-structs \-mflat -\&\-mfpu \-mhard-float \-mhard-quad-float -\&\-mimpure-text \-mlive-g0 \-mno-app-regs -\&\-mno-faster-structs \-mno-flat \-mno-fpu -\&\-mno-impure-text \-mno-stack-bias \-mno-unaligned-doubles -\&\-msoft-float \-msoft-quad-float \-msparclite \-mstack-bias -\&\-msupersparc \-munaligned-doubles \-mv8\fR -.Sp -\&\fIConvex Options\fR -.Sp -\&\fB\-mc1 \-mc2 \-mc32 \-mc34 \-mc38 -\&\-margcount \-mnoargcount -\&\-mlong32 \-mlong64 -\&\-mvolatile-cache \-mvolatile-nocache\fR -.Sp -\&\fI\s-1AMD29K\s0 Options\fR -.Sp -\&\fB\-m29000 \-m29050 \-mbw \-mnbw \-mdw \-mndw -\&\-mlarge \-mnormal \-msmall -\&\-mkernel-registers \-mno-reuse-arg-regs -\&\-mno-stack-check \-mno-storem-bug -\&\-mreuse-arg-regs \-msoft-float \-mstack-check -\&\-mstorem-bug \-muser-registers\fR +\&\fB\-m32 \-m64 \-mapp\-regs \-mno\-app\-regs +\&\-mfaster\-structs \-mno\-faster\-structs +\&\-mflat \-mno\-flat \-mfpu \-mno\-fpu +\&\-mhard\-float \-msoft\-float +\&\-mhard\-quad\-float \-msoft\-quad\-float +\&\-mimpure\-text \-mno\-impure\-text \-mlittle\-endian +\&\-mstack\-bias \-mno\-stack\-bias +\&\-munaligned\-doubles \-mno\-unaligned\-doubles +\&\-mv8plus \-mno\-v8plus \-mvis \-mno\-vis +\&\-mcypress \-mf930 \-mf934 +\&\-msparclite \-msupersparc \-mv8 +\&\-threads \-pthreads\fR .Sp \&\fI\s-1ARM\s0 Options\fR -.Sp -\&\fB\-mapcs-frame \-mno-apcs-frame -\&\-mapcs-26 \-mapcs-32 -\&\-mapcs-stack-check \-mno-apcs-stack-check -\&\-mapcs-float \-mno-apcs-float -\&\-mapcs-reentrant \-mno-apcs-reentrant -\&\-msched-prolog \-mno-sched-prolog -\&\-mlittle-endian \-mbig-endian \-mwords-little-endian -\&\-malignment-traps \-mno-alignment-traps -\&\-msoft-float \-mhard-float \-mfpe -\&\-mthumb-interwork \-mno-thumb-interwork +\&\fB\-mapcs\-frame \-mno\-apcs\-frame +\&\-mapcs\-26 \-mapcs\-32 +\&\-mapcs\-stack\-check \-mno\-apcs\-stack\-check +\&\-mapcs\-float \-mno\-apcs\-float +\&\-mapcs\-reentrant \-mno\-apcs\-reentrant +\&\-msched\-prolog \-mno\-sched\-prolog +\&\-mlittle\-endian \-mbig\-endian \-mwords\-little\-endian +\&\-malignment\-traps \-mno\-alignment\-traps +\&\-msoft\-float \-mhard\-float \-mfpe +\&\-mthumb\-interwork \-mno\-thumb\-interwork \&\-mcpu=\fR\fIname\fR \fB\-march=\fR\fIname\fR \fB\-mfpe=\fR\fIname\fR -\&\fB\-mstructure-size-boundary=\fR\fIn\fR -\&\fB\-mbsd \-mxopen \-mno-symrename -\&\-mabort-on-noreturn -\&\-mlong-calls \-mno-long-calls -\&\-msingle-pic-base \-mno-single-pic-base -\&\-mpic-register=\fR\fIreg\fR -\&\fB\-mnop-fun-dllimport -\&\-mpoke-function-name +\&\fB\-mstructure\-size\-boundary=\fR\fIn\fR +\&\fB\-mabort\-on\-noreturn +\&\-mlong\-calls \-mno\-long\-calls +\&\-msingle\-pic\-base \-mno\-single\-pic\-base +\&\-mpic\-register=\fR\fIreg\fR +\&\fB\-mnop\-fun\-dllimport +\&\-mcirrus\-fix\-invalid\-insns \-mno\-cirrus\-fix\-invalid\-insns +\&\-mpoke\-function\-name \&\-mthumb \-marm -\&\-mtpcs-frame \-mtpcs-leaf-frame -\&\-mcaller-super-interworking \-mcallee-super-interworking\fR -.Sp -\&\fI\s-1MN10200\s0 Options\fR -.Sp -\&\fB\-mrelax\fR +\&\-mtpcs\-frame \-mtpcs\-leaf\-frame +\&\-mcaller\-super\-interworking \-mcallee\-super\-interworking\fR .Sp \&\fI\s-1MN10300\s0 Options\fR -.Sp -\&\fB\-mmult-bug \-mno-mult-bug -\&\-mam33 \-mno-am33 -\&\-mno-crt0 \-mrelax\fR +\&\fB\-mmult\-bug \-mno\-mult\-bug +\&\-mam33 \-mno\-am33 +\&\-mam33\-2 \-mno\-am33\-2 +\&\-mno\-crt0 \-mrelax\fR .Sp \&\fIM32R/D Options\fR -.Sp -\&\fB\-m32rx \-m32r \-mcode-model=\fR\fImodel-type\fR \fB\-msdata=\fR\fIsdata-type\fR +\&\fB\-m32r2 \-m32rx \-m32r +\&\-mdebug +\&\-malign\-loops \-mno\-align\-loops +\&\-missue\-rate=\fR\fInumber\fR +\&\fB\-mbranch\-cost=\fR\fInumber\fR +\&\fB\-mmodel=\fR\fIcode-size-model-type\fR +\&\fB\-msdata=\fR\fIsdata-type\fR +\&\fB\-mno\-flush\-func \-mflush\-func=\fR\fIname\fR +\&\fB\-mno\-flush\-trap \-mflush\-trap=\fR\fInumber\fR \&\fB\-G\fR \fInum\fR .Sp -\&\fIM88K Options\fR -.Sp -\&\fB\-m88000 \-m88100 \-m88110 \-mbig-pic -\&\-mcheck-zero-division \-mhandle-large-shift -\&\-midentify-revision \-mno-check-zero-division -\&\-mno-ocs-debug-info \-mno-ocs-frame-position -\&\-mno-optimize-arg-area \-mno-serialize-volatile -\&\-mno-underscores \-mocs-debug-info -\&\-mocs-frame-position \-moptimize-arg-area -\&\-mserialize-volatile \-mshort-data-\fR\fInum\fR \fB\-msvr3 -\&\-msvr4 \-mtrap-large-shift \-muse-div-instruction -\&\-mversion-03.00 \-mwarn-passed-structs\fR -.Sp \&\fI\s-1RS/6000\s0 and PowerPC Options\fR -.Sp \&\fB\-mcpu=\fR\fIcpu-type\fR \&\fB\-mtune=\fR\fIcpu-type\fR -\&\fB\-mpower \-mno-power \-mpower2 \-mno-power2 -\&\-mpowerpc \-mpowerpc64 \-mno-powerpc -\&\-maltivec \-mno-altivec -\&\-mpowerpc-gpopt \-mno-powerpc-gpopt -\&\-mpowerpc-gfxopt \-mno-powerpc-gfxopt -\&\-mnew-mnemonics \-mold-mnemonics -\&\-mfull-toc \-mminimal-toc \-mno-fp-in-toc \-mno-sum-in-toc -\&\-m64 \-m32 \-mxl-call \-mno-xl-call \-mpe -\&\-msoft-float \-mhard-float \-mmultiple \-mno-multiple -\&\-mstring \-mno-string \-mupdate \-mno-update -\&\-mfused-madd \-mno-fused-madd \-mbit-align \-mno-bit-align -\&\-mstrict-align \-mno-strict-align \-mrelocatable -\&\-mno-relocatable \-mrelocatable-lib \-mno-relocatable-lib -\&\-mtoc \-mno-toc \-mlittle \-mlittle-endian \-mbig \-mbig-endian -\&\-mcall-aix \-mcall-sysv \-mcall-netbsd -\&\-maix-struct-return \-msvr4\-struct-return -\&\-mabi=altivec \-mabi=no-altivec -\&\-mprototype \-mno-prototype -\&\-msim \-mmvme \-mads \-myellowknife \-memb \-msdata -\&\-msdata=\fR\fIopt\fR \fB\-mvxworks \-G\fR \fInum\fR \fB\-pthread\fR -.Sp -\&\fI\s-1RT\s0 Options\fR -.Sp -\&\fB\-mcall-lib-mul \-mfp-arg-in-fpregs \-mfp-arg-in-gregs -\&\-mfull-fp-blocks \-mhc-struct-return \-min-line-mul -\&\-mminimum-fp-blocks \-mnohc-struct-return\fR +\&\fB\-mpower \-mno\-power \-mpower2 \-mno\-power2 +\&\-mpowerpc \-mpowerpc64 \-mno\-powerpc +\&\-maltivec \-mno\-altivec +\&\-mpowerpc\-gpopt \-mno\-powerpc\-gpopt +\&\-mpowerpc\-gfxopt \-mno\-powerpc\-gfxopt +\&\-mnew\-mnemonics \-mold\-mnemonics +\&\-mfull\-toc \-mminimal\-toc \-mno\-fp\-in\-toc \-mno\-sum\-in\-toc +\&\-m64 \-m32 \-mxl\-compat \-mno\-xl\-compat \-mpe +\&\-malign\-power \-malign\-natural +\&\-msoft\-float \-mhard\-float \-mmultiple \-mno\-multiple +\&\-mstring \-mno\-string \-mupdate \-mno\-update +\&\-mfused\-madd \-mno\-fused\-madd \-mbit\-align \-mno\-bit\-align +\&\-mstrict\-align \-mno\-strict\-align \-mrelocatable +\&\-mno\-relocatable \-mrelocatable\-lib \-mno\-relocatable\-lib +\&\-mtoc \-mno\-toc \-mlittle \-mlittle\-endian \-mbig \-mbig\-endian +\&\-mdynamic\-no\-pic +\&\-mprioritize\-restricted\-insns=\fR\fIpriority\fR +\&\fB\-msched\-costly\-dep=\fR\fIdependence_type\fR +\&\fB\-minsert\-sched\-nops=\fR\fIscheme\fR +\&\fB\-mcall\-sysv \-mcall\-netbsd +\&\-maix\-struct\-return \-msvr4\-struct\-return +\&\-mabi=altivec \-mabi=no\-altivec +\&\-mabi=spe \-mabi=no\-spe +\&\-misel=yes \-misel=no +\&\-mspe=yes \-mspe=no +\&\-mfloat\-gprs=yes \-mfloat\-gprs=no +\&\-mprototype \-mno\-prototype +\&\-msim \-mmvme \-mads \-myellowknife \-memb \-msdata +\&\-msdata=\fR\fIopt\fR \fB\-mvxworks \-mwindiss \-G\fR \fInum\fR \fB\-pthread\fR +.Sp +\&\fIDarwin Options\fR +\&\fB\-all_load \-allowable_client \-arch \-arch_errors_fatal +\&\-arch_only \-bind_at_load \-bundle \-bundle_loader +\&\-client_name \-compatibility_version \-current_version +\&\-dependency\-file \-dylib_file \-dylinker_install_name +\&\-dynamic \-dynamiclib \-exported_symbols_list +\&\-filelist \-flat_namespace \-force_cpusubtype_ALL +\&\-force_flat_namespace \-headerpad_max_install_names +\&\-image_base \-init \-install_name \-keep_private_externs +\&\-multi_module \-multiply_defined \-multiply_defined_unused +\&\-noall_load \-nofixprebinding \-nomultidefs \-noprebind \-noseglinkedit +\&\-pagezero_size \-prebind \-prebind_all_twolevel_modules +\&\-private_bundle \-read_only_relocs \-sectalign +\&\-sectobjectsymbols \-whyload \-seg1addr +\&\-sectcreate \-sectobjectsymbols \-sectorder +\&\-seg_addr_table \-seg_addr_table_filename \-seglinkedit +\&\-segprot \-segs_read_only_addr \-segs_read_write_addr +\&\-single_module \-static \-sub_library \-sub_umbrella +\&\-twolevel_namespace \-umbrella \-undefined +\&\-unexported_symbols_list \-weak_reference_mismatches +\&\-whatsloaded\fR .Sp \&\fI\s-1MIPS\s0 Options\fR -.Sp -\&\fB\-mabicalls \-march=\fR\fIcpu-type\fR \fB\-mtune=\fR\fIcpu=type\fR -\&\fB\-mcpu=\fR\fIcpu-type\fR \fB\-membedded-data \-muninit-const-in-rodata -\&\-membedded-pic \-mfp32 \-mfp64 \-mfused-madd \-mno-fused-madd -\&\-mgas \-mgp32 \-mgp64 -\&\-mgpopt \-mhalf-pic \-mhard-float \-mint64 \-mips1 -\&\-mips2 \-mips3 \-mips4 \-mlong64 \-mlong32 \-mlong-calls \-mmemcpy -\&\-mmips-as \-mmips-tfile \-mno-abicalls -\&\-mno-embedded-data \-mno-uninit-const-in-rodata -\&\-mno-embedded-pic \-mno-gpopt \-mno-long-calls -\&\-mno-memcpy \-mno-mips-tfile \-mno-rnames \-mno-stats -\&\-mrnames \-msoft-float -\&\-m4650 \-msingle-float \-mmad -\&\-mstats \-EL \-EB \-G\fR \fInum\fR \fB\-nocpp -\&\-mabi=32 \-mabi=n32 \-mabi=64 \-mabi=eabi -\&\-mfix7000 \-mno-crt0 \-mflush-func=\fR\fIfunc\fR \fB\-mno-flush-func\fR +\&\fB\-EL \-EB \-march=\fR\fIarch\fR \fB\-mtune=\fR\fIarch\fR +\&\fB\-mips1 \-mips2 \-mips3 \-mips4 \-mips32 \-mips32r2 \-mips64 +\&\-mips16 \-mno\-mips16 \-mabi=\fR\fIabi\fR \fB\-mabicalls \-mno\-abicalls +\&\-mxgot \-mno\-xgot \-membedded\-pic \-mno\-embedded\-pic +\&\-mgp32 \-mgp64 \-mfp32 \-mfp64 \-mhard\-float \-msoft\-float +\&\-msingle\-float \-mdouble\-float \-mint64 \-mlong64 \-mlong32 +\&\-G\fR\fInum\fR \fB\-membedded\-data \-mno\-embedded\-data +\&\-muninit\-const\-in\-rodata \-mno\-uninit\-const\-in\-rodata +\&\-msplit\-addresses \-mno\-split\-addresses +\&\-mexplicit\-relocs \-mno\-explicit\-relocs +\&\-mrnames \-mno\-rnames +\&\-mcheck\-zero\-division \-mno\-check\-zero\-division +\&\-mmemcpy \-mno\-memcpy \-mlong\-calls \-mno\-long\-calls +\&\-mmad \-mno\-mad \-mfused\-madd \-mno\-fused\-madd \-nocpp +\&\-mfix\-sb1 \-mno\-fix\-sb1 \-mflush\-func=\fR\fIfunc\fR +\&\fB\-mno\-flush\-func \-mbranch\-likely \-mno\-branch\-likely\fR .Sp \&\fIi386 and x86\-64 Options\fR -.Sp -\&\fB\-mcpu=\fR\fIcpu-type\fR \fB\-march=\fR\fIcpu-type\fR \fB\-mfpmath=\fR\fIunit\fR -\&\fB\-masm=\fR\fIdialect\fR \fB\-mno-fancy-math-387 -\&\-mno-fp-ret-in-387 \-msoft-float \-msvr3\-shlib -\&\-mno-wide-multiply \-mrtd \-malign-double -\&\-mpreferred-stack-boundary=\fR\fInum\fR -\&\fB\-mmmx \-msse \-msse2 \-m3dnow -\&\-mthreads \-mno-align-stringops \-minline-all-stringops -\&\-mpush-args \-maccumulate-outgoing-args \-m128bit-long-double -\&\-m96bit-long-double \-mregparm=\fR\fInum\fR \fB\-momit-leaf-frame-pointer -\&\-mno-red-zone +\&\fB\-mtune=\fR\fIcpu-type\fR \fB\-march=\fR\fIcpu-type\fR +\&\fB\-mfpmath=\fR\fIunit\fR +\&\fB\-masm=\fR\fIdialect\fR \fB\-mno\-fancy\-math\-387 +\&\-mno\-fp\-ret\-in\-387 \-msoft\-float \-msvr3\-shlib +\&\-mno\-wide\-multiply \-mrtd \-malign\-double +\&\-mpreferred\-stack\-boundary=\fR\fInum\fR +\&\fB\-mmmx \-msse \-msse2 \-msse3 \-m3dnow +\&\-mthreads \-mno\-align\-stringops \-minline\-all\-stringops +\&\-mpush\-args \-maccumulate\-outgoing\-args \-m128bit\-long\-double +\&\-m96bit\-long\-double \-mregparm=\fR\fInum\fR \fB\-momit\-leaf\-frame\-pointer +\&\-mno\-red\-zone \-mno\-tls\-direct\-seg\-refs \&\-mcmodel=\fR\fIcode-model\fR -\&\fB\-m32 \-m64\fR +\&\fB\-m32 \-m64\fR .Sp \&\fI\s-1HPPA\s0 Options\fR -.Sp \&\fB\-march=\fR\fIarchitecture-type\fR -\&\fB\-mbig-switch \-mdisable-fpregs \-mdisable-indexing -\&\-mfast-indirect-calls \-mgas \-mjump-in-delay -\&\-mlong-load-store \-mno-big-switch \-mno-disable-fpregs -\&\-mno-disable-indexing \-mno-fast-indirect-calls \-mno-gas -\&\-mno-jump-in-delay \-mno-long-load-store -\&\-mno-portable-runtime \-mno-soft-float -\&\-mno-space-regs \-msoft-float \-mpa-risc-1\-0 -\&\-mpa-risc-1\-1 \-mpa-risc-2\-0 \-mportable-runtime -\&\-mschedule=\fR\fIcpu-type\fR \fB\-mspace-regs\fR +\&\fB\-mbig\-switch \-mdisable\-fpregs \-mdisable\-indexing +\&\-mfast\-indirect\-calls \-mgas \-mgnu\-ld \-mhp\-ld +\&\-mjump\-in\-delay \-mlinker\-opt \-mlong\-calls +\&\-mlong\-load\-store \-mno\-big\-switch \-mno\-disable\-fpregs +\&\-mno\-disable\-indexing \-mno\-fast\-indirect\-calls \-mno\-gas +\&\-mno\-jump\-in\-delay \-mno\-long\-load\-store +\&\-mno\-portable\-runtime \-mno\-soft\-float +\&\-mno\-space\-regs \-msoft\-float \-mpa\-risc\-1\-0 +\&\-mpa\-risc\-1\-1 \-mpa\-risc\-2\-0 \-mportable\-runtime +\&\-mschedule=\fR\fIcpu-type\fR \fB\-mspace\-regs \-msio \-mwsio +\&\-nolibdld \-static \-threads\fR .Sp \&\fIIntel 960 Options\fR -.Sp -\&\fB\-m\fR\fIcpu-type\fR \fB\-masm-compat \-mclean-linkage -\&\-mcode-align \-mcomplex-addr \-mleaf-procedures -\&\-mic-compat \-mic2.0\-compat \-mic3.0\-compat -\&\-mintel-asm \-mno-clean-linkage \-mno-code-align -\&\-mno-complex-addr \-mno-leaf-procedures -\&\-mno-old-align \-mno-strict-align \-mno-tail-call -\&\-mnumerics \-mold-align \-msoft-float \-mstrict-align -\&\-mtail-call\fR +\&\fB\-m\fR\fIcpu-type\fR \fB\-masm\-compat \-mclean\-linkage +\&\-mcode\-align \-mcomplex\-addr \-mleaf\-procedures +\&\-mic\-compat \-mic2.0\-compat \-mic3.0\-compat +\&\-mintel\-asm \-mno\-clean\-linkage \-mno\-code\-align +\&\-mno\-complex\-addr \-mno\-leaf\-procedures +\&\-mno\-old\-align \-mno\-strict\-align \-mno\-tail\-call +\&\-mnumerics \-mold\-align \-msoft\-float \-mstrict\-align +\&\-mtail\-call\fR .Sp \&\fI\s-1DEC\s0 Alpha Options\fR -.Sp -\&\fB\-mno-fp-regs \-msoft-float \-malpha-as \-mgas -\&\-mieee \-mieee-with-inexact \-mieee-conformant -\&\-mfp-trap-mode=\fR\fImode\fR \fB\-mfp-rounding-mode=\fR\fImode\fR -\&\fB\-mtrap-precision=\fR\fImode\fR \fB\-mbuild-constants +\&\fB\-mno\-fp\-regs \-msoft\-float \-malpha\-as \-mgas +\&\-mieee \-mieee\-with\-inexact \-mieee\-conformant +\&\-mfp\-trap\-mode=\fR\fImode\fR \fB\-mfp\-rounding\-mode=\fR\fImode\fR +\&\fB\-mtrap\-precision=\fR\fImode\fR \fB\-mbuild\-constants \&\-mcpu=\fR\fIcpu-type\fR \fB\-mtune=\fR\fIcpu-type\fR \&\fB\-mbwx \-mmax \-mfix \-mcix -\&\-mfloat-vax \-mfloat-ieee -\&\-mexplicit-relocs \-msmall-data \-mlarge-data -\&\-mmemory-latency=\fR\fItime\fR +\&\-mfloat\-vax \-mfloat\-ieee +\&\-mexplicit\-relocs \-msmall\-data \-mlarge\-data +\&\-msmall\-text \-mlarge\-text +\&\-mmemory\-latency=\fR\fItime\fR .Sp \&\fI\s-1DEC\s0 Alpha/VMS Options\fR -.Sp -\&\fB\-mvms-return-codes\fR -.Sp -\&\fIClipper Options\fR -.Sp -\&\fB\-mc300 \-mc400\fR +\&\fB\-mvms\-return\-codes\fR .Sp \&\fIH8/300 Options\fR -.Sp -\&\fB\-mrelax \-mh \-ms \-mint32 \-malign-300\fR +\&\fB\-mrelax \-mh \-ms \-mn \-mint32 \-malign\-300\fR .Sp \&\fI\s-1SH\s0 Options\fR -.Sp -\&\fB\-m1 \-m2 \-m3 \-m3e -\&\-m4\-nofpu \-m4\-single-only \-m4\-single \-m4 -\&\-m5\-64media \-m5\-64media-nofpu -\&\-m5\-32media \-m5\-32media-nofpu -\&\-m5\-compact \-m5\-compact-nofpu +\&\fB\-m1 \-m2 \-m2e \-m3 \-m3e +\&\-m4\-nofpu \-m4\-single\-only \-m4\-single \-m4 +\&\-m5\-64media \-m5\-64media\-nofpu +\&\-m5\-32media \-m5\-32media\-nofpu +\&\-m5\-compact \-m5\-compact\-nofpu \&\-mb \-ml \-mdalign \-mrelax \&\-mbigtable \-mfmovd \-mhitachi \-mnomacsave \&\-mieee \-misize \-mpadstruct \-mspace \&\-mprefergot \-musermode\fR .Sp \&\fISystem V Options\fR -.Sp \&\fB\-Qy \-Qn \-YP,\fR\fIpaths\fR \fB\-Ym,\fR\fIdir\fR .Sp \&\fI\s-1ARC\s0 Options\fR -.Sp \&\fB\-EB \-EL -\&\-mmangle-cpu \-mcpu=\fR\fIcpu\fR \fB\-mtext=\fR\fItext-section\fR +\&\-mmangle\-cpu \-mcpu=\fR\fIcpu\fR \fB\-mtext=\fR\fItext-section\fR \&\fB\-mdata=\fR\fIdata-section\fR \fB\-mrodata=\fR\fIreadonly-data-section\fR .Sp \&\fITMS320C3x/C4x Options\fR -.Sp \&\fB\-mcpu=\fR\fIcpu\fR \fB\-mbig \-msmall \-mregparm \-mmemparm -\&\-mfast-fix \-mmpyi \-mbk \-mti \-mdp-isr-reload -\&\-mrpts=\fR\fIcount\fR \fB\-mrptb \-mdb \-mloop-unsigned -\&\-mparallel-insns \-mparallel-mpy \-mpreserve-float\fR +\&\-mfast\-fix \-mmpyi \-mbk \-mti \-mdp\-isr\-reload +\&\-mrpts=\fR\fIcount\fR \fB\-mrptb \-mdb \-mloop\-unsigned +\&\-mparallel\-insns \-mparallel\-mpy \-mpreserve\-float\fR .Sp \&\fIV850 Options\fR -.Sp -\&\fB\-mlong-calls \-mno-long-calls \-mep \-mno-ep -\&\-mprolog-function \-mno-prolog-function \-mspace +\&\fB\-mlong\-calls \-mno\-long\-calls \-mep \-mno\-ep +\&\-mprolog\-function \-mno\-prolog\-function \-mspace \&\-mtda=\fR\fIn\fR \fB\-msda=\fR\fIn\fR \fB\-mzda=\fR\fIn\fR -\&\fB\-mv850 \-mbig-switch\fR +\&\fB\-mapp\-regs \-mno\-app\-regs +\&\-mdisable\-callt \-mno\-disable\-callt +\&\-mv850e1 +\&\-mv850e +\&\-mv850 \-mbig\-switch\fR .Sp \&\fI\s-1NS32K\s0 Options\fR -.Sp \&\fB\-m32032 \-m32332 \-m32532 \-m32081 \-m32381 -\&\-mmult-add \-mnomult-add \-msoft-float \-mrtd \-mnortd +\&\-mmult\-add \-mnomult\-add \-msoft\-float \-mrtd \-mnortd \&\-mregparam \-mnoregparam \-msb \-mnosb \&\-mbitfield \-mnobitfield \-mhimem \-mnohimem\fR .Sp \&\fI\s-1AVR\s0 Options\fR -.Sp -\&\fB\-mmcu=\fR\fImcu\fR \fB\-msize \-minit-stack=\fR\fIn\fR \fB\-mno-interrupts -\&\-mcall-prologues \-mno-tablejump \-mtiny-stack\fR +\&\fB\-mmcu=\fR\fImcu\fR \fB\-msize \-minit\-stack=\fR\fIn\fR \fB\-mno\-interrupts +\&\-mcall\-prologues \-mno\-tablejump \-mtiny\-stack\fR .Sp \&\fIMCore Options\fR -.Sp -\&\fB\-mhardlit \-mno-hardlit \-mdiv \-mno-div \-mrelax-immediates -\&\-mno-relax-immediates \-mwide-bitfields \-mno-wide-bitfields -\&\-m4byte-functions \-mno-4byte-functions \-mcallgraph-data -\&\-mno-callgraph-data \-mslow-bytes \-mno-slow-bytes \-mno-lsim -\&\-mlittle-endian \-mbig-endian \-m210 \-m340 \-mstack-increment\fR +\&\fB\-mhardlit \-mno\-hardlit \-mdiv \-mno\-div \-mrelax\-immediates +\&\-mno\-relax\-immediates \-mwide\-bitfields \-mno\-wide\-bitfields +\&\-m4byte\-functions \-mno\-4byte\-functions \-mcallgraph\-data +\&\-mno\-callgraph\-data \-mslow\-bytes \-mno\-slow\-bytes \-mno\-lsim +\&\-mlittle\-endian \-mbig\-endian \-m210 \-m340 \-mstack\-increment\fR .Sp \&\fI\s-1MMIX\s0 Options\fR -.Sp -\&\fB\-mlibfuncs \-mno-libfuncs \-mepsilon \-mno-epsilon \-mabi=gnu -\&\-mabi=mmixware \-mzero-extend \-mknuthdiv \-mtoplevel-symbols -\&\-melf \-mbranch-predict \-mno-branch-predict \-mbase-addresses -\&\-mno-base-addresses\fR -.Sp -\&\fI\s-1IA-64\s0 Options\fR -.Sp -\&\fB\-mbig-endian \-mlittle-endian \-mgnu-as \-mgnu-ld \-mno-pic -\&\-mvolatile-asm-stop \-mb-step \-mregister-names \-mno-sdata -\&\-mconstant-gp \-mauto-pic \-minline-divide-min-latency -\&\-minline-divide-max-throughput \-mno-dwarf2\-asm -\&\-mfixed-range=\fR\fIregister-range\fR +\&\fB\-mlibfuncs \-mno\-libfuncs \-mepsilon \-mno\-epsilon \-mabi=gnu +\&\-mabi=mmixware \-mzero\-extend \-mknuthdiv \-mtoplevel\-symbols +\&\-melf \-mbranch\-predict \-mno\-branch\-predict \-mbase\-addresses +\&\-mno\-base\-addresses \-msingle\-exit \-mno\-single\-exit\fR +.Sp +\&\fI\s-1IA\-64\s0 Options\fR +\&\fB\-mbig\-endian \-mlittle\-endian \-mgnu\-as \-mgnu\-ld \-mno\-pic +\&\-mvolatile\-asm\-stop \-mb\-step \-mregister\-names \-mno\-sdata +\&\-mconstant\-gp \-mauto\-pic \-minline\-float\-divide\-min\-latency +\&\-minline\-float\-divide\-max\-throughput +\&\-minline\-int\-divide\-min\-latency +\&\-minline\-int\-divide\-max\-throughput +\&\-minline\-sqrt\-min\-latency \-minline\-sqrt\-max\-throughput +\&\-mno\-dwarf2\-asm \-mearly\-stop\-bits +\&\-mfixed\-range=\fR\fIregister-range\fR \fB\-mtls\-size=\fR\fItls-size\fR +\&\fB\-mtune=\fR\fIcpu-type\fR \fB\-mt \-pthread \-milp32 \-mlp64\fR .Sp \&\fID30V Options\fR -.Sp -\&\fB\-mextmem \-mextmemory \-monchip \-mno-asm-optimize -\&\-masm-optimize \-mbranch-cost=\fR\fIn\fR \fB\-mcond-exec=\fR\fIn\fR +\&\fB\-mextmem \-mextmemory \-monchip \-mno\-asm\-optimize +\&\-masm\-optimize \-mbranch\-cost=\fR\fIn\fR \fB\-mcond\-exec=\fR\fIn\fR .Sp \&\fIS/390 and zSeries Options\fR -.Sp -\&\fB\-mhard-float \-msoft-float \-mbackchain \-mno-backchain -\&\-msmall-exec \-mno-small-exec \-mmvcle \-mno-mvcle -\&\-m64 \-m31 \-mdebug \-mno-debug\fR +\&\fB\-mtune=\fR\fIcpu-type\fR \fB\-march=\fR\fIcpu-type\fR +\&\fB\-mhard\-float \-msoft\-float \-mbackchain \-mno\-backchain +\&\-msmall\-exec \-mno\-small\-exec \-mmvcle \-mno\-mvcle +\&\-m64 \-m31 \-mdebug \-mno\-debug \-mesa \-mzarch \-mfused\-madd \-mno\-fused\-madd\fR .Sp \&\fI\s-1CRIS\s0 Options\fR -.Sp -\&\fB\-mcpu=\fR\fIcpu\fR \fB\-march=\fR\fIcpu\fR \fB\-mtune=\fR\fIcpu\fR -\&\fB\-mmax-stack-frame=\fR\fIn\fR \fB\-melinux-stacksize=\fR\fIn\fR -\&\fB\-metrax4 \-metrax100 \-mpdebug \-mcc-init \-mno-side-effects -\&\-mstack-align \-mdata-align \-mconst-align -\&\-m32\-bit \-m16\-bit \-m8\-bit \-mno-prologue-epilogue \-mno-gotplt -\&\-melf \-maout \-melinux \-mlinux \-sim \-sim2\fR -.Sp -\&\fI\s-1PDP-11\s0 Options\fR -.Sp -\&\fB\-mfpu \-msoft-float \-mac0 \-mno-ac0 \-m40 \-m45 \-m10 -\&\-mbcopy \-mbcopy-builtin \-mint32 \-mno-int16 -\&\-mint16 \-mno-int32 \-mfloat32 \-mno-float64 -\&\-mfloat64 \-mno-float32 \-mabshi \-mno-abshi -\&\-mbranch-expensive \-mbranch-cheap -\&\-msplit \-mno-split \-munix-asm \-mdec-asm\fR +\&\fB\-mcpu=\fR\fIcpu\fR \fB\-march=\fR\fIcpu\fR \fB\-mtune=\fR\fIcpu\fR +\&\fB\-mmax\-stack\-frame=\fR\fIn\fR \fB\-melinux\-stacksize=\fR\fIn\fR +\&\fB\-metrax4 \-metrax100 \-mpdebug \-mcc\-init \-mno\-side\-effects +\&\-mstack\-align \-mdata\-align \-mconst\-align +\&\-m32\-bit \-m16\-bit \-m8\-bit \-mno\-prologue\-epilogue \-mno\-gotplt +\&\-melf \-maout \-melinux \-mlinux \-sim \-sim2 +\&\-mmul\-bug\-workaround \-mno\-mul\-bug\-workaround\fR +.Sp +\&\fI\s-1PDP\-11\s0 Options\fR +\&\fB\-mfpu \-msoft\-float \-mac0 \-mno\-ac0 \-m40 \-m45 \-m10 +\&\-mbcopy \-mbcopy\-builtin \-mint32 \-mno\-int16 +\&\-mint16 \-mno\-int32 \-mfloat32 \-mno\-float64 +\&\-mfloat64 \-mno\-float32 \-mabshi \-mno\-abshi +\&\-mbranch\-expensive \-mbranch\-cheap +\&\-msplit \-mno\-split \-munix\-asm \-mdec\-asm\fR .Sp \&\fIXstormy16 Options\fR -.Sp \&\fB\-msim\fR .Sp \&\fIXtensa Options\fR -.Sp -\&\fB\-mbig-endian \-mlittle-endian -\&\-mdensity \-mno-density -\&\-mmac16 \-mno-mac16 -\&\-mmul16 \-mno-mul16 -\&\-mmul32 \-mno-mul32 -\&\-mnsa \-mno-nsa -\&\-mminmax \-mno-minmax -\&\-msext \-mno-sext -\&\-mbooleans \-mno-booleans -\&\-mhard-float \-msoft-float -\&\-mfused-madd \-mno-fused-madd -\&\-mserialize-volatile \-mno-serialize-volatile -\&\-mtext-section-literals \-mno-text-section-literals -\&\-mtarget-align \-mno-target-align -\&\-mlongcalls \-mno-longcalls\fR -.Ip "\fICode Generation Options\fR" 4 +\&\fB\-mconst16 \-mno\-const16 +\&\-mfused\-madd \-mno\-fused\-madd +\&\-mtext\-section\-literals \-mno\-text\-section\-literals +\&\-mtarget\-align \-mno\-target\-align +\&\-mlongcalls \-mno\-longcalls\fR +.Sp +\&\fI\s-1FRV\s0 Options\fR +\&\fB\-mgpr\-32 \-mgpr\-64 \-mfpr\-32 \-mfpr\-64 +\&\-mhard\-float \-msoft\-float +\&\-malloc\-cc \-mfixed\-cc \-mdword \-mno\-dword +\&\-mdouble \-mno\-double +\&\-mmedia \-mno\-media \-mmuladd \-mno\-muladd +\&\-mlibrary\-pic \-macc\-4 \-macc\-8 +\&\-mpack \-mno\-pack \-mno\-eflags \-mcond\-move \-mno\-cond\-move +\&\-mscc \-mno\-scc \-mcond\-exec \-mno\-cond\-exec +\&\-mvliw\-branch \-mno\-vliw\-branch +\&\-mmulti\-cond\-exec \-mno\-multi\-cond\-exec \-mnested\-cond\-exec +\&\-mno\-nested\-cond\-exec \-mtomcat\-stats +\&\-mcpu=\fR\fIcpu\fR +.IP "\fICode Generation Options\fR" 4 .IX Item "Code Generation Options" -\&\fB\-fcall-saved-\fR\fIreg\fR \fB\-fcall-used-\fR\fIreg\fR -\&\fB\-ffixed-\fR\fIreg\fR \fB\-fexceptions -\&\-fnon-call-exceptions \-funwind-tables -\&\-fasynchronous-unwind-tables -\&\-finhibit-size-directive \-finstrument-functions -\&\-fno-common \-fno-ident \-fno-gnu-linker -\&\-fpcc-struct-return \-fpic \-fPIC -\&\-freg-struct-return \-fshared-data \-fshort-enums -\&\-fshort-double \-fshort-wchar \-fvolatile -\&\-fvolatile-global \-fvolatile-static -\&\-fverbose-asm \-fpack-struct \-fstack-check -\&\-fstack-limit-register=\fR\fIreg\fR \fB\-fstack-limit-symbol=\fR\fIsym\fR -\&\fB\-fargument-alias \-fargument-noalias -\&\-fargument-noalias-global \-fleading-underscore\fR +\&\fB\-fcall\-saved\-\fR\fIreg\fR \fB\-fcall\-used\-\fR\fIreg\fR +\&\fB\-ffixed\-\fR\fIreg\fR \fB\-fexceptions +\&\-fnon\-call\-exceptions \-funwind\-tables +\&\-fasynchronous\-unwind\-tables +\&\-finhibit\-size\-directive \-finstrument\-functions +\&\-fno\-common \-fno\-ident +\&\-fpcc\-struct\-return \-fpic \-fPIC \-fpie \-fPIE +\&\-freg\-struct\-return \-fshared\-data \-fshort\-enums +\&\-fshort\-double \-fshort\-wchar +\&\-fverbose\-asm \-fpack\-struct \-fstack\-check +\&\-fstack\-limit\-register=\fR\fIreg\fR \fB\-fstack\-limit\-symbol=\fR\fIsym\fR +\&\fB\-fargument\-alias \-fargument\-noalias +\&\-fargument\-noalias\-global \-fleading\-underscore +\&\-ftls\-model=\fR\fImodel\fR +\&\fB\-ftrapv \-fwrapv \-fbounds\-check\fR .Sh "Options Controlling the Kind of Output" .IX Subsection "Options Controlling the Kind of Output" Compilation can involve up to four stages: preprocessing, compilation -proper, assembly and linking, always in that order. The first three -stages apply to an individual source file, and end by producing an -object file; linking combines all the object files (those newly -compiled, and those specified as input) into an executable file. +proper, assembly and linking, always in that order. \s-1GCC\s0 is capable of +preprocessing and compiling several files either into several +assembler input files, or into one assembler input file; then each +assembler input file produces an object file, and linking combines all +the object files (those newly compiled, and those specified as input) +into an executable file. .PP For any given input file, the file name suffix determines what kind of compilation is done: -.Ip "\fIfile\fR\fB.c\fR" 4 +.IP "\fIfile\fR\fB.c\fR" 4 .IX Item "file.c" C source code which must be preprocessed. -.Ip "\fIfile\fR\fB.i\fR" 4 +.IP "\fIfile\fR\fB.i\fR" 4 .IX Item "file.i" C source code which should not be preprocessed. -.Ip "\fIfile\fR\fB.ii\fR" 4 +.IP "\fIfile\fR\fB.ii\fR" 4 .IX Item "file.ii" \&\*(C+ source code which should not be preprocessed. -.Ip "\fIfile\fR\fB.m\fR" 4 +.IP "\fIfile\fR\fB.m\fR" 4 .IX Item "file.m" Objective-C source code. Note that you must link with the library \&\fIlibobjc.a\fR to make an Objective-C program work. -.Ip "\fIfile\fR\fB.mi\fR" 4 +.IP "\fIfile\fR\fB.mi\fR" 4 .IX Item "file.mi" Objective-C source code which should not be preprocessed. -.Ip "\fIfile\fR\fB.h\fR" 4 +.IP "\fIfile\fR\fB.h\fR" 4 .IX Item "file.h" -C header file (not to be compiled or linked). -.Ip "\fIfile\fR\fB.cc\fR" 4 +C or \*(C+ header file to be turned into a precompiled header. +.IP "\fIfile\fR\fB.cc\fR" 4 .IX Item "file.cc" .PD 0 -.Ip "\fIfile\fR\fB.cp\fR" 4 +.IP "\fIfile\fR\fB.cp\fR" 4 .IX Item "file.cp" -.Ip "\fIfile\fR\fB.cxx\fR" 4 +.IP "\fIfile\fR\fB.cxx\fR" 4 .IX Item "file.cxx" -.Ip "\fIfile\fR\fB.cpp\fR" 4 +.IP "\fIfile\fR\fB.cpp\fR" 4 .IX Item "file.cpp" -.Ip "\fIfile\fR\fB.c++\fR" 4 +.IP "\fIfile\fR\fB.CPP\fR" 4 +.IX Item "file.CPP" +.IP "\fIfile\fR\fB.c++\fR" 4 .IX Item "file.c++" -.Ip "\fIfile\fR\fB.C\fR" 4 +.IP "\fIfile\fR\fB.C\fR" 4 .IX Item "file.C" .PD \&\*(C+ source code which must be preprocessed. Note that in \fB.cxx\fR, the last two letters must both be literally \fBx\fR. Likewise, \&\fB.C\fR refers to a literal capital C. -.Ip "\fIfile\fR\fB.f\fR" 4 +.IP "\fIfile\fR\fB.hh\fR" 4 +.IX Item "file.hh" +.PD 0 +.IP "\fIfile\fR\fB.H\fR" 4 +.IX Item "file.H" +.PD +\&\*(C+ header file to be turned into a precompiled header. +.IP "\fIfile\fR\fB.f\fR" 4 .IX Item "file.f" .PD 0 -.Ip "\fIfile\fR\fB.for\fR" 4 +.IP "\fIfile\fR\fB.for\fR" 4 .IX Item "file.for" -.Ip "\fIfile\fR\fB.FOR\fR" 4 +.IP "\fIfile\fR\fB.FOR\fR" 4 .IX Item "file.FOR" .PD Fortran source code which should not be preprocessed. -.Ip "\fIfile\fR\fB.F\fR" 4 +.IP "\fIfile\fR\fB.F\fR" 4 .IX Item "file.F" .PD 0 -.Ip "\fIfile\fR\fB.fpp\fR" 4 +.IP "\fIfile\fR\fB.fpp\fR" 4 .IX Item "file.fpp" -.Ip "\fIfile\fR\fB.FPP\fR" 4 +.IP "\fIfile\fR\fB.FPP\fR" 4 .IX Item "file.FPP" .PD Fortran source code which must be preprocessed (with the traditional preprocessor). -.Ip "\fIfile\fR\fB.r\fR" 4 +.IP "\fIfile\fR\fB.r\fR" 4 .IX Item "file.r" Fortran source code which must be preprocessed with a \s-1RATFOR\s0 preprocessor (not included with \s-1GCC\s0). -.Ip "\fIfile\fR\fB.ads\fR" 4 +.IP "\fIfile\fR\fB.ads\fR" 4 .IX Item "file.ads" Ada source code file which contains a library unit declaration (a declaration of a package, subprogram, or generic, or a generic instantiation), or a library unit renaming declaration (a package, generic, or subprogram renaming declaration). Such files are also called \fIspecs\fR. -.Ip "\fIfile\fR\fB.adb\fR" 4 +.IP "\fIfile\fR\fB.adb\fR" 4 .IX Item "file.adb" Ada source code file containing a library unit body (a subprogram or package body). Such files are also called \fIbodies\fR. -.Ip "\fIfile\fR\fB.s\fR" 4 +.IP "\fIfile\fR\fB.s\fR" 4 .IX Item "file.s" Assembler code. -.Ip "\fIfile\fR\fB.S\fR" 4 +.IP "\fIfile\fR\fB.S\fR" 4 .IX Item "file.S" Assembler code which must be preprocessed. -.Ip "\fIother\fR" 4 +.IP "\fIother\fR" 4 .IX Item "other" An object file to be fed straight into linking. Any file name with no recognized suffix is treated this way. .PP You can specify the input language explicitly with the \fB\-x\fR option: -.Ip "\fB\-x\fR \fIlanguage\fR" 4 +.IP "\fB\-x\fR \fIlanguage\fR" 4 .IX Item "-x language" Specify explicitly the \fIlanguage\fR for the following input files (rather than letting the compiler choose a default based on the file name suffix). This option applies to all following input files until the next \fB\-x\fR option. Possible values for \fIlanguage\fR are: .Sp -.Vb 7 +.Vb 8 \& c c-header cpp-output -\& c++ c++-cpp-output -\& objective-c objc-cpp-output +\& c++ c++-header c++-cpp-output +\& objective-c objective-c-header objc-cpp-output \& assembler assembler-with-cpp \& ada \& f77 f77-cpp-input ratfor \& java +\& treelang .Ve -.Ip "\fB\-x none\fR" 4 +.IP "\fB\-x none\fR" 4 .IX Item "-x none" Turn off any specification of a language, so that subsequent files are handled according to their file name suffixes (as they are if \fB\-x\fR has not been used at all). -.Ip "\fB\-pass-exit-codes\fR" 4 +.IP "\fB\-pass\-exit\-codes\fR" 4 .IX Item "-pass-exit-codes" Normally the \fBgcc\fR program will exit with the code of 1 if any phase of the compiler returns a non-success return code. If you specify -\&\fB\-pass-exit-codes\fR, the \fBgcc\fR program will instead return with +\&\fB\-pass\-exit\-codes\fR, the \fBgcc\fR program will instead return with numerically highest error produced by any phase that returned an error indication. .PP @@ -819,7 +831,7 @@ If you only want some of the stages of compilation, you can use one of the options \fB\-c\fR, \fB\-S\fR, or \fB\-E\fR to say where \&\fBgcc\fR is to stop. Note that some combinations (for example, \&\fB\-x cpp-output \-E\fR) instruct \fBgcc\fR to do nothing at all. -.Ip "\fB\-c\fR" 4 +.IP "\fB\-c\fR" 4 .IX Item "-c" Compile or assemble the source files, but do not link. The linking stage simply is not done. The ultimate output is in the form of an @@ -830,7 +842,7 @@ the suffix \fB.c\fR, \fB.i\fR, \fB.s\fR, etc., with \fB.o\fR. .Sp Unrecognized input files, not requiring compilation or assembly, are ignored. -.Ip "\fB\-S\fR" 4 +.IP "\fB\-S\fR" 4 .IX Item "-S" Stop after the stage of compilation proper; do not assemble. The output is in the form of an assembler code file for each non-assembler input @@ -840,76 +852,78 @@ By default, the assembler file name for a source file is made by replacing the suffix \fB.c\fR, \fB.i\fR, etc., with \fB.s\fR. .Sp Input files that don't require compilation are ignored. -.Ip "\fB\-E\fR" 4 +.IP "\fB\-E\fR" 4 .IX Item "-E" Stop after the preprocessing stage; do not run the compiler proper. The output is in the form of preprocessed source code, which is sent to the standard output. .Sp Input files which don't require preprocessing are ignored. -.Ip "\fB\-o\fR \fIfile\fR" 4 +.IP "\fB\-o\fR \fIfile\fR" 4 .IX Item "-o file" Place output in file \fIfile\fR. This applies regardless to whatever sort of output is being produced, whether it be an executable file, an object file, an assembler file or preprocessed C code. .Sp -Since only one output file can be specified, it does not make sense to -use \fB\-o\fR when compiling more than one input file, unless you are -producing an executable file as output. +If you specify \fB\-o\fR when compiling more than one input file, or +you are producing an executable file as output, all the source files +on the command line will be compiled at once. .Sp If \fB\-o\fR is not specified, the default is to put an executable file in \fIa.out\fR, the object file for \fI\fIsource\fI.\fIsuffix\fI\fR in \&\fI\fIsource\fI.o\fR, its assembler file in \fI\fIsource\fI.s\fR, and all preprocessed C source on standard output. -.Ip "\fB\-v\fR" 4 +.IP "\fB\-v\fR" 4 .IX Item "-v" Print (on standard error output) the commands executed to run the stages of compilation. Also print the version number of the compiler driver program and of the preprocessor and the compiler proper. -.Ip "\fB\-###\fR" 4 +.IP "\fB\-###\fR" 4 .IX Item "-###" Like \fB\-v\fR except the commands are not executed and all command arguments are quoted. This is useful for shell scripts to capture the driver-generated command lines. -.Ip "\fB\-pipe\fR" 4 +.IP "\fB\-pipe\fR" 4 .IX Item "-pipe" Use pipes rather than temporary files for communication between the various stages of compilation. This fails to work on some systems where the assembler is unable to read from a pipe; but the \s-1GNU\s0 assembler has no trouble. -.Ip "\fB\*(--help\fR" 4 -.IX Item "help" +.IP "\fB\-\-help\fR" 4 +.IX Item "--help" Print (on the standard output) a description of the command line options understood by \fBgcc\fR. If the \fB\-v\fR option is also specified -then \fB\*(--help\fR will also be passed on to the various processes +then \fB\-\-help\fR will also be passed on to the various processes invoked by \fBgcc\fR, so that they can display the command line options -they accept. If the \fB\-W\fR option is also specified then command +they accept. If the \fB\-Wextra\fR option is also specified then command line options which have no documentation associated with them will also be displayed. -.Ip "\fB\*(--target-help\fR" 4 -.IX Item "target-help" +.IP "\fB\-\-target\-help\fR" 4 +.IX Item "--target-help" Print (on the standard output) a description of target specific command line options for each tool. -.Ip "\fB\*(--version\fR" 4 -.IX Item "version" +.IP "\fB\-\-version\fR" 4 +.IX Item "--version" Display the version number and copyrights of the invoked \s-1GCC\s0. .Sh "Compiling \*(C+ Programs" .IX Subsection "Compiling Programs" \&\*(C+ source files conventionally use one of the suffixes \fB.C\fR, -\&\fB.cc\fR, \fB.cpp\fR, \fB.c++\fR, \fB.cp\fR, or \fB.cxx\fR; +\&\fB.cc\fR, \fB.cpp\fR, \fB.CPP\fR, \fB.c++\fR, \fB.cp\fR, or +\&\fB.cxx\fR; \*(C+ header files often use \fB.hh\fR or \fB.H\fR; and preprocessed \*(C+ files use the suffix \fB.ii\fR. \s-1GCC\s0 recognizes files with these names and compiles them as \*(C+ programs even if you -call the compiler the same way as for compiling C programs (usually with -the name \fBgcc\fR). +call the compiler the same way as for compiling C programs (usually +with the name \fBgcc\fR). .PP However, \*(C+ programs often require class libraries as well as a compiler that understands the \*(C+ language\-\-\-and under some -circumstances, you might want to compile programs from standard input, -or otherwise without a suffix that flags them as \*(C+ programs. -\&\fBg++\fR is a program that calls \s-1GCC\s0 with the default language -set to \*(C+, and automatically specifies linking against the \*(C+ -library. On many systems, \fBg++\fR is also -installed with the name \fBc++\fR. +circumstances, you might want to compile programs or header files from +standard input, or otherwise without a suffix that flags them as \*(C+ +programs. You might also like to precompile a C header file with a +\&\fB.h\fR extension to be used in \*(C+ compilations. \fBg++\fR is a +program that calls \s-1GCC\s0 with the default language set to \*(C+, and +automatically specifies linking against the \*(C+ library. On many +systems, \fBg++\fR is also installed with the name \fBc++\fR. .PP When you compile \*(C+ programs, you may specify many of the same command-line options that you use for compiling programs in any @@ -918,14 +932,14 @@ languages; or options that are meaningful only for \*(C+ programs. .Sh "Options Controlling C Dialect" .IX Subsection "Options Controlling C Dialect" The following options control the dialect of C (or languages derived -from C, such as \*(C+ and Objective-C) that the compiler accepts: -.Ip "\fB\-ansi\fR" 4 +from C, such as \*(C+ and Objective\-C) that the compiler accepts: +.IP "\fB\-ansi\fR" 4 .IX Item "-ansi" -In C mode, support all \s-1ISO\s0 C89 programs. In \*(C+ mode, +In C mode, support all \s-1ISO\s0 C90 programs. In \*(C+ mode, remove \s-1GNU\s0 extensions that conflict with \s-1ISO\s0 \*(C+. .Sp This turns off certain features of \s-1GCC\s0 that are incompatible with \s-1ISO\s0 -C89 (when compiling C code), or of standard \*(C+ (when compiling \*(C+ code), +C90 (when compiling C code), or of standard \*(C+ (when compiling \*(C+ code), such as the \f(CW\*(C`asm\*(C'\fR and \f(CW\*(C`typeof\*(C'\fR keywords, and predefined macros such as \f(CW\*(C`unix\*(C'\fR and \f(CW\*(C`vax\*(C'\fR that identify the type of system you are using. It also enables the undesirable and @@ -954,46 +968,53 @@ programs that might use these names for other things. Functions which would normally be built in but do not have semantics defined by \s-1ISO\s0 C (such as \f(CW\*(C`alloca\*(C'\fR and \f(CW\*(C`ffs\*(C'\fR) are not built-in functions with \fB\-ansi\fR is used. -.Ip "\fB\-std=\fR" 4 +.IP "\fB\-std=\fR" 4 .IX Item "-std=" Determine the language standard. This option is currently only -supported when compiling C. A value for this option must be provided; -possible values are +supported when compiling C or \*(C+. A value for this option must be +provided; possible values are .RS 4 -.Ip "\fBc89\fR" 4 +.IP "\fBc89\fR" 4 .IX Item "c89" .PD 0 -.Ip "\fBiso9899:1990\fR" 4 +.IP "\fBiso9899:1990\fR" 4 .IX Item "iso9899:1990" .PD -\&\s-1ISO\s0 C89 (same as \fB\-ansi\fR). -.Ip "\fBiso9899:199409\fR" 4 +\&\s-1ISO\s0 C90 (same as \fB\-ansi\fR). +.IP "\fBiso9899:199409\fR" 4 .IX Item "iso9899:199409" -\&\s-1ISO\s0 C89 as modified in amendment 1. -.Ip "\fBc99\fR" 4 +\&\s-1ISO\s0 C90 as modified in amendment 1. +.IP "\fBc99\fR" 4 .IX Item "c99" .PD 0 -.Ip "\fBc9x\fR" 4 +.IP "\fBc9x\fR" 4 .IX Item "c9x" -.Ip "\fBiso9899:1999\fR" 4 +.IP "\fBiso9899:1999\fR" 4 .IX Item "iso9899:1999" -.Ip "\fBiso9899:199x\fR" 4 +.IP "\fBiso9899:199x\fR" 4 .IX Item "iso9899:199x" .PD \&\s-1ISO\s0 C99. Note that this standard is not yet fully supported; see -<\fBhttp://gcc.gnu.org/gcc-3.1/c99status.html\fR> for more information. The +<\fBhttp://gcc.gnu.org/gcc\-3.4/c99status.html\fR> for more information. The names \fBc9x\fR and \fBiso9899:199x\fR are deprecated. -.Ip "\fBgnu89\fR" 4 +.IP "\fBgnu89\fR" 4 .IX Item "gnu89" -Default, \s-1ISO\s0 C89 plus \s-1GNU\s0 extensions (including some C99 features). -.Ip "\fBgnu99\fR" 4 +Default, \s-1ISO\s0 C90 plus \s-1GNU\s0 extensions (including some C99 features). +.IP "\fBgnu99\fR" 4 .IX Item "gnu99" .PD 0 -.Ip "\fBgnu9x\fR" 4 +.IP "\fBgnu9x\fR" 4 .IX Item "gnu9x" .PD \&\s-1ISO\s0 C99 plus \s-1GNU\s0 extensions. When \s-1ISO\s0 C99 is fully implemented in \s-1GCC\s0, this will become the default. The name \fBgnu9x\fR is deprecated. +.IP "\fBc++98\fR" 4 +.IX Item "c++98" +The 1998 \s-1ISO\s0 \*(C+ standard plus amendments. +.IP "\fBgnu++98\fR" 4 +.IX Item "gnu++98" +The same as \fB\-std=c++98\fR plus \s-1GNU\s0 extensions. This is the +default for \*(C+ code. .RE .RS 4 .Sp @@ -1003,11 +1024,11 @@ previous C standards. For example, you may use \f(CW\*(C`_\|_restrict_\|_\*(C'\ when \fB\-std=c99\fR is not specified. .Sp The \fB\-std\fR options specifying some version of \s-1ISO\s0 C have the same -effects as \fB\-ansi\fR, except that features that were not in \s-1ISO\s0 C89 +effects as \fB\-ansi\fR, except that features that were not in \s-1ISO\s0 C90 but are in the specified version (for example, \fB//\fR comments and the \f(CW\*(C`inline\*(C'\fR keyword in \s-1ISO\s0 C99) are not disabled. .RE -.Ip "\fB\-aux-info\fR \fIfilename\fR" 4 +.IP "\fB\-aux\-info\fR \fIfilename\fR" 4 .IX Item "-aux-info filename" Output to the given filename prototyped declarations for all functions declared and/or defined in a translation unit, including those in header @@ -1019,27 +1040,27 @@ implicit, prototyped or unprototyped (\fBI\fR, \fBN\fR for new or \&\fBO\fR for old, respectively, in the first character after the line number and the colon), and whether it came from a declaration or a definition (\fBC\fR or \fBF\fR, respectively, in the following -character). In the case of function definitions, a K&R-style list of +character). In the case of function definitions, a K&R\-style list of arguments followed by their declarations is also provided, inside comments, after the declaration. -.Ip "\fB\-fno-asm\fR" 4 +.IP "\fB\-fno\-asm\fR" 4 .IX Item "-fno-asm" Do not recognize \f(CW\*(C`asm\*(C'\fR, \f(CW\*(C`inline\*(C'\fR or \f(CW\*(C`typeof\*(C'\fR as a keyword, so that code can use these words as identifiers. You can use the keywords \f(CW\*(C`_\|_asm_\|_\*(C'\fR, \f(CW\*(C`_\|_inline_\|_\*(C'\fR and \f(CW\*(C`_\|_typeof_\|_\*(C'\fR -instead. \fB\-ansi\fR implies \fB\-fno-asm\fR. +instead. \fB\-ansi\fR implies \fB\-fno\-asm\fR. .Sp In \*(C+, this switch only affects the \f(CW\*(C`typeof\*(C'\fR keyword, since \&\f(CW\*(C`asm\*(C'\fR and \f(CW\*(C`inline\*(C'\fR are standard keywords. You may want to -use the \fB\-fno-gnu-keywords\fR flag instead, which has the same +use the \fB\-fno\-gnu\-keywords\fR flag instead, which has the same effect. In C99 mode (\fB\-std=c99\fR or \fB\-std=gnu99\fR), this switch only affects the \f(CW\*(C`asm\*(C'\fR and \f(CW\*(C`typeof\*(C'\fR keywords, since \&\f(CW\*(C`inline\*(C'\fR is a standard keyword in \s-1ISO\s0 C99. -.Ip "\fB\-fno-builtin\fR" 4 +.IP "\fB\-fno\-builtin\fR" 4 .IX Item "-fno-builtin" .PD 0 -.Ip "\fB\-fno-builtin-\fR\fIfunction\fR\fB \fR(C and Objective-C only)" 4 -.IX Item "-fno-builtin-function (C and Objective-C only)" +.IP "\fB\-fno\-builtin\-\fR\fIfunction\fR" 4 +.IX Item "-fno-builtin-function" .PD Don't recognize built-in functions that do not begin with \&\fB_\|_builtin_\fR as prefix. @@ -1052,117 +1073,66 @@ and faster, but since the function calls no longer appear as such, you cannot set a breakpoint on those calls, nor can you change the behavior of the functions by linking with a different library. .Sp -In \*(C+, \fB\-fno-builtin\fR is always in effect. The \fB\-fbuiltin\fR -option has no effect. Therefore, in \*(C+, the only way to get the -optimization benefits of built-in functions is to call the function -using the \fB_\|_builtin_\fR prefix. The \s-1GNU\s0 \*(C+ Standard Library uses -built-in functions to implement many functions (like -\&\f(CW\*(C`std::strchr\*(C'\fR), so that you automatically get efficient code. -.Sp -With the \fB\-fno-builtin-\fR\fIfunction\fR option, not available -when compiling \*(C+, only the built-in function \fIfunction\fR is +With the \fB\-fno\-builtin\-\fR\fIfunction\fR option +only the built-in function \fIfunction\fR is disabled. \fIfunction\fR must not begin with \fB_\|_builtin_\fR. If a function is named this is not built-in in this version of \s-1GCC\s0, this option is ignored. There is no corresponding -\&\fB\-fbuiltin-\fR\fIfunction\fR option; if you wish to enable -built-in functions selectively when using \fB\-fno-builtin\fR or +\&\fB\-fbuiltin\-\fR\fIfunction\fR option; if you wish to enable +built-in functions selectively when using \fB\-fno\-builtin\fR or \&\fB\-ffreestanding\fR, you may define macros such as: .Sp .Vb 2 \& #define abs(n) __builtin_abs ((n)) \& #define strcpy(d, s) __builtin_strcpy ((d), (s)) .Ve -.Ip "\fB\-fhosted\fR" 4 +.IP "\fB\-fhosted\fR" 4 .IX Item "-fhosted" Assert that compilation takes place in a hosted environment. This implies \&\fB\-fbuiltin\fR. A hosted environment is one in which the entire standard library is available, and in which \f(CW\*(C`main\*(C'\fR has a return type of \f(CW\*(C`int\*(C'\fR. Examples are nearly everything except a kernel. -This is equivalent to \fB\-fno-freestanding\fR. -.Ip "\fB\-ffreestanding\fR" 4 +This is equivalent to \fB\-fno\-freestanding\fR. +.IP "\fB\-ffreestanding\fR" 4 .IX Item "-ffreestanding" Assert that compilation takes place in a freestanding environment. This -implies \fB\-fno-builtin\fR. A freestanding environment +implies \fB\-fno\-builtin\fR. A freestanding environment is one in which the standard library may not exist, and program startup may not necessarily be at \f(CW\*(C`main\*(C'\fR. The most obvious example is an \s-1OS\s0 kernel. -This is equivalent to \fB\-fno-hosted\fR. -.Ip "\fB\-trigraphs\fR" 4 +This is equivalent to \fB\-fno\-hosted\fR. +.IP "\fB\-fms\-extensions\fR" 4 +.IX Item "-fms-extensions" +Accept some non-standard constructs used in Microsoft header files. +.IP "\fB\-trigraphs\fR" 4 .IX Item "-trigraphs" Support \s-1ISO\s0 C trigraphs. The \fB\-ansi\fR option (and \fB\-std\fR options for strict \s-1ISO\s0 C conformance) implies \fB\-trigraphs\fR. -.Ip "\fB\-no-integrated-cpp\fR" 4 +.IP "\fB\-no\-integrated\-cpp\fR" 4 .IX Item "-no-integrated-cpp" -Invoke the external cpp during compilation. The default is to use the -integrated cpp (internal cpp). This option also allows a -user-supplied cpp via the \fB\-B\fR option. This flag is applicable -in both C and \*(C+ modes. -.Sp -We do not guarantee to retain this option in future, and we may change -its semantics. -.Ip "\fB\-traditional\fR" 4 +Performs a compilation in two passes: preprocessing and compiling. This +option allows a user supplied \*(L"cc1\*(R", \*(L"cc1plus\*(R", or \*(L"cc1obj\*(R" via the +\&\fB\-B\fR option. The user supplied compilation step can then add in +an additional preprocessing step after normal preprocessing but before +compiling. The default is to use the integrated cpp (internal cpp) +.Sp +The semantics of this option will change if \*(L"cc1\*(R", \*(L"cc1plus\*(R", and +\&\*(L"cc1obj\*(R" are merged. +.IP "\fB\-traditional\fR" 4 .IX Item "-traditional" -Attempt to support some aspects of traditional C compilers. -Specifically: -.RS 4 -.Ip "\(bu" 4 -All \f(CW\*(C`extern\*(C'\fR declarations take effect globally even if they -are written inside of a function definition. This includes implicit -declarations of functions. -.Ip "\(bu" 4 -The newer keywords \f(CW\*(C`typeof\*(C'\fR, \f(CW\*(C`inline\*(C'\fR, \f(CW\*(C`signed\*(C'\fR, \f(CW\*(C`const\*(C'\fR -and \f(CW\*(C`volatile\*(C'\fR are not recognized. (You can still use the -alternative keywords such as \f(CW\*(C`_\|_typeof_\|_\*(C'\fR, \f(CW\*(C`_\|_inline_\|_\*(C'\fR, and -so on.) -.Ip "\(bu" 4 -Comparisons between pointers and integers are always allowed. -.Ip "\(bu" 4 -Integer types \f(CW\*(C`unsigned short\*(C'\fR and \f(CW\*(C`unsigned char\*(C'\fR promote -to \f(CW\*(C`unsigned int\*(C'\fR. -.Ip "\(bu" 4 -Out-of-range floating point literals are not an error. -.Ip "\(bu" 4 -Certain constructs which \s-1ISO\s0 regards as a single invalid preprocessing -number, such as \fB0xe-0xd\fR, are treated as expressions instead. -.Ip "\(bu" 4 -String ``constants'' are not necessarily constant; they are stored in -writable space, and identical looking constants are allocated -separately. (This is the same as the effect of -\&\fB\-fwritable-strings\fR.) -.Ip "\(bu" 4 -All automatic variables not declared \f(CW\*(C`register\*(C'\fR are preserved by -\&\f(CW\*(C`longjmp\*(C'\fR. Ordinarily, \s-1GNU\s0 C follows \s-1ISO\s0 C: automatic variables -not declared \f(CW\*(C`volatile\*(C'\fR may be clobbered. -.Ip "\(bu" 4 -The character escape sequences \fB\ex\fR and \fB\ea\fR evaluate as the -literal characters \fBx\fR and \fBa\fR respectively. Without -\&\fB\-traditional\fR, \fB\ex\fR is a prefix for the hexadecimal -representation of a character, and \fB\ea\fR produces a bell. -.RE -.RS 4 -.Sp -This option is deprecated and may be removed. -.Sp -You may wish to use \fB\-fno-builtin\fR as well as \fB\-traditional\fR -if your program uses names that are normally \s-1GNU\s0 C built-in functions for -other purposes of its own. -.Sp -You cannot use \fB\-traditional\fR if you include any header files that -rely on \s-1ISO\s0 C features. Some vendors are starting to ship systems with -\&\s-1ISO\s0 C header files and you cannot use \fB\-traditional\fR on such -systems to compile files that include any system headers. -.Sp -The \fB\-traditional\fR option also enables \fB\-traditional-cpp\fR. -.RE -.Ip "\fB\-traditional-cpp\fR" 4 +.PD 0 +.IP "\fB\-traditional\-cpp\fR" 4 .IX Item "-traditional-cpp" -Attempt to support some aspects of traditional C preprocessors. -See the \s-1GNU\s0 \s-1CPP\s0 manual for details. -.Ip "\fB\-fcond-mismatch\fR" 4 +.PD +Formerly, these options caused \s-1GCC\s0 to attempt to emulate a pre-standard +C compiler. They are now only supported with the \fB\-E\fR switch. +The preprocessor continues to support a pre-standard mode. See the \s-1GNU\s0 +\&\s-1CPP\s0 manual for details. +.IP "\fB\-fcond\-mismatch\fR" 4 .IX Item "-fcond-mismatch" Allow conditional expressions with mismatched types in the second and third arguments. The value of such an expression is void. This option is not supported for \*(C+. -.Ip "\fB\-funsigned-char\fR" 4 +.IP "\fB\-funsigned\-char\fR" 4 .IX Item "-funsigned-char" Let the type \f(CW\*(C`char\*(C'\fR be unsigned, like \f(CW\*(C`unsigned char\*(C'\fR. .Sp @@ -1180,51 +1150,37 @@ make such a program work with the opposite default. The type \f(CW\*(C`char\*(C'\fR is always a distinct type from each of \&\f(CW\*(C`signed char\*(C'\fR or \f(CW\*(C`unsigned char\*(C'\fR, even though its behavior is always just like one of those two. -.Ip "\fB\-fsigned-char\fR" 4 +.IP "\fB\-fsigned\-char\fR" 4 .IX Item "-fsigned-char" Let the type \f(CW\*(C`char\*(C'\fR be signed, like \f(CW\*(C`signed char\*(C'\fR. .Sp -Note that this is equivalent to \fB\-fno-unsigned-char\fR, which is -the negative form of \fB\-funsigned-char\fR. Likewise, the option -\&\fB\-fno-signed-char\fR is equivalent to \fB\-funsigned-char\fR. -.Ip "\fB\-fsigned-bitfields\fR" 4 +Note that this is equivalent to \fB\-fno\-unsigned\-char\fR, which is +the negative form of \fB\-funsigned\-char\fR. Likewise, the option +\&\fB\-fno\-signed\-char\fR is equivalent to \fB\-funsigned\-char\fR. +.IP "\fB\-fsigned\-bitfields\fR" 4 .IX Item "-fsigned-bitfields" .PD 0 -.Ip "\fB\-funsigned-bitfields\fR" 4 +.IP "\fB\-funsigned\-bitfields\fR" 4 .IX Item "-funsigned-bitfields" -.Ip "\fB\-fno-signed-bitfields\fR" 4 +.IP "\fB\-fno\-signed\-bitfields\fR" 4 .IX Item "-fno-signed-bitfields" -.Ip "\fB\-fno-unsigned-bitfields\fR" 4 +.IP "\fB\-fno\-unsigned\-bitfields\fR" 4 .IX Item "-fno-unsigned-bitfields" .PD These options control whether a bit-field is signed or unsigned, when the declaration does not use either \f(CW\*(C`signed\*(C'\fR or \f(CW\*(C`unsigned\*(C'\fR. By default, such a bit-field is signed, because this is consistent: the basic integer types such as \f(CW\*(C`int\*(C'\fR are signed types. -.Sp -However, when \fB\-traditional\fR is used, bit-fields are all unsigned -no matter what. -.Ip "\fB\-fwritable-strings\fR" 4 +.IP "\fB\-fwritable\-strings\fR" 4 .IX Item "-fwritable-strings" Store string constants in the writable data segment and don't uniquize them. This is for compatibility with old programs which assume they can -write into string constants. The option \fB\-traditional\fR also has -this effect. +write into string constants. .Sp Writing into string constants is a very bad idea; ``constants'' should be constant. -.Ip "\fB\-fallow-single-precision\fR" 4 -.IX Item "-fallow-single-precision" -Do not promote single precision math operations to double precision, -even when compiling with \fB\-traditional\fR. -.Sp -Traditional K&R C promotes all floating point operations to double -precision, regardless of the sizes of the operands. On the -architecture for which you are compiling, single precision may be faster -than double precision. If you must use \fB\-traditional\fR, but want -to use single precision operations when the operands are single -precision, use this option. This option has no effect when compiling -with \s-1ISO\s0 or \s-1GNU\s0 C conventions (the default). +.Sp +This option is deprecated. .Sh "Options Controlling \*(C+ Dialect" .IX Subsection "Options Controlling Dialect" This section describes the command-line options that are only meaningful @@ -1235,27 +1191,38 @@ might compile a file \f(CW\*(C`firstClass.C\*(C'\fR like this: .Vb 1 \& g++ -g -frepo -O -c firstClass.C .Ve +.PP In this example, only \fB\-frepo\fR is an option meant only for \*(C+ programs; you can use the other options with any language supported by \s-1GCC\s0. .PP Here is a list of options that are \fIonly\fR for compiling \*(C+ programs: -.Ip "\fB\-fno-access-control\fR" 4 +.IP "\fB\-fabi\-version=\fR\fIn\fR" 4 +.IX Item "-fabi-version=n" +Use version \fIn\fR of the \*(C+ \s-1ABI\s0. Version 2 is the version of the +\&\*(C+ \s-1ABI\s0 that first appeared in G++ 3.4. Version 1 is the version of +the \*(C+ \s-1ABI\s0 that first appeared in G++ 3.2. Version 0 will always be +the version that conforms most closely to the \*(C+ \s-1ABI\s0 specification. +Therefore, the \s-1ABI\s0 obtained using version 0 will change as \s-1ABI\s0 bugs +are fixed. +.Sp +The default is version 2. +.IP "\fB\-fno\-access\-control\fR" 4 .IX Item "-fno-access-control" Turn off all access checking. This switch is mainly useful for working around bugs in the access control code. -.Ip "\fB\-fcheck-new\fR" 4 +.IP "\fB\-fcheck\-new\fR" 4 .IX Item "-fcheck-new" Check that the pointer returned by \f(CW\*(C`operator new\*(C'\fR is non-null -before attempting to modify the storage allocated. The current Working -Paper requires that \f(CW\*(C`operator new\*(C'\fR never return a null pointer, so -this check is normally unnecessary. -.Sp -An alternative to using this option is to specify that your -\&\f(CW\*(C`operator new\*(C'\fR does not throw any exceptions; if you declare it -\&\fB\f(BIthrow()\fB\fR, G++ will check the return value. See also \fBnew -(nothrow)\fR. -.Ip "\fB\-fconserve-space\fR" 4 +before attempting to modify the storage allocated. This check is +normally unnecessary because the \*(C+ standard specifies that +\&\f(CW\*(C`operator new\*(C'\fR will only return \f(CW0\fR if it is declared +\&\fB\f(BIthrow()\fB\fR, in which case the compiler will always check the +return value even without this option. In all other cases, when +\&\f(CW\*(C`operator new\*(C'\fR has a non-empty exception specification, memory +exhaustion is signalled by throwing \f(CW\*(C`std::bad_alloc\*(C'\fR. See also +\&\fBnew (nothrow)\fR. +.IP "\fB\-fconserve\-space\fR" 4 .IX Item "-fconserve-space" Put uninitialized or runtime-initialized global variables into the common segment, as C does. This saves space in the executable at the @@ -1266,59 +1233,39 @@ two definitions were merged. .Sp This option is no longer useful on most targets, now that support has been added for putting variables into \s-1BSS\s0 without making them common. -.Ip "\fB\-fno-const-strings\fR" 4 +.IP "\fB\-fno\-const\-strings\fR" 4 .IX Item "-fno-const-strings" Give string constants type \f(CW\*(C`char *\*(C'\fR instead of type \f(CW\*(C`const char *\*(C'\fR. By default, G++ uses type \f(CW\*(C`const char *\*(C'\fR as required by -the standard. Even if you use \fB\-fno-const-strings\fR, you cannot +the standard. Even if you use \fB\-fno\-const\-strings\fR, you cannot actually modify the value of a string constant, unless you also use -\&\fB\-fwritable-strings\fR. +\&\fB\-fwritable\-strings\fR. .Sp This option might be removed in a future release of G++. For maximum portability, you should structure your code so that it works with string constants that have type \f(CW\*(C`const char *\*(C'\fR. -.Ip "\fB\-fdollars-in-identifiers\fR" 4 -.IX Item "-fdollars-in-identifiers" -Accept \fB$\fR in identifiers. You can also explicitly prohibit use of -\&\fB$\fR with the option \fB\-fno-dollars-in-identifiers\fR. (\s-1GNU\s0 C allows -\&\fB$\fR by default on most target systems, but there are a few exceptions.) -Traditional C allowed the character \fB$\fR to form part of -identifiers. However, \s-1ISO\s0 C and \*(C+ forbid \fB$\fR in identifiers. -.Ip "\fB\-fno-elide-constructors\fR" 4 +.IP "\fB\-fno\-elide\-constructors\fR" 4 .IX Item "-fno-elide-constructors" The \*(C+ standard allows an implementation to omit creating a temporary which is only used to initialize another object of the same type. Specifying this option disables that optimization, and forces G++ to call the copy constructor in all cases. -.Ip "\fB\-fno-enforce-eh-specs\fR" 4 +.IP "\fB\-fno\-enforce\-eh\-specs\fR" 4 .IX Item "-fno-enforce-eh-specs" Don't check for violation of exception specifications at runtime. This option violates the \*(C+ standard, but may be useful for reducing code size in production builds, much like defining \fB\s-1NDEBUG\s0\fR. The compiler will still optimize based on the exception specifications. -.Ip "\fB\-fexternal-templates\fR" 4 -.IX Item "-fexternal-templates" -Cause \fB#pragma interface\fR and \fBimplementation\fR to apply to -template instantiation; template instances are emitted or not according -to the location of the template definition. -.Sp -This option is deprecated. -.Ip "\fB\-falt-external-templates\fR" 4 -.IX Item "-falt-external-templates" -Similar to \fB\-fexternal-templates\fR, but template instances are -emitted or not according to the place where they are first instantiated. -.Sp -This option is deprecated. -.Ip "\fB\-ffor-scope\fR" 4 +.IP "\fB\-ffor\-scope\fR" 4 .IX Item "-ffor-scope" .PD 0 -.Ip "\fB\-fno-for-scope\fR" 4 +.IP "\fB\-fno\-for\-scope\fR" 4 .IX Item "-fno-for-scope" .PD -If \fB\-ffor-scope\fR is specified, the scope of variables declared in +If \fB\-ffor\-scope\fR is specified, the scope of variables declared in a \fIfor-init-statement\fR is limited to the \fBfor\fR loop itself, as specified by the \*(C+ standard. -If \fB\-fno-for-scope\fR is specified, the scope of variables declared in +If \fB\-fno\-for\-scope\fR is specified, the scope of variables declared in a \fIfor-init-statement\fR extends to the end of the enclosing scope, as was the case in old versions of G++, and other (traditional) implementations of \*(C+. @@ -1326,55 +1273,54 @@ implementations of \*(C+. The default if neither flag is given to follow the standard, but to allow and give a warning for old-style code that would otherwise be invalid, or have different behavior. -.Ip "\fB\-fno-gnu-keywords\fR" 4 +.IP "\fB\-fno\-gnu\-keywords\fR" 4 .IX Item "-fno-gnu-keywords" Do not recognize \f(CW\*(C`typeof\*(C'\fR as a keyword, so that code can use this word as an identifier. You can use the keyword \f(CW\*(C`_\|_typeof_\|_\*(C'\fR instead. -\&\fB\-ansi\fR implies \fB\-fno-gnu-keywords\fR. -.Ip "\fB\-fno-implicit-templates\fR" 4 +\&\fB\-ansi\fR implies \fB\-fno\-gnu\-keywords\fR. +.IP "\fB\-fno\-implicit\-templates\fR" 4 .IX Item "-fno-implicit-templates" Never emit code for non-inline templates which are instantiated implicitly (i.e. by use); only emit code for explicit instantiations. -.Ip "\fB\-fno-implicit-inline-templates\fR" 4 +.IP "\fB\-fno\-implicit\-inline\-templates\fR" 4 .IX Item "-fno-implicit-inline-templates" Don't emit code for implicit instantiations of inline templates, either. The default is to handle inlines differently so that compiles with and without optimization will need the same set of explicit instantiations. -.Ip "\fB\-fno-implement-inlines\fR" 4 +.IP "\fB\-fno\-implement\-inlines\fR" 4 .IX Item "-fno-implement-inlines" To save space, do not emit out-of-line copies of inline functions controlled by \fB#pragma implementation\fR. This will cause linker errors if these functions are not inlined everywhere they are called. -.Ip "\fB\-fms-extensions\fR" 4 +.IP "\fB\-fms\-extensions\fR" 4 .IX Item "-fms-extensions" Disable pedantic warnings about constructs used in \s-1MFC\s0, such as implicit int and getting a pointer to member function via non-standard syntax. -.Ip "\fB\-fno-nonansi-builtins\fR" 4 +.IP "\fB\-fno\-nonansi\-builtins\fR" 4 .IX Item "-fno-nonansi-builtins" Disable built-in declarations of functions that are not mandated by \&\s-1ANSI/ISO\s0 C. These include \f(CW\*(C`ffs\*(C'\fR, \f(CW\*(C`alloca\*(C'\fR, \f(CW\*(C`_exit\*(C'\fR, \&\f(CW\*(C`index\*(C'\fR, \f(CW\*(C`bzero\*(C'\fR, \f(CW\*(C`conjf\*(C'\fR, and other related functions. -.Ip "\fB\-fno-operator-names\fR" 4 +.IP "\fB\-fno\-operator\-names\fR" 4 .IX Item "-fno-operator-names" Do not treat the operator name keywords \f(CW\*(C`and\*(C'\fR, \f(CW\*(C`bitand\*(C'\fR, \&\f(CW\*(C`bitor\*(C'\fR, \f(CW\*(C`compl\*(C'\fR, \f(CW\*(C`not\*(C'\fR, \f(CW\*(C`or\*(C'\fR and \f(CW\*(C`xor\*(C'\fR as synonyms as keywords. -.Ip "\fB\-fno-optional-diags\fR" 4 +.IP "\fB\-fno\-optional\-diags\fR" 4 .IX Item "-fno-optional-diags" Disable diagnostics that the standard says a compiler does not need to issue. Currently, the only such diagnostic issued by G++ is the one for a name having multiple meanings within a class. -.Ip "\fB\-fpermissive\fR" 4 +.IP "\fB\-fpermissive\fR" 4 .IX Item "-fpermissive" -Downgrade messages about nonconformant code from errors to warnings. By -default, G++ effectively sets \fB\-pedantic-errors\fR without -\&\fB\-pedantic\fR; this option reverses that. This behavior and this -option are superseded by \fB\-pedantic\fR, which works as it does for \s-1GNU\s0 C. -.Ip "\fB\-frepo\fR" 4 +Downgrade some diagnostics about nonconformant code from errors to +warnings. Thus, using \fB\-fpermissive\fR will allow some +nonconforming code to compile. +.IP "\fB\-frepo\fR" 4 .IX Item "-frepo" Enable automatic template instantiation at link time. This option also -implies \fB\-fno-implicit-templates\fR. -.Ip "\fB\-fno-rtti\fR" 4 +implies \fB\-fno\-implicit\-templates\fR. +.IP "\fB\-fno\-rtti\fR" 4 .IX Item "-fno-rtti" Disable generation of information about every class with virtual functions for use by the \*(C+ runtime type identification features @@ -1382,41 +1328,31 @@ functions for use by the \*(C+ runtime type identification features of the language, you can save some space by using this flag. Note that exception handling uses the same information, but it will generate it as needed. -.Ip "\fB\-fstats\fR" 4 +.IP "\fB\-fstats\fR" 4 .IX Item "-fstats" Emit statistics about front-end processing at the end of the compilation. This information is generally only useful to the G++ development team. -.Ip "\fB\-ftemplate-depth-\fR\fIn\fR" 4 +.IP "\fB\-ftemplate\-depth\-\fR\fIn\fR" 4 .IX Item "-ftemplate-depth-n" Set the maximum instantiation depth for template classes to \fIn\fR. A limit on the template instantiation depth is needed to detect endless recursions during template class instantiation. \s-1ANSI/ISO\s0 \*(C+ conforming programs must not rely on a maximum depth greater than 17. -.Ip "\fB\-fuse-cxa-atexit\fR" 4 +.IP "\fB\-fuse\-cxa\-atexit\fR" 4 .IX Item "-fuse-cxa-atexit" Register destructors for objects with static storage duration with the \&\f(CW\*(C`_\|_cxa_atexit\*(C'\fR function rather than the \f(CW\*(C`atexit\*(C'\fR function. This option is required for fully standards-compliant handling of static destructors, but will only work if your C library supports \&\f(CW\*(C`_\|_cxa_atexit\*(C'\fR. -.Ip "\fB\-fvtable-gc\fR" 4 -.IX Item "-fvtable-gc" -Emit special relocations for vtables and virtual function references -so that the linker can identify unused virtual functions and zero out -vtable slots that refer to them. This is most useful with -\&\fB\-ffunction-sections\fR and \fB\-Wl,\-\-gc-sections\fR, in order to -also discard the functions themselves. -.Sp -This optimization requires \s-1GNU\s0 as and \s-1GNU\s0 ld. Not all systems support -this option. \fB\-Wl,\-\-gc-sections\fR is ignored without \fB\-static\fR. -.Ip "\fB\-fno-weak\fR" 4 +.IP "\fB\-fno\-weak\fR" 4 .IX Item "-fno-weak" Do not use weak symbol support, even if it is provided by the linker. By default, G++ will use weak symbols if they are available. This -option exists only for testing, and should not be used by end-users; +option exists only for testing, and should not be used by end\-users; it will result in inferior code and has no benefits. This option may be removed in a future release of G++. -.Ip "\fB\-nostdinc++\fR" 4 +.IP "\fB\-nostdinc++\fR" 4 .IX Item "-nostdinc++" Do not search for header files in the standard directories specific to \&\*(C+, but do still search the other standard directories. (This option @@ -1424,17 +1360,17 @@ is used when building the \*(C+ library.) .PP In addition, these optimization, warning, and code generation options have meanings only for \*(C+ programs: -.Ip "\fB\-fno-default-inline\fR" 4 +.IP "\fB\-fno\-default\-inline\fR" 4 .IX Item "-fno-default-inline" Do not assume \fBinline\fR for functions defined inside a class scope. Note that these functions will have linkage like inline functions; they just won't be inlined by default. -.Ip "\fB\-Wabi\fR (\*(C+ only)" 4 +.IP "\fB\-Wabi\fR (\*(C+ only)" 4 .IX Item "-Wabi ( only)" Warn when G++ generates code that is probably not compatible with the vendor-neutral \*(C+ \s-1ABI\s0. Although an effort has been made to warn about -all such cases, there are probably some cases that are not warned about, +all such cases, there are probably some cases that are not warned about, even though G++ is generating incompatible code. There may also be cases where warnings are emitted even though the code that is generated will be compatible. @@ -1443,22 +1379,23 @@ You should rewrite your code to avoid these warnings if you are concerned about the fact that code generated by G++ may not be binary compatible with code generated by other compilers. .Sp -The known incompatibilites at this point include: +The known incompatibilities at this point include: .RS 4 -.Ip "\(bu" 4 -Incorrect handling of tail-padding for bit-fields. G++ may attempt to +.IP "*" 4 +Incorrect handling of tail-padding for bit\-fields. G++ may attempt to pack data into the same byte as a base class. For example: .Sp .Vb 2 \& struct A { virtual void f(); int f1 : 1; }; \& struct B : public A { int f2 : 1; }; .Ve +.Sp In this case, G++ will place \f(CW\*(C`B::f2\*(C'\fR into the same byte -as\f(CW\*(C`A::f1\*(C'\fR; other compilers will not. You can avoid this problem +as\f(CW\*(C`A::f1\*(C'\fR; other compilers will not. You can avoid this problem by explicitly padding \f(CW\*(C`A\*(C'\fR so that its size is a multiple of the byte size on your platform; that will cause G++ and other compilers to layout \f(CW\*(C`B\*(C'\fR identically. -.Ip "\(bu" 4 +.IP "*" 4 Incorrect handling of tail-padding for virtual bases. G++ does not use tail padding when laying out virtual bases. For example: .Sp @@ -1467,24 +1404,73 @@ tail padding when laying out virtual bases. For example: \& struct B { B(); char c2; }; \& struct C : public A, public virtual B {}; .Ve +.Sp In this case, G++ will not place \f(CW\*(C`B\*(C'\fR into the tail-padding for \&\f(CW\*(C`A\*(C'\fR; other compilers will. You can avoid this problem by explicitly padding \f(CW\*(C`A\*(C'\fR so that its size is a multiple of its alignment (ignoring virtual base classes); that will cause G++ and other compilers to layout \f(CW\*(C`C\*(C'\fR identically. +.IP "*" 4 +Incorrect handling of bit-fields with declared widths greater than that +of their underlying types, when the bit-fields appear in a union. For +example: +.Sp +.Vb 1 +\& union U { int i : 4096; }; +.Ve +.Sp +Assuming that an \f(CW\*(C`int\*(C'\fR does not have 4096 bits, G++ will make the +union too small by the number of bits in an \f(CW\*(C`int\*(C'\fR. +.IP "*" 4 +Empty classes can be placed at incorrect offsets. For example: +.Sp +.Vb 1 +\& struct A {}; +.Ve +.Sp +.Vb 4 +\& struct B { +\& A a; +\& virtual void f (); +\& }; +.Ve +.Sp +.Vb 1 +\& struct C : public B, public A {}; +.Ve +.Sp +G++ will place the \f(CW\*(C`A\*(C'\fR base class of \f(CW\*(C`C\*(C'\fR at a nonzero offset; +it should be placed at offset zero. G++ mistakenly believes that the +\&\f(CW\*(C`A\*(C'\fR data member of \f(CW\*(C`B\*(C'\fR is already at offset zero. +.IP "*" 4 +Names of template functions whose types involve \f(CW\*(C`typename\*(C'\fR or +template template parameters can be mangled incorrectly. +.Sp +.Vb 2 +\& template <typename Q> +\& void f(typename Q::X) {} +.Ve +.Sp +.Vb 2 +\& template <template <typename> class Q> +\& void f(typename Q<int>::X) {} +.Ve +.Sp +Instantiations of these templates may be mangled incorrectly. .RE .RS 4 .RE -.Ip "\fB\-Wctor-dtor-privacy\fR (\*(C+ only)" 4 +.IP "\fB\-Wctor\-dtor\-privacy\fR (\*(C+ only)" 4 .IX Item "-Wctor-dtor-privacy ( only)" -Warn when a class seems unusable, because all the constructors or -destructors in a class are private and the class has no friends or +Warn when a class seems unusable because all the constructors or +destructors in that class are private, and it has neither friends nor public static member functions. -.Ip "\fB\-Wnon-virtual-dtor\fR (\*(C+ only)" 4 +.IP "\fB\-Wnon\-virtual\-dtor\fR (\*(C+ only)" 4 .IX Item "-Wnon-virtual-dtor ( only)" -Warn when a class declares a non-virtual destructor that should probably -be virtual, because it looks like the class will be used polymorphically. -.Ip "\fB\-Wreorder\fR (\*(C+ only)" 4 +Warn when a class appears to be polymorphic, thereby requiring a virtual +destructor, yet it declares a non-virtual one. +This warning is enabled by \fB\-Wall\fR. +.IP "\fB\-Wreorder\fR (\*(C+ only)" 4 .IX Item "-Wreorder ( only)" Warn when the order of member initializers given in the code does not match the order in which they must be executed. For instance: @@ -1496,71 +1482,70 @@ match the order in which they must be executed. For instance: \& A(): j (0), i (1) { } \& }; .Ve -Here the compiler will warn that the member initializers for \fBi\fR -and \fBj\fR will be rearranged to match the declaration order of the -members. +.Sp +The compiler will rearrange the member initializers for \fBi\fR +and \fBj\fR to match the declaration order of the members, emitting +a warning to that effect. This warning is enabled by \fB\-Wall\fR. .PP The following \fB\-W...\fR options are not affected by \fB\-Wall\fR. -.Ip "\fB\-Weffc++\fR (\*(C+ only)" 4 +.IP "\fB\-Weffc++\fR (\*(C+ only)" 4 .IX Item "-Weffc++ ( only)" Warn about violations of the following style guidelines from Scott Meyers' \&\fIEffective \*(C+\fR book: .RS 4 -.Ip "\(bu" 4 +.IP "*" 4 Item 11: Define a copy constructor and an assignment operator for classes with dynamically allocated memory. -.Ip "\(bu" 4 +.IP "*" 4 Item 12: Prefer initialization to assignment in constructors. -.Ip "\(bu" 4 +.IP "*" 4 Item 14: Make destructors virtual in base classes. -.Ip "\(bu" 4 -Item 15: Have \f(CW\*(C`operator=\*(C'\fR return a reference to \f(CW\*(C`*this\*(C'\fR. -.Ip "\(bu" 4 +.IP "*" 4 +Item 15: Have \f(CW\*(C`operator=\*(C'\fR return a reference to \f(CW*this\fR. +.IP "*" 4 Item 23: Don't try to return a reference when you must return an object. .RE .RS 4 .Sp -and about violations of the following style guidelines from Scott Meyers' -\&\fIMore Effective \*(C+\fR book: -.RS 4 -.RE -.Ip "\(bu" 4 +Also warn about violations of the following style guidelines from +Scott Meyers' \fIMore Effective \*(C+\fR book: +.IP "*" 4 Item 6: Distinguish between prefix and postfix forms of increment and decrement operators. -.Ip "\(bu" 4 +.IP "*" 4 Item 7: Never overload \f(CW\*(C`&&\*(C'\fR, \f(CW\*(C`||\*(C'\fR, or \f(CW\*(C`,\*(C'\fR. .RE .RS 4 .Sp -If you use this option, you should be aware that the standard library -headers do not obey all of these guidelines; you can use \fBgrep \-v\fR +When selecting this option, be aware that the standard library +headers do not obey all of these guidelines; use \fBgrep \-v\fR to filter out those warnings. .RE -.Ip "\fB\-Wno-deprecated\fR (\*(C+ only)" 4 +.IP "\fB\-Wno\-deprecated\fR (\*(C+ only)" 4 .IX Item "-Wno-deprecated ( only)" Do not warn about usage of deprecated features. -.Ip "\fB\-Wno-non-template-friend\fR (\*(C+ only)" 4 +.IP "\fB\-Wno\-non\-template\-friend\fR (\*(C+ only)" 4 .IX Item "-Wno-non-template-friend ( only)" Disable warnings when non-templatized friend functions are declared -within a template. With the advent of explicit template specification +within a template. Since the advent of explicit template specification support in G++, if the name of the friend is an unqualified-id (i.e., \&\fBfriend foo(int)\fR), the \*(C+ language specification demands that the friend declare or define an ordinary, nontemplate function. (Section 14.5.3). Before G++ implemented explicit specification, unqualified-ids could be interpreted as a particular specialization of a templatized function. Because this non-conforming behavior is no longer the default -behavior for G++, \fB\-Wnon-template-friend\fR allows the compiler to -check existing code for potential trouble spots, and is on by default. +behavior for G++, \fB\-Wnon\-template\-friend\fR allows the compiler to +check existing code for potential trouble spots and is on by default. This new compiler behavior can be turned off with -\&\fB\-Wno-non-template-friend\fR which keeps the conformant compiler code +\&\fB\-Wno\-non\-template\-friend\fR which keeps the conformant compiler code but disables the helpful warning. -.Ip "\fB\-Wold-style-cast\fR (\*(C+ only)" 4 +.IP "\fB\-Wold\-style\-cast\fR (\*(C+ only)" 4 .IX Item "-Wold-style-cast ( only)" -Warn if an old-style (C-style) cast to a non-void type is used within +Warn if an old-style (C\-style) cast to a non-void type is used within a \*(C+ program. The new-style casts (\fBstatic_cast\fR, \&\fBreinterpret_cast\fR, and \fBconst_cast\fR) are less vulnerable to -unintended effects, and much easier to grep for. -.Ip "\fB\-Woverloaded-virtual\fR (\*(C+ only)" 4 +unintended effects and much easier to search for. +.IP "\fB\-Woverloaded\-virtual\fR (\*(C+ only)" 4 .IX Item "-Woverloaded-virtual ( only)" Warn when a function declaration hides virtual functions from a base class. For example, in: @@ -1570,33 +1555,32 @@ base class. For example, in: \& virtual void f(); \& }; .Ve +.Sp .Vb 3 \& struct B: public A { \& void f(int); \& }; .Ve +.Sp the \f(CW\*(C`A\*(C'\fR class version of \f(CW\*(C`f\*(C'\fR is hidden in \f(CW\*(C`B\*(C'\fR, and code -like this: +like: .Sp .Vb 2 \& B* b; \& b->f(); .Ve +.Sp will fail to compile. -.Ip "\fB\-Wno-pmf-conversions\fR (\*(C+ only)" 4 +.IP "\fB\-Wno\-pmf\-conversions\fR (\*(C+ only)" 4 .IX Item "-Wno-pmf-conversions ( only)" Disable the diagnostic for converting a bound pointer to member function to a plain pointer. -.Ip "\fB\-Wsign-promo\fR (\*(C+ only)" 4 +.IP "\fB\-Wsign\-promo\fR (\*(C+ only)" 4 .IX Item "-Wsign-promo ( only)" Warn when overload resolution chooses a promotion from unsigned or -enumeral type to a signed type over a conversion to an unsigned type of +enumerated type to a signed type, over a conversion to an unsigned type of the same size. Previous versions of G++ would try to preserve unsignedness, but the standard mandates the current behavior. -.Ip "\fB\-Wsynth\fR (\*(C+ only)" 4 -.IX Item "-Wsynth ( only)" -Warn when G++'s synthesis behavior does not match that of cfront. For -instance: .Sp .Vb 4 \& struct A { @@ -1604,6 +1588,7 @@ instance: \& A& operator = (int); \& }; .Ve +.Sp .Vb 5 \& main () \& { @@ -1611,48 +1596,206 @@ instance: \& a = b; \& } .Ve +.Sp In this example, G++ will synthesize a default \fBA& operator = (const A&);\fR, while cfront will use the user-defined \fBoperator =\fR. .Sh "Options Controlling Objective-C Dialect" .IX Subsection "Options Controlling Objective-C Dialect" +(\s-1NOTE:\s0 This manual does not describe the Objective-C language itself. See +<\fBhttp://gcc.gnu.org/readings.html\fR> for references.) +.PP This section describes the command-line options that are only meaningful -for Objective-C programs; but you can also use most of the \s-1GNU\s0 compiler +for Objective-C programs, but you can also use most of the \s-1GNU\s0 compiler options regardless of what language your program is in. For example, you might compile a file \f(CW\*(C`some_class.m\*(C'\fR like this: .PP .Vb 1 \& gcc -g -fgnu-runtime -O -c some_class.m .Ve -In this example, only \fB\-fgnu-runtime\fR is an option meant only for +.PP +In this example, \fB\-fgnu\-runtime\fR is an option meant only for Objective-C programs; you can use the other options with any language supported by \s-1GCC\s0. .PP Here is a list of options that are \fIonly\fR for compiling Objective-C programs: -.Ip "\fB\-fconstant-string-class=\fR\fIclass-name\fR" 4 +.IP "\fB\-fconstant\-string\-class=\fR\fIclass-name\fR" 4 .IX Item "-fconstant-string-class=class-name" Use \fIclass-name\fR as the name of the class to instantiate for each literal string specified with the syntax \f(CW\*(C`@"..."\*(C'\fR. The default -class name is \f(CW\*(C`NXConstantString\*(C'\fR. -.Ip "\fB\-fgnu-runtime\fR" 4 +class name is \f(CW\*(C`NXConstantString\*(C'\fR if the \s-1GNU\s0 runtime is being used, and +\&\f(CW\*(C`NSConstantString\*(C'\fR if the NeXT runtime is being used (see below). The +\&\fB\-fconstant\-cfstrings\fR option, if also present, will override the +\&\fB\-fconstant\-string\-class\fR setting and cause \f(CW\*(C`@"..."\*(C'\fR literals +to be laid out as constant CoreFoundation strings. +.IP "\fB\-fgnu\-runtime\fR" 4 .IX Item "-fgnu-runtime" Generate object code compatible with the standard \s-1GNU\s0 Objective-C runtime. This is the default for most types of systems. -.Ip "\fB\-fnext-runtime\fR" 4 +.IP "\fB\-fnext\-runtime\fR" 4 .IX Item "-fnext-runtime" Generate output compatible with the NeXT runtime. This is the default -for NeXT-based systems, including Darwin and Mac \s-1OS\s0 X. -.Ip "\fB\-gen-decls\fR" 4 +for NeXT-based systems, including Darwin and Mac \s-1OS\s0 X. The macro +\&\f(CW\*(C`_\|_NEXT_RUNTIME_\|_\*(C'\fR is predefined if (and only if) this option is +used. +.IP "\fB\-fno\-nil\-receivers\fR" 4 +.IX Item "-fno-nil-receivers" +Assume that all Objective-C message dispatches (e.g., +\&\f(CW\*(C`[receiver message:arg]\*(C'\fR) in this translation unit ensure that the receiver +is not \f(CW\*(C`nil\*(C'\fR. This allows for more efficient entry points in the runtime to be +used. Currently, this option is only available in conjunction with +the NeXT runtime on Mac \s-1OS\s0 X 10.3 and later. +.IP "\fB\-fobjc\-exceptions\fR" 4 +.IX Item "-fobjc-exceptions" +Enable syntactic support for structured exception handling in Objective\-C, +similar to what is offered by \*(C+ and Java. Currently, this option is only +available in conjunction with the NeXT runtime on Mac \s-1OS\s0 X 10.3 and later. +.Sp +.Vb 23 +\& @try { +\& ... +\& @throw expr; +\& ... +\& } +\& @catch (AnObjCClass *exc) { +\& ... +\& @throw expr; +\& ... +\& @throw; +\& ... +\& } +\& @catch (AnotherClass *exc) { +\& ... +\& } +\& @catch (id allOthers) { +\& ... +\& } +\& @finally { +\& ... +\& @throw expr; +\& ... +\& } +.Ve +.Sp +The \f(CW@throw\fR statement may appear anywhere in an Objective-C or +Objective\-\*(C+ program; when used inside of a \f(CW@catch\fR block, the +\&\f(CW@throw\fR may appear without an argument (as shown above), in which case +the object caught by the \f(CW@catch\fR will be rethrown. +.Sp +Note that only (pointers to) Objective-C objects may be thrown and +caught using this scheme. When an object is thrown, it will be caught +by the nearest \f(CW@catch\fR clause capable of handling objects of that type, +analogously to how \f(CW\*(C`catch\*(C'\fR blocks work in \*(C+ and Java. A +\&\f(CW\*(C`@catch(id ...)\*(C'\fR clause (as shown above) may also be provided to catch +any and all Objective-C exceptions not caught by previous \f(CW@catch\fR +clauses (if any). +.Sp +The \f(CW@finally\fR clause, if present, will be executed upon exit from the +immediately preceding \f(CW\*(C`@try ... @catch\*(C'\fR section. This will happen +regardless of whether any exceptions are thrown, caught or rethrown +inside the \f(CW\*(C`@try ... @catch\*(C'\fR section, analogously to the behavior +of the \f(CW\*(C`finally\*(C'\fR clause in Java. +.Sp +There are several caveats to using the new exception mechanism: +.RS 4 +.IP "*" 4 +Although currently designed to be binary compatible with \f(CW\*(C`NS_HANDLER\*(C'\fR\-style +idioms provided by the \f(CW\*(C`NSException\*(C'\fR class, the new +exceptions can only be used on Mac \s-1OS\s0 X 10.3 (Panther) and later +systems, due to additional functionality needed in the (NeXT) Objective-C +runtime. +.IP "*" 4 +As mentioned above, the new exceptions do not support handling +types other than Objective-C objects. Furthermore, when used from +Objective\-\*(C+, the Objective-C exception model does not interoperate with \*(C+ +exceptions at this time. This means you cannot \f(CW@throw\fR an exception +from Objective-C and \f(CW\*(C`catch\*(C'\fR it in \*(C+, or vice versa +(i.e., \f(CW\*(C`throw ... @catch\*(C'\fR). +.RE +.RS 4 +.Sp +The \fB\-fobjc\-exceptions\fR switch also enables the use of synchronization +blocks for thread-safe execution: +.Sp +.Vb 3 +\& @synchronized (ObjCClass *guard) { +\& ... +\& } +.Ve +.Sp +Upon entering the \f(CW@synchronized\fR block, a thread of execution shall +first check whether a lock has been placed on the corresponding \f(CW\*(C`guard\*(C'\fR +object by another thread. If it has, the current thread shall wait until +the other thread relinquishes its lock. Once \f(CW\*(C`guard\*(C'\fR becomes available, +the current thread will place its own lock on it, execute the code contained in +the \f(CW@synchronized\fR block, and finally relinquish the lock (thereby +making \f(CW\*(C`guard\*(C'\fR available to other threads). +.Sp +Unlike Java, Objective-C does not allow for entire methods to be marked +\&\f(CW@synchronized\fR. Note that throwing exceptions out of +\&\f(CW@synchronized\fR blocks is allowed, and will cause the guarding object +to be unlocked properly. +.RE +.IP "\fB\-freplace\-objc\-classes\fR" 4 +.IX Item "-freplace-objc-classes" +Emit a special marker instructing \fB\f(BIld\fB\|(1)\fR not to statically link in +the resulting object file, and allow \fB\f(BIdyld\fB\|(1)\fR to load it in at +run time instead. This is used in conjunction with the Fix-and-Continue +debugging mode, where the object file in question may be recompiled and +dynamically reloaded in the course of program execution, without the need +to restart the program itself. Currently, Fix-and-Continue functionality +is only available in conjunction with the NeXT runtime on Mac \s-1OS\s0 X 10.3 +and later. +.IP "\fB\-fzero\-link\fR" 4 +.IX Item "-fzero-link" +When compiling for the NeXT runtime, the compiler ordinarily replaces calls +to \f(CW\*(C`objc_getClass("...")\*(C'\fR (when the name of the class is known at +compile time) with static class references that get initialized at load time, +which improves run-time performance. Specifying the \fB\-fzero\-link\fR flag +suppresses this behavior and causes calls to \f(CW\*(C`objc_getClass("...")\*(C'\fR +to be retained. This is useful in Zero-Link debugging mode, since it allows +for individual class implementations to be modified during program execution. +.IP "\fB\-gen\-decls\fR" 4 .IX Item "-gen-decls" Dump interface declarations for all classes seen in the source file to a file named \fI\fIsourcename\fI.decl\fR. -.Ip "\fB\-Wno-protocol\fR" 4 +.IP "\fB\-Wno\-protocol\fR" 4 .IX Item "-Wno-protocol" -Do not warn if methods required by a protocol are not implemented -in the class adopting it. -.Ip "\fB\-Wselector\fR" 4 +If a class is declared to implement a protocol, a warning is issued for +every method in the protocol that is not implemented by the class. The +default behavior is to issue a warning for every method not explicitly +implemented in the class, even if a method implementation is inherited +from the superclass. If you use the \f(CW\*(C`\-Wno\-protocol\*(C'\fR option, then +methods inherited from the superclass are considered to be implemented, +and no warning is issued for them. +.IP "\fB\-Wselector\fR" 4 .IX Item "-Wselector" -Warn if a selector has multiple methods of different types defined. +Warn if multiple methods of different types for the same selector are +found during compilation. The check is performed on the list of methods +in the final stage of compilation. Additionally, a check is performed +for each selector appearing in a \f(CW\*(C`@selector(...)\*(C'\fR +expression, and a corresponding method for that selector has been found +during compilation. Because these checks scan the method table only at +the end of compilation, these warnings are not produced if the final +stage of compilation is not reached, for example because an error is +found during compilation, or because the \f(CW\*(C`\-fsyntax\-only\*(C'\fR option is +being used. +.IP "\fB\-Wundeclared\-selector\fR" 4 +.IX Item "-Wundeclared-selector" +Warn if a \f(CW\*(C`@selector(...)\*(C'\fR expression referring to an +undeclared selector is found. A selector is considered undeclared if no +method with that name has been declared before the +\&\f(CW\*(C`@selector(...)\*(C'\fR expression, either explicitly in an +\&\f(CW@interface\fR or \f(CW@protocol\fR declaration, or implicitly in +an \f(CW@implementation\fR section. This option always performs its +checks as soon as a \f(CW\*(C`@selector(...)\*(C'\fR expression is found, +while \f(CW\*(C`\-Wselector\*(C'\fR only performs its checks in the final stage of +compilation. This also enforces the coding style convention +that methods and selectors must be declared before being used. +.IP "\fB\-print\-objc\-runtime\-info\fR" 4 +.IX Item "-print-objc-runtime-info" +Generate C header describing the largest structure that is passed by +value, if any. .Sh "Options to Control Diagnostic Messages Formatting" .IX Subsection "Options to Control Diagnostic Messages Formatting" Traditionally, diagnostic messages have been formatted irrespective of @@ -1662,14 +1805,14 @@ algorithm, e.g. how many characters per line, how often source location information should be reported. Right now, only the \*(C+ front end can honor these options. However it is expected, in the near future, that the remaining front ends would be able to digest them correctly. -.Ip "\fB\-fmessage-length=\fR\fIn\fR" 4 +.IP "\fB\-fmessage\-length=\fR\fIn\fR" 4 .IX Item "-fmessage-length=n" Try to format error messages so that they fit on lines of about \fIn\fR characters. The default is 72 characters for \fBg++\fR and 0 for the rest of the front ends supported by \s-1GCC\s0. If \fIn\fR is zero, then no line-wrapping will be done; each error message will appear on a single line. -.Ip "\fB\-fdiagnostics-show-location=once\fR" 4 +.IP "\fB\-fdiagnostics\-show\-location=once\fR" 4 .IX Item "-fdiagnostics-show-location=once" Only meaningful in line-wrapping mode. Instructs the diagnostic messages reporter to emit \fIonce\fR source location information; that is, in @@ -1677,7 +1820,7 @@ case the message is too long to fit on a single physical line and has to be wrapped, the source location won't be emitted (as prefix) again, over and over, in subsequent continuation lines. This is the default behavior. -.Ip "\fB\-fdiagnostics-show-location=every-line\fR" 4 +.IP "\fB\-fdiagnostics\-show\-location=every\-line\fR" 4 .IX Item "-fdiagnostics-show-location=every-line" Only meaningful in line-wrapping mode. Instructs the diagnostic messages reporter to emit the same source location information (as @@ -1692,17 +1835,17 @@ may have been an error. You can request many specific warnings with options beginning \fB\-W\fR, for example \fB\-Wimplicit\fR to request warnings on implicit declarations. Each of these specific warning options also has a -negative form beginning \fB\-Wno-\fR to turn off warnings; -for example, \fB\-Wno-implicit\fR. This manual lists only one of the +negative form beginning \fB\-Wno\-\fR to turn off warnings; +for example, \fB\-Wno\-implicit\fR. This manual lists only one of the two forms, whichever is not the default. .PP The following options control the amount and kinds of warnings produced by \s-1GCC\s0; for further, language-specific options also refer to -\&\f(CW@ref\fR{\*(C+ Dialect Options} and \f(CW@ref\fR{Objective-C Dialect Options}. -.Ip "\fB\-fsyntax-only\fR" 4 +\&\fB\*(C+ Dialect Options\fR and \fBObjective-C Dialect Options\fR. +.IP "\fB\-fsyntax\-only\fR" 4 .IX Item "-fsyntax-only" Check the code for syntax errors, but don't do anything beyond that. -.Ip "\fB\-pedantic\fR" 4 +.IP "\fB\-pedantic\fR" 4 .IX Item "-pedantic" Issue all the warnings demanded by strict \s-1ISO\s0 C and \s-1ISO\s0 \*(C+; reject all programs that use forbidden extensions, and some other @@ -1741,26 +1884,26 @@ for such warnings to be given only for features not in the specified \s-1GNU\s0 C dialect, since by definition the \s-1GNU\s0 dialects of C include all features the compiler supports with the given option, and there would be nothing to warn about.) -.Ip "\fB\-pedantic-errors\fR" 4 +.IP "\fB\-pedantic\-errors\fR" 4 .IX Item "-pedantic-errors" Like \fB\-pedantic\fR, except that errors are produced rather than warnings. -.Ip "\fB\-w\fR" 4 +.IP "\fB\-w\fR" 4 .IX Item "-w" Inhibit all warning messages. -.Ip "\fB\-Wno-import\fR" 4 +.IP "\fB\-Wno\-import\fR" 4 .IX Item "-Wno-import" Inhibit warning messages about the use of \fB#import\fR. -.Ip "\fB\-Wchar-subscripts\fR" 4 +.IP "\fB\-Wchar\-subscripts\fR" 4 .IX Item "-Wchar-subscripts" Warn if an array subscript has type \f(CW\*(C`char\*(C'\fR. This is a common cause of error, as programmers often forget that this type is signed on some machines. -.Ip "\fB\-Wcomment\fR" 4 +.IP "\fB\-Wcomment\fR" 4 .IX Item "-Wcomment" Warn whenever a comment-start sequence \fB/*\fR appears in a \fB/*\fR comment, or whenever a Backslash-Newline appears in a \fB//\fR comment. -.Ip "\fB\-Wformat\fR" 4 +.IP "\fB\-Wformat\fR" 4 .IX Item "-Wformat" Check calls to \f(CW\*(C`printf\*(C'\fR and \f(CW\*(C`scanf\*(C'\fR, etc., to make sure that the arguments supplied have types appropriate to the format string @@ -1771,7 +1914,7 @@ attributes, in the \f(CW\*(C`printf\*(C'\fR, not in the C standard) families. .Sp The formats are checked against the format features supported by \s-1GNU\s0 -libc version 2.2. These include all \s-1ISO\s0 C89 and C99 features, as well +libc version 2.2. These include all \s-1ISO\s0 C90 and C99 features, as well as features from the Single Unix Specification and some \s-1BSD\s0 and \s-1GNU\s0 extensions. Other library implementations may not support all these features; \s-1GCC\s0 does not support warning about features that go beyond a @@ -1780,16 +1923,19 @@ with \fB\-Wformat\fR, warnings will be given about format features not in the selected standard version (but not for \f(CW\*(C`strfmon\*(C'\fR formats, since those are not in any version of the C standard). .Sp +Since \fB\-Wformat\fR also checks for null format arguments for +several functions, \fB\-Wformat\fR also implies \fB\-Wnonnull\fR. +.Sp \&\fB\-Wformat\fR is included in \fB\-Wall\fR. For more control over some -aspects of format checking, the options \fB\-Wno-format-y2k\fR, -\&\fB\-Wno-format-extra-args\fR, \fB\-Wformat-nonliteral\fR, -\&\fB\-Wformat-security\fR and \fB\-Wformat=2\fR are available, but are -not included in \fB\-Wall\fR. -.Ip "\fB\-Wno-format-y2k\fR" 4 -.IX Item "-Wno-format-y2k" -If \fB\-Wformat\fR is specified, do not warn about \f(CW\*(C`strftime\*(C'\fR +aspects of format checking, the options \fB\-Wformat\-y2k\fR, +\&\fB\-Wno\-format\-extra\-args\fR, \fB\-Wno\-format\-zero\-length\fR, +\&\fB\-Wformat\-nonliteral\fR, \fB\-Wformat\-security\fR, and +\&\fB\-Wformat=2\fR are available, but are not included in \fB\-Wall\fR. +.IP "\fB\-Wformat\-y2k\fR" 4 +.IX Item "-Wformat-y2k" +If \fB\-Wformat\fR is specified, also warn about \f(CW\*(C`strftime\*(C'\fR formats which may yield only a two-digit year. -.Ip "\fB\-Wno-format-extra-args\fR" 4 +.IP "\fB\-Wno\-format\-extra\-args\fR" 4 .IX Item "-Wno-format-extra-args" If \fB\-Wformat\fR is specified, do not warn about excess arguments to a \&\f(CW\*(C`printf\*(C'\fR or \f(CW\*(C`scanf\*(C'\fR format function. The C standard specifies @@ -1802,12 +1948,16 @@ type to pass to \f(CW\*(C`va_arg\*(C'\fR to skip the unused arguments. However, in the case of \f(CW\*(C`scanf\*(C'\fR formats, this option will suppress the warning if the unused arguments are all pointers, since the Single Unix Specification says that such unused arguments are allowed. -.Ip "\fB\-Wformat-nonliteral\fR" 4 +.IP "\fB\-Wno\-format\-zero\-length\fR" 4 +.IX Item "-Wno-format-zero-length" +If \fB\-Wformat\fR is specified, do not warn about zero-length formats. +The C standard specifies that zero-length formats are allowed. +.IP "\fB\-Wformat\-nonliteral\fR" 4 .IX Item "-Wformat-nonliteral" If \fB\-Wformat\fR is specified, also warn if the format string is not a string literal and so cannot be checked, unless the format function takes its format arguments as a \f(CW\*(C`va_list\*(C'\fR. -.Ip "\fB\-Wformat-security\fR" 4 +.IP "\fB\-Wformat\-security\fR" 4 .IX Item "-Wformat-security" If \fB\-Wformat\fR is specified, also warn about uses of format functions that represent possible security problems. At present, this @@ -1815,34 +1965,57 @@ warns about calls to \f(CW\*(C`printf\*(C'\fR and \f(CW\*(C`scanf\*(C'\fR functi format string is not a string literal and there are no format arguments, as in \f(CW\*(C`printf (foo);\*(C'\fR. This may be a security hole if the format string came from untrusted input and contains \fB%n\fR. (This is -currently a subset of what \fB\-Wformat-nonliteral\fR warns about, but -in future warnings may be added to \fB\-Wformat-security\fR that are not -included in \fB\-Wformat-nonliteral\fR.) -.Ip "\fB\-Wformat=2\fR" 4 +currently a subset of what \fB\-Wformat\-nonliteral\fR warns about, but +in future warnings may be added to \fB\-Wformat\-security\fR that are not +included in \fB\-Wformat\-nonliteral\fR.) +.IP "\fB\-Wformat=2\fR" 4 .IX Item "-Wformat=2" Enable \fB\-Wformat\fR plus format checks not included in \&\fB\-Wformat\fR. Currently equivalent to \fB\-Wformat -\&\-Wformat-nonliteral \-Wformat-security\fR. -.Ip "\fB\-Wimplicit-int\fR" 4 +\&\-Wformat\-nonliteral \-Wformat\-security \-Wformat\-y2k\fR. +.IP "\fB\-Wnonnull\fR" 4 +.IX Item "-Wnonnull" +Warn about passing a null pointer for arguments marked as +requiring a non-null value by the \f(CW\*(C`nonnull\*(C'\fR function attribute. +.Sp +\&\fB\-Wnonnull\fR is included in \fB\-Wall\fR and \fB\-Wformat\fR. It +can be disabled with the \fB\-Wno\-nonnull\fR option. +.IP "\fB\-Winit\-self\fR (C, \*(C+, and Objective-C only)" 4 +.IX Item "-Winit-self (C, , and Objective-C only)" +Warn about uninitialized variables which are initialized with themselves. +Note this option can only be used with the \fB\-Wuninitialized\fR option, +which in turn only works with \fB\-O1\fR and above. +.Sp +For example, \s-1GCC\s0 will warn about \f(CW\*(C`i\*(C'\fR being uninitialized in the +following snippet only when \fB\-Winit\-self\fR has been specified: +.Sp +.Vb 5 +\& int f() +\& { +\& int i = i; +\& return i; +\& } +.Ve +.IP "\fB\-Wimplicit\-int\fR" 4 .IX Item "-Wimplicit-int" Warn when a declaration does not specify a type. -.Ip "\fB\-Wimplicit-function-declaration\fR" 4 +.IP "\fB\-Wimplicit\-function\-declaration\fR" 4 .IX Item "-Wimplicit-function-declaration" .PD 0 -.Ip "\fB\-Werror-implicit-function-declaration\fR" 4 +.IP "\fB\-Werror\-implicit\-function\-declaration\fR" 4 .IX Item "-Werror-implicit-function-declaration" .PD Give a warning (or error) whenever a function is used before being declared. -.Ip "\fB\-Wimplicit\fR" 4 +.IP "\fB\-Wimplicit\fR" 4 .IX Item "-Wimplicit" -Same as \fB\-Wimplicit-int\fR and \fB\-Wimplicit-function-declaration\fR. -.Ip "\fB\-Wmain\fR" 4 +Same as \fB\-Wimplicit\-int\fR and \fB\-Wimplicit\-function\-declaration\fR. +.IP "\fB\-Wmain\fR" 4 .IX Item "-Wmain" Warn if the type of \fBmain\fR is suspicious. \fBmain\fR should be a function with external linkage, returning int, taking either zero arguments, two, or three arguments of appropriate types. -.Ip "\fB\-Wmissing-braces\fR" 4 +.IP "\fB\-Wmissing\-braces\fR" 4 .IX Item "-Wmissing-braces" Warn if an aggregate or union initializer is not fully bracketed. In the following example, the initializer for \fBa\fR is not fully @@ -1852,7 +2025,7 @@ bracketed, but that for \fBb\fR is fully bracketed. \& int a[2][2] = { 0, 1, 2, 3 }; \& int b[2][2] = { { 0, 1 }, { 2, 3 } }; .Ve -.Ip "\fB\-Wparentheses\fR" 4 +.IP "\fB\-Wparentheses\fR" 4 .IX Item "-Wparentheses" Warn if parentheses are omitted in certain contexts, such as when there is an assignment in a context where a truth value @@ -1872,6 +2045,7 @@ such a case: \& bar (); \& } .Ve +.Sp In C, every \f(CW\*(C`else\*(C'\fR branch belongs to the innermost possible \f(CW\*(C`if\*(C'\fR statement, which in this example is \f(CW\*(C`if (b)\*(C'\fR. This is often not what the programmer expected, as illustrated in the above example by @@ -1892,7 +2066,7 @@ the enclosing \f(CW\*(C`if\*(C'\fR. The resulting code would look like this: \& } \& } .Ve -.Ip "\fB\-Wsequence-point\fR" 4 +.IP "\fB\-Wsequence\-point\fR" 4 .IX Item "-Wsequence-point" Warn about code that may have undefined semantics because of violations of sequence point rules in the C standard. @@ -1935,61 +2109,71 @@ future implementation may also work for \*(C+ programs. The C standard is worded confusingly, therefore there is some debate over the precise meaning of the sequence point rules in subtle cases. Links to discussions of the problem, including proposed formal -definitions, may be found on our readings page, at +definitions, may be found on the \s-1GCC\s0 readings page, at <\fBhttp://gcc.gnu.org/readings.html\fR>. -.Ip "\fB\-Wreturn-type\fR" 4 +.IP "\fB\-Wreturn\-type\fR" 4 .IX Item "-Wreturn-type" Warn whenever a function is defined with a return-type that defaults to \&\f(CW\*(C`int\*(C'\fR. Also warn about any \f(CW\*(C`return\*(C'\fR statement with no return-value in a function whose return-type is not \f(CW\*(C`void\*(C'\fR. .Sp For \*(C+, a function without return type always produces a diagnostic -message, even when \fB\-Wno-return-type\fR is specified. The only +message, even when \fB\-Wno\-return\-type\fR is specified. The only exceptions are \fBmain\fR and functions defined in system headers. -.Ip "\fB\-Wswitch\fR" 4 +.IP "\fB\-Wswitch\fR" 4 .IX Item "-Wswitch" -Warn whenever a \f(CW\*(C`switch\*(C'\fR statement has an index of enumeral type +Warn whenever a \f(CW\*(C`switch\*(C'\fR statement has an index of enumerated type and lacks a \f(CW\*(C`case\*(C'\fR for one or more of the named codes of that enumeration. (The presence of a \f(CW\*(C`default\*(C'\fR label prevents this warning.) \f(CW\*(C`case\*(C'\fR labels outside the enumeration range also provoke warnings when this option is used. -.Ip "\fB\-Wtrigraphs\fR" 4 +.IP "\fB\-Wswitch\-default\fR" 4 +.IX Item "-Wswitch-default" +Warn whenever a \f(CW\*(C`switch\*(C'\fR statement does not have a \f(CW\*(C`default\*(C'\fR +case. +.IP "\fB\-Wswitch\-enum\fR" 4 +.IX Item "-Wswitch-enum" +Warn whenever a \f(CW\*(C`switch\*(C'\fR statement has an index of enumerated type +and lacks a \f(CW\*(C`case\*(C'\fR for one or more of the named codes of that +enumeration. \f(CW\*(C`case\*(C'\fR labels outside the enumeration range also +provoke warnings when this option is used. +.IP "\fB\-Wtrigraphs\fR" 4 .IX Item "-Wtrigraphs" Warn if any trigraphs are encountered that might change the meaning of the program (trigraphs within comments are not warned about). -.Ip "\fB\-Wunused-function\fR" 4 +.IP "\fB\-Wunused\-function\fR" 4 .IX Item "-Wunused-function" Warn whenever a static function is declared but not defined or a -non\e-inline static function is unused. -.Ip "\fB\-Wunused-label\fR" 4 +non\e\-inline static function is unused. +.IP "\fB\-Wunused\-label\fR" 4 .IX Item "-Wunused-label" Warn whenever a label is declared but not used. .Sp To suppress this warning use the \fBunused\fR attribute. -.Ip "\fB\-Wunused-parameter\fR" 4 +.IP "\fB\-Wunused\-parameter\fR" 4 .IX Item "-Wunused-parameter" Warn whenever a function parameter is unused aside from its declaration. .Sp To suppress this warning use the \fBunused\fR attribute. -.Ip "\fB\-Wunused-variable\fR" 4 +.IP "\fB\-Wunused\-variable\fR" 4 .IX Item "-Wunused-variable" Warn whenever a local variable or non-constant static variable is unused aside from its declaration .Sp To suppress this warning use the \fBunused\fR attribute. -.Ip "\fB\-Wunused-value\fR" 4 +.IP "\fB\-Wunused\-value\fR" 4 .IX Item "-Wunused-value" Warn whenever a statement computes a result that is explicitly not used. .Sp To suppress this warning cast the expression to \fBvoid\fR. -.Ip "\fB\-Wunused\fR" 4 +.IP "\fB\-Wunused\fR" 4 .IX Item "-Wunused" -All all the above \fB\-Wunused\fR options combined. +All the above \fB\-Wunused\fR options combined. .Sp In order to get a warning about an unused function parameter, you must -either specify \fB\-W \-Wunused\fR or separately specify -\&\fB\-Wunused-parameter\fR. -.Ip "\fB\-Wuninitialized\fR" 4 +either specify \fB\-Wextra \-Wunused\fR (note that \fB\-Wall\fR implies +\&\fB\-Wunused\fR), or separately specify \fB\-Wunused\-parameter\fR. +.IP "\fB\-Wuninitialized\fR" 4 .IX Item "-Wuninitialized" Warn if an automatic variable is used without first being initialized or if a variable may be clobbered by a \f(CW\*(C`setjmp\*(C'\fR call. @@ -1999,6 +2183,9 @@ because they require data flow information that is computed only when optimizing. If you don't specify \fB\-O\fR, you simply won't get these warnings. .Sp +If you want to warn about code which uses the uninitialized value of the +variable in its own initializer, use the \fB\-Winit\-self\fR option. +.Sp These warnings occur only for variables that are candidates for register allocation. Therefore, they do not occur for a variable that is declared \f(CW\*(C`volatile\*(C'\fR, or whose address is taken, or whose size @@ -2029,6 +2216,7 @@ this can happen: \& foo (x); \& } .Ve +.Sp If the value of \f(CW\*(C`y\*(C'\fR is always 1, 2 or 3, then \f(CW\*(C`x\*(C'\fR is always initialized, but \s-1GCC\s0 doesn't know this. Here is another common case: @@ -2041,6 +2229,7 @@ another common case: \& if (change_y) y = save_y; \& } .Ve +.Sp This has no bug because \f(CW\*(C`save_y\*(C'\fR is used only if it is set. .Sp This option also warns when a non-volatile automatic variable might be @@ -2055,44 +2244,27 @@ in fact be called at the place which would cause a problem. .Sp Some spurious warnings can be avoided if you declare all the functions you use that never return as \f(CW\*(C`noreturn\*(C'\fR. -.Ip "\fB\-Wreorder\fR (\*(C+ only)" 4 -.IX Item "-Wreorder ( only)" -Warn when the order of member initializers given in the code does not -match the order in which they must be executed. For instance: -.Ip "\fB\-Wunknown-pragmas\fR" 4 +.IP "\fB\-Wunknown\-pragmas\fR" 4 .IX Item "-Wunknown-pragmas" Warn when a #pragma directive is encountered which is not understood by \&\s-1GCC\s0. If this command line option is used, warnings will even be issued for unknown pragmas in system header files. This is not the case if the warnings were only enabled by the \fB\-Wall\fR command line option. -.Ip "\fB\-Wall\fR" 4 +.IP "\fB\-Wstrict\-aliasing\fR" 4 +.IX Item "-Wstrict-aliasing" +This option is only active when \fB\-fstrict\-aliasing\fR is active. +It warns about code which might break the strict aliasing rules that the +compiler is using for optimization. The warning does not catch all +cases, but does attempt to catch the more common pitfalls. It is +included in \fB\-Wall\fR. +.IP "\fB\-Wall\fR" 4 .IX Item "-Wall" All of the above \fB\-W\fR options combined. This enables all the warnings about constructions that some users consider questionable, and that are easy to avoid (or modify to prevent the warning), even in -conjunction with macros. -.Ip "\fB\-Wdiv-by-zero\fR" 4 -.IX Item "-Wdiv-by-zero" -Warn about compile-time integer division by zero. This is default. To -inhibit the warning messages, use \fB\-Wno-div-by-zero\fR. Floating -point division by zero is not warned about, as it can be a legitimate -way of obtaining infinities and NaNs. -.Ip "\fB\-Wmultichar\fR" 4 -.IX Item "-Wmultichar" -Warn if a multicharacter constant (\fB'\s-1FOOF\s0'\fR) is used. This is -default. To inhibit the warning messages, use \fB\-Wno-multichar\fR. -Usually they indicate a typo in the user's code, as they have -implementation-defined values, and should not be used in portable code. -.Ip "\fB\-Wsystem-headers\fR" 4 -.IX Item "-Wsystem-headers" -Print warning messages for constructs found in system header files. -Warnings from system headers are normally suppressed, on the assumption -that they usually do not indicate real problems and would only make the -compiler output harder to read. Using this command line option tells -\&\s-1GCC\s0 to emit warnings from system headers as if they occurred in user -code. However, note that using \fB\-Wall\fR in conjunction with this -option will \fInot\fR warn about unknown pragmas in system -headers\-\-\-for that, \fB\-Wunknown-pragmas\fR must also be used. +conjunction with macros. This also enables some language-specific +warnings described in \fB\*(C+ Dialect Options\fR and +\&\fBObjective-C Dialect Options\fR. .PP The following \fB\-W...\fR options are not implied by \fB\-Wall\fR. Some of them warn about constructions that users generally do not @@ -2100,11 +2272,13 @@ consider questionable, but which occasionally you might wish to check for; others warn about constructions that are necessary or hard to avoid in some cases, and there is no simple way to modify the code to suppress the warning. -.Ip "\fB\-W\fR" 4 -.IX Item "-W" -Print extra warning messages for these events: +.IP "\fB\-Wextra\fR" 4 +.IX Item "-Wextra" +(This option used to be called \fB\-W\fR. The older name is still +supported, but the newer name is more descriptive.) Print extra warning +messages for these events: .RS 4 -.Ip "\(bu" 4 +.IP "*" 4 A function can return either with or without a value. (Falling off the end of the function body is considered returning without a value.) For example, this function would evoke such a @@ -2117,45 +2291,35 @@ warning: \& return a; \& } .Ve -.Ip "\(bu" 4 +.IP "*" 4 An expression-statement or the left-hand side of a comma expression contains no side effects. To suppress the warning, cast the unused expression to void. For example, an expression such as \fBx[i,j]\fR will cause a warning, but \fBx[(void)i,j]\fR will not. -.Ip "\(bu" 4 -An unsigned value is compared against zero with \fB<\fR or \fB<=\fR. -.Ip "\(bu" 4 +.IP "*" 4 +An unsigned value is compared against zero with \fB<\fR or \fB>=\fR. +.IP "*" 4 A comparison like \fBx<=y<=z\fR appears; this is equivalent to \&\fB(x<=y ? 1 : 0) <= z\fR, which is a different interpretation from that of ordinary mathematical notation. -.Ip "\(bu" 4 +.IP "*" 4 Storage-class specifiers like \f(CW\*(C`static\*(C'\fR are not the first things in a declaration. According to the C Standard, this usage is obsolescent. -.Ip "\(bu" 4 +.IP "*" 4 The return type of a function has a type qualifier such as \f(CW\*(C`const\*(C'\fR. Such a type qualifier has no effect, since the value returned by a function is not an lvalue. (But don't warn about the \s-1GNU\s0 extension of \&\f(CW\*(C`volatile void\*(C'\fR return types. That extension will be warned about if \fB\-pedantic\fR is specified.) -.Ip "\(bu" 4 +.IP "*" 4 If \fB\-Wall\fR or \fB\-Wunused\fR is also specified, warn about unused arguments. -.Ip "\(bu" 4 +.IP "*" 4 A comparison between signed and unsigned values could produce an incorrect result when the signed value is converted to unsigned. -(But don't warn if \fB\-Wno-sign-compare\fR is also specified.) -.Ip "\(bu" 4 -An aggregate has a partly bracketed initializer. -For example, the following code would evoke such a warning, -because braces are missing around the initializer for \f(CW\*(C`x.h\*(C'\fR: -.Sp -.Vb 3 -\& struct s { int f, g; }; -\& struct t { struct s h; int i; }; -\& struct t x = { 1, 2, 3 }; -.Ve -.Ip "\(bu" 4 +(But don't warn if \fB\-Wno\-sign\-compare\fR is also specified.) +.IP "*" 4 An aggregate has an initializer which does not initialize all members. For example, the following code would cause such a warning, because \&\f(CW\*(C`x.h\*(C'\fR would be implicitly initialized to zero: @@ -2164,34 +2328,85 @@ For example, the following code would cause such a warning, because \& struct s { int f, g, h; }; \& struct s x = { 3, 4 }; .Ve +.IP "*" 4 +A function parameter is declared without a type specifier in K&R\-style +functions: +.Sp +.Vb 1 +\& void foo(bar) { } +.Ve +.IP "*" 4 +An empty body occurs in an \fBif\fR or \fBelse\fR statement. +.IP "*" 4 +A pointer is compared against integer zero with \fB<\fR, \fB<=\fR, +\&\fB>\fR, or \fB>=\fR. +.IP "*" 4 +A variable might be changed by \fBlongjmp\fR or \fBvfork\fR. +.IP "*" 4 +Any of several floating-point events that often indicate errors, such as +overflow, underflow, loss of precision, etc. +.IP "*<(\*(C+ only)>" 4 +.IX Item "*<( only)>" +An enumerator and a non-enumerator both appear in a conditional expression. +.IP "*<(\*(C+ only)>" 4 +.IX Item "*<( only)>" +A non-static reference or non-static \fBconst\fR member appears in a +class without constructors. +.IP "*<(\*(C+ only)>" 4 +.IX Item "*<( only)>" +Ambiguous virtual bases. +.IP "*<(\*(C+ only)>" 4 +.IX Item "*<( only)>" +Subscripting an array which has been declared \fBregister\fR. +.IP "*<(\*(C+ only)>" 4 +.IX Item "*<( only)>" +Taking the address of a variable which has been declared \fBregister\fR. +.IP "*<(\*(C+ only)>" 4 +.IX Item "*<( only)>" +A base class is not initialized in a derived class' copy constructor. .RE .RS 4 .RE -.Ip "\fB\-Wfloat-equal\fR" 4 +.IP "\fB\-Wno\-div\-by\-zero\fR" 4 +.IX Item "-Wno-div-by-zero" +Do not warn about compile-time integer division by zero. Floating point +division by zero is not warned about, as it can be a legitimate way of +obtaining infinities and NaNs. +.IP "\fB\-Wsystem\-headers\fR" 4 +.IX Item "-Wsystem-headers" +Print warning messages for constructs found in system header files. +Warnings from system headers are normally suppressed, on the assumption +that they usually do not indicate real problems and would only make the +compiler output harder to read. Using this command line option tells +\&\s-1GCC\s0 to emit warnings from system headers as if they occurred in user +code. However, note that using \fB\-Wall\fR in conjunction with this +option will \fInot\fR warn about unknown pragmas in system +headers\-\-\-for that, \fB\-Wunknown\-pragmas\fR must also be used. +.IP "\fB\-Wfloat\-equal\fR" 4 .IX Item "-Wfloat-equal" Warn if floating point values are used in equality comparisons. .Sp The idea behind this is that sometimes it is convenient (for the programmer) to consider floating-point values as approximations to infinitely precise real numbers. If you are doing this, then you need -to compute (by analysing the code, or in some other way) the maximum or +to compute (by analyzing the code, or in some other way) the maximum or likely maximum error that the computation introduces, and allow for it when performing comparisons (and when producing output, but that's a different problem). In particular, instead of testing for equality, you would check to see whether the two values have ranges that overlap; and this is done with the relational operators, so equality comparisons are probably mistaken. -.Ip "\fB\-Wtraditional\fR (C only)" 4 +.IP "\fB\-Wtraditional\fR (C only)" 4 .IX Item "-Wtraditional (C only)" Warn about certain constructs that behave differently in traditional and \&\s-1ISO\s0 C. Also warn about \s-1ISO\s0 C constructs that have no traditional C equivalent, and/or problematic constructs which should be avoided. .RS 4 -.Ip "\(bu" 4 +.IP "*" 4 Macro parameters that appear within string literals in the macro body. In traditional C macro replacement takes place within string literals, but does not in \s-1ISO\s0 C. -.Ip "\(bu" 4 +.IP "*" 4 In traditional C, some preprocessor directives did not exist. Traditional preprocessors would only consider a line to be a directive if the \fB#\fR appeared in column 1 on the line. Therefore @@ -2201,88 +2416,105 @@ first character on the line. It also suggests you hide directives like \&\fB#pragma\fR not understood by traditional C by indenting them. Some traditional implementations would not recognize \fB#elif\fR, so it suggests avoiding it altogether. -.Ip "\(bu" 4 +.IP "*" 4 A function-like macro that appears without arguments. -.Ip "\(bu" 4 +.IP "*" 4 The unary plus operator. -.Ip "\(bu" 4 +.IP "*" 4 The \fBU\fR integer constant suffix, or the \fBF\fR or \fBL\fR floating point constant suffixes. (Traditional C does support the \fBL\fR suffix on integer constants.) Note, these suffixes appear in macros defined in the system headers of most modern systems, e.g. the \fB_MIN\fR/\fB_MAX\fR macros in \f(CW\*(C`<limits.h>\*(C'\fR. Use of these macros in user code might normally lead to spurious -warnings, however gcc's integrated preprocessor has enough context to +warnings, however \s-1GCC\s0's integrated preprocessor has enough context to avoid warning in these cases. -.Ip "\(bu" 4 +.IP "*" 4 A function declared external in one block and then used after the end of the block. -.Ip "\(bu" 4 +.IP "*" 4 A \f(CW\*(C`switch\*(C'\fR statement has an operand of type \f(CW\*(C`long\*(C'\fR. -.Ip "\(bu" 4 -A non-\f(CW\*(C`static\*(C'\fR function declaration follows a \f(CW\*(C`static\*(C'\fR one. +.IP "*" 4 +A non\-\f(CW\*(C`static\*(C'\fR function declaration follows a \f(CW\*(C`static\*(C'\fR one. This construct is not accepted by some traditional C compilers. -.Ip "\(bu" 4 +.IP "*" 4 The \s-1ISO\s0 type of an integer constant has a different width or signedness from its traditional type. This warning is only issued if the base of the constant is ten. I.e. hexadecimal or octal values, which typically represent bit patterns, are not warned about. -.Ip "\(bu" 4 +.IP "*" 4 Usage of \s-1ISO\s0 string concatenation is detected. -.Ip "\(bu" 4 +.IP "*" 4 Initialization of automatic aggregates. -.Ip "\(bu" 4 +.IP "*" 4 Identifier conflicts with labels. Traditional C lacks a separate namespace for labels. -.Ip "\(bu" 4 +.IP "*" 4 Initialization of unions. If the initializer is zero, the warning is omitted. This is done under the assumption that the zero initializer in user code appears conditioned on e.g. \f(CW\*(C`_\|_STDC_\|_\*(C'\fR to avoid missing initializer warnings and relies on default initialization to zero in the traditional C case. -.Ip "\(bu" 4 +.IP "*" 4 Conversions by prototypes between fixed/floating point values and vice versa. The absence of these prototypes when compiling with traditional C would cause serious problems. This is a subset of the possible conversion warnings, for the full set use \fB\-Wconversion\fR. +.IP "*" 4 +Use of \s-1ISO\s0 C style function definitions. This warning intentionally is +\&\fInot\fR issued for prototype declarations or variadic functions +because these \s-1ISO\s0 C features will appear in your code when using +libiberty's traditional C compatibility macros, \f(CW\*(C`PARAMS\*(C'\fR and +\&\f(CW\*(C`VPARAMS\*(C'\fR. This warning is also bypassed for nested functions +because that feature is already a \s-1GCC\s0 extension and thus not relevant to +traditional C compatibility. .RE .RS 4 .RE -.Ip "\fB\-Wundef\fR" 4 +.IP "\fB\-Wdeclaration\-after\-statement\fR (C only)" 4 +.IX Item "-Wdeclaration-after-statement (C only)" +Warn when a declaration is found after a statement in a block. This +construct, known from \*(C+, was introduced with \s-1ISO\s0 C99 and is by default +allowed in \s-1GCC\s0. It is not supported by \s-1ISO\s0 C90 and was not supported by +\&\s-1GCC\s0 versions before \s-1GCC\s0 3.0. +.IP "\fB\-Wundef\fR" 4 .IX Item "-Wundef" Warn if an undefined identifier is evaluated in an \fB#if\fR directive. -.Ip "\fB\-Wshadow\fR" 4 +.IP "\fB\-Wendif\-labels\fR" 4 +.IX Item "-Wendif-labels" +Warn whenever an \fB#else\fR or an \fB#endif\fR are followed by text. +.IP "\fB\-Wshadow\fR" 4 .IX Item "-Wshadow" Warn whenever a local variable shadows another local variable, parameter or global variable or whenever a built-in function is shadowed. -.Ip "\fB\-Wlarger-than-\fR\fIlen\fR" 4 +.IP "\fB\-Wlarger\-than\-\fR\fIlen\fR" 4 .IX Item "-Wlarger-than-len" Warn whenever an object of larger than \fIlen\fR bytes is defined. -.Ip "\fB\-Wpointer-arith\fR" 4 +.IP "\fB\-Wpointer\-arith\fR" 4 .IX Item "-Wpointer-arith" Warn about anything that depends on the ``size of'' a function type or of \f(CW\*(C`void\*(C'\fR. \s-1GNU\s0 C assigns these types a size of 1, for convenience in calculations with \f(CW\*(C`void *\*(C'\fR pointers and pointers to functions. -.Ip "\fB\-Wbad-function-cast\fR (C only)" 4 +.IP "\fB\-Wbad\-function\-cast\fR (C only)" 4 .IX Item "-Wbad-function-cast (C only)" Warn whenever a function call is cast to a non-matching type. For example, warn if \f(CW\*(C`int malloc()\*(C'\fR is cast to \f(CW\*(C`anything *\*(C'\fR. -.Ip "\fB\-Wcast-qual\fR" 4 +.IP "\fB\-Wcast\-qual\fR" 4 .IX Item "-Wcast-qual" Warn whenever a pointer is cast so as to remove a type qualifier from the target type. For example, warn if a \f(CW\*(C`const char *\*(C'\fR is cast to an ordinary \f(CW\*(C`char *\*(C'\fR. -.Ip "\fB\-Wcast-align\fR" 4 +.IP "\fB\-Wcast\-align\fR" 4 .IX Item "-Wcast-align" Warn whenever a pointer is cast such that the required alignment of the target is increased. For example, warn if a \f(CW\*(C`char *\*(C'\fR is cast to an \f(CW\*(C`int *\*(C'\fR on machines where integers can only be accessed at -two- or four-byte boundaries. -.Ip "\fB\-Wwrite-strings\fR" 4 +two\- or four-byte boundaries. +.IP "\fB\-Wwrite\-strings\fR" 4 .IX Item "-Wwrite-strings" When compiling C, give string constants the type \f(CW\*(C`const char[\f(CIlength\f(CW]\*(C'\fR so that -copying the address of one into a non-\f(CW\*(C`const\*(C'\fR \f(CW\*(C`char *\*(C'\fR +copying the address of one into a non\-\f(CW\*(C`const\*(C'\fR \f(CW\*(C`char *\*(C'\fR pointer will get a warning; when compiling \*(C+, warn about the deprecated conversion from string constants to \f(CW\*(C`char *\*(C'\fR. These warnings will help you find at @@ -2290,7 +2522,7 @@ compile time code that can try to write into a string constant, but only if you have been very careful about using \f(CW\*(C`const\*(C'\fR in declarations and prototypes. Otherwise, it will just be a nuisance; this is why we did not make \fB\-Wall\fR request these warnings. -.Ip "\fB\-Wconversion\fR" 4 +.IP "\fB\-Wconversion\fR" 4 .IX Item "-Wconversion" Warn if a prototype causes a type conversion that is different from what would happen to the same argument in the absence of a prototype. This @@ -2302,36 +2534,40 @@ Also, warn if a negative integer constant expression is implicitly converted to an unsigned type. For example, warn about the assignment \&\f(CW\*(C`x = \-1\*(C'\fR if \f(CW\*(C`x\*(C'\fR is unsigned. But do not warn about explicit casts like \f(CW\*(C`(unsigned) \-1\*(C'\fR. -.Ip "\fB\-Wsign-compare\fR" 4 +.IP "\fB\-Wsign\-compare\fR" 4 .IX Item "-Wsign-compare" Warn when a comparison between signed and unsigned values could produce an incorrect result when the signed value is converted to unsigned. -This warning is also enabled by \fB\-W\fR; to get the other warnings -of \fB\-W\fR without this warning, use \fB\-W \-Wno-sign-compare\fR. -.Ip "\fB\-Waggregate-return\fR" 4 +This warning is also enabled by \fB\-Wextra\fR; to get the other warnings +of \fB\-Wextra\fR without this warning, use \fB\-Wextra \-Wno\-sign\-compare\fR. +.IP "\fB\-Waggregate\-return\fR" 4 .IX Item "-Waggregate-return" Warn if any functions that return structures or unions are defined or called. (In languages where you can return an array, this also elicits a warning.) -.Ip "\fB\-Wstrict-prototypes\fR (C only)" 4 +.IP "\fB\-Wstrict\-prototypes\fR (C only)" 4 .IX Item "-Wstrict-prototypes (C only)" Warn if a function is declared or defined without specifying the argument types. (An old-style function definition is permitted without a warning if preceded by a declaration which specifies the argument types.) -.Ip "\fB\-Wmissing-prototypes\fR (C only)" 4 +.IP "\fB\-Wold\-style\-definition\fR (C only)" 4 +.IX Item "-Wold-style-definition (C only)" +Warn if an old-style function definition is used. A warning is given +even if there is a previous prototype. +.IP "\fB\-Wmissing\-prototypes\fR (C only)" 4 .IX Item "-Wmissing-prototypes (C only)" Warn if a global function is defined without a previous prototype declaration. This warning is issued even if the definition itself provides a prototype. The aim is to detect global functions that fail to be declared in header files. -.Ip "\fB\-Wmissing-declarations\fR" 4 -.IX Item "-Wmissing-declarations" +.IP "\fB\-Wmissing\-declarations\fR (C only)" 4 +.IX Item "-Wmissing-declarations (C only)" Warn if a global function is defined without a previous declaration. Do so even if the definition itself provides a prototype. Use this option to detect global functions that are not declared in header files. -.Ip "\fB\-Wmissing-noreturn\fR" 4 +.IP "\fB\-Wmissing\-noreturn\fR" 4 .IX Item "-Wmissing-noreturn" Warn about functions which might be candidates for attribute \f(CW\*(C`noreturn\*(C'\fR. Note these are only possible candidates, not absolute ones. Care should @@ -2339,7 +2575,7 @@ be taken to manually verify functions actually do not ever return before adding the \f(CW\*(C`noreturn\*(C'\fR attribute, otherwise subtle code generation bugs could be introduced. You will not get a warning for \f(CW\*(C`main\*(C'\fR in hosted C environments. -.Ip "\fB\-Wmissing-format-attribute\fR" 4 +.IP "\fB\-Wmissing\-format\-attribute\fR" 4 .IX Item "-Wmissing-format-attribute" If \fB\-Wformat\fR is enabled, also warn about functions which might be candidates for \f(CW\*(C`format\*(C'\fR attributes. Note these are only possible @@ -2349,13 +2585,18 @@ like \f(CW\*(C`vprintf\*(C'\fR or \f(CW\*(C`vscanf\*(C'\fR, but this might not a case, and some functions for which \f(CW\*(C`format\*(C'\fR attributes are appropriate may not be detected. This option has no effect unless \&\fB\-Wformat\fR is enabled (possibly by \fB\-Wall\fR). -.Ip "\fB\-Wno-deprecated-declarations\fR" 4 +.IP "\fB\-Wno\-multichar\fR" 4 +.IX Item "-Wno-multichar" +Do not warn if a multicharacter constant (\fB'\s-1FOOF\s0'\fR) is used. +Usually they indicate a typo in the user's code, as they have +implementation-defined values, and should not be used in portable code. +.IP "\fB\-Wno\-deprecated\-declarations\fR" 4 .IX Item "-Wno-deprecated-declarations" Do not warn about uses of functions, variables, and types marked as deprecated by using the \f(CW\*(C`deprecated\*(C'\fR attribute. (@pxref{Function Attributes}, \f(CW@pxref\fR{Variable Attributes}, \&\f(CW@pxref\fR{Type Attributes}.) -.Ip "\fB\-Wpacked\fR" 4 +.IP "\fB\-Wpacked\fR" 4 .IX Item "-Wpacked" Warn if a structure is given the packed attribute, but the packed attribute has no effect on the layout or size of the structure. @@ -2374,20 +2615,20 @@ have the packed attribute: \& struct foo f; \& }; .Ve -.Ip "\fB\-Wpadded\fR" 4 +.IP "\fB\-Wpadded\fR" 4 .IX Item "-Wpadded" Warn if padding is included in a structure, either to align an element of the structure or to align the whole structure. Sometimes when this happens it is possible to rearrange the fields of the structure to reduce the padding and so make the structure smaller. -.Ip "\fB\-Wredundant-decls\fR" 4 +.IP "\fB\-Wredundant\-decls\fR" 4 .IX Item "-Wredundant-decls" Warn if anything is declared more than once in the same scope, even in cases where multiple declaration is valid and changes nothing. -.Ip "\fB\-Wnested-externs\fR (C only)" 4 +.IP "\fB\-Wnested\-externs\fR (C only)" 4 .IX Item "-Wnested-externs (C only)" Warn if an \f(CW\*(C`extern\*(C'\fR declaration is encountered within a function. -.Ip "\fB\-Wunreachable-code\fR" 4 +.IP "\fB\-Wunreachable\-code\fR" 4 .IX Item "-Wunreachable-code" Warn if the compiler detects that code will never be executed. .Sp @@ -2407,17 +2648,44 @@ This option is not made part of \fB\-Wall\fR because in a debugging version of a program there is often substantial code which checks correct functioning of the program and is, hopefully, unreachable because the program does work. Another common use of unreachable -code is to provide behavior which is selectable at compile-time. -.Ip "\fB\-Winline\fR" 4 +code is to provide behavior which is selectable at compile\-time. +.IP "\fB\-Winline\fR" 4 .IX Item "-Winline" Warn if a function can not be inlined and it was declared as inline. -.Ip "\fB\-Wlong-long\fR" 4 +Even with this option, the compiler will not warn about failures to +inline functions declared in system headers. +.Sp +The compiler uses a variety of heuristics to determine whether or not +to inline a function. For example, the compiler takes into account +the size of the function being inlined and the the amount of inlining +that has already been done in the current function. Therefore, +seemingly insignificant changes in the source program can cause the +warnings produced by \fB\-Winline\fR to appear or disappear. +.IP "\fB\-Wno\-invalid\-offsetof\fR (\*(C+ only)" 4 +.IX Item "-Wno-invalid-offsetof ( only)" +Suppress warnings from applying the \fBoffsetof\fR macro to a non-POD +type. According to the 1998 \s-1ISO\s0 \*(C+ standard, applying \fBoffsetof\fR +to a non-POD type is undefined. In existing \*(C+ implementations, +however, \fBoffsetof\fR typically gives meaningful results even when +applied to certain kinds of non-POD types. (Such as a simple +\&\fBstruct\fR that fails to be a \s-1POD\s0 type only by virtue of having a +constructor.) This flag is for users who are aware that they are +writing nonportable code and who have deliberately chosen to ignore the +warning about it. +.Sp +The restrictions on \fBoffsetof\fR may be relaxed in a future version +of the \*(C+ standard. +.IP "\fB\-Winvalid\-pch\fR" 4 +.IX Item "-Winvalid-pch" +Warn if a precompiled header is found in +the search path but can't be used. +.IP "\fB\-Wlong\-long\fR" 4 .IX Item "-Wlong-long" Warn if \fBlong long\fR type is used. This is default. To inhibit -the warning messages, use \fB\-Wno-long-long\fR. Flags -\&\fB\-Wlong-long\fR and \fB\-Wno-long-long\fR are taken into account +the warning messages, use \fB\-Wno\-long\-long\fR. Flags +\&\fB\-Wlong\-long\fR and \fB\-Wno\-long\-long\fR are taken into account only when \fB\-pedantic\fR flag is used. -.Ip "\fB\-Wdisabled-optimization\fR" 4 +.IP "\fB\-Wdisabled\-optimization\fR" 4 .IX Item "-Wdisabled-optimization" Warn if a requested optimization pass is disabled. This warning does not generally indicate that there is anything wrong with your code; it @@ -2425,14 +2693,14 @@ merely indicates that \s-1GCC\s0's optimizers were unable to handle the code effectively. Often, the problem is that your code is too big or too complex; \s-1GCC\s0 will refuse to optimize programs when the optimization itself is likely to take inordinate amounts of time. -.Ip "\fB\-Werror\fR" 4 +.IP "\fB\-Werror\fR" 4 .IX Item "-Werror" Make all warnings into errors. .Sh "Options for Debugging Your Program or \s-1GCC\s0" .IX Subsection "Options for Debugging Your Program or GCC" \&\s-1GCC\s0 has various special options that are used for debugging either your program or \s-1GCC:\s0 -.Ip "\fB\-g\fR" 4 +.IP "\fB\-g\fR" 4 .IX Item "-g" Produce debugging information in the operating system's native format (stabs, \s-1COFF\s0, \s-1XCOFF\s0, or \s-1DWARF\s0). \s-1GDB\s0 can work with this debugging @@ -2444,8 +2712,7 @@ makes debugging work better in \s-1GDB\s0 but will probably make other debuggers crash or refuse to read the program. If you want to control for certain whether to generate the extra information, use \fB\-gstabs+\fR, \fB\-gstabs\fR, -\&\fB\-gxcoff+\fR, \fB\-gxcoff\fR, \fB\-gdwarf-1+\fR, \fB\-gdwarf-1\fR, -or \fB\-gvms\fR (see below). +\&\fB\-gxcoff+\fR, \fB\-gxcoff\fR, or \fB\-gvms\fR (see below). .Sp Unlike most other C compilers, \s-1GCC\s0 allows you to use \fB\-g\fR with \&\fB\-O\fR. The shortcuts taken by optimized code may occasionally @@ -2460,72 +2727,65 @@ it reasonable to use the optimizer for programs that might have bugs. .Sp The following options are useful when \s-1GCC\s0 is generated with the capability for more than one debugging format. -.Ip "\fB\-ggdb\fR" 4 +.IP "\fB\-ggdb\fR" 4 .IX Item "-ggdb" Produce debugging information for use by \s-1GDB\s0. This means to use the most expressive format available (\s-1DWARF\s0 2, stabs, or the native format if neither of those are supported), including \s-1GDB\s0 extensions if at all possible. -.Ip "\fB\-gstabs\fR" 4 +.IP "\fB\-gstabs\fR" 4 .IX Item "-gstabs" Produce debugging information in stabs format (if that is supported), without \s-1GDB\s0 extensions. This is the format used by \s-1DBX\s0 on most \s-1BSD\s0 systems. On \s-1MIPS\s0, Alpha and System V Release 4 systems this option produces stabs debugging output which is not understood by \s-1DBX\s0 or \s-1SDB\s0. On System V Release 4 systems this option requires the \s-1GNU\s0 assembler. -.Ip "\fB\-gstabs+\fR" 4 +.IP "\fB\-feliminate\-unused\-debug\-symbols\fR" 4 +.IX Item "-feliminate-unused-debug-symbols" +Produce debugging information in stabs format (if that is supported), +for only symbols that are actually used. +.IP "\fB\-gstabs+\fR" 4 .IX Item "-gstabs+" Produce debugging information in stabs format (if that is supported), using \s-1GNU\s0 extensions understood only by the \s-1GNU\s0 debugger (\s-1GDB\s0). The use of these extensions is likely to make other debuggers crash or refuse to read the program. -.Ip "\fB\-gcoff\fR" 4 +.IP "\fB\-gcoff\fR" 4 .IX Item "-gcoff" Produce debugging information in \s-1COFF\s0 format (if that is supported). This is the format used by \s-1SDB\s0 on most System V systems prior to System V Release 4. -.Ip "\fB\-gxcoff\fR" 4 +.IP "\fB\-gxcoff\fR" 4 .IX Item "-gxcoff" Produce debugging information in \s-1XCOFF\s0 format (if that is supported). This is the format used by the \s-1DBX\s0 debugger on \s-1IBM\s0 \s-1RS/6000\s0 systems. -.Ip "\fB\-gxcoff+\fR" 4 +.IP "\fB\-gxcoff+\fR" 4 .IX Item "-gxcoff+" Produce debugging information in \s-1XCOFF\s0 format (if that is supported), using \s-1GNU\s0 extensions understood only by the \s-1GNU\s0 debugger (\s-1GDB\s0). The use of these extensions is likely to make other debuggers crash or refuse to read the program, and may cause assemblers other than the \s-1GNU\s0 assembler (\s-1GAS\s0) to fail with an error. -.Ip "\fB\-gdwarf\fR" 4 -.IX Item "-gdwarf" -Produce debugging information in \s-1DWARF\s0 version 1 format (if that is -supported). This is the format used by \s-1SDB\s0 on most System V Release 4 -systems. -.Ip "\fB\-gdwarf+\fR" 4 -.IX Item "-gdwarf+" -Produce debugging information in \s-1DWARF\s0 version 1 format (if that is -supported), using \s-1GNU\s0 extensions understood only by the \s-1GNU\s0 debugger -(\s-1GDB\s0). The use of these extensions is likely to make other debuggers -crash or refuse to read the program. -.Ip "\fB\-gdwarf-2\fR" 4 +.IP "\fB\-gdwarf\-2\fR" 4 .IX Item "-gdwarf-2" Produce debugging information in \s-1DWARF\s0 version 2 format (if that is supported). This is the format used by \s-1DBX\s0 on \s-1IRIX\s0 6. -.Ip "\fB\-gvms\fR" 4 +.IP "\fB\-gvms\fR" 4 .IX Item "-gvms" Produce debugging information in \s-1VMS\s0 debug format (if that is supported). This is the format used by \s-1DEBUG\s0 on \s-1VMS\s0 systems. -.Ip "\fB\-g\fR\fIlevel\fR" 4 +.IP "\fB\-g\fR\fIlevel\fR" 4 .IX Item "-glevel" .PD 0 -.Ip "\fB\-ggdb\fR\fIlevel\fR" 4 +.IP "\fB\-ggdb\fR\fIlevel\fR" 4 .IX Item "-ggdblevel" -.Ip "\fB\-gstabs\fR\fIlevel\fR" 4 +.IP "\fB\-gstabs\fR\fIlevel\fR" 4 .IX Item "-gstabslevel" -.Ip "\fB\-gcoff\fR\fIlevel\fR" 4 +.IP "\fB\-gcoff\fR\fIlevel\fR" 4 .IX Item "-gcofflevel" -.Ip "\fB\-gxcoff\fR\fIlevel\fR" 4 +.IP "\fB\-gxcoff\fR\fIlevel\fR" 4 .IX Item "-gxcofflevel" -.Ip "\fB\-gvms\fR\fIlevel\fR" 4 +.IP "\fB\-gvms\fR\fIlevel\fR" 4 .IX Item "-gvmslevel" .PD Request debugging information and also use \fIlevel\fR to specify how @@ -2541,305 +2801,340 @@ present in the program. Some debuggers support macro expansion when you use \fB\-g3\fR. .Sp Note that in order to avoid confusion between \s-1DWARF1\s0 debug level 2, -and \s-1DWARF2\s0, neither \fB\-gdwarf\fR nor \fB\-gdwarf-2\fR accept -a concatenated debug level. Instead use an additional \fB\-g\fR\fIlevel\fR -option to change the debug level for \s-1DWARF1\s0 or \s-1DWARF2\s0. -.Ip "\fB\-p\fR" 4 +and \s-1DWARF2\s0 \fB\-gdwarf\-2\fR does not accept a concatenated debug +level. Instead use an additional \fB\-g\fR\fIlevel\fR option to +change the debug level for \s-1DWARF2\s0. +.IP "\fB\-feliminate\-dwarf2\-dups\fR" 4 +.IX Item "-feliminate-dwarf2-dups" +Compress \s-1DWARF2\s0 debugging information by eliminating duplicated +information about each symbol. This option only makes sense when +generating \s-1DWARF2\s0 debugging information with \fB\-gdwarf\-2\fR. +.IP "\fB\-p\fR" 4 .IX Item "-p" Generate extra code to write profile information suitable for the -analysis program \f(CW\*(C`prof\*(C'\fR. You must use this option when compiling +analysis program \fBprof\fR. You must use this option when compiling the source files you want data about, and you must also use it when linking. -.Ip "\fB\-pg\fR" 4 +.IP "\fB\-pg\fR" 4 .IX Item "-pg" Generate extra code to write profile information suitable for the -analysis program \f(CW\*(C`gprof\*(C'\fR. You must use this option when compiling +analysis program \fBgprof\fR. You must use this option when compiling the source files you want data about, and you must also use it when linking. -.Ip "\fB\-Q\fR" 4 +.IP "\fB\-Q\fR" 4 .IX Item "-Q" Makes the compiler print out each function name as it is compiled, and print some statistics about each pass when it finishes. -.Ip "\fB\-ftime-report\fR" 4 +.IP "\fB\-ftime\-report\fR" 4 .IX Item "-ftime-report" Makes the compiler print some statistics about the time consumed by each pass when it finishes. -.Ip "\fB\-fmem-report\fR" 4 +.IP "\fB\-fmem\-report\fR" 4 .IX Item "-fmem-report" Makes the compiler print some statistics about permanent memory allocation when it finishes. -.Ip "\fB\-fprofile-arcs\fR" 4 +.IP "\fB\-fprofile\-arcs\fR" 4 .IX Item "-fprofile-arcs" -Instrument \fIarcs\fR during compilation to generate coverage data -or for profile-directed block ordering. During execution the program -records how many times each branch is executed and how many times it is -taken. When the compiled program exits it saves this data to a file -called \fI\fIsourcename\fI.da\fR for each source file. -.Sp -For profile-directed block ordering, compile the program with -\&\fB\-fprofile-arcs\fR plus optimization and code generation options, -generate the arc profile information by running the program on a -selected workload, and then compile the program again with the same -optimization and code generation options plus -\&\fB\-fbranch-probabilities\fR. -.Sp -The other use of \fB\-fprofile-arcs\fR is for use with \f(CW\*(C`gcov\*(C'\fR, -when it is used with the \fB\-ftest-coverage\fR option. -.Sp -With \fB\-fprofile-arcs\fR, for each function of your program \s-1GCC\s0 +Add code so that program flow \fIarcs\fR are instrumented. During +execution the program records how many times each branch and call is +executed and how many times it is taken or returns. When the compiled +program exits it saves this data to a file called +\&\fI\fIauxname\fI.gcda\fR for each source file. The data may be used for +profile-directed optimizations (\fB\-fbranch\-probabilities\fR), or for +test coverage analysis (\fB\-ftest\-coverage\fR). Each object file's +\&\fIauxname\fR is generated from the name of the output file, if +explicitly specified and it is not the final executable, otherwise it is +the basename of the source file. In both cases any suffix is removed +(e.g. \fIfoo.gcda\fR for input file \fIdir/foo.c\fR, or +\&\fIdir/foo.gcda\fR for output file specified as \fB\-o dir/foo.o\fR). +.RS 4 +.IP "@bullet" 4 +.IX Item "@bullet" +Compile the source files with \fB\-fprofile\-arcs\fR plus optimization +and code generation options. For test coverage analysis, use the +additional \fB\-ftest\-coverage\fR option. You do not need to profile +every source file in a program. +.IP "@cvmmfu" 4 +.IX Item "@cvmmfu" +Link your object files with \fB\-lgcov\fR or \fB\-fprofile\-arcs\fR +(the latter implies the former). +.IP "@dwnngv" 4 +.IX Item "@dwnngv" +Run the program on a representative workload to generate the arc profile +information. This may be repeated any number of times. You can run +concurrent instances of your program, and provided that the file system +supports locking, the data files will be correctly updated. Also +\&\f(CW\*(C`fork\*(C'\fR calls are detected and correctly handled (double counting +will not happen). +.IP "@exoohw" 4 +.IX Item "@exoohw" +For profile-directed optimizations, compile the source files again with +the same optimization and code generation options plus +\&\fB\-fbranch\-probabilities\fR. +.IP "@fyppix" 4 +.IX Item "@fyppix" +For test coverage analysis, use \fBgcov\fR to produce human readable +information from the \fI.gcno\fR and \fI.gcda\fR files. Refer to the +\&\fBgcov\fR documentation for further information. +.RE +.RS 4 +.Sp +With \fB\-fprofile\-arcs\fR, for each function of your program \s-1GCC\s0 creates a program flow graph, then finds a spanning tree for the graph. Only arcs that are not on the spanning tree have to be instrumented: the compiler adds code to count the number of times that these arcs are executed. When an arc is the only exit or only entrance to a block, the instrumentation code can be added to the block; otherwise, a new basic block must be created to hold the instrumentation code. -.Ip "\fB\-ftest-coverage\fR" 4 -.IX Item "-ftest-coverage" -Create data files for the \fBgcov\fR code-coverage utility. -The data file names begin with the name of your source file: -.RS 4 -.Ip "\fIsourcename\fR\fB.bb\fR" 4 -.IX Item "sourcename.bb" -A mapping from basic blocks to line numbers, which \f(CW\*(C`gcov\*(C'\fR uses to -associate basic block execution counts with line numbers. -.Ip "\fIsourcename\fR\fB.bbg\fR" 4 -.IX Item "sourcename.bbg" -A list of all arcs in the program flow graph. This allows \f(CW\*(C`gcov\*(C'\fR -to reconstruct the program flow graph, so that it can compute all basic -block and arc execution counts from the information in the -\&\f(CW\*(C`\f(CIsourcename\f(CW.da\*(C'\fR file. -.RE -.RS 4 -.Sp -Use \fB\-ftest-coverage\fR with \fB\-fprofile-arcs\fR; the latter -option adds instrumentation to the program, which then writes -execution counts to another data file: -.RS 4 -.RE -.Ip "\fIsourcename\fR\fB.da\fR" 4 -.IX Item "sourcename.da" -Runtime arc execution counts, used in conjunction with the arc -information in the file \f(CW\*(C`\f(CIsourcename\f(CW.bbg\*(C'\fR. -.RE -.RS 4 -.Sp -Coverage data will map better to the source files if -\&\fB\-ftest-coverage\fR is used without optimization. .RE -.Ip "\fB\-d\fR\fIletters\fR" 4 +.IP "\fB\-ftest\-coverage\fR" 4 +.IX Item "-ftest-coverage" +Produce a notes file that the \fBgcov\fR code-coverage utility can use to +show program coverage. Each source file's note file is called +\&\fI\fIauxname\fI.gcno\fR. Refer to the \fB\-fprofile\-arcs\fR option +above for a description of \fIauxname\fR and instructions on how to +generate test coverage data. Coverage data will match the source files +more closely, if you do not optimize. +.IP "\fB\-d\fR\fIletters\fR" 4 .IX Item "-dletters" Says to make debugging dumps during compilation at times specified by \&\fIletters\fR. This is used for debugging the compiler. The file names for most of the dumps are made by appending a pass number and a word to -the source file name (e.g. \fIfoo.c.00.rtl\fR or \fIfoo.c.01.sibling\fR). -Here are the possible letters for use in \fIletters\fR, and their meanings: +the \fIdumpname\fR. \fIdumpname\fR is generated from the name of the +output file, if explicitly specified and it is not an executable, +otherwise it is the basename of the source file. In both cases any +suffix is removed (e.g. \fIfoo.01.rtl\fR or \fIfoo.02.sibling\fR). +Here are the possible letters for use in \fIletters\fR, and their +meanings: .RS 4 -.Ip "\fBA\fR" 4 +.IP "\fBA\fR" 4 .IX Item "A" Annotate the assembler output with miscellaneous debugging information. -.Ip "\fBb\fR" 4 +.IP "\fBb\fR" 4 .IX Item "b" -Dump after computing branch probabilities, to \fI\fIfile\fI.14.bp\fR. -.Ip "\fBB\fR" 4 +Dump after computing branch probabilities, to \fI\fIfile\fI.12.bp\fR. +.IP "\fBB\fR" 4 .IX Item "B" -Dump after block reordering, to \fI\fIfile\fI.29.bbro\fR. -.Ip "\fBc\fR" 4 +Dump after block reordering, to \fI\fIfile\fI.31.bbro\fR. +.IP "\fBc\fR" 4 .IX Item "c" -Dump after instruction combination, to the file \fI\fIfile\fI.16.combine\fR. -.Ip "\fBC\fR" 4 +Dump after instruction combination, to the file \fI\fIfile\fI.20.combine\fR. +.IP "\fBC\fR" 4 .IX Item "C" -Dump after the first if conversion, to the file \fI\fIfile\fI.17.ce\fR. -.Ip "\fBd\fR" 4 +Dump after the first if conversion, to the file \fI\fIfile\fI.14.ce1\fR. +Also dump after the second if conversion, to the file \fI\fIfile\fI.21.ce2\fR. +.IP "\fBd\fR" 4 .IX Item "d" -Dump after delayed branch scheduling, to \fI\fIfile\fI.31.dbr\fR. -.Ip "\fBD\fR" 4 +Dump after branch target load optimization, to to \fI\fIfile\fI.32.btl\fR. +Also dump after delayed branch scheduling, to \fI\fIfile\fI.36.dbr\fR. +.IP "\fBD\fR" 4 .IX Item "D" Dump all macro definitions, at the end of preprocessing, in addition to normal output. -.Ip "\fBe\fR" 4 -.IX Item "e" -Dump after \s-1SSA\s0 optimizations, to \fI\fIfile\fI.04.ssa\fR and -\&\fI\fIfile\fI.07.ussa\fR. -.Ip "\fBE\fR" 4 +.IP "\fBE\fR" 4 .IX Item "E" -Dump after the second if conversion, to \fI\fIfile\fI.26.ce2\fR. -.Ip "\fBf\fR" 4 +Dump after the third if conversion, to \fI\fIfile\fI.30.ce3\fR. +.IP "\fBf\fR" 4 .IX Item "f" -Dump after life analysis, to \fI\fIfile\fI.15.life\fR. -.Ip "\fBF\fR" 4 +Dump after control and data flow analysis, to \fI\fIfile\fI.11.cfg\fR. +Also dump after life analysis, to \fI\fIfile\fI.19.life\fR. +.IP "\fBF\fR" 4 .IX Item "F" -Dump after purging \f(CW\*(C`ADDRESSOF\*(C'\fR codes, to \fI\fIfile\fI.09.addressof\fR. -.Ip "\fBg\fR" 4 +Dump after purging \f(CW\*(C`ADDRESSOF\*(C'\fR codes, to \fI\fIfile\fI.07.addressof\fR. +.IP "\fBg\fR" 4 .IX Item "g" -Dump after global register allocation, to \fI\fIfile\fI.21.greg\fR. -.Ip "\fBh\fR" 4 -.IX Item "h" -Dump after finalization of \s-1EH\s0 handling code, to \fI\fIfile\fI.02.eh\fR. -.Ip "\fBk\fR" 4 -.IX Item "k" -Dump after reg-to-stack conversion, to \fI\fIfile\fI.28.stack\fR. -.Ip "\fBo\fR" 4 -.IX Item "o" -Dump after post-reload optimizations, to \fI\fIfile\fI.22.postreload\fR. -.Ip "\fBG\fR" 4 +Dump after global register allocation, to \fI\fIfile\fI.25.greg\fR. +.IP "\fBG\fR" 4 .IX Item "G" -Dump after \s-1GCSE\s0, to \fI\fIfile\fI.10.gcse\fR. -.Ip "\fBi\fR" 4 +Dump after \s-1GCSE\s0, to \fI\fIfile\fI.08.gcse\fR. +Also dump after jump bypassing and control flow optimizations, to +\&\fI\fIfile\fI.10.bypass\fR. +.IP "\fBh\fR" 4 +.IX Item "h" +Dump after finalization of \s-1EH\s0 handling code, to \fI\fIfile\fI.03.eh\fR. +.IP "\fBi\fR" 4 .IX Item "i" -Dump after sibling call optimizations, to \fI\fIfile\fI.01.sibling\fR. -.Ip "\fBj\fR" 4 +Dump after sibling call optimizations, to \fI\fIfile\fI.02.sibling\fR. +.IP "\fBj\fR" 4 .IX Item "j" -Dump after the first jump optimization, to \fI\fIfile\fI.03.jump\fR. -.Ip "\fBk\fR" 4 +Dump after the first jump optimization, to \fI\fIfile\fI.04.jump\fR. +.IP "\fBk\fR" 4 .IX Item "k" -Dump after conversion from registers to stack, to \fI\fIfile\fI.32.stack\fR. -.Ip "\fBl\fR" 4 +Dump after conversion from registers to stack, to \fI\fIfile\fI.34.stack\fR. +.IP "\fBl\fR" 4 .IX Item "l" -Dump after local register allocation, to \fI\fIfile\fI.20.lreg\fR. -.Ip "\fBL\fR" 4 +Dump after local register allocation, to \fI\fIfile\fI.24.lreg\fR. +.IP "\fBL\fR" 4 .IX Item "L" -Dump after loop optimization, to \fI\fIfile\fI.11.loop\fR. -.Ip "\fBM\fR" 4 +Dump after loop optimization passes, to \fI\fIfile\fI.09.loop\fR and +\&\fI\fIfile\fI.16.loop2\fR. +.IP "\fBM\fR" 4 .IX Item "M" -Dump after performing the machine dependent reorganisation pass, to -\&\fI\fIfile\fI.30.mach\fR. -.Ip "\fBn\fR" 4 +Dump after performing the machine dependent reorganization pass, to +\&\fI\fIfile\fI.35.mach\fR. +.IP "\fBn\fR" 4 .IX Item "n" -Dump after register renumbering, to \fI\fIfile\fI.25.rnreg\fR. -.Ip "\fBN\fR" 4 +Dump after register renumbering, to \fI\fIfile\fI.29.rnreg\fR. +.IP "\fBN\fR" 4 .IX Item "N" -Dump after the register move pass, to \fI\fIfile\fI.18.regmove\fR. -.Ip "\fBr\fR" 4 +Dump after the register move pass, to \fI\fIfile\fI.22.regmove\fR. +.IP "\fBo\fR" 4 +.IX Item "o" +Dump after post-reload optimizations, to \fI\fIfile\fI.26.postreload\fR. +.IP "\fBr\fR" 4 .IX Item "r" -Dump after \s-1RTL\s0 generation, to \fI\fIfile\fI.00.rtl\fR. -.Ip "\fBR\fR" 4 +Dump after \s-1RTL\s0 generation, to \fI\fIfile\fI.01.rtl\fR. +.IP "\fBR\fR" 4 .IX Item "R" -Dump after the second scheduling pass, to \fI\fIfile\fI.27.sched2\fR. -.Ip "\fBs\fR" 4 +Dump after the second scheduling pass, to \fI\fIfile\fI.33.sched2\fR. +.IP "\fBs\fR" 4 .IX Item "s" Dump after \s-1CSE\s0 (including the jump optimization that sometimes follows -\&\s-1CSE\s0), to \fI\fIfile\fI.08.cse\fR. -.Ip "\fBS\fR" 4 +\&\s-1CSE\s0), to \fI\fIfile\fI.06.cse\fR. +.IP "\fBS\fR" 4 .IX Item "S" -Dump after the first scheduling pass, to \fI\fIfile\fI.19.sched\fR. -.Ip "\fBt\fR" 4 +Dump after the first scheduling pass, to \fI\fIfile\fI.23.sched\fR. +.IP "\fBt\fR" 4 .IX Item "t" Dump after the second \s-1CSE\s0 pass (including the jump optimization that -sometimes follows \s-1CSE\s0), to \fI\fIfile\fI.12.cse2\fR. -.Ip "\fBw\fR" 4 +sometimes follows \s-1CSE\s0), to \fI\fIfile\fI.18.cse2\fR. +.IP "\fBT\fR" 4 +.IX Item "T" +Dump after running tracer, to \fI\fIfile\fI.15.tracer\fR. +.IP "\fBu\fR" 4 +.IX Item "u" +Dump after null pointer elimination pass to \fI\fIfile\fI.05.null\fR. +.IP "\fBU\fR" 4 +.IX Item "U" +Dump callgraph and unit-at-a-time optimization \fI\fIfile\fI.00.unit\fR. +.IP "\fBV\fR" 4 +.IX Item "V" +Dump after the value profile transformations, to \fI\fIfile\fI.13.vpt\fR. +.IP "\fBw\fR" 4 .IX Item "w" -Dump after the second flow pass, to \fI\fIfile\fI.23.flow2\fR. -.Ip "\fBX\fR" 4 -.IX Item "X" -Dump after \s-1SSA\s0 dead code elimination, to \fI\fIfile\fI.06.ssadce\fR. -.Ip "\fBz\fR" 4 +Dump after the second flow pass, to \fI\fIfile\fI.27.flow2\fR. +.IP "\fBz\fR" 4 .IX Item "z" -Dump after the peephole pass, to \fI\fIfile\fI.24.peephole2\fR. -.Ip "\fBa\fR" 4 +Dump after the peephole pass, to \fI\fIfile\fI.28.peephole2\fR. +.IP "\fBZ\fR" 4 +.IX Item "Z" +Dump after constructing the web, to \fI\fIfile\fI.17.web\fR. +.IP "\fBa\fR" 4 .IX Item "a" Produce all the dumps listed above. -.Ip "\fBm\fR" 4 +.IP "\fBH\fR" 4 +.IX Item "H" +Produce a core dump whenever an error occurs. +.IP "\fBm\fR" 4 .IX Item "m" Print statistics on memory usage, at the end of the run, to standard error. -.Ip "\fBp\fR" 4 +.IP "\fBp\fR" 4 .IX Item "p" Annotate the assembler output with a comment indicating which pattern and alternative was used. The length of each instruction is also printed. -.Ip "\fBP\fR" 4 +.IP "\fBP\fR" 4 .IX Item "P" Dump the \s-1RTL\s0 in the assembler output as a comment before each instruction. Also turns on \fB\-dp\fR annotation. -.Ip "\fBv\fR" 4 +.IP "\fBv\fR" 4 .IX Item "v" For each of the other indicated dump files (except for -\&\fI\fIfile\fI.00.rtl\fR), dump a representation of the control flow graph +\&\fI\fIfile\fI.01.rtl\fR), dump a representation of the control flow graph suitable for viewing with \s-1VCG\s0 to \fI\fIfile\fI.\fIpass\fI.vcg\fR. -.Ip "\fBx\fR" 4 +.IP "\fBx\fR" 4 .IX Item "x" Just generate \s-1RTL\s0 for a function instead of compiling it. Usually used with \fBr\fR. -.Ip "\fBy\fR" 4 +.IP "\fBy\fR" 4 .IX Item "y" Dump debugging information during parsing, to standard error. .RE .RS 4 .RE -.Ip "\fB\-fdump-unnumbered\fR" 4 +.IP "\fB\-fdump\-unnumbered\fR" 4 .IX Item "-fdump-unnumbered" When doing debugging dumps (see \fB\-d\fR option above), suppress instruction numbers and line number note output. This makes it more feasible to use diff on debugging dumps for compiler invocations with different options, in particular with and without \fB\-g\fR. -.Ip "\fB\-fdump-translation-unit\fR (C and \*(C+ only)" 4 +.IP "\fB\-fdump\-translation\-unit\fR (C and \*(C+ only)" 4 .IX Item "-fdump-translation-unit (C and only)" .PD 0 -.Ip "\fB\-fdump-translation-unit-\fR\fIoptions\fR\fB \fR(C and \*(C+ only)" 4 +.IP "\fB\-fdump\-translation\-unit\-\fR\fIoptions\fR\fB \fR(C and \*(C+ only)" 4 .IX Item "-fdump-translation-unit-options (C and only)" .PD Dump a representation of the tree structure for the entire translation unit to a file. The file name is made by appending \fI.tu\fR to the -source file name. If the \fB-\fR\fIoptions\fR form is used, \fIoptions\fR +source file name. If the \fB\-\fR\fIoptions\fR form is used, \fIoptions\fR controls the details of the dump as described for the -\&\fB\-fdump-tree\fR options. -.Ip "\fB\-fdump-class-hierarchy\fR (\*(C+ only)" 4 +\&\fB\-fdump\-tree\fR options. +.IP "\fB\-fdump\-class\-hierarchy\fR (\*(C+ only)" 4 .IX Item "-fdump-class-hierarchy ( only)" .PD 0 -.Ip "\fB\-fdump-class-hierarchy-\fR\fIoptions\fR\fB \fR(\*(C+ only)" 4 +.IP "\fB\-fdump\-class\-hierarchy\-\fR\fIoptions\fR\fB \fR(\*(C+ only)" 4 .IX Item "-fdump-class-hierarchy-options ( only)" .PD Dump a representation of each class's hierarchy and virtual function table layout to a file. The file name is made by appending \fI.class\fR -to the source file name. If the \fB-\fR\fIoptions\fR form is used, +to the source file name. If the \fB\-\fR\fIoptions\fR form is used, \&\fIoptions\fR controls the details of the dump as described for the -\&\fB\-fdump-tree\fR options. -.Ip "\fB\-fdump-tree-\fR\fIswitch\fR\fB \fR(\*(C+ only)" 4 +\&\fB\-fdump\-tree\fR options. +.IP "\fB\-fdump\-tree\-\fR\fIswitch\fR\fB \fR(\*(C+ only)" 4 .IX Item "-fdump-tree-switch ( only)" .PD 0 -.Ip "\fB\-fdump-tree-\fR\fIswitch\fR\fB-\fR\fIoptions\fR\fB \fR(\*(C+ only)" 4 +.IP "\fB\-fdump\-tree\-\fR\fIswitch\fR\fB\-\fR\fIoptions\fR\fB \fR(\*(C+ only)" 4 .IX Item "-fdump-tree-switch-options ( only)" .PD Control the dumping at various stages of processing the intermediate language tree to a file. The file name is generated by appending a switch -specific suffix to the source file name. If the \fB-\fR\fIoptions\fR -form is used, \fIoptions\fR is a list of \fB-\fR separated options that +specific suffix to the source file name. If the \fB\-\fR\fIoptions\fR +form is used, \fIoptions\fR is a list of \fB\-\fR separated options that control the details of the dump. Not all options are applicable to all dumps, those which are not meaningful will be ignored. The following options are available .RS 4 -.Ip "\fBaddress\fR" 4 +.IP "\fBaddress\fR" 4 .IX Item "address" Print the address of each node. Usually this is not meaningful as it changes according to the environment and source file. Its primary use is for tying up a dump file with a debug environment. -.Ip "\fBslim\fR" 4 +.IP "\fBslim\fR" 4 .IX Item "slim" Inhibit dumping of members of a scope or body of a function merely because that scope has been reached. Only dump such items when they are directly reachable by some other path. -.Ip "\fBall\fR" 4 +.IP "\fBall\fR" 4 .IX Item "all" Turn on all options. .RE .RS 4 .Sp The following tree dumps are possible: -.RS 4 -.RE -.Ip "\fBoriginal\fR" 4 +.IP "\fBoriginal\fR" 4 .IX Item "original" Dump before any tree based optimization, to \fI\fIfile\fI.original\fR. -.Ip "\fBoptimized\fR" 4 +.IP "\fBoptimized\fR" 4 .IX Item "optimized" Dump after all tree based optimization, to \fI\fIfile\fI.optimized\fR. -.Ip "\fBinlined\fR" 4 +.IP "\fBinlined\fR" 4 .IX Item "inlined" Dump after function inlining, to \fI\fIfile\fI.inlined\fR. .RE .RS 4 .RE -.Ip "\fB\-fsched-verbose=\fR\fIn\fR" 4 +.IP "\fB\-frandom\-seed=\fR\fIstring\fR" 4 +.IX Item "-frandom-seed=string" +This option provides a seed that \s-1GCC\s0 uses when it would otherwise use +random numbers. It is used to generate certain symbol names +that have to be different in every compiled file. It is also used to +place unique stamps in coverage data files and the object files that +produce them. You can use the \fB\-frandom\-seed\fR option to produce +reproducibly identical object files. +.Sp +The \fIstring\fR should be different for every file you compile. +.IP "\fB\-fsched\-verbose=\fR\fIn\fR" 4 .IX Item "-fsched-verbose=n" On targets that use instruction scheduling, this option controls the amount of debugging output the scheduler prints. This information is @@ -2849,28 +3144,21 @@ listing file, \fI.sched\fR or \fI.sched2\fR respectively. However for \fIn\fR greater than nine, the output is always printed to standard error. .Sp -For \fIn\fR greater than zero, \fB\-fsched-verbose\fR outputs the +For \fIn\fR greater than zero, \fB\-fsched\-verbose\fR outputs the same information as \fB\-dRS\fR. For \fIn\fR greater than one, it also output basic block probabilities, detailed ready list information and unit/insn info. For \fIn\fR greater than two, it includes \s-1RTL\s0 at abort point, control-flow and regions info. And for \fIn\fR over -four, \fB\-fsched-verbose\fR also includes dependence info. -.Ip "\fB\-fpretend-float\fR" 4 -.IX Item "-fpretend-float" -When running a cross-compiler, pretend that the target machine uses the -same floating point format as the host machine. This causes incorrect -output of the actual floating constants, but the actual instruction -sequence will probably be the same as \s-1GCC\s0 would make when running on -the target machine. -.Ip "\fB\-save-temps\fR" 4 +four, \fB\-fsched\-verbose\fR also includes dependence info. +.IP "\fB\-save\-temps\fR" 4 .IX Item "-save-temps" Store the usual ``temporary'' intermediate files permanently; place them in the current directory and name them based on the source file. Thus, -compiling \fIfoo.c\fR with \fB\-c \-save-temps\fR would produce files +compiling \fIfoo.c\fR with \fB\-c \-save\-temps\fR would produce files \&\fIfoo.i\fR and \fIfoo.s\fR, as well as \fIfoo.o\fR. This creates a preprocessed \fIfoo.i\fR output file even though the compiler now normally uses an integrated preprocessor. -.Ip "\fB\-time\fR" 4 +.IP "\fB\-time\fR" 4 .IX Item "-time" Report the \s-1CPU\s0 time taken by each subprocess in the compilation sequence. For C source files, this is the compiler proper and assembler @@ -2880,34 +3168,35 @@ sequence. For C source files, this is the compiler proper and assembler \& # cc1 0.12 0.01 \& # as 0.00 0.01 .Ve +.Sp The first number on each line is the ``user time,'' that is time spent executing the program itself. The second number is ``system time,'' time spent executing operating system routines on behalf of the program. Both numbers are in seconds. -.Ip "\fB\-print-file-name=\fR\fIlibrary\fR" 4 +.IP "\fB\-print\-file\-name=\fR\fIlibrary\fR" 4 .IX Item "-print-file-name=library" Print the full absolute name of the library file \fIlibrary\fR that would be used when linking\-\-\-and don't do anything else. With this option, \s-1GCC\s0 does not compile or link anything; it just prints the file name. -.Ip "\fB\-print-multi-directory\fR" 4 +.IP "\fB\-print\-multi\-directory\fR" 4 .IX Item "-print-multi-directory" Print the directory name corresponding to the multilib selected by any other switches present in the command line. This directory is supposed to exist in \fB\s-1GCC_EXEC_PREFIX\s0\fR. -.Ip "\fB\-print-multi-lib\fR" 4 +.IP "\fB\-print\-multi\-lib\fR" 4 .IX Item "-print-multi-lib" Print the mapping from multilib directory names to compiler switches that enable them. The directory name is separated from the switches by \&\fB;\fR, and each switch starts with an \fB@} instead of the -\&\f(CB@samp\fB{-\fR, without spaces between multiple switches. This is supposed to -ease shell-processing. -.Ip "\fB\-print-prog-name=\fR\fIprogram\fR" 4 +\&\f(CB@samp\fB{\-\fR, without spaces between multiple switches. This is supposed to +ease shell\-processing. +.IP "\fB\-print\-prog\-name=\fR\fIprogram\fR" 4 .IX Item "-print-prog-name=program" -Like \fB\-print-file-name\fR, but searches for a program such as \fBcpp\fR. -.Ip "\fB\-print-libgcc-file-name\fR" 4 +Like \fB\-print\-file\-name\fR, but searches for a program such as \fBcpp\fR. +.IP "\fB\-print\-libgcc\-file\-name\fR" 4 .IX Item "-print-libgcc-file-name" -Same as \fB\-print-file-name=libgcc.a\fR. +Same as \fB\-print\-file\-name=libgcc.a\fR. .Sp This is useful when you use \fB\-nostdlib\fR or \fB\-nodefaultlibs\fR but you do want to link with \fIlibgcc.a\fR. You can do @@ -2915,52 +3204,93 @@ but you do want to link with \fIlibgcc.a\fR. You can do .Vb 1 \& gcc -nostdlib <files>... `gcc -print-libgcc-file-name` .Ve -.Ip "\fB\-print-search-dirs\fR" 4 +.IP "\fB\-print\-search\-dirs\fR" 4 .IX Item "-print-search-dirs" Print the name of the configured installation directory and a list of -program and library directories gcc will search\-\-\-and don't do anything else. +program and library directories \fBgcc\fR will search\-\-\-and don't do anything else. .Sp -This is useful when gcc prints the error message +This is useful when \fBgcc\fR prints the error message \&\fBinstallation problem, cannot exec cpp0: No such file or directory\fR. To resolve this you either need to put \fIcpp0\fR and the other compiler -components where gcc expects to find them, or you can set the environment +components where \fBgcc\fR expects to find them, or you can set the environment variable \fB\s-1GCC_EXEC_PREFIX\s0\fR to the directory where you installed them. Don't forget the trailing '/'. -.Ip "\fB\-dumpmachine\fR" 4 +.IP "\fB\-dumpmachine\fR" 4 .IX Item "-dumpmachine" Print the compiler's target machine (for example, -\&\fBi686\-pc-linux-gnu\fR)\-\-\-and don't do anything else. -.Ip "\fB\-dumpversion\fR" 4 +\&\fBi686\-pc\-linux\-gnu\fR)\-\-\-and don't do anything else. +.IP "\fB\-dumpversion\fR" 4 .IX Item "-dumpversion" Print the compiler version (for example, \fB3.0\fR)\-\-\-and don't do anything else. -.Ip "\fB\-dumpspecs\fR" 4 +.IP "\fB\-dumpspecs\fR" 4 .IX Item "-dumpspecs" Print the compiler's built-in specs\-\-\-and don't do anything else. (This is used when \s-1GCC\s0 itself is being built.) +.IP "\fB\-feliminate\-unused\-debug\-types\fR" 4 +.IX Item "-feliminate-unused-debug-types" +Normally, when producing \s-1DWARF2\s0 output, \s-1GCC\s0 will emit debugging +information for all types declared in a compilation +unit, regardless of whether or not they are actually used +in that compilation unit. Sometimes this is useful, such as +if, in the debugger, you want to cast a value to a type that is +not actually used in your program (but is declared). More often, +however, this results in a significant amount of wasted space. +With this option, \s-1GCC\s0 will avoid producing debug symbol output +for types that are nowhere used in the source file being compiled. .Sh "Options That Control Optimization" .IX Subsection "Options That Control Optimization" -These options control various sorts of optimizations: -.Ip "\fB\-O\fR" 4 +These options control various sorts of optimizations. +.PP +Without any optimization option, the compiler's goal is to reduce the +cost of compilation and to make debugging produce the expected +results. Statements are independent: if you stop the program with a +breakpoint between statements, you can then assign a new value to any +variable or change the program counter to any other statement in the +function and get exactly the results you would expect from the source +code. +.PP +Turning on optimization flags makes the compiler attempt to improve +the performance and/or code size at the expense of compilation time +and possibly the ability to debug the program. +.PP +The compiler performs optimization based on the knowledge it has of +the program. Using the \fB\-funit\-at\-a\-time\fR flag will allow the +compiler to consider information gained from later functions in the +file when compiling a function. Compiling multiple files at once to a +single output file (and using \fB\-funit\-at\-a\-time\fR) will allow +the compiler to use information gained from all of the files when +compiling each of them. +.PP +Not all optimizations are controlled directly by a flag. Only +optimizations that have a flag are listed. +.IP "\fB\-O\fR" 4 .IX Item "-O" .PD 0 -.Ip "\fB\-O1\fR" 4 +.IP "\fB\-O1\fR" 4 .IX Item "-O1" .PD Optimize. Optimizing compilation takes somewhat more time, and a lot more memory for a large function. .Sp -Without \fB\-O\fR, the compiler's goal is to reduce the cost of -compilation and to make debugging produce the expected results. -Statements are independent: if you stop the program with a breakpoint -between statements, you can then assign a new value to any variable or -change the program counter to any other statement in the function and -get exactly the results you would expect from the source code. -.Sp With \fB\-O\fR, the compiler tries to reduce code size and execution time, without performing any optimizations that take a great deal of compilation time. -.Ip "\fB\-O2\fR" 4 +.Sp +\&\fB\-O\fR turns on the following optimization flags: +\&\fB\-fdefer\-pop +\&\-fmerge\-constants +\&\-fthread\-jumps +\&\-floop\-optimize +\&\-fif\-conversion +\&\-fif\-conversion2 +\&\-fdelayed\-branch +\&\-fguess\-branch\-probability +\&\-fcprop\-registers\fR +.Sp +\&\fB\-O\fR also turns on \fB\-fomit\-frame\-pointer\fR on machines +where doing so does not interfere with debugging. +.IP "\fB\-O2\fR" 4 .IX Item "-O2" Optimize even more. \s-1GCC\s0 performs nearly all supported optimizations that do not involve a space-speed tradeoff. The compiler does not @@ -2968,75 +3298,93 @@ perform loop unrolling or function inlining when you specify \fB\-O2\fR. As compared to \fB\-O\fR, this option increases both compilation time and the performance of the generated code. .Sp -\&\fB\-O2\fR turns on all optional optimizations except for loop unrolling, -function inlining, and register renaming. It also turns on the -\&\fB\-fforce-mem\fR option on all machines and frame pointer elimination -on machines where doing so does not interfere with debugging. +\&\fB\-O2\fR turns on all optimization flags specified by \fB\-O\fR. It +also turns on the following optimization flags: +\&\fB\-fforce\-mem +\&\-foptimize\-sibling\-calls +\&\-fstrength\-reduce +\&\-fcse\-follow\-jumps \-fcse\-skip\-blocks +\&\-frerun\-cse\-after\-loop \-frerun\-loop\-opt +\&\-fgcse \-fgcse\-lm \-fgcse\-sm \-fgcse\-las +\&\-fdelete\-null\-pointer\-checks +\&\-fexpensive\-optimizations +\&\-fregmove +\&\-fschedule\-insns \-fschedule\-insns2 +\&\-fsched\-interblock \-fsched\-spec +\&\-fcaller\-saves +\&\-fpeephole2 +\&\-freorder\-blocks \-freorder\-functions +\&\-fstrict\-aliasing +\&\-funit\-at\-a\-time +\&\-falign\-functions \-falign\-jumps +\&\-falign\-loops \-falign\-labels +\&\-fcrossjumping\fR .Sp Please note the warning under \fB\-fgcse\fR about invoking \fB\-O2\fR on programs that use computed gotos. -.Ip "\fB\-O3\fR" 4 +.IP "\fB\-O3\fR" 4 .IX Item "-O3" Optimize yet more. \fB\-O3\fR turns on all optimizations specified by -\&\fB\-O2\fR and also turns on the \fB\-finline-functions\fR and -\&\fB\-frename-registers\fR options. -.Ip "\fB\-O0\fR" 4 +\&\fB\-O2\fR and also turns on the \fB\-finline\-functions\fR, +\&\fB\-fweb\fR, \fB\-frename\-registers\fR and \fB\-funswitch\-loops\fR +options. +.IP "\fB\-O0\fR" 4 .IX Item "-O0" -Do not optimize. -.Ip "\fB\-Os\fR" 4 +Do not optimize. This is the default. +.IP "\fB\-Os\fR" 4 .IX Item "-Os" Optimize for size. \fB\-Os\fR enables all \fB\-O2\fR optimizations that do not typically increase code size. It also performs further optimizations designed to reduce code size. .Sp +\&\fB\-Os\fR disables the following optimization flags: +\&\fB\-falign\-functions \-falign\-jumps \-falign\-loops +\&\-falign\-labels \-freorder\-blocks \-fprefetch\-loop\-arrays\fR +.Sp If you use multiple \fB\-O\fR options, with or without level numbers, the last such option is the one that is effective. .PP Options of the form \fB\-f\fR\fIflag\fR specify machine-independent flags. Most flags have both positive and negative forms; the negative -form of \fB\-ffoo\fR would be \fB\-fno-foo\fR. In the table below, -only one of the forms is listed\-\-\-the one which is not the default. -You can figure out the other form by either removing \fBno-\fR or -adding it. -.Ip "\fB\-ffloat-store\fR" 4 -.IX Item "-ffloat-store" -Do not store floating point variables in registers, and inhibit other -options that might change whether a floating point value is taken from a -register or memory. -.Sp -This option prevents undesirable excess precision on machines such as -the 68000 where the floating registers (of the 68881) keep more -precision than a \f(CW\*(C`double\*(C'\fR is supposed to have. Similarly for the -x86 architecture. For most programs, the excess precision does only -good, but a few programs rely on the precise definition of \s-1IEEE\s0 floating -point. Use \fB\-ffloat-store\fR for such programs, after modifying -them to store all pertinent intermediate computations into variables. -.Ip "\fB\-fno-default-inline\fR" 4 +form of \fB\-ffoo\fR would be \fB\-fno\-foo\fR. In the table +below, only one of the forms is listed\-\-\-the one you typically will +use. You can figure out the other form by either removing \fBno\-\fR +or adding it. +.PP +The following options control specific optimizations. They are either +activated by \fB\-O\fR options or are related to ones that are. You +can use the following flags in the rare cases when ``fine\-tuning'' of +optimizations to be performed is desired. +.IP "\fB\-fno\-default\-inline\fR" 4 .IX Item "-fno-default-inline" Do not make member functions inline by default merely because they are defined inside the class scope (\*(C+ only). Otherwise, when you specify \&\fB\-O\fR, member functions defined inside class scope are compiled inline by default; i.e., you don't need to add \fBinline\fR in front of the member function name. -.Ip "\fB\-fno-defer-pop\fR" 4 +.IP "\fB\-fno\-defer\-pop\fR" 4 .IX Item "-fno-defer-pop" Always pop the arguments to each function call as soon as that function returns. For machines which must pop arguments after a function call, the compiler normally lets arguments accumulate on the stack for several function calls and pops them all at once. -.Ip "\fB\-fforce-mem\fR" 4 +.Sp +Disabled at levels \fB\-O\fR, \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-fforce\-mem\fR" 4 .IX Item "-fforce-mem" Force memory operands to be copied into registers before doing arithmetic on them. This produces better code by making all memory references potential common subexpressions. When they are not common subexpressions, instruction combination should eliminate the separate -register-load. The \fB\-O2\fR option turns on this option. -.Ip "\fB\-fforce-addr\fR" 4 +register\-load. +.Sp +Enabled at levels \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-fforce\-addr\fR" 4 .IX Item "-fforce-addr" Force memory address constants to be copied into registers before doing arithmetic on them. This may produce better code just as -\&\fB\-fforce-mem\fR may. -.Ip "\fB\-fomit-frame-pointer\fR" 4 +\&\fB\-fforce\-mem\fR may. +.IP "\fB\-fomit\-frame\-pointer\fR" 4 .IX Item "-fomit-frame-pointer" Don't keep the frame pointer in a register for functions that don't need one. This avoids the instructions to save, set up and @@ -3049,19 +3397,19 @@ the standard calling sequence automatically handles the frame pointer and nothing is saved by pretending it doesn't exist. The machine-description macro \f(CW\*(C`FRAME_POINTER_REQUIRED\*(C'\fR controls whether a target machine supports this flag. -.Ip "\fB\-foptimize-sibling-calls\fR" 4 +.Sp +Enabled at levels \fB\-O\fR, \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-foptimize\-sibling\-calls\fR" 4 .IX Item "-foptimize-sibling-calls" Optimize sibling and tail recursive calls. -.Ip "\fB\-ftrapv\fR" 4 -.IX Item "-ftrapv" -This option generates traps for signed overflow on addition, subtraction, -multiplication operations. -.Ip "\fB\-fno-inline\fR" 4 +.Sp +Enabled at levels \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-fno\-inline\fR" 4 .IX Item "-fno-inline" Don't pay attention to the \f(CW\*(C`inline\*(C'\fR keyword. Normally this option is used to keep the compiler from expanding any functions inline. Note that if you are not optimizing, no functions can be expanded inline. -.Ip "\fB\-finline-functions\fR" 4 +.IP "\fB\-finline\-functions\fR" 4 .IX Item "-finline-functions" Integrate all simple functions into their callers. The compiler heuristically decides which functions are simple enough to be worth @@ -3070,11 +3418,13 @@ integrating in this way. If all calls to a given function are integrated, and the function is declared \f(CW\*(C`static\*(C'\fR, then the function is normally not output as assembler code in its own right. -.Ip "\fB\-finline-limit=\fR\fIn\fR" 4 +.Sp +Enabled at level \fB\-O3\fR. +.IP "\fB\-finline\-limit=\fR\fIn\fR" 4 .IX Item "-finline-limit=n" -By default, gcc limits the size of functions that can be inlined. This flag +By default, \s-1GCC\s0 limits the size of functions that can be inlined. This flag allows the control of this limit for functions that are explicitly marked as -inline (ie marked with the inline keyword or defined within the class +inline (i.e., marked with the inline keyword or defined within the class definition in c++). \fIn\fR is the size of functions that can be inlined in number of pseudo instructions (not counting parameter handling). The default value of \fIn\fR is 600. @@ -3084,49 +3434,83 @@ the compilation faster and less code will be inlined (which presumably means slower programs). This option is particularly useful for programs that use inlining heavily such as those based on recursive templates with \*(C+. .Sp +Inlining is actually controlled by a number of parameters, which may be +specified individually by using \fB\-\-param\fR \fIname\fR\fB=\fR\fIvalue\fR. +The \fB\-finline\-limit=\fR\fIn\fR option sets some of these parameters +as follows: +.RS 4 +.Sp +.Vb 8 +\& @item max-inline-insns-single +\& is set to I<n>/2. +\& @item max-inline-insns-auto +\& is set to I<n>/2. +\& @item min-inline-insns +\& is set to 130 or I<n>/4, whichever is smaller. +\& @item max-inline-insns-rtl +\& is set to I<n>. +.Ve +.RE +.RS 4 +.Sp +See below for a documentation of the individual +parameters controlling inlining. +.Sp \&\fINote:\fR pseudo instruction represents, in this particular context, an abstract measurement of function's size. In no way, it represents a count of assembly instructions and as such its exact meaning might change from one release to an another. -.Ip "\fB\-fkeep-inline-functions\fR" 4 +.RE +.IP "\fB\-fkeep\-inline\-functions\fR" 4 .IX Item "-fkeep-inline-functions" Even if all calls to a given function are integrated, and the function is declared \f(CW\*(C`static\*(C'\fR, nevertheless output a separate run-time callable version of the function. This switch does not affect \&\f(CW\*(C`extern inline\*(C'\fR functions. -.Ip "\fB\-fkeep-static-consts\fR" 4 +.IP "\fB\-fkeep\-static\-consts\fR" 4 .IX Item "-fkeep-static-consts" Emit variables declared \f(CW\*(C`static const\*(C'\fR when optimization isn't turned on, even if the variables aren't referenced. .Sp \&\s-1GCC\s0 enables this option by default. If you want to force the compiler to check if the variable was referenced, regardless of whether or not -optimization is turned on, use the \fB\-fno-keep-static-consts\fR option. -.Ip "\fB\-fmerge-constants\fR" 4 +optimization is turned on, use the \fB\-fno\-keep\-static\-consts\fR option. +.IP "\fB\-fmerge\-constants\fR" 4 .IX Item "-fmerge-constants" Attempt to merge identical constants (string constants and floating point -constants) accross compilation units. +constants) across compilation units. .Sp -This option is default for optimized compilation if assembler and linker -support it. Use \fB\-fno-merge-constants\fR to inhibit this behavior. -.Ip "\fB\-fmerge-all-constants\fR" 4 +This option is the default for optimized compilation if the assembler and +linker support it. Use \fB\-fno\-merge\-constants\fR to inhibit this +behavior. +.Sp +Enabled at levels \fB\-O\fR, \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-fmerge\-all\-constants\fR" 4 .IX Item "-fmerge-all-constants" Attempt to merge identical constants and identical variables. .Sp -This option implies \fB\-fmerge-constants\fR. In addition to -\&\fB\-fmerge-constants\fR this considers e.g. even constant initialized +This option implies \fB\-fmerge\-constants\fR. In addition to +\&\fB\-fmerge\-constants\fR this considers e.g. even constant initialized arrays or initialized constant variables with integral or floating point types. Languages like C or \*(C+ require each non-automatic variable to have distinct location, so using this option will result in non-conforming behavior. -.Ip "\fB\-fno-branch-count-reg\fR" 4 +.IP "\fB\-fnew\-ra\fR" 4 +.IX Item "-fnew-ra" +Use a graph coloring register allocator. Currently this option is meant +only for testing. Users should not specify this option, since it is not +yet ready for production use. +.IP "\fB\-fno\-branch\-count\-reg\fR" 4 .IX Item "-fno-branch-count-reg" Do not use ``decrement and branch'' instructions on a count register, but instead generate a sequence of instructions that decrement a register, compare it against zero, then branch based upon the result. This option is only meaningful on architectures that support such -instructions, which include x86, PowerPC, \s-1IA-64\s0 and S/390. -.Ip "\fB\-fno-function-cse\fR" 4 +instructions, which include x86, PowerPC, \s-1IA\-64\s0 and S/390. +.Sp +The default is \fB\-fbranch\-count\-reg\fR, enabled when +\&\fB\-fstrength\-reduce\fR is enabled. +.IP "\fB\-fno\-function\-cse\fR" 4 .IX Item "-fno-function-cse" Do not put function addresses in registers; make each instruction that calls a constant function contain the function's address explicitly. @@ -3134,127 +3518,127 @@ calls a constant function contain the function's address explicitly. This option results in less efficient code, but some strange hacks that alter the assembler output may be confused by the optimizations performed when this option is not used. -.Ip "\fB\-ffast-math\fR" 4 -.IX Item "-ffast-math" -Sets \fB\-fno-math-errno\fR, \fB\-funsafe-math-optimizations\fR, and \fB\-fno-trapping-math\fR. -.Sp -This option causes the preprocessor macro \f(CW\*(C`_\|_FAST_MATH_\|_\*(C'\fR to be defined. -.Sp -This option should never be turned on by any \fB\-O\fR option since -it can result in incorrect output for programs which depend on -an exact implementation of \s-1IEEE\s0 or \s-1ISO\s0 rules/specifications for -math functions. -.Ip "\fB\-fno-math-errno\fR" 4 -.IX Item "-fno-math-errno" -Do not set \s-1ERRNO\s0 after calling math functions that are executed -with a single instruction, e.g., sqrt. A program that relies on -\&\s-1IEEE\s0 exceptions for math error handling may want to use this flag -for speed while maintaining \s-1IEEE\s0 arithmetic compatibility. -.Sp -This option should never be turned on by any \fB\-O\fR option since -it can result in incorrect output for programs which depend on -an exact implementation of \s-1IEEE\s0 or \s-1ISO\s0 rules/specifications for -math functions. .Sp -The default is \fB\-fmath-errno\fR. -.Ip "\fB\-funsafe-math-optimizations\fR" 4 -.IX Item "-funsafe-math-optimizations" -Allow optimizations for floating-point arithmetic that (a) assume -that arguments and results are valid and (b) may violate \s-1IEEE\s0 or -\&\s-1ANSI\s0 standards. When used at link-time, it may include libraries -or startup files that change the default \s-1FPU\s0 control word or other -similar optimizations. -.Sp -This option should never be turned on by any \fB\-O\fR option since -it can result in incorrect output for programs which depend on -an exact implementation of \s-1IEEE\s0 or \s-1ISO\s0 rules/specifications for -math functions. -.Sp -The default is \fB\-fno-unsafe-math-optimizations\fR. -.Ip "\fB\-fno-trapping-math\fR" 4 -.IX Item "-fno-trapping-math" -Compile code assuming that floating-point operations cannot generate -user-visible traps. Setting this option may allow faster code -if one relies on ``non-stop'' \s-1IEEE\s0 arithmetic, for example. +The default is \fB\-ffunction\-cse\fR +.IP "\fB\-fno\-zero\-initialized\-in\-bss\fR" 4 +.IX Item "-fno-zero-initialized-in-bss" +If the target supports a \s-1BSS\s0 section, \s-1GCC\s0 by default puts variables that +are initialized to zero into \s-1BSS\s0. This can save space in the resulting +code. .Sp -This option should never be turned on by any \fB\-O\fR option since -it can result in incorrect output for programs which depend on -an exact implementation of \s-1IEEE\s0 or \s-1ISO\s0 rules/specifications for -math functions. +This option turns off this behavior because some programs explicitly +rely on variables going to the data section. E.g., so that the +resulting executable can find the beginning of that section and/or make +assumptions based on that. .Sp -The default is \fB\-ftrapping-math\fR. -.Ip "\fB\-fbounds-check\fR" 4 -.IX Item "-fbounds-check" -For front-ends that support it, generate additional code to check that -indices used to access arrays are within the declared range. This is -currenly only supported by the Java and Fortran 77 front-ends, where -this option defaults to true and false respectively. -.PP -The following options control specific optimizations. The \fB\-O2\fR -option turns on all of these optimizations except \fB\-funroll-loops\fR -and \fB\-funroll-all-loops\fR. On most machines, the \fB\-O\fR option -turns on the \fB\-fthread-jumps\fR and \fB\-fdelayed-branch\fR options, -but specific machines may handle it differently. -.PP -You can use the following flags in the rare cases when ``fine-tuning'' -of optimizations to be performed is desired. -.PP -Not all of the optimizations performed by \s-1GCC\s0 have \fB\-f\fR options -to control them. -.Ip "\fB\-fstrength-reduce\fR" 4 +The default is \fB\-fzero\-initialized\-in\-bss\fR. +.IP "\fB\-fstrength\-reduce\fR" 4 .IX Item "-fstrength-reduce" Perform the optimizations of loop strength reduction and elimination of iteration variables. -.Ip "\fB\-fthread-jumps\fR" 4 +.Sp +Enabled at levels \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-fthread\-jumps\fR" 4 .IX Item "-fthread-jumps" Perform optimizations where we check to see if a jump branches to a location where another comparison subsumed by the first is found. If so, the first branch is redirected to either the destination of the second branch or a point immediately following it, depending on whether the condition is known to be true or false. -.Ip "\fB\-fcse-follow-jumps\fR" 4 +.Sp +Enabled at levels \fB\-O\fR, \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-fcse\-follow\-jumps\fR" 4 .IX Item "-fcse-follow-jumps" In common subexpression elimination, scan through jump instructions when the target of the jump is not reached by any other path. For example, when \s-1CSE\s0 encounters an \f(CW\*(C`if\*(C'\fR statement with an \&\f(CW\*(C`else\*(C'\fR clause, \s-1CSE\s0 will follow the jump when the condition tested is false. -.Ip "\fB\-fcse-skip-blocks\fR" 4 +.Sp +Enabled at levels \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-fcse\-skip\-blocks\fR" 4 .IX Item "-fcse-skip-blocks" -This is similar to \fB\-fcse-follow-jumps\fR, but causes \s-1CSE\s0 to +This is similar to \fB\-fcse\-follow\-jumps\fR, but causes \s-1CSE\s0 to follow jumps which conditionally skip over blocks. When \s-1CSE\s0 encounters a simple \f(CW\*(C`if\*(C'\fR statement with no else clause, -\&\fB\-fcse-skip-blocks\fR causes \s-1CSE\s0 to follow the jump around the +\&\fB\-fcse\-skip\-blocks\fR causes \s-1CSE\s0 to follow the jump around the body of the \f(CW\*(C`if\*(C'\fR. -.Ip "\fB\-frerun-cse-after-loop\fR" 4 +.Sp +Enabled at levels \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-frerun\-cse\-after\-loop\fR" 4 .IX Item "-frerun-cse-after-loop" Re-run common subexpression elimination after loop optimizations has been performed. -.Ip "\fB\-frerun-loop-opt\fR" 4 +.Sp +Enabled at levels \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-frerun\-loop\-opt\fR" 4 .IX Item "-frerun-loop-opt" Run the loop optimizer twice. -.Ip "\fB\-fgcse\fR" 4 +.Sp +Enabled at levels \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-fgcse\fR" 4 .IX Item "-fgcse" Perform a global common subexpression elimination pass. This pass also performs global constant and copy propagation. .Sp \&\fINote:\fR When compiling a program using computed gotos, a \s-1GCC\s0 extension, you may get better runtime performance if you disable -the global common subexpression elmination pass by adding -\&\fB\-fno-gcse\fR to the command line. -.Ip "\fB\-fgcse-lm\fR" 4 +the global common subexpression elimination pass by adding +\&\fB\-fno\-gcse\fR to the command line. +.Sp +Enabled at levels \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-fgcse\-lm\fR" 4 .IX Item "-fgcse-lm" -When \fB\-fgcse-lm\fR is enabled, global common subexpression elimination will +When \fB\-fgcse\-lm\fR is enabled, global common subexpression elimination will attempt to move loads which are only killed by stores into themselves. This allows a loop containing a load/store sequence to be changed to a load outside the loop, and a copy/store within the loop. -.Ip "\fB\-fgcse-sm\fR" 4 +.Sp +Enabled by default when gcse is enabled. +.IP "\fB\-fgcse\-sm\fR" 4 .IX Item "-fgcse-sm" -When \fB\-fgcse-sm\fR is enabled, A store motion pass is run after global common -subexpression elimination. This pass will attempt to move stores out of loops. -When used in conjunction with \fB\-fgcse-lm\fR, loops containing a load/store sequence -can be changed to a load before the loop and a store after the loop. -.Ip "\fB\-fdelete-null-pointer-checks\fR" 4 +When \fB\-fgcse\-sm\fR is enabled, a store motion pass is run after +global common subexpression elimination. This pass will attempt to move +stores out of loops. When used in conjunction with \fB\-fgcse\-lm\fR, +loops containing a load/store sequence can be changed to a load before +the loop and a store after the loop. +.Sp +Enabled by default when gcse is enabled. +.IP "\fB\-fgcse\-las\fR" 4 +.IX Item "-fgcse-las" +When \fB\-fgcse\-las\fR is enabled, the global common subexpression +elimination pass eliminates redundant loads that come after stores to the +same memory location (both partial and full redundancies). +.Sp +Enabled by default when gcse is enabled. +.IP "\fB\-floop\-optimize\fR" 4 +.IX Item "-floop-optimize" +Perform loop optimizations: move constant expressions out of loops, simplify +exit test conditions and optionally do strength-reduction and loop unrolling as +well. +.Sp +Enabled at levels \fB\-O\fR, \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-fcrossjumping\fR" 4 +.IX Item "-fcrossjumping" +Perform cross-jumping transformation. This transformation unifies equivalent code and save code size. The +resulting code may or may not perform better than without cross\-jumping. +.Sp +Enabled at levels \fB\-O\fR, \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-fif\-conversion\fR" 4 +.IX Item "-fif-conversion" +Attempt to transform conditional jumps into branch-less equivalents. This +include use of conditional moves, min, max, set flags and abs instructions, and +some tricks doable by standard arithmetics. The use of conditional execution +on chips where it is available is controlled by \f(CW\*(C`if\-conversion2\*(C'\fR. +.Sp +Enabled at levels \fB\-O\fR, \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-fif\-conversion2\fR" 4 +.IX Item "-fif-conversion2" +Use conditional execution (where available) to transform conditional jumps into +branch-less equivalents. +.Sp +Enabled at levels \fB\-O\fR, \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-fdelete\-null\-pointer\-checks\fR" 4 .IX Item "-fdelete-null-pointer-checks" Use global dataflow analysis to identify and eliminate useless checks for null pointers. The compiler assumes that dereferencing a null @@ -3263,87 +3647,107 @@ it has already been dereferenced, it cannot be null. .Sp In some environments, this assumption is not true, and programs can safely dereference null pointers. Use -\&\fB\-fno-delete-null-pointer-checks\fR to disable this optimization +\&\fB\-fno\-delete\-null\-pointer\-checks\fR to disable this optimization for programs which depend on that behavior. -.Ip "\fB\-fexpensive-optimizations\fR" 4 +.Sp +Enabled at levels \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-fexpensive\-optimizations\fR" 4 .IX Item "-fexpensive-optimizations" Perform a number of minor optimizations that are relatively expensive. -.Ip "\fB\-foptimize-register-move\fR" 4 +.Sp +Enabled at levels \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-foptimize\-register\-move\fR" 4 .IX Item "-foptimize-register-move" .PD 0 -.Ip "\fB\-fregmove\fR" 4 +.IP "\fB\-fregmove\fR" 4 .IX Item "-fregmove" .PD Attempt to reassign register numbers in move instructions and as operands of other simple instructions in order to maximize the amount of register tying. This is especially helpful on machines with two-operand -instructions. \s-1GCC\s0 enables this optimization by default with \fB\-O2\fR -or higher. +instructions. .Sp -Note \fB\-fregmove\fR and \fB\-foptimize-register-move\fR are the same +Note \fB\-fregmove\fR and \fB\-foptimize\-register\-move\fR are the same optimization. -.Ip "\fB\-fdelayed-branch\fR" 4 +.Sp +Enabled at levels \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-fdelayed\-branch\fR" 4 .IX Item "-fdelayed-branch" If supported for the target machine, attempt to reorder instructions to exploit instruction slots available after delayed branch instructions. -.Ip "\fB\-fschedule-insns\fR" 4 +.Sp +Enabled at levels \fB\-O\fR, \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-fschedule\-insns\fR" 4 .IX Item "-fschedule-insns" If supported for the target machine, attempt to reorder instructions to eliminate execution stalls due to required data being unavailable. This helps machines that have slow floating point or memory load instructions by allowing other instructions to be issued until the result of the load or floating point instruction is required. -.Ip "\fB\-fschedule-insns2\fR" 4 +.Sp +Enabled at levels \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-fschedule\-insns2\fR" 4 .IX Item "-fschedule-insns2" -Similar to \fB\-fschedule-insns\fR, but requests an additional pass of +Similar to \fB\-fschedule\-insns\fR, but requests an additional pass of instruction scheduling after register allocation has been done. This is especially useful on machines with a relatively small number of registers and where memory load instructions take more than one cycle. -.Ip "\fB\-fno-sched-interblock\fR" 4 +.Sp +Enabled at levels \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-fno\-sched\-interblock\fR" 4 .IX Item "-fno-sched-interblock" Don't schedule instructions across basic blocks. This is normally enabled by default when scheduling before register allocation, i.e. -with \fB\-fschedule-insns\fR or at \fB\-O2\fR or higher. -.Ip "\fB\-fno-sched-spec\fR" 4 +with \fB\-fschedule\-insns\fR or at \fB\-O2\fR or higher. +.IP "\fB\-fno\-sched\-spec\fR" 4 .IX Item "-fno-sched-spec" Don't allow speculative motion of non-load instructions. This is normally enabled by default when scheduling before register allocation, i.e. -with \fB\-fschedule-insns\fR or at \fB\-O2\fR or higher. -.Ip "\fB\-fsched-spec-load\fR" 4 +with \fB\-fschedule\-insns\fR or at \fB\-O2\fR or higher. +.IP "\fB\-fsched\-spec\-load\fR" 4 .IX Item "-fsched-spec-load" Allow speculative motion of some load instructions. This only makes sense when scheduling before register allocation, i.e. with -\&\fB\-fschedule-insns\fR or at \fB\-O2\fR or higher. -.Ip "\fB\-fsched-spec-load-dangerous\fR" 4 +\&\fB\-fschedule\-insns\fR or at \fB\-O2\fR or higher. +.IP "\fB\-fsched\-spec\-load\-dangerous\fR" 4 .IX Item "-fsched-spec-load-dangerous" Allow speculative motion of more load instructions. This only makes sense when scheduling before register allocation, i.e. with -\&\fB\-fschedule-insns\fR or at \fB\-O2\fR or higher. -.Ip "\fB\-ffunction-sections\fR" 4 -.IX Item "-ffunction-sections" -.PD 0 -.Ip "\fB\-fdata-sections\fR" 4 -.IX Item "-fdata-sections" -.PD -Place each function or data item into its own section in the output -file if the target supports arbitrary sections. The name of the -function or the name of the data item determines the section's name -in the output file. -.Sp -Use these options on systems where the linker can perform optimizations -to improve locality of reference in the instruction space. \s-1HPPA\s0 -processors running \s-1HP-UX\s0 and Sparc processors running Solaris 2 have -linkers with such optimizations. Other systems using the \s-1ELF\s0 object format -as well as \s-1AIX\s0 may have these optimizations in the future. -.Sp -Only use these options when there are significant benefits from doing -so. When you specify these options, the assembler and linker will -create larger object and executable files and will also be slower. -You will not be able to use \f(CW\*(C`gprof\*(C'\fR on all systems if you -specify this option and you may have problems with debugging if -you specify both this option and \fB\-g\fR. -.Ip "\fB\-fcaller-saves\fR" 4 +\&\fB\-fschedule\-insns\fR or at \fB\-O2\fR or higher. +.IP "\fB\-fsched\-stalled\-insns=\fR\fIn\fR" 4 +.IX Item "-fsched-stalled-insns=n" +Define how many insns (if any) can be moved prematurely from the queue +of stalled insns into the ready list, during the second scheduling pass. +.IP "\fB\-fsched\-stalled\-insns\-dep=\fR\fIn\fR" 4 +.IX Item "-fsched-stalled-insns-dep=n" +Define how many insn groups (cycles) will be examined for a dependency +on a stalled insn that is candidate for premature removal from the queue +of stalled insns. Has an effect only during the second scheduling pass, +and only if \fB\-fsched\-stalled\-insns\fR is used and its value is not zero. +.IP "\fB\-fsched2\-use\-superblocks\fR" 4 +.IX Item "-fsched2-use-superblocks" +When scheduling after register allocation, do use superblock scheduling +algorithm. Superblock scheduling allows motion across basic block boundaries +resulting on faster schedules. This option is experimental, as not all machine +descriptions used by \s-1GCC\s0 model the \s-1CPU\s0 closely enough to avoid unreliable +results from the algorithm. +.Sp +This only makes sense when scheduling after register allocation, i.e. with +\&\fB\-fschedule\-insns2\fR or at \fB\-O2\fR or higher. +.IP "\fB\-fsched2\-use\-traces\fR" 4 +.IX Item "-fsched2-use-traces" +Use \fB\-fsched2\-use\-superblocks\fR algorithm when scheduling after register +allocation and additionally perform code duplication in order to increase the +size of superblocks using tracer pass. See \fB\-ftracer\fR for details on +trace formation. +.Sp +This mode should produce faster but significantly longer programs. Also +without \f(CW\*(C`\-fbranch\-probabilities\*(C'\fR the traces constructed may not match the +reality and hurt the performance. This only makes +sense when scheduling after register allocation, i.e. with +\&\fB\-fschedule\-insns2\fR or at \fB\-O2\fR or higher. +.IP "\fB\-fcaller\-saves\fR" 4 .IX Item "-fcaller-saves" Enable values to be allocated in registers that will be clobbered by function calls, by emitting extra instructions to save and restore the @@ -3353,35 +3757,18 @@ seems to result in better code than would otherwise be produced. This option is always enabled by default on certain machines, usually those which have no call-preserved registers to use instead. .Sp -For all machines, optimization level 2 and higher enables this flag by -default. -.Ip "\fB\-funroll-loops\fR" 4 -.IX Item "-funroll-loops" -Unroll loops whose number of iterations can be determined at compile -time or upon entry to the loop. \fB\-funroll-loops\fR implies both -\&\fB\-fstrength-reduce\fR and \fB\-frerun-cse-after-loop\fR. This -option makes code larger, and may or may not make it run faster. -.Ip "\fB\-funroll-all-loops\fR" 4 -.IX Item "-funroll-all-loops" -Unroll all loops, even if their number of iterations is uncertain when -the loop is entered. This usually makes programs run more slowly. -\&\fB\-funroll-all-loops\fR implies the same options as -\&\fB\-funroll-loops\fR, -.Ip "\fB\-fprefetch-loop-arrays\fR" 4 -.IX Item "-fprefetch-loop-arrays" -If supported by the target machine, generate instructions to prefetch -memory to improve the performance of loops that access large arrays. -.Ip "\fB\-fmove-all-movables\fR" 4 +Enabled at levels \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-fmove\-all\-movables\fR" 4 .IX Item "-fmove-all-movables" Forces all invariant computations in loops to be moved outside the loop. -.Ip "\fB\-freduce-all-givs\fR" 4 +.IP "\fB\-freduce\-all\-givs\fR" 4 .IX Item "-freduce-all-givs" Forces all general-induction variables in loops to be -strength-reduced. +strength\-reduced. .Sp \&\fINote:\fR When compiling programs written in Fortran, -\&\fB\-fmove-all-movables\fR and \fB\-freduce-all-givs\fR are enabled +\&\fB\-fmove\-all\-movables\fR and \fB\-freduce\-all\-givs\fR are enabled by default when you use the optimizer. .Sp These options may generate better or worse code; results are highly @@ -3391,55 +3778,61 @@ These two options are intended to be removed someday, once they have helped determine the efficacy of various approaches to improving loop optimizations. .Sp -Please let us (<\fBgcc@gcc.gnu.org\fR> and <\fBfortran@gnu.org\fR>) -know how use of these options affects -the performance of your production code. -We're very interested in code that runs \fIslower\fR -when these options are \fIenabled\fR. -.Ip "\fB\-fno-peephole\fR" 4 +Please contact <\fBgcc@gcc.gnu.org\fR>, and describe how use of +these options affects the performance of your production code. +Examples of code that runs \fIslower\fR when these options are +\&\fIenabled\fR are very valuable. +.IP "\fB\-fno\-peephole\fR" 4 .IX Item "-fno-peephole" .PD 0 -.Ip "\fB\-fno-peephole2\fR" 4 +.IP "\fB\-fno\-peephole2\fR" 4 .IX Item "-fno-peephole2" .PD Disable any machine-specific peephole optimizations. The difference -between \fB\-fno-peephole\fR and \fB\-fno-peephole2\fR is in how they +between \fB\-fno\-peephole\fR and \fB\-fno\-peephole2\fR is in how they are implemented in the compiler; some targets use one, some use the other, a few use both. -.Ip "\fB\-fbranch-probabilities\fR" 4 -.IX Item "-fbranch-probabilities" -After running a program compiled with \fB\-fprofile-arcs\fR, you can compile it a second time using -\&\fB\-fbranch-probabilities\fR, to improve optimizations based on -the number of times each branch was taken. When the program -compiled with \fB\-fprofile-arcs\fR exits it saves arc execution -counts to a file called \fI\fIsourcename\fI.da\fR for each source -file The information in this data file is very dependent on the -structure of the generated code, so you must use the same source code -and the same optimization options for both compilations. .Sp -With \fB\-fbranch-probabilities\fR, \s-1GCC\s0 puts a \fB\s-1REG_EXEC_COUNT\s0\fR -note on the first instruction of each basic block, and a -\&\fB\s-1REG_BR_PROB\s0\fR note on each \fB\s-1JUMP_INSN\s0\fR and \fB\s-1CALL_INSN\s0\fR. -These can be used to improve optimization. Currently, they are only -used in one place: in \fIreorg.c\fR, instead of guessing which path a -branch is mostly to take, the \fB\s-1REG_BR_PROB\s0\fR values are used to -exactly determine which path is taken more often. -.Ip "\fB\-fno-guess-branch-probability\fR" 4 +\&\fB\-fpeephole\fR is enabled by default. +\&\fB\-fpeephole2\fR enabled at levels \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-fno\-guess\-branch\-probability\fR" 4 .IX Item "-fno-guess-branch-probability" Do not guess branch probabilities using a randomized model. .Sp -Sometimes gcc will opt to use a randomized model to guess branch +Sometimes \s-1GCC\s0 will opt to use a randomized model to guess branch probabilities, when none are available from either profiling feedback -(\fB\-fprofile-arcs\fR) or \fB_\|_builtin_expect\fR. This means that +(\fB\-fprofile\-arcs\fR) or \fB_\|_builtin_expect\fR. This means that different runs of the compiler on the same program may produce different object code. .Sp In a hard real-time system, people don't want different runs of the compiler to produce code that has different behavior; minimizing non-determinism is of paramount import. This switch allows users to -reduce non-determinism, possibly at the expense of inferior +reduce non\-determinism, possibly at the expense of inferior optimization. -.Ip "\fB\-fstrict-aliasing\fR" 4 +.Sp +The default is \fB\-fguess\-branch\-probability\fR at levels +\&\fB\-O\fR, \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-freorder\-blocks\fR" 4 +.IX Item "-freorder-blocks" +Reorder basic blocks in the compiled function in order to reduce number of +taken branches and improve code locality. +.Sp +Enabled at levels \fB\-O2\fR, \fB\-O3\fR. +.IP "\fB\-freorder\-functions\fR" 4 +.IX Item "-freorder-functions" +Reorder basic blocks in the compiled function in order to reduce number of +taken branches and improve code locality. This is implemented by using special +subsections \f(CW\*(C`.text.hot\*(C'\fR for most frequently executed functions and +\&\f(CW\*(C`.text.unlikely\*(C'\fR for unlikely executed functions. Reordering is done by +the linker so object file format must support named sections and linker must +place them in a reasonable way. +.Sp +Also profile feedback must be available in to make this option effective. See +\&\fB\-fprofile\-arcs\fR for details. +.Sp +Enabled at levels \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-fstrict\-aliasing\fR" 4 .IX Item "-fstrict-aliasing" Allows the compiler to assume the strictest aliasing rules applicable to the language being compiled. For C (and \*(C+), this activates @@ -3458,6 +3851,7 @@ Pay special attention to code like this: \& double d; \& }; .Ve +.Sp .Vb 5 \& int f() { \& a_union t; @@ -3465,9 +3859,10 @@ Pay special attention to code like this: \& return t.i; \& } .Ve +.Sp The practice of reading from a different union member than the one most -recently written to (called ``type-punning'') is common. Even with -\&\fB\-fstrict-aliasing\fR, type-punning is allowed, provided the memory +recently written to (called ``type\-punning'') is common. Even with +\&\fB\-fstrict\-aliasing\fR, type-punning is allowed, provided the memory is accessed through the union type. So, the code above will work as expected. However, this code might not: .Sp @@ -3480,112 +3875,405 @@ expected. However, this code might not: \& return *ip; \& } .Ve +.Sp Every language that wishes to perform language-specific alias analysis should define a function that computes, given an \f(CW\*(C`tree\*(C'\fR node, an alias set for the node. Nodes in different alias sets are not allowed to alias. For an example, see the C front-end function \&\f(CW\*(C`c_get_alias_set\*(C'\fR. -.Ip "\fB\-falign-functions\fR" 4 +.Sp +Enabled at levels \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-falign\-functions\fR" 4 .IX Item "-falign-functions" .PD 0 -.Ip "\fB\-falign-functions=\fR\fIn\fR" 4 +.IP "\fB\-falign\-functions=\fR\fIn\fR" 4 .IX Item "-falign-functions=n" .PD Align the start of functions to the next power-of-two greater than \&\fIn\fR, skipping up to \fIn\fR bytes. For instance, -\&\fB\-falign-functions=32\fR aligns functions to the next 32\-byte -boundary, but \fB\-falign-functions=24\fR would align to the next +\&\fB\-falign\-functions=32\fR aligns functions to the next 32\-byte +boundary, but \fB\-falign\-functions=24\fR would align to the next 32\-byte boundary only if this can be done by skipping 23 bytes or less. .Sp -\&\fB\-fno-align-functions\fR and \fB\-falign-functions=1\fR are +\&\fB\-fno\-align\-functions\fR and \fB\-falign\-functions=1\fR are equivalent and mean that functions will not be aligned. .Sp Some assemblers only support this flag when \fIn\fR is a power of two; in that case, it is rounded up. .Sp -If \fIn\fR is not specified, use a machine-dependent default. -.Ip "\fB\-falign-labels\fR" 4 +If \fIn\fR is not specified or is zero, use a machine-dependent default. +.Sp +Enabled at levels \fB\-O2\fR, \fB\-O3\fR. +.IP "\fB\-falign\-labels\fR" 4 .IX Item "-falign-labels" .PD 0 -.Ip "\fB\-falign-labels=\fR\fIn\fR" 4 +.IP "\fB\-falign\-labels=\fR\fIn\fR" 4 .IX Item "-falign-labels=n" .PD Align all branch targets to a power-of-two boundary, skipping up to -\&\fIn\fR bytes like \fB\-falign-functions\fR. This option can easily +\&\fIn\fR bytes like \fB\-falign\-functions\fR. This option can easily make code slower, because it must insert dummy operations for when the branch target is reached in the usual flow of the code. .Sp -If \fB\-falign-loops\fR or \fB\-falign-jumps\fR are applicable and +\&\fB\-fno\-align\-labels\fR and \fB\-falign\-labels=1\fR are +equivalent and mean that labels will not be aligned. +.Sp +If \fB\-falign\-loops\fR or \fB\-falign\-jumps\fR are applicable and are greater than this value, then their values are used instead. .Sp -If \fIn\fR is not specified, use a machine-dependent default which is -very likely to be \fB1\fR, meaning no alignment. -.Ip "\fB\-falign-loops\fR" 4 +If \fIn\fR is not specified or is zero, use a machine-dependent default +which is very likely to be \fB1\fR, meaning no alignment. +.Sp +Enabled at levels \fB\-O2\fR, \fB\-O3\fR. +.IP "\fB\-falign\-loops\fR" 4 .IX Item "-falign-loops" .PD 0 -.Ip "\fB\-falign-loops=\fR\fIn\fR" 4 +.IP "\fB\-falign\-loops=\fR\fIn\fR" 4 .IX Item "-falign-loops=n" .PD Align loops to a power-of-two boundary, skipping up to \fIn\fR bytes -like \fB\-falign-functions\fR. The hope is that the loop will be +like \fB\-falign\-functions\fR. The hope is that the loop will be executed many times, which will make up for any execution of the dummy operations. .Sp -If \fIn\fR is not specified, use a machine-dependent default. -.Ip "\fB\-falign-jumps\fR" 4 +\&\fB\-fno\-align\-loops\fR and \fB\-falign\-loops=1\fR are +equivalent and mean that loops will not be aligned. +.Sp +If \fIn\fR is not specified or is zero, use a machine-dependent default. +.Sp +Enabled at levels \fB\-O2\fR, \fB\-O3\fR. +.IP "\fB\-falign\-jumps\fR" 4 .IX Item "-falign-jumps" .PD 0 -.Ip "\fB\-falign-jumps=\fR\fIn\fR" 4 +.IP "\fB\-falign\-jumps=\fR\fIn\fR" 4 .IX Item "-falign-jumps=n" .PD Align branch targets to a power-of-two boundary, for branch targets where the targets can only be reached by jumping, skipping up to \fIn\fR -bytes like \fB\-falign-functions\fR. In this case, no dummy operations +bytes like \fB\-falign\-functions\fR. In this case, no dummy operations need be executed. .Sp -If \fIn\fR is not specified, use a machine-dependent default. -.Ip "\fB\-fssa\fR" 4 -.IX Item "-fssa" -Perform optimizations in static single assignment form. Each function's -flow graph is translated into \s-1SSA\s0 form, optimizations are performed, and -the flow graph is translated back from \s-1SSA\s0 form. Users should not -specify this option, since it is not yet ready for production use. -.Ip "\fB\-fssa-ccp\fR" 4 -.IX Item "-fssa-ccp" -Perform Sparse Conditional Constant Propagation in \s-1SSA\s0 form. Requires -\&\fB\-fssa\fR. Like \fB\-fssa\fR, this is an experimental feature. -.Ip "\fB\-fssa-dce\fR" 4 -.IX Item "-fssa-dce" -Perform aggressive dead-code elimination in \s-1SSA\s0 form. Requires \fB\-fssa\fR. -Like \fB\-fssa\fR, this is an experimental feature. -.Ip "\fB\-fsingle-precision-constant\fR" 4 -.IX Item "-fsingle-precision-constant" -Treat floating point constant as single precision constant instead of -implicitly converting it to double precision constant. -.Ip "\fB\-frename-registers\fR" 4 +\&\fB\-fno\-align\-jumps\fR and \fB\-falign\-jumps=1\fR are +equivalent and mean that loops will not be aligned. +.Sp +If \fIn\fR is not specified or is zero, use a machine-dependent default. +.Sp +Enabled at levels \fB\-O2\fR, \fB\-O3\fR. +.IP "\fB\-frename\-registers\fR" 4 .IX Item "-frename-registers" Attempt to avoid false dependencies in scheduled code by making use of registers left over after register allocation. This optimization will most benefit processors with lots of registers. It can, however, make debugging impossible, since variables will no longer stay in a ``home register''. -.Ip "\fB\-fno-cprop-registers\fR" 4 +.IP "\fB\-fweb\fR" 4 +.IX Item "-fweb" +Constructs webs as commonly used for register allocation purposes and assign +each web individual pseudo register. This allows the register allocation pass +to operate on pseudos directly, but also strengthens several other optimization +passes, such as \s-1CSE\s0, loop optimizer and trivial dead code remover. It can, +however, make debugging impossible, since variables will no longer stay in a +``home register''. +.Sp +Enabled at levels \fB\-O3\fR. +.IP "\fB\-fno\-cprop\-registers\fR" 4 .IX Item "-fno-cprop-registers" After register allocation and post-register allocation instruction splitting, we perform a copy-propagation pass to try to reduce scheduling dependencies and occasionally eliminate the copy. -.Ip "\fB\*(--param\fR \fIname\fR\fB=\fR\fIvalue\fR" 4 -.IX Item "param name=value" +.Sp +Disabled at levels \fB\-O\fR, \fB\-O2\fR, \fB\-O3\fR, \fB\-Os\fR. +.IP "\fB\-fprofile\-generate\fR" 4 +.IX Item "-fprofile-generate" +Enable options usually used for instrumenting application to produce +profile useful for later recompilation with profile feedback based +optimization. You must use \f(CW\*(C`\-fprofile\-generate\*(C'\fR both when +compiling and when linking your program. +.Sp +The following options are enabled: \f(CW\*(C`\-fprofile\-arcs\*(C'\fR, \f(CW\*(C`\-fprofile\-values\*(C'\fR, \f(CW\*(C`\-fvpt\*(C'\fR. +.IP "\fB\-fprofile\-use\fR" 4 +.IX Item "-fprofile-use" +Enable profile feedback directed optimizations, and optimizations +generally profitable only with profile feedback available. +.Sp +The following options are enabled: \f(CW\*(C`\-fbranch\-probabilities\*(C'\fR, +\&\f(CW\*(C`\-fvpt\*(C'\fR, \f(CW\*(C`\-funroll\-loops\*(C'\fR, \f(CW\*(C`\-fpeel\-loops\*(C'\fR, \f(CW\*(C`\-ftracer\*(C'\fR. +.PP +The following options control compiler behavior regarding floating +point arithmetic. These options trade off between speed and +correctness. All must be specifically enabled. +.IP "\fB\-ffloat\-store\fR" 4 +.IX Item "-ffloat-store" +Do not store floating point variables in registers, and inhibit other +options that might change whether a floating point value is taken from a +register or memory. +.Sp +This option prevents undesirable excess precision on machines such as +the 68000 where the floating registers (of the 68881) keep more +precision than a \f(CW\*(C`double\*(C'\fR is supposed to have. Similarly for the +x86 architecture. For most programs, the excess precision does only +good, but a few programs rely on the precise definition of \s-1IEEE\s0 floating +point. Use \fB\-ffloat\-store\fR for such programs, after modifying +them to store all pertinent intermediate computations into variables. +.IP "\fB\-ffast\-math\fR" 4 +.IX Item "-ffast-math" +Sets \fB\-fno\-math\-errno\fR, \fB\-funsafe\-math\-optimizations\fR, \fB\-fno\-trapping\-math\fR, \fB\-ffinite\-math\-only\fR, +\&\fB\-fno\-rounding\-math\fR and \fB\-fno\-signaling\-nans\fR. +.Sp +This option causes the preprocessor macro \f(CW\*(C`_\|_FAST_MATH_\|_\*(C'\fR to be defined. +.Sp +This option should never be turned on by any \fB\-O\fR option since +it can result in incorrect output for programs which depend on +an exact implementation of \s-1IEEE\s0 or \s-1ISO\s0 rules/specifications for +math functions. +.IP "\fB\-fno\-math\-errno\fR" 4 +.IX Item "-fno-math-errno" +Do not set \s-1ERRNO\s0 after calling math functions that are executed +with a single instruction, e.g., sqrt. A program that relies on +\&\s-1IEEE\s0 exceptions for math error handling may want to use this flag +for speed while maintaining \s-1IEEE\s0 arithmetic compatibility. +.Sp +This option should never be turned on by any \fB\-O\fR option since +it can result in incorrect output for programs which depend on +an exact implementation of \s-1IEEE\s0 or \s-1ISO\s0 rules/specifications for +math functions. +.Sp +The default is \fB\-fmath\-errno\fR. +.IP "\fB\-funsafe\-math\-optimizations\fR" 4 +.IX Item "-funsafe-math-optimizations" +Allow optimizations for floating-point arithmetic that (a) assume +that arguments and results are valid and (b) may violate \s-1IEEE\s0 or +\&\s-1ANSI\s0 standards. When used at link\-time, it may include libraries +or startup files that change the default \s-1FPU\s0 control word or other +similar optimizations. +.Sp +This option should never be turned on by any \fB\-O\fR option since +it can result in incorrect output for programs which depend on +an exact implementation of \s-1IEEE\s0 or \s-1ISO\s0 rules/specifications for +math functions. +.Sp +The default is \fB\-fno\-unsafe\-math\-optimizations\fR. +.IP "\fB\-ffinite\-math\-only\fR" 4 +.IX Item "-ffinite-math-only" +Allow optimizations for floating-point arithmetic that assume +that arguments and results are not NaNs or +\-Infs. +.Sp +This option should never be turned on by any \fB\-O\fR option since +it can result in incorrect output for programs which depend on +an exact implementation of \s-1IEEE\s0 or \s-1ISO\s0 rules/specifications. +.Sp +The default is \fB\-fno\-finite\-math\-only\fR. +.IP "\fB\-fno\-trapping\-math\fR" 4 +.IX Item "-fno-trapping-math" +Compile code assuming that floating-point operations cannot generate +user-visible traps. These traps include division by zero, overflow, +underflow, inexact result and invalid operation. This option implies +\&\fB\-fno\-signaling\-nans\fR. Setting this option may allow faster +code if one relies on ``non\-stop'' \s-1IEEE\s0 arithmetic, for example. +.Sp +This option should never be turned on by any \fB\-O\fR option since +it can result in incorrect output for programs which depend on +an exact implementation of \s-1IEEE\s0 or \s-1ISO\s0 rules/specifications for +math functions. +.Sp +The default is \fB\-ftrapping\-math\fR. +.IP "\fB\-frounding\-math\fR" 4 +.IX Item "-frounding-math" +Disable transformations and optimizations that assume default floating +point rounding behavior. This is round-to-zero for all floating point +to integer conversions, and round-to-nearest for all other arithmetic +truncations. This option should be specified for programs that change +the \s-1FP\s0 rounding mode dynamically, or that may be executed with a +non-default rounding mode. This option disables constant folding of +floating point expressions at compile-time (which may be affected by +rounding mode) and arithmetic transformations that are unsafe in the +presence of sign-dependent rounding modes. +.Sp +The default is \fB\-fno\-rounding\-math\fR. +.Sp +This option is experimental and does not currently guarantee to +disable all \s-1GCC\s0 optimizations that are affected by rounding mode. +Future versions of \s-1GCC\s0 may provide finer control of this setting +using C99's \f(CW\*(C`FENV_ACCESS\*(C'\fR pragma. This command line option +will be used to specify the default state for \f(CW\*(C`FENV_ACCESS\*(C'\fR. +.IP "\fB\-fsignaling\-nans\fR" 4 +.IX Item "-fsignaling-nans" +Compile code assuming that \s-1IEEE\s0 signaling NaNs may generate user-visible +traps during floating-point operations. Setting this option disables +optimizations that may change the number of exceptions visible with +signaling NaNs. This option implies \fB\-ftrapping\-math\fR. +.Sp +This option causes the preprocessor macro \f(CW\*(C`_\|_SUPPORT_SNAN_\|_\*(C'\fR to +be defined. +.Sp +The default is \fB\-fno\-signaling\-nans\fR. +.Sp +This option is experimental and does not currently guarantee to +disable all \s-1GCC\s0 optimizations that affect signaling NaN behavior. +.IP "\fB\-fsingle\-precision\-constant\fR" 4 +.IX Item "-fsingle-precision-constant" +Treat floating point constant as single precision constant instead of +implicitly converting it to double precision constant. +.PP +The following options control optimizations that may improve +performance, but are not enabled by any \fB\-O\fR options. This +section includes experimental options that may produce broken code. +.IP "\fB\-fbranch\-probabilities\fR" 4 +.IX Item "-fbranch-probabilities" +After running a program compiled with \fB\-fprofile\-arcs\fR, you can compile it a second time using +\&\fB\-fbranch\-probabilities\fR, to improve optimizations based on +the number of times each branch was taken. When the program +compiled with \fB\-fprofile\-arcs\fR exits it saves arc execution +counts to a file called \fI\fIsourcename\fI.gcda\fR for each source +file The information in this data file is very dependent on the +structure of the generated code, so you must use the same source code +and the same optimization options for both compilations. +.Sp +With \fB\-fbranch\-probabilities\fR, \s-1GCC\s0 puts a +\&\fB\s-1REG_BR_PROB\s0\fR note on each \fB\s-1JUMP_INSN\s0\fR and \fB\s-1CALL_INSN\s0\fR. +These can be used to improve optimization. Currently, they are only +used in one place: in \fIreorg.c\fR, instead of guessing which path a +branch is mostly to take, the \fB\s-1REG_BR_PROB\s0\fR values are used to +exactly determine which path is taken more often. +.IP "\fB\-fprofile\-values\fR" 4 +.IX Item "-fprofile-values" +If combined with \fB\-fprofile\-arcs\fR, it adds code so that some +data about values of expressions in the program is gathered. +.Sp +With \fB\-fbranch\-probabilities\fR, it reads back the data gathered +from profiling values of expressions and adds \fB\s-1REG_VALUE_PROFILE\s0\fR +notes to instructions for their later usage in optimizations. +.IP "\fB\-fvpt\fR" 4 +.IX Item "-fvpt" +If combined with \fB\-fprofile\-arcs\fR, it instructs the compiler to add +a code to gather information about values of expressions. +.Sp +With \fB\-fbranch\-probabilities\fR, it reads back the data gathered +and actually performs the optimizations based on them. +Currently the optimizations include specialization of division operation +using the knowledge about the value of the denominator. +.IP "\fB\-fnew\-ra\fR" 4 +.IX Item "-fnew-ra" +Use a graph coloring register allocator. Currently this option is meant +for testing, so we are interested to hear about miscompilations with +\&\fB\-fnew\-ra\fR. +.IP "\fB\-ftracer\fR" 4 +.IX Item "-ftracer" +Perform tail duplication to enlarge superblock size. This transformation +simplifies the control flow of the function allowing other optimizations to do +better job. +.IP "\fB\-funit\-at\-a\-time\fR" 4 +.IX Item "-funit-at-a-time" +Parse the whole compilation unit before starting to produce code. +This allows some extra optimizations to take place but consumes more +memory. +.IP "\fB\-funroll\-loops\fR" 4 +.IX Item "-funroll-loops" +Unroll loops whose number of iterations can be determined at compile time or +upon entry to the loop. \fB\-funroll\-loops\fR implies +\&\fB\-frerun\-cse\-after\-loop\fR. It also turns on complete loop peeling +(i.e. complete removal of loops with small constant number of iterations). +This option makes code larger, and may or may not make it run faster. +.IP "\fB\-funroll\-all\-loops\fR" 4 +.IX Item "-funroll-all-loops" +Unroll all loops, even if their number of iterations is uncertain when +the loop is entered. This usually makes programs run more slowly. +\&\fB\-funroll\-all\-loops\fR implies the same options as +\&\fB\-funroll\-loops\fR. +.IP "\fB\-fpeel\-loops\fR" 4 +.IX Item "-fpeel-loops" +Peels the loops for that there is enough information that they do not +roll much (from profile feedback). It also turns on complete loop peeling +(i.e. complete removal of loops with small constant number of iterations). +.IP "\fB\-funswitch\-loops\fR" 4 +.IX Item "-funswitch-loops" +Move branches with loop invariant conditions out of the loop, with duplicates +of the loop on both branches (modified according to result of the condition). +.IP "\fB\-fold\-unroll\-loops\fR" 4 +.IX Item "-fold-unroll-loops" +Unroll loops whose number of iterations can be determined at compile +time or upon entry to the loop, using the old loop unroller whose loop +recognition is based on notes from frontend. \fB\-fold\-unroll\-loops\fR implies +both \fB\-fstrength\-reduce\fR and \fB\-frerun\-cse\-after\-loop\fR. This +option makes code larger, and may or may not make it run faster. +.IP "\fB\-fold\-unroll\-all\-loops\fR" 4 +.IX Item "-fold-unroll-all-loops" +Unroll all loops, even if their number of iterations is uncertain when +the loop is entered. This is done using the old loop unroller whose loop +recognition is based on notes from frontend. This usually makes programs run more slowly. +\&\fB\-fold\-unroll\-all\-loops\fR implies the same options as +\&\fB\-fold\-unroll\-loops\fR. +.IP "\fB\-funswitch\-loops\fR" 4 +.IX Item "-funswitch-loops" +Move branches with loop invariant conditions out of the loop, with duplicates +of the loop on both branches (modified according to result of the condition). +.IP "\fB\-funswitch\-loops\fR" 4 +.IX Item "-funswitch-loops" +Move branches with loop invariant conditions out of the loop, with duplicates +of the loop on both branches (modified according to result of the condition). +.IP "\fB\-fprefetch\-loop\-arrays\fR" 4 +.IX Item "-fprefetch-loop-arrays" +If supported by the target machine, generate instructions to prefetch +memory to improve the performance of loops that access large arrays. +.Sp +Disabled at level \fB\-Os\fR. +.IP "\fB\-ffunction\-sections\fR" 4 +.IX Item "-ffunction-sections" +.PD 0 +.IP "\fB\-fdata\-sections\fR" 4 +.IX Item "-fdata-sections" +.PD +Place each function or data item into its own section in the output +file if the target supports arbitrary sections. The name of the +function or the name of the data item determines the section's name +in the output file. +.Sp +Use these options on systems where the linker can perform optimizations +to improve locality of reference in the instruction space. Most systems +using the \s-1ELF\s0 object format and \s-1SPARC\s0 processors running Solaris 2 have +linkers with such optimizations. \s-1AIX\s0 may have these optimizations in +the future. +.Sp +Only use these options when there are significant benefits from doing +so. When you specify these options, the assembler and linker will +create larger object and executable files and will also be slower. +You will not be able to use \f(CW\*(C`gprof\*(C'\fR on all systems if you +specify this option and you may have problems with debugging if +you specify both this option and \fB\-g\fR. +.IP "\fB\-fbranch\-target\-load\-optimize\fR" 4 +.IX Item "-fbranch-target-load-optimize" +Perform branch target register load optimization before prologue / epilogue +threading. +The use of target registers can typically be exposed only during reload, +thus hoisting loads out of loops and doing inter-block scheduling needs +a separate optimization pass. +.IP "\fB\-fbranch\-target\-load\-optimize2\fR" 4 +.IX Item "-fbranch-target-load-optimize2" +Perform branch target register load optimization after prologue / epilogue +threading. +.IP "\fB\-\-param\fR \fIname\fR\fB=\fR\fIvalue\fR" 4 +.IX Item "--param name=value" In some places, \s-1GCC\s0 uses various constants to control the amount of optimization that is done. For example, \s-1GCC\s0 will not inline functions that contain more that a certain number of instructions. You can control some of these constants on the command-line using the -\&\fB\*(--param\fR option. +\&\fB\-\-param\fR option. +.Sp +The names of specific parameters, and the meaning of the values, are +tied to the internals of the compiler, and are subject to change +without notice in future releases. .Sp In each case, the \fIvalue\fR is an integer. The allowable choices for \&\fIname\fR are given in the following table: .RS 4 -.Ip "\fBmax-delay-slot-insn-search\fR" 4 +.IP "\fBmax-crossjump-edges\fR" 4 +.IX Item "max-crossjump-edges" +The maximum number of incoming edges to consider for crossjumping. +The algorithm used by \fB\-fcrossjumping\fR is O(N^2) in +the number of edges incoming to each block. Increasing values mean +more aggressive optimization, making the compile time increase with +probably small improvement in executable size. +.IP "\fBmax-delay-slot-insn-search\fR" 4 .IX Item "max-delay-slot-insn-search" The maximum number of instructions to consider when looking for an instruction to fill a delay slot. If more than this arbitrary number of @@ -3593,7 +4281,7 @@ instructions is searched, the time savings from filling the delay slot will be minimal so stop searching. Increasing values mean more aggressive optimization, making the compile time increase with probably small improvement in executable run time. -.Ip "\fBmax-delay-slot-live-search\fR" 4 +.IP "\fBmax-delay-slot-live-search\fR" 4 .IX Item "max-delay-slot-live-search" When trying to fill delay slots, the maximum number of instructions to consider when searching for a block with valid live register @@ -3601,26 +4289,204 @@ information. Increasing this arbitrarily chosen value means more aggressive optimization, increasing the compile time. This parameter should be removed when the delay slot code is rewritten to maintain the control-flow graph. -.Ip "\fBmax-gcse-memory\fR" 4 +.IP "\fBmax-gcse-memory\fR" 4 .IX Item "max-gcse-memory" The approximate maximum amount of memory that will be allocated in order to perform the global common subexpression elimination optimization. If more memory than specified is required, the optimization will not be done. -.Ip "\fBmax-gcse-passes\fR" 4 +.IP "\fBmax-gcse-passes\fR" 4 .IX Item "max-gcse-passes" The maximum number of passes of \s-1GCSE\s0 to run. -.Ip "\fBmax-pending-list-length\fR" 4 +.IP "\fBmax-pending-list-length\fR" 4 .IX Item "max-pending-list-length" The maximum number of pending dependencies scheduling will allow before flushing the current state and starting over. Large functions with few branches or calls can create excessively large lists which needlessly consume memory and resources. -.Ip "\fBmax-inline-insns\fR" 4 -.IX Item "max-inline-insns" -If an function contains more than this many instructions, it -will not be inlined. This option is precisely equivalent to -\&\fB\-finline-limit\fR. +.IP "\fBmax-inline-insns-single\fR" 4 +.IX Item "max-inline-insns-single" +Several parameters control the tree inliner used in gcc. +This number sets the maximum number of instructions (counted in \s-1GCC\s0's +internal representation) in a single function that the tree inliner +will consider for inlining. This only affects functions declared +inline and methods implemented in a class declaration (\*(C+). +The default value is 500. +.IP "\fBmax-inline-insns-auto\fR" 4 +.IX Item "max-inline-insns-auto" +When you use \fB\-finline\-functions\fR (included in \fB\-O3\fR), +a lot of functions that would otherwise not be considered for inlining +by the compiler will be investigated. To those functions, a different +(more restrictive) limit compared to functions declared inline can +be applied. +The default value is 100. +.IP "\fBlarge-function-insns\fR" 4 +.IX Item "large-function-insns" +The limit specifying really large functions. For functions greater than this +limit inlining is constrained by \fB\-\-param large-function-growth\fR. +This parameter is useful primarily to avoid extreme compilation time caused by non-linear +algorithms used by the backend. +This parameter is ignored when \fB\-funit\-at\-a\-time\fR is not used. +The default value is 3000. +.IP "\fBlarge-function-growth\fR" 4 +.IX Item "large-function-growth" +Specifies maximal growth of large function caused by inlining in percents. +This parameter is ignored when \fB\-funit\-at\-a\-time\fR is not used. +The default value is 200. +.IP "\fBinline-unit-growth\fR" 4 +.IX Item "inline-unit-growth" +Specifies maximal overall growth of the compilation unit caused by inlining. +This parameter is ignored when \fB\-funit\-at\-a\-time\fR is not used. +The default value is 150. +.IP "\fBmax-inline-insns-rtl\fR" 4 +.IX Item "max-inline-insns-rtl" +For languages that use the \s-1RTL\s0 inliner (this happens at a later stage +than tree inlining), you can set the maximum allowable size (counted +in \s-1RTL\s0 instructions) for the \s-1RTL\s0 inliner with this parameter. +The default value is 600. +.IP "\fBmax-unrolled-insns\fR" 4 +.IX Item "max-unrolled-insns" +The maximum number of instructions that a loop should have if that loop +is unrolled, and if the loop is unrolled, it determines how many times +the loop code is unrolled. +.IP "\fBmax-average-unrolled-insns\fR" 4 +.IX Item "max-average-unrolled-insns" +The maximum number of instructions biased by probabilities of their execution +that a loop should have if that loop is unrolled, and if the loop is unrolled, +it determines how many times the loop code is unrolled. +.IP "\fBmax-unroll-times\fR" 4 +.IX Item "max-unroll-times" +The maximum number of unrollings of a single loop. +.IP "\fBmax-peeled-insns\fR" 4 +.IX Item "max-peeled-insns" +The maximum number of instructions that a loop should have if that loop +is peeled, and if the loop is peeled, it determines how many times +the loop code is peeled. +.IP "\fBmax-peel-times\fR" 4 +.IX Item "max-peel-times" +The maximum number of peelings of a single loop. +.IP "\fBmax-completely-peeled-insns\fR" 4 +.IX Item "max-completely-peeled-insns" +The maximum number of insns of a completely peeled loop. +.IP "\fBmax-completely-peel-times\fR" 4 +.IX Item "max-completely-peel-times" +The maximum number of iterations of a loop to be suitable for complete peeling. +.IP "\fBmax-unswitch-insns\fR" 4 +.IX Item "max-unswitch-insns" +The maximum number of insns of an unswitched loop. +.IP "\fBmax-unswitch-level\fR" 4 +.IX Item "max-unswitch-level" +The maximum number of branches unswitched in a single loop. +.IP "\fBhot-bb-count-fraction\fR" 4 +.IX Item "hot-bb-count-fraction" +Select fraction of the maximal count of repetitions of basic block in program +given basic block needs to have to be considered hot. +.IP "\fBhot-bb-frequency-fraction\fR" 4 +.IX Item "hot-bb-frequency-fraction" +Select fraction of the maximal frequency of executions of basic block in +function given basic block needs to have to be considered hot +.IP "\fBtracer-dynamic-coverage\fR" 4 +.IX Item "tracer-dynamic-coverage" +.PD 0 +.IP "\fBtracer-dynamic-coverage-feedback\fR" 4 +.IX Item "tracer-dynamic-coverage-feedback" +.PD +This value is used to limit superblock formation once the given percentage of +executed instructions is covered. This limits unnecessary code size +expansion. +.Sp +The \fBtracer-dynamic-coverage-feedback\fR is used only when profile +feedback is available. The real profiles (as opposed to statically estimated +ones) are much less balanced allowing the threshold to be larger value. +.IP "\fBtracer-max-code-growth\fR" 4 +.IX Item "tracer-max-code-growth" +Stop tail duplication once code growth has reached given percentage. This is +rather hokey argument, as most of the duplicates will be eliminated later in +cross jumping, so it may be set to much higher values than is the desired code +growth. +.IP "\fBtracer-min-branch-ratio\fR" 4 +.IX Item "tracer-min-branch-ratio" +Stop reverse growth when the reverse probability of best edge is less than this +threshold (in percent). +.IP "\fBtracer-min-branch-ratio\fR" 4 +.IX Item "tracer-min-branch-ratio" +.PD 0 +.IP "\fBtracer-min-branch-ratio-feedback\fR" 4 +.IX Item "tracer-min-branch-ratio-feedback" +.PD +Stop forward growth if the best edge do have probability lower than this +threshold. +.Sp +Similarly to \fBtracer-dynamic-coverage\fR two values are present, one for +compilation for profile feedback and one for compilation without. The value +for compilation with profile feedback needs to be more conservative (higher) in +order to make tracer effective. +.IP "\fBmax-cse-path-length\fR" 4 +.IX Item "max-cse-path-length" +Maximum number of basic blocks on path that cse considers. +.IP "\fBmax-last-value-rtl\fR" 4 +.IX Item "max-last-value-rtl" +The maximum size measured as number of RTLs that can be recorded in an +expression in combiner for a pseudo register as last known value of that +register. The default is 10000. +.IP "\fBggc-min-expand\fR" 4 +.IX Item "ggc-min-expand" +\&\s-1GCC\s0 uses a garbage collector to manage its own memory allocation. This +parameter specifies the minimum percentage by which the garbage +collector's heap should be allowed to expand between collections. +Tuning this may improve compilation speed; it has no effect on code +generation. +.Sp +The default is 30% + 70% * (\s-1RAM/1GB\s0) with an upper bound of 100% when +\&\s-1RAM\s0 >= 1GB. If \f(CW\*(C`getrlimit\*(C'\fR is available, the notion of \*(L"\s-1RAM\s0\*(R" is +the smallest of actual \s-1RAM\s0, \s-1RLIMIT_RSS\s0, \s-1RLIMIT_DATA\s0 and \s-1RLIMIT_AS\s0. If +\&\s-1GCC\s0 is not able to calculate \s-1RAM\s0 on a particular platform, the lower +bound of 30% is used. Setting this parameter and +\&\fBggc-min-heapsize\fR to zero causes a full collection to occur at +every opportunity. This is extremely slow, but can be useful for +debugging. +.IP "\fBggc-min-heapsize\fR" 4 +.IX Item "ggc-min-heapsize" +Minimum size of the garbage collector's heap before it begins bothering +to collect garbage. The first collection occurs after the heap expands +by \fBggc-min-expand\fR% beyond \fBggc-min-heapsize\fR. Again, +tuning this may improve compilation speed, and has no effect on code +generation. +.Sp +The default is \s-1RAM/8\s0, with a lower bound of 4096 (four megabytes) and an +upper bound of 131072 (128 megabytes). If \f(CW\*(C`getrlimit\*(C'\fR is +available, the notion of \*(L"\s-1RAM\s0\*(R" is the smallest of actual \s-1RAM\s0, +\&\s-1RLIMIT_RSS\s0, \s-1RLIMIT_DATA\s0 and \s-1RLIMIT_AS\s0. If \s-1GCC\s0 is not able to calculate +\&\s-1RAM\s0 on a particular platform, the lower bound is used. Setting this +parameter very large effectively disables garbage collection. Setting +this parameter and \fBggc-min-expand\fR to zero causes a full +collection to occur at every opportunity. +.IP "\fBmax-reload-search-insns\fR" 4 +.IX Item "max-reload-search-insns" +The maximum number of instruction reload should look backward for equivalent +register. Increasing values mean more aggressive optimization, making the +compile time increase with probably slightly better performance. The default +value is 100. +.IP "\fBmax-cselib-memory-location\fR" 4 +.IX Item "max-cselib-memory-location" +The maximum number of memory locations cselib should take into acount. +Increasing values mean more aggressive optimization, making the compile time +increase with probably slightly better performance. The default value is 500. +.IP "\fBreorder-blocks-duplicate\fR" 4 +.IX Item "reorder-blocks-duplicate" +.PD 0 +.IP "\fBreorder-blocks-duplicate-feedback\fR" 4 +.IX Item "reorder-blocks-duplicate-feedback" +.PD +Used by basic block reordering pass to decide whether to use unconditional +branch or duplicate the code on its destination. Code is duplicated when its +estimated size is smaller than this value multiplied by the estimated size of +unconditional jump in the hot spots of the program. +.Sp +The \fBreorder-block-duplicate-feedback\fR is used only when profile +feedback is available and may be set to higher values than +\&\fBreorder-block-duplicate\fR since information about the hot spots is more +accurate. .RE .RS 4 .RE @@ -3633,7 +4499,8 @@ If you use the \fB\-E\fR option, nothing is done except preprocessing. Some of these options make sense only together with \fB\-E\fR because they cause the preprocessor output to be unsuitable for actual compilation. -.PP +.Sp +.RS 4 You can use \fB\-Wp,\fR\fIoption\fR to bypass the compiler driver and pass \fIoption\fR directly through to the preprocessor. If \&\fIoption\fR contains commas, it is split into multiple options at the @@ -3643,16 +4510,29 @@ by the compiler driver before being passed to the preprocessor, and interface is undocumented and subject to change, so whenever possible you should avoid using \fB\-Wp\fR and let the driver handle the options instead. -.Ip "\fB\-D\fR \fIname\fR" 4 +.RE +.IP "\fB\-Xpreprocessor\fR \fIoption\fR" 4 +.IX Item "-Xpreprocessor option" +Pass \fIoption\fR as an option to the preprocessor. You can use this to +supply system-specific preprocessor options which \s-1GCC\s0 does not know how to +recognize. +.Sp +If you want to pass an option that takes an argument, you must use +\&\fB\-Xpreprocessor\fR twice, once for the option and once for the argument. +.IP "\fB\-D\fR \fIname\fR" 4 .IX Item "-D name" -Predefine \fIname\fR as a macro, with definition \f(CW\*(C`1\*(C'\fR. -.Ip "\fB\-D\fR \fIname\fR\fB=\fR\fIdefinition\fR" 4 +Predefine \fIname\fR as a macro, with definition \f(CW1\fR. +.IP "\fB\-D\fR \fIname\fR\fB=\fR\fIdefinition\fR" 4 .IX Item "-D name=definition" Predefine \fIname\fR as a macro, with definition \fIdefinition\fR. -There are no restrictions on the contents of \fIdefinition\fR, but if -you are invoking the preprocessor from a shell or shell-like program you -may need to use the shell's quoting syntax to protect characters such as -spaces that have a meaning in the shell syntax. +The contents of \fIdefinition\fR are tokenized and processed as if +they appeared during translation phase three in a \fB#define\fR +directive. In particular, the definition will be truncated by +embedded newline characters. +.Sp +If you are invoking the preprocessor from a shell or shell-like +program you may need to use the shell's quoting syntax to protect +characters such as spaces that have a meaning in the shell syntax. .Sp If you wish to define a function-like macro on the command line, write its argument list with surrounding parentheses before the equals sign @@ -3664,89 +4544,131 @@ to quote the option. With \fBsh\fR and \fBcsh\fR, are given on the command line. All \fB\-imacros\fR \fIfile\fR and \&\fB\-include\fR \fIfile\fR options are processed after all \&\fB\-D\fR and \fB\-U\fR options. -.Ip "\fB\-U\fR \fIname\fR" 4 +.IP "\fB\-U\fR \fIname\fR" 4 .IX Item "-U name" Cancel any previous definition of \fIname\fR, either built in or provided with a \fB\-D\fR option. -.Ip "\fB\-undef\fR" 4 +.IP "\fB\-undef\fR" 4 .IX Item "-undef" -Do not predefine any system-specific macros. The common predefined -macros remain defined. -.Ip "\fB\-I\fR \fIdir\fR" 4 +Do not predefine any system-specific or GCC-specific macros. The +standard predefined macros remain defined. +.IP "\fB\-I\fR \fIdir\fR" 4 .IX Item "-I dir" Add the directory \fIdir\fR to the list of directories to be searched for header files. Directories named by \fB\-I\fR are searched before the standard -system include directories. -.Sp -It is dangerous to specify a standard system include directory in an -\&\fB\-I\fR option. This defeats the special treatment of system -headers -\&. It can also defeat the repairs to buggy system headers which \s-1GCC\s0 -makes when it is installed. -.Ip "\fB\-o\fR \fIfile\fR" 4 +system include directories. If the directory \fIdir\fR is a standard +system include directory, the option is ignored to ensure that the +default search order for system directories and the special treatment +of system headers are not defeated +\&. +.IP "\fB\-o\fR \fIfile\fR" 4 .IX Item "-o file" Write output to \fIfile\fR. This is the same as specifying \fIfile\fR as the second non-option argument to \fBcpp\fR. \fBgcc\fR has a different interpretation of a second non-option argument, so you must use \fB\-o\fR to specify the output file. -.Ip "\fB\-Wall\fR" 4 +.IP "\fB\-Wall\fR" 4 .IX Item "-Wall" -Turns on all optional warnings which are desirable for normal code. At -present this is \fB\-Wcomment\fR and \fB\-Wtrigraphs\fR. Note that -many of the preprocessor's warnings are on by default and have no -options to control them. -.Ip "\fB\-Wcomment\fR" 4 +Turns on all optional warnings which are desirable for normal code. +At present this is \fB\-Wcomment\fR, \fB\-Wtrigraphs\fR, +\&\fB\-Wmultichar\fR and a warning about integer promotion causing a +change of sign in \f(CW\*(C`#if\*(C'\fR expressions. Note that many of the +preprocessor's warnings are on by default and have no options to +control them. +.IP "\fB\-Wcomment\fR" 4 .IX Item "-Wcomment" .PD 0 -.Ip "\fB\-Wcomments\fR" 4 +.IP "\fB\-Wcomments\fR" 4 .IX Item "-Wcomments" .PD Warn whenever a comment-start sequence \fB/*\fR appears in a \fB/*\fR comment, or whenever a backslash-newline appears in a \fB//\fR comment. (Both forms have the same effect.) -.Ip "\fB\-Wtrigraphs\fR" 4 +.IP "\fB\-Wtrigraphs\fR" 4 .IX Item "-Wtrigraphs" -Warn if any trigraphs are encountered. This option used to take effect -only if \fB\-trigraphs\fR was also specified, but now works -independently. Warnings are not given for trigraphs within comments, as -they do not affect the meaning of the program. -.Ip "\fB\-Wtraditional\fR" 4 +@anchor{Wtrigraphs} +Most trigraphs in comments cannot affect the meaning of the program. +However, a trigraph that would form an escaped newline (\fB??/\fR at +the end of a line) can, by changing where the comment begins or ends. +Therefore, only trigraphs that would form escaped newlines produce +warnings inside a comment. +.Sp +This option is implied by \fB\-Wall\fR. If \fB\-Wall\fR is not +given, this option is still enabled unless trigraphs are enabled. To +get trigraph conversion without warnings, but get the other +\&\fB\-Wall\fR warnings, use \fB\-trigraphs \-Wall \-Wno\-trigraphs\fR. +.IP "\fB\-Wtraditional\fR" 4 .IX Item "-Wtraditional" Warn about certain constructs that behave differently in traditional and \&\s-1ISO\s0 C. Also warn about \s-1ISO\s0 C constructs that have no traditional C equivalent, and problematic constructs which should be avoided. -.Ip "\fB\-Wimport\fR" 4 +.IP "\fB\-Wimport\fR" 4 .IX Item "-Wimport" Warn the first time \fB#import\fR is used. -.Ip "\fB\-Wundef\fR" 4 +.IP "\fB\-Wundef\fR" 4 .IX Item "-Wundef" Warn whenever an identifier which is not a macro is encountered in an \&\fB#if\fR directive, outside of \fBdefined\fR. Such identifiers are replaced with zero. -.Ip "\fB\-Werror\fR" 4 +.IP "\fB\-Wunused\-macros\fR" 4 +.IX Item "-Wunused-macros" +Warn about macros defined in the main file that are unused. A macro +is \fIused\fR if it is expanded or tested for existence at least once. +The preprocessor will also warn if the macro has not been used at the +time it is redefined or undefined. +.Sp +Built-in macros, macros defined on the command line, and macros +defined in include files are not warned about. +.Sp +\&\fBNote:\fR If a macro is actually used, but only used in skipped +conditional blocks, then \s-1CPP\s0 will report it as unused. To avoid the +warning in such a case, you might improve the scope of the macro's +definition by, for example, moving it into the first skipped block. +Alternatively, you could provide a dummy use with something like: +.Sp +.Vb 2 +\& #if defined the_macro_causing_the_warning +\& #endif +.Ve +.IP "\fB\-Wendif\-labels\fR" 4 +.IX Item "-Wendif-labels" +Warn whenever an \fB#else\fR or an \fB#endif\fR are followed by text. +This usually happens in code of the form +.Sp +.Vb 5 +\& #if FOO +\& ... +\& #else FOO +\& ... +\& #endif FOO +.Ve +.Sp +The second and third \f(CW\*(C`FOO\*(C'\fR should be in comments, but often are not +in older programs. This warning is on by default. +.IP "\fB\-Werror\fR" 4 .IX Item "-Werror" Make all warnings into hard errors. Source code which triggers warnings will be rejected. -.Ip "\fB\-Wsystem-headers\fR" 4 +.IP "\fB\-Wsystem\-headers\fR" 4 .IX Item "-Wsystem-headers" Issue warnings for code in system headers. These are normally unhelpful in finding bugs in your own code, therefore suppressed. If you are responsible for the system library, you may want to see them. -.Ip "\fB\-w\fR" 4 +.IP "\fB\-w\fR" 4 .IX Item "-w" Suppress all warnings, including those which \s-1GNU\s0 \s-1CPP\s0 issues by default. -.Ip "\fB\-pedantic\fR" 4 +.IP "\fB\-pedantic\fR" 4 .IX Item "-pedantic" Issue all the mandatory diagnostics listed in the C standard. Some of them are left out by default, since they trigger frequently on harmless code. -.Ip "\fB\-pedantic-errors\fR" 4 +.IP "\fB\-pedantic\-errors\fR" 4 .IX Item "-pedantic-errors" Issue all the mandatory diagnostics, and make all mandatory diagnostics into errors. This includes mandatory diagnostics that \s-1GCC\s0 issues without \fB\-pedantic\fR but treats as warnings. -.Ip "\fB\-M\fR" 4 +.IP "\fB\-M\fR" 4 .IX Item "-M" Instead of outputting the result of preprocessing, output a rule suitable for \fBmake\fR describing the dependencies of the main @@ -3768,8 +4690,9 @@ rules you should explicitly specify the dependency output file with \&\fB\s-1DEPENDENCIES_OUTPUT\s0\fR. Debug output will still be sent to the regular output stream as normal. .Sp -Passing \fB\-M\fR to the driver implies \fB\-E\fR. -.Ip "\fB\-MM\fR" 4 +Passing \fB\-M\fR to the driver implies \fB\-E\fR, and suppresses +warnings with an implicit \fB\-w\fR. +.IP "\fB\-MM\fR" 4 .IX Item "-MM" Like \fB\-M\fR but do not mention header files that are found in system header directories, nor header files that are included, @@ -3779,9 +4702,10 @@ This implies that the choice of angle brackets or double quotes in an \&\fB#include\fR directive does not in itself determine whether that header will appear in \fB\-MM\fR dependency output. This is a slight change in semantics from \s-1GCC\s0 versions 3.0 and earlier. -.Ip "\fB\-MF\fR \fIfile\fR" 4 +.Sp +@anchor{dashMF} +.IP "\fB\-MF\fR \fIfile\fR" 4 .IX Item "-MF file" -@anchor{\-MF} When used with \fB\-M\fR or \fB\-MM\fR, specifies a file to write the dependencies to. If no \fB\-MF\fR switch is given the preprocessor sends the rules to the same place it would have sent @@ -3789,15 +4713,18 @@ preprocessed output. .Sp When used with the driver options \fB\-MD\fR or \fB\-MMD\fR, \&\fB\-MF\fR overrides the default dependency output file. -.Ip "\fB\-MG\fR" 4 +.IP "\fB\-MG\fR" 4 .IX Item "-MG" -When used with \fB\-M\fR or \fB\-MM\fR, \fB\-MG\fR says to treat missing -header files as generated files and assume they live in the same -directory as the source file. It suppresses preprocessed output, as a -missing header file is ordinarily an error. +In conjunction with an option such as \fB\-M\fR requesting +dependency generation, \fB\-MG\fR assumes missing header files are +generated files and adds them to the dependency list without raising +an error. The dependency filename is taken directly from the +\&\f(CW\*(C`#include\*(C'\fR directive without prepending any path. \fB\-MG\fR +also suppresses preprocessed output, as a missing header file renders +this useless. .Sp This feature is used in automatic updating of makefiles. -.Ip "\fB\-MP\fR" 4 +.IP "\fB\-MP\fR" 4 .IX Item "-MP" This option instructs \s-1CPP\s0 to add a phony target for each dependency other than the main file, causing each to depend on nothing. These @@ -3809,10 +4736,11 @@ This is typical output: .Vb 1 \& test.o: test.c test.h .Ve +.Sp .Vb 1 \& test.h: .Ve -.Ip "\fB\-MT\fR \fItarget\fR" 4 +.IP "\fB\-MT\fR \fItarget\fR" 4 .IX Item "-MT target" Change the target of the rule emitted by dependency generation. By default \s-1CPP\s0 takes the name of the main input file, including any path, @@ -3828,7 +4756,7 @@ For example, \fB\-MT\ '$(objpfx)foo.o'\fR might give .Vb 1 \& $(objpfx)foo.o: foo.c .Ve -.Ip "\fB\-MQ\fR \fItarget\fR" 4 +.IP "\fB\-MQ\fR \fItarget\fR" 4 .IX Item "-MQ target" Same as \fB\-MT\fR, but it quotes any characters which are special to Make. \fB\-MQ\ '$(objpfx)foo.o'\fR gives @@ -3836,9 +4764,10 @@ Make. \fB\-MQ\ '$(objpfx)foo.o'\fR gives .Vb 1 \& $$(objpfx)foo.o: foo.c .Ve +.Sp The default target is automatically quoted, as if it were given with \&\fB\-MQ\fR. -.Ip "\fB\-MD\fR" 4 +.IP "\fB\-MD\fR" 4 .IX Item "-MD" \&\fB\-MD\fR is equivalent to \fB\-M \-MF\fR \fIfile\fR, except that \&\fB\-E\fR is not implied. The driver determines \fIfile\fR based on @@ -3848,26 +4777,34 @@ basename of the input file and applies a \fI.d\fR suffix. .Sp If \fB\-MD\fR is used in conjunction with \fB\-E\fR, any \&\fB\-o\fR switch is understood to specify the dependency output file -(but \f(CW@pxref\fR{\-MF}), but if used without \fB\-E\fR, each \fB\-o\fR +(but \f(CW@pxref\fR{dashMF,,\-MF}), but if used without \fB\-E\fR, each \fB\-o\fR is understood to specify a target object file. .Sp Since \fB\-E\fR is not implied, \fB\-MD\fR can be used to generate a dependency output file as a side-effect of the compilation process. -.Ip "\fB\-MMD\fR" 4 +.IP "\fB\-MMD\fR" 4 .IX Item "-MMD" Like \fB\-MD\fR except mention only user header files, not system \&\-header files. -.Ip "\fB\-x c\fR" 4 +.IP "\fB\-fpch\-deps\fR" 4 +.IX Item "-fpch-deps" +When using precompiled headers, this flag +will cause the dependency-output flags to also list the files from the +precompiled header's dependencies. If not specified only the +precompiled header would be listed and not the files that were used to +create it because those files are not consulted when a precompiled +header is used. +.IP "\fB\-x c\fR" 4 .IX Item "-x c" .PD 0 -.Ip "\fB\-x c++\fR" 4 +.IP "\fB\-x c++\fR" 4 .IX Item "-x c++" -.Ip "\fB\-x objective-c\fR" 4 +.IP "\fB\-x objective-c\fR" 4 .IX Item "-x objective-c" -.Ip "\fB\-x assembler-with-cpp\fR" 4 +.IP "\fB\-x assembler-with-cpp\fR" 4 .IX Item "-x assembler-with-cpp" .PD -Specify the source language: C, \*(C+, Objective-C, or assembly. This has +Specify the source language: C, \*(C+, Objective\-C, or assembly. This has nothing to do with standards conformance or extensions; it merely selects which base syntax to expect. If you give none of these options, cpp will deduce the language from the extension of the source file: @@ -3880,89 +4817,97 @@ generic mode. which selected both the language and the standards conformance level. This option has been removed, because it conflicts with the \fB\-l\fR option. -.Ip "\fB\-std=\fR\fIstandard\fR" 4 +.IP "\fB\-std=\fR\fIstandard\fR" 4 .IX Item "-std=standard" .PD 0 -.Ip "\fB\-ansi\fR" 4 +.IP "\fB\-ansi\fR" 4 .IX Item "-ansi" .PD -Specify the standard to which the code should conform. Currently cpp -only knows about the standards for C; other language standards will be -added in the future. +Specify the standard to which the code should conform. Currently \s-1CPP\s0 +knows about C and \*(C+ standards; others may be added in the future. .Sp \&\fIstandard\fR may be one of: .RS 4 -.if n .Ip "\f(CW""""iso9899:1990""""\fR" 4 -.el .Ip "\f(CWiso9899:1990\fR" 4 +.ie n .IP """iso9899:1990""" 4 +.el .IP "\f(CWiso9899:1990\fR" 4 .IX Item "iso9899:1990" .PD 0 -.if n .Ip "\f(CW""""c89""""\fR" 4 -.el .Ip "\f(CWc89\fR" 4 +.ie n .IP """c89""" 4 +.el .IP "\f(CWc89\fR" 4 .IX Item "c89" .PD The \s-1ISO\s0 C standard from 1990. \fBc89\fR is the customary shorthand for this version of the standard. .Sp The \fB\-ansi\fR option is equivalent to \fB\-std=c89\fR. -.if n .Ip "\f(CW""""iso9899:199409""""\fR" 4 -.el .Ip "\f(CWiso9899:199409\fR" 4 +.ie n .IP """iso9899:199409""" 4 +.el .IP "\f(CWiso9899:199409\fR" 4 .IX Item "iso9899:199409" The 1990 C standard, as amended in 1994. -.if n .Ip "\f(CW""""iso9899:1999""""\fR" 4 -.el .Ip "\f(CWiso9899:1999\fR" 4 +.ie n .IP """iso9899:1999""" 4 +.el .IP "\f(CWiso9899:1999\fR" 4 .IX Item "iso9899:1999" .PD 0 -.if n .Ip "\f(CW""""c99""""\fR" 4 -.el .Ip "\f(CWc99\fR" 4 +.ie n .IP """c99""" 4 +.el .IP "\f(CWc99\fR" 4 .IX Item "c99" -.if n .Ip "\f(CW""""iso9899:199x""""\fR" 4 -.el .Ip "\f(CWiso9899:199x\fR" 4 +.ie n .IP """iso9899:199x""" 4 +.el .IP "\f(CWiso9899:199x\fR" 4 .IX Item "iso9899:199x" -.if n .Ip "\f(CW""""c9x""""\fR" 4 -.el .Ip "\f(CWc9x\fR" 4 +.ie n .IP """c9x""" 4 +.el .IP "\f(CWc9x\fR" 4 .IX Item "c9x" .PD The revised \s-1ISO\s0 C standard, published in December 1999. Before publication, this was known as C9X. -.if n .Ip "\f(CW""""gnu89""""\fR" 4 -.el .Ip "\f(CWgnu89\fR" 4 +.ie n .IP """gnu89""" 4 +.el .IP "\f(CWgnu89\fR" 4 .IX Item "gnu89" The 1990 C standard plus \s-1GNU\s0 extensions. This is the default. -.if n .Ip "\f(CW""""gnu99""""\fR" 4 -.el .Ip "\f(CWgnu99\fR" 4 +.ie n .IP """gnu99""" 4 +.el .IP "\f(CWgnu99\fR" 4 .IX Item "gnu99" .PD 0 -.if n .Ip "\f(CW""""gnu9x""""\fR" 4 -.el .Ip "\f(CWgnu9x\fR" 4 +.ie n .IP """gnu9x""" 4 +.el .IP "\f(CWgnu9x\fR" 4 .IX Item "gnu9x" .PD The 1999 C standard plus \s-1GNU\s0 extensions. +.ie n .IP """c++98""" 4 +.el .IP "\f(CWc++98\fR" 4 +.IX Item "c++98" +The 1998 \s-1ISO\s0 \*(C+ standard plus amendments. +.ie n .IP """gnu++98""" 4 +.el .IP "\f(CWgnu++98\fR" 4 +.IX Item "gnu++98" +The same as \fB\-std=c++98\fR plus \s-1GNU\s0 extensions. This is the +default for \*(C+ code. .RE .RS 4 .RE -.Ip "\fB\-I-\fR" 4 +.IP "\fB\-I\-\fR" 4 .IX Item "-I-" Split the include path. Any directories specified with \fB\-I\fR -options before \fB\-I-\fR are searched only for headers requested with +options before \fB\-I\-\fR are searched only for headers requested with \&\f(CW\*(C`#include\ "\f(CIfile\f(CW"\*(C'\fR; they are not searched for \&\f(CW\*(C`#include\ <\f(CIfile\f(CW>\*(C'\fR. If additional directories are -specified with \fB\-I\fR options after the \fB\-I-\fR, those +specified with \fB\-I\fR options after the \fB\-I\-\fR, those directories are searched for all \fB#include\fR directives. .Sp -In addition, \fB\-I-\fR inhibits the use of the directory of the current +In addition, \fB\-I\-\fR inhibits the use of the directory of the current file directory as the first search directory for \f(CW\*(C`#include\ "\f(CIfile\f(CW"\*(C'\fR. -.Ip "\fB\-nostdinc\fR" 4 +.IP "\fB\-nostdinc\fR" 4 .IX Item "-nostdinc" Do not search the standard system directories for header files. Only the directories you have specified with \fB\-I\fR options (and the directory of the current file, if appropriate) are searched. -.Ip "\fB\-nostdinc++\fR" 4 +.IP "\fB\-nostdinc++\fR" 4 .IX Item "-nostdinc++" Do not search for header files in the \*(C+\-specific standard directories, but do still search the other standard directories. (This option is used when building the \*(C+ library.) -.Ip "\fB\-include\fR \fIfile\fR" 4 +.IP "\fB\-include\fR \fIfile\fR" 4 .IX Item "-include file" Process \fIfile\fR as if \f(CW\*(C`#include "file"\*(C'\fR appeared as the first line of the primary source file. However, the first directory searched @@ -3973,7 +4918,7 @@ chain as normal. .Sp If multiple \fB\-include\fR options are given, the files are included in the order they appear on the command line. -.Ip "\fB\-imacros\fR \fIfile\fR" 4 +.IP "\fB\-imacros\fR \fIfile\fR" 4 .IX Item "-imacros file" Exactly like \fB\-include\fR, except that any output produced by scanning \fIfile\fR is thrown away. Macros it defines remain defined. @@ -3982,35 +4927,37 @@ processing its declarations. .Sp All files specified by \fB\-imacros\fR are processed before all files specified by \fB\-include\fR. -.Ip "\fB\-idirafter\fR \fIdir\fR" 4 +.IP "\fB\-idirafter\fR \fIdir\fR" 4 .IX Item "-idirafter dir" Search \fIdir\fR for header files, but do it \fIafter\fR all directories specified with \fB\-I\fR and the standard system directories have been exhausted. \fIdir\fR is treated as a system include directory. -.Ip "\fB\-iprefix\fR \fIprefix\fR" 4 +.IP "\fB\-iprefix\fR \fIprefix\fR" 4 .IX Item "-iprefix prefix" Specify \fIprefix\fR as the prefix for subsequent \fB\-iwithprefix\fR options. If the prefix represents a directory, you should include the final \fB/\fR. -.Ip "\fB\-iwithprefix\fR \fIdir\fR" 4 +.IP "\fB\-iwithprefix\fR \fIdir\fR" 4 .IX Item "-iwithprefix dir" .PD 0 -.Ip "\fB\-iwithprefixbefore\fR \fIdir\fR" 4 +.IP "\fB\-iwithprefixbefore\fR \fIdir\fR" 4 .IX Item "-iwithprefixbefore dir" .PD Append \fIdir\fR to the prefix specified previously with \&\fB\-iprefix\fR, and add the resulting directory to the include search path. \fB\-iwithprefixbefore\fR puts it in the same place \fB\-I\fR would; \fB\-iwithprefix\fR puts it where \fB\-idirafter\fR would. -.Sp -Use of these options is discouraged. -.Ip "\fB\-isystem\fR \fIdir\fR" 4 +.IP "\fB\-isystem\fR \fIdir\fR" 4 .IX Item "-isystem dir" Search \fIdir\fR for header files, after all directories specified by \&\fB\-I\fR but before the standard system directories. Mark it as a system directory, so that it gets the same special treatment as is applied to the standard system directories. -.Ip "\fB\-fpreprocessed\fR" 4 +.IP "\fB\-fdollars\-in\-identifiers\fR" 4 +.IX Item "-fdollars-in-identifiers" +@anchor{fdollars\-in\-identifiers} +Accept \fB$\fR in identifiers. +.IP "\fB\-fpreprocessed\fR" 4 .IX Item "-fpreprocessed" Indicate to the preprocessor that the input file has already been preprocessed. This suppresses things like macro expansion, trigraph @@ -4023,35 +4970,65 @@ a tokenizer for the front ends. \&\fB\-fpreprocessed\fR is implicit if the input file has one of the extensions \fB.i\fR, \fB.ii\fR or \fB.mi\fR. These are the extensions that \s-1GCC\s0 uses for preprocessed files created by -\&\fB\-save-temps\fR. -.Ip "\fB\-ftabstop=\fR\fIwidth\fR" 4 +\&\fB\-save\-temps\fR. +.IP "\fB\-ftabstop=\fR\fIwidth\fR" 4 .IX Item "-ftabstop=width" Set the distance between tab stops. This helps the preprocessor report correct column numbers in warnings or errors, even if tabs appear on the line. If the value is less than 1 or greater than 100, the option is ignored. The default is 8. -.Ip "\fB\-fno-show-column\fR" 4 +.IP "\fB\-fexec\-charset=\fR\fIcharset\fR" 4 +.IX Item "-fexec-charset=charset" +Set the execution character set, used for string and character +constants. The default is \s-1UTF\-8\s0. \fIcharset\fR can be any encoding +supported by the system's \f(CW\*(C`iconv\*(C'\fR library routine. +.IP "\fB\-fwide\-exec\-charset=\fR\fIcharset\fR" 4 +.IX Item "-fwide-exec-charset=charset" +Set the wide execution character set, used for wide string and +character constants. The default is \s-1UTF\-32\s0 or \s-1UTF\-16\s0, whichever +corresponds to the width of \f(CW\*(C`wchar_t\*(C'\fR. As with +\&\fB\-ftarget\-charset\fR, \fIcharset\fR can be any encoding supported +by the system's \f(CW\*(C`iconv\*(C'\fR library routine; however, you will have +problems with encodings that do not fit exactly in \f(CW\*(C`wchar_t\*(C'\fR. +.IP "\fB\-finput\-charset=\fR\fIcharset\fR" 4 +.IX Item "-finput-charset=charset" +Set the input character set, used for translation from the character +set of the input file to the source character set used by \s-1GCC\s0. If the +locale does not specify, or \s-1GCC\s0 cannot get this information from the +locale, the default is \s-1UTF\-8\s0. This can be overridden by either the locale +or this command line option. Currently the command line option takes +precedence if there's a conflict. \fIcharset\fR can be any encoding +supported by the system's \f(CW\*(C`iconv\*(C'\fR library routine. +.IP "\fB\-fworking\-directory\fR" 4 +.IX Item "-fworking-directory" +Enable generation of linemarkers in the preprocessor output that will +let the compiler know the current working directory at the time of +preprocessing. When this option is enabled, the preprocessor will +emit, after the initial linemarker, a second linemarker with the +current working directory followed by two slashes. \s-1GCC\s0 will use this +directory, when it's present in the preprocessed input, as the +directory emitted as the current working directory in some debugging +information formats. This option is implicitly enabled if debugging +information is enabled, but this can be inhibited with the negated +form \fB\-fno\-working\-directory\fR. If the \fB\-P\fR flag is +present in the command line, this option has no effect, since no +\&\f(CW\*(C`#line\*(C'\fR directives are emitted whatsoever. +.IP "\fB\-fno\-show\-column\fR" 4 .IX Item "-fno-show-column" Do not print column numbers in diagnostics. This may be necessary if diagnostics are being scanned by a program that does not understand the column numbers, such as \fBdejagnu\fR. -.Ip "\fB\-A\fR \fIpredicate\fR\fB=\fR\fIanswer\fR" 4 +.IP "\fB\-A\fR \fIpredicate\fR\fB=\fR\fIanswer\fR" 4 .IX Item "-A predicate=answer" Make an assertion with the predicate \fIpredicate\fR and answer \&\fIanswer\fR. This form is preferred to the older form \fB\-A\fR \&\fIpredicate\fR\fB(\fR\fIanswer\fR\fB)\fR, which is still supported, because it does not use shell special characters. -.Ip "\fB\-A -\fR\fIpredicate\fR\fB=\fR\fIanswer\fR" 4 +.IP "\fB\-A \-\fR\fIpredicate\fR\fB=\fR\fIanswer\fR" 4 .IX Item "-A -predicate=answer" Cancel an assertion with the predicate \fIpredicate\fR and answer \&\fIanswer\fR. -.Ip "\fB\-A-\fR" 4 -.IX Item "-A-" -Cancel all predefined assertions and all assertions preceding it on -the command line. Also, undefine all predefined macros and all -macros preceding it on the command line. (This is a historical wart and -may change in the future.) -.Ip "\fB\-dCHARS\fR" 4 +.IP "\fB\-dCHARS\fR" 4 .IX Item "-dCHARS" \&\fI\s-1CHARS\s0\fR is a sequence of one or more of the following characters, and must not be preceded by a space. Other characters are interpreted @@ -4059,7 +5036,7 @@ by the compiler proper, or reserved for future versions of \s-1GCC\s0, and so are silently ignored. If you specify characters whose behavior conflicts, the result is undefined. .RS 4 -.Ip "\fBM\fR" 4 +.IP "\fBM\fR" 4 .IX Item "M" Instead of the normal output, generate a list of \fB#define\fR directives for all the macros defined during the execution of the @@ -4070,30 +5047,31 @@ Assuming you have no file \fIfoo.h\fR, the command .Vb 1 \& touch foo.h; cpp -dM foo.h .Ve +.Sp will show all the predefined macros. -.Ip "\fBD\fR" 4 +.IP "\fBD\fR" 4 .IX Item "D" Like \fBM\fR except in two respects: it does \fInot\fR include the predefined macros, and it outputs \fIboth\fR the \fB#define\fR directives and the result of preprocessing. Both kinds of output go to the standard output file. -.Ip "\fBN\fR" 4 +.IP "\fBN\fR" 4 .IX Item "N" Like \fBD\fR, but emit only the macro names, not their expansions. -.Ip "\fBI\fR" 4 +.IP "\fBI\fR" 4 .IX Item "I" Output \fB#include\fR directives in addition to the result of preprocessing. .RE .RS 4 .RE -.Ip "\fB\-P\fR" 4 +.IP "\fB\-P\fR" 4 .IX Item "-P" Inhibit generation of linemarkers in the output from the preprocessor. This might be useful when running the preprocessor on something that is not C code, and will be sent to a program which might be confused by the linemarkers. -.Ip "\fB\-C\fR" 4 +.IP "\fB\-C\fR" 4 .IX Item "-C" Do not discard comments. All comments are passed through to the output file, except for comments in processed directives, which are deleted @@ -4104,17 +5082,24 @@ causes the preprocessor to treat comments as tokens in their own right. For example, comments appearing at the start of what would be a directive line have the effect of turning that line into an ordinary source line, since the first token on the line is no longer a \fB#\fR. -.Ip "\fB\-gcc\fR" 4 -.IX Item "-gcc" -Define the macros _\|_GNUC_\|_, _\|_GNUC_MINOR_\|_ and -_\|_GNUC_PATCHLEVEL_\|_. These are defined automatically when you use -\&\fBgcc \-E\fR; you can turn them off in that case with -\&\fB\-no-gcc\fR. -.Ip "\fB\-traditional\fR" 4 -.IX Item "-traditional" -Try to imitate the behavior of old-fashioned C, as opposed to \s-1ISO\s0 -C. -.Ip "\fB\-trigraphs\fR" 4 +.IP "\fB\-CC\fR" 4 +.IX Item "-CC" +Do not discard comments, including during macro expansion. This is +like \fB\-C\fR, except that comments contained within macros are +also passed through to the output file where the macro is expanded. +.Sp +In addition to the side-effects of the \fB\-C\fR option, the +\&\fB\-CC\fR option causes all \*(C+\-style comments inside a macro +to be converted to C\-style comments. This is to prevent later use +of that macro from inadvertently commenting out the remainder of +the source line. +.Sp +The \fB\-CC\fR option is generally used to support lint comments. +.IP "\fB\-traditional\-cpp\fR" 4 +.IX Item "-traditional-cpp" +Try to imitate the behavior of old-fashioned C preprocessors, as +opposed to \s-1ISO\s0 C preprocessors. +.IP "\fB\-trigraphs\fR" 4 .IX Item "-trigraphs" Process trigraph sequences. These are three-character sequences, all starting with \fB??\fR, that @@ -4130,75 +5115,78 @@ The nine trigraphs and their replacements are \& Trigraph: ??( ??) ??< ??> ??= ??/ ??' ??! ??- \& Replacement: [ ] { } # \e ^ | ~ .Ve -.Ip "\fB\-remap\fR" 4 +.IP "\fB\-remap\fR" 4 .IX Item "-remap" Enable special code to work around file systems which only permit very -short file names, such as \s-1MS-DOS\s0. -.Ip "\fB\-$\fR" 4 -.IX Item "-$" -Forbid the use of \fB$\fR in identifiers. The C standard allows -implementations to define extra characters that can appear in -identifiers. By default \s-1GNU\s0 \s-1CPP\s0 permits \fB$\fR, a common extension. -.Ip "\fB\-h\fR" 4 -.IX Item "-h" -.PD 0 -.Ip "\fB\*(--help\fR" 4 -.IX Item "help" -.Ip "\fB\*(--target-help\fR" 4 -.IX Item "target-help" +short file names, such as \s-1MS\-DOS\s0. +.IP "\fB\-\-help\fR" 4 +.IX Item "--help" +.PD 0 +.IP "\fB\-\-target\-help\fR" 4 +.IX Item "--target-help" .PD Print text describing all the command line options instead of preprocessing anything. -.Ip "\fB\-v\fR" 4 +.IP "\fB\-v\fR" 4 .IX Item "-v" Verbose mode. Print out \s-1GNU\s0 \s-1CPP\s0's version number at the beginning of execution, and report the final form of the include path. -.Ip "\fB\-H\fR" 4 +.IP "\fB\-H\fR" 4 .IX Item "-H" Print the name of each header file used, in addition to other normal activities. Each name is indented to show how deep in the -\&\fB#include\fR stack it is. -.Ip "\fB\-version\fR" 4 +\&\fB#include\fR stack it is. Precompiled header files are also +printed, even if they are found to be invalid; an invalid precompiled +header file is printed with \fB...x\fR and a valid one with \fB...!\fR . +.IP "\fB\-version\fR" 4 .IX Item "-version" .PD 0 -.Ip "\fB\*(--version\fR" 4 -.IX Item "version" +.IP "\fB\-\-version\fR" 4 +.IX Item "--version" .PD Print out \s-1GNU\s0 \s-1CPP\s0's version number. With one dash, proceed to preprocess as normal. With two dashes, exit immediately. .Sh "Passing Options to the Assembler" .IX Subsection "Passing Options to the Assembler" You can pass options to the assembler. -.Ip "\fB\-Wa,\fR\fIoption\fR" 4 +.IP "\fB\-Wa,\fR\fIoption\fR" 4 .IX Item "-Wa,option" Pass \fIoption\fR as an option to the assembler. If \fIoption\fR contains commas, it is split into multiple options at the commas. +.IP "\fB\-Xassembler\fR \fIoption\fR" 4 +.IX Item "-Xassembler option" +Pass \fIoption\fR as an option to the assembler. You can use this to +supply system-specific assembler options which \s-1GCC\s0 does not know how to +recognize. +.Sp +If you want to pass an option that takes an argument, you must use +\&\fB\-Xassembler\fR twice, once for the option and once for the argument. .Sh "Options for Linking" .IX Subsection "Options for Linking" These options come into play when the compiler links object files into an executable output file. They are meaningless if the compiler is not doing a link step. -.Ip "\fIobject-file-name\fR" 4 +.IP "\fIobject-file-name\fR" 4 .IX Item "object-file-name" A file name that does not end in a special recognized suffix is considered to name an object file or library. (Object files are distinguished from libraries by the linker according to the file contents.) If linking is done, these object files are used as input to the linker. -.Ip "\fB\-c\fR" 4 +.IP "\fB\-c\fR" 4 .IX Item "-c" .PD 0 -.Ip "\fB\-S\fR" 4 +.IP "\fB\-S\fR" 4 .IX Item "-S" -.Ip "\fB\-E\fR" 4 +.IP "\fB\-E\fR" 4 .IX Item "-E" .PD If any of these options is used, then the linker is not run, and object file names should not be used as arguments. -.Ip "\fB\-l\fR\fIlibrary\fR" 4 +.IP "\fB\-l\fR\fIlibrary\fR" 4 .IX Item "-llibrary" .PD 0 -.Ip "\fB\-l\fR \fIlibrary\fR" 4 +.IP "\fB\-l\fR \fIlibrary\fR" 4 .IX Item "-l library" .PD Search the library named \fIlibrary\fR when linking. (The second @@ -4226,16 +5214,16 @@ ordinary object file, it is linked in the usual fashion. The only difference between using an \fB\-l\fR option and specifying a file name is that \fB\-l\fR surrounds \fIlibrary\fR with \fBlib\fR and \fB.a\fR and searches several directories. -.Ip "\fB\-lobjc\fR" 4 +.IP "\fB\-lobjc\fR" 4 .IX Item "-lobjc" You need this special case of the \fB\-l\fR option in order to link an Objective-C program. -.Ip "\fB\-nostartfiles\fR" 4 +.IP "\fB\-nostartfiles\fR" 4 .IX Item "-nostartfiles" Do not use the standard system startup files when linking. The standard system libraries are used normally, unless \fB\-nostdlib\fR or \fB\-nodefaultlibs\fR is used. -.Ip "\fB\-nodefaultlibs\fR" 4 +.IP "\fB\-nodefaultlibs\fR" 4 .IX Item "-nodefaultlibs" Do not use the standard system libraries when linking. Only the libraries you specify will be passed to the linker. @@ -4245,7 +5233,7 @@ for System V (and \s-1ISO\s0 C) environments or to bcopy and bzero for \&\s-1BSD\s0 environments. These entries are usually resolved by entries in libc. These entry points should be supplied through some other mechanism when this option is specified. -.Ip "\fB\-nostdlib\fR" 4 +.IP "\fB\-nostdlib\fR" 4 .IX Item "-nostdlib" Do not use the standard system startup files or libraries when linking. No startup files and only the libraries you specify will be passed to @@ -4266,24 +5254,30 @@ or \fB\-nodefaultlibs\fR you should usually specify \fB\-lgcc\fR as well. This ensures that you have no unresolved references to internal \s-1GCC\s0 library subroutines. (For example, \fB_\|_main\fR, used to ensure \*(C+ constructors will be called.) -.Ip "\fB\-s\fR" 4 +.IP "\fB\-pie\fR" 4 +.IX Item "-pie" +Produce a position independent executable on targets which support it. +For predictable results, you must also specify the same set of options +that were used to generate code (\fB\-fpie\fR, \fB\-fPIE\fR, +or model suboptions) when you specify this option. +.IP "\fB\-s\fR" 4 .IX Item "-s" Remove all symbol table and relocation information from the executable. -.Ip "\fB\-static\fR" 4 +.IP "\fB\-static\fR" 4 .IX Item "-static" On systems that support dynamic linking, this prevents linking with the shared libraries. On other systems, this option has no effect. -.Ip "\fB\-shared\fR" 4 +.IP "\fB\-shared\fR" 4 .IX Item "-shared" Produce a shared object which can then be linked with other objects to form an executable. Not all systems support this option. For predictable results, you must also specify the same set of options that were used to generate code (\fB\-fpic\fR, \fB\-fPIC\fR, or model suboptions) when you specify this option.[1] -.Ip "\fB\-shared-libgcc\fR" 4 +.IP "\fB\-shared\-libgcc\fR" 4 .IX Item "-shared-libgcc" .PD 0 -.Ip "\fB\-static-libgcc\fR" 4 +.IP "\fB\-static\-libgcc\fR" 4 .IX Item "-static-libgcc" .PD On systems that provide \fIlibgcc\fR as a shared library, these options @@ -4298,33 +5292,33 @@ across different shared libraries. In that case, each of the libraries as well as the application itself should use the shared \fIlibgcc\fR. .Sp Therefore, the G++ and \s-1GCJ\s0 drivers automatically add -\&\fB\-shared-libgcc\fR whenever you build a shared library or a main +\&\fB\-shared\-libgcc\fR whenever you build a shared library or a main executable, because \*(C+ and Java programs typically use exceptions, so this is the right thing to do. .Sp If, instead, you use the \s-1GCC\s0 driver to create shared libraries, you may find that they will not always be linked with the shared \fIlibgcc\fR. -If \s-1GCC\s0 finds, at its configuration time, that you have a \s-1GNU\s0 linker that -does not support option \fB\*(--eh-frame-hdr\fR, it will link the shared -version of \fIlibgcc\fR into shared libraries by default. Otherwise, -it will take advantage of the linker and optimize away the linking with -the shared version of \fIlibgcc\fR, linking with the static version of -libgcc by default. This allows exceptions to propagate through such -shared libraries, without incurring relocation costs at library load -time. +If \s-1GCC\s0 finds, at its configuration time, that you have a non-GNU linker +or a \s-1GNU\s0 linker that does not support option \fB\-\-eh\-frame\-hdr\fR, +it will link the shared version of \fIlibgcc\fR into shared libraries +by default. Otherwise, it will take advantage of the linker and optimize +away the linking with the shared version of \fIlibgcc\fR, linking with +the static version of libgcc by default. This allows exceptions to +propagate through such shared libraries, without incurring relocation +costs at library load time. .Sp However, if a library or main executable is supposed to throw or catch exceptions, you must link it using the G++ or \s-1GCJ\s0 driver, as appropriate for the languages used in the program, or using the option -\&\fB\-shared-libgcc\fR, such that it is linked with the shared +\&\fB\-shared\-libgcc\fR, such that it is linked with the shared \&\fIlibgcc\fR. -.Ip "\fB\-symbolic\fR" 4 +.IP "\fB\-symbolic\fR" 4 .IX Item "-symbolic" Bind references to global symbols when building a shared object. Warn about any unresolved references (unless overridden by the link editor option \fB\-Xlinker \-z \-Xlinker defs\fR). Only a few systems support this option. -.Ip "\fB\-Xlinker\fR \fIoption\fR" 4 +.IP "\fB\-Xlinker\fR \fIoption\fR" 4 .IX Item "-Xlinker option" Pass \fIoption\fR as an option to the linker. You can use this to supply system-specific linker options which \s-1GCC\s0 does not know how to @@ -4336,11 +5330,11 @@ For example, to pass \fB\-assert definitions\fR, you must write \&\fB\-Xlinker \-assert \-Xlinker definitions\fR. It does not work to write \&\fB\-Xlinker \*(L"\-assert definitions\*(R"\fR, because this passes the entire string as a single argument, which is not what the linker expects. -.Ip "\fB\-Wl,\fR\fIoption\fR" 4 +.IP "\fB\-Wl,\fR\fIoption\fR" 4 .IX Item "-Wl,option" Pass \fIoption\fR as an option to the linker. If \fIoption\fR contains commas, it is split into multiple options at the commas. -.Ip "\fB\-u\fR \fIsymbol\fR" 4 +.IP "\fB\-u\fR \fIsymbol\fR" 4 .IX Item "-u symbol" Pretend the symbol \fIsymbol\fR is undefined, to force linking of library modules to define it. You can use \fB\-u\fR multiple times with @@ -4349,7 +5343,7 @@ different symbols to force loading of additional library modules. .IX Subsection "Options for Directory Search" These options specify directories to search for header files, for libraries and for parts of the compiler: -.Ip "\fB\-I\fR\fIdir\fR" 4 +.IP "\fB\-I\fR\fIdir\fR" 4 .IX Item "-Idir" Add the directory \fIdir\fR to the head of the list of directories to be searched for header files. This can be used to override a system header @@ -4365,36 +5359,36 @@ If a standard system include directory, or a directory specified with option will be ignored. The directory will still be searched but as a system directory at its normal position in the system include chain. This is to ensure that \s-1GCC\s0's procedure to fix buggy system headers and -the ordering for the include_next directive are not inadvertantly changed. +the ordering for the include_next directive are not inadvertently changed. If you really need to change the search order for system directories, use the \fB\-nostdinc\fR and/or \fB\-isystem\fR options. -.Ip "\fB\-I-\fR" 4 +.IP "\fB\-I\-\fR" 4 .IX Item "-I-" -Any directories you specify with \fB\-I\fR options before the \fB\-I-\fR +Any directories you specify with \fB\-I\fR options before the \fB\-I\-\fR option are searched only for the case of \fB#include "\fR\fIfile\fR\fB"\fR; they are not searched for \fB#include <\fR\fIfile\fR\fB>\fR. .Sp If additional directories are specified with \fB\-I\fR options after -the \fB\-I-\fR, these directories are searched for all \fB#include\fR +the \fB\-I\-\fR, these directories are searched for all \fB#include\fR directives. (Ordinarily \fIall\fR \fB\-I\fR directories are used this way.) .Sp -In addition, the \fB\-I-\fR option inhibits the use of the current +In addition, the \fB\-I\-\fR option inhibits the use of the current directory (where the current input file came from) as the first search directory for \fB#include "\fR\fIfile\fR\fB"\fR. There is no way to -override this effect of \fB\-I-\fR. With \fB\-I.\fR you can specify +override this effect of \fB\-I\-\fR. With \fB\-I.\fR you can specify searching the directory which was current when the compiler was invoked. That is not exactly the same as what the preprocessor does by default, but it is often satisfactory. .Sp -\&\fB\-I-\fR does not inhibit the use of the standard system directories -for header files. Thus, \fB\-I-\fR and \fB\-nostdinc\fR are +\&\fB\-I\-\fR does not inhibit the use of the standard system directories +for header files. Thus, \fB\-I\-\fR and \fB\-nostdinc\fR are independent. -.Ip "\fB\-L\fR\fIdir\fR" 4 +.IP "\fB\-L\fR\fIdir\fR" 4 .IX Item "-Ldir" Add directory \fIdir\fR to the list of directories to be searched for \fB\-l\fR. -.Ip "\fB\-B\fR\fIprefix\fR" 4 +.IP "\fB\-B\fR\fIprefix\fR" 4 .IX Item "-Bprefix" This option specifies where to find the executables, libraries, include files, and data files of the compiler itself. @@ -4407,7 +5401,7 @@ without \fImachine\fR\fB/\fR\fIversion\fR\fB/\fR. For each subprogram to be run, the compiler driver first tries the \&\fB\-B\fR prefix, if any. If that name is not found, or if \fB\-B\fR was not specified, the driver tries two standard prefixes, which are -\&\fI/usr/lib/gcc/\fR and \fI/usr/local/lib/gcc-lib/\fR. If neither of +\&\fI/usr/lib/gcc/\fR and \fI/usr/local/lib/gcc/\fR. If neither of those results in a file name that is found, the unmodified program name is searched for using the directories specified in your \&\fB\s-1PATH\s0\fR environment variable. @@ -4435,7 +5429,7 @@ As a special kludge, if the path provided by \fB\-B\fR is \&\fI[dir/]stage\fIN\fI/\fR, where \fIN\fR is a number in the range 0 to 9, then it will be replaced by \fI[dir/]include\fR. This is to help with boot-strapping the compiler. -.Ip "\fB\-specs=\fR\fIfile\fR" 4 +.IP "\fB\-specs=\fR\fIfile\fR" 4 .IX Item "-specs=file" Process \fIfile\fR after the compiler reads in the standard \fIspecs\fR file, in order to override the defaults that the \fIgcc\fR driver @@ -4445,80 +5439,29 @@ program uses when determining what switches to pass to \fIcc1\fR, are processed in order, from left to right. .Sh "Specifying Target Machine and Compiler Version" .IX Subsection "Specifying Target Machine and Compiler Version" -By default, \s-1GCC\s0 compiles code for the same type of machine that you -are using. However, it can also be installed as a cross-compiler, to -compile for some other type of machine. In fact, several different -configurations of \s-1GCC\s0, for different target machines, can be -installed side by side. Then you specify which one to use with the -\&\fB\-b\fR option. -.PP -In addition, older and newer versions of \s-1GCC\s0 can be installed side -by side. One of them (probably the newest) will be the default, but -you may sometimes wish to use another. -.Ip "\fB\-b\fR \fImachine\fR" 4 +The usual way to run \s-1GCC\s0 is to run the executable called \fIgcc\fR, or +\&\fI<machine>\-gcc\fR when cross\-compiling, or +\&\fI<machine>\-gcc\-<version>\fR to run a version other than the one that +was installed last. Sometimes this is inconvenient, so \s-1GCC\s0 provides +options that will switch to another cross-compiler or version. +.IP "\fB\-b\fR \fImachine\fR" 4 .IX Item "-b machine" The argument \fImachine\fR specifies the target machine for compilation. -This is useful when you have installed \s-1GCC\s0 as a cross-compiler. .Sp The value to use for \fImachine\fR is the same as was specified as the -machine type when configuring \s-1GCC\s0 as a cross-compiler. For +machine type when configuring \s-1GCC\s0 as a cross\-compiler. For example, if a cross-compiler was configured with \fBconfigure i386v\fR, meaning to compile for an 80386 running System V, then you would specify \fB\-b i386v\fR to run that cross compiler. -.Sp -When you do not specify \fB\-b\fR, it normally means to compile for -the same type of machine that you are using. -.Ip "\fB\-V\fR \fIversion\fR" 4 +.IP "\fB\-V\fR \fIversion\fR" 4 .IX Item "-V version" The argument \fIversion\fR specifies which version of \s-1GCC\s0 to run. This is useful when multiple versions are installed. For example, \&\fIversion\fR might be \fB2.0\fR, meaning to run \s-1GCC\s0 version 2.0. -.Sp -The default version, when you do not specify \fB\-V\fR, is the last -version of \s-1GCC\s0 that you installed. -.PP -The \fB\-b\fR and \fB\-V\fR options actually work by controlling part of -the file name used for the executable files and libraries used for -compilation. A given version of \s-1GCC\s0, for a given target machine, is -normally kept in the directory \fI/usr/local/lib/gcc-lib/\fImachine\fI/\fIversion\fI\fR. .PP -Thus, sites can customize the effect of \fB\-b\fR or \fB\-V\fR either by -changing the names of these directories or adding alternate names (or -symbolic links). If in directory \fI/usr/local/lib/gcc-lib/\fR the -file \fI80386\fR is a link to the file \fIi386v\fR, then \fB\-b -80386\fR becomes an alias for \fB\-b i386v\fR. -.PP -In one respect, the \fB\-b\fR or \fB\-V\fR do not completely change -to a different compiler: the top-level driver program \fBgcc\fR -that you originally invoked continues to run and invoke the other -executables (preprocessor, compiler per se, assembler and linker) -that do the real work. However, since no real work is done in the -driver program, it usually does not matter that the driver program -in use is not the one for the specified target. It is common for the -interface to the other executables to change incompatibly between -compiler versions, so unless the version specified is very close to that -of the driver (for example, \fB\-V 3.0\fR with a driver program from \s-1GCC\s0 -version 3.0.1), use of \fB\-V\fR may not work; for example, using -\&\fB\-V 2.95.2\fR will not work with a driver program from \s-1GCC\s0 3.0. -.PP -The only way that the driver program depends on the target machine is -in the parsing and handling of special machine-specific options. -However, this is controlled by a file which is found, along with the -other executables, in the directory for the specified version and -target machine. As a result, a single installed driver program adapts -to any specified target machine, and sufficiently similar compiler -versions. -.PP -The driver program executable does control one significant thing, -however: the default version and target machine. Therefore, you can -install different instances of the driver program, compiled for -different targets or versions, under different names. -.PP -For example, if the driver for version 2.0 is installed as \fBogcc\fR -and that for version 2.1 is installed as \fBgcc\fR, then the command -\&\fBgcc\fR will use version 2.1 by default, while \fBogcc\fR will use -2.0 by default. However, you can choose either version with either -command with the \fB\-V\fR option. +The \fB\-V\fR and \fB\-b\fR options work by running the +\&\fI<machine>\-gcc\-<version>\fR executable, so there's no real reason to +use them if you can just run that directly. .Sh "Hardware Models and Configurations" .IX Subsection "Hardware Models and Configurations" Earlier we discussed the standard option \fB\-b\fR which chooses among @@ -4540,17 +5483,17 @@ These options are defined by the macro \f(CW\*(C`TARGET_SWITCHES\*(C'\fR in the machine description. The default for the options is also defined by that macro, which enables you to change the defaults. .PP -.I "M680x0 Options" +\fIM680x0 Options\fR .IX Subsection "M680x0 Options" .PP These are the \fB\-m\fR options defined for the 68000 series. The default values for these options depends on which style of 68000 was selected when the compiler was configured; the defaults for the most common choices are given below. -.Ip "\fB\-m68000\fR" 4 +.IP "\fB\-m68000\fR" 4 .IX Item "-m68000" .PD 0 -.Ip "\fB\-mc68000\fR" 4 +.IP "\fB\-mc68000\fR" 4 .IX Item "-mc68000" .PD Generate output for a 68000. This is the default @@ -4558,24 +5501,24 @@ when the compiler is configured for 68000\-based systems. .Sp Use this option for microcontrollers with a 68000 or \s-1EC000\s0 core, including the 68008, 68302, 68306, 68307, 68322, 68328 and 68356. -.Ip "\fB\-m68020\fR" 4 +.IP "\fB\-m68020\fR" 4 .IX Item "-m68020" .PD 0 -.Ip "\fB\-mc68020\fR" 4 +.IP "\fB\-mc68020\fR" 4 .IX Item "-mc68020" .PD Generate output for a 68020. This is the default when the compiler is configured for 68020\-based systems. -.Ip "\fB\-m68881\fR" 4 +.IP "\fB\-m68881\fR" 4 .IX Item "-m68881" Generate output containing 68881 instructions for floating point. -This is the default for most 68020 systems unless \fB\*(--nfp\fR was +This is the default for most 68020 systems unless \fB\-\-nfp\fR was specified when the compiler was configured. -.Ip "\fB\-m68030\fR" 4 +.IP "\fB\-m68030\fR" 4 .IX Item "-m68030" Generate output for a 68030. This is the default when the compiler is configured for 68030\-based systems. -.Ip "\fB\-m68040\fR" 4 +.IP "\fB\-m68040\fR" 4 .IX Item "-m68040" Generate output for a 68040. This is the default when the compiler is configured for 68040\-based systems. @@ -4583,7 +5526,7 @@ configured for 68040\-based systems. This option inhibits the use of 68881/68882 instructions that have to be emulated by software on the 68040. Use this option if your 68040 does not have code to emulate those instructions. -.Ip "\fB\-m68060\fR" 4 +.IP "\fB\-m68060\fR" 4 .IX Item "-m68060" Generate output for a 68060. This is the default when the compiler is configured for 68060\-based systems. @@ -4591,7 +5534,7 @@ configured for 68060\-based systems. This option inhibits the use of 68020 and 68881/68882 instructions that have to be emulated by software on the 68060. Use this option if your 68060 does not have code to emulate those instructions. -.Ip "\fB\-mcpu32\fR" 4 +.IP "\fB\-mcpu32\fR" 4 .IX Item "-mcpu32" Generate output for a \s-1CPU32\s0. This is the default when the compiler is configured for CPU32\-based systems. @@ -4599,50 +5542,47 @@ when the compiler is configured for CPU32\-based systems. Use this option for microcontrollers with a \&\s-1CPU32\s0 or \s-1CPU32+\s0 core, including the 68330, 68331, 68332, 68333, 68334, 68336, 68340, 68341, 68349 and 68360. -.Ip "\fB\-m5200\fR" 4 +.IP "\fB\-m5200\fR" 4 .IX Item "-m5200" Generate output for a 520X ``coldfire'' family cpu. This is the default -when the compiler is configured for 520X-based systems. +when the compiler is configured for 520X\-based systems. .Sp Use this option for microcontroller with a 5200 core, including the \s-1MCF5202\s0, \s-1MCF5203\s0, \s-1MCF5204\s0 and \s-1MCF5202\s0. -.Ip "\fB\-m68020\-40\fR" 4 +.IP "\fB\-m68020\-40\fR" 4 .IX Item "-m68020-40" Generate output for a 68040, without using any of the new instructions. This results in code which can run relatively efficiently on either a 68020/68881 or a 68030 or a 68040. The generated code does use the 68881 instructions that are emulated on the 68040. -.Ip "\fB\-m68020\-60\fR" 4 +.IP "\fB\-m68020\-60\fR" 4 .IX Item "-m68020-60" Generate output for a 68060, without using any of the new instructions. This results in code which can run relatively efficiently on either a 68020/68881 or a 68030 or a 68040. The generated code does use the 68881 instructions that are emulated on the 68060. -.Ip "\fB\-mfpa\fR" 4 -.IX Item "-mfpa" -Generate output containing Sun \s-1FPA\s0 instructions for floating point. -.Ip "\fB\-msoft-float\fR" 4 +.IP "\fB\-msoft\-float\fR" 4 .IX Item "-msoft-float" Generate output containing library calls for floating point. \&\fBWarning:\fR the requisite libraries are not available for all m68k targets. Normally the facilities of the machine's usual C compiler are -used, but this can't be done directly in cross-compilation. You must +used, but this can't be done directly in cross\-compilation. You must make your own arrangements to provide suitable library functions for -cross-compilation. The embedded targets \fBm68k-*\-aout\fR and -\&\fBm68k-*\-coff\fR do provide software floating point support. -.Ip "\fB\-mshort\fR" 4 +cross\-compilation. The embedded targets \fBm68k\-*\-aout\fR and +\&\fBm68k\-*\-coff\fR do provide software floating point support. +.IP "\fB\-mshort\fR" 4 .IX Item "-mshort" Consider type \f(CW\*(C`int\*(C'\fR to be 16 bits wide, like \f(CW\*(C`short int\*(C'\fR. -.Ip "\fB\-mnobitfield\fR" 4 +.IP "\fB\-mnobitfield\fR" 4 .IX Item "-mnobitfield" Do not use the bit-field instructions. The \fB\-m68000\fR, \fB\-mcpu32\fR and \fB\-m5200\fR options imply \fB\-mnobitfield\fR. -.Ip "\fB\-mbitfield\fR" 4 +.IP "\fB\-mbitfield\fR" 4 .IX Item "-mbitfield" Do use the bit-field instructions. The \fB\-m68020\fR option implies \&\fB\-mbitfield\fR. This is the default if you use a configuration designed for a 68020. -.Ip "\fB\-mrtd\fR" 4 +.IP "\fB\-mrtd\fR" 4 .IX Item "-mrtd" Use a different function-calling convention, in which functions that take a fixed number of arguments return with the \f(CW\*(C`rtd\*(C'\fR @@ -4665,240 +5605,288 @@ harmlessly ignored.) .Sp The \f(CW\*(C`rtd\*(C'\fR instruction is supported by the 68010, 68020, 68030, 68040, 68060 and \s-1CPU32\s0 processors, but not by the 68000 or 5200. -.Ip "\fB\-malign-int\fR" 4 +.IP "\fB\-malign\-int\fR" 4 .IX Item "-malign-int" .PD 0 -.Ip "\fB\-mno-align-int\fR" 4 +.IP "\fB\-mno\-align\-int\fR" 4 .IX Item "-mno-align-int" .PD Control whether \s-1GCC\s0 aligns \f(CW\*(C`int\*(C'\fR, \f(CW\*(C`long\*(C'\fR, \f(CW\*(C`long long\*(C'\fR, \&\f(CW\*(C`float\*(C'\fR, \f(CW\*(C`double\*(C'\fR, and \f(CW\*(C`long double\*(C'\fR variables on a 32\-bit -boundary (\fB\-malign-int\fR) or a 16\-bit boundary (\fB\-mno-align-int\fR). +boundary (\fB\-malign\-int\fR) or a 16\-bit boundary (\fB\-mno\-align\-int\fR). Aligning variables on 32\-bit boundaries produces code that runs somewhat faster on processors with 32\-bit busses at the expense of more memory. .Sp -\&\fBWarning:\fR if you use the \fB\-malign-int\fR switch, \s-1GCC\s0 will +\&\fBWarning:\fR if you use the \fB\-malign\-int\fR switch, \s-1GCC\s0 will align structures containing the above types differently than most published application binary interface specifications for the m68k. -.Ip "\fB\-mpcrel\fR" 4 +.IP "\fB\-mpcrel\fR" 4 .IX Item "-mpcrel" Use the pc-relative addressing mode of the 68000 directly, instead of using a global offset table. At present, this option implies \fB\-fpic\fR, allowing at most a 16\-bit offset for pc-relative addressing. \fB\-fPIC\fR is not presently supported with \fB\-mpcrel\fR, though this could be supported for 68020 and higher processors. -.Ip "\fB\-mno-strict-align\fR" 4 +.IP "\fB\-mno\-strict\-align\fR" 4 .IX Item "-mno-strict-align" .PD 0 -.Ip "\fB\-mstrict-align\fR" 4 +.IP "\fB\-mstrict\-align\fR" 4 .IX Item "-mstrict-align" .PD Do not (do) assume that unaligned memory references will be handled by the system. +.IP "\fB\-msep\-data\fR" 4 +.IX Item "-msep-data" +Generate code that allows the data segment to be located in a different +area of memory from the text segment. This allows for execute in place in +an environment without virtual memory management. This option implies \-fPIC. +.IP "\fB\-mno\-sep\-data\fR" 4 +.IX Item "-mno-sep-data" +Generate code that assumes that the data segment follows the text segment. +This is the default. +.IP "\fB\-mid\-shared\-library\fR" 4 +.IX Item "-mid-shared-library" +Generate code that supports shared libraries via the library \s-1ID\s0 method. +This allows for execute in place and shared libraries in an environment +without virtual memory management. This option implies \-fPIC. +.IP "\fB\-mno\-id\-shared\-library\fR" 4 +.IX Item "-mno-id-shared-library" +Generate code that doesn't assume \s-1ID\s0 based shared libraries are being used. +This is the default. +.IP "\fB\-mshared\-library\-id=n\fR" 4 +.IX Item "-mshared-library-id=n" +Specified the identification number of the \s-1ID\s0 based shared library being +compiled. Specifying a value of 0 will generate more compact code, specifying +other values will force the allocation of that number to the current +library but is no more space or time efficient than omitting this option. .PP -.I "M68hc1x Options" +\fIM68hc1x Options\fR .IX Subsection "M68hc1x Options" .PP These are the \fB\-m\fR options defined for the 68hc11 and 68hc12 microcontrollers. The default values for these options depends on which style of microcontroller was selected when the compiler was configured; the defaults for the most common choices are given below. -.Ip "\fB\-m6811\fR" 4 +.IP "\fB\-m6811\fR" 4 .IX Item "-m6811" .PD 0 -.Ip "\fB\-m68hc11\fR" 4 +.IP "\fB\-m68hc11\fR" 4 .IX Item "-m68hc11" .PD Generate output for a 68HC11. This is the default when the compiler is configured for 68HC11\-based systems. -.Ip "\fB\-m6812\fR" 4 +.IP "\fB\-m6812\fR" 4 .IX Item "-m6812" .PD 0 -.Ip "\fB\-m68hc12\fR" 4 +.IP "\fB\-m68hc12\fR" 4 .IX Item "-m68hc12" .PD Generate output for a 68HC12. This is the default when the compiler is configured for 68HC12\-based systems. -.Ip "\fB\-mauto-incdec\fR" 4 +.IP "\fB\-m68S12\fR" 4 +.IX Item "-m68S12" +.PD 0 +.IP "\fB\-m68hcs12\fR" 4 +.IX Item "-m68hcs12" +.PD +Generate output for a 68HCS12. +.IP "\fB\-mauto\-incdec\fR" 4 .IX Item "-mauto-incdec" Enable the use of 68HC12 pre and post auto-increment and auto-decrement addressing modes. -.Ip "\fB\-mshort\fR" 4 +.IP "\fB\-minmax\fR" 4 +.IX Item "-minmax" +.PD 0 +.IP "\fB\-nominmax\fR" 4 +.IX Item "-nominmax" +.PD +Enable the use of 68HC12 min and max instructions. +.IP "\fB\-mlong\-calls\fR" 4 +.IX Item "-mlong-calls" +.PD 0 +.IP "\fB\-mno\-long\-calls\fR" 4 +.IX Item "-mno-long-calls" +.PD +Treat all calls as being far away (near). If calls are assumed to be +far away, the compiler will use the \f(CW\*(C`call\*(C'\fR instruction to +call a function and the \f(CW\*(C`rtc\*(C'\fR instruction for returning. +.IP "\fB\-mshort\fR" 4 .IX Item "-mshort" Consider type \f(CW\*(C`int\*(C'\fR to be 16 bits wide, like \f(CW\*(C`short int\*(C'\fR. -.Ip "\fB\-msoft-reg-count=\fR\fIcount\fR" 4 +.IP "\fB\-msoft\-reg\-count=\fR\fIcount\fR" 4 .IX Item "-msoft-reg-count=count" Specify the number of pseudo-soft registers which are used for the code generation. The maximum number is 32. Using more pseudo-soft register may or may not result in better code depending on the program. The default is 4 for 68HC11 and 2 for 68HC12. .PP -.I "\s-1VAX\s0 Options" +\fI\s-1VAX\s0 Options\fR .IX Subsection "VAX Options" .PP These \fB\-m\fR options are defined for the \s-1VAX:\s0 -.Ip "\fB\-munix\fR" 4 +.IP "\fB\-munix\fR" 4 .IX Item "-munix" Do not output certain jump instructions (\f(CW\*(C`aobleq\*(C'\fR and so on) that the Unix assembler for the \s-1VAX\s0 cannot handle across long ranges. -.Ip "\fB\-mgnu\fR" 4 +.IP "\fB\-mgnu\fR" 4 .IX Item "-mgnu" Do output those jump instructions, on the assumption that you will assemble with the \s-1GNU\s0 assembler. -.Ip "\fB\-mg\fR" 4 +.IP "\fB\-mg\fR" 4 .IX Item "-mg" -Output code for g-format floating point numbers instead of d-format. +Output code for g\-format floating point numbers instead of d\-format. .PP -.I "\s-1SPARC\s0 Options" +\fI\s-1SPARC\s0 Options\fR .IX Subsection "SPARC Options" .PP -These \fB\-m\fR switches are supported on the \s-1SPARC:\s0 -.Ip "\fB\-mno-app-regs\fR" 4 +These \fB\-m\fR options are supported on the \s-1SPARC:\s0 +.IP "\fB\-mno\-app\-regs\fR" 4 .IX Item "-mno-app-regs" .PD 0 -.Ip "\fB\-mapp-regs\fR" 4 +.IP "\fB\-mapp\-regs\fR" 4 .IX Item "-mapp-regs" .PD -Specify \fB\-mapp-regs\fR to generate output using the global registers +Specify \fB\-mapp\-regs\fR to generate output using the global registers 2 through 4, which the \s-1SPARC\s0 \s-1SVR4\s0 \s-1ABI\s0 reserves for applications. This -is the default. +is the default, except on Solaris. .Sp To be fully \s-1SVR4\s0 \s-1ABI\s0 compliant at the cost of some performance loss, -specify \fB\-mno-app-regs\fR. You should compile libraries and system +specify \fB\-mno\-app\-regs\fR. You should compile libraries and system software with this option. -.Ip "\fB\-mfpu\fR" 4 +.IP "\fB\-mfpu\fR" 4 .IX Item "-mfpu" .PD 0 -.Ip "\fB\-mhard-float\fR" 4 +.IP "\fB\-mhard\-float\fR" 4 .IX Item "-mhard-float" .PD Generate output containing floating point instructions. This is the default. -.Ip "\fB\-mno-fpu\fR" 4 +.IP "\fB\-mno\-fpu\fR" 4 .IX Item "-mno-fpu" .PD 0 -.Ip "\fB\-msoft-float\fR" 4 +.IP "\fB\-msoft\-float\fR" 4 .IX Item "-msoft-float" .PD Generate output containing library calls for floating point. \&\fBWarning:\fR the requisite libraries are not available for all \s-1SPARC\s0 targets. Normally the facilities of the machine's usual C compiler are -used, but this cannot be done directly in cross-compilation. You must make +used, but this cannot be done directly in cross\-compilation. You must make your own arrangements to provide suitable library functions for -cross-compilation. The embedded targets \fBsparc-*\-aout\fR and -\&\fBsparclite-*\-*\fR do provide software floating point support. +cross\-compilation. The embedded targets \fBsparc\-*\-aout\fR and +\&\fBsparclite\-*\-*\fR do provide software floating point support. .Sp -\&\fB\-msoft-float\fR changes the calling convention in the output file; +\&\fB\-msoft\-float\fR changes the calling convention in the output file; therefore, it is only useful if you compile \fIall\fR of a program with this option. In particular, you need to compile \fIlibgcc.a\fR, the -library that comes with \s-1GCC\s0, with \fB\-msoft-float\fR in order for +library that comes with \s-1GCC\s0, with \fB\-msoft\-float\fR in order for this to work. -.Ip "\fB\-mhard-quad-float\fR" 4 +.IP "\fB\-mhard\-quad\-float\fR" 4 .IX Item "-mhard-quad-float" Generate output containing quad-word (long double) floating point instructions. -.Ip "\fB\-msoft-quad-float\fR" 4 +.IP "\fB\-msoft\-quad\-float\fR" 4 .IX Item "-msoft-quad-float" Generate output containing library calls for quad-word (long double) floating point instructions. The functions called are those specified in the \s-1SPARC\s0 \s-1ABI\s0. This is the default. .Sp -As of this writing, there are no sparc implementations that have hardware +As of this writing, there are no \s-1SPARC\s0 implementations that have hardware support for the quad-word floating point instructions. They all invoke a trap handler for one of these instructions, and then the trap handler emulates the effect of the instruction. Because of the trap handler overhead, this is much slower than calling the \s-1ABI\s0 library routines. Thus the -\&\fB\-msoft-quad-float\fR option is the default. -.Ip "\fB\-mno-flat\fR" 4 +\&\fB\-msoft\-quad\-float\fR option is the default. +.IP "\fB\-mno\-flat\fR" 4 .IX Item "-mno-flat" .PD 0 -.Ip "\fB\-mflat\fR" 4 +.IP "\fB\-mflat\fR" 4 .IX Item "-mflat" .PD With \fB\-mflat\fR, the compiler does not generate save/restore instructions and will use a ``flat'' or single register window calling convention. This model uses \f(CW%i7\fR as the frame pointer and is compatible with the normal register window model. Code from either may be intermixed. -The local registers and the input registers (0\*(--5) are still treated as +The local registers and the input registers (0\-\-5) are still treated as ``call saved'' registers and will be saved on the stack as necessary. .Sp -With \fB\-mno-flat\fR (the default), the compiler emits save/restore +With \fB\-mno\-flat\fR (the default), the compiler emits save/restore instructions (except for leaf functions) and is the normal mode of operation. -.Ip "\fB\-mno-unaligned-doubles\fR" 4 +.Sp +These options are deprecated and will be deleted in a future \s-1GCC\s0 release. +.IP "\fB\-mno\-unaligned\-doubles\fR" 4 .IX Item "-mno-unaligned-doubles" .PD 0 -.Ip "\fB\-munaligned-doubles\fR" 4 +.IP "\fB\-munaligned\-doubles\fR" 4 .IX Item "-munaligned-doubles" .PD Assume that doubles have 8 byte alignment. This is the default. .Sp -With \fB\-munaligned-doubles\fR, \s-1GCC\s0 assumes that doubles have 8 byte +With \fB\-munaligned\-doubles\fR, \s-1GCC\s0 assumes that doubles have 8 byte alignment only if they are contained in another type, or if they have an absolute address. Otherwise, it assumes they have 4 byte alignment. Specifying this option avoids some rare compatibility problems with code generated by other compilers. It is not the default because it results in a performance loss, especially for floating point code. -.Ip "\fB\-mno-faster-structs\fR" 4 +.IP "\fB\-mno\-faster\-structs\fR" 4 .IX Item "-mno-faster-structs" .PD 0 -.Ip "\fB\-mfaster-structs\fR" 4 +.IP "\fB\-mfaster\-structs\fR" 4 .IX Item "-mfaster-structs" .PD -With \fB\-mfaster-structs\fR, the compiler assumes that structures +With \fB\-mfaster\-structs\fR, the compiler assumes that structures should have 8 byte alignment. This enables the use of pairs of \&\f(CW\*(C`ldd\*(C'\fR and \f(CW\*(C`std\*(C'\fR instructions for copies in structure assignment, in place of twice as many \f(CW\*(C`ld\*(C'\fR and \f(CW\*(C`st\*(C'\fR pairs. -However, the use of this changed alignment directly violates the Sparc +However, the use of this changed alignment directly violates the \s-1SPARC\s0 \&\s-1ABI\s0. Thus, it's intended only for use on targets where the developer acknowledges that their resulting code will not be directly in line with the rules of the \s-1ABI\s0. -.Ip "\fB\-mv8\fR" 4 +.IP "\fB\-mimpure\-text\fR" 4 +.IX Item "-mimpure-text" +\&\fB\-mimpure\-text\fR, used in addition to \fB\-shared\fR, tells +the compiler to not pass \fB\-z text\fR to the linker when linking a +shared object. Using this option, you can link position-dependent +code into a shared object. +.Sp +\&\fB\-mimpure\-text\fR suppresses the ``relocations remain against +allocatable but non-writable sections'' linker error message. +However, the necessary relocations will trigger copy\-on\-write, and the +shared object is not actually shared across processes. Instead of +using \fB\-mimpure\-text\fR, you should compile all source code with +\&\fB\-fpic\fR or \fB\-fPIC\fR. +.Sp +This option is only available on SunOS and Solaris. +.IP "\fB\-mv8\fR" 4 .IX Item "-mv8" .PD 0 -.Ip "\fB\-msparclite\fR" 4 +.IP "\fB\-msparclite\fR" 4 .IX Item "-msparclite" .PD These two options select variations on the \s-1SPARC\s0 architecture. -.Sp -By default (unless specifically configured for the Fujitsu SPARClite), -\&\s-1GCC\s0 generates code for the v7 variant of the \s-1SPARC\s0 architecture. -.Sp -\&\fB\-mv8\fR will give you \s-1SPARC\s0 v8 code. The only difference from v7 -code is that the compiler emits the integer multiply and integer -divide instructions which exist in \s-1SPARC\s0 v8 but not in \s-1SPARC\s0 v7. -.Sp -\&\fB\-msparclite\fR will give you SPARClite code. This adds the integer -multiply, integer divide step and scan (\f(CW\*(C`ffs\*(C'\fR) instructions which -exist in SPARClite but not in \s-1SPARC\s0 v7. -.Sp These options are deprecated and will be deleted in a future \s-1GCC\s0 release. They have been replaced with \fB\-mcpu=xxx\fR. -.Ip "\fB\-mcypress\fR" 4 +.IP "\fB\-mcypress\fR" 4 .IX Item "-mcypress" .PD 0 -.Ip "\fB\-msupersparc\fR" 4 +.IP "\fB\-msupersparc\fR" 4 .IX Item "-msupersparc" +.IP "\fB\-mf930\fR" 4 +.IX Item "-mf930" +.IP "\fB\-mf934\fR" 4 +.IX Item "-mf934" .PD -These two options select the processor for which the code is optimized. -.Sp -With \fB\-mcypress\fR (the default), the compiler optimizes code for the -Cypress \s-1CY7C602\s0 chip, as used in the SparcStation/SparcServer 3xx series. -This is also appropriate for the older SparcStation 1, 2, \s-1IPX\s0 etc. -.Sp -With \fB\-msupersparc\fR the compiler optimizes code for the SuperSparc cpu, as -used in the SparcStation 10, 1000 and 2000 series. This flag also enables use -of the full \s-1SPARC\s0 v8 instruction set. -.Sp +These four options select the processor for which the code is optimized. These options are deprecated and will be deleted in a future \s-1GCC\s0 release. They have been replaced with \fB\-mcpu=xxx\fR. -.Ip "\fB\-mcpu=\fR\fIcpu_type\fR" 4 +.IP "\fB\-mcpu=\fR\fIcpu_type\fR" 4 .IX Item "-mcpu=cpu_type" Set the instruction set, register set, and instruction scheduling parameters for machine type \fIcpu_type\fR. Supported values for \fIcpu_type\fR are \&\fBv7\fR, \fBcypress\fR, \fBv8\fR, \fBsupersparc\fR, \fBsparclite\fR, -\&\fBhypersparc\fR, \fBsparclite86x\fR, \fBf930\fR, \fBf934\fR, -\&\fBsparclet\fR, \fBtsc701\fR, \fBv9\fR, and \fBultrasparc\fR. +\&\fBf930\fR, \fBf934\fR, \fBhypersparc\fR, \fBsparclite86x\fR, +\&\fBsparclet\fR, \fBtsc701\fR, \fBv9\fR, \fBultrasparc\fR, and +\&\fBultrasparc3\fR. .Sp Default instruction scheduling parameters are used for values that select an architecture and not an implementation. These are \fBv7\fR, \fBv8\fR, @@ -4912,9 +5900,44 @@ implementations. \& v8: supersparc, hypersparc \& sparclite: f930, f934, sparclite86x \& sparclet: tsc701 -\& v9: ultrasparc +\& v9: ultrasparc, ultrasparc3 .Ve -.Ip "\fB\-mtune=\fR\fIcpu_type\fR" 4 +.Sp +By default (unless configured otherwise), \s-1GCC\s0 generates code for the V7 +variant of the \s-1SPARC\s0 architecture. With \fB\-mcpu=cypress\fR, the compiler +additionally optimizes it for the Cypress \s-1CY7C602\s0 chip, as used in the +SPARCStation/SPARCServer 3xx series. This is also appropriate for the older +SPARCStation 1, 2, \s-1IPX\s0 etc. +.Sp +With \fB\-mcpu=v8\fR, \s-1GCC\s0 generates code for the V8 variant of the \s-1SPARC\s0 +architecture. The only difference from V7 code is that the compiler emits +the integer multiply and integer divide instructions which exist in \s-1SPARC\-V8\s0 +but not in \s-1SPARC\-V7\s0. With \fB\-mcpu=supersparc\fR, the compiler additionally +optimizes it for the SuperSPARC chip, as used in the SPARCStation 10, 1000 and +2000 series. +.Sp +With \fB\-mcpu=sparclite\fR, \s-1GCC\s0 generates code for the SPARClite variant of +the \s-1SPARC\s0 architecture. This adds the integer multiply, integer divide step +and scan (\f(CW\*(C`ffs\*(C'\fR) instructions which exist in SPARClite but not in \s-1SPARC\-V7\s0. +With \fB\-mcpu=f930\fR, the compiler additionally optimizes it for the +Fujitsu \s-1MB86930\s0 chip, which is the original SPARClite, with no \s-1FPU\s0. With +\&\fB\-mcpu=f934\fR, the compiler additionally optimizes it for the Fujitsu +\&\s-1MB86934\s0 chip, which is the more recent SPARClite with \s-1FPU\s0. +.Sp +With \fB\-mcpu=sparclet\fR, \s-1GCC\s0 generates code for the SPARClet variant of +the \s-1SPARC\s0 architecture. This adds the integer multiply, multiply/accumulate, +integer divide step and scan (\f(CW\*(C`ffs\*(C'\fR) instructions which exist in SPARClet +but not in \s-1SPARC\-V7\s0. With \fB\-mcpu=tsc701\fR, the compiler additionally +optimizes it for the \s-1TEMIC\s0 SPARClet chip. +.Sp +With \fB\-mcpu=v9\fR, \s-1GCC\s0 generates code for the V9 variant of the \s-1SPARC\s0 +architecture. This adds 64\-bit integer and floating-point move instructions, +3 additional floating-point condition code registers and conditional move +instructions. With \fB\-mcpu=ultrasparc\fR, the compiler additionally +optimizes it for the Sun UltraSPARC I/II chips. With +\&\fB\-mcpu=ultrasparc3\fR, the compiler additionally optimizes it for the +Sun UltraSPARC \s-1III\s0 chip. +.IP "\fB\-mtune=\fR\fIcpu_type\fR" 4 .IX Item "-mtune=cpu_type" Set the instruction scheduling parameters for machine type \&\fIcpu_type\fR, but do not set the instruction set or register set that the @@ -4924,270 +5947,131 @@ The same values for \fB\-mcpu=\fR\fIcpu_type\fR can be used for \&\fB\-mtune=\fR\fIcpu_type\fR, but the only useful values are those that select a particular cpu implementation. Those are \fBcypress\fR, \&\fBsupersparc\fR, \fBhypersparc\fR, \fBf930\fR, \fBf934\fR, -\&\fBsparclite86x\fR, \fBtsc701\fR, and \fBultrasparc\fR. -.PP -These \fB\-m\fR switches are supported in addition to the above -on the \s-1SPARCLET\s0 processor. -.Ip "\fB\-mlittle-endian\fR" 4 -.IX Item "-mlittle-endian" -Generate code for a processor running in little-endian mode. -.Ip "\fB\-mlive-g0\fR" 4 -.IX Item "-mlive-g0" -Treat register \f(CW\*(C`%g0\*(C'\fR as a normal register. -\&\s-1GCC\s0 will continue to clobber it as necessary but will not assume -it always reads as 0. -.Ip "\fB\-mbroken-saverestore\fR" 4 -.IX Item "-mbroken-saverestore" -Generate code that does not use non-trivial forms of the \f(CW\*(C`save\*(C'\fR and -\&\f(CW\*(C`restore\*(C'\fR instructions. Early versions of the \s-1SPARCLET\s0 processor do -not correctly handle \f(CW\*(C`save\*(C'\fR and \f(CW\*(C`restore\*(C'\fR instructions used with -arguments. They correctly handle them used without arguments. A \f(CW\*(C`save\*(C'\fR -instruction used without arguments increments the current window pointer -but does not allocate a new stack frame. It is assumed that the window -overflow trap handler will properly handle this case as will interrupt -handlers. +\&\fBsparclite86x\fR, \fBtsc701\fR, \fBultrasparc\fR, and +\&\fBultrasparc3\fR. +.IP "\fB\-mv8plus\fR" 4 +.IX Item "-mv8plus" +.PD 0 +.IP "\fB\-mno\-v8plus\fR" 4 +.IX Item "-mno-v8plus" +.PD +With \fB\-mv8plus\fR, \s-1GCC\s0 generates code for the \s-1SPARC\-V8+\s0 \s-1ABI\s0. The +difference from the V8 \s-1ABI\s0 is that the global and out registers are +considered 64\-bit wide. This is enabled by default on Solaris in 32\-bit +mode for all \s-1SPARC\-V9\s0 processors. +.IP "\fB\-mvis\fR" 4 +.IX Item "-mvis" +.PD 0 +.IP "\fB\-mno\-vis\fR" 4 +.IX Item "-mno-vis" +.PD +With \fB\-mvis\fR, \s-1GCC\s0 generates code that takes advantage of the UltraSPARC +Visual Instruction Set extensions. The default is \fB\-mno\-vis\fR. .PP -These \fB\-m\fR switches are supported in addition to the above -on \s-1SPARC\s0 V9 processors in 64\-bit environments. -.Ip "\fB\-mlittle-endian\fR" 4 +These \fB\-m\fR options are supported in addition to the above +on \s-1SPARC\-V9\s0 processors in 64\-bit environments: +.IP "\fB\-mlittle\-endian\fR" 4 .IX Item "-mlittle-endian" -Generate code for a processor running in little-endian mode. -.Ip "\fB\-m32\fR" 4 +Generate code for a processor running in little-endian mode. It is only +available for a few configurations and most notably not on Solaris and Linux. +.IP "\fB\-m32\fR" 4 .IX Item "-m32" .PD 0 -.Ip "\fB\-m64\fR" 4 +.IP "\fB\-m64\fR" 4 .IX Item "-m64" .PD Generate code for a 32\-bit or 64\-bit environment. The 32\-bit environment sets int, long and pointer to 32 bits. The 64\-bit environment sets int to 32 bits and long and pointer to 64 bits. -.Ip "\fB\-mcmodel=medlow\fR" 4 +.IP "\fB\-mcmodel=medlow\fR" 4 .IX Item "-mcmodel=medlow" -Generate code for the Medium/Low code model: the program must be linked -in the low 32 bits of the address space. Pointers are 64 bits. -Programs can be statically or dynamically linked. -.Ip "\fB\-mcmodel=medmid\fR" 4 +Generate code for the Medium/Low code model: 64\-bit addresses, programs +must be linked in the low 32 bits of memory. Programs can be statically +or dynamically linked. +.IP "\fB\-mcmodel=medmid\fR" 4 .IX Item "-mcmodel=medmid" -Generate code for the Medium/Middle code model: the program must be linked -in the low 44 bits of the address space, the text segment must be less than -2G bytes, and data segment must be within 2G of the text segment. -Pointers are 64 bits. -.Ip "\fB\-mcmodel=medany\fR" 4 +Generate code for the Medium/Middle code model: 64\-bit addresses, programs +must be linked in the low 44 bits of memory, the text and data segments must +be less than 2GB in size and the data segment must be located within 2GB of +the text segment. +.IP "\fB\-mcmodel=medany\fR" 4 .IX Item "-mcmodel=medany" -Generate code for the Medium/Anywhere code model: the program may be linked -anywhere in the address space, the text segment must be less than -2G bytes, and data segment must be within 2G of the text segment. -Pointers are 64 bits. -.Ip "\fB\-mcmodel=embmedany\fR" 4 +Generate code for the Medium/Anywhere code model: 64\-bit addresses, programs +may be linked anywhere in memory, the text and data segments must be less +than 2GB in size and the data segment must be located within 2GB of the +text segment. +.IP "\fB\-mcmodel=embmedany\fR" 4 .IX Item "-mcmodel=embmedany" Generate code for the Medium/Anywhere code model for embedded systems: -assume a 32\-bit text and a 32\-bit data segment, both starting anywhere -(determined at link time). Register \f(CW%g4\fR points to the base of the -data segment. Pointers are still 64 bits. -Programs are statically linked, \s-1PIC\s0 is not supported. -.Ip "\fB\-mstack-bias\fR" 4 +64\-bit addresses, the text and data segments must be less than 2GB in +size, both starting anywhere in memory (determined at link time). The +global register \f(CW%g4\fR points to the base of the data segment. Programs +are statically linked and \s-1PIC\s0 is not supported. +.IP "\fB\-mstack\-bias\fR" 4 .IX Item "-mstack-bias" .PD 0 -.Ip "\fB\-mno-stack-bias\fR" 4 +.IP "\fB\-mno\-stack\-bias\fR" 4 .IX Item "-mno-stack-bias" .PD -With \fB\-mstack-bias\fR, \s-1GCC\s0 assumes that the stack pointer, and +With \fB\-mstack\-bias\fR, \s-1GCC\s0 assumes that the stack pointer, and frame pointer if present, are offset by \-2047 which must be added back -when making stack frame references. +when making stack frame references. This is the default in 64\-bit mode. Otherwise, assume no such offset is present. .PP -.I "Convex Options" -.IX Subsection "Convex Options" -.PP -These \fB\-m\fR options are defined for Convex: -.Ip "\fB\-mc1\fR" 4 -.IX Item "-mc1" -Generate output for C1. The code will run on any Convex machine. -The preprocessor symbol \f(CW\*(C`_\|_convex_\|_c1_\|_\*(C'\fR is defined. -.Ip "\fB\-mc2\fR" 4 -.IX Item "-mc2" -Generate output for C2. Uses instructions not available on C1. -Scheduling and other optimizations are chosen for max performance on C2. -The preprocessor symbol \f(CW\*(C`_\|_convex_c2_\|_\*(C'\fR is defined. -.Ip "\fB\-mc32\fR" 4 -.IX Item "-mc32" -Generate output for C32xx. Uses instructions not available on C1. -Scheduling and other optimizations are chosen for max performance on C32. -The preprocessor symbol \f(CW\*(C`_\|_convex_c32_\|_\*(C'\fR is defined. -.Ip "\fB\-mc34\fR" 4 -.IX Item "-mc34" -Generate output for C34xx. Uses instructions not available on C1. -Scheduling and other optimizations are chosen for max performance on C34. -The preprocessor symbol \f(CW\*(C`_\|_convex_c34_\|_\*(C'\fR is defined. -.Ip "\fB\-mc38\fR" 4 -.IX Item "-mc38" -Generate output for C38xx. Uses instructions not available on C1. -Scheduling and other optimizations are chosen for max performance on C38. -The preprocessor symbol \f(CW\*(C`_\|_convex_c38_\|_\*(C'\fR is defined. -.Ip "\fB\-margcount\fR" 4 -.IX Item "-margcount" -Generate code which puts an argument count in the word preceding each -argument list. This is compatible with regular \s-1CC\s0, and a few programs -may need the argument count word. \s-1GDB\s0 and other source-level debuggers -do not need it; this info is in the symbol table. -.Ip "\fB\-mnoargcount\fR" 4 -.IX Item "-mnoargcount" -Omit the argument count word. This is the default. -.Ip "\fB\-mvolatile-cache\fR" 4 -.IX Item "-mvolatile-cache" -Allow volatile references to be cached. This is the default. -.Ip "\fB\-mvolatile-nocache\fR" 4 -.IX Item "-mvolatile-nocache" -Volatile references bypass the data cache, going all the way to memory. -This is only needed for multi-processor code that does not use standard -synchronization instructions. Making non-volatile references to volatile -locations will not necessarily work. -.Ip "\fB\-mlong32\fR" 4 -.IX Item "-mlong32" -Type long is 32 bits, the same as type int. This is the default. -.Ip "\fB\-mlong64\fR" 4 -.IX Item "-mlong64" -Type long is 64 bits, the same as type long long. This option is useless, -because no library support exists for it. -.PP -.I "\s-1AMD29K\s0 Options" -.IX Subsection "AMD29K Options" -.PP -These \fB\-m\fR options are defined for the \s-1AMD\s0 Am29000: -.Ip "\fB\-mdw\fR" 4 -.IX Item "-mdw" -Generate code that assumes the \f(CW\*(C`DW\*(C'\fR bit is set, i.e., that byte and -halfword operations are directly supported by the hardware. This is the -default. -.Ip "\fB\-mndw\fR" 4 -.IX Item "-mndw" -Generate code that assumes the \f(CW\*(C`DW\*(C'\fR bit is not set. -.Ip "\fB\-mbw\fR" 4 -.IX Item "-mbw" -Generate code that assumes the system supports byte and halfword write -operations. This is the default. -.Ip "\fB\-mnbw\fR" 4 -.IX Item "-mnbw" -Generate code that assumes the systems does not support byte and -halfword write operations. \fB\-mnbw\fR implies \fB\-mndw\fR. -.Ip "\fB\-msmall\fR" 4 -.IX Item "-msmall" -Use a small memory model that assumes that all function addresses are -either within a single 256 \s-1KB\s0 segment or at an absolute address of less -than 256k. This allows the \f(CW\*(C`call\*(C'\fR instruction to be used instead -of a \f(CW\*(C`const\*(C'\fR, \f(CW\*(C`consth\*(C'\fR, \f(CW\*(C`calli\*(C'\fR sequence. -.Ip "\fB\-mnormal\fR" 4 -.IX Item "-mnormal" -Use the normal memory model: Generate \f(CW\*(C`call\*(C'\fR instructions only when -calling functions in the same file and \f(CW\*(C`calli\*(C'\fR instructions -otherwise. This works if each file occupies less than 256 \s-1KB\s0 but allows -the entire executable to be larger than 256 \s-1KB\s0. This is the default. -.Ip "\fB\-mlarge\fR" 4 -.IX Item "-mlarge" -Always use \f(CW\*(C`calli\*(C'\fR instructions. Specify this option if you expect -a single file to compile into more than 256 \s-1KB\s0 of code. -.Ip "\fB\-m29050\fR" 4 -.IX Item "-m29050" -Generate code for the Am29050. -.Ip "\fB\-m29000\fR" 4 -.IX Item "-m29000" -Generate code for the Am29000. This is the default. -.Ip "\fB\-mkernel-registers\fR" 4 -.IX Item "-mkernel-registers" -Generate references to registers \f(CW\*(C`gr64\-gr95\*(C'\fR instead of to -registers \f(CW\*(C`gr96\-gr127\*(C'\fR. This option can be used when compiling -kernel code that wants a set of global registers disjoint from that used -by user-mode code. -.Sp -Note that when this option is used, register names in \fB\-f\fR flags -must use the normal, user-mode, names. -.Ip "\fB\-muser-registers\fR" 4 -.IX Item "-muser-registers" -Use the normal set of global registers, \f(CW\*(C`gr96\-gr127\*(C'\fR. This is the -default. -.Ip "\fB\-mstack-check\fR" 4 -.IX Item "-mstack-check" -.PD 0 -.Ip "\fB\-mno-stack-check\fR" 4 -.IX Item "-mno-stack-check" -.PD -Insert (or do not insert) a call to \f(CW\*(C`_\|_msp_check\*(C'\fR after each stack -adjustment. This is often used for kernel code. -.Ip "\fB\-mstorem-bug\fR" 4 -.IX Item "-mstorem-bug" -.PD 0 -.Ip "\fB\-mno-storem-bug\fR" 4 -.IX Item "-mno-storem-bug" -.PD -\&\fB\-mstorem-bug\fR handles 29k processors which cannot handle the -separation of a mtsrim insn and a storem instruction (most 29000 chips -to date, but not the 29050). -.Ip "\fB\-mno-reuse-arg-regs\fR" 4 -.IX Item "-mno-reuse-arg-regs" -.PD 0 -.Ip "\fB\-mreuse-arg-regs\fR" 4 -.IX Item "-mreuse-arg-regs" -.PD -\&\fB\-mno-reuse-arg-regs\fR tells the compiler to only use incoming argument -registers for copying out arguments. This helps detect calling a function -with fewer arguments than it was declared with. -.Ip "\fB\-mno-impure-text\fR" 4 -.IX Item "-mno-impure-text" -.PD 0 -.Ip "\fB\-mimpure-text\fR" 4 -.IX Item "-mimpure-text" -.PD -\&\fB\-mimpure-text\fR, used in addition to \fB\-shared\fR, tells the compiler to -not pass \fB\-assert pure-text\fR to the linker when linking a shared object. -.Ip "\fB\-msoft-float\fR" 4 -.IX Item "-msoft-float" -Generate output containing library calls for floating point. -\&\fBWarning:\fR the requisite libraries are not part of \s-1GCC\s0. -Normally the facilities of the machine's usual C compiler are used, but -this can't be done directly in cross-compilation. You must make your -own arrangements to provide suitable library functions for -cross-compilation. -.Ip "\fB\-mno-multm\fR" 4 -.IX Item "-mno-multm" -Do not generate multm or multmu instructions. This is useful for some embedded -systems which do not have trap handlers for these instructions. +These switches are supported in addition to the above on Solaris: +.IP "\fB\-threads\fR" 4 +.IX Item "-threads" +Add support for multithreading using the Solaris threads library. This +option sets flags for both the preprocessor and linker. This option does +not affect the thread safety of object code produced by the compiler or +that of libraries supplied with it. +.IP "\fB\-pthreads\fR" 4 +.IX Item "-pthreads" +Add support for multithreading using the \s-1POSIX\s0 threads library. This +option sets flags for both the preprocessor and linker. This option does +not affect the thread safety of object code produced by the compiler or +that of libraries supplied with it. .PP -.I "\s-1ARM\s0 Options" +\fI\s-1ARM\s0 Options\fR .IX Subsection "ARM Options" .PP These \fB\-m\fR options are defined for Advanced \s-1RISC\s0 Machines (\s-1ARM\s0) architectures: -.Ip "\fB\-mapcs-frame\fR" 4 +.IP "\fB\-mapcs\-frame\fR" 4 .IX Item "-mapcs-frame" Generate a stack frame that is compliant with the \s-1ARM\s0 Procedure Call Standard for all functions, even if this is not strictly necessary for -correct execution of the code. Specifying \fB\-fomit-frame-pointer\fR +correct execution of the code. Specifying \fB\-fomit\-frame\-pointer\fR with this option will cause the stack frames not to be generated for -leaf functions. The default is \fB\-mno-apcs-frame\fR. -.Ip "\fB\-mapcs\fR" 4 +leaf functions. The default is \fB\-mno\-apcs\-frame\fR. +.IP "\fB\-mapcs\fR" 4 .IX Item "-mapcs" -This is a synonym for \fB\-mapcs-frame\fR. -.Ip "\fB\-mapcs-26\fR" 4 +This is a synonym for \fB\-mapcs\-frame\fR. +.IP "\fB\-mapcs\-26\fR" 4 .IX Item "-mapcs-26" Generate code for a processor running with a 26\-bit program counter, and conforming to the function calling standards for the \s-1APCS\s0 26\-bit -option. This option replaces the \fB\-m2\fR and \fB\-m3\fR options -of previous releases of the compiler. -.Ip "\fB\-mapcs-32\fR" 4 +option. +.Sp +This option is deprecated. Future releases of the \s-1GCC\s0 will only support +generating code that runs in apcs\-32 mode. +.IP "\fB\-mapcs\-32\fR" 4 .IX Item "-mapcs-32" Generate code for a processor running with a 32\-bit program counter, and conforming to the function calling standards for the \s-1APCS\s0 32\-bit -option. This option replaces the \fB\-m6\fR option of previous releases -of the compiler. -.Ip "\fB\-mthumb-interwork\fR" 4 +option. +.Sp +This flag is deprecated. Future releases of \s-1GCC\s0 will make this flag +unconditional. +.IP "\fB\-mthumb\-interwork\fR" 4 .IX Item "-mthumb-interwork" Generate code which supports calling between the \s-1ARM\s0 and Thumb instruction sets. Without this option the two instruction sets cannot be reliably used inside one program. The default is -\&\fB\-mno-thumb-interwork\fR, since slightly larger code is generated -when \fB\-mthumb-interwork\fR is specified. -.Ip "\fB\-mno-sched-prolog\fR" 4 +\&\fB\-mno\-thumb\-interwork\fR, since slightly larger code is generated +when \fB\-mthumb\-interwork\fR is specified. +.IP "\fB\-mno\-sched\-prolog\fR" 4 .IX Item "-mno-sched-prolog" Prevent the reordering of instructions in the function prolog, or the merging of those instruction with the instructions in the function's @@ -5195,34 +6079,34 @@ body. This means that all functions will start with a recognizable set of instructions (or in fact one of a choice from a small set of different function prologues), and this information can be used to locate the start if functions inside an executable piece of code. The -default is \fB\-msched-prolog\fR. -.Ip "\fB\-mhard-float\fR" 4 +default is \fB\-msched\-prolog\fR. +.IP "\fB\-mhard\-float\fR" 4 .IX Item "-mhard-float" Generate output containing floating point instructions. This is the default. -.Ip "\fB\-msoft-float\fR" 4 +.IP "\fB\-msoft\-float\fR" 4 .IX Item "-msoft-float" Generate output containing library calls for floating point. \&\fBWarning:\fR the requisite libraries are not available for all \s-1ARM\s0 targets. Normally the facilities of the machine's usual C compiler are -used, but this cannot be done directly in cross-compilation. You must make +used, but this cannot be done directly in cross\-compilation. You must make your own arrangements to provide suitable library functions for -cross-compilation. +cross\-compilation. .Sp -\&\fB\-msoft-float\fR changes the calling convention in the output file; +\&\fB\-msoft\-float\fR changes the calling convention in the output file; therefore, it is only useful if you compile \fIall\fR of a program with this option. In particular, you need to compile \fIlibgcc.a\fR, the -library that comes with \s-1GCC\s0, with \fB\-msoft-float\fR in order for +library that comes with \s-1GCC\s0, with \fB\-msoft\-float\fR in order for this to work. -.Ip "\fB\-mlittle-endian\fR" 4 +.IP "\fB\-mlittle\-endian\fR" 4 .IX Item "-mlittle-endian" Generate code for a processor running in little-endian mode. This is the default for all standard configurations. -.Ip "\fB\-mbig-endian\fR" 4 +.IP "\fB\-mbig\-endian\fR" 4 .IX Item "-mbig-endian" Generate code for a processor running in big-endian mode; the default is to compile code for a little-endian processor. -.Ip "\fB\-mwords-little-endian\fR" 4 +.IP "\fB\-mwords\-little\-endian\fR" 4 .IX Item "-mwords-little-endian" This option only applies when generating code for big-endian processors. Generate code for a little-endian word order but a big-endian byte @@ -5230,7 +6114,7 @@ order. That is, a byte order of the form \fB32107654\fR. Note: this option should only be used if you require compatibility with code for big-endian \s-1ARM\s0 processors generated by versions of the compiler prior to 2.8. -.Ip "\fB\-malignment-traps\fR" 4 +.IP "\fB\-malignment\-traps\fR" 4 .IX Item "-malignment-traps" Generate code that will not trap if the \s-1MMU\s0 has alignment traps enabled. On \s-1ARM\s0 architectures prior to ARMv4, there were no instructions to @@ -5239,14 +6123,14 @@ memory a feature of the \s-1ARM\s0 architecture allows a word load to be used, even if the address is unaligned, and the processor core will rotate the data as it is being loaded. This option tells the compiler that such misaligned accesses will cause a \s-1MMU\s0 trap and that it should instead -synthesise the access as a series of byte accesses. The compiler can +synthesize the access as a series of byte accesses. The compiler can still use word accesses to load half-word data if it knows that the address is aligned to a word boundary. .Sp -This option is ignored when compiling for \s-1ARM\s0 architecture 4 or later, +This option has no effect when compiling for \s-1ARM\s0 architecture 4 or later, since these processors have instructions to directly access half-word objects in memory. -.Ip "\fB\-mno-alignment-traps\fR" 4 +.IP "\fB\-mno\-alignment\-traps\fR" 4 .IX Item "-mno-alignment-traps" Generate code that assumes that the \s-1MMU\s0 will not trap unaligned accesses. This produces better code when the target instruction set @@ -5257,40 +6141,12 @@ Note that you cannot use this option to access unaligned word objects, since the processor will only fetch one 32\-bit aligned object from memory. .Sp -The default setting for most targets is \fB\-mno-alignment-traps\fR, since -this produces better code when there are no half-word memory -instructions available. -.Ip "\fB\-mshort-load-bytes\fR" 4 -.IX Item "-mshort-load-bytes" -.PD 0 -.Ip "\fB\-mno-short-load-words\fR" 4 -.IX Item "-mno-short-load-words" -.PD -These are deprecated aliases for \fB\-malignment-traps\fR. -.Ip "\fB\-mno-short-load-bytes\fR" 4 -.IX Item "-mno-short-load-bytes" -.PD 0 -.Ip "\fB\-mshort-load-words\fR" 4 -.IX Item "-mshort-load-words" -.PD -This are deprecated aliases for \fB\-mno-alignment-traps\fR. -.Ip "\fB\-mbsd\fR" 4 -.IX Item "-mbsd" -This option only applies to \s-1RISC\s0 iX. Emulate the native BSD-mode -compiler. This is the default if \fB\-ansi\fR is not specified. -.Ip "\fB\-mxopen\fR" 4 -.IX Item "-mxopen" -This option only applies to \s-1RISC\s0 iX. Emulate the native X/Open-mode -compiler. -.Ip "\fB\-mno-symrename\fR" 4 -.IX Item "-mno-symrename" -This option only applies to \s-1RISC\s0 iX. Do not run the assembler -post-processor, \fBsymrename\fR, after code has been assembled. -Normally it is necessary to modify some of the standard symbols in -preparation for linking with the \s-1RISC\s0 iX C library; this option -suppresses this pass. The post-processor is never run when the -compiler is built for cross-compilation. -.Ip "\fB\-mcpu=\fR\fIname\fR" 4 +The default setting is \fB\-malignment\-traps\fR, since this produces +code that will also run on processors implementing \s-1ARM\s0 architecture +version 6 or later. +.Sp +This option is deprecated and will be removed in the next release of \s-1GCC\s0. +.IP "\fB\-mcpu=\fR\fIname\fR" 4 .IX Item "-mcpu=name" This specifies the name of the target \s-1ARM\s0 processor. \s-1GCC\s0 uses this name to determine what kind of instructions it can emit when generating @@ -5302,9 +6158,11 @@ assembly code. Permissible names are: \fBarm2\fR, \fBarm250\fR, \&\fBarm7500\fR, \fBarm7500fe\fR, \fBarm7tdmi\fR, \fBarm8\fR, \&\fBstrongarm\fR, \fBstrongarm110\fR, \fBstrongarm1100\fR, \&\fBarm8\fR, \fBarm810\fR, \fBarm9\fR, \fBarm9e\fR, \fBarm920\fR, -\&\fBarm920t\fR, \fBarm940t\fR, \fBarm9tdmi\fR, \fBarm10tdmi\fR, -\&\fBarm1020t\fR, \fBxscale\fR. -.Ip "\fB\-mtune=\fR\fIname\fR" 4 +\&\fBarm920t\fR, \fBarm926ejs\fR, \fBarm940t\fR, \fBarm9tdmi\fR, +\&\fBarm10tdmi\fR, \fBarm1020t\fR, \fBarm1026ejs\fR, +\&\fBarm1136js\fR, \fBarm1136jfs\fR ,\fBxscale\fR, \fBiwmmxt\fR, +\&\fBep9312\fR. +.IP "\fB\-mtune=\fR\fIname\fR" 4 .IX Item "-mtune=name" This option is very similar to the \fB\-mcpu=\fR option, except that instead of specifying the actual target processor type, and hence @@ -5314,24 +6172,25 @@ specified in this option, but still choosing the instructions that it will generate based on the cpu specified by a \fB\-mcpu=\fR option. For some \s-1ARM\s0 implementations better performance can be obtained by using this option. -.Ip "\fB\-march=\fR\fIname\fR" 4 +.IP "\fB\-march=\fR\fIname\fR" 4 .IX Item "-march=name" This specifies the name of the target \s-1ARM\s0 architecture. \s-1GCC\s0 uses this name to determine what kind of instructions it can emit when generating assembly code. This option can be used in conjunction with or instead of the \fB\-mcpu=\fR option. Permissible names are: \fBarmv2\fR, \&\fBarmv2a\fR, \fBarmv3\fR, \fBarmv3m\fR, \fBarmv4\fR, \fBarmv4t\fR, -\&\fBarmv5\fR, \fBarmv5t\fR, \fBarmv5te\fR. -.Ip "\fB\-mfpe=\fR\fInumber\fR" 4 +\&\fBarmv5\fR, \fBarmv5t\fR, \fBarmv5te\fR, \fBarmv6j\fR, +\&\fBiwmmxt\fR, \fBep9312\fR. +.IP "\fB\-mfpe=\fR\fInumber\fR" 4 .IX Item "-mfpe=number" .PD 0 -.Ip "\fB\-mfp=\fR\fInumber\fR" 4 +.IP "\fB\-mfp=\fR\fInumber\fR" 4 .IX Item "-mfp=number" .PD This specifies the version of the floating point emulation available on the target. Permissible values are 2 and 3. \fB\-mfp=\fR is a synonym for \fB\-mfpe=\fR, for compatibility with older versions of \s-1GCC\s0. -.Ip "\fB\-mstructure-size-boundary=\fR\fIn\fR" 4 +.IP "\fB\-mstructure\-size\-boundary=\fR\fIn\fR" 4 .IX Item "-mstructure-size-boundary=n" The size of all structures and unions will be rounded up to a multiple of the number of bits set by this option. Permissible values are 8 and @@ -5342,15 +6201,15 @@ of the program. The two values are potentially incompatible. Code compiled with one value cannot necessarily expect to work with code or libraries compiled with the other value, if they exchange information using structures or unions. -.Ip "\fB\-mabort-on-noreturn\fR" 4 +.IP "\fB\-mabort\-on\-noreturn\fR" 4 .IX Item "-mabort-on-noreturn" Generate a call to the function \f(CW\*(C`abort\*(C'\fR at the end of a \&\f(CW\*(C`noreturn\*(C'\fR function. It will be executed if the function tries to return. -.Ip "\fB\-mlong-calls\fR" 4 +.IP "\fB\-mlong\-calls\fR" 4 .IX Item "-mlong-calls" .PD 0 -.Ip "\fB\-mno-long-calls\fR" 4 +.IP "\fB\-mno\-long\-calls\fR" 4 .IX Item "-mno-long-calls" .PD Tells the compiler to perform function calls by first loading the @@ -5371,25 +6230,35 @@ the scope of a \fB#pragma long_calls\fR directive, will always be turned into long calls. .Sp This feature is not enabled by default. Specifying -\&\fB\-mno-long-calls\fR will restore the default behavior, as will +\&\fB\-mno\-long\-calls\fR will restore the default behavior, as will placing the function calls within the scope of a \fB#pragma long_calls_off\fR directive. Note these switches have no effect on how the compiler generates code to handle function calls via function pointers. -.Ip "\fB\-mnop-fun-dllimport\fR" 4 +.IP "\fB\-mnop\-fun\-dllimport\fR" 4 .IX Item "-mnop-fun-dllimport" Disable support for the \f(CW\*(C`dllimport\*(C'\fR attribute. -.Ip "\fB\-msingle-pic-base\fR" 4 +.IP "\fB\-msingle\-pic\-base\fR" 4 .IX Item "-msingle-pic-base" -Treat the register used for \s-1PIC\s0 addressing as read-only, rather than +Treat the register used for \s-1PIC\s0 addressing as read\-only, rather than loading it in the prologue for each function. The run-time system is responsible for initializing this register with an appropriate value before execution begins. -.Ip "\fB\-mpic-register=\fR\fIreg\fR" 4 +.IP "\fB\-mpic\-register=\fR\fIreg\fR" 4 .IX Item "-mpic-register=reg" Specify the register to be used for \s-1PIC\s0 addressing. The default is R10 unless stack-checking is enabled, when R9 is used. -.Ip "\fB\-mpoke-function-name\fR" 4 +.IP "\fB\-mcirrus\-fix\-invalid\-insns\fR" 4 +.IX Item "-mcirrus-fix-invalid-insns" +Insert NOPs into the instruction stream to in order to work around +problems with invalid Maverick instruction combinations. This option +is only valid if the \fB\-mcpu=ep9312\fR option has been used to +enable generation of instructions for the Cirrus Maverick floating +point co\-processor. This option is not enabled by default, since the +problem is only present in older Maverick implementations. The default +can be re-enabled by use of the \fB\-mno\-cirrus\-fix\-invalid\-insns\fR +switch. +.IP "\fB\-mpoke\-function\-name\fR" 4 .IX Item "-mpoke-function-name" Write the name of each function into the text section, directly preceding the function prologue. The generated code is similar to this: @@ -5405,73 +6274,62 @@ preceding the function prologue. The generated code is similar to this: \& stmfd sp!, {fp, ip, lr, pc} \& sub fp, ip, #4 .Ve +.Sp When performing a stack backtrace, code can inspect the value of \&\f(CW\*(C`pc\*(C'\fR stored at \f(CW\*(C`fp + 0\*(C'\fR. If the trace function then looks at location \f(CW\*(C`pc \- 12\*(C'\fR and the top 8 bits are set, then we know that there is a function name embedded immediately preceding this location and has length \f(CW\*(C`((pc[\-3]) & 0xff000000)\*(C'\fR. -.Ip "\fB\-mthumb\fR" 4 +.IP "\fB\-mthumb\fR" 4 .IX Item "-mthumb" Generate code for the 16\-bit Thumb instruction set. The default is to use the 32\-bit \s-1ARM\s0 instruction set. -.Ip "\fB\-mtpcs-frame\fR" 4 +.IP "\fB\-mtpcs\-frame\fR" 4 .IX Item "-mtpcs-frame" Generate a stack frame that is compliant with the Thumb Procedure Call Standard for all non-leaf functions. (A leaf function is one that does -not call any other functions.) The default is \fB\-mno-tpcs-frame\fR. -.Ip "\fB\-mtpcs-leaf-frame\fR" 4 +not call any other functions.) The default is \fB\-mno\-tpcs\-frame\fR. +.IP "\fB\-mtpcs\-leaf\-frame\fR" 4 .IX Item "-mtpcs-leaf-frame" Generate a stack frame that is compliant with the Thumb Procedure Call Standard for all leaf functions. (A leaf function is one that does -not call any other functions.) The default is \fB\-mno-apcs-leaf-frame\fR. -.Ip "\fB\-mcallee-super-interworking\fR" 4 +not call any other functions.) The default is \fB\-mno\-apcs\-leaf\-frame\fR. +.IP "\fB\-mcallee\-super\-interworking\fR" 4 .IX Item "-mcallee-super-interworking" Gives all externally visible functions in the file being compiled an \s-1ARM\s0 instruction set header which switches to Thumb mode before executing the rest of the function. This allows these functions to be called from non-interworking code. -.Ip "\fB\-mcaller-super-interworking\fR" 4 +.IP "\fB\-mcaller\-super\-interworking\fR" 4 .IX Item "-mcaller-super-interworking" Allows calls via function pointers (including virtual functions) to execute correctly regardless of whether the target code has been compiled for interworking or not. There is a small overhead in the cost of executing a function pointer if this option is enabled. .PP -.I "\s-1MN10200\s0 Options" -.IX Subsection "MN10200 Options" -.PP -These \fB\-m\fR options are defined for Matsushita \s-1MN10200\s0 architectures: -.Ip "\fB\-mrelax\fR" 4 -.IX Item "-mrelax" -Indicate to the linker that it should perform a relaxation optimization pass -to shorten branches, calls and absolute memory addresses. This option only -has an effect when used on the command line for the final link step. -.Sp -This option makes symbolic debugging impossible. -.PP -.I "\s-1MN10300\s0 Options" +\fI\s-1MN10300\s0 Options\fR .IX Subsection "MN10300 Options" .PP These \fB\-m\fR options are defined for Matsushita \s-1MN10300\s0 architectures: -.Ip "\fB\-mmult-bug\fR" 4 +.IP "\fB\-mmult\-bug\fR" 4 .IX Item "-mmult-bug" Generate code to avoid bugs in the multiply instructions for the \s-1MN10300\s0 processors. This is the default. -.Ip "\fB\-mno-mult-bug\fR" 4 +.IP "\fB\-mno\-mult\-bug\fR" 4 .IX Item "-mno-mult-bug" Do not generate code to avoid bugs in the multiply instructions for the \&\s-1MN10300\s0 processors. -.Ip "\fB\-mam33\fR" 4 +.IP "\fB\-mam33\fR" 4 .IX Item "-mam33" Generate code which uses features specific to the \s-1AM33\s0 processor. -.Ip "\fB\-mno-am33\fR" 4 +.IP "\fB\-mno\-am33\fR" 4 .IX Item "-mno-am33" Do not generate code which uses features specific to the \s-1AM33\s0 processor. This is the default. -.Ip "\fB\-mno-crt0\fR" 4 +.IP "\fB\-mno\-crt0\fR" 4 .IX Item "-mno-crt0" Do not link in the C run-time initialization object file. -.Ip "\fB\-mrelax\fR" 4 +.IP "\fB\-mrelax\fR" 4 .IX Item "-mrelax" Indicate to the linker that it should perform a relaxation optimization pass to shorten branches, calls and absolute memory addresses. This option only @@ -5479,18 +6337,21 @@ has an effect when used on the command line for the final link step. .Sp This option makes symbolic debugging impossible. .PP -.I "M32R/D Options" +\fIM32R/D Options\fR .IX Subsection "M32R/D Options" .PP -These \fB\-m\fR options are defined for Mitsubishi M32R/D architectures: -.Ip "\fB\-m32rx\fR" 4 +These \fB\-m\fR options are defined for Renesas M32R/D architectures: +.IP "\fB\-m32r2\fR" 4 +.IX Item "-m32r2" +Generate code for the M32R/2. +.IP "\fB\-m32rx\fR" 4 .IX Item "-m32rx" Generate code for the M32R/X. -.Ip "\fB\-m32r\fR" 4 +.IP "\fB\-m32r\fR" 4 .IX Item "-m32r" Generate code for the M32R. This is the default. -.Ip "\fB\-mcode-model=small\fR" 4 -.IX Item "-mcode-model=small" +.IP "\fB\-mmodel=small\fR" 4 +.IX Item "-mmodel=small" Assume all objects live in the lower 16MB of memory (so that their addresses can be loaded with the \f(CW\*(C`ld24\*(C'\fR instruction), and assume all subroutines are reachable with the \f(CW\*(C`bl\*(C'\fR instruction. @@ -5498,19 +6359,19 @@ This is the default. .Sp The addressability of a particular object can be set with the \&\f(CW\*(C`model\*(C'\fR attribute. -.Ip "\fB\-mcode-model=medium\fR" 4 -.IX Item "-mcode-model=medium" +.IP "\fB\-mmodel=medium\fR" 4 +.IX Item "-mmodel=medium" Assume objects may be anywhere in the 32\-bit address space (the compiler will generate \f(CW\*(C`seth/add3\*(C'\fR instructions to load their addresses), and assume all subroutines are reachable with the \f(CW\*(C`bl\*(C'\fR instruction. -.Ip "\fB\-mcode-model=large\fR" 4 -.IX Item "-mcode-model=large" +.IP "\fB\-mmodel=large\fR" 4 +.IX Item "-mmodel=large" Assume objects may be anywhere in the 32\-bit address space (the compiler will generate \f(CW\*(C`seth/add3\*(C'\fR instructions to load their addresses), and assume subroutines may not be reachable with the \f(CW\*(C`bl\*(C'\fR instruction (the compiler will generate the much slower \f(CW\*(C`seth/add3/jl\*(C'\fR instruction sequence). -.Ip "\fB\-msdata=none\fR" 4 +.IP "\fB\-msdata=none\fR" 4 .IX Item "-msdata=none" Disable use of the small data area. Variables will be put into one of \fB.data\fR, \fBbss\fR, or \fB.rodata\fR (unless the @@ -5520,15 +6381,15 @@ This is the default. The small data area consists of sections \fB.sdata\fR and \fB.sbss\fR. Objects may be explicitly put in the small data area with the \&\f(CW\*(C`section\*(C'\fR attribute using one of these sections. -.Ip "\fB\-msdata=sdata\fR" 4 +.IP "\fB\-msdata=sdata\fR" 4 .IX Item "-msdata=sdata" Put small global and static data in the small data area, but do not generate special code to reference them. -.Ip "\fB\-msdata=use\fR" 4 +.IP "\fB\-msdata=use\fR" 4 .IX Item "-msdata=use" Put small global and static data in the small data area, and generate special instructions to reference them. -.Ip "\fB\-G\fR \fInum\fR" 4 +.IP "\fB\-G\fR \fInum\fR" 4 .IX Item "-G num" Put global and static objects less than or equal to \fInum\fR bytes into the small data or bss sections instead of the normal data or bss @@ -5540,232 +6401,69 @@ All modules should be compiled with the same \fB\-G\fR \fInum\fR value. Compiling with different values of \fInum\fR may or may not work; if it doesn't the linker will give an error message\-\-\-incorrect code will not be generated. +.IP "\fB\-mdebug\fR" 4 +.IX Item "-mdebug" +Makes the M32R specific code in the compiler display some statistics +that might help in debugging programs. +.IP "\fB\-malign\-loops\fR" 4 +.IX Item "-malign-loops" +Align all loops to a 32\-byte boundary. +.IP "\fB\-mno\-align\-loops\fR" 4 +.IX Item "-mno-align-loops" +Do not enforce a 32\-byte alignment for loops. This is the default. +.IP "\fB\-missue\-rate=\fR\fInumber\fR" 4 +.IX Item "-missue-rate=number" +Issue \fInumber\fR instructions per cycle. \fInumber\fR can only be 1 +or 2. +.IP "\fB\-mbranch\-cost=\fR\fInumber\fR" 4 +.IX Item "-mbranch-cost=number" +\&\fInumber\fR can only be 1 or 2. If it is 1 then branches will be +preferred over conditional code, if it is 2, then the opposite will +apply. +.IP "\fB\-mflush\-trap=\fR\fInumber\fR" 4 +.IX Item "-mflush-trap=number" +Specifies the trap number to use to flush the cache. The default is +12. Valid numbers are between 0 and 15 inclusive. +.IP "\fB\-mno\-flush\-trap\fR" 4 +.IX Item "-mno-flush-trap" +Specifies that the cache cannot be flushed by using a trap. +.IP "\fB\-mflush\-func=\fR\fIname\fR" 4 +.IX Item "-mflush-func=name" +Specifies the name of the operating system function to call to flush +the cache. The default is \fI_flush_cache\fR, but a function call +will only be used if a trap is not available. +.IP "\fB\-mno\-flush\-func\fR" 4 +.IX Item "-mno-flush-func" +Indicates that there is no \s-1OS\s0 function for flushing the cache. .PP -.I "M88K Options" -.IX Subsection "M88K Options" -.PP -These \fB\-m\fR options are defined for Motorola 88k architectures: -.Ip "\fB\-m88000\fR" 4 -.IX Item "-m88000" -Generate code that works well on both the m88100 and the -m88110. -.Ip "\fB\-m88100\fR" 4 -.IX Item "-m88100" -Generate code that works best for the m88100, but that also -runs on the m88110. -.Ip "\fB\-m88110\fR" 4 -.IX Item "-m88110" -Generate code that works best for the m88110, and may not run -on the m88100. -.Ip "\fB\-mbig-pic\fR" 4 -.IX Item "-mbig-pic" -Obsolete option to be removed from the next revision. -Use \fB\-fPIC\fR. -.Ip "\fB\-midentify-revision\fR" 4 -.IX Item "-midentify-revision" -Include an \f(CW\*(C`ident\*(C'\fR directive in the assembler output recording the -source file name, compiler name and version, timestamp, and compilation -flags used. -.Ip "\fB\-mno-underscores\fR" 4 -.IX Item "-mno-underscores" -In assembler output, emit symbol names without adding an underscore -character at the beginning of each name. The default is to use an -underscore as prefix on each name. -.Ip "\fB\-mocs-debug-info\fR" 4 -.IX Item "-mocs-debug-info" -.PD 0 -.Ip "\fB\-mno-ocs-debug-info\fR" 4 -.IX Item "-mno-ocs-debug-info" -.PD -Include (or omit) additional debugging information (about registers used -in each stack frame) as specified in the 88open Object Compatibility -Standard, ``\s-1OCS\s0''. This extra information allows debugging of code that -has had the frame pointer eliminated. The default for \s-1DG/UX\s0, SVr4, and -Delta 88 SVr3.2 is to include this information; other 88k configurations -omit this information by default. -.Ip "\fB\-mocs-frame-position\fR" 4 -.IX Item "-mocs-frame-position" -When emitting \s-1COFF\s0 debugging information for automatic variables and -parameters stored on the stack, use the offset from the canonical frame -address, which is the stack pointer (register 31) on entry to the -function. The \s-1DG/UX\s0, SVr4, Delta88 SVr3.2, and \s-1BCS\s0 configurations use -\&\fB\-mocs-frame-position\fR; other 88k configurations have the default -\&\fB\-mno-ocs-frame-position\fR. -.Ip "\fB\-mno-ocs-frame-position\fR" 4 -.IX Item "-mno-ocs-frame-position" -When emitting \s-1COFF\s0 debugging information for automatic variables and -parameters stored on the stack, use the offset from the frame pointer -register (register 30). When this option is in effect, the frame -pointer is not eliminated when debugging information is selected by the -\&\-g switch. -.Ip "\fB\-moptimize-arg-area\fR" 4 -.IX Item "-moptimize-arg-area" -Save space by reorganizing the stack frame. This option generates code -that does not agree with the 88open specifications, but uses less -memory. -.Ip "\fB\-mno-optimize-arg-area\fR" 4 -.IX Item "-mno-optimize-arg-area" -Do not reorganize the stack frame to save space. This is the default. -The generated conforms to the specification, but uses more memory. -.Ip "\fB\-mshort-data-\fR\fInum\fR" 4 -.IX Item "-mshort-data-num" -Generate smaller data references by making them relative to \f(CW\*(C`r0\*(C'\fR, -which allows loading a value using a single instruction (rather than the -usual two). You control which data references are affected by -specifying \fInum\fR with this option. For example, if you specify -\&\fB\-mshort-data-512\fR, then the data references affected are those -involving displacements of less than 512 bytes. -\&\fB\-mshort-data-\fR\fInum\fR is not effective for \fInum\fR greater -than 64k. -.Ip "\fB\-mserialize-volatile\fR" 4 -.IX Item "-mserialize-volatile" -.PD 0 -.Ip "\fB\-mno-serialize-volatile\fR" 4 -.IX Item "-mno-serialize-volatile" -.PD -Do, or don't, generate code to guarantee sequential consistency -of volatile memory references. By default, consistency is -guaranteed. -.Sp -The order of memory references made by the \s-1MC88110\s0 processor does -not always match the order of the instructions requesting those -references. In particular, a load instruction may execute before -a preceding store instruction. Such reordering violates -sequential consistency of volatile memory references, when there -are multiple processors. When consistency must be guaranteed, -\&\s-1GCC\s0 generates special instructions, as needed, to force -execution in the proper order. -.Sp -The \s-1MC88100\s0 processor does not reorder memory references and so -always provides sequential consistency. However, by default, \s-1GCC\s0 -generates the special instructions to guarantee consistency -even when you use \fB\-m88100\fR, so that the code may be run on an -\&\s-1MC88110\s0 processor. If you intend to run your code only on the -\&\s-1MC88100\s0 processor, you may use \fB\-mno-serialize-volatile\fR. -.Sp -The extra code generated to guarantee consistency may affect the -performance of your application. If you know that you can safely -forgo this guarantee, you may use \fB\-mno-serialize-volatile\fR. -.Ip "\fB\-msvr4\fR" 4 -.IX Item "-msvr4" -.PD 0 -.Ip "\fB\-msvr3\fR" 4 -.IX Item "-msvr3" -.PD -Turn on (\fB\-msvr4\fR) or off (\fB\-msvr3\fR) compiler extensions -related to System V release 4 (SVr4). This controls the following: -.RS 4 -.Ip "1." 4 -Which variant of the assembler syntax to emit. -.Ip "2." 4 -\&\fB\-msvr4\fR makes the C preprocessor recognize \fB#pragma weak\fR -that is used on System V release 4. -.Ip "3." 4 -\&\fB\-msvr4\fR makes \s-1GCC\s0 issue additional declaration directives used in -SVr4. -.RE -.RS 4 -.Sp -\&\fB\-msvr4\fR is the default for the m88k-motorola-sysv4 and -m88k-dg-dgux m88k configurations. \fB\-msvr3\fR is the default for all -other m88k configurations. -.RE -.Ip "\fB\-mversion-03.00\fR" 4 -.IX Item "-mversion-03.00" -This option is obsolete, and is ignored. -.Ip "\fB\-mno-check-zero-division\fR" 4 -.IX Item "-mno-check-zero-division" -.PD 0 -.Ip "\fB\-mcheck-zero-division\fR" 4 -.IX Item "-mcheck-zero-division" -.PD -Do, or don't, generate code to guarantee that integer division by -zero will be detected. By default, detection is guaranteed. -.Sp -Some models of the \s-1MC88100\s0 processor fail to trap upon integer -division by zero under certain conditions. By default, when -compiling code that might be run on such a processor, \s-1GCC\s0 -generates code that explicitly checks for zero-valued divisors -and traps with exception number 503 when one is detected. Use of -\&\fB\-mno-check-zero-division\fR suppresses such checking for code -generated to run on an \s-1MC88100\s0 processor. -.Sp -\&\s-1GCC\s0 assumes that the \s-1MC88110\s0 processor correctly detects all instances -of integer division by zero. When \fB\-m88110\fR is specified, no -explicit checks for zero-valued divisors are generated, and both -\&\fB\-mcheck-zero-division\fR and \fB\-mno-check-zero-division\fR are -ignored. -.Ip "\fB\-muse-div-instruction\fR" 4 -.IX Item "-muse-div-instruction" -Use the div instruction for signed integer division on the -\&\s-1MC88100\s0 processor. By default, the div instruction is not used. -.Sp -On the \s-1MC88100\s0 processor the signed integer division instruction -div) traps to the operating system on a negative operand. The -operating system transparently completes the operation, but at a -large cost in execution time. By default, when compiling code -that might be run on an \s-1MC88100\s0 processor, \s-1GCC\s0 emulates signed -integer division using the unsigned integer division instruction -divu), thereby avoiding the large penalty of a trap to the -operating system. Such emulation has its own, smaller, execution -cost in both time and space. To the extent that your code's -important signed integer division operations are performed on two -nonnegative operands, it may be desirable to use the div -instruction directly. -.Sp -On the \s-1MC88110\s0 processor the div instruction (also known as the -divs instruction) processes negative operands without trapping to -the operating system. When \fB\-m88110\fR is specified, -\&\fB\-muse-div-instruction\fR is ignored, and the div instruction is used -for signed integer division. -.Sp -Note that the result of dividing \f(CW\*(C`INT_MIN\*(C'\fR by \-1 is undefined. In -particular, the behavior of such a division with and without -\&\fB\-muse-div-instruction\fR may differ. -.Ip "\fB\-mtrap-large-shift\fR" 4 -.IX Item "-mtrap-large-shift" -.PD 0 -.Ip "\fB\-mhandle-large-shift\fR" 4 -.IX Item "-mhandle-large-shift" -.PD -Include code to detect bit-shifts of more than 31 bits; respectively, -trap such shifts or emit code to handle them properly. By default \s-1GCC\s0 -makes no special provision for large bit shifts. -.Ip "\fB\-mwarn-passed-structs\fR" 4 -.IX Item "-mwarn-passed-structs" -Warn when a function passes a struct as an argument or result. -Structure-passing conventions have changed during the evolution of the C -language, and are often the source of portability problems. By default, -\&\s-1GCC\s0 issues no such warning. -.PP -.I "\s-1IBM\s0 \s-1RS/6000\s0 and PowerPC Options" +\fI\s-1IBM\s0 \s-1RS/6000\s0 and PowerPC Options\fR .IX Subsection "IBM RS/6000 and PowerPC Options" .PP These \fB\-m\fR options are defined for the \s-1IBM\s0 \s-1RS/6000\s0 and PowerPC: -.Ip "\fB\-mpower\fR" 4 +.IP "\fB\-mpower\fR" 4 .IX Item "-mpower" .PD 0 -.Ip "\fB\-mno-power\fR" 4 +.IP "\fB\-mno\-power\fR" 4 .IX Item "-mno-power" -.Ip "\fB\-mpower2\fR" 4 +.IP "\fB\-mpower2\fR" 4 .IX Item "-mpower2" -.Ip "\fB\-mno-power2\fR" 4 +.IP "\fB\-mno\-power2\fR" 4 .IX Item "-mno-power2" -.Ip "\fB\-mpowerpc\fR" 4 +.IP "\fB\-mpowerpc\fR" 4 .IX Item "-mpowerpc" -.Ip "\fB\-mno-powerpc\fR" 4 +.IP "\fB\-mno\-powerpc\fR" 4 .IX Item "-mno-powerpc" -.Ip "\fB\-mpowerpc-gpopt\fR" 4 +.IP "\fB\-mpowerpc\-gpopt\fR" 4 .IX Item "-mpowerpc-gpopt" -.Ip "\fB\-mno-powerpc-gpopt\fR" 4 +.IP "\fB\-mno\-powerpc\-gpopt\fR" 4 .IX Item "-mno-powerpc-gpopt" -.Ip "\fB\-mpowerpc-gfxopt\fR" 4 +.IP "\fB\-mpowerpc\-gfxopt\fR" 4 .IX Item "-mpowerpc-gfxopt" -.Ip "\fB\-mno-powerpc-gfxopt\fR" 4 +.IP "\fB\-mno\-powerpc\-gfxopt\fR" 4 .IX Item "-mno-powerpc-gfxopt" -.Ip "\fB\-mpowerpc64\fR" 4 +.IP "\fB\-mpowerpc64\fR" 4 .IX Item "-mpowerpc64" -.Ip "\fB\-mno-powerpc64\fR" 4 +.IP "\fB\-mno\-powerpc64\fR" 4 .IX Item "-mno-powerpc64" .PD \&\s-1GCC\s0 supports two related instruction set architectures for the @@ -5794,52 +6492,55 @@ not the original \s-1POWER\s0 architecture. .Sp The \fB\-mpowerpc\fR option allows \s-1GCC\s0 to generate instructions that are found only in the 32\-bit subset of the PowerPC architecture. -Specifying \fB\-mpowerpc-gpopt\fR implies \fB\-mpowerpc\fR and also allows +Specifying \fB\-mpowerpc\-gpopt\fR implies \fB\-mpowerpc\fR and also allows \&\s-1GCC\s0 to use the optional PowerPC architecture instructions in the General Purpose group, including floating-point square root. Specifying -\&\fB\-mpowerpc-gfxopt\fR implies \fB\-mpowerpc\fR and also allows \s-1GCC\s0 to +\&\fB\-mpowerpc\-gfxopt\fR implies \fB\-mpowerpc\fR and also allows \s-1GCC\s0 to use the optional PowerPC architecture instructions in the Graphics group, including floating-point select. .Sp The \fB\-mpowerpc64\fR option allows \s-1GCC\s0 to generate the additional 64\-bit instructions that are found in the full PowerPC64 architecture and to treat GPRs as 64\-bit, doubleword quantities. \s-1GCC\s0 defaults to -\&\fB\-mno-powerpc64\fR. +\&\fB\-mno\-powerpc64\fR. .Sp -If you specify both \fB\-mno-power\fR and \fB\-mno-powerpc\fR, \s-1GCC\s0 +If you specify both \fB\-mno\-power\fR and \fB\-mno\-powerpc\fR, \s-1GCC\s0 will use only the instructions in the common subset of both architectures plus some special \s-1AIX\s0 common-mode calls, and will not use the \s-1MQ\s0 register. Specifying both \fB\-mpower\fR and \fB\-mpowerpc\fR permits \s-1GCC\s0 to use any instruction from either architecture and to allow use of the \s-1MQ\s0 register; specify this for the Motorola \s-1MPC601\s0. -.Ip "\fB\-mnew-mnemonics\fR" 4 +.IP "\fB\-mnew\-mnemonics\fR" 4 .IX Item "-mnew-mnemonics" .PD 0 -.Ip "\fB\-mold-mnemonics\fR" 4 +.IP "\fB\-mold\-mnemonics\fR" 4 .IX Item "-mold-mnemonics" .PD Select which mnemonics to use in the generated assembler code. With -\&\fB\-mnew-mnemonics\fR, \s-1GCC\s0 uses the assembler mnemonics defined for -the PowerPC architecture. With \fB\-mold-mnemonics\fR it uses the +\&\fB\-mnew\-mnemonics\fR, \s-1GCC\s0 uses the assembler mnemonics defined for +the PowerPC architecture. With \fB\-mold\-mnemonics\fR it uses the assembler mnemonics defined for the \s-1POWER\s0 architecture. Instructions defined in only one architecture have only one mnemonic; \s-1GCC\s0 uses that mnemonic irrespective of which of these options is specified. .Sp \&\s-1GCC\s0 defaults to the mnemonics appropriate for the architecture in use. Specifying \fB\-mcpu=\fR\fIcpu_type\fR sometimes overrides the -value of these option. Unless you are building a cross-compiler, you -should normally not specify either \fB\-mnew-mnemonics\fR or -\&\fB\-mold-mnemonics\fR, but should instead accept the default. -.Ip "\fB\-mcpu=\fR\fIcpu_type\fR" 4 +value of these option. Unless you are building a cross\-compiler, you +should normally not specify either \fB\-mnew\-mnemonics\fR or +\&\fB\-mold\-mnemonics\fR, but should instead accept the default. +.IP "\fB\-mcpu=\fR\fIcpu_type\fR" 4 .IX Item "-mcpu=cpu_type" Set architecture type, register usage, choice of mnemonics, and instruction scheduling parameters for machine type \fIcpu_type\fR. -Supported values for \fIcpu_type\fR are \fBrios\fR, \fBrios1\fR, -\&\fBrsc\fR, \fBrios2\fR, \fBrs64a\fR, \fB601\fR, \fB602\fR, -\&\fB603\fR, \fB603e\fR, \fB604\fR, \fB604e\fR, \fB620\fR, -\&\fB630\fR, \fB740\fR, \fB7400\fR, \fB7450\fR, \fB750\fR, -\&\fBpower\fR, \fBpower2\fR, \fBpowerpc\fR, \fB403\fR, \fB505\fR, -\&\fB801\fR, \fB821\fR, \fB823\fR, and \fB860\fR and \fBcommon\fR. +Supported values for \fIcpu_type\fR are \fB401\fR, \fB403\fR, +\&\fB405\fR, \fB405fp\fR, \fB440\fR, \fB440fp\fR, \fB505\fR, +\&\fB601\fR, \fB602\fR, \fB603\fR, \fB603e\fR, \fB604\fR, +\&\fB604e\fR, \fB620\fR, \fB630\fR, \fB740\fR, \fB7400\fR, +\&\fB7450\fR, \fB750\fR, \fB801\fR, \fB821\fR, \fB823\fR, +\&\fB860\fR, \fB970\fR, \fB8540\fR, \fBcommon\fR, \fBec603e\fR, \fBG3\fR, +\&\fBG4\fR, \fBG5\fR, \fBpower\fR, \fBpower2\fR, \fBpower3\fR, +\&\fBpower4\fR, \fBpower5\fR, \fBpowerpc\fR, \fBpowerpc64\fR, +\&\fBrios\fR, \fBrios1\fR, \fBrios2\fR, \fBrsc\fR, and \fBrs64a\fR. .Sp \&\fB\-mcpu=common\fR selects a completely generic processor. Code generated under this option will run on any \s-1POWER\s0 or PowerPC processor. @@ -5857,70 +6558,24 @@ The other options specify a specific processor. Code generated under those options will run best on that processor, and may not run at all on others. .Sp -The \fB\-mcpu\fR options automatically enable or disable other -\&\fB\-m\fR options as follows: -.RS 4 -.Ip "\fBcommon\fR" 4 -.IX Item "common" -\&\fB\-mno-power\fR, \fB\-mno-powerc\fR -.Ip "\fBpower\fR" 4 -.IX Item "power" -.PD 0 -.Ip "\fBpower2\fR" 4 -.IX Item "power2" -.Ip "\fBrios1\fR" 4 -.IX Item "rios1" -.Ip "\fBrios2\fR" 4 -.IX Item "rios2" -.Ip "\fBrsc\fR" 4 -.IX Item "rsc" -.PD -\&\fB\-mpower\fR, \fB\-mno-powerpc\fR, \fB\-mno-new-mnemonics\fR -.Ip "\fBpowerpc\fR" 4 -.IX Item "powerpc" -.PD 0 -.Ip "\fBrs64a\fR" 4 -.IX Item "rs64a" -.Ip "\fB602\fR" 4 -.IX Item "602" -.Ip "\fB603\fR" 4 -.IX Item "603" -.Ip "\fB603e\fR" 4 -.IX Item "603e" -.Ip "\fB604\fR" 4 -.IX Item "604" -.Ip "\fB620\fR" 4 -.IX Item "620" -.Ip "\fB630\fR" 4 -.IX Item "630" -.Ip "\fB740\fR" 4 -.IX Item "740" -.Ip "\fB7400\fR" 4 -.IX Item "7400" -.Ip "\fB7450\fR" 4 -.IX Item "7450" -.Ip "\fB750\fR" 4 -.IX Item "750" -.Ip "\fB505\fR" 4 -.IX Item "505" -.PD -\&\fB\-mno-power\fR, \fB\-mpowerpc\fR, \fB\-mnew-mnemonics\fR -.Ip "\fB601\fR" 4 -.IX Item "601" -\&\fB\-mpower\fR, \fB\-mpowerpc\fR, \fB\-mnew-mnemonics\fR -.Ip "\fB403\fR" 4 -.IX Item "403" -.PD 0 -.Ip "\fB821\fR" 4 -.IX Item "821" -.Ip "\fB860\fR" 4 -.IX Item "860" -.PD -\&\fB\-mno-power\fR, \fB\-mpowerpc\fR, \fB\-mnew-mnemonics\fR, \fB\-msoft-float\fR -.RE -.RS 4 -.RE -.Ip "\fB\-mtune=\fR\fIcpu_type\fR" 4 +The \fB\-mcpu\fR options automatically enable or disable the +following options: \fB\-maltivec\fR, \fB\-mhard\-float\fR, +\&\fB\-mmfcrf\fR, \fB\-mmultiple\fR, \fB\-mnew\-mnemonics\fR, +\&\fB\-mpower\fR, \fB\-mpower2\fR, \fB\-mpowerpc64\fR, +\&\fB\-mpowerpc\-gpopt\fR, \fB\-mpowerpc\-gfxopt\fR, +\&\fB\-mstring\fR. The particular options set for any particular \s-1CPU\s0 +will vary between compiler versions, depending on what setting seems +to produce optimal code for that \s-1CPU\s0; it doesn't necessarily reflect +the actual hardware's capabilities. If you wish to set an individual +option to a particular value, you may specify it after the +\&\fB\-mcpu\fR option, like \fB\-mcpu=970 \-mno\-altivec\fR. +.Sp +On \s-1AIX\s0, the \fB\-maltivec\fR and \fB\-mpowerpc64\fR options are +not enabled or disabled by the \fB\-mcpu\fR option at present, since +\&\s-1AIX\s0 does not have full support for these options. You may still +enable or disable them individually if you're sure it'll work in your +environment. +.IP "\fB\-mtune=\fR\fIcpu_type\fR" 4 .IX Item "-mtune=cpu_type" Set the instruction scheduling parameters for machine type \&\fIcpu_type\fR, but do not set the architecture type, register usage, or @@ -5929,28 +6584,60 @@ values for \fIcpu_type\fR are used for \fB\-mtune\fR as for \&\fB\-mcpu\fR. If both are specified, the code generated will use the architecture, registers, and mnemonics set by \fB\-mcpu\fR, but the scheduling parameters set by \fB\-mtune\fR. -.Ip "\fB\-maltivec\fR" 4 +.IP "\fB\-maltivec\fR" 4 .IX Item "-maltivec" .PD 0 -.Ip "\fB\-mno-altivec\fR" 4 +.IP "\fB\-mno\-altivec\fR" 4 .IX Item "-mno-altivec" .PD These switches enable or disable the use of built-in functions that allow access to the AltiVec instruction set. You may also need to set \&\fB\-mabi=altivec\fR to adjust the current \s-1ABI\s0 with AltiVec \s-1ABI\s0 enhancements. -.Ip "\fB\-mfull-toc\fR" 4 +.IP "\fB\-mabi=spe\fR" 4 +.IX Item "-mabi=spe" +Extend the current \s-1ABI\s0 with \s-1SPE\s0 \s-1ABI\s0 extensions. This does not change +the default \s-1ABI\s0, instead it adds the \s-1SPE\s0 \s-1ABI\s0 extensions to the current +\&\s-1ABI\s0. +.IP "\fB\-mabi=no\-spe\fR" 4 +.IX Item "-mabi=no-spe" +Disable Booke \s-1SPE\s0 \s-1ABI\s0 extensions for the current \s-1ABI\s0. +.IP "\fB\-misel=\fR\fIyes/no\fR" 4 +.IX Item "-misel=yes/no" +.PD 0 +.IP "\fB\-misel\fR" 4 +.IX Item "-misel" +.PD +This switch enables or disables the generation of \s-1ISEL\s0 instructions. +.IP "\fB\-mspe=\fR\fIyes/no\fR" 4 +.IX Item "-mspe=yes/no" +.PD 0 +.IP "\fB\-mspe\fR" 4 +.IX Item "-mspe" +.PD +This switch enables or disables the generation of \s-1SPE\s0 simd +instructions. +.IP "\fB\-mfloat\-gprs=\fR\fIyes/no\fR" 4 +.IX Item "-mfloat-gprs=yes/no" +.PD 0 +.IP "\fB\-mfloat\-gprs\fR" 4 +.IX Item "-mfloat-gprs" +.PD +This switch enables or disables the generation of floating point +operations on the general purpose registers for architectures that +support it. This option is currently only available on the \s-1MPC8540\s0. +.IP "\fB\-mfull\-toc\fR" 4 .IX Item "-mfull-toc" .PD 0 -.Ip "\fB\-mno-fp-in-toc\fR" 4 +.IP "\fB\-mno\-fp\-in\-toc\fR" 4 .IX Item "-mno-fp-in-toc" -.Ip "\fB\-mno-sum-in-toc\fR" 4 +.IP "\fB\-mno\-sum\-in\-toc\fR" 4 .IX Item "-mno-sum-in-toc" -.Ip "\fB\-mminimal-toc\fR" 4 +.IP "\fB\-mminimal\-toc\fR" 4 .IX Item "-mminimal-toc" .PD Modify generation of the \s-1TOC\s0 (Table Of Contents), which is created for -every executable file. The \fB\-mfull-toc\fR option is selected by +every executable file. The \fB\-mfull\-toc\fR option is selected by default. In that case, \s-1GCC\s0 will allocate at least one \s-1TOC\s0 entry for each unique non-automatic variable reference in your program. \s-1GCC\s0 will also place floating-point constants in the \s-1TOC\s0. However, only @@ -5958,40 +6645,44 @@ will also place floating-point constants in the \s-1TOC\s0. However, only .Sp If you receive a linker error message that saying you have overflowed the available \s-1TOC\s0 space, you can reduce the amount of \s-1TOC\s0 space used -with the \fB\-mno-fp-in-toc\fR and \fB\-mno-sum-in-toc\fR options. -\&\fB\-mno-fp-in-toc\fR prevents \s-1GCC\s0 from putting floating-point -constants in the \s-1TOC\s0 and \fB\-mno-sum-in-toc\fR forces \s-1GCC\s0 to +with the \fB\-mno\-fp\-in\-toc\fR and \fB\-mno\-sum\-in\-toc\fR options. +\&\fB\-mno\-fp\-in\-toc\fR prevents \s-1GCC\s0 from putting floating-point +constants in the \s-1TOC\s0 and \fB\-mno\-sum\-in\-toc\fR forces \s-1GCC\s0 to generate code to calculate the sum of an address and a constant at run-time instead of putting that sum into the \s-1TOC\s0. You may specify one or both of these options. Each causes \s-1GCC\s0 to produce very slightly slower and larger code at the expense of conserving \s-1TOC\s0 space. .Sp If you still run out of space in the \s-1TOC\s0 even when you specify both of -these options, specify \fB\-mminimal-toc\fR instead. This option causes +these options, specify \fB\-mminimal\-toc\fR instead. This option causes \&\s-1GCC\s0 to make only one \s-1TOC\s0 entry for every file. When you specify this option, \s-1GCC\s0 will produce code that is slower and larger but which uses extremely little \s-1TOC\s0 space. You may wish to use this option only on files that contain less frequently executed code. -.Ip "\fB\-maix64\fR" 4 +.IP "\fB\-maix64\fR" 4 .IX Item "-maix64" .PD 0 -.Ip "\fB\-maix32\fR" 4 +.IP "\fB\-maix32\fR" 4 .IX Item "-maix32" .PD Enable 64\-bit \s-1AIX\s0 \s-1ABI\s0 and calling convention: 64\-bit pointers, 64\-bit \&\f(CW\*(C`long\*(C'\fR type, and the infrastructure needed to support them. Specifying \fB\-maix64\fR implies \fB\-mpowerpc64\fR and \&\fB\-mpowerpc\fR, while \fB\-maix32\fR disables the 64\-bit \s-1ABI\s0 and -implies \fB\-mno-powerpc64\fR. \s-1GCC\s0 defaults to \fB\-maix32\fR. -.Ip "\fB\-mxl-call\fR" 4 -.IX Item "-mxl-call" +implies \fB\-mno\-powerpc64\fR. \s-1GCC\s0 defaults to \fB\-maix32\fR. +.IP "\fB\-mxl\-compat\fR" 4 +.IX Item "-mxl-compat" .PD 0 -.Ip "\fB\-mno-xl-call\fR" 4 -.IX Item "-mno-xl-call" +.IP "\fB\-mno\-xl\-compat\fR" 4 +.IX Item "-mno-xl-compat" .PD -On \s-1AIX\s0, pass floating-point arguments to prototyped functions beyond the -register save area (\s-1RSA\s0) on the stack in addition to argument FPRs. The -\&\s-1AIX\s0 calling convention was extended but not initially documented to +Produce code that conforms more closely to \s-1IBM\s0 \s-1XLC\s0 semantics when using +AIX-compatible \s-1ABI\s0. Pass floating-point arguments to prototyped +functions beyond the register save area (\s-1RSA\s0) on the stack in addition +to argument FPRs. Do not assume that most significant double in 128 +bit long double value is properly rounded when comparing values. +.Sp +The \s-1AIX\s0 calling convention was extended but not initially documented to handle an obscure K&R C case of calling a function that takes the address of its arguments with fewer arguments than declared. \s-1AIX\s0 \s-1XL\s0 compilers access floating point arguments which do not fit in the @@ -6000,7 +6691,7 @@ optimization. Because always storing floating-point arguments on the stack is inefficient and rarely needed, this option is not enabled by default and only is necessary when calling subroutines compiled by \s-1AIX\s0 \&\s-1XL\s0 compilers without optimization. -.Ip "\fB\-mpe\fR" 4 +.IP "\fB\-mpe\fR" 4 .IX Item "-mpe" Support \fI\s-1IBM\s0 \s-1RS/6000\s0 \s-1SP\s0\fR \fIParallel Environment\fR (\s-1PE\s0). Link an application written to use message passing with special startup code to @@ -6010,19 +6701,30 @@ must be overridden with the \fB\-specs=\fR option to specify the appropriate directory location. The Parallel Environment does not support threads, so the \fB\-mpe\fR option and the \fB\-pthread\fR option are incompatible. -.Ip "\fB\-msoft-float\fR" 4 +.IP "\fB\-malign\-natural\fR" 4 +.IX Item "-malign-natural" +.PD 0 +.IP "\fB\-malign\-power\fR" 4 +.IX Item "-malign-power" +.PD +On \s-1AIX\s0, Darwin, and 64\-bit PowerPC GNU/Linux, the option +\&\fB\-malign\-natural\fR overrides the ABI-defined alignment of larger +types, such as floating-point doubles, on their natural size-based boundary. +The option \fB\-malign\-power\fR instructs \s-1GCC\s0 to follow the ABI-specified +alignment rules. \s-1GCC\s0 defaults to the standard alignment defined in the \s-1ABI\s0. +.IP "\fB\-msoft\-float\fR" 4 .IX Item "-msoft-float" .PD 0 -.Ip "\fB\-mhard-float\fR" 4 +.IP "\fB\-mhard\-float\fR" 4 .IX Item "-mhard-float" .PD Generate code that does not use (uses) the floating-point register set. Software floating point emulation is provided if you use the -\&\fB\-msoft-float\fR option, and pass the option to \s-1GCC\s0 when linking. -.Ip "\fB\-mmultiple\fR" 4 +\&\fB\-msoft\-float\fR option, and pass the option to \s-1GCC\s0 when linking. +.IP "\fB\-mmultiple\fR" 4 .IX Item "-mmultiple" .PD 0 -.Ip "\fB\-mno-multiple\fR" 4 +.IP "\fB\-mno\-multiple\fR" 4 .IX Item "-mno-multiple" .PD Generate code that uses (does not use) the load multiple word @@ -6032,10 +6734,10 @@ generated on PowerPC systems. Do not use \fB\-mmultiple\fR on little endian PowerPC systems, since those instructions do not work when the processor is in little endian mode. The exceptions are \s-1PPC740\s0 and \&\s-1PPC750\s0 which permit the instructions usage in little endian mode. -.Ip "\fB\-mstring\fR" 4 +.IP "\fB\-mstring\fR" 4 .IX Item "-mstring" .PD 0 -.Ip "\fB\-mno-string\fR" 4 +.IP "\fB\-mno\-string\fR" 4 .IX Item "-mno-string" .PD Generate code that uses (does not use) the load string instructions @@ -6046,151 +6748,182 @@ do small block moves. These instructions are generated by default on instructions do not work when the processor is in little endian mode. The exceptions are \s-1PPC740\s0 and \s-1PPC750\s0 which permit the instructions usage in little endian mode. -.Ip "\fB\-mupdate\fR" 4 +.IP "\fB\-mupdate\fR" 4 .IX Item "-mupdate" .PD 0 -.Ip "\fB\-mno-update\fR" 4 +.IP "\fB\-mno\-update\fR" 4 .IX Item "-mno-update" .PD Generate code that uses (does not use) the load or store instructions that update the base register to the address of the calculated memory location. These instructions are generated by default. If you use -\&\fB\-mno-update\fR, there is a small window between the time that the +\&\fB\-mno\-update\fR, there is a small window between the time that the stack pointer is updated and the address of the previous frame is stored, which means code that walks the stack frame across interrupts or signals may get corrupted data. -.Ip "\fB\-mfused-madd\fR" 4 +.IP "\fB\-mfused\-madd\fR" 4 .IX Item "-mfused-madd" .PD 0 -.Ip "\fB\-mno-fused-madd\fR" 4 +.IP "\fB\-mno\-fused\-madd\fR" 4 .IX Item "-mno-fused-madd" .PD Generate code that uses (does not use) the floating point multiply and accumulate instructions. These instructions are generated by default if hardware floating is used. -.Ip "\fB\-mno-bit-align\fR" 4 +.IP "\fB\-mno\-bit\-align\fR" 4 .IX Item "-mno-bit-align" .PD 0 -.Ip "\fB\-mbit-align\fR" 4 +.IP "\fB\-mbit\-align\fR" 4 .IX Item "-mbit-align" .PD On System V.4 and embedded PowerPC systems do not (do) force structures and unions that contain bit-fields to be aligned to the base type of the -bit-field. +bit\-field. .Sp For example, by default a structure containing nothing but 8 \&\f(CW\*(C`unsigned\*(C'\fR bit-fields of length 1 would be aligned to a 4 byte -boundary and have a size of 4 bytes. By using \fB\-mno-bit-align\fR, +boundary and have a size of 4 bytes. By using \fB\-mno\-bit\-align\fR, the structure would be aligned to a 1 byte boundary and be one byte in size. -.Ip "\fB\-mno-strict-align\fR" 4 +.IP "\fB\-mno\-strict\-align\fR" 4 .IX Item "-mno-strict-align" .PD 0 -.Ip "\fB\-mstrict-align\fR" 4 +.IP "\fB\-mstrict\-align\fR" 4 .IX Item "-mstrict-align" .PD On System V.4 and embedded PowerPC systems do not (do) assume that unaligned memory references will be handled by the system. -.Ip "\fB\-mrelocatable\fR" 4 +.IP "\fB\-mrelocatable\fR" 4 .IX Item "-mrelocatable" .PD 0 -.Ip "\fB\-mno-relocatable\fR" 4 +.IP "\fB\-mno\-relocatable\fR" 4 .IX Item "-mno-relocatable" .PD On embedded PowerPC systems generate code that allows (does not allow) the program to be relocated to a different address at runtime. If you use \fB\-mrelocatable\fR on any module, all objects linked together must -be compiled with \fB\-mrelocatable\fR or \fB\-mrelocatable-lib\fR. -.Ip "\fB\-mrelocatable-lib\fR" 4 +be compiled with \fB\-mrelocatable\fR or \fB\-mrelocatable\-lib\fR. +.IP "\fB\-mrelocatable\-lib\fR" 4 .IX Item "-mrelocatable-lib" .PD 0 -.Ip "\fB\-mno-relocatable-lib\fR" 4 +.IP "\fB\-mno\-relocatable\-lib\fR" 4 .IX Item "-mno-relocatable-lib" .PD On embedded PowerPC systems generate code that allows (does not allow) the program to be relocated to a different address at runtime. Modules -compiled with \fB\-mrelocatable-lib\fR can be linked with either modules -compiled without \fB\-mrelocatable\fR and \fB\-mrelocatable-lib\fR or +compiled with \fB\-mrelocatable\-lib\fR can be linked with either modules +compiled without \fB\-mrelocatable\fR and \fB\-mrelocatable\-lib\fR or with modules compiled with the \fB\-mrelocatable\fR options. -.Ip "\fB\-mno-toc\fR" 4 +.IP "\fB\-mno\-toc\fR" 4 .IX Item "-mno-toc" .PD 0 -.Ip "\fB\-mtoc\fR" 4 +.IP "\fB\-mtoc\fR" 4 .IX Item "-mtoc" .PD On System V.4 and embedded PowerPC systems do not (do) assume that register 2 contains a pointer to a global area pointing to the addresses used in the program. -.Ip "\fB\-mlittle\fR" 4 +.IP "\fB\-mlittle\fR" 4 .IX Item "-mlittle" .PD 0 -.Ip "\fB\-mlittle-endian\fR" 4 +.IP "\fB\-mlittle\-endian\fR" 4 .IX Item "-mlittle-endian" .PD On System V.4 and embedded PowerPC systems compile code for the -processor in little endian mode. The \fB\-mlittle-endian\fR option is +processor in little endian mode. The \fB\-mlittle\-endian\fR option is the same as \fB\-mlittle\fR. -.Ip "\fB\-mbig\fR" 4 +.IP "\fB\-mbig\fR" 4 .IX Item "-mbig" .PD 0 -.Ip "\fB\-mbig-endian\fR" 4 +.IP "\fB\-mbig\-endian\fR" 4 .IX Item "-mbig-endian" .PD On System V.4 and embedded PowerPC systems compile code for the -processor in big endian mode. The \fB\-mbig-endian\fR option is +processor in big endian mode. The \fB\-mbig\-endian\fR option is the same as \fB\-mbig\fR. -.Ip "\fB\-mcall-sysv\fR" 4 +.IP "\fB\-mdynamic\-no\-pic\fR" 4 +.IX Item "-mdynamic-no-pic" +On Darwin and Mac \s-1OS\s0 X systems, compile code so that it is not +relocatable, but that its external references are relocatable. The +resulting code is suitable for applications, but not shared +libraries. +.IP "\fB\-mprioritize\-restricted\-insns=\fR\fIpriority\fR" 4 +.IX Item "-mprioritize-restricted-insns=priority" +This option controls the priority that is assigned to +dispatch-slot restricted instructions during the second scheduling +pass. The argument \fIpriority\fR takes the value \fI0/1/2\fR to assign +\&\fIno/highest/second\-highest\fR priority to dispatch slot restricted +instructions. +.IP "\fB\-msched\-costly\-dep=\fR\fIdependence_type\fR" 4 +.IX Item "-msched-costly-dep=dependence_type" +This option controls which dependences are considered costly +by the target during instruction scheduling. The argument +\&\fIdependence_type\fR takes one of the following values: +\&\fIno\fR: no dependence is costly, +\&\fIall\fR: all dependences are costly, +\&\fItrue_store_to_load\fR: a true dependence from store to load is costly, +\&\fIstore_to_load\fR: any dependence from store to load is costly, +\&\fInumber\fR: any dependence which latency >= \fInumber\fR is costly. +.IP "\fB\-minsert\-sched\-nops=\fR\fIscheme\fR" 4 +.IX Item "-minsert-sched-nops=scheme" +This option controls which nop insertion scheme will be used during +the second scheduling pass. The argument \fIscheme\fR takes one of the +following values: +\&\fIno\fR: Don't insert nops. +\&\fIpad\fR: Pad with nops any dispatch group which has vacant issue slots, +according to the scheduler's grouping. +\&\fIregroup_exact\fR: Insert nops to force costly dependent insns into +separate groups. Insert exactly as many nops as needed to force an insn +to a new group, according to the estimated processor grouping. +\&\fInumber\fR: Insert nops to force costly dependent insns into +separate groups. Insert \fInumber\fR nops to force an insn to a new group. +.IP "\fB\-mcall\-sysv\fR" 4 .IX Item "-mcall-sysv" On System V.4 and embedded PowerPC systems compile code using calling conventions that adheres to the March 1995 draft of the System V Application Binary Interface, PowerPC processor supplement. This is the -default unless you configured \s-1GCC\s0 using \fBpowerpc-*\-eabiaix\fR. -.Ip "\fB\-mcall-sysv-eabi\fR" 4 +default unless you configured \s-1GCC\s0 using \fBpowerpc\-*\-eabiaix\fR. +.IP "\fB\-mcall\-sysv\-eabi\fR" 4 .IX Item "-mcall-sysv-eabi" -Specify both \fB\-mcall-sysv\fR and \fB\-meabi\fR options. -.Ip "\fB\-mcall-sysv-noeabi\fR" 4 +Specify both \fB\-mcall\-sysv\fR and \fB\-meabi\fR options. +.IP "\fB\-mcall\-sysv\-noeabi\fR" 4 .IX Item "-mcall-sysv-noeabi" -Specify both \fB\-mcall-sysv\fR and \fB\-mno-eabi\fR options. -.Ip "\fB\-mcall-aix\fR" 4 -.IX Item "-mcall-aix" -On System V.4 and embedded PowerPC systems compile code using calling -conventions that are similar to those used on \s-1AIX\s0. This is the -default if you configured \s-1GCC\s0 using \fBpowerpc-*\-eabiaix\fR. -.Ip "\fB\-mcall-solaris\fR" 4 +Specify both \fB\-mcall\-sysv\fR and \fB\-mno\-eabi\fR options. +.IP "\fB\-mcall\-solaris\fR" 4 .IX Item "-mcall-solaris" On System V.4 and embedded PowerPC systems compile code for the Solaris operating system. -.Ip "\fB\-mcall-linux\fR" 4 +.IP "\fB\-mcall\-linux\fR" 4 .IX Item "-mcall-linux" On System V.4 and embedded PowerPC systems compile code for the Linux-based \s-1GNU\s0 system. -.Ip "\fB\-mcall-gnu\fR" 4 +.IP "\fB\-mcall\-gnu\fR" 4 .IX Item "-mcall-gnu" On System V.4 and embedded PowerPC systems compile code for the Hurd-based \s-1GNU\s0 system. -.Ip "\fB\-mcall-netbsd\fR" 4 +.IP "\fB\-mcall\-netbsd\fR" 4 .IX Item "-mcall-netbsd" On System V.4 and embedded PowerPC systems compile code for the NetBSD operating system. -.Ip "\fB\-maix-struct-return\fR" 4 +.IP "\fB\-maix\-struct\-return\fR" 4 .IX Item "-maix-struct-return" Return all structures in memory (as specified by the \s-1AIX\s0 \s-1ABI\s0). -.Ip "\fB\-msvr4\-struct-return\fR" 4 +.IP "\fB\-msvr4\-struct\-return\fR" 4 .IX Item "-msvr4-struct-return" Return structures smaller than 8 bytes in registers (as specified by the \&\s-1SVR4\s0 \s-1ABI\s0). -.Ip "\fB\-mabi=altivec\fR" 4 +.IP "\fB\-mabi=altivec\fR" 4 .IX Item "-mabi=altivec" Extend the current \s-1ABI\s0 with AltiVec \s-1ABI\s0 extensions. This does not change the default \s-1ABI\s0, instead it adds the AltiVec \s-1ABI\s0 extensions to the current \s-1ABI\s0. -.Ip "\fB\-mabi=no-altivec\fR" 4 +.IP "\fB\-mabi=no\-altivec\fR" 4 .IX Item "-mabi=no-altivec" Disable AltiVec \s-1ABI\s0 extensions for the current \s-1ABI\s0. -.Ip "\fB\-mprototype\fR" 4 +.IP "\fB\-mprototype\fR" 4 .IX Item "-mprototype" .PD 0 -.Ip "\fB\-mno-prototype\fR" 4 +.IP "\fB\-mno\-prototype\fR" 4 .IX Item "-mno-prototype" .PD On System V.4 and embedded PowerPC systems assume that all calls to @@ -6201,39 +6934,42 @@ indicate whether floating point values were passed in the floating point registers in case the function takes a variable arguments. With \&\fB\-mprototype\fR, only calls to prototyped variable argument functions will set or clear the bit. -.Ip "\fB\-msim\fR" 4 +.IP "\fB\-msim\fR" 4 .IX Item "-msim" On embedded PowerPC systems, assume that the startup module is called -\&\fIsim-crt0.o\fR and that the standard C libraries are \fIlibsim.a\fR and -\&\fIlibc.a\fR. This is the default for \fBpowerpc-*\-eabisim\fR. +\&\fIsim\-crt0.o\fR and that the standard C libraries are \fIlibsim.a\fR and +\&\fIlibc.a\fR. This is the default for \fBpowerpc\-*\-eabisim\fR. configurations. -.Ip "\fB\-mmvme\fR" 4 +.IP "\fB\-mmvme\fR" 4 .IX Item "-mmvme" On embedded PowerPC systems, assume that the startup module is called \&\fIcrt0.o\fR and the standard C libraries are \fIlibmvme.a\fR and \&\fIlibc.a\fR. -.Ip "\fB\-mads\fR" 4 +.IP "\fB\-mads\fR" 4 .IX Item "-mads" On embedded PowerPC systems, assume that the startup module is called \&\fIcrt0.o\fR and the standard C libraries are \fIlibads.a\fR and \&\fIlibc.a\fR. -.Ip "\fB\-myellowknife\fR" 4 +.IP "\fB\-myellowknife\fR" 4 .IX Item "-myellowknife" On embedded PowerPC systems, assume that the startup module is called \&\fIcrt0.o\fR and the standard C libraries are \fIlibyk.a\fR and \&\fIlibc.a\fR. -.Ip "\fB\-mvxworks\fR" 4 +.IP "\fB\-mvxworks\fR" 4 .IX Item "-mvxworks" On System V.4 and embedded PowerPC systems, specify that you are compiling for a VxWorks system. -.Ip "\fB\-memb\fR" 4 +.IP "\fB\-mwindiss\fR" 4 +.IX Item "-mwindiss" +Specify that you are compiling for the WindISS simulation environment. +.IP "\fB\-memb\fR" 4 .IX Item "-memb" On embedded PowerPC systems, set the \fI\s-1PPC_EMB\s0\fR bit in the \s-1ELF\s0 flags header to indicate that \fBeabi\fR extended relocations are used. -.Ip "\fB\-meabi\fR" 4 +.IP "\fB\-meabi\fR" 4 .IX Item "-meabi" .PD 0 -.Ip "\fB\-mno-eabi\fR" 4 +.IP "\fB\-mno\-eabi\fR" 4 .IX Item "-mno-eabi" .PD On System V.4 and embedded PowerPC systems do (do not) adhere to the @@ -6243,23 +6979,23 @@ means that the stack is aligned to an 8 byte boundary, a function \&\f(CW\*(C`_\|_eabi\*(C'\fR is called to from \f(CW\*(C`main\*(C'\fR to set up the eabi environment, and the \fB\-msdata\fR option can use both \f(CW\*(C`r2\*(C'\fR and \&\f(CW\*(C`r13\*(C'\fR to point to two separate small data areas. Selecting -\&\fB\-mno-eabi\fR means that the stack is aligned to a 16 byte boundary, +\&\fB\-mno\-eabi\fR means that the stack is aligned to a 16 byte boundary, do not call an initialization function from \f(CW\*(C`main\*(C'\fR, and the \&\fB\-msdata\fR option will only use \f(CW\*(C`r13\*(C'\fR to point to a single small data area. The \fB\-meabi\fR option is on by default if you configured \s-1GCC\s0 using one of the \fBpowerpc*\-*\-eabi*\fR options. -.Ip "\fB\-msdata=eabi\fR" 4 +.IP "\fB\-msdata=eabi\fR" 4 .IX Item "-msdata=eabi" On System V.4 and embedded PowerPC systems, put small initialized \&\f(CW\*(C`const\*(C'\fR global and static data in the \fB.sdata2\fR section, which is pointed to by register \f(CW\*(C`r2\*(C'\fR. Put small initialized -non-\f(CW\*(C`const\*(C'\fR global and static data in the \fB.sdata\fR section, +non\-\f(CW\*(C`const\*(C'\fR global and static data in the \fB.sdata\fR section, which is pointed to by register \f(CW\*(C`r13\*(C'\fR. Put small uninitialized global and static data in the \fB.sbss\fR section, which is adjacent to the \fB.sdata\fR section. The \fB\-msdata=eabi\fR option is incompatible with the \fB\-mrelocatable\fR option. The \&\fB\-msdata=eabi\fR option also sets the \fB\-memb\fR option. -.Ip "\fB\-msdata=sysv\fR" 4 +.IP "\fB\-msdata=sysv\fR" 4 .IX Item "-msdata=sysv" On System V.4 and embedded PowerPC systems, put small global and static data in the \fB.sdata\fR section, which is pointed to by register @@ -6267,424 +7003,560 @@ data in the \fB.sdata\fR section, which is pointed to by register \&\fB.sbss\fR section, which is adjacent to the \fB.sdata\fR section. The \fB\-msdata=sysv\fR option is incompatible with the \&\fB\-mrelocatable\fR option. -.Ip "\fB\-msdata=default\fR" 4 +.IP "\fB\-msdata=default\fR" 4 .IX Item "-msdata=default" .PD 0 -.Ip "\fB\-msdata\fR" 4 +.IP "\fB\-msdata\fR" 4 .IX Item "-msdata" .PD On System V.4 and embedded PowerPC systems, if \fB\-meabi\fR is used, compile code the same as \fB\-msdata=eabi\fR, otherwise compile code the same as \fB\-msdata=sysv\fR. -.Ip "\fB\-msdata-data\fR" 4 +.IP "\fB\-msdata\-data\fR" 4 .IX Item "-msdata-data" On System V.4 and embedded PowerPC systems, put small global and static data in the \fB.sdata\fR section. Put small uninitialized global and static data in the \fB.sbss\fR section. Do not use register \f(CW\*(C`r13\*(C'\fR to address small data however. This is the default behavior unless other \fB\-msdata\fR options are used. -.Ip "\fB\-msdata=none\fR" 4 +.IP "\fB\-msdata=none\fR" 4 .IX Item "-msdata=none" .PD 0 -.Ip "\fB\-mno-sdata\fR" 4 +.IP "\fB\-mno\-sdata\fR" 4 .IX Item "-mno-sdata" .PD On embedded PowerPC systems, put all initialized global and static data in the \fB.data\fR section, and all uninitialized data in the \&\fB.bss\fR section. -.Ip "\fB\-G\fR \fInum\fR" 4 +.IP "\fB\-G\fR \fInum\fR" 4 .IX Item "-G num" On embedded PowerPC systems, put global and static items less than or equal to \fInum\fR bytes into the small data or bss sections instead of the normal data or bss section. By default, \fInum\fR is 8. The \&\fB\-G\fR \fInum\fR switch is also passed to the linker. All modules should be compiled with the same \fB\-G\fR \fInum\fR value. -.Ip "\fB\-mregnames\fR" 4 +.IP "\fB\-mregnames\fR" 4 .IX Item "-mregnames" .PD 0 -.Ip "\fB\-mno-regnames\fR" 4 +.IP "\fB\-mno\-regnames\fR" 4 .IX Item "-mno-regnames" .PD On System V.4 and embedded PowerPC systems do (do not) emit register names in the assembly language output using symbolic forms. -.Ip "\fB\-pthread\fR" 4 +.IP "\fB\-mlongcall\fR" 4 +.IX Item "-mlongcall" +.PD 0 +.IP "\fB\-mno\-longcall\fR" 4 +.IX Item "-mno-longcall" +.PD +Default to making all function calls via pointers, so that functions +which reside further than 64 megabytes (67,108,864 bytes) from the +current location can be called. This setting can be overridden by the +\&\f(CW\*(C`shortcall\*(C'\fR function attribute, or by \f(CW\*(C`#pragma longcall(0)\*(C'\fR. +.Sp +Some linkers are capable of detecting out-of-range calls and generating +glue code on the fly. On these systems, long calls are unnecessary and +generate slower code. As of this writing, the \s-1AIX\s0 linker can do this, +as can the \s-1GNU\s0 linker for PowerPC/64. It is planned to add this feature +to the \s-1GNU\s0 linker for 32\-bit PowerPC systems as well. +.Sp +On Mach-O (Darwin) systems, this option directs the compiler emit to +the glue for every direct call, and the Darwin linker decides whether +to use or discard it. +.Sp +In the future, we may cause \s-1GCC\s0 to ignore all longcall specifications +when the linker is known to generate glue. +.IP "\fB\-pthread\fR" 4 .IX Item "-pthread" Adds support for multithreading with the \fIpthreads\fR library. This option sets flags for both the preprocessor and linker. .PP -.I "\s-1IBM\s0 \s-1RT\s0 Options" -.IX Subsection "IBM RT Options" +\fIDarwin Options\fR +.IX Subsection "Darwin Options" .PP -These \fB\-m\fR options are defined for the \s-1IBM\s0 \s-1RT\s0 \s-1PC:\s0 -.Ip "\fB\-min-line-mul\fR" 4 -.IX Item "-min-line-mul" -Use an in-line code sequence for integer multiplies. This is the -default. -.Ip "\fB\-mcall-lib-mul\fR" 4 -.IX Item "-mcall-lib-mul" -Call \f(CW\*(C`lmul$$\*(C'\fR for integer multiples. -.Ip "\fB\-mfull-fp-blocks\fR" 4 -.IX Item "-mfull-fp-blocks" -Generate full-size floating point data blocks, including the minimum -amount of scratch space recommended by \s-1IBM\s0. This is the default. -.Ip "\fB\-mminimum-fp-blocks\fR" 4 -.IX Item "-mminimum-fp-blocks" -Do not include extra scratch space in floating point data blocks. This -results in smaller code, but slower execution, since scratch space must -be allocated dynamically. -.Ip "\fB\-mfp-arg-in-fpregs\fR" 4 -.IX Item "-mfp-arg-in-fpregs" -Use a calling sequence incompatible with the \s-1IBM\s0 calling convention in -which floating point arguments are passed in floating point registers. -Note that \f(CW\*(C`varargs.h\*(C'\fR and \f(CW\*(C`stdarg.h\*(C'\fR will not work with -floating point operands if this option is specified. -.Ip "\fB\-mfp-arg-in-gregs\fR" 4 -.IX Item "-mfp-arg-in-gregs" -Use the normal calling convention for floating point arguments. This is -the default. -.Ip "\fB\-mhc-struct-return\fR" 4 -.IX Item "-mhc-struct-return" -Return structures of more than one word in memory, rather than in a -register. This provides compatibility with the MetaWare HighC (hc) -compiler. Use the option \fB\-fpcc-struct-return\fR for compatibility -with the Portable C Compiler (pcc). -.Ip "\fB\-mnohc-struct-return\fR" 4 -.IX Item "-mnohc-struct-return" -Return some structures of more than one word in registers, when -convenient. This is the default. For compatibility with the -IBM-supplied compilers, use the option \fB\-fpcc-struct-return\fR or the -option \fB\-mhc-struct-return\fR. +These options are defined for all architectures running the Darwin operating +system. They are useful for compatibility with other Mac \s-1OS\s0 compilers. +.IP "\fB\-all_load\fR" 4 +.IX Item "-all_load" +Loads all members of static archive libraries. +See man \fIld\fR\|(1) for more information. +.IP "\fB\-arch_errors_fatal\fR" 4 +.IX Item "-arch_errors_fatal" +Cause the errors having to do with files that have the wrong architecture +to be fatal. +.IP "\fB\-bind_at_load\fR" 4 +.IX Item "-bind_at_load" +Causes the output file to be marked such that the dynamic linker will +bind all undefined references when the file is loaded or launched. +.IP "\fB\-bundle\fR" 4 +.IX Item "-bundle" +Produce a Mach-o bundle format file. +See man \fIld\fR\|(1) for more information. +.IP "\fB\-bundle_loader\fR \fIexecutable\fR" 4 +.IX Item "-bundle_loader executable" +This specifies the \fIexecutable\fR that will be loading the build +output file being linked. See man \fIld\fR\|(1) for more information. +.IP "\fB\-allowable_client\fR \fIclient_name\fR" 4 +.IX Item "-allowable_client client_name" +.PD 0 +.IP "\fB\-arch_only\fR" 4 +.IX Item "-arch_only" +.IP "\fB\-client_name\fR" 4 +.IX Item "-client_name" +.IP "\fB\-compatibility_version\fR" 4 +.IX Item "-compatibility_version" +.IP "\fB\-current_version\fR" 4 +.IX Item "-current_version" +.IP "\fB\-dependency\-file\fR" 4 +.IX Item "-dependency-file" +.IP "\fB\-dylib_file\fR" 4 +.IX Item "-dylib_file" +.IP "\fB\-dylinker_install_name\fR" 4 +.IX Item "-dylinker_install_name" +.IP "\fB\-dynamic\fR" 4 +.IX Item "-dynamic" +.IP "\fB\-dynamiclib\fR" 4 +.IX Item "-dynamiclib" +.IP "\fB\-exported_symbols_list\fR" 4 +.IX Item "-exported_symbols_list" +.IP "\fB\-filelist\fR" 4 +.IX Item "-filelist" +.IP "\fB\-flat_namespace\fR" 4 +.IX Item "-flat_namespace" +.IP "\fB\-force_cpusubtype_ALL\fR" 4 +.IX Item "-force_cpusubtype_ALL" +.IP "\fB\-force_flat_namespace\fR" 4 +.IX Item "-force_flat_namespace" +.IP "\fB\-headerpad_max_install_names\fR" 4 +.IX Item "-headerpad_max_install_names" +.IP "\fB\-image_base\fR" 4 +.IX Item "-image_base" +.IP "\fB\-init\fR" 4 +.IX Item "-init" +.IP "\fB\-install_name\fR" 4 +.IX Item "-install_name" +.IP "\fB\-keep_private_externs\fR" 4 +.IX Item "-keep_private_externs" +.IP "\fB\-multi_module\fR" 4 +.IX Item "-multi_module" +.IP "\fB\-multiply_defined\fR" 4 +.IX Item "-multiply_defined" +.IP "\fB\-multiply_defined_unused\fR" 4 +.IX Item "-multiply_defined_unused" +.IP "\fB\-noall_load\fR" 4 +.IX Item "-noall_load" +.IP "\fB\-nofixprebinding\fR" 4 +.IX Item "-nofixprebinding" +.IP "\fB\-nomultidefs\fR" 4 +.IX Item "-nomultidefs" +.IP "\fB\-noprebind\fR" 4 +.IX Item "-noprebind" +.IP "\fB\-noseglinkedit\fR" 4 +.IX Item "-noseglinkedit" +.IP "\fB\-pagezero_size\fR" 4 +.IX Item "-pagezero_size" +.IP "\fB\-prebind\fR" 4 +.IX Item "-prebind" +.IP "\fB\-prebind_all_twolevel_modules\fR" 4 +.IX Item "-prebind_all_twolevel_modules" +.IP "\fB\-private_bundle\fR" 4 +.IX Item "-private_bundle" +.IP "\fB\-read_only_relocs\fR" 4 +.IX Item "-read_only_relocs" +.IP "\fB\-sectalign\fR" 4 +.IX Item "-sectalign" +.IP "\fB\-sectobjectsymbols\fR" 4 +.IX Item "-sectobjectsymbols" +.IP "\fB\-whyload\fR" 4 +.IX Item "-whyload" +.IP "\fB\-seg1addr\fR" 4 +.IX Item "-seg1addr" +.IP "\fB\-sectcreate\fR" 4 +.IX Item "-sectcreate" +.IP "\fB\-sectobjectsymbols\fR" 4 +.IX Item "-sectobjectsymbols" +.IP "\fB\-sectorder\fR" 4 +.IX Item "-sectorder" +.IP "\fB\-seg_addr_table\fR" 4 +.IX Item "-seg_addr_table" +.IP "\fB\-seg_addr_table_filename\fR" 4 +.IX Item "-seg_addr_table_filename" +.IP "\fB\-seglinkedit\fR" 4 +.IX Item "-seglinkedit" +.IP "\fB\-segprot\fR" 4 +.IX Item "-segprot" +.IP "\fB\-segs_read_only_addr\fR" 4 +.IX Item "-segs_read_only_addr" +.IP "\fB\-segs_read_write_addr\fR" 4 +.IX Item "-segs_read_write_addr" +.IP "\fB\-single_module\fR" 4 +.IX Item "-single_module" +.IP "\fB\-static\fR" 4 +.IX Item "-static" +.IP "\fB\-sub_library\fR" 4 +.IX Item "-sub_library" +.IP "\fB\-sub_umbrella\fR" 4 +.IX Item "-sub_umbrella" +.IP "\fB\-twolevel_namespace\fR" 4 +.IX Item "-twolevel_namespace" +.IP "\fB\-umbrella\fR" 4 +.IX Item "-umbrella" +.IP "\fB\-undefined\fR" 4 +.IX Item "-undefined" +.IP "\fB\-unexported_symbols_list\fR" 4 +.IX Item "-unexported_symbols_list" +.IP "\fB\-weak_reference_mismatches\fR" 4 +.IX Item "-weak_reference_mismatches" +.IP "\fB\-whatsloaded\fR" 4 +.IX Item "-whatsloaded" +.PD +These options are available for Darwin linker. Darwin linker man page +describes them in detail. .PP -.I "\s-1MIPS\s0 Options" +\fI\s-1MIPS\s0 Options\fR .IX Subsection "MIPS Options" -.PP -These \fB\-m\fR options are defined for the \s-1MIPS\s0 family of computers: -.Ip "\fB\-march=\fR\fIcpu-type\fR" 4 -.IX Item "-march=cpu-type" -Assume the defaults for the machine type \fIcpu-type\fR when generating -instructions. The choices for \fIcpu-type\fR are \fBr2000\fR, \fBr3000\fR, -\&\fBr3900\fR, \fBr4000\fR, \fBr4100\fR, \fBr4300\fR, \fBr4400\fR, -\&\fBr4600\fR, \fBr4650\fR, \fBr5000\fR, \fBr6000\fR, \fBr8000\fR, -and \fBorion\fR. Additionally, the \fBr2000\fR, \fBr3000\fR, -\&\fBr4000\fR, \fBr5000\fR, and \fBr6000\fR can be abbreviated as -\&\fBr2k\fR (or \fBr2K\fR), \fBr3k\fR, etc. -.Ip "\fB\-mtune=\fR\fIcpu-type\fR" 4 -.IX Item "-mtune=cpu-type" -Assume the defaults for the machine type \fIcpu-type\fR when scheduling -instructions. The choices for \fIcpu-type\fR are \fBr2000\fR, \fBr3000\fR, -\&\fBr3900\fR, \fBr4000\fR, \fBr4100\fR, \fBr4300\fR, \fBr4400\fR, -\&\fBr4600\fR, \fBr4650\fR, \fBr5000\fR, \fBr6000\fR, \fBr8000\fR, -and \fBorion\fR. Additionally, the \fBr2000\fR, \fBr3000\fR, -\&\fBr4000\fR, \fBr5000\fR, and \fBr6000\fR can be abbreviated as -\&\fBr2k\fR (or \fBr2K\fR), \fBr3k\fR, etc. While picking a specific -\&\fIcpu-type\fR will schedule things appropriately for that particular -chip, the compiler will not generate any code that does not meet level 1 -of the \s-1MIPS\s0 \s-1ISA\s0 (instruction set architecture) without a \fB\-mipsX\fR -or \fB\-mabi\fR switch being used. -.Ip "\fB\-mcpu=\fR\fIcpu-type\fR" 4 -.IX Item "-mcpu=cpu-type" -This is identical to specifying both \fB\-march\fR and \fB\-mtune\fR. -.Ip "\fB\-mips1\fR" 4 +.IP "\fB\-EB\fR" 4 +.IX Item "-EB" +Generate big-endian code. +.IP "\fB\-EL\fR" 4 +.IX Item "-EL" +Generate little-endian code. This is the default for \fBmips*el\-*\-*\fR +configurations. +.IP "\fB\-march=\fR\fIarch\fR" 4 +.IX Item "-march=arch" +Generate code that will run on \fIarch\fR, which can be the name of a +generic \s-1MIPS\s0 \s-1ISA\s0, or the name of a particular processor. +The \s-1ISA\s0 names are: +\&\fBmips1\fR, \fBmips2\fR, \fBmips3\fR, \fBmips4\fR, +\&\fBmips32\fR, \fBmips32r2\fR, and \fBmips64\fR. +The processor names are: +\&\fB4kc\fR, \fB4kp\fR, \fB5kc\fR, \fB20kc\fR, +\&\fBm4k\fR, +\&\fBr2000\fR, \fBr3000\fR, \fBr3900\fR, \fBr4000\fR, \fBr4400\fR, +\&\fBr4600\fR, \fBr4650\fR, \fBr6000\fR, \fBr8000\fR, \fBrm7000\fR, +\&\fBrm9000\fR, +\&\fBorion\fR, +\&\fBsb1\fR, +\&\fBvr4100\fR, \fBvr4111\fR, \fBvr4120\fR, \fBvr4300\fR, +\&\fBvr5000\fR, \fBvr5400\fR and \fBvr5500\fR. +The special value \fBfrom-abi\fR selects the +most compatible architecture for the selected \s-1ABI\s0 (that is, +\&\fBmips1\fR for 32\-bit ABIs and \fBmips3\fR for 64\-bit ABIs). +.Sp +In processor names, a final \fB000\fR can be abbreviated as \fBk\fR +(for example, \fB\-march=r2k\fR). Prefixes are optional, and +\&\fBvr\fR may be written \fBr\fR. +.Sp +\&\s-1GCC\s0 defines two macros based on the value of this option. The first +is \fB_MIPS_ARCH\fR, which gives the name of target architecture, as +a string. The second has the form \fB_MIPS_ARCH_\fR\fIfoo\fR, +where \fIfoo\fR is the capitalized value of \fB_MIPS_ARCH\fR. +For example, \fB\-march=r2000\fR will set \fB_MIPS_ARCH\fR +to \fB\*(L"r2000\*(R"\fR and define the macro \fB_MIPS_ARCH_R2000\fR. +.Sp +Note that the \fB_MIPS_ARCH\fR macro uses the processor names given +above. In other words, it will have the full prefix and will not +abbreviate \fB000\fR as \fBk\fR. In the case of \fBfrom-abi\fR, +the macro names the resolved architecture (either \fB\*(L"mips1\*(R"\fR or +\&\fB\*(L"mips3\*(R"\fR). It names the default architecture when no +\&\fB\-march\fR option is given. +.IP "\fB\-mtune=\fR\fIarch\fR" 4 +.IX Item "-mtune=arch" +Optimize for \fIarch\fR. Among other things, this option controls +the way instructions are scheduled, and the perceived cost of arithmetic +operations. The list of \fIarch\fR values is the same as for +\&\fB\-march\fR. +.Sp +When this option is not used, \s-1GCC\s0 will optimize for the processor +specified by \fB\-march\fR. By using \fB\-march\fR and +\&\fB\-mtune\fR together, it is possible to generate code that will +run on a family of processors, but optimize the code for one +particular member of that family. +.Sp +\&\fB\-mtune\fR defines the macros \fB_MIPS_TUNE\fR and +\&\fB_MIPS_TUNE_\fR\fIfoo\fR, which work in the same way as the +\&\fB\-march\fR ones described above. +.IP "\fB\-mips1\fR" 4 .IX Item "-mips1" -Issue instructions from level 1 of the \s-1MIPS\s0 \s-1ISA\s0. This is the default. -\&\fBr3000\fR is the default \fIcpu-type\fR at this \s-1ISA\s0 level. -.Ip "\fB\-mips2\fR" 4 +Equivalent to \fB\-march=mips1\fR. +.IP "\fB\-mips2\fR" 4 .IX Item "-mips2" -Issue instructions from level 2 of the \s-1MIPS\s0 \s-1ISA\s0 (branch likely, square -root instructions). \fBr6000\fR is the default \fIcpu-type\fR at this -\&\s-1ISA\s0 level. -.Ip "\fB\-mips3\fR" 4 +Equivalent to \fB\-march=mips2\fR. +.IP "\fB\-mips3\fR" 4 .IX Item "-mips3" -Issue instructions from level 3 of the \s-1MIPS\s0 \s-1ISA\s0 (64\-bit instructions). -\&\fBr4000\fR is the default \fIcpu-type\fR at this \s-1ISA\s0 level. -.Ip "\fB\-mips4\fR" 4 +Equivalent to \fB\-march=mips3\fR. +.IP "\fB\-mips4\fR" 4 .IX Item "-mips4" -Issue instructions from level 4 of the \s-1MIPS\s0 \s-1ISA\s0 (conditional move, -prefetch, enhanced \s-1FPU\s0 instructions). \fBr8000\fR is the default -\&\fIcpu-type\fR at this \s-1ISA\s0 level. -.Ip "\fB\-mfp32\fR" 4 -.IX Item "-mfp32" -Assume that 32 32\-bit floating point registers are available. This is -the default. -.Ip "\fB\-mfp64\fR" 4 -.IX Item "-mfp64" -Assume that 32 64\-bit floating point registers are available. This is -the default when the \fB\-mips3\fR option is used. -.Ip "\fB\-mfused-madd\fR" 4 -.IX Item "-mfused-madd" +Equivalent to \fB\-march=mips4\fR. +.IP "\fB\-mips32\fR" 4 +.IX Item "-mips32" +Equivalent to \fB\-march=mips32\fR. +.IP "\fB\-mips32r2\fR" 4 +.IX Item "-mips32r2" +Equivalent to \fB\-march=mips32r2\fR. +.IP "\fB\-mips64\fR" 4 +.IX Item "-mips64" +Equivalent to \fB\-march=mips64\fR. +.IP "\fB\-mips16\fR" 4 +.IX Item "-mips16" .PD 0 -.Ip "\fB\-mno-fused-madd\fR" 4 -.IX Item "-mno-fused-madd" +.IP "\fB\-mno\-mips16\fR" 4 +.IX Item "-mno-mips16" .PD -Generate code that uses (does not use) the floating point multiply and -accumulate instructions, when they are available. These instructions -are generated by default if they are available, but this may be -undesirable if the extra precision causes problems or on certain chips -in the mode where denormals are rounded to zero where denormals -generated by multiply and accumulate instructions cause exceptions -anyway. -.Ip "\fB\-mgp32\fR" 4 -.IX Item "-mgp32" -Assume that 32 32\-bit general purpose registers are available. This is -the default. -.Ip "\fB\-mgp64\fR" 4 -.IX Item "-mgp64" -Assume that 32 64\-bit general purpose registers are available. This is -the default when the \fB\-mips3\fR option is used. -.Ip "\fB\-mint64\fR" 4 -.IX Item "-mint64" -Force int and long types to be 64 bits wide. See \fB\-mlong32\fR for an -explanation of the default, and the width of pointers. -.Ip "\fB\-mlong64\fR" 4 -.IX Item "-mlong64" -Force long types to be 64 bits wide. See \fB\-mlong32\fR for an -explanation of the default, and the width of pointers. -.Ip "\fB\-mlong32\fR" 4 -.IX Item "-mlong32" -Force long, int, and pointer types to be 32 bits wide. -.Sp -If none of \fB\-mlong32\fR, \fB\-mlong64\fR, or \fB\-mint64\fR are set, -the size of ints, longs, and pointers depends on the \s-1ABI\s0 and \s-1ISA\s0 chosen. -For \fB\-mabi=32\fR, and \fB\-mabi=n32\fR, ints and longs are 32 bits -wide. For \fB\-mabi=64\fR, ints are 32 bits, and longs are 64 bits wide. -For \fB\-mabi=eabi\fR and either \fB\-mips1\fR or \fB\-mips2\fR, ints -and longs are 32 bits wide. For \fB\-mabi=eabi\fR and higher ISAs, ints -are 32 bits, and longs are 64 bits wide. The width of pointer types is -the smaller of the width of longs or the width of general purpose -registers (which in turn depends on the \s-1ISA\s0). -.Ip "\fB\-mabi=32\fR" 4 +Use (do not use) the \s-1MIPS16\s0 \s-1ISA\s0. +.IP "\fB\-mabi=32\fR" 4 .IX Item "-mabi=32" .PD 0 -.Ip "\fB\-mabi=o64\fR" 4 +.IP "\fB\-mabi=o64\fR" 4 .IX Item "-mabi=o64" -.Ip "\fB\-mabi=n32\fR" 4 +.IP "\fB\-mabi=n32\fR" 4 .IX Item "-mabi=n32" -.Ip "\fB\-mabi=64\fR" 4 +.IP "\fB\-mabi=64\fR" 4 .IX Item "-mabi=64" -.Ip "\fB\-mabi=eabi\fR" 4 +.IP "\fB\-mabi=eabi\fR" 4 .IX Item "-mabi=eabi" .PD -Generate code for the indicated \s-1ABI\s0. The default instruction level is -\&\fB\-mips1\fR for \fB32\fR, \fB\-mips3\fR for \fBn32\fR, and -\&\fB\-mips4\fR otherwise. Conversely, with \fB\-mips1\fR or -\&\fB\-mips2\fR, the default \s-1ABI\s0 is \fB32\fR; otherwise, the default \s-1ABI\s0 -is \fB64\fR. -.Ip "\fB\-mmips-as\fR" 4 -.IX Item "-mmips-as" -Generate code for the \s-1MIPS\s0 assembler, and invoke \fImips-tfile\fR to -add normal debug information. This is the default for all -platforms except for the \s-1OSF/1\s0 reference platform, using the OSF/rose -object format. If the either of the \fB\-gstabs\fR or \fB\-gstabs+\fR -switches are used, the \fImips-tfile\fR program will encapsulate the -stabs within \s-1MIPS\s0 \s-1ECOFF\s0. -.Ip "\fB\-mgas\fR" 4 -.IX Item "-mgas" -Generate code for the \s-1GNU\s0 assembler. This is the default on the \s-1OSF/1\s0 -reference platform, using the OSF/rose object format. Also, this is -the default if the configure option \fB\*(--with-gnu-as\fR is used. -.Ip "\fB\-msplit-addresses\fR" 4 -.IX Item "-msplit-addresses" -.PD 0 -.Ip "\fB\-mno-split-addresses\fR" 4 -.IX Item "-mno-split-addresses" -.PD -Generate code to load the high and low parts of address constants separately. -This allows \s-1GCC\s0 to optimize away redundant loads of the high order -bits of addresses. This optimization requires \s-1GNU\s0 as and \s-1GNU\s0 ld. -This optimization is enabled by default for some embedded targets where -\&\s-1GNU\s0 as and \s-1GNU\s0 ld are standard. -.Ip "\fB\-mrnames\fR" 4 -.IX Item "-mrnames" -.PD 0 -.Ip "\fB\-mno-rnames\fR" 4 -.IX Item "-mno-rnames" -.PD -The \fB\-mrnames\fR switch says to output code using the \s-1MIPS\s0 software -names for the registers, instead of the hardware names (ie, \fIa0\fR -instead of \fI$4\fR). The only known assembler that supports this option -is the Algorithmics assembler. -.Ip "\fB\-mgpopt\fR" 4 -.IX Item "-mgpopt" -.PD 0 -.Ip "\fB\-mno-gpopt\fR" 4 -.IX Item "-mno-gpopt" -.PD -The \fB\-mgpopt\fR switch says to write all of the data declarations -before the instructions in the text section, this allows the \s-1MIPS\s0 -assembler to generate one word memory references instead of using two -words for short global or static data items. This is on by default if -optimization is selected. -.Ip "\fB\-mstats\fR" 4 -.IX Item "-mstats" -.PD 0 -.Ip "\fB\-mno-stats\fR" 4 -.IX Item "-mno-stats" -.PD -For each non-inline function processed, the \fB\-mstats\fR switch -causes the compiler to emit one line to the standard error file to -print statistics about the program (number of registers saved, stack -size, etc.). -.Ip "\fB\-mmemcpy\fR" 4 -.IX Item "-mmemcpy" -.PD 0 -.Ip "\fB\-mno-memcpy\fR" 4 -.IX Item "-mno-memcpy" -.PD -The \fB\-mmemcpy\fR switch makes all block moves call the appropriate -string function (\fBmemcpy\fR or \fBbcopy\fR) instead of possibly -generating inline code. -.Ip "\fB\-mmips-tfile\fR" 4 -.IX Item "-mmips-tfile" -.PD 0 -.Ip "\fB\-mno-mips-tfile\fR" 4 -.IX Item "-mno-mips-tfile" -.PD -The \fB\-mno-mips-tfile\fR switch causes the compiler not -postprocess the object file with the \fImips-tfile\fR program, -after the \s-1MIPS\s0 assembler has generated it to add debug support. If -\&\fImips-tfile\fR is not run, then no local variables will be -available to the debugger. In addition, \fIstage2\fR and -\&\fIstage3\fR objects will have the temporary file names passed to the -assembler embedded in the object file, which means the objects will -not compare the same. The \fB\-mno-mips-tfile\fR switch should only -be used when there are bugs in the \fImips-tfile\fR program that -prevents compilation. -.Ip "\fB\-msoft-float\fR" 4 -.IX Item "-msoft-float" -Generate output containing library calls for floating point. -\&\fBWarning:\fR the requisite libraries are not part of \s-1GCC\s0. -Normally the facilities of the machine's usual C compiler are used, but -this can't be done directly in cross-compilation. You must make your -own arrangements to provide suitable library functions for -cross-compilation. -.Ip "\fB\-mhard-float\fR" 4 -.IX Item "-mhard-float" -Generate output containing floating point instructions. This is the -default if you use the unmodified sources. -.Ip "\fB\-mabicalls\fR" 4 +Generate code for the given \s-1ABI\s0. +.Sp +Note that the \s-1EABI\s0 has a 32\-bit and a 64\-bit variant. \s-1GCC\s0 normally +generates 64\-bit code when you select a 64\-bit architecture, but you +can use \fB\-mgp32\fR to get 32\-bit code instead. +.IP "\fB\-mabicalls\fR" 4 .IX Item "-mabicalls" .PD 0 -.Ip "\fB\-mno-abicalls\fR" 4 +.IP "\fB\-mno\-abicalls\fR" 4 .IX Item "-mno-abicalls" .PD -Emit (or do not emit) the pseudo operations \fB.abicalls\fR, -\&\fB.cpload\fR, and \fB.cprestore\fR that some System V.4 ports use for -position independent code. -.Ip "\fB\-mlong-calls\fR" 4 -.IX Item "-mlong-calls" -.PD 0 -.Ip "\fB\-mno-long-calls\fR" 4 -.IX Item "-mno-long-calls" -.PD -Do all calls with the \fB\s-1JALR\s0\fR instruction, which requires -loading up a function's address into a register before the call. -You need to use this switch, if you call outside of the current -512 megabyte segment to functions that are not through pointers. -.Ip "\fB\-mhalf-pic\fR" 4 -.IX Item "-mhalf-pic" +Generate (do not generate) SVR4\-style position-independent code. +\&\fB\-mabicalls\fR is the default for SVR4\-based systems. +.IP "\fB\-mxgot\fR" 4 +.IX Item "-mxgot" .PD 0 -.Ip "\fB\-mno-half-pic\fR" 4 -.IX Item "-mno-half-pic" +.IP "\fB\-mno\-xgot\fR" 4 +.IX Item "-mno-xgot" .PD -Put pointers to extern references into the data section and load them -up, rather than put the references in the text section. -.Ip "\fB\-membedded-pic\fR" 4 +Lift (do not lift) the usual restrictions on the size of the global +offset table. +.Sp +\&\s-1GCC\s0 normally uses a single instruction to load values from the \s-1GOT\s0. +While this is relatively efficient, it will only work if the \s-1GOT\s0 +is smaller than about 64k. Anything larger will cause the linker +to report an error such as: +.Sp +.Vb 1 +\& relocation truncated to fit: R_MIPS_GOT16 foobar +.Ve +.Sp +If this happens, you should recompile your code with \fB\-mxgot\fR. +It should then work with very large GOTs, although it will also be +less efficient, since it will take three instructions to fetch the +value of a global symbol. +.Sp +Note that some linkers can create multiple GOTs. If you have such a +linker, you should only need to use \fB\-mxgot\fR when a single object +file accesses more than 64k's worth of \s-1GOT\s0 entries. Very few do. +.Sp +These options have no effect unless \s-1GCC\s0 is generating position +independent code. +.IP "\fB\-membedded\-pic\fR" 4 .IX Item "-membedded-pic" .PD 0 -.Ip "\fB\-mno-embedded-pic\fR" 4 +.IP "\fB\-mno\-embedded\-pic\fR" 4 .IX Item "-mno-embedded-pic" .PD -Generate \s-1PIC\s0 code suitable for some embedded systems. All calls are -made using \s-1PC\s0 relative address, and all data is addressed using the \f(CW$gp\fR -register. No more than 65536 bytes of global data may be used. This -requires \s-1GNU\s0 as and \s-1GNU\s0 ld which do most of the work. This currently -only works on targets which use \s-1ECOFF\s0; it does not work with \s-1ELF\s0. -.Ip "\fB\-membedded-data\fR" 4 +Generate (do not generate) position-independent code suitable for some +embedded systems. All calls are made using \s-1PC\s0 relative addresses, and +all data is addressed using the \f(CW$gp\fR register. No more than 65536 +bytes of global data may be used. This requires \s-1GNU\s0 as and \s-1GNU\s0 ld, +which do most of the work. +.IP "\fB\-mgp32\fR" 4 +.IX Item "-mgp32" +Assume that general-purpose registers are 32 bits wide. +.IP "\fB\-mgp64\fR" 4 +.IX Item "-mgp64" +Assume that general-purpose registers are 64 bits wide. +.IP "\fB\-mfp32\fR" 4 +.IX Item "-mfp32" +Assume that floating-point registers are 32 bits wide. +.IP "\fB\-mfp64\fR" 4 +.IX Item "-mfp64" +Assume that floating-point registers are 64 bits wide. +.IP "\fB\-mhard\-float\fR" 4 +.IX Item "-mhard-float" +Use floating-point coprocessor instructions. +.IP "\fB\-msoft\-float\fR" 4 +.IX Item "-msoft-float" +Do not use floating-point coprocessor instructions. Implement +floating-point calculations using library calls instead. +.IP "\fB\-msingle\-float\fR" 4 +.IX Item "-msingle-float" +Assume that the floating-point coprocessor only supports single-precision +operations. +.IP "\fB\-mdouble\-float\fR" 4 +.IX Item "-mdouble-float" +Assume that the floating-point coprocessor supports double-precision +operations. This is the default. +.IP "\fB\-mint64\fR" 4 +.IX Item "-mint64" +Force \f(CW\*(C`int\*(C'\fR and \f(CW\*(C`long\*(C'\fR types to be 64 bits wide. See +\&\fB\-mlong32\fR for an explanation of the default and the way +that the pointer size is determined. +.IP "\fB\-mlong64\fR" 4 +.IX Item "-mlong64" +Force \f(CW\*(C`long\*(C'\fR types to be 64 bits wide. See \fB\-mlong32\fR for +an explanation of the default and the way that the pointer size is +determined. +.IP "\fB\-mlong32\fR" 4 +.IX Item "-mlong32" +Force \f(CW\*(C`long\*(C'\fR, \f(CW\*(C`int\*(C'\fR, and pointer types to be 32 bits wide. +.Sp +The default size of \f(CW\*(C`int\*(C'\fRs, \f(CW\*(C`long\*(C'\fRs and pointers depends on +the \s-1ABI\s0. All the supported ABIs use 32\-bit \f(CW\*(C`int\*(C'\fRs. The n64 \s-1ABI\s0 +uses 64\-bit \f(CW\*(C`long\*(C'\fRs, as does the 64\-bit \s-1EABI\s0; the others use +32\-bit \f(CW\*(C`long\*(C'\fRs. Pointers are the same size as \f(CW\*(C`long\*(C'\fRs, +or the same size as integer registers, whichever is smaller. +.IP "\fB\-G\fR \fInum\fR" 4 +.IX Item "-G num" +Put global and static items less than or equal to \fInum\fR bytes into +the small data or bss section instead of the normal data or bss section. +This allows the data to be accessed using a single instruction. +.Sp +All modules should be compiled with the same \fB\-G\fR \fInum\fR +value. +.IP "\fB\-membedded\-data\fR" 4 .IX Item "-membedded-data" .PD 0 -.Ip "\fB\-mno-embedded-data\fR" 4 +.IP "\fB\-mno\-embedded\-data\fR" 4 .IX Item "-mno-embedded-data" .PD Allocate variables to the read-only data section first if possible, then next in the small data section if possible, otherwise in data. This gives slightly slower code than the default, but reduces the amount of \s-1RAM\s0 required when executing, and thus may be preferred for some embedded systems. -.Ip "\fB\-muninit-const-in-rodata\fR" 4 +.IP "\fB\-muninit\-const\-in\-rodata\fR" 4 .IX Item "-muninit-const-in-rodata" .PD 0 -.Ip "\fB\-mno-uninit-const-in-rodata\fR" 4 +.IP "\fB\-mno\-uninit\-const\-in\-rodata\fR" 4 .IX Item "-mno-uninit-const-in-rodata" .PD -When used together with \fB\-membedded-data\fR, it will always store uninitialized -const variables in the read-only data section. -.Ip "\fB\-msingle-float\fR" 4 -.IX Item "-msingle-float" +Put uninitialized \f(CW\*(C`const\*(C'\fR variables in the read-only data section. +This option is only meaningful in conjunction with \fB\-membedded\-data\fR. +.IP "\fB\-msplit\-addresses\fR" 4 +.IX Item "-msplit-addresses" .PD 0 -.Ip "\fB\-mdouble-float\fR" 4 -.IX Item "-mdouble-float" +.IP "\fB\-mno\-split\-addresses\fR" 4 +.IX Item "-mno-split-addresses" +.PD +Enable (disable) use of the \f(CW\*(C`%hi()\*(C'\fR and \f(CW\*(C`%lo()\*(C'\fR assembler +relocation operators. This option has been superceded by +\&\fB\-mexplicit\-relocs\fR but is retained for backwards compatibility. +.IP "\fB\-mexplicit\-relocs\fR" 4 +.IX Item "-mexplicit-relocs" +.PD 0 +.IP "\fB\-mno\-explicit\-relocs\fR" 4 +.IX Item "-mno-explicit-relocs" .PD -The \fB\-msingle-float\fR switch tells gcc to assume that the floating -point coprocessor only supports single precision operations, as on the -\&\fBr4650\fR chip. The \fB\-mdouble-float\fR switch permits gcc to use -double precision operations. This is the default. -.Ip "\fB\-mmad\fR" 4 +Use (do not use) assembler relocation operators when dealing with symbolic +addresses. The alternative, selected by \fB\-mno\-explicit\-relocs\fR, +is to use assembler macros instead. +.Sp +\&\fB\-mexplicit\-relocs\fR is usually the default if \s-1GCC\s0 was +configured to use an assembler that supports relocation operators. +However, there are two exceptions: +.RS 4 +.IP "*" 4 +\&\s-1GCC\s0 is not yet able to generate explicit relocations for the combination +of \fB\-mabi=64\fR and \fB\-mno\-abicalls\fR. This will be addressed +in a future release. +.IP "*" 4 +The combination of \fB\-mabicalls\fR and \fB\-fno\-unit\-at\-a\-time\fR +implies \fB\-mno\-explicit\-relocs\fR unless explicitly overridden. +This is because, when generating abicalls, the choice of relocation +depends on whether a symbol is local or global. In some rare cases, +\&\s-1GCC\s0 will not be able to decide this until the whole compilation unit +has been read. +.RE +.RS 4 +.RE +.IP "\fB\-mrnames\fR" 4 +.IX Item "-mrnames" +.PD 0 +.IP "\fB\-mno\-rnames\fR" 4 +.IX Item "-mno-rnames" +.PD +Generate (do not generate) code that refers to registers using their +software names. The default is \fB\-mno\-rnames\fR, which tells \s-1GCC\s0 +to use hardware names like \fB$4\fR instead of software names like +\&\fBa0\fR. The only assembler known to support \fB\-rnames\fR is +the Algorithmics assembler. +.IP "\fB\-mcheck\-zero\-division\fR" 4 +.IX Item "-mcheck-zero-division" +.PD 0 +.IP "\fB\-mno\-check\-zero\-division\fR" 4 +.IX Item "-mno-check-zero-division" +.PD +Trap (do not trap) on integer division by zero. The default is +\&\fB\-mcheck\-zero\-division\fR. +.IP "\fB\-mmemcpy\fR" 4 +.IX Item "-mmemcpy" +.PD 0 +.IP "\fB\-mno\-memcpy\fR" 4 +.IX Item "-mno-memcpy" +.PD +Force (do not force) the use of \f(CW\*(C`memcpy()\*(C'\fR for non-trivial block +moves. The default is \fB\-mno\-memcpy\fR, which allows \s-1GCC\s0 to inline +most constant-sized copies. +.IP "\fB\-mlong\-calls\fR" 4 +.IX Item "-mlong-calls" +.PD 0 +.IP "\fB\-mno\-long\-calls\fR" 4 +.IX Item "-mno-long-calls" +.PD +Disable (do not disable) use of the \f(CW\*(C`jal\*(C'\fR instruction. Calling +functions using \f(CW\*(C`jal\*(C'\fR is more efficient but requires the caller +and callee to be in the same 256 megabyte segment. +.Sp +This option has no effect on abicalls code. The default is +\&\fB\-mno\-long\-calls\fR. +.IP "\fB\-mmad\fR" 4 .IX Item "-mmad" .PD 0 -.Ip "\fB\-mno-mad\fR" 4 +.IP "\fB\-mno\-mad\fR" 4 .IX Item "-mno-mad" .PD -Permit use of the \fBmad\fR, \fBmadu\fR and \fBmul\fR instructions, -as on the \fBr4650\fR chip. -.Ip "\fB\-m4650\fR" 4 -.IX Item "-m4650" -Turns on \fB\-msingle-float\fR, \fB\-mmad\fR, and, at least for now, -\&\fB\-mcpu=r4650\fR. -.Ip "\fB\-mips16\fR" 4 -.IX Item "-mips16" +Enable (disable) use of the \f(CW\*(C`mad\*(C'\fR, \f(CW\*(C`madu\*(C'\fR and \f(CW\*(C`mul\*(C'\fR +instructions, as provided by the R4650 \s-1ISA\s0. +.IP "\fB\-mfused\-madd\fR" 4 +.IX Item "-mfused-madd" .PD 0 -.Ip "\fB\-mno-mips16\fR" 4 -.IX Item "-mno-mips16" +.IP "\fB\-mno\-fused\-madd\fR" 4 +.IX Item "-mno-fused-madd" .PD -Enable 16\-bit instructions. -.Ip "\fB\-mentry\fR" 4 -.IX Item "-mentry" -Use the entry and exit pseudo ops. This option can only be used with -\&\fB\-mips16\fR. -.Ip "\fB\-EL\fR" 4 -.IX Item "-EL" -Compile code for the processor in little endian mode. -The requisite libraries are assumed to exist. -.Ip "\fB\-EB\fR" 4 -.IX Item "-EB" -Compile code for the processor in big endian mode. -The requisite libraries are assumed to exist. -.Ip "\fB\-G\fR \fInum\fR" 4 -.IX Item "-G num" -Put global and static items less than or equal to \fInum\fR bytes into -the small data or bss sections instead of the normal data or bss -section. This allows the assembler to emit one word memory reference -instructions based on the global pointer (\fIgp\fR or \fI$28\fR), -instead of the normal two words used. By default, \fInum\fR is 8 when -the \s-1MIPS\s0 assembler is used, and 0 when the \s-1GNU\s0 assembler is used. The -\&\fB\-G\fR \fInum\fR switch is also passed to the assembler and linker. -All modules should be compiled with the same \fB\-G\fR \fInum\fR -value. -.Ip "\fB\-nocpp\fR" 4 +Enable (disable) use of the floating point multiply-accumulate +instructions, when they are available. The default is +\&\fB\-mfused\-madd\fR. +.Sp +When multiply-accumulate instructions are used, the intermediate +product is calculated to infinite precision and is not subject to +the \s-1FCSR\s0 Flush to Zero bit. This may be undesirable in some +circumstances. +.IP "\fB\-nocpp\fR" 4 .IX Item "-nocpp" Tell the \s-1MIPS\s0 assembler to not run its preprocessor over user assembler files (with a \fB.s\fR suffix) when assembling them. -.Ip "\fB\-mfix7000\fR" 4 -.IX Item "-mfix7000" -Pass an option to gas which will cause nops to be inserted if -the read of the destination register of an mfhi or mflo instruction -occurs in the following two instructions. -.Ip "\fB\-no-crt0\fR" 4 -.IX Item "-no-crt0" -Do not include the default crt0. -.Ip "\fB\-mflush-func=\fR\fIfunc\fR" 4 +.IP "\fB\-mfix\-sb1\fR" 4 +.IX Item "-mfix-sb1" +.PD 0 +.IP "\fB\-mno\-fix\-sb1\fR" 4 +.IX Item "-mno-fix-sb1" +.PD +Work around certain \s-1SB\-1\s0 \s-1CPU\s0 core errata. +(This flag currently works around the \s-1SB\-1\s0 revision 2 +``F1'' and ``F2'' floating point errata.) +.IP "\fB\-mflush\-func=\fR\fIfunc\fR" 4 .IX Item "-mflush-func=func" .PD 0 -.Ip "\fB\-mno-flush-func\fR" 4 +.IP "\fB\-mno\-flush\-func\fR" 4 .IX Item "-mno-flush-func" .PD Specifies the function to call to flush the I and D caches, or to not @@ -6692,72 +7564,152 @@ call any such function. If called, the function must take the same arguments as the common \f(CW\*(C`_flush_func()\*(C'\fR, that is, the address of the memory range for which the cache is being flushed, the size of the memory range, and the number 3 (to flush both caches). The default -depends on the target gcc was configured for, but commonly is either +depends on the target \s-1GCC\s0 was configured for, but commonly is either \&\fB_flush_func\fR or \fB_\|_cpu_flush\fR. +.IP "\fB\-mbranch\-likely\fR" 4 +.IX Item "-mbranch-likely" +.PD 0 +.IP "\fB\-mno\-branch\-likely\fR" 4 +.IX Item "-mno-branch-likely" +.PD +Enable or disable use of Branch Likely instructions, regardless of the +default for the selected architecture. By default, Branch Likely +instructions may be generated if they are supported by the selected +architecture. An exception is for the \s-1MIPS32\s0 and \s-1MIPS64\s0 architectures +and processors which implement those architectures; for those, Branch +Likely instructions will not be generated by default because the \s-1MIPS32\s0 +and \s-1MIPS64\s0 architectures specifically deprecate their use. .PP -These options are defined by the macro -\&\f(CW\*(C`TARGET_SWITCHES\*(C'\fR in the machine description. The default for the -options is also defined by that macro, which enables you to change the -defaults. -.PP -.I "Intel 386 and \s-1AMD\s0 x86\-64 Options" +\fIIntel 386 and \s-1AMD\s0 x86\-64 Options\fR .IX Subsection "Intel 386 and AMD x86-64 Options" .PP These \fB\-m\fR options are defined for the i386 and x86\-64 family of computers: -.Ip "\fB\-mcpu=\fR\fIcpu-type\fR" 4 -.IX Item "-mcpu=cpu-type" +.IP "\fB\-mtune=\fR\fIcpu-type\fR" 4 +.IX Item "-mtune=cpu-type" Tune to \fIcpu-type\fR everything applicable about the generated code, except for the \s-1ABI\s0 and the set of available instructions. The choices for -\&\fIcpu-type\fR are \fBi386\fR, \fBi486\fR, \fBi586\fR, \fBi686\fR, -\&\fBpentium\fR, \fBpentium-mmx\fR, \fBpentiumpro\fR, \fBpentium2\fR, -\&\fBpentium3\fR, \fBpentium4\fR, \fBk6\fR, \fBk6\-2\fR, \fBk6\-3\fR, -\&\fBathlon\fR, \fBathlon-tbird\fR, \fBathlon-4\fR, \fBathlon-xp\fR -and \fBathlon-mp\fR. +\&\fIcpu-type\fR are: +.RS 4 +.IP "\fIi386\fR" 4 +.IX Item "i386" +Original Intel's i386 \s-1CPU\s0. +.IP "\fIi486\fR" 4 +.IX Item "i486" +Intel's i486 \s-1CPU\s0. (No scheduling is implemented for this chip.) +.IP "\fIi586, pentium\fR" 4 +.IX Item "i586, pentium" +Intel Pentium \s-1CPU\s0 with no \s-1MMX\s0 support. +.IP "\fIpentium-mmx\fR" 4 +.IX Item "pentium-mmx" +Intel PentiumMMX \s-1CPU\s0 based on Pentium core with \s-1MMX\s0 instruction set support. +.IP "\fIi686, pentiumpro\fR" 4 +.IX Item "i686, pentiumpro" +Intel PentiumPro \s-1CPU\s0. +.IP "\fIpentium2\fR" 4 +.IX Item "pentium2" +Intel Pentium2 \s-1CPU\s0 based on PentiumPro core with \s-1MMX\s0 instruction set support. +.IP "\fIpentium3, pentium3m\fR" 4 +.IX Item "pentium3, pentium3m" +Intel Pentium3 \s-1CPU\s0 based on PentiumPro core with \s-1MMX\s0 and \s-1SSE\s0 instruction set +support. +.IP "\fIpentium-m\fR" 4 +.IX Item "pentium-m" +Low power version of Intel Pentium3 \s-1CPU\s0 with \s-1MMX\s0, \s-1SSE\s0 and \s-1SSE2\s0 instruction set +support. Used by Centrino notebooks. +.IP "\fIpentium4, pentium4m\fR" 4 +.IX Item "pentium4, pentium4m" +Intel Pentium4 \s-1CPU\s0 with \s-1MMX\s0, \s-1SSE\s0 and \s-1SSE2\s0 instruction set support. +.IP "\fIprescott\fR" 4 +.IX Item "prescott" +Improved version of Intel Pentium4 \s-1CPU\s0 with \s-1MMX\s0, \s-1SSE\s0, \s-1SSE2\s0 and \s-1SSE3\s0 instruction +set support. +.IP "\fInocona\fR" 4 +.IX Item "nocona" +Improved version of Intel Pentium4 \s-1CPU\s0 with 64\-bit extensions, \s-1MMX\s0, \s-1SSE\s0, +\&\s-1SSE2\s0 and \s-1SSE3\s0 instruction set support. +.IP "\fIk6\fR" 4 +.IX Item "k6" +\&\s-1AMD\s0 K6 \s-1CPU\s0 with \s-1MMX\s0 instruction set support. +.IP "\fIk6\-2, k6\-3\fR" 4 +.IX Item "k6-2, k6-3" +Improved versions of \s-1AMD\s0 K6 \s-1CPU\s0 with \s-1MMX\s0 and 3dNOW! instruction set support. +.IP "\fIathlon, athlon-tbird\fR" 4 +.IX Item "athlon, athlon-tbird" +\&\s-1AMD\s0 Athlon \s-1CPU\s0 with \s-1MMX\s0, 3dNOW!, enhanced 3dNOW! and \s-1SSE\s0 prefetch instructions +support. +.IP "\fIathlon\-4, athlon\-xp, athlon-mp\fR" 4 +.IX Item "athlon-4, athlon-xp, athlon-mp" +Improved \s-1AMD\s0 Athlon \s-1CPU\s0 with \s-1MMX\s0, 3dNOW!, enhanced 3dNOW! and full \s-1SSE\s0 +instruction set support. +.IP "\fIk8, opteron, athlon64, athlon-fx\fR" 4 +.IX Item "k8, opteron, athlon64, athlon-fx" +\&\s-1AMD\s0 K8 core based CPUs with x86\-64 instruction set support. (This supersets +\&\s-1MMX\s0, \s-1SSE\s0, \s-1SSE2\s0, 3dNOW!, enhanced 3dNOW! and 64\-bit instruction set extensions.) +.IP "\fIwinchip\-c6\fR" 4 +.IX Item "winchip-c6" +\&\s-1IDT\s0 Winchip C6 \s-1CPU\s0, dealt in same way as i486 with additional \s-1MMX\s0 instruction +set support. +.IP "\fIwinchip2\fR" 4 +.IX Item "winchip2" +\&\s-1IDT\s0 Winchip2 \s-1CPU\s0, dealt in same way as i486 with additional \s-1MMX\s0 and 3dNOW! +instruction set support. +.IP "\fIc3\fR" 4 +.IX Item "c3" +Via C3 \s-1CPU\s0 with \s-1MMX\s0 and 3dNOW! instruction set support. (No scheduling is +implemented for this chip.) +.IP "\fIc3\-2\fR" 4 +.IX Item "c3-2" +Via C3\-2 \s-1CPU\s0 with \s-1MMX\s0 and \s-1SSE\s0 instruction set support. (No scheduling is +implemented for this chip.) +.RE +.RS 4 .Sp While picking a specific \fIcpu-type\fR will schedule things appropriately for that particular chip, the compiler will not generate any code that does not run on the i386 without the \fB\-march=\fR\fIcpu-type\fR option -being used. \fBi586\fR is equivalent to \fBpentium\fR and \fBi686\fR -is equivalent to \fBpentiumpro\fR. \fBk6\fR and \fBathlon\fR are the -\&\s-1AMD\s0 chips as opposed to the Intel ones. -.Ip "\fB\-march=\fR\fIcpu-type\fR" 4 +being used. +.RE +.IP "\fB\-march=\fR\fIcpu-type\fR" 4 .IX Item "-march=cpu-type" Generate instructions for the machine type \fIcpu-type\fR. The choices -for \fIcpu-type\fR are the same as for \fB\-mcpu\fR. Moreover, -specifying \fB\-march=\fR\fIcpu-type\fR implies \fB\-mcpu=\fR\fIcpu-type\fR. -.Ip "\fB\-m386\fR" 4 +for \fIcpu-type\fR are the same as for \fB\-mtune\fR. Moreover, +specifying \fB\-march=\fR\fIcpu-type\fR implies \fB\-mtune=\fR\fIcpu-type\fR. +.IP "\fB\-mcpu=\fR\fIcpu-type\fR" 4 +.IX Item "-mcpu=cpu-type" +A deprecated synonym for \fB\-mtune\fR. +.IP "\fB\-m386\fR" 4 .IX Item "-m386" .PD 0 -.Ip "\fB\-m486\fR" 4 +.IP "\fB\-m486\fR" 4 .IX Item "-m486" -.Ip "\fB\-mpentium\fR" 4 +.IP "\fB\-mpentium\fR" 4 .IX Item "-mpentium" -.Ip "\fB\-mpentiumpro\fR" 4 +.IP "\fB\-mpentiumpro\fR" 4 .IX Item "-mpentiumpro" .PD -These options are synonyms for \fB\-mcpu=i386\fR, \fB\-mcpu=i486\fR, -\&\fB\-mcpu=pentium\fR, and \fB\-mcpu=pentiumpro\fR respectively. +These options are synonyms for \fB\-mtune=i386\fR, \fB\-mtune=i486\fR, +\&\fB\-mtune=pentium\fR, and \fB\-mtune=pentiumpro\fR respectively. These synonyms are deprecated. -.Ip "\fB\-mfpmath=\fR\fIunit\fR" 4 +.IP "\fB\-mfpmath=\fR\fIunit\fR" 4 .IX Item "-mfpmath=unit" -generate floating point arithmetics for selected unit \fIunit\fR. the choices +Generate floating point arithmetics for selected unit \fIunit\fR. The choices for \fIunit\fR are: .RS 4 -.Ip "\fB387\fR" 4 +.IP "\fB387\fR" 4 .IX Item "387" Use the standard 387 floating point coprocessor present majority of chips and emulated otherwise. Code compiled with this option will run almost everywhere. -The temporary results are computed in 80bit precesion instead of precision +The temporary results are computed in 80bit precision instead of precision specified by the type resulting in slightly different results compared to most -of other chips. See \fB\-ffloat-store\fR for more detailed description. +of other chips. See \fB\-ffloat\-store\fR for more detailed description. .Sp This is the default choice for i386 compiler. -.Ip "\fBsse\fR" 4 +.IP "\fBsse\fR" 4 .IX Item "sse" Use scalar floating point instructions present in the \s-1SSE\s0 instruction set. This instruction set is supported by Pentium3 and newer chips, in the \s-1AMD\s0 line -by Athlon-4, Athlon-xp and Athlon-mp chips. The earlier version of \s-1SSE\s0 +by Athlon\-4, Athlon-xp and Athlon-mp chips. The earlier version of \s-1SSE\s0 instruction set supports only single precision arithmetics, thus the double and extended precision arithmetics is still done using 387. Later version, present only in Pentium4 and the future \s-1AMD\s0 x86\-64 chips supports double precision @@ -6767,47 +7719,47 @@ For i387 you need to use \fB\-march=\fR\fIcpu-type\fR, \fB\-msse\fR or \&\fB\-msse2\fR switches to enable \s-1SSE\s0 extensions and make this option effective. For x86\-64 compiler, these extensions are enabled by default. .Sp -The resulting code should be considerably faster in majority of cases and avoid +The resulting code should be considerably faster in the majority of cases and avoid the numerical instability problems of 387 code, but may break some existing code that expects temporaries to be 80bit. .Sp -This is the default choice for x86\-64 compiler. -.Ip "\fBsse,387\fR" 4 +This is the default choice for the x86\-64 compiler. +.IP "\fBsse,387\fR" 4 .IX Item "sse,387" -Attempt to utilize both instruction sets at once. This effectivly double the +Attempt to utilize both instruction sets at once. This effectively double the amount of available registers and on chips with separate execution units for 387 and \s-1SSE\s0 the execution resources too. Use this option with care, as it is -still experimental, because gcc register allocator does not model separate +still experimental, because the \s-1GCC\s0 register allocator does not model separate functional units well resulting in instable performance. .RE .RS 4 .RE -.Ip "\fB\-masm=\fR\fIdialect\fR" 4 +.IP "\fB\-masm=\fR\fIdialect\fR" 4 .IX Item "-masm=dialect" Output asm instructions using selected \fIdialect\fR. Supported choices are \&\fBintel\fR or \fBatt\fR (the default one). -.Ip "\fB\-mieee-fp\fR" 4 +.IP "\fB\-mieee\-fp\fR" 4 .IX Item "-mieee-fp" .PD 0 -.Ip "\fB\-mno-ieee-fp\fR" 4 +.IP "\fB\-mno\-ieee\-fp\fR" 4 .IX Item "-mno-ieee-fp" .PD Control whether or not the compiler uses \s-1IEEE\s0 floating point comparisons. These handle correctly the case where the result of a comparison is unordered. -.Ip "\fB\-msoft-float\fR" 4 +.IP "\fB\-msoft\-float\fR" 4 .IX Item "-msoft-float" Generate output containing library calls for floating point. \&\fBWarning:\fR the requisite libraries are not part of \s-1GCC\s0. Normally the facilities of the machine's usual C compiler are used, but -this can't be done directly in cross-compilation. You must make your +this can't be done directly in cross\-compilation. You must make your own arrangements to provide suitable library functions for -cross-compilation. +cross\-compilation. .Sp On machines where a function returns floating point results in the 80387 register stack, some floating point opcodes may be emitted even if -\&\fB\-msoft-float\fR is used. -.Ip "\fB\-mno-fp-ret-in-387\fR" 4 +\&\fB\-msoft\-float\fR is used. +.IP "\fB\-mno\-fp\-ret\-in\-387\fR" 4 .IX Item "-mno-fp-ret-in-387" Do not use the \s-1FPU\s0 registers for return values of functions. .Sp @@ -6816,9 +7768,9 @@ The usual calling convention has functions return values of types is no \s-1FPU\s0. The idea is that the operating system should emulate an \s-1FPU\s0. .Sp -The option \fB\-mno-fp-ret-in-387\fR causes such values to be returned +The option \fB\-mno\-fp\-ret\-in\-387\fR causes such values to be returned in ordinary \s-1CPU\s0 registers instead. -.Ip "\fB\-mno-fancy-math-387\fR" 4 +.IP "\fB\-mno\-fancy\-math\-387\fR" 4 .IX Item "-mno-fancy-math-387" Some 387 emulators do not support the \f(CW\*(C`sin\*(C'\fR, \f(CW\*(C`cos\*(C'\fR and \&\f(CW\*(C`sqrt\*(C'\fR instructions for the 387. Specify this option to avoid @@ -6827,11 +7779,11 @@ OpenBSD and NetBSD. This option is overridden when \fB\-march\fR indicates that the target cpu will always have an \s-1FPU\s0 and so the instruction will not need emulation. As of revision 2.6.1, these instructions are not generated unless you also use the -\&\fB\-funsafe-math-optimizations\fR switch. -.Ip "\fB\-malign-double\fR" 4 +\&\fB\-funsafe\-math\-optimizations\fR switch. +.IP "\fB\-malign\-double\fR" 4 .IX Item "-malign-double" .PD 0 -.Ip "\fB\-mno-align-double\fR" 4 +.IP "\fB\-mno\-align\-double\fR" 4 .IX Item "-mno-align-double" .PD Control whether \s-1GCC\s0 aligns \f(CW\*(C`double\*(C'\fR, \f(CW\*(C`long double\*(C'\fR, and @@ -6840,36 +7792,49 @@ boundary. Aligning \f(CW\*(C`double\*(C'\fR variables on a two word boundary wi produce code that runs somewhat faster on a \fBPentium\fR at the expense of more memory. .Sp -\&\fBWarning:\fR if you use the \fB\-malign-double\fR switch, +\&\fBWarning:\fR if you use the \fB\-malign\-double\fR switch, structures containing the above types will be aligned differently than the published application binary interface specifications for the 386 and will not be binary compatible with structures in code compiled without that switch. -.Ip "\fB\-m128bit-long-double\fR" 4 -.IX Item "-m128bit-long-double" -Control the size of \f(CW\*(C`long double\*(C'\fR type. i386 application binary interface -specify the size to be 12 bytes, while modern architectures (Pentium and newer) -prefer \f(CW\*(C`long double\*(C'\fR aligned to 8 or 16 byte boundary. This is -impossible to reach with 12 byte long doubles in the array accesses. -.Sp -\&\fBWarning:\fR if you use the \fB\-m128bit-long-double\fR switch, the -structures and arrays containing \f(CW\*(C`long double\*(C'\fR will change their size as -well as function calling convention for function taking \f(CW\*(C`long double\*(C'\fR -will be modified. -.Ip "\fB\-m96bit-long-double\fR" 4 +.IP "\fB\-m96bit\-long\-double\fR" 4 .IX Item "-m96bit-long-double" -Set the size of \f(CW\*(C`long double\*(C'\fR to 96 bits as required by the i386 -application binary interface. This is the default. -.Ip "\fB\-msvr3\-shlib\fR" 4 +.PD 0 +.IP "\fB\-m128bit\-long\-double\fR" 4 +.IX Item "-m128bit-long-double" +.PD +These switches control the size of \f(CW\*(C`long double\*(C'\fR type. The i386 +application binary interface specifies the size to be 96 bits, +so \fB\-m96bit\-long\-double\fR is the default in 32 bit mode. +.Sp +Modern architectures (Pentium and newer) would prefer \f(CW\*(C`long double\*(C'\fR +to be aligned to an 8 or 16 byte boundary. In arrays or structures +conforming to the \s-1ABI\s0, this would not be possible. So specifying a +\&\fB\-m128bit\-long\-double\fR will align \f(CW\*(C`long double\*(C'\fR +to a 16 byte boundary by padding the \f(CW\*(C`long double\*(C'\fR with an additional +32 bit zero. +.Sp +In the x86\-64 compiler, \fB\-m128bit\-long\-double\fR is the default choice as +its \s-1ABI\s0 specifies that \f(CW\*(C`long double\*(C'\fR is to be aligned on 16 byte boundary. +.Sp +Notice that neither of these options enable any extra precision over the x87 +standard of 80 bits for a \f(CW\*(C`long double\*(C'\fR. +.Sp +\&\fBWarning:\fR if you override the default value for your target \s-1ABI\s0, the +structures and arrays containing \f(CW\*(C`long double\*(C'\fR variables will change +their size as well as function calling convention for function taking +\&\f(CW\*(C`long double\*(C'\fR will be modified. Hence they will not be binary +compatible with arrays or structures in code compiled without that switch. +.IP "\fB\-msvr3\-shlib\fR" 4 .IX Item "-msvr3-shlib" .PD 0 -.Ip "\fB\-mno-svr3\-shlib\fR" 4 +.IP "\fB\-mno\-svr3\-shlib\fR" 4 .IX Item "-mno-svr3-shlib" .PD Control whether \s-1GCC\s0 places uninitialized local variables into the \&\f(CW\*(C`bss\*(C'\fR or \f(CW\*(C`data\*(C'\fR segments. \fB\-msvr3\-shlib\fR places them into \f(CW\*(C`bss\*(C'\fR. These options are meaningful only on System V Release 3. -.Ip "\fB\-mrtd\fR" 4 +.IP "\fB\-mrtd\fR" 4 .IX Item "-mrtd" Use a different function-calling convention, in which functions that take a fixed number of arguments return with the \f(CW\*(C`ret\*(C'\fR \fInum\fR @@ -6894,7 +7859,7 @@ functions. In addition, seriously incorrect code will result if you call a function with too many arguments. (Normally, extra arguments are harmlessly ignored.) -.Ip "\fB\-mregparm=\fR\fInum\fR" 4 +.IP "\fB\-mregparm=\fR\fInum\fR" 4 .IX Item "-mregparm=num" Control how many registers are used to pass integer arguments. By default, no registers are used to pass arguments, and at most 3 @@ -6905,16 +7870,16 @@ function by using the function attribute \fBregparm\fR. \&\fInum\fR is nonzero, then you must build all modules with the same value, including any libraries. This includes the system libraries and startup modules. -.Ip "\fB\-mpreferred-stack-boundary=\fR\fInum\fR" 4 +.IP "\fB\-mpreferred\-stack\-boundary=\fR\fInum\fR" 4 .IX Item "-mpreferred-stack-boundary=num" Attempt to keep the stack boundary aligned to a 2 raised to \fInum\fR -byte boundary. If \fB\-mpreferred-stack-boundary\fR is not specified, +byte boundary. If \fB\-mpreferred\-stack\-boundary\fR is not specified, the default is 4 (16 bytes or 128 bits), except when optimizing for code size (\fB\-Os\fR), in which case the default is the minimum correct alignment (4 bytes for x86, and 8 bytes for x86\-64). .Sp On Pentium and PentiumPro, \f(CW\*(C`double\*(C'\fR and \f(CW\*(C`long double\*(C'\fR values -should be aligned to an 8 byte boundary (see \fB\-malign-double\fR) or +should be aligned to an 8 byte boundary (see \fB\-malign\-double\fR) or suffer significant run time performance penalties. On Pentium \s-1III\s0, the Streaming \s-1SIMD\s0 Extension (\s-1SSE\s0) data type \f(CW\*(C`_\|_m128\*(C'\fR suffers similar penalties if it is not 16 byte aligned. @@ -6930,79 +7895,97 @@ libraries that use callbacks always use the default setting. This extra alignment does consume extra stack space, and generally increases code size. Code that is sensitive to stack space usage, such as embedded systems and operating system kernels, may want to reduce the -preferred alignment to \fB\-mpreferred-stack-boundary=2\fR. -.Ip "\fB\-mmmx\fR" 4 +preferred alignment to \fB\-mpreferred\-stack\-boundary=2\fR. +.IP "\fB\-mmmx\fR" 4 .IX Item "-mmmx" .PD 0 -.Ip "\fB\-mno-mmx\fR" 4 +.IP "\fB\-mno\-mmx\fR" 4 .IX Item "-mno-mmx" -.Ip "\fB\-msse\fR" 4 +.IP "\fB\-msse\fR" 4 .IX Item "-msse" -.Ip "\fB\-mno-sse\fR" 4 +.IP "\fB\-mno\-sse\fR" 4 .IX Item "-mno-sse" -.Ip "\fB\-msse2\fR" 4 +.IP "\fB\-msse2\fR" 4 .IX Item "-msse2" -.Ip "\fB\-mno-sse2\fR" 4 +.IP "\fB\-mno\-sse2\fR" 4 .IX Item "-mno-sse2" -.Ip "\fB\-m3dnow\fR" 4 +.IP "\fB\-msse3\fR" 4 +.IX Item "-msse3" +.IP "\fB\-mno\-sse3\fR" 4 +.IX Item "-mno-sse3" +.IP "\fB\-m3dnow\fR" 4 .IX Item "-m3dnow" -.Ip "\fB\-mno-3dnow\fR" 4 +.IP "\fB\-mno\-3dnow\fR" 4 .IX Item "-mno-3dnow" .PD These switches enable or disable the use of built-in functions that allow -direct access to the \s-1MMX\s0, \s-1SSE\s0 and 3Dnow extensions of the instruction set. +direct access to the \s-1MMX\s0, \s-1SSE\s0, \s-1SSE2\s0, \s-1SSE3\s0 and 3Dnow extensions of the +instruction set. .Sp -To have \s-1SSE/SSE2\s0 instructions generated automatically from floating-point code, -see \fB\-mfpmath=sse\fR. -.Ip "\fB\-mpush-args\fR" 4 +To have \s-1SSE/SSE2\s0 instructions generated automatically from floating-point +code, see \fB\-mfpmath=sse\fR. +.IP "\fB\-mpush\-args\fR" 4 .IX Item "-mpush-args" .PD 0 -.Ip "\fB\-mno-push-args\fR" 4 +.IP "\fB\-mno\-push\-args\fR" 4 .IX Item "-mno-push-args" .PD Use \s-1PUSH\s0 operations to store outgoing parameters. This method is shorter and usually equally fast as method using \s-1SUB/MOV\s0 operations and is enabled by default. In some cases disabling it may improve performance because of improved scheduling and reduced dependencies. -.Ip "\fB\-maccumulate-outgoing-args\fR" 4 +.IP "\fB\-maccumulate\-outgoing\-args\fR" 4 .IX Item "-maccumulate-outgoing-args" If enabled, the maximum amount of space required for outgoing arguments will be computed in the function prologue. This is faster on most modern CPUs because of reduced dependencies, improved scheduling and reduced stack usage when preferred stack boundary is not equal to 2. The drawback is a notable -increase in code size. This switch implies \fB\-mno-push-args\fR. -.Ip "\fB\-mthreads\fR" 4 +increase in code size. This switch implies \fB\-mno\-push\-args\fR. +.IP "\fB\-mthreads\fR" 4 .IX Item "-mthreads" Support thread-safe exception handling on \fBMingw32\fR. Code that relies on thread-safe exception handling must compile and link all code with the \&\fB\-mthreads\fR option. When compiling, \fB\-mthreads\fR defines \&\fB\-D_MT\fR; when linking, it links in a special thread helper library \&\fB\-lmingwthrd\fR which cleans up per thread exception handling data. -.Ip "\fB\-mno-align-stringops\fR" 4 +.IP "\fB\-mno\-align\-stringops\fR" 4 .IX Item "-mno-align-stringops" Do not align destination of inlined string operations. This switch reduces code size and improves performance in case the destination is already aligned, -but gcc don't know about it. -.Ip "\fB\-minline-all-stringops\fR" 4 +but \s-1GCC\s0 doesn't know about it. +.IP "\fB\-minline\-all\-stringops\fR" 4 .IX Item "-minline-all-stringops" By default \s-1GCC\s0 inlines string operations only when destination is known to be aligned at least to 4 byte boundary. This enables more inlining, increase code size, but may improve performance of code that depends on fast memcpy, strlen and memset for short lengths. -.Ip "\fB\-momit-leaf-frame-pointer\fR" 4 +.IP "\fB\-momit\-leaf\-frame\-pointer\fR" 4 .IX Item "-momit-leaf-frame-pointer" Don't keep the frame pointer in a register for leaf functions. This avoids the instructions to save, set up and restore frame pointers and makes an extra register available in leaf functions. The option -\&\fB\-fomit-frame-pointer\fR removes the frame pointer for all functions +\&\fB\-fomit\-frame\-pointer\fR removes the frame pointer for all functions which might make debugging harder. +.IP "\fB\-mtls\-direct\-seg\-refs\fR" 4 +.IX Item "-mtls-direct-seg-refs" +.PD 0 +.IP "\fB\-mno\-tls\-direct\-seg\-refs\fR" 4 +.IX Item "-mno-tls-direct-seg-refs" +.PD +Controls whether \s-1TLS\s0 variables may be accessed with offsets from the +\&\s-1TLS\s0 segment register (\f(CW%gs\fR for 32\-bit, \f(CW%fs\fR for 64\-bit), +or whether the thread base pointer must be added. Whether or not this +is legal depends on the operating system, and whether it maps the +segment to cover the entire \s-1TLS\s0 area. +.Sp +For systems that use \s-1GNU\s0 libc, the default is on. .PP These \fB\-m\fR switches are supported in addition to the above on \s-1AMD\s0 x86\-64 processors in 64\-bit environments. -.Ip "\fB\-m32\fR" 4 +.IP "\fB\-m32\fR" 4 .IX Item "-m32" .PD 0 -.Ip "\fB\-m64\fR" 4 +.IP "\fB\-m64\fR" 4 .IX Item "-m64" .PD Generate code for a 32\-bit or 64\-bit environment. @@ -7010,46 +7993,46 @@ The 32\-bit environment sets int, long and pointer to 32 bits and generates code that runs on any i386 system. The 64\-bit environment sets int to 32 bits and long and pointer to 64 bits and generates code for \s-1AMD\s0's x86\-64 architecture. -.Ip "\fB\-mno-red-zone\fR" 4 +.IP "\fB\-mno\-red\-zone\fR" 4 .IX Item "-mno-red-zone" Do not use a so called red zone for x86\-64 code. The red zone is mandated by the x86\-64 \s-1ABI\s0, it is a 128\-byte area beyond the location of the stack pointer that will not be modified by signal or interrupt handlers and therefore can be used for temporary data without adjusting the stack -pointer. The flag \fB\-mno-red-zone\fR disables this red zone. -.Ip "\fB\-mcmodel=small\fR" 4 +pointer. The flag \fB\-mno\-red\-zone\fR disables this red zone. +.IP "\fB\-mcmodel=small\fR" 4 .IX Item "-mcmodel=small" Generate code for the small code model: the program and its symbols must be linked in the lower 2 \s-1GB\s0 of the address space. Pointers are 64 bits. Programs can be statically or dynamically linked. This is the default code model. -.Ip "\fB\-mcmodel=kernel\fR" 4 +.IP "\fB\-mcmodel=kernel\fR" 4 .IX Item "-mcmodel=kernel" Generate code for the kernel code model. The kernel runs in the negative 2 \s-1GB\s0 of the address space. This model has to be used for Linux kernel code. -.Ip "\fB\-mcmodel=medium\fR" 4 +.IP "\fB\-mcmodel=medium\fR" 4 .IX Item "-mcmodel=medium" Generate code for the medium model: The program is linked in the lower 2 \&\s-1GB\s0 of the address space but symbols can be located anywhere in the address space. Programs can be statically or dynamically linked, but building of shared libraries are not supported with the medium model. -.Ip "\fB\-mcmodel=large\fR" 4 +.IP "\fB\-mcmodel=large\fR" 4 .IX Item "-mcmodel=large" Generate code for the large model: This model makes no assumptions about addresses and sizes of sections. Currently \s-1GCC\s0 does not implement this model. .PP -.I "\s-1HPPA\s0 Options" +\fI\s-1HPPA\s0 Options\fR .IX Subsection "HPPA Options" .PP These \fB\-m\fR options are defined for the \s-1HPPA\s0 family of computers: -.Ip "\fB\-march=\fR\fIarchitecture-type\fR" 4 +.IP "\fB\-march=\fR\fIarchitecture-type\fR" 4 .IX Item "-march=architecture-type" Generate code for the specified architecture. The choices for \&\fIarchitecture-type\fR are \fB1.0\fR for \s-1PA\s0 1.0, \fB1.1\fR for \s-1PA\s0 1.1, and \fB2.0\fR for \s-1PA\s0 2.0 processors. Refer to -\&\fI/usr/lib/sched.models\fR on an \s-1HP-UX\s0 system to determine the proper +\&\fI/usr/lib/sched.models\fR on an HP-UX system to determine the proper architecture option for your machine. Code compiled for lower numbered architectures will run on higher numbered architectures, but not the other way around. @@ -7057,92 +8040,170 @@ other way around. \&\s-1PA\s0 2.0 support currently requires gas snapshot 19990413 or later. The next release of binutils (current is 2.9.1) will probably contain \s-1PA\s0 2.0 support. -.Ip "\fB\-mpa-risc-1\-0\fR" 4 +.IP "\fB\-mpa\-risc\-1\-0\fR" 4 .IX Item "-mpa-risc-1-0" .PD 0 -.Ip "\fB\-mpa-risc-1\-1\fR" 4 +.IP "\fB\-mpa\-risc\-1\-1\fR" 4 .IX Item "-mpa-risc-1-1" -.Ip "\fB\-mpa-risc-2\-0\fR" 4 +.IP "\fB\-mpa\-risc\-2\-0\fR" 4 .IX Item "-mpa-risc-2-0" .PD Synonyms for \fB\-march=1.0\fR, \fB\-march=1.1\fR, and \fB\-march=2.0\fR respectively. -.Ip "\fB\-mbig-switch\fR" 4 +.IP "\fB\-mbig\-switch\fR" 4 .IX Item "-mbig-switch" Generate code suitable for big switch tables. Use this option only if the assembler/linker complain about out of range branches within a switch table. -.Ip "\fB\-mjump-in-delay\fR" 4 +.IP "\fB\-mjump\-in\-delay\fR" 4 .IX Item "-mjump-in-delay" Fill delay slots of function calls with unconditional jump instructions by modifying the return pointer for the function call to be the target of the conditional jump. -.Ip "\fB\-mdisable-fpregs\fR" 4 +.IP "\fB\-mdisable\-fpregs\fR" 4 .IX Item "-mdisable-fpregs" Prevent floating point registers from being used in any manner. This is necessary for compiling kernels which perform lazy context switching of floating point registers. If you use this option and attempt to perform floating point operations, the compiler will abort. -.Ip "\fB\-mdisable-indexing\fR" 4 +.IP "\fB\-mdisable\-indexing\fR" 4 .IX Item "-mdisable-indexing" Prevent the compiler from using indexing address modes. This avoids some rather obscure problems when compiling \s-1MIG\s0 generated code under \s-1MACH\s0. -.Ip "\fB\-mno-space-regs\fR" 4 +.IP "\fB\-mno\-space\-regs\fR" 4 .IX Item "-mno-space-regs" Generate code that assumes the target has no space registers. This allows \&\s-1GCC\s0 to generate faster indirect calls and use unscaled index address modes. .Sp Such code is suitable for level 0 \s-1PA\s0 systems and kernels. -.Ip "\fB\-mfast-indirect-calls\fR" 4 +.IP "\fB\-mfast\-indirect\-calls\fR" 4 .IX Item "-mfast-indirect-calls" Generate code that assumes calls never cross space boundaries. This allows \s-1GCC\s0 to emit code which performs faster indirect calls. .Sp This option will not work in the presence of shared libraries or nested functions. -.Ip "\fB\-mlong-load-store\fR" 4 +.IP "\fB\-mlong\-load\-store\fR" 4 .IX Item "-mlong-load-store" Generate 3\-instruction load and store sequences as sometimes required by -the \s-1HP-UX\s0 10 linker. This is equivalent to the \fB+k\fR option to +the HP-UX 10 linker. This is equivalent to the \fB+k\fR option to the \s-1HP\s0 compilers. -.Ip "\fB\-mportable-runtime\fR" 4 +.IP "\fB\-mportable\-runtime\fR" 4 .IX Item "-mportable-runtime" Use the portable calling conventions proposed by \s-1HP\s0 for \s-1ELF\s0 systems. -.Ip "\fB\-mgas\fR" 4 +.IP "\fB\-mgas\fR" 4 .IX Item "-mgas" Enable the use of assembler directives only \s-1GAS\s0 understands. -.Ip "\fB\-mschedule=\fR\fIcpu-type\fR" 4 +.IP "\fB\-mschedule=\fR\fIcpu-type\fR" 4 .IX Item "-mschedule=cpu-type" Schedule code according to the constraints for the machine type \&\fIcpu-type\fR. The choices for \fIcpu-type\fR are \fB700\fR -\&\fB7100\fR, \fB7100LC\fR, \fB7200\fR, and \fB8000\fR. Refer to -\&\fI/usr/lib/sched.models\fR on an \s-1HP-UX\s0 system to determine the -proper scheduling option for your machine. -.Ip "\fB\-mlinker-opt\fR" 4 +\&\fB7100\fR, \fB7100LC\fR, \fB7200\fR, \fB7300\fR and \fB8000\fR. Refer +to \fI/usr/lib/sched.models\fR on an HP-UX system to determine the +proper scheduling option for your machine. The default scheduling is +\&\fB8000\fR. +.IP "\fB\-mlinker\-opt\fR" 4 .IX Item "-mlinker-opt" -Enable the optimization pass in the \s-1HPUX\s0 linker. Note this makes symbolic -debugging impossible. It also triggers a bug in the \s-1HPUX\s0 8 and \s-1HPUX\s0 9 linkers -in which they give bogus error messages when linking some programs. -.Ip "\fB\-msoft-float\fR" 4 +Enable the optimization pass in the HP-UX linker. Note this makes symbolic +debugging impossible. It also triggers a bug in the HP-UX 8 and HP-UX 9 +linkers in which they give bogus error messages when linking some programs. +.IP "\fB\-msoft\-float\fR" 4 .IX Item "-msoft-float" Generate output containing library calls for floating point. \&\fBWarning:\fR the requisite libraries are not available for all \s-1HPPA\s0 targets. Normally the facilities of the machine's usual C compiler are -used, but this cannot be done directly in cross-compilation. You must make +used, but this cannot be done directly in cross\-compilation. You must make your own arrangements to provide suitable library functions for -cross-compilation. The embedded target \fBhppa1.1\-*\-pro\fR +cross\-compilation. The embedded target \fBhppa1.1\-*\-pro\fR does provide software floating point support. .Sp -\&\fB\-msoft-float\fR changes the calling convention in the output file; +\&\fB\-msoft\-float\fR changes the calling convention in the output file; therefore, it is only useful if you compile \fIall\fR of a program with this option. In particular, you need to compile \fIlibgcc.a\fR, the -library that comes with \s-1GCC\s0, with \fB\-msoft-float\fR in order for +library that comes with \s-1GCC\s0, with \fB\-msoft\-float\fR in order for this to work. +.IP "\fB\-msio\fR" 4 +.IX Item "-msio" +Generate the predefine, \f(CW\*(C`_SIO\*(C'\fR, for server \s-1IO\s0. The default is +\&\fB\-mwsio\fR. This generates the predefines, \f(CW\*(C`_\|_hp9000s700\*(C'\fR, +\&\f(CW\*(C`_\|_hp9000s700_\|_\*(C'\fR and \f(CW\*(C`_WSIO\*(C'\fR, for workstation \s-1IO\s0. These +options are available under HP-UX and \s-1HI\-UX\s0. +.IP "\fB\-mgnu\-ld\fR" 4 +.IX Item "-mgnu-ld" +Use \s-1GNU\s0 ld specific options. This passes \fB\-shared\fR to ld when +building a shared library. It is the default when \s-1GCC\s0 is configured, +explicitly or implicitly, with the \s-1GNU\s0 linker. This option does not +have any affect on which ld is called, it only changes what parameters +are passed to that ld. The ld that is called is determined by the +\&\fB\-\-with\-ld\fR configure option, \s-1GCC\s0's program search path, and +finally by the user's \fB\s-1PATH\s0\fR. The linker used by \s-1GCC\s0 can be printed +using \fBwhich `gcc \-print\-prog\-name=ld`\fR. This option is only available +on the 64 bit HP-UX \s-1GCC\s0, i.e. configured with \fBhppa*64*\-*\-hpux*\fR. +.IP "\fB\-mhp\-ld\fR" 4 +.IX Item "-mhp-ld" +Use \s-1HP\s0 ld specific options. This passes \fB\-b\fR to ld when building +a shared library and passes \fB+Accept TypeMismatch\fR to ld on all +links. It is the default when \s-1GCC\s0 is configured, explicitly or +implicitly, with the \s-1HP\s0 linker. This option does not have any affect on +which ld is called, it only changes what parameters are passed to that +ld. The ld that is called is determined by the \fB\-\-with\-ld\fR +configure option, \s-1GCC\s0's program search path, and finally by the user's +\&\fB\s-1PATH\s0\fR. The linker used by \s-1GCC\s0 can be printed using \fBwhich +`gcc \-print\-prog\-name=ld`\fR. This option is only available on the 64 bit +HP-UX \s-1GCC\s0, i.e. configured with \fBhppa*64*\-*\-hpux*\fR. +.IP "\fB\-mlong\-calls\fR" 4 +.IX Item "-mlong-calls" +Generate code that uses long call sequences. This ensures that a call +is always able to reach linker generated stubs. The default is to generate +long calls only when the distance from the call site to the beginning +of the function or translation unit, as the case may be, exceeds a +predefined limit set by the branch type being used. The limits for +normal calls are 7,600,000 and 240,000 bytes, respectively for the +\&\s-1PA\s0 2.0 and \s-1PA\s0 1.X architectures. Sibcalls are always limited at +240,000 bytes. +.Sp +Distances are measured from the beginning of functions when using the +\&\fB\-ffunction\-sections\fR option, or when using the \fB\-mgas\fR +and \fB\-mno\-portable\-runtime\fR options together under HP-UX with +the \s-1SOM\s0 linker. +.Sp +It is normally not desirable to use this option as it will degrade +performance. However, it may be useful in large applications, +particularly when partial linking is used to build the application. +.Sp +The types of long calls used depends on the capabilities of the +assembler and linker, and the type of code being generated. The +impact on systems that support long absolute calls, and long pic +symbol-difference or pc-relative calls should be relatively small. +However, an indirect call is used on 32\-bit \s-1ELF\s0 systems in pic code +and it is quite long. +.IP "\fB\-nolibdld\fR" 4 +.IX Item "-nolibdld" +Suppress the generation of link options to search libdld.sl when the +\&\fB\-static\fR option is specified on HP-UX 10 and later. +.IP "\fB\-static\fR" 4 +.IX Item "-static" +The HP-UX implementation of setlocale in libc has a dependency on +libdld.sl. There isn't an archive version of libdld.sl. Thus, +when the \fB\-static\fR option is specified, special link options +are needed to resolve this dependency. +.Sp +On HP-UX 10 and later, the \s-1GCC\s0 driver adds the necessary options to +link with libdld.sl when the \fB\-static\fR option is specified. +This causes the resulting binary to be dynamic. On the 64\-bit port, +the linkers generate dynamic binaries by default in any case. The +\&\fB\-nolibdld\fR option can be used to prevent the \s-1GCC\s0 driver from +adding these link options. +.IP "\fB\-threads\fR" 4 +.IX Item "-threads" +Add support for multithreading with the \fIdce thread\fR library +under \s-1HP\-UX\s0. This option sets flags for both the preprocessor and +linker. .PP -.I "Intel 960 Options" +\fIIntel 960 Options\fR .IX Subsection "Intel 960 Options" .PP These \fB\-m\fR options are defined for the Intel 960 implementations: -.Ip "\fB\-m\fR\fIcpu-type\fR" 4 +.IP "\fB\-m\fR\fIcpu-type\fR" 4 .IX Item "-mcpu-type" Assume the defaults for the machine type \fIcpu-type\fR for some of the other options, including instruction scheduling, floating point @@ -7151,19 +8212,19 @@ support, and addressing modes. The choices for \fIcpu-type\fR are \&\fBsa\fR, and \fBsb\fR. The default is \&\fBkb\fR. -.Ip "\fB\-mnumerics\fR" 4 +.IP "\fB\-mnumerics\fR" 4 .IX Item "-mnumerics" .PD 0 -.Ip "\fB\-msoft-float\fR" 4 +.IP "\fB\-msoft\-float\fR" 4 .IX Item "-msoft-float" .PD The \fB\-mnumerics\fR option indicates that the processor does support -floating-point instructions. The \fB\-msoft-float\fR option indicates +floating-point instructions. The \fB\-msoft\-float\fR option indicates that floating-point support should not be assumed. -.Ip "\fB\-mleaf-procedures\fR" 4 +.IP "\fB\-mleaf\-procedures\fR" 4 .IX Item "-mleaf-procedures" .PD 0 -.Ip "\fB\-mno-leaf-procedures\fR" 4 +.IP "\fB\-mno\-leaf\-procedures\fR" 4 .IX Item "-mno-leaf-procedures" .PD Do (or do not) attempt to alter leaf procedures to be callable with the @@ -7172,84 +8233,84 @@ efficient code for explicit calls when the \f(CW\*(C`bal\*(C'\fR instruction can substituted by the assembler or linker, but less efficient code in other cases, such as calls via function pointers, or using a linker that doesn't support this optimization. -.Ip "\fB\-mtail-call\fR" 4 +.IP "\fB\-mtail\-call\fR" 4 .IX Item "-mtail-call" .PD 0 -.Ip "\fB\-mno-tail-call\fR" 4 +.IP "\fB\-mno\-tail\-call\fR" 4 .IX Item "-mno-tail-call" .PD Do (or do not) make additional attempts (beyond those of the machine-independent portions of the compiler) to optimize tail-recursive calls into branches. You may not want to do this because the detection of cases where this is not valid is not totally complete. The default is -\&\fB\-mno-tail-call\fR. -.Ip "\fB\-mcomplex-addr\fR" 4 +\&\fB\-mno\-tail\-call\fR. +.IP "\fB\-mcomplex\-addr\fR" 4 .IX Item "-mcomplex-addr" .PD 0 -.Ip "\fB\-mno-complex-addr\fR" 4 +.IP "\fB\-mno\-complex\-addr\fR" 4 .IX Item "-mno-complex-addr" .PD Assume (or do not assume) that the use of a complex addressing mode is a win on this implementation of the i960. Complex addressing modes may not -be worthwhile on the K-series, but they definitely are on the C-series. -The default is currently \fB\-mcomplex-addr\fR for all processors except +be worthwhile on the K\-series, but they definitely are on the C\-series. +The default is currently \fB\-mcomplex\-addr\fR for all processors except the \s-1CB\s0 and \s-1CC\s0. -.Ip "\fB\-mcode-align\fR" 4 +.IP "\fB\-mcode\-align\fR" 4 .IX Item "-mcode-align" .PD 0 -.Ip "\fB\-mno-code-align\fR" 4 +.IP "\fB\-mno\-code\-align\fR" 4 .IX Item "-mno-code-align" .PD Align code to 8\-byte boundaries for faster fetching (or don't bother). -Currently turned on by default for C-series implementations only. -.Ip "\fB\-mic-compat\fR" 4 +Currently turned on by default for C\-series implementations only. +.IP "\fB\-mic\-compat\fR" 4 .IX Item "-mic-compat" .PD 0 -.Ip "\fB\-mic2.0\-compat\fR" 4 +.IP "\fB\-mic2.0\-compat\fR" 4 .IX Item "-mic2.0-compat" -.Ip "\fB\-mic3.0\-compat\fR" 4 +.IP "\fB\-mic3.0\-compat\fR" 4 .IX Item "-mic3.0-compat" .PD Enable compatibility with iC960 v2.0 or v3.0. -.Ip "\fB\-masm-compat\fR" 4 +.IP "\fB\-masm\-compat\fR" 4 .IX Item "-masm-compat" .PD 0 -.Ip "\fB\-mintel-asm\fR" 4 +.IP "\fB\-mintel\-asm\fR" 4 .IX Item "-mintel-asm" .PD Enable compatibility with the iC960 assembler. -.Ip "\fB\-mstrict-align\fR" 4 +.IP "\fB\-mstrict\-align\fR" 4 .IX Item "-mstrict-align" .PD 0 -.Ip "\fB\-mno-strict-align\fR" 4 +.IP "\fB\-mno\-strict\-align\fR" 4 .IX Item "-mno-strict-align" .PD Do not permit (do permit) unaligned accesses. -.Ip "\fB\-mold-align\fR" 4 +.IP "\fB\-mold\-align\fR" 4 .IX Item "-mold-align" Enable structure-alignment compatibility with Intel's gcc release version -1.3 (based on gcc 1.37). This option implies \fB\-mstrict-align\fR. -.Ip "\fB\-mlong-double-64\fR" 4 +1.3 (based on gcc 1.37). This option implies \fB\-mstrict\-align\fR. +.IP "\fB\-mlong\-double\-64\fR" 4 .IX Item "-mlong-double-64" Implement type \fBlong double\fR as 64\-bit floating point numbers. Without the option \fBlong double\fR is implemented by 80\-bit floating point numbers. The only reason we have it because there is -no 128\-bit \fBlong double\fR support in \fBfp-bit.c\fR yet. So it +no 128\-bit \fBlong double\fR support in \fBfp\-bit.c\fR yet. So it is only useful for people using soft-float targets. Otherwise, we should recommend against use of it. .PP -.I "\s-1DEC\s0 Alpha Options" +\fI\s-1DEC\s0 Alpha Options\fR .IX Subsection "DEC Alpha Options" .PP These \fB\-m\fR options are defined for the \s-1DEC\s0 Alpha implementations: -.Ip "\fB\-mno-soft-float\fR" 4 +.IP "\fB\-mno\-soft\-float\fR" 4 .IX Item "-mno-soft-float" .PD 0 -.Ip "\fB\-msoft-float\fR" 4 +.IP "\fB\-msoft\-float\fR" 4 .IX Item "-msoft-float" .PD Use (do not use) the hardware floating-point instructions for -floating-point operations. When \fB\-msoft-float\fR is specified, +floating-point operations. When \fB\-msoft\-float\fR is specified, functions in \fIlibgcc.a\fR will be used to perform floating-point operations. Unless they are replaced by routines that emulate the floating-point operations, or compiled in such a way as to call such @@ -7260,24 +8321,24 @@ them. .Sp Note that Alpha implementations without floating-point operations are required to have floating-point registers. -.Ip "\fB\-mfp-reg\fR" 4 +.IP "\fB\-mfp\-reg\fR" 4 .IX Item "-mfp-reg" .PD 0 -.Ip "\fB\-mno-fp-regs\fR" 4 +.IP "\fB\-mno\-fp\-regs\fR" 4 .IX Item "-mno-fp-regs" .PD Generate code that uses (does not use) the floating-point register set. -\&\fB\-mno-fp-regs\fR implies \fB\-msoft-float\fR. If the floating-point +\&\fB\-mno\-fp\-regs\fR implies \fB\-msoft\-float\fR. If the floating-point register set is not used, floating point operands are passed in integer registers as if they were integers and floating-point results are passed -in \f(CW\*(C`$0\*(C'\fR instead of \f(CW\*(C`$f0\*(C'\fR. This is a non-standard calling sequence, +in \f(CW$0\fR instead of \f(CW$f0\fR. This is a non-standard calling sequence, so any function with a floating-point argument or return value called by code -compiled with \fB\-mno-fp-regs\fR must also be compiled with that +compiled with \fB\-mno\-fp\-regs\fR must also be compiled with that option. .Sp A typical use of this option is building a kernel that does not use, and hence need not save and restore, any floating-point registers. -.Ip "\fB\-mieee\fR" 4 +.IP "\fB\-mieee\fR" 4 .IX Item "-mieee" The Alpha architecture implements floating-point hardware optimized for maximum performance. It is mostly compliant with the \s-1IEEE\s0 floating @@ -7289,7 +8350,7 @@ defined during compilation. The resulting code is less efficient but is able to correctly support denormalized numbers and exceptional \s-1IEEE\s0 values such as not-a-number and plus/minus infinity. Other Alpha compilers call this option \fB\-ieee_with_no_inexact\fR. -.Ip "\fB\-mieee-with-inexact\fR" 4 +.IP "\fB\-mieee\-with\-inexact\fR" 4 .IX Item "-mieee-with-inexact" This is like \fB\-mieee\fR except the generated code also maintains the \s-1IEEE\s0 \fIinexact-flag\fR. Turning on this option causes the @@ -7300,49 +8361,49 @@ significantly slower than the code generated by default. Since there is very little code that depends on the \fIinexact-flag\fR, you should normally not specify this option. Other Alpha compilers call this option \fB\-ieee_with_inexact\fR. -.Ip "\fB\-mfp-trap-mode=\fR\fItrap-mode\fR" 4 +.IP "\fB\-mfp\-trap\-mode=\fR\fItrap-mode\fR" 4 .IX Item "-mfp-trap-mode=trap-mode" This option controls what floating-point related traps are enabled. Other Alpha compilers call this option \fB\-fptm\fR \fItrap-mode\fR. The trap mode can be set to one of four values: .RS 4 -.Ip "\fBn\fR" 4 +.IP "\fBn\fR" 4 .IX Item "n" This is the default (normal) setting. The only traps that are enabled are the ones that cannot be disabled in software (e.g., division by zero trap). -.Ip "\fBu\fR" 4 +.IP "\fBu\fR" 4 .IX Item "u" In addition to the traps enabled by \fBn\fR, underflow traps are enabled as well. -.Ip "\fBsu\fR" 4 +.IP "\fBsu\fR" 4 .IX Item "su" Like \fBsu\fR, but the instructions are marked to be safe for software completion (see Alpha architecture manual for details). -.Ip "\fBsui\fR" 4 +.IP "\fBsui\fR" 4 .IX Item "sui" Like \fBsu\fR, but inexact traps are enabled as well. .RE .RS 4 .RE -.Ip "\fB\-mfp-rounding-mode=\fR\fIrounding-mode\fR" 4 +.IP "\fB\-mfp\-rounding\-mode=\fR\fIrounding-mode\fR" 4 .IX Item "-mfp-rounding-mode=rounding-mode" Selects the \s-1IEEE\s0 rounding mode. Other Alpha compilers call this option \&\fB\-fprm\fR \fIrounding-mode\fR. The \fIrounding-mode\fR can be one of: .RS 4 -.Ip "\fBn\fR" 4 +.IP "\fBn\fR" 4 .IX Item "n" Normal \s-1IEEE\s0 rounding mode. Floating point numbers are rounded towards the nearest machine number or towards the even machine number in case of a tie. -.Ip "\fBm\fR" 4 +.IP "\fBm\fR" 4 .IX Item "m" Round towards minus infinity. -.Ip "\fBc\fR" 4 +.IP "\fBc\fR" 4 .IX Item "c" Chopped rounding mode. Floating point numbers are rounded towards zero. -.Ip "\fBd\fR" 4 +.IP "\fBd\fR" 4 .IX Item "d" Dynamic rounding mode. A field in the floating point control register (\fIfpcr\fR, see Alpha architecture reference manual) controls the @@ -7352,7 +8413,7 @@ rounding towards plus infinity. Thus, unless your program modifies the .RE .RS 4 .RE -.Ip "\fB\-mtrap-precision=\fR\fItrap-precision\fR" 4 +.IP "\fB\-mtrap\-precision=\fR\fItrap-precision\fR" 4 .IX Item "-mtrap-precision=trap-precision" In the Alpha architecture, floating point traps are imprecise. This means without software assistance it is impossible to recover from a @@ -7362,15 +8423,15 @@ in determining the exact location that caused a floating point trap. Depending on the requirements of an application, different levels of precisions can be selected: .RS 4 -.Ip "\fBp\fR" 4 +.IP "\fBp\fR" 4 .IX Item "p" Program precision. This option is the default and means a trap handler can only identify which program caused a floating point exception. -.Ip "\fBf\fR" 4 +.IP "\fBf\fR" 4 .IX Item "f" Function precision. The trap handler can determine the function that caused a floating point exception. -.Ip "\fBi\fR" 4 +.IP "\fBi\fR" 4 .IX Item "i" Instruction precision. The trap handler can determine the exact instruction that caused a floating point exception. @@ -7380,15 +8441,15 @@ instruction that caused a floating point exception. Other Alpha compilers provide the equivalent options called \&\fB\-scope_safe\fR and \fB\-resumption_safe\fR. .RE -.Ip "\fB\-mieee-conformant\fR" 4 +.IP "\fB\-mieee\-conformant\fR" 4 .IX Item "-mieee-conformant" This option marks the generated code as \s-1IEEE\s0 conformant. You must not -use this option unless you also specify \fB\-mtrap-precision=i\fR and either -\&\fB\-mfp-trap-mode=su\fR or \fB\-mfp-trap-mode=sui\fR. Its only effect +use this option unless you also specify \fB\-mtrap\-precision=i\fR and either +\&\fB\-mfp\-trap\-mode=su\fR or \fB\-mfp\-trap\-mode=sui\fR. Its only effect is to emit the line \fB.eflag 48\fR in the function prologue of the generated assembly file. Under \s-1DEC\s0 Unix, this has the effect that IEEE-conformant math library routines will be linked in. -.Ip "\fB\-mbuild-constants\fR" 4 +.IP "\fB\-mbuild\-constants\fR" 4 .IX Item "-mbuild-constants" Normally \s-1GCC\s0 examines a 32\- or 64\-bit integer constant to see if it can construct it from smaller constants in two or three @@ -7401,79 +8462,93 @@ using code, even if it takes more instructions (the maximum is six). You would typically use this option to build a shared library dynamic loader. Itself a shared library, it must relocate itself in memory before it can find the variables and constants in its own data segment. -.Ip "\fB\-malpha-as\fR" 4 +.IP "\fB\-malpha\-as\fR" 4 .IX Item "-malpha-as" .PD 0 -.Ip "\fB\-mgas\fR" 4 +.IP "\fB\-mgas\fR" 4 .IX Item "-mgas" .PD Select whether to generate code to be assembled by the vendor-supplied -assembler (\fB\-malpha-as\fR) or by the \s-1GNU\s0 assembler \fB\-mgas\fR. -.Ip "\fB\-mbwx\fR" 4 +assembler (\fB\-malpha\-as\fR) or by the \s-1GNU\s0 assembler \fB\-mgas\fR. +.IP "\fB\-mbwx\fR" 4 .IX Item "-mbwx" .PD 0 -.Ip "\fB\-mno-bwx\fR" 4 +.IP "\fB\-mno\-bwx\fR" 4 .IX Item "-mno-bwx" -.Ip "\fB\-mcix\fR" 4 +.IP "\fB\-mcix\fR" 4 .IX Item "-mcix" -.Ip "\fB\-mno-cix\fR" 4 +.IP "\fB\-mno\-cix\fR" 4 .IX Item "-mno-cix" -.Ip "\fB\-mfix\fR" 4 +.IP "\fB\-mfix\fR" 4 .IX Item "-mfix" -.Ip "\fB\-mno-fix\fR" 4 +.IP "\fB\-mno\-fix\fR" 4 .IX Item "-mno-fix" -.Ip "\fB\-mmax\fR" 4 +.IP "\fB\-mmax\fR" 4 .IX Item "-mmax" -.Ip "\fB\-mno-max\fR" 4 +.IP "\fB\-mno\-max\fR" 4 .IX Item "-mno-max" .PD Indicate whether \s-1GCC\s0 should generate code to use the optional \s-1BWX\s0, \&\s-1CIX\s0, \s-1FIX\s0 and \s-1MAX\s0 instruction sets. The default is to use the instruction sets supported by the \s-1CPU\s0 type specified via \fB\-mcpu=\fR option or that of the \s-1CPU\s0 on which \s-1GCC\s0 was built if none was specified. -.Ip "\fB\-mfloat-vax\fR" 4 +.IP "\fB\-mfloat\-vax\fR" 4 .IX Item "-mfloat-vax" .PD 0 -.Ip "\fB\-mfloat-ieee\fR" 4 +.IP "\fB\-mfloat\-ieee\fR" 4 .IX Item "-mfloat-ieee" .PD Generate code that uses (does not use) \s-1VAX\s0 F and G floating point arithmetic instead of \s-1IEEE\s0 single and double precision. -.Ip "\fB\-mexplicit-relocs\fR" 4 +.IP "\fB\-mexplicit\-relocs\fR" 4 .IX Item "-mexplicit-relocs" .PD 0 -.Ip "\fB\-mno-explicit-relocs\fR" 4 +.IP "\fB\-mno\-explicit\-relocs\fR" 4 .IX Item "-mno-explicit-relocs" .PD Older Alpha assemblers provided no way to generate symbol relocations except via assembler macros. Use of these macros does not allow -optimial instruction scheduling. \s-1GNU\s0 binutils as of version 2.12 +optimal instruction scheduling. \s-1GNU\s0 binutils as of version 2.12 supports a new syntax that allows the compiler to explicitly mark which relocations should apply to which instructions. This option is mostly useful for debugging, as \s-1GCC\s0 detects the capabilities of the assembler when it is built and sets the default accordingly. -.Ip "\fB\-msmall-data\fR" 4 +.IP "\fB\-msmall\-data\fR" 4 .IX Item "-msmall-data" .PD 0 -.Ip "\fB\-mlarge-data\fR" 4 +.IP "\fB\-mlarge\-data\fR" 4 .IX Item "-mlarge-data" .PD -When \fB\-mexplicit-relocs\fR is in effect, static data is -accessed via \fIgp-relative\fR relocations. When \fB\-msmall-data\fR +When \fB\-mexplicit\-relocs\fR is in effect, static data is +accessed via \fIgp-relative\fR relocations. When \fB\-msmall\-data\fR is used, objects 8 bytes long or smaller are placed in a \fIsmall data area\fR (the \f(CW\*(C`.sdata\*(C'\fR and \f(CW\*(C`.sbss\*(C'\fR sections) and are accessed via -16\-bit relocations off of the \f(CW\*(C`$gp\*(C'\fR register. This limits the +16\-bit relocations off of the \f(CW$gp\fR register. This limits the size of the small data area to 64KB, but allows the variables to be directly accessed via a single instruction. .Sp -The default is \fB\-mlarge-data\fR. With this option the data area +The default is \fB\-mlarge\-data\fR. With this option the data area is limited to just below 2GB. Programs that require more than 2GB of data must use \f(CW\*(C`malloc\*(C'\fR or \f(CW\*(C`mmap\*(C'\fR to allocate the data in the heap instead of in the program's data segment. .Sp When generating code for shared libraries, \fB\-fpic\fR implies -\&\fB\-msmall-data\fR and \fB\-fPIC\fR implies \fB\-mlarge-data\fR. -.Ip "\fB\-mcpu=\fR\fIcpu_type\fR" 4 +\&\fB\-msmall\-data\fR and \fB\-fPIC\fR implies \fB\-mlarge\-data\fR. +.IP "\fB\-msmall\-text\fR" 4 +.IX Item "-msmall-text" +.PD 0 +.IP "\fB\-mlarge\-text\fR" 4 +.IX Item "-mlarge-text" +.PD +When \fB\-msmall\-text\fR is used, the compiler assumes that the +code of the entire program (or shared library) fits in 4MB, and is +thus reachable with a branch instruction. When \fB\-msmall\-data\fR +is used, the compiler can assume that all local symbols share the +same \f(CW$gp\fR value, and thus reduce the number of instructions +required for a function call from 4 to 1. +.Sp +The default is \fB\-mlarge\-text\fR. +.IP "\fB\-mcpu=\fR\fIcpu_type\fR" 4 .IX Item "-mcpu=cpu_type" Set the instruction set and instruction scheduling parameters for machine type \fIcpu_type\fR. You can specify either the \fB\s-1EV\s0\fR @@ -7485,60 +8560,60 @@ to the processor on which the compiler was built. .Sp Supported values for \fIcpu_type\fR are .RS 4 -.Ip "\fBev4\fR" 4 +.IP "\fBev4\fR" 4 .IX Item "ev4" .PD 0 -.Ip "\fBev45\fR" 4 +.IP "\fBev45\fR" 4 .IX Item "ev45" -.Ip "\fB21064\fR" 4 +.IP "\fB21064\fR" 4 .IX Item "21064" .PD Schedules as an \s-1EV4\s0 and has no instruction set extensions. -.Ip "\fBev5\fR" 4 +.IP "\fBev5\fR" 4 .IX Item "ev5" .PD 0 -.Ip "\fB21164\fR" 4 +.IP "\fB21164\fR" 4 .IX Item "21164" .PD Schedules as an \s-1EV5\s0 and has no instruction set extensions. -.Ip "\fBev56\fR" 4 +.IP "\fBev56\fR" 4 .IX Item "ev56" .PD 0 -.Ip "\fB21164a\fR" 4 +.IP "\fB21164a\fR" 4 .IX Item "21164a" .PD Schedules as an \s-1EV5\s0 and supports the \s-1BWX\s0 extension. -.Ip "\fBpca56\fR" 4 +.IP "\fBpca56\fR" 4 .IX Item "pca56" .PD 0 -.Ip "\fB21164pc\fR" 4 +.IP "\fB21164pc\fR" 4 .IX Item "21164pc" -.Ip "\fB21164PC\fR" 4 +.IP "\fB21164PC\fR" 4 .IX Item "21164PC" .PD Schedules as an \s-1EV5\s0 and supports the \s-1BWX\s0 and \s-1MAX\s0 extensions. -.Ip "\fBev6\fR" 4 +.IP "\fBev6\fR" 4 .IX Item "ev6" .PD 0 -.Ip "\fB21264\fR" 4 +.IP "\fB21264\fR" 4 .IX Item "21264" .PD Schedules as an \s-1EV6\s0 and supports the \s-1BWX\s0, \s-1FIX\s0, and \s-1MAX\s0 extensions. -.Ip "\fBev67\fR" 4 +.IP "\fBev67\fR" 4 .IX Item "ev67" .PD 0 -.Ip "\fB21264a\fR" 4 +.IP "\fB21264a\fR" 4 .IX Item "21264a" .PD Schedules as an \s-1EV6\s0 and supports the \s-1BWX\s0, \s-1CIX\s0, \s-1FIX\s0, and \s-1MAX\s0 extensions. .RE .RS 4 .RE -.Ip "\fB\-mtune=\fR\fIcpu_type\fR" 4 +.IP "\fB\-mtune=\fR\fIcpu_type\fR" 4 .IX Item "-mtune=cpu_type" Set only the instruction scheduling parameters for machine type \&\fIcpu_type\fR. The instruction set is not changed. -.Ip "\fB\-mmemory-latency=\fR\fItime\fR" 4 +.IP "\fB\-mmemory\-latency=\fR\fItime\fR" 4 .IX Item "-mmemory-latency=time" Sets the latency the scheduler should assume for typical memory references as seen by the application. This number is highly @@ -7547,17 +8622,17 @@ and the size of the external cache on the machine. .Sp Valid options for \fItime\fR are .RS 4 -.Ip "\fInumber\fR" 4 +.IP "\fInumber\fR" 4 .IX Item "number" A decimal number representing clock cycles. -.Ip "\fBL1\fR" 4 +.IP "\fBL1\fR" 4 .IX Item "L1" .PD 0 -.Ip "\fBL2\fR" 4 +.IP "\fBL2\fR" 4 .IX Item "L2" -.Ip "\fBL3\fR" 4 +.IP "\fBL3\fR" 4 .IX Item "L3" -.Ip "\fBmain\fR" 4 +.IP "\fBmain\fR" 4 .IX Item "main" .PD The compiler contains estimates of the number of clock cycles for @@ -7568,183 +8643,178 @@ Note that L3 is only valid for \s-1EV5\s0. .RS 4 .RE .PP -.I "\s-1DEC\s0 Alpha/VMS Options" +\fI\s-1DEC\s0 Alpha/VMS Options\fR .IX Subsection "DEC Alpha/VMS Options" .PP These \fB\-m\fR options are defined for the \s-1DEC\s0 Alpha/VMS implementations: -.Ip "\fB\-mvms-return-codes\fR" 4 +.IP "\fB\-mvms\-return\-codes\fR" 4 .IX Item "-mvms-return-codes" Return \s-1VMS\s0 condition codes from main. The default is to return \s-1POSIX\s0 style condition (e.g. error) codes. .PP -.I "Clipper Options" -.IX Subsection "Clipper Options" -.PP -These \fB\-m\fR options are defined for the Clipper implementations: -.Ip "\fB\-mc300\fR" 4 -.IX Item "-mc300" -Produce code for a C300 Clipper processor. This is the default. -.Ip "\fB\-mc400\fR" 4 -.IX Item "-mc400" -Produce code for a C400 Clipper processor, i.e. use floating point -registers f8\*(--f15. -.PP -.I "H8/300 Options" +\fIH8/300 Options\fR .IX Subsection "H8/300 Options" .PP These \fB\-m\fR options are defined for the H8/300 implementations: -.Ip "\fB\-mrelax\fR" 4 +.IP "\fB\-mrelax\fR" 4 .IX Item "-mrelax" Shorten some address references at link time, when possible; uses the linker option \fB\-relax\fR. -.Ip "\fB\-mh\fR" 4 +.IP "\fB\-mh\fR" 4 .IX Item "-mh" Generate code for the H8/300H. -.Ip "\fB\-ms\fR" 4 +.IP "\fB\-ms\fR" 4 .IX Item "-ms" -Generate code for the H8/S. -.Ip "\fB\-ms2600\fR" 4 +Generate code for the H8S. +.IP "\fB\-mn\fR" 4 +.IX Item "-mn" +Generate code for the H8S and H8/300H in the normal mode. This switch +must be used either with \-mh or \-ms. +.IP "\fB\-ms2600\fR" 4 .IX Item "-ms2600" -Generate code for the H8/S2600. This switch must be used with \fB\-ms\fR. -.Ip "\fB\-mint32\fR" 4 +Generate code for the H8S/2600. This switch must be used with \fB\-ms\fR. +.IP "\fB\-mint32\fR" 4 .IX Item "-mint32" Make \f(CW\*(C`int\*(C'\fR data 32 bits by default. -.Ip "\fB\-malign-300\fR" 4 +.IP "\fB\-malign\-300\fR" 4 .IX Item "-malign-300" -On the H8/300H and H8/S, use the same alignment rules as for the H8/300. -The default for the H8/300H and H8/S is to align longs and floats on 4 +On the H8/300H and H8S, use the same alignment rules as for the H8/300. +The default for the H8/300H and H8S is to align longs and floats on 4 byte boundaries. -\&\fB\-malign-300\fR causes them to be aligned on 2 byte boundaries. +\&\fB\-malign\-300\fR causes them to be aligned on 2 byte boundaries. This option has no effect on the H8/300. .PP -.I "\s-1SH\s0 Options" +\fI\s-1SH\s0 Options\fR .IX Subsection "SH Options" .PP These \fB\-m\fR options are defined for the \s-1SH\s0 implementations: -.Ip "\fB\-m1\fR" 4 +.IP "\fB\-m1\fR" 4 .IX Item "-m1" Generate code for the \s-1SH1\s0. -.Ip "\fB\-m2\fR" 4 +.IP "\fB\-m2\fR" 4 .IX Item "-m2" Generate code for the \s-1SH2\s0. -.Ip "\fB\-m3\fR" 4 +.IP "\fB\-m2e\fR" 4 +.IX Item "-m2e" +Generate code for the SH2e. +.IP "\fB\-m3\fR" 4 .IX Item "-m3" Generate code for the \s-1SH3\s0. -.Ip "\fB\-m3e\fR" 4 +.IP "\fB\-m3e\fR" 4 .IX Item "-m3e" Generate code for the SH3e. -.Ip "\fB\-m4\-nofpu\fR" 4 +.IP "\fB\-m4\-nofpu\fR" 4 .IX Item "-m4-nofpu" Generate code for the \s-1SH4\s0 without a floating-point unit. -.Ip "\fB\-m4\-single-only\fR" 4 +.IP "\fB\-m4\-single\-only\fR" 4 .IX Item "-m4-single-only" Generate code for the \s-1SH4\s0 with a floating-point unit that only supports single-precision arithmetic. -.Ip "\fB\-m4\-single\fR" 4 +.IP "\fB\-m4\-single\fR" 4 .IX Item "-m4-single" Generate code for the \s-1SH4\s0 assuming the floating-point unit is in single-precision mode by default. -.Ip "\fB\-m4\fR" 4 +.IP "\fB\-m4\fR" 4 .IX Item "-m4" Generate code for the \s-1SH4\s0. -.Ip "\fB\-mb\fR" 4 +.IP "\fB\-mb\fR" 4 .IX Item "-mb" Compile code for the processor in big endian mode. -.Ip "\fB\-ml\fR" 4 +.IP "\fB\-ml\fR" 4 .IX Item "-ml" Compile code for the processor in little endian mode. -.Ip "\fB\-mdalign\fR" 4 +.IP "\fB\-mdalign\fR" 4 .IX Item "-mdalign" Align doubles at 64\-bit boundaries. Note that this changes the calling conventions, and thus some functions from the standard C library will not work unless you recompile it first with \fB\-mdalign\fR. -.Ip "\fB\-mrelax\fR" 4 +.IP "\fB\-mrelax\fR" 4 .IX Item "-mrelax" Shorten some address references at link time, when possible; uses the linker option \fB\-relax\fR. -.Ip "\fB\-mbigtable\fR" 4 +.IP "\fB\-mbigtable\fR" 4 .IX Item "-mbigtable" Use 32\-bit offsets in \f(CW\*(C`switch\*(C'\fR tables. The default is to use 16\-bit offsets. -.Ip "\fB\-mfmovd\fR" 4 +.IP "\fB\-mfmovd\fR" 4 .IX Item "-mfmovd" Enable the use of the instruction \f(CW\*(C`fmovd\*(C'\fR. -.Ip "\fB\-mhitachi\fR" 4 +.IP "\fB\-mhitachi\fR" 4 .IX Item "-mhitachi" -Comply with the calling conventions defined by Hitachi. -.Ip "\fB\-mnomacsave\fR" 4 +Comply with the calling conventions defined by Renesas. +.IP "\fB\-mnomacsave\fR" 4 .IX Item "-mnomacsave" -Mark the \f(CW\*(C`MAC\*(C'\fR register as call-clobbered, even if +Mark the \f(CW\*(C`MAC\*(C'\fR register as call\-clobbered, even if \&\fB\-mhitachi\fR is given. -.Ip "\fB\-mieee\fR" 4 +.IP "\fB\-mieee\fR" 4 .IX Item "-mieee" Increase IEEE-compliance of floating-point code. -.Ip "\fB\-misize\fR" 4 +.IP "\fB\-misize\fR" 4 .IX Item "-misize" Dump instruction size and location in the assembly code. -.Ip "\fB\-mpadstruct\fR" 4 +.IP "\fB\-mpadstruct\fR" 4 .IX Item "-mpadstruct" This option is deprecated. It pads structures to multiple of 4 bytes, which is incompatible with the \s-1SH\s0 \s-1ABI\s0. -.Ip "\fB\-mspace\fR" 4 +.IP "\fB\-mspace\fR" 4 .IX Item "-mspace" Optimize for space instead of speed. Implied by \fB\-Os\fR. -.Ip "\fB\-mprefergot\fR" 4 +.IP "\fB\-mprefergot\fR" 4 .IX Item "-mprefergot" When generating position-independent code, emit function calls using the Global Offset Table instead of the Procedure Linkage Table. -.Ip "\fB\-musermode\fR" 4 +.IP "\fB\-musermode\fR" 4 .IX Item "-musermode" Generate a library function call to invalidate instruction cache entries, after fixing up a trampoline. This library function call doesn't assume it can write to the whole memory address space. This is the default when the target is \f(CW\*(C`sh\-*\-linux*\*(C'\fR. .PP -.I "Options for System V" +\fIOptions for System V\fR .IX Subsection "Options for System V" .PP These additional options are available on System V Release 4 for compatibility with other compilers on those systems: -.Ip "\fB\-G\fR" 4 +.IP "\fB\-G\fR" 4 .IX Item "-G" Create a shared object. It is recommended that \fB\-symbolic\fR or \fB\-shared\fR be used instead. -.Ip "\fB\-Qy\fR" 4 +.IP "\fB\-Qy\fR" 4 .IX Item "-Qy" Identify the versions of each tool used by the compiler, in a \&\f(CW\*(C`.ident\*(C'\fR assembler directive in the output. -.Ip "\fB\-Qn\fR" 4 +.IP "\fB\-Qn\fR" 4 .IX Item "-Qn" Refrain from adding \f(CW\*(C`.ident\*(C'\fR directives to the output file (this is the default). -.Ip "\fB\-YP,\fR\fIdirs\fR" 4 +.IP "\fB\-YP,\fR\fIdirs\fR" 4 .IX Item "-YP,dirs" Search the directories \fIdirs\fR, and no others, for libraries specified with \fB\-l\fR. -.Ip "\fB\-Ym,\fR\fIdir\fR" 4 +.IP "\fB\-Ym,\fR\fIdir\fR" 4 .IX Item "-Ym,dir" Look in the directory \fIdir\fR to find the M4 preprocessor. The assembler uses this option. .PP -.I "TMS320C3x/C4x Options" +\fITMS320C3x/C4x Options\fR .IX Subsection "TMS320C3x/C4x Options" .PP These \fB\-m\fR options are defined for TMS320C3x/C4x implementations: -.Ip "\fB\-mcpu=\fR\fIcpu_type\fR" 4 +.IP "\fB\-mcpu=\fR\fIcpu_type\fR" 4 .IX Item "-mcpu=cpu_type" Set the instruction set, register set, and instruction scheduling parameters for machine type \fIcpu_type\fR. Supported values for \&\fIcpu_type\fR are \fBc30\fR, \fBc31\fR, \fBc32\fR, \fBc40\fR, and \&\fBc44\fR. The default is \fBc40\fR to generate code for the \&\s-1TMS320C40\s0. -.Ip "\fB\-mbig-memory\fR" 4 +.IP "\fB\-mbig\-memory\fR" 4 .IX Item "-mbig-memory" .PD 0 -.Ip "\fB\-mbig\fR" 4 +.IP "\fB\-mbig\fR" 4 .IX Item "-mbig" -.Ip "\fB\-msmall-memory\fR" 4 +.IP "\fB\-msmall\-memory\fR" 4 .IX Item "-msmall-memory" -.Ip "\fB\-msmall\fR" 4 +.IP "\fB\-msmall\fR" 4 .IX Item "-msmall" .PD Generates code for the big or small memory model. The small memory @@ -7753,33 +8823,33 @@ the data page (\s-1DP\s0) register must be set to point to the 64K page containing the .bss and .data program sections. The big memory model is the default and requires reloading of the \s-1DP\s0 register for every direct memory access. -.Ip "\fB\-mbk\fR" 4 +.IP "\fB\-mbk\fR" 4 .IX Item "-mbk" .PD 0 -.Ip "\fB\-mno-bk\fR" 4 +.IP "\fB\-mno\-bk\fR" 4 .IX Item "-mno-bk" .PD Allow (disallow) allocation of general integer operands into the block count register \s-1BK\s0. -.Ip "\fB\-mdb\fR" 4 +.IP "\fB\-mdb\fR" 4 .IX Item "-mdb" .PD 0 -.Ip "\fB\-mno-db\fR" 4 +.IP "\fB\-mno\-db\fR" 4 .IX Item "-mno-db" .PD Enable (disable) generation of code using decrement and branch, -\&\fIDBcond\fR\|(D), instructions. This is enabled by default for the C4x. To be +DBcond(D), instructions. This is enabled by default for the C4x. To be on the safe side, this is disabled for the C3x, since the maximum iteration count on the C3x is 2^{23 + 1} (but who iterates loops more than 2^{23} times on the C3x?). Note that \s-1GCC\s0 will try to reverse a loop so -that it can utilise the decrement and branch instruction, but will give +that it can utilize the decrement and branch instruction, but will give up if there is more than one memory reference in the loop. Thus a loop where the loop counter is decremented can generate slightly more -efficient code, in cases where the \s-1RPTB\s0 instruction cannot be utilised. -.Ip "\fB\-mdp-isr-reload\fR" 4 +efficient code, in cases where the \s-1RPTB\s0 instruction cannot be utilized. +.IP "\fB\-mdp\-isr\-reload\fR" 4 .IX Item "-mdp-isr-reload" .PD 0 -.Ip "\fB\-mparanoid\fR" 4 +.IP "\fB\-mparanoid\fR" 4 .IX Item "-mparanoid" .PD Force the \s-1DP\s0 register to be saved on entry to an interrupt service @@ -7787,10 +8857,10 @@ routine (\s-1ISR\s0), reloaded to point to the data section, and restored on exit from the \s-1ISR\s0. This should not be required unless someone has violated the small memory model by modifying the \s-1DP\s0 register, say within an object library. -.Ip "\fB\-mmpyi\fR" 4 +.IP "\fB\-mmpyi\fR" 4 .IX Item "-mmpyi" .PD 0 -.Ip "\fB\-mno-mpyi\fR" 4 +.IP "\fB\-mno\-mpyi\fR" 4 .IX Item "-mno-mpyi" .PD For the C3x use the 24\-bit \s-1MPYI\s0 instruction for integer multiplies @@ -7798,10 +8868,10 @@ instead of a library call to guarantee 32\-bit results. Note that if one of the operands is a constant, then the multiplication will be performed using shifts and adds. If the \fB\-mmpyi\fR option is not specified for the C3x, then squaring operations are performed inline instead of a library call. -.Ip "\fB\-mfast-fix\fR" 4 +.IP "\fB\-mfast\-fix\fR" 4 .IX Item "-mfast-fix" .PD 0 -.Ip "\fB\-mno-fast-fix\fR" 4 +.IP "\fB\-mno\-fast\-fix\fR" 4 .IX Item "-mno-fast-fix" .PD The C3x/C4x \s-1FIX\s0 instruction to convert a floating point value to an @@ -7811,10 +8881,10 @@ floating point number is negative, the result will be incorrectly truncated an additional code is necessary to detect and correct this case. This option can be used to disable generation of the additional code required to correct the result. -.Ip "\fB\-mrptb\fR" 4 +.IP "\fB\-mrptb\fR" 4 .IX Item "-mrptb" .PD 0 -.Ip "\fB\-mno-rptb\fR" 4 +.IP "\fB\-mno\-rptb\fR" 4 .IX Item "-mno-rptb" .PD Enable (disable) generation of repeat block sequences using the \s-1RPTB\s0 @@ -7823,10 +8893,10 @@ for innermost loops that do not call functions or jump across the loop boundaries. There is no advantage having nested \s-1RPTB\s0 loops due to the overhead required to save and restore the \s-1RC\s0, \s-1RS\s0, and \s-1RE\s0 registers. This is enabled by default with \fB\-O2\fR. -.Ip "\fB\-mrpts=\fR\fIcount\fR" 4 +.IP "\fB\-mrpts=\fR\fIcount\fR" 4 .IX Item "-mrpts=count" .PD 0 -.Ip "\fB\-mno-rpts\fR" 4 +.IP "\fB\-mno\-rpts\fR" 4 .IX Item "-mno-rpts" .PD Enable (disable) the use of the single instruction repeat instruction @@ -7838,10 +8908,10 @@ at compile time. Note that the repeated instruction following \s-1RPTS\s0 does not have to be reloaded from memory each iteration, thus freeing up the \&\s-1CPU\s0 buses for operands. However, since interrupts are blocked by this instruction, it is disabled by default. -.Ip "\fB\-mloop-unsigned\fR" 4 +.IP "\fB\-mloop\-unsigned\fR" 4 .IX Item "-mloop-unsigned" .PD 0 -.Ip "\fB\-mno-loop-unsigned\fR" 4 +.IP "\fB\-mno\-loop\-unsigned\fR" 4 .IX Item "-mno-loop-unsigned" .PD The maximum iteration count when using \s-1RPTS\s0 and \s-1RPTB\s0 (and \s-1DB\s0 on the C40) @@ -7849,112 +8919,140 @@ is 2^{31 + 1} since these instructions test if the iteration count is negative to terminate the loop. If the iteration count is unsigned there is a possibility than the 2^{31 + 1} maximum iteration count may be exceeded. This switch allows an unsigned iteration count. -.Ip "\fB\-mti\fR" 4 +.IP "\fB\-mti\fR" 4 .IX Item "-mti" Try to emit an assembler syntax that the \s-1TI\s0 assembler (asm30) is happy with. This also enforces compatibility with the \s-1API\s0 employed by the \s-1TI\s0 C3x C compiler. For example, long doubles are passed as structures rather than in floating point registers. -.Ip "\fB\-mregparm\fR" 4 +.IP "\fB\-mregparm\fR" 4 .IX Item "-mregparm" .PD 0 -.Ip "\fB\-mmemparm\fR" 4 +.IP "\fB\-mmemparm\fR" 4 .IX Item "-mmemparm" .PD Generate code that uses registers (stack) for passing arguments to functions. By default, arguments are passed in registers where possible rather than by pushing arguments on to the stack. -.Ip "\fB\-mparallel-insns\fR" 4 +.IP "\fB\-mparallel\-insns\fR" 4 .IX Item "-mparallel-insns" .PD 0 -.Ip "\fB\-mno-parallel-insns\fR" 4 +.IP "\fB\-mno\-parallel\-insns\fR" 4 .IX Item "-mno-parallel-insns" .PD Allow the generation of parallel instructions. This is enabled by default with \fB\-O2\fR. -.Ip "\fB\-mparallel-mpy\fR" 4 +.IP "\fB\-mparallel\-mpy\fR" 4 .IX Item "-mparallel-mpy" .PD 0 -.Ip "\fB\-mno-parallel-mpy\fR" 4 +.IP "\fB\-mno\-parallel\-mpy\fR" 4 .IX Item "-mno-parallel-mpy" .PD Allow the generation of MPY||ADD and MPY||SUB parallel instructions, -provided \fB\-mparallel-insns\fR is also specified. These instructions have +provided \fB\-mparallel\-insns\fR is also specified. These instructions have tight register constraints which can pessimize the code generation of large functions. .PP -.I "V850 Options" +\fIV850 Options\fR .IX Subsection "V850 Options" .PP These \fB\-m\fR options are defined for V850 implementations: -.Ip "\fB\-mlong-calls\fR" 4 +.IP "\fB\-mlong\-calls\fR" 4 .IX Item "-mlong-calls" .PD 0 -.Ip "\fB\-mno-long-calls\fR" 4 +.IP "\fB\-mno\-long\-calls\fR" 4 .IX Item "-mno-long-calls" .PD Treat all calls as being far away (near). If calls are assumed to be far away, the compiler will always load the functions address up into a register, and call indirect through the pointer. -.Ip "\fB\-mno-ep\fR" 4 +.IP "\fB\-mno\-ep\fR" 4 .IX Item "-mno-ep" .PD 0 -.Ip "\fB\-mep\fR" 4 +.IP "\fB\-mep\fR" 4 .IX Item "-mep" .PD Do not optimize (do optimize) basic blocks that use the same index pointer 4 or more times to copy pointer into the \f(CW\*(C`ep\*(C'\fR register, and use the shorter \f(CW\*(C`sld\*(C'\fR and \f(CW\*(C`sst\*(C'\fR instructions. The \fB\-mep\fR option is on by default if you optimize. -.Ip "\fB\-mno-prolog-function\fR" 4 +.IP "\fB\-mno\-prolog\-function\fR" 4 .IX Item "-mno-prolog-function" .PD 0 -.Ip "\fB\-mprolog-function\fR" 4 +.IP "\fB\-mprolog\-function\fR" 4 .IX Item "-mprolog-function" .PD -Do not use (do use) external functions to save and restore registers at -the prolog and epilog of a function. The external functions are slower, -but use less code space if more than one function saves the same number -of registers. The \fB\-mprolog-function\fR option is on by default if -you optimize. -.Ip "\fB\-mspace\fR" 4 +Do not use (do use) external functions to save and restore registers +at the prologue and epilogue of a function. The external functions +are slower, but use less code space if more than one function saves +the same number of registers. The \fB\-mprolog\-function\fR option +is on by default if you optimize. +.IP "\fB\-mspace\fR" 4 .IX Item "-mspace" Try to make the code as small as possible. At present, this just turns -on the \fB\-mep\fR and \fB\-mprolog-function\fR options. -.Ip "\fB\-mtda=\fR\fIn\fR" 4 +on the \fB\-mep\fR and \fB\-mprolog\-function\fR options. +.IP "\fB\-mtda=\fR\fIn\fR" 4 .IX Item "-mtda=n" Put static or global variables whose size is \fIn\fR bytes or less into the tiny data area that register \f(CW\*(C`ep\*(C'\fR points to. The tiny data area can hold up to 256 bytes in total (128 bytes for byte references). -.Ip "\fB\-msda=\fR\fIn\fR" 4 +.IP "\fB\-msda=\fR\fIn\fR" 4 .IX Item "-msda=n" Put static or global variables whose size is \fIn\fR bytes or less into the small data area that register \f(CW\*(C`gp\*(C'\fR points to. The small data area can hold up to 64 kilobytes. -.Ip "\fB\-mzda=\fR\fIn\fR" 4 +.IP "\fB\-mzda=\fR\fIn\fR" 4 .IX Item "-mzda=n" Put static or global variables whose size is \fIn\fR bytes or less into the first 32 kilobytes of memory. -.Ip "\fB\-mv850\fR" 4 +.IP "\fB\-mv850\fR" 4 .IX Item "-mv850" Specify that the target processor is the V850. -.Ip "\fB\-mbig-switch\fR" 4 +.IP "\fB\-mbig\-switch\fR" 4 .IX Item "-mbig-switch" Generate code suitable for big switch tables. Use this option only if the assembler/linker complain about out of range branches within a switch table. +.IP "\fB\-mapp\-regs\fR" 4 +.IX Item "-mapp-regs" +This option will cause r2 and r5 to be used in the code generated by +the compiler. This setting is the default. +.IP "\fB\-mno\-app\-regs\fR" 4 +.IX Item "-mno-app-regs" +This option will cause r2 and r5 to be treated as fixed registers. +.IP "\fB\-mv850e1\fR" 4 +.IX Item "-mv850e1" +Specify that the target processor is the V850E1. The preprocessor +constants \fB_\|_v850e1_\|_\fR and \fB_\|_v850e_\|_\fR will be defined if +this option is used. +.IP "\fB\-mv850e\fR" 4 +.IX Item "-mv850e" +Specify that the target processor is the V850E. The preprocessor +constant \fB_\|_v850e_\|_\fR will be defined if this option is used. +.Sp +If neither \fB\-mv850\fR nor \fB\-mv850e\fR nor \fB\-mv850e1\fR +are defined then a default target processor will be chosen and the +relevant \fB_\|_v850*_\|_\fR preprocessor constant will be defined. +.Sp +The preprocessor constants \fB_\|_v850\fR and \fB_\|_v851_\|_\fR are always +defined, regardless of which processor variant is the target. +.IP "\fB\-mdisable\-callt\fR" 4 +.IX Item "-mdisable-callt" +This option will suppress generation of the \s-1CALLT\s0 instruction for the +v850e and v850e1 flavors of the v850 architecture. The default is +\&\fB\-mno\-disable\-callt\fR which allows the \s-1CALLT\s0 instruction to be used. .PP -.I "\s-1ARC\s0 Options" +\fI\s-1ARC\s0 Options\fR .IX Subsection "ARC Options" .PP These options are defined for \s-1ARC\s0 implementations: -.Ip "\fB\-EL\fR" 4 +.IP "\fB\-EL\fR" 4 .IX Item "-EL" Compile code for little endian mode. This is the default. -.Ip "\fB\-EB\fR" 4 +.IP "\fB\-EB\fR" 4 .IX Item "-EB" Compile code for big endian mode. -.Ip "\fB\-mmangle-cpu\fR" 4 +.IP "\fB\-mmangle\-cpu\fR" 4 .IX Item "-mmangle-cpu" Prepend the name of the cpu to all public symbol names. In multiple-processor systems, there are many \s-1ARC\s0 variants with different @@ -7962,64 +9060,64 @@ instruction and register set characteristics. This flag prevents code compiled for one cpu to be linked with code compiled for another. No facility exists for handling variants that are ``almost identical''. This is an all or nothing option. -.Ip "\fB\-mcpu=\fR\fIcpu\fR" 4 +.IP "\fB\-mcpu=\fR\fIcpu\fR" 4 .IX Item "-mcpu=cpu" Compile code for \s-1ARC\s0 variant \fIcpu\fR. Which variants are supported depend on the configuration. All variants support \fB\-mcpu=base\fR, this is the default. -.Ip "\fB\-mtext=\fR\fItext-section\fR" 4 +.IP "\fB\-mtext=\fR\fItext-section\fR" 4 .IX Item "-mtext=text-section" .PD 0 -.Ip "\fB\-mdata=\fR\fIdata-section\fR" 4 +.IP "\fB\-mdata=\fR\fIdata-section\fR" 4 .IX Item "-mdata=data-section" -.Ip "\fB\-mrodata=\fR\fIreadonly-data-section\fR" 4 +.IP "\fB\-mrodata=\fR\fIreadonly-data-section\fR" 4 .IX Item "-mrodata=readonly-data-section" .PD Put functions, data, and readonly data in \fItext-section\fR, \&\fIdata-section\fR, and \fIreadonly-data-section\fR respectively by default. This can be overridden with the \f(CW\*(C`section\*(C'\fR attribute. .PP -.I "\s-1NS32K\s0 Options" +\fI\s-1NS32K\s0 Options\fR .IX Subsection "NS32K Options" .PP These are the \fB\-m\fR options defined for the 32000 series. The default values for these options depends on which style of 32000 was selected when the compiler was configured; the defaults for the most common choices are given below. -.Ip "\fB\-m32032\fR" 4 +.IP "\fB\-m32032\fR" 4 .IX Item "-m32032" .PD 0 -.Ip "\fB\-m32032\fR" 4 +.IP "\fB\-m32032\fR" 4 .IX Item "-m32032" .PD Generate output for a 32032. This is the default when the compiler is configured for 32032 and 32016 based systems. -.Ip "\fB\-m32332\fR" 4 +.IP "\fB\-m32332\fR" 4 .IX Item "-m32332" .PD 0 -.Ip "\fB\-m32332\fR" 4 +.IP "\fB\-m32332\fR" 4 .IX Item "-m32332" .PD Generate output for a 32332. This is the default when the compiler is configured for 32332\-based systems. -.Ip "\fB\-m32532\fR" 4 +.IP "\fB\-m32532\fR" 4 .IX Item "-m32532" .PD 0 -.Ip "\fB\-m32532\fR" 4 +.IP "\fB\-m32532\fR" 4 .IX Item "-m32532" .PD Generate output for a 32532. This is the default when the compiler is configured for 32532\-based systems. -.Ip "\fB\-m32081\fR" 4 +.IP "\fB\-m32081\fR" 4 .IX Item "-m32081" Generate output containing 32081 instructions for floating point. This is the default for all systems. -.Ip "\fB\-m32381\fR" 4 +.IP "\fB\-m32381\fR" 4 .IX Item "-m32381" Generate output containing 32381 instructions for floating point. This also implies \fB\-m32081\fR. The 32381 is only compatible with the 32332 and 32532 cpus. This is the default for the pc532\-netbsd configuration. -.Ip "\fB\-mmulti-add\fR" 4 +.IP "\fB\-mmulti\-add\fR" 4 .IX Item "-mmulti-add" Try and generate multiply-add floating point instructions \f(CW\*(C`polyF\*(C'\fR and \f(CW\*(C`dotF\*(C'\fR. This option is only available if the \fB\-m32381\fR @@ -8027,23 +9125,33 @@ option is in effect. Using these instructions requires changes to register allocation which generally has a negative impact on performance. This option should only be enabled when compiling code particularly likely to make heavy use of multiply-add instructions. -.Ip "\fB\-mnomulti-add\fR" 4 +.IP "\fB\-mnomulti\-add\fR" 4 .IX Item "-mnomulti-add" Do not try and generate multiply-add floating point instructions \&\f(CW\*(C`polyF\*(C'\fR and \f(CW\*(C`dotF\*(C'\fR. This is the default on all platforms. -.Ip "\fB\-msoft-float\fR" 4 +.IP "\fB\-msoft\-float\fR" 4 .IX Item "-msoft-float" Generate output containing library calls for floating point. \&\fBWarning:\fR the requisite libraries may not be available. -.Ip "\fB\-mnobitfield\fR" 4 +.IP "\fB\-mieee\-compare\fR" 4 +.IX Item "-mieee-compare" +.PD 0 +.IP "\fB\-mno\-ieee\-compare\fR" 4 +.IX Item "-mno-ieee-compare" +.PD +Control whether or not the compiler uses \s-1IEEE\s0 floating point +comparisons. These handle correctly the case where the result of a +comparison is unordered. +\&\fBWarning:\fR the requisite kernel support may not be available. +.IP "\fB\-mnobitfield\fR" 4 .IX Item "-mnobitfield" Do not use the bit-field instructions. On some machines it is faster to use shifting and masking operations. This is the default for the pc532. -.Ip "\fB\-mbitfield\fR" 4 +.IP "\fB\-mbitfield\fR" 4 .IX Item "-mbitfield" Do use the bit-field instructions. This is the default for all platforms except the pc532. -.Ip "\fB\-mrtd\fR" 4 +.IP "\fB\-mrtd\fR" 4 .IX Item "-mrtd" Use a different function-calling convention, in which functions that take a fixed number of arguments return pop their @@ -8063,7 +9171,7 @@ function with too many arguments. (Normally, extra arguments are harmlessly ignored.) .Sp This option takes its name from the 680x0 \f(CW\*(C`rtd\*(C'\fR instruction. -.Ip "\fB\-mregparam\fR" 4 +.IP "\fB\-mregparam\fR" 4 .IX Item "-mregparam" Use a different function-calling convention where the first two arguments are passed in registers. @@ -8071,36 +9179,36 @@ are passed in registers. This calling convention is incompatible with the one normally used on Unix, so you cannot use it if you need to call libraries compiled with the Unix compiler. -.Ip "\fB\-mnoregparam\fR" 4 +.IP "\fB\-mnoregparam\fR" 4 .IX Item "-mnoregparam" Do not pass any arguments in registers. This is the default for all targets. -.Ip "\fB\-msb\fR" 4 +.IP "\fB\-msb\fR" 4 .IX Item "-msb" It is \s-1OK\s0 to use the sb as an index register which is always loaded with zero. This is the default for the pc532\-netbsd target. -.Ip "\fB\-mnosb\fR" 4 +.IP "\fB\-mnosb\fR" 4 .IX Item "-mnosb" The sb register is not available for use or has not been initialized to zero by the run time system. This is the default for all targets except the pc532\-netbsd. It is also implied whenever \fB\-mhimem\fR or \&\fB\-fpic\fR is set. -.Ip "\fB\-mhimem\fR" 4 +.IP "\fB\-mhimem\fR" 4 .IX Item "-mhimem" Many ns32000 series addressing modes use displacements of up to 512MB. If an address is above 512MB then displacements from zero can not be used. This option causes code to be generated which can be loaded above 512MB. This may be useful for operating systems or \s-1ROM\s0 code. -.Ip "\fB\-mnohimem\fR" 4 +.IP "\fB\-mnohimem\fR" 4 .IX Item "-mnohimem" Assume code will be loaded in the first 512MB of virtual address space. This is the default for all platforms. .PP -.I "\s-1AVR\s0 Options" +\fI\s-1AVR\s0 Options\fR .IX Subsection "AVR Options" .PP These options are defined for \s-1AVR\s0 implementations: -.Ip "\fB\-mmcu=\fR\fImcu\fR" 4 +.IP "\fB\-mmcu=\fR\fImcu\fR" 4 .IX Item "-mmcu=mcu" Specify \s-1ATMEL\s0 \s-1AVR\s0 instruction set or \s-1MCU\s0 type. .Sp @@ -8122,268 +9230,306 @@ memory space (\s-1MCU\s0 types: atmega8, atmega83, atmega85). Instruction set avr5 is for the enhanced \s-1AVR\s0 core with up to 128K program memory space (\s-1MCU\s0 types: atmega16, atmega161, atmega163, atmega32, atmega323, atmega64, atmega128, at43usb355, at94k). -.Ip "\fB\-msize\fR" 4 +.IP "\fB\-msize\fR" 4 .IX Item "-msize" Output instruction sizes to the asm file. -.Ip "\fB\-minit-stack=\fR\fIN\fR" 4 +.IP "\fB\-minit\-stack=\fR\fIN\fR" 4 .IX Item "-minit-stack=N" Specify the initial stack address, which may be a symbol or numeric value, \&\fB_\|_stack\fR is the default. -.Ip "\fB\-mno-interrupts\fR" 4 +.IP "\fB\-mno\-interrupts\fR" 4 .IX Item "-mno-interrupts" Generated code is not compatible with hardware interrupts. Code size will be smaller. -.Ip "\fB\-mcall-prologues\fR" 4 +.IP "\fB\-mcall\-prologues\fR" 4 .IX Item "-mcall-prologues" Functions prologues/epilogues expanded as call to appropriate subroutines. Code size will be smaller. -.Ip "\fB\-mno-tablejump\fR" 4 +.IP "\fB\-mno\-tablejump\fR" 4 .IX Item "-mno-tablejump" Do not generate tablejump insns which sometimes increase code size. -.Ip "\fB\-mtiny-stack\fR" 4 +.IP "\fB\-mtiny\-stack\fR" 4 .IX Item "-mtiny-stack" Change only the low 8 bits of the stack pointer. .PP -.I "MCore Options" +\fIMCore Options\fR .IX Subsection "MCore Options" .PP These are the \fB\-m\fR options defined for the Motorola M*Core processors. -.Ip "\fB\-mhardlit\fR" 4 +.IP "\fB\-mhardlit\fR" 4 .IX Item "-mhardlit" .PD 0 -.Ip "\fB\-mhardlit\fR" 4 -.IX Item "-mhardlit" -.Ip "\fB\-mno-hardlit\fR" 4 +.IP "\fB\-mno\-hardlit\fR" 4 .IX Item "-mno-hardlit" .PD Inline constants into the code stream if it can be done in two instructions or less. -.Ip "\fB\-mdiv\fR" 4 +.IP "\fB\-mdiv\fR" 4 .IX Item "-mdiv" .PD 0 -.Ip "\fB\-mdiv\fR" 4 -.IX Item "-mdiv" -.Ip "\fB\-mno-div\fR" 4 +.IP "\fB\-mno\-div\fR" 4 .IX Item "-mno-div" .PD Use the divide instruction. (Enabled by default). -.Ip "\fB\-mrelax-immediate\fR" 4 +.IP "\fB\-mrelax\-immediate\fR" 4 .IX Item "-mrelax-immediate" .PD 0 -.Ip "\fB\-mrelax-immediate\fR" 4 -.IX Item "-mrelax-immediate" -.Ip "\fB\-mno-relax-immediate\fR" 4 +.IP "\fB\-mno\-relax\-immediate\fR" 4 .IX Item "-mno-relax-immediate" .PD Allow arbitrary sized immediates in bit operations. -.Ip "\fB\-mwide-bitfields\fR" 4 +.IP "\fB\-mwide\-bitfields\fR" 4 .IX Item "-mwide-bitfields" .PD 0 -.Ip "\fB\-mwide-bitfields\fR" 4 -.IX Item "-mwide-bitfields" -.Ip "\fB\-mno-wide-bitfields\fR" 4 +.IP "\fB\-mno\-wide\-bitfields\fR" 4 .IX Item "-mno-wide-bitfields" .PD -Always treat bit-fields as int-sized. -.Ip "\fB\-m4byte-functions\fR" 4 +Always treat bit-fields as int\-sized. +.IP "\fB\-m4byte\-functions\fR" 4 .IX Item "-m4byte-functions" .PD 0 -.Ip "\fB\-m4byte-functions\fR" 4 -.IX Item "-m4byte-functions" -.Ip "\fB\-mno-4byte-functions\fR" 4 +.IP "\fB\-mno\-4byte\-functions\fR" 4 .IX Item "-mno-4byte-functions" .PD Force all functions to be aligned to a four byte boundary. -.Ip "\fB\-mcallgraph-data\fR" 4 +.IP "\fB\-mcallgraph\-data\fR" 4 .IX Item "-mcallgraph-data" .PD 0 -.Ip "\fB\-mcallgraph-data\fR" 4 -.IX Item "-mcallgraph-data" -.Ip "\fB\-mno-callgraph-data\fR" 4 +.IP "\fB\-mno\-callgraph\-data\fR" 4 .IX Item "-mno-callgraph-data" .PD Emit callgraph information. -.Ip "\fB\-mslow-bytes\fR" 4 +.IP "\fB\-mslow\-bytes\fR" 4 .IX Item "-mslow-bytes" .PD 0 -.Ip "\fB\-mslow-bytes\fR" 4 -.IX Item "-mslow-bytes" -.Ip "\fB\-mno-slow-bytes\fR" 4 +.IP "\fB\-mno\-slow\-bytes\fR" 4 .IX Item "-mno-slow-bytes" .PD Prefer word access when reading byte quantities. -.Ip "\fB\-mlittle-endian\fR" 4 +.IP "\fB\-mlittle\-endian\fR" 4 .IX Item "-mlittle-endian" .PD 0 -.Ip "\fB\-mlittle-endian\fR" 4 -.IX Item "-mlittle-endian" -.Ip "\fB\-mbig-endian\fR" 4 +.IP "\fB\-mbig\-endian\fR" 4 .IX Item "-mbig-endian" .PD Generate code for a little endian target. -.Ip "\fB\-m210\fR" 4 +.IP "\fB\-m210\fR" 4 .IX Item "-m210" .PD 0 -.Ip "\fB\-m210\fR" 4 -.IX Item "-m210" -.Ip "\fB\-m340\fR" 4 +.IP "\fB\-m340\fR" 4 .IX Item "-m340" .PD Generate code for the 210 processor. .PP -.I "\s-1IA-64\s0 Options" +\fI\s-1IA\-64\s0 Options\fR .IX Subsection "IA-64 Options" .PP -These are the \fB\-m\fR options defined for the Intel \s-1IA-64\s0 architecture. -.Ip "\fB\-mbig-endian\fR" 4 +These are the \fB\-m\fR options defined for the Intel \s-1IA\-64\s0 architecture. +.IP "\fB\-mbig\-endian\fR" 4 .IX Item "-mbig-endian" -Generate code for a big endian target. This is the default for \s-1HPUX\s0. -.Ip "\fB\-mlittle-endian\fR" 4 +Generate code for a big endian target. This is the default for \s-1HP\-UX\s0. +.IP "\fB\-mlittle\-endian\fR" 4 .IX Item "-mlittle-endian" Generate code for a little endian target. This is the default for \s-1AIX5\s0 -and Linux. -.Ip "\fB\-mgnu-as\fR" 4 +and GNU/Linux. +.IP "\fB\-mgnu\-as\fR" 4 .IX Item "-mgnu-as" .PD 0 -.Ip "\fB\-mno-gnu-as\fR" 4 +.IP "\fB\-mno\-gnu\-as\fR" 4 .IX Item "-mno-gnu-as" .PD Generate (or don't) code for the \s-1GNU\s0 assembler. This is the default. -.Ip "\fB\-mgnu-ld\fR" 4 +.IP "\fB\-mgnu\-ld\fR" 4 .IX Item "-mgnu-ld" .PD 0 -.Ip "\fB\-mno-gnu-ld\fR" 4 +.IP "\fB\-mno\-gnu\-ld\fR" 4 .IX Item "-mno-gnu-ld" .PD Generate (or don't) code for the \s-1GNU\s0 linker. This is the default. -.Ip "\fB\-mno-pic\fR" 4 +.IP "\fB\-mno\-pic\fR" 4 .IX Item "-mno-pic" Generate code that does not use a global pointer register. The result -is not position independent code, and violates the \s-1IA-64\s0 \s-1ABI\s0. -.Ip "\fB\-mvolatile-asm-stop\fR" 4 +is not position independent code, and violates the \s-1IA\-64\s0 \s-1ABI\s0. +.IP "\fB\-mvolatile\-asm\-stop\fR" 4 .IX Item "-mvolatile-asm-stop" .PD 0 -.Ip "\fB\-mno-volatile-asm-stop\fR" 4 +.IP "\fB\-mno\-volatile\-asm\-stop\fR" 4 .IX Item "-mno-volatile-asm-stop" .PD Generate (or don't) a stop bit immediately before and after volatile asm statements. -.Ip "\fB\-mb-step\fR" 4 +.IP "\fB\-mb\-step\fR" 4 .IX Item "-mb-step" Generate code that works around Itanium B step errata. -.Ip "\fB\-mregister-names\fR" 4 +.IP "\fB\-mregister\-names\fR" 4 .IX Item "-mregister-names" .PD 0 -.Ip "\fB\-mno-register-names\fR" 4 +.IP "\fB\-mno\-register\-names\fR" 4 .IX Item "-mno-register-names" .PD Generate (or don't) \fBin\fR, \fBloc\fR, and \fBout\fR register names for the stacked registers. This may make assembler output more readable. -.Ip "\fB\-mno-sdata\fR" 4 +.IP "\fB\-mno\-sdata\fR" 4 .IX Item "-mno-sdata" .PD 0 -.Ip "\fB\-msdata\fR" 4 +.IP "\fB\-msdata\fR" 4 .IX Item "-msdata" .PD Disable (or enable) optimizations that use the small data section. This may be useful for working around optimizer bugs. -.Ip "\fB\-mconstant-gp\fR" 4 +.IP "\fB\-mconstant\-gp\fR" 4 .IX Item "-mconstant-gp" Generate code that uses a single constant global pointer value. This is useful when compiling kernel code. -.Ip "\fB\-mauto-pic\fR" 4 +.IP "\fB\-mauto\-pic\fR" 4 .IX Item "-mauto-pic" -Generate code that is self-relocatable. This implies \fB\-mconstant-gp\fR. +Generate code that is self\-relocatable. This implies \fB\-mconstant\-gp\fR. This is useful when compiling firmware code. -.Ip "\fB\-minline-divide-min-latency\fR" 4 -.IX Item "-minline-divide-min-latency" -Generate code for inline divides using the minimum latency algorithm. -.Ip "\fB\-minline-divide-max-throughput\fR" 4 -.IX Item "-minline-divide-max-throughput" -Generate code for inline divides using the maximum throughput algorithm. -.Ip "\fB\-mno-dwarf2\-asm\fR" 4 +.IP "\fB\-minline\-float\-divide\-min\-latency\fR" 4 +.IX Item "-minline-float-divide-min-latency" +Generate code for inline divides of floating point values +using the minimum latency algorithm. +.IP "\fB\-minline\-float\-divide\-max\-throughput\fR" 4 +.IX Item "-minline-float-divide-max-throughput" +Generate code for inline divides of floating point values +using the maximum throughput algorithm. +.IP "\fB\-minline\-int\-divide\-min\-latency\fR" 4 +.IX Item "-minline-int-divide-min-latency" +Generate code for inline divides of integer values +using the minimum latency algorithm. +.IP "\fB\-minline\-int\-divide\-max\-throughput\fR" 4 +.IX Item "-minline-int-divide-max-throughput" +Generate code for inline divides of integer values +using the maximum throughput algorithm. +.IP "\fB\-minline\-sqrt\-min\-latency\fR" 4 +.IX Item "-minline-sqrt-min-latency" +Generate code for inline square roots +using the minimum latency algorithm. +.IP "\fB\-minline\-sqrt\-max\-throughput\fR" 4 +.IX Item "-minline-sqrt-max-throughput" +Generate code for inline square roots +using the maximum throughput algorithm. +.IP "\fB\-mno\-dwarf2\-asm\fR" 4 .IX Item "-mno-dwarf2-asm" .PD 0 -.Ip "\fB\-mdwarf2\-asm\fR" 4 +.IP "\fB\-mdwarf2\-asm\fR" 4 .IX Item "-mdwarf2-asm" .PD Don't (or do) generate assembler code for the \s-1DWARF2\s0 line number debugging info. This may be useful when not using the \s-1GNU\s0 assembler. -.Ip "\fB\-mfixed-range=\fR\fIregister-range\fR" 4 +.IP "\fB\-mearly\-stop\-bits\fR" 4 +.IX Item "-mearly-stop-bits" +.PD 0 +.IP "\fB\-mno\-early\-stop\-bits\fR" 4 +.IX Item "-mno-early-stop-bits" +.PD +Allow stop bits to be placed earlier than immediately preceding the +instruction that triggered the stop bit. This can improve instruction +scheduling, but does not always do so. +.IP "\fB\-mfixed\-range=\fR\fIregister-range\fR" 4 .IX Item "-mfixed-range=register-range" Generate code treating the given register range as fixed registers. A fixed register is one that the register allocator can not use. This is useful when compiling kernel code. A register range is specified as two registers separated by a dash. Multiple register ranges can be specified separated by a comma. +.IP "\fB\-mtls\-size=\fR\fItls-size\fR" 4 +.IX Item "-mtls-size=tls-size" +Specify bit size of immediate \s-1TLS\s0 offsets. Valid values are 14, 22, and +64. +.IP "\fB\-mtune=\fR\fIcpu-type\fR" 4 +.IX Item "-mtune=cpu-type" +Tune the instruction scheduling for a particular \s-1CPU\s0, Valid values are +itanium, itanium1, merced, itanium2, and mckinley. +.IP "\fB\-mt\fR" 4 +.IX Item "-mt" +.PD 0 +.IP "\fB\-pthread\fR" 4 +.IX Item "-pthread" +.PD +Add support for multithreading using the \s-1POSIX\s0 threads library. This +option sets flags for both the preprocessor and linker. It does +not affect the thread safety of object code produced by the compiler or +that of libraries supplied with it. These are HP-UX specific flags. +.IP "\fB\-milp32\fR" 4 +.IX Item "-milp32" +.PD 0 +.IP "\fB\-mlp64\fR" 4 +.IX Item "-mlp64" +.PD +Generate code for a 32\-bit or 64\-bit environment. +The 32\-bit environment sets int, long and pointer to 32 bits. +The 64\-bit environment sets int to 32 bits and long and pointer +to 64 bits. These are HP-UX specific flags. .PP -.I "D30V Options" +\fID30V Options\fR .IX Subsection "D30V Options" .PP These \fB\-m\fR options are defined for D30V implementations: -.Ip "\fB\-mextmem\fR" 4 +.IP "\fB\-mextmem\fR" 4 .IX Item "-mextmem" Link the \fB.text\fR, \fB.data\fR, \fB.bss\fR, \fB.strings\fR, \&\fB.rodata\fR, \fB.rodata1\fR, \fB.data1\fR sections into external -memory, which starts at location \f(CW\*(C`0x80000000\*(C'\fR. -.Ip "\fB\-mextmemory\fR" 4 +memory, which starts at location \f(CW0x80000000\fR. +.IP "\fB\-mextmemory\fR" 4 .IX Item "-mextmemory" Same as the \fB\-mextmem\fR switch. -.Ip "\fB\-monchip\fR" 4 +.IP "\fB\-monchip\fR" 4 .IX Item "-monchip" Link the \fB.text\fR section into onchip text memory, which starts at -location \f(CW\*(C`0x0\*(C'\fR. Also link \fB.data\fR, \fB.bss\fR, +location \f(CW0x0\fR. Also link \fB.data\fR, \fB.bss\fR, \&\fB.strings\fR, \fB.rodata\fR, \fB.rodata1\fR, \fB.data1\fR sections -into onchip data memory, which starts at location \f(CW\*(C`0x20000000\*(C'\fR. -.Ip "\fB\-mno-asm-optimize\fR" 4 +into onchip data memory, which starts at location \f(CW0x20000000\fR. +.IP "\fB\-mno\-asm\-optimize\fR" 4 .IX Item "-mno-asm-optimize" .PD 0 -.Ip "\fB\-masm-optimize\fR" 4 +.IP "\fB\-masm\-optimize\fR" 4 .IX Item "-masm-optimize" .PD Disable (enable) passing \fB\-O\fR to the assembler when optimizing. The assembler uses the \fB\-O\fR option to automatically parallelize adjacent short instructions where possible. -.Ip "\fB\-mbranch-cost=\fR\fIn\fR" 4 +.IP "\fB\-mbranch\-cost=\fR\fIn\fR" 4 .IX Item "-mbranch-cost=n" Increase the internal costs of branches to \fIn\fR. Higher costs means that the compiler will issue more instructions to avoid doing a branch. The default is 2. -.Ip "\fB\-mcond-exec=\fR\fIn\fR" 4 +.IP "\fB\-mcond\-exec=\fR\fIn\fR" 4 .IX Item "-mcond-exec=n" Specify the maximum number of conditionally executed instructions that replace a branch. The default is 4. .PP -.I "S/390 and zSeries Options" +\fIS/390 and zSeries Options\fR .IX Subsection "S/390 and zSeries Options" .PP These are the \fB\-m\fR options defined for the S/390 and zSeries architecture. -.Ip "\fB\-mhard-float\fR" 4 +.IP "\fB\-mhard\-float\fR" 4 .IX Item "-mhard-float" .PD 0 -.Ip "\fB\-msoft-float\fR" 4 +.IP "\fB\-msoft\-float\fR" 4 .IX Item "-msoft-float" .PD Use (do not use) the hardware floating-point instructions and registers -for floating-point operations. When \fB\-msoft-float\fR is specified, +for floating-point operations. When \fB\-msoft\-float\fR is specified, functions in \fIlibgcc.a\fR will be used to perform floating-point -operations. When \fB\-mhard-float\fR is specified, the compiler +operations. When \fB\-mhard\-float\fR is specified, the compiler generates \s-1IEEE\s0 floating-point instructions. This is the default. -.Ip "\fB\-mbackchain\fR" 4 +.IP "\fB\-mbackchain\fR" 4 .IX Item "-mbackchain" .PD 0 -.Ip "\fB\-mno-backchain\fR" 4 +.IP "\fB\-mno\-backchain\fR" 4 .IX Item "-mno-backchain" .PD Generate (or do not generate) code which maintains an explicit backchain within the stack frame that points to the caller's frame. -This is currently needed to allow debugging. The default is to -generate the backchain. -.Ip "\fB\-msmall-exec\fR" 4 +This may be needed to allow debugging using tools that do not understand +\&\s-1DWARF\-2\s0 call frame information. The default is not to generate the +backchain. +.IP "\fB\-msmall\-exec\fR" 4 .IX Item "-msmall-exec" .PD 0 -.Ip "\fB\-mno-small-exec\fR" 4 +.IP "\fB\-mno\-small\-exec\fR" 4 .IX Item "-mno-small-exec" .PD Generate (or do not generate) code using the \f(CW\*(C`bras\*(C'\fR instruction @@ -8391,236 +9537,281 @@ to do subroutine calls. This only works reliably if the total executable size does not exceed 64k. The default is to use the \f(CW\*(C`basr\*(C'\fR instruction instead, which does not have this limitation. -.Ip "\fB\-m64\fR" 4 +.IP "\fB\-m64\fR" 4 .IX Item "-m64" .PD 0 -.Ip "\fB\-m31\fR" 4 +.IP "\fB\-m31\fR" 4 .IX Item "-m31" .PD When \fB\-m31\fR is specified, generate code compliant to the -Linux for S/390 \s-1ABI\s0. When \fB\-m64\fR is specified, generate -code compliant to the Linux for zSeries \s-1ABI\s0. This allows \s-1GCC\s0 in +GNU/Linux for S/390 \s-1ABI\s0. When \fB\-m64\fR is specified, generate +code compliant to the GNU/Linux for zSeries \s-1ABI\s0. This allows \s-1GCC\s0 in particular to generate 64\-bit instructions. For the \fBs390\fR targets, the default is \fB\-m31\fR, while the \fBs390x\fR targets default to \fB\-m64\fR. -.Ip "\fB\-mmvcle\fR" 4 +.IP "\fB\-mzarch\fR" 4 +.IX Item "-mzarch" +.PD 0 +.IP "\fB\-mesa\fR" 4 +.IX Item "-mesa" +.PD +When \fB\-mzarch\fR is specified, generate code using the +instructions available on z/Architecture. +When \fB\-mesa\fR is specified, generate code using the +instructions available on \s-1ESA/390\s0. Note that \fB\-mesa\fR is +not possible with \fB\-m64\fR. +When generating code compliant to the GNU/Linux for S/390 \s-1ABI\s0, +the default is \fB\-mesa\fR. When generating code compliant +to the GNU/Linux for zSeries \s-1ABI\s0, the default is \fB\-mzarch\fR. +.IP "\fB\-mmvcle\fR" 4 .IX Item "-mmvcle" .PD 0 -.Ip "\fB\-mno-mvcle\fR" 4 +.IP "\fB\-mno\-mvcle\fR" 4 .IX Item "-mno-mvcle" .PD Generate (or do not generate) code using the \f(CW\*(C`mvcle\*(C'\fR instruction -to perform block moves. When \fB\-mno-mvcle\fR is specifed, +to perform block moves. When \fB\-mno\-mvcle\fR is specified, use a \f(CW\*(C`mvc\*(C'\fR loop instead. This is the default. -.Ip "\fB\-mdebug\fR" 4 +.IP "\fB\-mdebug\fR" 4 .IX Item "-mdebug" .PD 0 -.Ip "\fB\-mno-debug\fR" 4 +.IP "\fB\-mno\-debug\fR" 4 .IX Item "-mno-debug" .PD Print (or do not print) additional debug information when compiling. The default is to not print debug information. +.IP "\fB\-march=\fR\fIcpu-type\fR" 4 +.IX Item "-march=cpu-type" +Generate code that will run on \fIcpu-type\fR, which is the name of a system +representing a certain processor type. Possible values for +\&\fIcpu-type\fR are \fBg5\fR, \fBg6\fR, \fBz900\fR, and \fBz990\fR. +When generating code using the instructions available on z/Architecture, +the default is \fB\-march=z900\fR. Otherwise, the default is +\&\fB\-march=g5\fR. +.IP "\fB\-mtune=\fR\fIcpu-type\fR" 4 +.IX Item "-mtune=cpu-type" +Tune to \fIcpu-type\fR everything applicable about the generated code, +except for the \s-1ABI\s0 and the set of available instructions. +The list of \fIcpu-type\fR values is the same as for \fB\-march\fR. +The default is the value used for \fB\-march\fR. +.IP "\fB\-mfused\-madd\fR" 4 +.IX Item "-mfused-madd" +.PD 0 +.IP "\fB\-mno\-fused\-madd\fR" 4 +.IX Item "-mno-fused-madd" +.PD +Generate code that uses (does not use) the floating point multiply and +accumulate instructions. These instructions are generated by default if +hardware floating point is used. .PP -.I "\s-1CRIS\s0 Options" +\fI\s-1CRIS\s0 Options\fR .IX Subsection "CRIS Options" .PP These options are defined specifically for the \s-1CRIS\s0 ports. -.Ip "\fB\-march=\fR\fIarchitecture-type\fR" 4 +.IP "\fB\-march=\fR\fIarchitecture-type\fR" 4 .IX Item "-march=architecture-type" .PD 0 -.Ip "\fB\-mcpu=\fR\fIarchitecture-type\fR" 4 +.IP "\fB\-mcpu=\fR\fIarchitecture-type\fR" 4 .IX Item "-mcpu=architecture-type" .PD Generate code for the specified architecture. The choices for \&\fIarchitecture-type\fR are \fBv3\fR, \fBv8\fR and \fBv10\fR for respectively \s-1ETRAX\s0\ 4, \s-1ETRAX\s0\ 100, and \s-1ETRAX\s0\ 100\ \s-1LX\s0. -Default is \fBv0\fR except for cris-axis-linux-gnu, where the default is +Default is \fBv0\fR except for cris\-axis\-linux\-gnu, where the default is \&\fBv10\fR. -.Ip "\fB\-mtune=\fR\fIarchitecture-type\fR" 4 +.IP "\fB\-mtune=\fR\fIarchitecture-type\fR" 4 .IX Item "-mtune=architecture-type" Tune to \fIarchitecture-type\fR everything applicable about the generated code, except for the \s-1ABI\s0 and the set of available instructions. The choices for \fIarchitecture-type\fR are the same as for \&\fB\-march=\fR\fIarchitecture-type\fR. -.Ip "\fB\-mmax-stack-frame=\fR\fIn\fR" 4 +.IP "\fB\-mmax\-stack\-frame=\fR\fIn\fR" 4 .IX Item "-mmax-stack-frame=n" Warn when the stack frame of a function exceeds \fIn\fR bytes. -.Ip "\fB\-melinux-stacksize=\fR\fIn\fR" 4 +.IP "\fB\-melinux\-stacksize=\fR\fIn\fR" 4 .IX Item "-melinux-stacksize=n" Only available with the \fBcris-axis-aout\fR target. Arranges for indications in the program to the kernel loader that the stack of the program should be set to \fIn\fR bytes. -.Ip "\fB\-metrax4\fR" 4 +.IP "\fB\-metrax4\fR" 4 .IX Item "-metrax4" .PD 0 -.Ip "\fB\-metrax100\fR" 4 +.IP "\fB\-metrax100\fR" 4 .IX Item "-metrax100" .PD The options \fB\-metrax4\fR and \fB\-metrax100\fR are synonyms for \&\fB\-march=v3\fR and \fB\-march=v8\fR respectively. -.Ip "\fB\-mpdebug\fR" 4 +.IP "\fB\-mmul\-bug\-workaround\fR" 4 +.IX Item "-mmul-bug-workaround" +.PD 0 +.IP "\fB\-mno\-mul\-bug\-workaround\fR" 4 +.IX Item "-mno-mul-bug-workaround" +.PD +Work around a bug in the \f(CW\*(C`muls\*(C'\fR and \f(CW\*(C`mulu\*(C'\fR instructions for \s-1CPU\s0 +models where it applies. This option is active by default. +.IP "\fB\-mpdebug\fR" 4 .IX Item "-mpdebug" Enable CRIS-specific verbose debug-related information in the assembly code. This option also has the effect to turn off the \fB#NO_APP\fR formatted-code indicator to the assembler at the beginning of the assembly file. -.Ip "\fB\-mcc-init\fR" 4 +.IP "\fB\-mcc\-init\fR" 4 .IX Item "-mcc-init" Do not use condition-code results from previous instruction; always emit compare and test instructions before use of condition codes. -.Ip "\fB\-mno-side-effects\fR" 4 +.IP "\fB\-mno\-side\-effects\fR" 4 .IX Item "-mno-side-effects" Do not emit instructions with side-effects in addressing modes other than -post-increment. -.Ip "\fB\-mstack-align\fR" 4 +post\-increment. +.IP "\fB\-mstack\-align\fR" 4 .IX Item "-mstack-align" .PD 0 -.Ip "\fB\-mno-stack-align\fR" 4 +.IP "\fB\-mno\-stack\-align\fR" 4 .IX Item "-mno-stack-align" -.Ip "\fB\-mdata-align\fR" 4 +.IP "\fB\-mdata\-align\fR" 4 .IX Item "-mdata-align" -.Ip "\fB\-mno-data-align\fR" 4 +.IP "\fB\-mno\-data\-align\fR" 4 .IX Item "-mno-data-align" -.Ip "\fB\-mconst-align\fR" 4 +.IP "\fB\-mconst\-align\fR" 4 .IX Item "-mconst-align" -.Ip "\fB\-mno-const-align\fR" 4 +.IP "\fB\-mno\-const\-align\fR" 4 .IX Item "-mno-const-align" .PD -These options (no-options) arranges (eliminate arrangements) for the -stack-frame, individual data and constants to be aligned for the maximum +These options (no\-options) arranges (eliminate arrangements) for the +stack\-frame, individual data and constants to be aligned for the maximum single data access size for the chosen \s-1CPU\s0 model. The default is to arrange for 32\-bit alignment. \s-1ABI\s0 details such as structure layout are not affected by these options. -.Ip "\fB\-m32\-bit\fR" 4 +.IP "\fB\-m32\-bit\fR" 4 .IX Item "-m32-bit" .PD 0 -.Ip "\fB\-m16\-bit\fR" 4 +.IP "\fB\-m16\-bit\fR" 4 .IX Item "-m16-bit" -.Ip "\fB\-m8\-bit\fR" 4 +.IP "\fB\-m8\-bit\fR" 4 .IX Item "-m8-bit" .PD -Similar to the stack- data- and const-align options above, these options -arrange for stack-frame, writable data and constants to all be 32\-bit, +Similar to the stack\- data\- and const-align options above, these options +arrange for stack\-frame, writable data and constants to all be 32\-bit, 16\-bit or 8\-bit aligned. The default is 32\-bit alignment. -.Ip "\fB\-mno-prologue-epilogue\fR" 4 +.IP "\fB\-mno\-prologue\-epilogue\fR" 4 .IX Item "-mno-prologue-epilogue" .PD 0 -.Ip "\fB\-mprologue-epilogue\fR" 4 +.IP "\fB\-mprologue\-epilogue\fR" 4 .IX Item "-mprologue-epilogue" .PD -With \fB\-mno-prologue-epilogue\fR, the normal function prologue and +With \fB\-mno\-prologue\-epilogue\fR, the normal function prologue and epilogue that sets up the stack-frame are omitted and no return instructions or return sequences are generated in the code. Use this option only together with visual inspection of the compiled code: no warnings or errors are generated when call-saved registers must be saved, or storage for local variable needs to be allocated. -.Ip "\fB\-mno-gotplt\fR" 4 +.IP "\fB\-mno\-gotplt\fR" 4 .IX Item "-mno-gotplt" .PD 0 -.Ip "\fB\-mgotplt\fR" 4 +.IP "\fB\-mgotplt\fR" 4 .IX Item "-mgotplt" .PD With \fB\-fpic\fR and \fB\-fPIC\fR, don't generate (do generate) instruction sequences that load addresses for functions from the \s-1PLT\s0 part of the \s-1GOT\s0 rather than (traditional on other architectures) calls to the \&\s-1PLT\s0. The default is \fB\-mgotplt\fR. -.Ip "\fB\-maout\fR" 4 +.IP "\fB\-maout\fR" 4 .IX Item "-maout" Legacy no-op option only recognized with the cris-axis-aout target. -.Ip "\fB\-melf\fR" 4 +.IP "\fB\-melf\fR" 4 .IX Item "-melf" Legacy no-op option only recognized with the cris-axis-elf and cris-axis-linux-gnu targets. -.Ip "\fB\-melinux\fR" 4 +.IP "\fB\-melinux\fR" 4 .IX Item "-melinux" Only recognized with the cris-axis-aout target, where it selects a -GNU/linux-like multilib, include files and instruction set for +GNU/linux\-like multilib, include files and instruction set for \&\fB\-march=v8\fR. -.Ip "\fB\-mlinux\fR" 4 +.IP "\fB\-mlinux\fR" 4 .IX Item "-mlinux" Legacy no-op option only recognized with the cris-axis-linux-gnu target. -.Ip "\fB\-sim\fR" 4 +.IP "\fB\-sim\fR" 4 .IX Item "-sim" This option, recognized for the cris-axis-aout and cris-axis-elf arranges to link with input-output functions from a simulator library. Code, initialized data and zero-initialized data are allocated consecutively. -.Ip "\fB\-sim2\fR" 4 +.IP "\fB\-sim2\fR" 4 .IX Item "-sim2" Like \fB\-sim\fR, but pass linker options to locate initialized data at 0x40000000 and zero-initialized data at 0x80000000. .PP -.I "\s-1MMIX\s0 Options" +\fI\s-1MMIX\s0 Options\fR .IX Subsection "MMIX Options" .PP These options are defined for the \s-1MMIX:\s0 -.Ip "\fB\-mlibfuncs\fR" 4 +.IP "\fB\-mlibfuncs\fR" 4 .IX Item "-mlibfuncs" .PD 0 -.Ip "\fB\-mno-libfuncs\fR" 4 +.IP "\fB\-mno\-libfuncs\fR" 4 .IX Item "-mno-libfuncs" .PD Specify that intrinsic library functions are being compiled, passing all values in registers, no matter the size. -.Ip "\fB\-mepsilon\fR" 4 +.IP "\fB\-mepsilon\fR" 4 .IX Item "-mepsilon" .PD 0 -.Ip "\fB\-mno-epsilon\fR" 4 +.IP "\fB\-mno\-epsilon\fR" 4 .IX Item "-mno-epsilon" .PD Generate floating-point comparison instructions that compare with respect to the \f(CW\*(C`rE\*(C'\fR epsilon register. -.Ip "\fB\-mabi=mmixware\fR" 4 +.IP "\fB\-mabi=mmixware\fR" 4 .IX Item "-mabi=mmixware" .PD 0 -.Ip "\fB\-mabi=gnu\fR" 4 +.IP "\fB\-mabi=gnu\fR" 4 .IX Item "-mabi=gnu" .PD Generate code that passes function parameters and return values that (in -the called function) are seen as registers \f(CW\*(C`$0\*(C'\fR and up, as opposed to -the \s-1GNU\s0 \s-1ABI\s0 which uses global registers \f(CW\*(C`$231\*(C'\fR and up. -.Ip "\fB\-mzero-extend\fR" 4 +the called function) are seen as registers \f(CW$0\fR and up, as opposed to +the \s-1GNU\s0 \s-1ABI\s0 which uses global registers \f(CW$231\fR and up. +.IP "\fB\-mzero\-extend\fR" 4 .IX Item "-mzero-extend" .PD 0 -.Ip "\fB\-mno-zero-extend\fR" 4 +.IP "\fB\-mno\-zero\-extend\fR" 4 .IX Item "-mno-zero-extend" .PD When reading data from memory in sizes shorter than 64 bits, use (do not use) zero-extending load instructions by default, rather than sign-extending ones. -.Ip "\fB\-mknuthdiv\fR" 4 +.IP "\fB\-mknuthdiv\fR" 4 .IX Item "-mknuthdiv" .PD 0 -.Ip "\fB\-mno-knuthdiv\fR" 4 +.IP "\fB\-mno\-knuthdiv\fR" 4 .IX Item "-mno-knuthdiv" .PD Make the result of a division yielding a remainder have the same sign as -the divisor. With the default, \fB\-mno-knuthdiv\fR, the sign of the +the divisor. With the default, \fB\-mno\-knuthdiv\fR, the sign of the remainder follows the sign of the dividend. Both methods are arithmetically valid, the latter being almost exclusively used. -.Ip "\fB\-mtoplevel-symbols\fR" 4 +.IP "\fB\-mtoplevel\-symbols\fR" 4 .IX Item "-mtoplevel-symbols" .PD 0 -.Ip "\fB\-mno-toplevel-symbols\fR" 4 +.IP "\fB\-mno\-toplevel\-symbols\fR" 4 .IX Item "-mno-toplevel-symbols" .PD Prepend (do not prepend) a \fB:\fR to all global symbols, so the assembly code can be used with the \f(CW\*(C`PREFIX\*(C'\fR assembly directive. -.Ip "\fB\-melf\fR" 4 +.IP "\fB\-melf\fR" 4 .IX Item "-melf" Generate an executable in the \s-1ELF\s0 format, rather than the default \&\fBmmo\fR format used by the \fBmmix\fR simulator. -.Ip "\fB\-mbranch-predict\fR" 4 +.IP "\fB\-mbranch\-predict\fR" 4 .IX Item "-mbranch-predict" .PD 0 -.Ip "\fB\-mno-branch-predict\fR" 4 +.IP "\fB\-mno\-branch\-predict\fR" 4 .IX Item "-mno-branch-predict" .PD Use (do not use) the probable-branch instructions, when static branch prediction indicates a probable branch. -.Ip "\fB\-mbase-addresses\fR" 4 +.IP "\fB\-mbase\-addresses\fR" 4 .IX Item "-mbase-addresses" .PD 0 -.Ip "\fB\-mno-base-addresses\fR" 4 +.IP "\fB\-mno\-base\-addresses\fR" 4 .IX Item "-mno-base-addresses" .PD Generate (do not generate) code that uses \fIbase addresses\fR. Using a @@ -8630,215 +9821,284 @@ register is used for one or more base address requests within the range 0 to 255 from the value held in the register. The generally leads to short and fast code, but the number of different data items that can be addressed is limited. This means that a program that uses lots of static -data may require \fB\-mno-base-addresses\fR. +data may require \fB\-mno\-base\-addresses\fR. +.IP "\fB\-msingle\-exit\fR" 4 +.IX Item "-msingle-exit" +.PD 0 +.IP "\fB\-mno\-single\-exit\fR" 4 +.IX Item "-mno-single-exit" +.PD +Force (do not force) generated code to have a single exit point in each +function. .PP -.I "\s-1PDP-11\s0 Options" +\fI\s-1PDP\-11\s0 Options\fR .IX Subsection "PDP-11 Options" .PP -These options are defined for the \s-1PDP-11:\s0 -.Ip "\fB\-mfpu\fR" 4 +These options are defined for the \s-1PDP\-11:\s0 +.IP "\fB\-mfpu\fR" 4 .IX Item "-mfpu" Use hardware \s-1FPP\s0 floating point. This is the default. (\s-1FIS\s0 floating -point on the \s-1PDP-11/40\s0 is not supported.) -.Ip "\fB\-msoft-float\fR" 4 +point on the \s-1PDP\-11/40\s0 is not supported.) +.IP "\fB\-msoft\-float\fR" 4 .IX Item "-msoft-float" Do not use hardware floating point. -.Ip "\fB\-mac0\fR" 4 +.IP "\fB\-mac0\fR" 4 .IX Item "-mac0" Return floating-point results in ac0 (fr0 in Unix assembler syntax). -.Ip "\fB\-mno-ac0\fR" 4 +.IP "\fB\-mno\-ac0\fR" 4 .IX Item "-mno-ac0" Return floating-point results in memory. This is the default. -.Ip "\fB\-m40\fR" 4 +.IP "\fB\-m40\fR" 4 .IX Item "-m40" -Generate code for a \s-1PDP-11/40\s0. -.Ip "\fB\-m45\fR" 4 +Generate code for a \s-1PDP\-11/40\s0. +.IP "\fB\-m45\fR" 4 .IX Item "-m45" -Generate code for a \s-1PDP-11/45\s0. This is the default. -.Ip "\fB\-m10\fR" 4 +Generate code for a \s-1PDP\-11/45\s0. This is the default. +.IP "\fB\-m10\fR" 4 .IX Item "-m10" -Generate code for a \s-1PDP-11/10\s0. -.Ip "\fB\-mbcopy-builtin\fR" 4 +Generate code for a \s-1PDP\-11/10\s0. +.IP "\fB\-mbcopy\-builtin\fR" 4 .IX Item "-mbcopy-builtin" Use inline \f(CW\*(C`movstrhi\*(C'\fR patterns for copying memory. This is the default. -.Ip "\fB\-mbcopy\fR" 4 +.IP "\fB\-mbcopy\fR" 4 .IX Item "-mbcopy" Do not use inline \f(CW\*(C`movstrhi\*(C'\fR patterns for copying memory. -.Ip "\fB\-mint16\fR" 4 +.IP "\fB\-mint16\fR" 4 .IX Item "-mint16" .PD 0 -.Ip "\fB\-mno-int32\fR" 4 +.IP "\fB\-mno\-int32\fR" 4 .IX Item "-mno-int32" .PD Use 16\-bit \f(CW\*(C`int\*(C'\fR. This is the default. -.Ip "\fB\-mint32\fR" 4 +.IP "\fB\-mint32\fR" 4 .IX Item "-mint32" .PD 0 -.Ip "\fB\-mno-int16\fR" 4 +.IP "\fB\-mno\-int16\fR" 4 .IX Item "-mno-int16" .PD Use 32\-bit \f(CW\*(C`int\*(C'\fR. -.Ip "\fB\-mfloat64\fR" 4 +.IP "\fB\-mfloat64\fR" 4 .IX Item "-mfloat64" .PD 0 -.Ip "\fB\-mno-float32\fR" 4 +.IP "\fB\-mno\-float32\fR" 4 .IX Item "-mno-float32" .PD Use 64\-bit \f(CW\*(C`float\*(C'\fR. This is the default. -.Ip "\fB\-mfloat32\fR" 4 +.IP "\fB\-mfloat32\fR" 4 .IX Item "-mfloat32" .PD 0 -.Ip "\fB\-mno-float64\fR" 4 +.IP "\fB\-mno\-float64\fR" 4 .IX Item "-mno-float64" .PD Use 32\-bit \f(CW\*(C`float\*(C'\fR. -.Ip "\fB\-mabshi\fR" 4 +.IP "\fB\-mabshi\fR" 4 .IX Item "-mabshi" Use \f(CW\*(C`abshi2\*(C'\fR pattern. This is the default. -.Ip "\fB\-mno-abshi\fR" 4 +.IP "\fB\-mno\-abshi\fR" 4 .IX Item "-mno-abshi" Do not use \f(CW\*(C`abshi2\*(C'\fR pattern. -.Ip "\fB\-mbranch-expensive\fR" 4 +.IP "\fB\-mbranch\-expensive\fR" 4 .IX Item "-mbranch-expensive" Pretend that branches are expensive. This is for experimenting with code generation only. -.Ip "\fB\-mbranch-cheap\fR" 4 +.IP "\fB\-mbranch\-cheap\fR" 4 .IX Item "-mbranch-cheap" Do not pretend that branches are expensive. This is the default. -.Ip "\fB\-msplit\fR" 4 +.IP "\fB\-msplit\fR" 4 .IX Item "-msplit" Generate code for a system with split I&D. -.Ip "\fB\-mno-split\fR" 4 +.IP "\fB\-mno\-split\fR" 4 .IX Item "-mno-split" Generate code for a system without split I&D. This is the default. -.Ip "\fB\-munix-asm\fR" 4 +.IP "\fB\-munix\-asm\fR" 4 .IX Item "-munix-asm" Use Unix assembler syntax. This is the default when configured for \&\fBpdp11\-*\-bsd\fR. -.Ip "\fB\-mdec-asm\fR" 4 +.IP "\fB\-mdec\-asm\fR" 4 .IX Item "-mdec-asm" Use \s-1DEC\s0 assembler syntax. This is the default when configured for any -\&\s-1PDP-11\s0 target other than \fBpdp11\-*\-bsd\fR. +\&\s-1PDP\-11\s0 target other than \fBpdp11\-*\-bsd\fR. .PP -.I "Xstormy16 Options" +\fIXstormy16 Options\fR .IX Subsection "Xstormy16 Options" .PP These options are defined for Xstormy16: -.Ip "\fB\-msim\fR" 4 +.IP "\fB\-msim\fR" 4 .IX Item "-msim" Choose startup files and linker script suitable for the simulator. .PP -.I "Xtensa Options" -.IX Subsection "Xtensa Options" -.PP -The Xtensa architecture is designed to support many different -configurations. The compiler's default options can be set to match a -particular Xtensa configuration by copying a configuration file into the -\&\s-1GCC\s0 sources when building \s-1GCC\s0. The options below may be used to -override the default options. -.Ip "\fB\-mbig-endian\fR" 4 -.IX Item "-mbig-endian" -.PD 0 -.Ip "\fB\-mlittle-endian\fR" 4 -.IX Item "-mlittle-endian" -.PD -Specify big-endian or little-endian byte ordering for the target Xtensa -processor. -.Ip "\fB\-mdensity\fR" 4 -.IX Item "-mdensity" -.PD 0 -.Ip "\fB\-mno-density\fR" 4 -.IX Item "-mno-density" -.PD -Enable or disable use of the optional Xtensa code density instructions. -.Ip "\fB\-mmac16\fR" 4 -.IX Item "-mmac16" -.PD 0 -.Ip "\fB\-mno-mac16\fR" 4 -.IX Item "-mno-mac16" -.PD -Enable or disable use of the Xtensa \s-1MAC16\s0 option. When enabled, \s-1GCC\s0 -will generate \s-1MAC16\s0 instructions from standard C code, with the -limitation that it will use neither the \s-1MR\s0 register file nor any -instruction that operates on the \s-1MR\s0 registers. When this option is -disabled, \s-1GCC\s0 will translate 16\-bit multiply/accumulate operations to a -combination of core instructions and library calls, depending on whether -any other multiplier options are enabled. -.Ip "\fB\-mmul16\fR" 4 -.IX Item "-mmul16" -.PD 0 -.Ip "\fB\-mno-mul16\fR" 4 -.IX Item "-mno-mul16" -.PD -Enable or disable use of the 16\-bit integer multiplier option. When -enabled, the compiler will generate 16\-bit multiply instructions for -multiplications of 16 bits or smaller in standard C code. When this -option is disabled, the compiler will either use 32\-bit multiply or -\&\s-1MAC16\s0 instructions if they are available or generate library calls to -perform the multiply operations using shifts and adds. -.Ip "\fB\-mmul32\fR" 4 -.IX Item "-mmul32" -.PD 0 -.Ip "\fB\-mno-mul32\fR" 4 -.IX Item "-mno-mul32" -.PD -Enable or disable use of the 32\-bit integer multiplier option. When -enabled, the compiler will generate 32\-bit multiply instructions for -multiplications of 32 bits or smaller in standard C code. When this -option is disabled, the compiler will generate library calls to perform -the multiply operations using either shifts and adds or 16\-bit multiply -instructions if they are available. -.Ip "\fB\-mnsa\fR" 4 -.IX Item "-mnsa" -.PD 0 -.Ip "\fB\-mno-nsa\fR" 4 -.IX Item "-mno-nsa" -.PD -Enable or disable use of the optional normalization shift amount -(\f(CW\*(C`NSA\*(C'\fR) instructions to implement the built-in \f(CW\*(C`ffs\*(C'\fR function. -.Ip "\fB\-mminmax\fR" 4 -.IX Item "-mminmax" -.PD 0 -.Ip "\fB\-mno-minmax\fR" 4 -.IX Item "-mno-minmax" -.PD -Enable or disable use of the optional minimum and maximum value -instructions. -.Ip "\fB\-msext\fR" 4 -.IX Item "-msext" -.PD 0 -.Ip "\fB\-mno-sext\fR" 4 -.IX Item "-mno-sext" -.PD -Enable or disable use of the optional sign extend (\f(CW\*(C`SEXT\*(C'\fR) -instruction. -.Ip "\fB\-mbooleans\fR" 4 -.IX Item "-mbooleans" -.PD 0 -.Ip "\fB\-mno-booleans\fR" 4 -.IX Item "-mno-booleans" -.PD -Enable or disable support for the boolean register file used by Xtensa -coprocessors. This is not typically useful by itself but may be -required for other options that make use of the boolean registers (e.g., -the floating-point option). -.Ip "\fB\-mhard-float\fR" 4 +\fI\s-1FRV\s0 Options\fR +.IX Subsection "FRV Options" +.IP "\fB\-mgpr\-32\fR" 4 +.IX Item "-mgpr-32" +Only use the first 32 general purpose registers. +.IP "\fB\-mgpr\-64\fR" 4 +.IX Item "-mgpr-64" +Use all 64 general purpose registers. +.IP "\fB\-mfpr\-32\fR" 4 +.IX Item "-mfpr-32" +Use only the first 32 floating point registers. +.IP "\fB\-mfpr\-64\fR" 4 +.IX Item "-mfpr-64" +Use all 64 floating point registers +.IP "\fB\-mhard\-float\fR" 4 .IX Item "-mhard-float" -.PD 0 -.Ip "\fB\-msoft-float\fR" 4 +Use hardware instructions for floating point operations. +.IP "\fB\-msoft\-float\fR" 4 .IX Item "-msoft-float" -.PD -Enable or disable use of the floating-point option. When enabled, \s-1GCC\s0 -generates floating-point instructions for 32\-bit \f(CW\*(C`float\*(C'\fR -operations. When this option is disabled, \s-1GCC\s0 generates library calls -to emulate 32\-bit floating-point operations using integer instructions. -Regardless of this option, 64\-bit \f(CW\*(C`double\*(C'\fR operations are always -emulated with calls to library functions. -.Ip "\fB\-mfused-madd\fR" 4 +Use library routines for floating point operations. +.IP "\fB\-malloc\-cc\fR" 4 +.IX Item "-malloc-cc" +Dynamically allocate condition code registers. +.IP "\fB\-mfixed\-cc\fR" 4 +.IX Item "-mfixed-cc" +Do not try to dynamically allocate condition code registers, only +use \f(CW\*(C`icc0\*(C'\fR and \f(CW\*(C`fcc0\*(C'\fR. +.IP "\fB\-mdword\fR" 4 +.IX Item "-mdword" +Change \s-1ABI\s0 to use double word insns. +.IP "\fB\-mno\-dword\fR" 4 +.IX Item "-mno-dword" +Do not use double word instructions. +.IP "\fB\-mdouble\fR" 4 +.IX Item "-mdouble" +Use floating point double instructions. +.IP "\fB\-mno\-double\fR" 4 +.IX Item "-mno-double" +Do not use floating point double instructions. +.IP "\fB\-mmedia\fR" 4 +.IX Item "-mmedia" +Use media instructions. +.IP "\fB\-mno\-media\fR" 4 +.IX Item "-mno-media" +Do not use media instructions. +.IP "\fB\-mmuladd\fR" 4 +.IX Item "-mmuladd" +Use multiply and add/subtract instructions. +.IP "\fB\-mno\-muladd\fR" 4 +.IX Item "-mno-muladd" +Do not use multiply and add/subtract instructions. +.IP "\fB\-mlibrary\-pic\fR" 4 +.IX Item "-mlibrary-pic" +Enable \s-1PIC\s0 support for building libraries +.IP "\fB\-macc\-4\fR" 4 +.IX Item "-macc-4" +Use only the first four media accumulator registers. +.IP "\fB\-macc\-8\fR" 4 +.IX Item "-macc-8" +Use all eight media accumulator registers. +.IP "\fB\-mpack\fR" 4 +.IX Item "-mpack" +Pack \s-1VLIW\s0 instructions. +.IP "\fB\-mno\-pack\fR" 4 +.IX Item "-mno-pack" +Do not pack \s-1VLIW\s0 instructions. +.IP "\fB\-mno\-eflags\fR" 4 +.IX Item "-mno-eflags" +Do not mark \s-1ABI\s0 switches in e_flags. +.IP "\fB\-mcond\-move\fR" 4 +.IX Item "-mcond-move" +Enable the use of conditional-move instructions (default). +.Sp +This switch is mainly for debugging the compiler and will likely be removed +in a future version. +.IP "\fB\-mno\-cond\-move\fR" 4 +.IX Item "-mno-cond-move" +Disable the use of conditional-move instructions. +.Sp +This switch is mainly for debugging the compiler and will likely be removed +in a future version. +.IP "\fB\-mscc\fR" 4 +.IX Item "-mscc" +Enable the use of conditional set instructions (default). +.Sp +This switch is mainly for debugging the compiler and will likely be removed +in a future version. +.IP "\fB\-mno\-scc\fR" 4 +.IX Item "-mno-scc" +Disable the use of conditional set instructions. +.Sp +This switch is mainly for debugging the compiler and will likely be removed +in a future version. +.IP "\fB\-mcond\-exec\fR" 4 +.IX Item "-mcond-exec" +Enable the use of conditional execution (default). +.Sp +This switch is mainly for debugging the compiler and will likely be removed +in a future version. +.IP "\fB\-mno\-cond\-exec\fR" 4 +.IX Item "-mno-cond-exec" +Disable the use of conditional execution. +.Sp +This switch is mainly for debugging the compiler and will likely be removed +in a future version. +.IP "\fB\-mvliw\-branch\fR" 4 +.IX Item "-mvliw-branch" +Run a pass to pack branches into \s-1VLIW\s0 instructions (default). +.Sp +This switch is mainly for debugging the compiler and will likely be removed +in a future version. +.IP "\fB\-mno\-vliw\-branch\fR" 4 +.IX Item "-mno-vliw-branch" +Do not run a pass to pack branches into \s-1VLIW\s0 instructions. +.Sp +This switch is mainly for debugging the compiler and will likely be removed +in a future version. +.IP "\fB\-mmulti\-cond\-exec\fR" 4 +.IX Item "-mmulti-cond-exec" +Enable optimization of \f(CW\*(C`&&\*(C'\fR and \f(CW\*(C`||\*(C'\fR in conditional execution +(default). +.Sp +This switch is mainly for debugging the compiler and will likely be removed +in a future version. +.IP "\fB\-mno\-multi\-cond\-exec\fR" 4 +.IX Item "-mno-multi-cond-exec" +Disable optimization of \f(CW\*(C`&&\*(C'\fR and \f(CW\*(C`||\*(C'\fR in conditional execution. +.Sp +This switch is mainly for debugging the compiler and will likely be removed +in a future version. +.IP "\fB\-mnested\-cond\-exec\fR" 4 +.IX Item "-mnested-cond-exec" +Enable nested conditional execution optimizations (default). +.Sp +This switch is mainly for debugging the compiler and will likely be removed +in a future version. +.IP "\fB\-mno\-nested\-cond\-exec\fR" 4 +.IX Item "-mno-nested-cond-exec" +Disable nested conditional execution optimizations. +.Sp +This switch is mainly for debugging the compiler and will likely be removed +in a future version. +.IP "\fB\-mtomcat\-stats\fR" 4 +.IX Item "-mtomcat-stats" +Cause gas to print out tomcat statistics. +.IP "\fB\-mcpu=\fR\fIcpu\fR" 4 +.IX Item "-mcpu=cpu" +Select the processor type for which to generate code. Possible values are +\&\fBsimple\fR, \fBtomcat\fR, \fBfr500\fR, \fBfr400\fR, \fBfr300\fR, +\&\fBfrv\fR. +.PP +\fIXtensa Options\fR +.IX Subsection "Xtensa Options" +.PP +These options are supported for Xtensa targets: +.IP "\fB\-mconst16\fR" 4 +.IX Item "-mconst16" +.PD 0 +.IP "\fB\-mno\-const16\fR" 4 +.IX Item "-mno-const16" +.PD +Enable or disable use of \f(CW\*(C`CONST16\*(C'\fR instructions for loading +constant values. The \f(CW\*(C`CONST16\*(C'\fR instruction is currently not a +standard option from Tensilica. When enabled, \f(CW\*(C`CONST16\*(C'\fR +instructions are always used in place of the standard \f(CW\*(C`L32R\*(C'\fR +instructions. The use of \f(CW\*(C`CONST16\*(C'\fR is enabled by default only if +the \f(CW\*(C`L32R\*(C'\fR instruction is not available. +.IP "\fB\-mfused\-madd\fR" 4 .IX Item "-mfused-madd" .PD 0 -.Ip "\fB\-mno-fused-madd\fR" 4 +.IP "\fB\-mno\-fused\-madd\fR" 4 .IX Item "-mno-fused-madd" .PD Enable or disable use of fused multiply/add and multiply/subtract @@ -8853,35 +10113,25 @@ precision than specified by the \s-1IEEE\s0 standard. Disabling fused multiply add/subtract instructions also ensures that the program output is not sensitive to the compiler's ability to combine multiply and add/subtract operations. -.Ip "\fB\-mserialize-volatile\fR" 4 -.IX Item "-mserialize-volatile" -.PD 0 -.Ip "\fB\-mno-serialize-volatile\fR" 4 -.IX Item "-mno-serialize-volatile" -.PD -When this option is enabled, \s-1GCC\s0 inserts \f(CW\*(C`MEMW\*(C'\fR instructions before -\&\f(CW\*(C`volatile\*(C'\fR memory references to guarantee sequential consistency. -The default is \fB\-mserialize-volatile\fR. Use -\&\fB\-mno-serialize-volatile\fR to omit the \f(CW\*(C`MEMW\*(C'\fR instructions. -.Ip "\fB\-mtext-section-literals\fR" 4 +.IP "\fB\-mtext\-section\-literals\fR" 4 .IX Item "-mtext-section-literals" .PD 0 -.Ip "\fB\-mno-text-section-literals\fR" 4 +.IP "\fB\-mno\-text\-section\-literals\fR" 4 .IX Item "-mno-text-section-literals" .PD Control the treatment of literal pools. The default is -\&\fB\-mno-text-section-literals\fR, which places literals in a separate +\&\fB\-mno\-text\-section\-literals\fR, which places literals in a separate section in the output file. This allows the literal pool to be placed in a data \s-1RAM/ROM\s0, and it also allows the linker to combine literal pools from separate object files to remove redundant literals and -improve code size. With \fB\-mtext-section-literals\fR, the literals +improve code size. With \fB\-mtext\-section\-literals\fR, the literals are interspersed in the text section in order to keep them as close as possible to their references. This may be necessary for large assembly files. -.Ip "\fB\-mtarget-align\fR" 4 +.IP "\fB\-mtarget\-align\fR" 4 .IX Item "-mtarget-align" .PD 0 -.Ip "\fB\-mno-target-align\fR" 4 +.IP "\fB\-mno\-target\-align\fR" 4 .IX Item "-mno-target-align" .PD When this option is enabled, \s-1GCC\s0 instructs the assembler to @@ -8890,14 +10140,14 @@ expense of some code density. The assembler attempts to widen density instructions to align branch targets and the instructions following call instructions. If there are not enough preceding safe density instructions to align a target, no widening will be performed. The -default is \fB\-mtarget-align\fR. These options do not affect the +default is \fB\-mtarget\-align\fR. These options do not affect the treatment of auto-aligned instructions like \f(CW\*(C`LOOP\*(C'\fR, which the assembler will always align, either by widening density instructions or by inserting no-op instructions. -.Ip "\fB\-mlongcalls\fR" 4 +.IP "\fB\-mlongcalls\fR" 4 .IX Item "-mlongcalls" .PD 0 -.Ip "\fB\-mno-longcalls\fR" 4 +.IP "\fB\-mno\-longcalls\fR" 4 .IX Item "-mno-longcalls" .PD When this option is enabled, \s-1GCC\s0 instructs the assembler to translate @@ -8906,7 +10156,7 @@ of a direct call is in the range allowed by the call instruction. This translation typically occurs for calls to functions in other source files. Specifically, the assembler translates a direct \f(CW\*(C`CALL\*(C'\fR instruction into an \f(CW\*(C`L32R\*(C'\fR followed by a \f(CW\*(C`CALLX\*(C'\fR instruction. -The default is \fB\-mno-longcalls\fR. This option should be used in +The default is \fB\-mno\-longcalls\fR. This option should be used in programs where the call target can potentially be out of range. This option is implemented in the assembler, not the compiler, so the assembly code generated by \s-1GCC\s0 will still show direct call @@ -8919,11 +10169,28 @@ These machine-independent options control the interface conventions used in code generation. .PP Most of them have both positive and negative forms; the negative form -of \fB\-ffoo\fR would be \fB\-fno-foo\fR. In the table below, only +of \fB\-ffoo\fR would be \fB\-fno\-foo\fR. In the table below, only one of the forms is listed\-\-\-the one which is not the default. You -can figure out the other form by either removing \fBno-\fR or adding +can figure out the other form by either removing \fBno\-\fR or adding it. -.Ip "\fB\-fexceptions\fR" 4 +.IP "\fB\-fbounds\-check\fR" 4 +.IX Item "-fbounds-check" +For front-ends that support it, generate additional code to check that +indices used to access arrays are within the declared range. This is +currently only supported by the Java and Fortran 77 front\-ends, where +this option defaults to true and false respectively. +.IP "\fB\-ftrapv\fR" 4 +.IX Item "-ftrapv" +This option generates traps for signed overflow on addition, subtraction, +multiplication operations. +.IP "\fB\-fwrapv\fR" 4 +.IX Item "-fwrapv" +This option instructs the compiler to assume that signed arithmetic +overflow of addition, subtraction and multiplication wraps around +using twos-complement representation. This flag enables some optimizations +and disables other. This option is enabled by default for the Java +front\-end, as required by the Java language specification. +.IP "\fB\-fexceptions\fR" 4 .IX Item "-fexceptions" Enable exception handling. Generates extra code needed to propagate exceptions. For some targets, this implies \s-1GCC\s0 will generate frame @@ -8936,7 +10203,7 @@ to enable this option when compiling C code that needs to interoperate properly with exception handlers written in \*(C+. You may also wish to disable this option if you are compiling older \*(C+ programs that don't use exception handling. -.Ip "\fB\-fnon-call-exceptions\fR" 4 +.IP "\fB\-fnon\-call\-exceptions\fR" 4 .IX Item "-fnon-call-exceptions" Generate code that allows trapping instructions to throw exceptions. Note that this requires platform-specific runtime support that does @@ -8944,18 +10211,18 @@ not exist everywhere. Moreover, it only allows \fItrapping\fR instructions to throw exceptions, i.e. memory references or floating point instructions. It does not allow exceptions to be thrown from arbitrary signal handlers such as \f(CW\*(C`SIGALRM\*(C'\fR. -.Ip "\fB\-funwind-tables\fR" 4 +.IP "\fB\-funwind\-tables\fR" 4 .IX Item "-funwind-tables" Similar to \fB\-fexceptions\fR, except that it will just generate any needed static data, but will not affect the generated code in any other way. You will normally not enable this option; instead, a language processor that needs this handling would enable it on your behalf. -.Ip "\fB\-fasynchronous-unwind-tables\fR" 4 +.IP "\fB\-fasynchronous\-unwind\-tables\fR" 4 .IX Item "-fasynchronous-unwind-tables" Generate unwind table in dwarf2 format, if supported by target machine. The table is exact at each instruction boundary, so it can be used for stack unwinding from asynchronous events (such as debugger or garbage collector). -.Ip "\fB\-fpcc-struct-return\fR" 4 +.IP "\fB\-fpcc\-struct\-return\fR" 4 .IX Item "-fpcc-struct-return" Return ``short'' \f(CW\*(C`struct\*(C'\fR and \f(CW\*(C`union\*(C'\fR values in memory like longer ones, rather than in registers. This convention is less @@ -8969,60 +10236,60 @@ on the target configuration macros. Short structures and unions are those whose size and alignment match that of some integer type. .Sp -\&\fBWarning:\fR code compiled with the \fB\-fpcc-struct-return\fR +\&\fBWarning:\fR code compiled with the \fB\-fpcc\-struct\-return\fR switch is not binary compatible with code compiled with the -\&\fB\-freg-struct-return\fR switch. +\&\fB\-freg\-struct\-return\fR switch. Use it to conform to a non-default application binary interface. -.Ip "\fB\-freg-struct-return\fR" 4 +.IP "\fB\-freg\-struct\-return\fR" 4 .IX Item "-freg-struct-return" Return \f(CW\*(C`struct\*(C'\fR and \f(CW\*(C`union\*(C'\fR values in registers when possible. This is more efficient for small structures than -\&\fB\-fpcc-struct-return\fR. +\&\fB\-fpcc\-struct\-return\fR. .Sp -If you specify neither \fB\-fpcc-struct-return\fR nor -\&\fB\-freg-struct-return\fR, \s-1GCC\s0 defaults to whichever convention is +If you specify neither \fB\-fpcc\-struct\-return\fR nor +\&\fB\-freg\-struct\-return\fR, \s-1GCC\s0 defaults to whichever convention is standard for the target. If there is no standard convention, \s-1GCC\s0 -defaults to \fB\-fpcc-struct-return\fR, except on targets where \s-1GCC\s0 is +defaults to \fB\-fpcc\-struct\-return\fR, except on targets where \s-1GCC\s0 is the principal compiler. In those cases, we can choose the standard, and we chose the more efficient register return alternative. .Sp -\&\fBWarning:\fR code compiled with the \fB\-freg-struct-return\fR +\&\fBWarning:\fR code compiled with the \fB\-freg\-struct\-return\fR switch is not binary compatible with code compiled with the -\&\fB\-fpcc-struct-return\fR switch. +\&\fB\-fpcc\-struct\-return\fR switch. Use it to conform to a non-default application binary interface. -.Ip "\fB\-fshort-enums\fR" 4 +.IP "\fB\-fshort\-enums\fR" 4 .IX Item "-fshort-enums" Allocate to an \f(CW\*(C`enum\*(C'\fR type only as many bytes as it needs for the declared range of possible values. Specifically, the \f(CW\*(C`enum\*(C'\fR type will be equivalent to the smallest integer type which has enough room. .Sp -\&\fBWarning:\fR the \fB\-fshort-enums\fR switch causes \s-1GCC\s0 to generate +\&\fBWarning:\fR the \fB\-fshort\-enums\fR switch causes \s-1GCC\s0 to generate code that is not binary compatible with code generated without that switch. Use it to conform to a non-default application binary interface. -.Ip "\fB\-fshort-double\fR" 4 +.IP "\fB\-fshort\-double\fR" 4 .IX Item "-fshort-double" Use the same size for \f(CW\*(C`double\*(C'\fR as for \f(CW\*(C`float\*(C'\fR. .Sp -\&\fBWarning:\fR the \fB\-fshort-double\fR switch causes \s-1GCC\s0 to generate +\&\fBWarning:\fR the \fB\-fshort\-double\fR switch causes \s-1GCC\s0 to generate code that is not binary compatible with code generated without that switch. Use it to conform to a non-default application binary interface. -.Ip "\fB\-fshort-wchar\fR" 4 +.IP "\fB\-fshort\-wchar\fR" 4 .IX Item "-fshort-wchar" Override the underlying type for \fBwchar_t\fR to be \fBshort unsigned int\fR instead of the default for the target. This option is useful for building programs to run under \s-1WINE\s0. .Sp -\&\fBWarning:\fR the \fB\-fshort-wchar\fR switch causes \s-1GCC\s0 to generate +\&\fBWarning:\fR the \fB\-fshort\-wchar\fR switch causes \s-1GCC\s0 to generate code that is not binary compatible with code generated without that switch. Use it to conform to a non-default application binary interface. -.Ip "\fB\-fshared-data\fR" 4 +.IP "\fB\-fshared\-data\fR" 4 .IX Item "-fshared-data" -Requests that the data and non-\f(CW\*(C`const\*(C'\fR variables of this +Requests that the data and non\-\f(CW\*(C`const\*(C'\fR variables of this compilation be shared data rather than private data. The distinction makes sense only on certain operating systems, where shared data is shared between processes running the same program, while private data exists in one copy per process. -.Ip "\fB\-fno-common\fR" 4 +.IP "\fB\-fno\-common\fR" 4 .IX Item "-fno-common" In C, allocate even uninitialized global variables in the data section of the object file, rather than generating them as common blocks. This has the @@ -9030,48 +10297,27 @@ effect that if the same variable is declared (without \f(CW\*(C`extern\*(C'\fR) two different compilations, you will get an error when you link them. The only reason this might be useful is if you wish to verify that the program will work on other systems which always work this way. -.Ip "\fB\-fno-ident\fR" 4 +.IP "\fB\-fno\-ident\fR" 4 .IX Item "-fno-ident" Ignore the \fB#ident\fR directive. -.Ip "\fB\-fno-gnu-linker\fR" 4 -.IX Item "-fno-gnu-linker" -Do not output global initializations (such as \*(C+ constructors and -destructors) in the form used by the \s-1GNU\s0 linker (on systems where the \s-1GNU\s0 -linker is the standard method of handling them). Use this option when -you want to use a non-GNU linker, which also requires using the -\&\fBcollect2\fR program to make sure the system linker includes -constructors and destructors. (\fBcollect2\fR is included in the \s-1GCC\s0 -distribution.) For systems which \fImust\fR use \fBcollect2\fR, the -compiler driver \fBgcc\fR is configured to do this automatically. -.Ip "\fB\-finhibit-size-directive\fR" 4 +.IP "\fB\-finhibit\-size\-directive\fR" 4 .IX Item "-finhibit-size-directive" Don't output a \f(CW\*(C`.size\*(C'\fR assembler directive, or anything else that would cause trouble if the function is split in the middle, and the two halves are placed at locations far apart in memory. This option is used when compiling \fIcrtstuff.c\fR; you should not need to use it for anything else. -.Ip "\fB\-fverbose-asm\fR" 4 +.IP "\fB\-fverbose\-asm\fR" 4 .IX Item "-fverbose-asm" Put extra commentary information in the generated assembly code to make it more readable. This option is generally only of use to those who actually need to read the generated assembly code (perhaps while debugging the compiler itself). .Sp -\&\fB\-fno-verbose-asm\fR, the default, causes the +\&\fB\-fno\-verbose\-asm\fR, the default, causes the extra information to be omitted and is useful when comparing two assembler files. -.Ip "\fB\-fvolatile\fR" 4 -.IX Item "-fvolatile" -Consider all memory references through pointers to be volatile. -.Ip "\fB\-fvolatile-global\fR" 4 -.IX Item "-fvolatile-global" -Consider all memory references to extern and global data items to -be volatile. \s-1GCC\s0 does not consider static data items to be volatile -because of this switch. -.Ip "\fB\-fvolatile-static\fR" 4 -.IX Item "-fvolatile-static" -Consider all memory references to static data to be volatile. -.Ip "\fB\-fpic\fR" 4 +.IP "\fB\-fpic\fR" 4 .IX Item "-fpic" Generate position-independent code (\s-1PIC\s0) suitable for use in a shared library, if supported for the target machine. Such code accesses all @@ -9081,23 +10327,33 @@ loader is not part of \s-1GCC\s0; it is part of the operating system). If the \s-1GOT\s0 size for the linked executable exceeds a machine-specific maximum size, you get an error message from the linker indicating that \&\fB\-fpic\fR does not work; in that case, recompile with \fB\-fPIC\fR -instead. (These maximums are 16k on the m88k, 8k on the Sparc, and 32k +instead. (These maximums are 8k on the \s-1SPARC\s0 and 32k on the m68k and \s-1RS/6000\s0. The 386 has no such limit.) .Sp Position-independent code requires special support, and therefore works only on certain machines. For the 386, \s-1GCC\s0 supports \s-1PIC\s0 for System V but not for the Sun 386i. Code generated for the \s-1IBM\s0 \s-1RS/6000\s0 is always -position-independent. -.Ip "\fB\-fPIC\fR" 4 +position\-independent. +.IP "\fB\-fPIC\fR" 4 .IX Item "-fPIC" If supported for the target machine, emit position-independent code, suitable for dynamic linking and avoiding any limit on the size of the -global offset table. This option makes a difference on the m68k, m88k, -and the Sparc. +global offset table. This option makes a difference on the m68k +and the \s-1SPARC\s0. .Sp Position-independent code requires special support, and therefore works only on certain machines. -.Ip "\fB\-ffixed-\fR\fIreg\fR" 4 +.IP "\fB\-fpie\fR" 4 +.IX Item "-fpie" +.PD 0 +.IP "\fB\-fPIE\fR" 4 +.IX Item "-fPIE" +.PD +These options are similar to \fB\-fpic\fR and \fB\-fPIC\fR, but +generated position independent code can be only linked into executables. +Usually these options are used when \fB\-pie\fR \s-1GCC\s0 option will be +used during linking. +.IP "\fB\-ffixed\-\fR\fIreg\fR" 4 .IX Item "-ffixed-reg" Treat the register named \fIreg\fR as a fixed register; generated code should never refer to it (except perhaps as a stack pointer, frame @@ -9109,7 +10365,7 @@ macro in the machine description macro file. .Sp This flag does not have a negative form, because it specifies a three-way choice. -.Ip "\fB\-fcall-used-\fR\fIreg\fR" 4 +.IP "\fB\-fcall\-used\-\fR\fIreg\fR" 4 .IX Item "-fcall-used-reg" Treat the register named \fIreg\fR as an allocable register that is clobbered by function calls. It may be allocated for temporaries or @@ -9122,7 +10378,7 @@ the machine's execution model will produce disastrous results. .Sp This flag does not have a negative form, because it specifies a three-way choice. -.Ip "\fB\-fcall-saved-\fR\fIreg\fR" 4 +.IP "\fB\-fcall\-saved\-\fR\fIreg\fR" 4 .IX Item "-fcall-saved-reg" Treat the register named \fIreg\fR as an allocable register saved by functions. It may be allocated even for temporaries or variables that @@ -9138,15 +10394,15 @@ a register in which function values may be returned. .Sp This flag does not have a negative form, because it specifies a three-way choice. -.Ip "\fB\-fpack-struct\fR" 4 +.IP "\fB\-fpack\-struct\fR" 4 .IX Item "-fpack-struct" Pack all structure members together without holes. .Sp -\&\fBWarning:\fR the \fB\-fpack-struct\fR switch causes \s-1GCC\s0 to generate +\&\fBWarning:\fR the \fB\-fpack\-struct\fR switch causes \s-1GCC\s0 to generate code that is not binary compatible with code generated without that switch. -Additionally, it makes the code suboptimial. +Additionally, it makes the code suboptimal. Use it to conform to a non-default application binary interface. -.Ip "\fB\-finstrument-functions\fR" 4 +.IP "\fB\-finstrument\-functions\fR" 4 .IX Item "-finstrument-functions" Generate instrumentation calls for entry and exit to functions. Just after function entry and just before function exit, the following @@ -9162,19 +10418,12 @@ profiling functions otherwise.) \& void __cyg_profile_func_exit (void *this_fn, \& void *call_site); .Ve +.Sp The first argument is the address of the start of the current function, which may be looked up exactly in the symbol table. .Sp -This instrumentation is also done for functions expanded inline in other -functions. The profiling calls will indicate where, conceptually, the -inline function is entered and exited. This means that addressable -versions of such functions must be available. If all your uses of a -function are expanded inline, this may mean an additional expansion of -code size. If you use \fBextern inline\fR in your C code, an -addressable version of such functions must be provided. (This is -normally the case anyways, but if you get lucky and the optimizer always -expands the functions inline, you might have gotten away without -providing static copies.) +This currently disables function inlining. This restriction is +expected to be removed in future releases. .Sp A function may be given the attribute \f(CW\*(C`no_instrument_function\*(C'\fR, in which case this instrumentation will not be done. This can be used, for @@ -9182,7 +10431,7 @@ example, for the profiling functions listed above, high-priority interrupt routines, and any functions from which the profiling functions cannot safely be called (perhaps signal handlers, if the profiling routines generate output or allocate memory). -.Ip "\fB\-fstack-check\fR" 4 +.IP "\fB\-fstack\-check\fR" 4 .IX Item "-fstack-check" Generate code to verify that you do not go beyond the boundary of the stack. You should specify this flag if you are running in an @@ -9193,12 +10442,12 @@ detected on nearly all systems if there is only one stack. Note that this switch does not actually cause checking to be done; the operating system must do that. The switch causes generation of code to ensure that the operating system sees the stack being extended. -.Ip "\fB\-fstack-limit-register=\fR\fIreg\fR" 4 +.IP "\fB\-fstack\-limit\-register=\fR\fIreg\fR" 4 .IX Item "-fstack-limit-register=reg" .PD 0 -.Ip "\fB\-fstack-limit-symbol=\fR\fIsym\fR" 4 +.IP "\fB\-fstack\-limit\-symbol=\fR\fIsym\fR" 4 .IX Item "-fstack-limit-symbol=sym" -.Ip "\fB\-fno-stack-limit\fR" 4 +.IP "\fB\-fno\-stack\-limit\fR" 4 .IX Item "-fno-stack-limit" .PD Generate code to ensure that the stack does not grow beyond a certain value, @@ -9209,37 +10458,45 @@ it is possible to catch the signal without taking special precautions. .Sp For instance, if the stack starts at absolute address \fB0x80000000\fR and grows downwards, you can use the flags -\&\fB\-fstack-limit-symbol=_\|_stack_limit\fR and +\&\fB\-fstack\-limit\-symbol=_\|_stack_limit\fR and \&\fB\-Wl,\-\-defsym,_\|_stack_limit=0x7ffe0000\fR to enforce a stack limit of 128KB. Note that this may only work with the \s-1GNU\s0 linker. -.Ip "\fB\-fargument-alias\fR" 4 +.IP "\fB\-fargument\-alias\fR" 4 .IX Item "-fargument-alias" .PD 0 -.Ip "\fB\-fargument-noalias\fR" 4 +.IP "\fB\-fargument\-noalias\fR" 4 .IX Item "-fargument-noalias" -.Ip "\fB\-fargument-noalias-global\fR" 4 +.IP "\fB\-fargument\-noalias\-global\fR" 4 .IX Item "-fargument-noalias-global" .PD Specify the possible relationships among parameters and between parameters and global data. .Sp -\&\fB\-fargument-alias\fR specifies that arguments (parameters) may -alias each other and may alias global storage.\fB\-fargument-noalias\fR specifies that arguments do not alias -each other, but may alias global storage.\fB\-fargument-noalias-global\fR specifies that arguments do not +\&\fB\-fargument\-alias\fR specifies that arguments (parameters) may +alias each other and may alias global storage.\fB\-fargument\-noalias\fR specifies that arguments do not alias +each other, but may alias global storage.\fB\-fargument\-noalias\-global\fR specifies that arguments do not alias each other and do not alias global storage. .Sp Each language will automatically use whatever option is required by the language standard. You should not need to use these options yourself. -.Ip "\fB\-fleading-underscore\fR" 4 +.IP "\fB\-fleading\-underscore\fR" 4 .IX Item "-fleading-underscore" -This option and its counterpart, \fB\-fno-leading-underscore\fR, forcibly +This option and its counterpart, \fB\-fno\-leading\-underscore\fR, forcibly change the way C symbols are represented in the object file. One use is to help link with legacy assembly code. .Sp -\&\fBWarning:\fR the \fB\-fleading-underscore\fR switch causes \s-1GCC\s0 to +\&\fBWarning:\fR the \fB\-fleading\-underscore\fR switch causes \s-1GCC\s0 to generate code that is not binary compatible with code generated without that switch. Use it to conform to a non-default application binary interface. Not all targets provide complete support for this switch. +.IP "\fB\-ftls\-model=\fR\fImodel\fR" 4 +.IX Item "-ftls-model=model" +Alter the thread-local storage model to be used. +The \fImodel\fR argument should be one of \f(CW\*(C`global\-dynamic\*(C'\fR, +\&\f(CW\*(C`local\-dynamic\*(C'\fR, \f(CW\*(C`initial\-exec\*(C'\fR or \f(CW\*(C`local\-exec\*(C'\fR. +.Sp +The default without \fB\-fpic\fR is \f(CW\*(C`initial\-exec\*(C'\fR; with +\&\fB\-fpic\fR the default is \f(CW\*(C`global\-dynamic\*(C'\fR. .SH "ENVIRONMENT" .IX Header "ENVIRONMENT" This section describes several environment variables that affect how \s-1GCC\s0 @@ -9251,14 +10508,14 @@ Note that you can also specify places to search using options such as \&\fB\-B\fR, \fB\-I\fR and \fB\-L\fR. These take precedence over places specified using environment variables, which in turn take precedence over those specified by the configuration of \s-1GCC\s0. -.Ip "\fB\s-1LANG\s0\fR" 4 +.IP "\fB\s-1LANG\s0\fR" 4 .IX Item "LANG" .PD 0 -.Ip "\fB\s-1LC_CTYPE\s0\fR" 4 +.IP "\fB\s-1LC_CTYPE\s0\fR" 4 .IX Item "LC_CTYPE" -.Ip "\fB\s-1LC_MESSAGES\s0\fR" 4 +.IP "\fB\s-1LC_MESSAGES\s0\fR" 4 .IX Item "LC_MESSAGES" -.Ip "\fB\s-1LC_ALL\s0\fR" 4 +.IP "\fB\s-1LC_ALL\s0\fR" 4 .IX Item "LC_ALL" .PD These environment variables control the way that \s-1GCC\s0 uses @@ -9266,8 +10523,8 @@ localization information that allow \s-1GCC\s0 to work with different national conventions. \s-1GCC\s0 inspects the locale categories \&\fB\s-1LC_CTYPE\s0\fR and \fB\s-1LC_MESSAGES\s0\fR if it has been configured to do so. These locale categories can be set to any value supported by your -installation. A typical value is \fBen_UK\fR for English in the United -Kingdom. +installation. A typical value is \fBen_GB.UTF\-8\fR for English in the United +Kingdom encoded in \s-1UTF\-8\s0. .Sp The \fB\s-1LC_CTYPE\s0\fR environment variable specifies character classification. \s-1GCC\s0 uses it to determine the character boundaries in @@ -9283,14 +10540,14 @@ of \fB\s-1LC_CTYPE\s0\fR and \fB\s-1LC_MESSAGES\s0\fR; otherwise, \fB\s-1LC_CTYP and \fB\s-1LC_MESSAGES\s0\fR default to the value of the \fB\s-1LANG\s0\fR environment variable. If none of these variables are set, \s-1GCC\s0 defaults to traditional C English behavior. -.Ip "\fB\s-1TMPDIR\s0\fR" 4 +.IP "\fB\s-1TMPDIR\s0\fR" 4 .IX Item "TMPDIR" If \fB\s-1TMPDIR\s0\fR is set, it specifies the directory to use for temporary files. \s-1GCC\s0 uses temporary files to hold the output of one stage of compilation which is to be used as input to the next stage: for example, the output of the preprocessor, which is the input to the compiler proper. -.Ip "\fB\s-1GCC_EXEC_PREFIX\s0\fR" 4 +.IP "\fB\s-1GCC_EXEC_PREFIX\s0\fR" 4 .IX Item "GCC_EXEC_PREFIX" If \fB\s-1GCC_EXEC_PREFIX\s0\fR is set, it specifies a prefix to use in the names of the subprograms executed by the compiler. No slash is added @@ -9304,7 +10561,7 @@ If \s-1GCC\s0 cannot find the subprogram using the specified prefix, it tries looking in the usual places for the subprogram. .Sp The default value of \fB\s-1GCC_EXEC_PREFIX\s0\fR is -\&\fI\fIprefix\fI/lib/gcc-lib/\fR where \fIprefix\fR is the value +\&\fI\fIprefix\fI/lib/gcc/\fR where \fIprefix\fR is the value of \f(CW\*(C`prefix\*(C'\fR when you ran the \fIconfigure\fR script. .Sp Other prefixes specified with \fB\-B\fR take precedence over this prefix. @@ -9314,20 +10571,20 @@ used for linking. .Sp In addition, the prefix is used in an unusual way in finding the directories to search for header files. For each of the standard -directories whose name normally begins with \fB/usr/local/lib/gcc-lib\fR +directories whose name normally begins with \fB/usr/local/lib/gcc\fR (more precisely, with the value of \fB\s-1GCC_INCLUDE_DIR\s0\fR), \s-1GCC\s0 tries replacing that beginning with the specified prefix to produce an alternate directory name. Thus, with \fB\-Bfoo/\fR, \s-1GCC\s0 will search \&\fIfoo/bar\fR where it would normally search \fI/usr/local/lib/bar\fR. These alternate directories are searched first; the standard directories come next. -.Ip "\fB\s-1COMPILER_PATH\s0\fR" 4 +.IP "\fB\s-1COMPILER_PATH\s0\fR" 4 .IX Item "COMPILER_PATH" The value of \fB\s-1COMPILER_PATH\s0\fR is a colon-separated list of directories, much like \fB\s-1PATH\s0\fR. \s-1GCC\s0 tries the directories thus specified when searching for subprograms, if it can't find the subprograms using \fB\s-1GCC_EXEC_PREFIX\s0\fR. -.Ip "\fB\s-1LIBRARY_PATH\s0\fR" 4 +.IP "\fB\s-1LIBRARY_PATH\s0\fR" 4 .IX Item "LIBRARY_PATH" The value of \fB\s-1LIBRARY_PATH\s0\fR is a colon-separated list of directories, much like \fB\s-1PATH\s0\fR. When configured as a native compiler, @@ -9336,7 +10593,7 @@ linker files, if it can't find them using \fB\s-1GCC_EXEC_PREFIX\s0\fR. Linking using \s-1GCC\s0 also uses these directories when searching for ordinary libraries for the \fB\-l\fR option (but directories specified with \&\fB\-L\fR come first). -.Ip "\fB\s-1LANG\s0\fR" 4 +.IP "\fB\s-1LANG\s0\fR" 4 .IX Item "LANG" This variable is used to pass locale information to the compiler. One way in which this information is used is to determine the character set to be used @@ -9344,13 +10601,13 @@ when character literals, string literals and comments are parsed in C and \*(C+. When the compiler is configured to allow multibyte characters, the following values for \fB\s-1LANG\s0\fR are recognized: .RS 4 -.Ip "\fBC-JIS\fR" 4 +.IP "\fBC\-JIS\fR" 4 .IX Item "C-JIS" Recognize \s-1JIS\s0 characters. -.Ip "\fBC-SJIS\fR" 4 +.IP "\fBC\-SJIS\fR" 4 .IX Item "C-SJIS" Recognize \s-1SJIS\s0 characters. -.Ip "\fBC-EUCJP\fR" 4 +.IP "\fBC\-EUCJP\fR" 4 .IX Item "C-EUCJP" Recognize \s-1EUCJP\s0 characters. .RE @@ -9363,34 +10620,39 @@ recognize and translate multibyte characters. .PP Some additional environments variables affect the behavior of the preprocessor. -.Ip "\fB\s-1CPATH\s0\fR" 4 +.IP "\fB\s-1CPATH\s0\fR" 4 .IX Item "CPATH" .PD 0 -.Ip "\fBC_INCLUDE_PATH\fR" 4 +.IP "\fBC_INCLUDE_PATH\fR" 4 .IX Item "C_INCLUDE_PATH" -.Ip "\fB\s-1CPLUS_INCLUDE_PATH\s0\fR" 4 +.IP "\fB\s-1CPLUS_INCLUDE_PATH\s0\fR" 4 .IX Item "CPLUS_INCLUDE_PATH" -.Ip "\fB\s-1OBJC_INCLUDE_PATH\s0\fR" 4 +.IP "\fB\s-1OBJC_INCLUDE_PATH\s0\fR" 4 .IX Item "OBJC_INCLUDE_PATH" .PD Each variable's value is a list of directories separated by a special character, much like \fB\s-1PATH\s0\fR, in which to look for header files. The special character, \f(CW\*(C`PATH_SEPARATOR\*(C'\fR, is target-dependent and -determined at \s-1GCC\s0 build time. For Windows-based targets it is a +determined at \s-1GCC\s0 build time. For Microsoft Windows-based targets it is a semicolon, and for almost all other targets it is a colon. .Sp \&\fB\s-1CPATH\s0\fR specifies a list of directories to be searched as if specified with \fB\-I\fR, but after any paths given with \fB\-I\fR -options on the command line. The environment variable is used +options on the command line. This environment variable is used regardless of which language is being preprocessed. .Sp The remaining environment variables apply only when preprocessing the particular language indicated. Each specifies a list of directories to be searched as if specified with \fB\-isystem\fR, but after any paths given with \fB\-isystem\fR options on the command line. -.Ip "\fB\s-1DEPENDENCIES_OUTPUT\s0\fR" 4 +.Sp +In all these variables, an empty element instructs the compiler to +search its current working directory. Empty elements can appear at the +beginning or end of a path. For instance, if the value of +\&\fB\s-1CPATH\s0\fR is \f(CW\*(C`:/special/include\*(C'\fR, that has the same +effect as \fB\-I.\ \-I/special/include\fR. +.IP "\fB\s-1DEPENDENCIES_OUTPUT\s0\fR" 4 .IX Item "DEPENDENCIES_OUTPUT" -@anchor{\s-1DEPENDENCIES_OUTPUT\s0} If this variable is set, its value specifies how to output dependencies for Make based on the non-system header files processed by the compiler. System header files are ignored in the dependency @@ -9405,13 +10667,12 @@ file \fIfile\fR using \fItarget\fR as the target name. In other words, this environment variable is equivalent to combining the options \fB\-MM\fR and \fB\-MF\fR, with an optional \fB\-MT\fR switch too. -.Ip "\fB\s-1SUNPRO_DEPENDENCIES\s0\fR" 4 +.IP "\fB\s-1SUNPRO_DEPENDENCIES\s0\fR" 4 .IX Item "SUNPRO_DEPENDENCIES" -This variable is the same as the environment variable -\&\fB\s-1DEPENDENCIES_OUTPUT\s0\fR, except that -system header files are not ignored, so it implies \fB\-M\fR rather -than \fB\-MM\fR. However, the dependence on the main input file is -omitted. +This variable is the same as \fB\s-1DEPENDENCIES_OUTPUT\s0\fR (see above), +except that system header files are not ignored, so it implies +\&\fB\-M\fR rather than \fB\-MM\fR. However, the dependence on the +main input file is omitted. .SH "BUGS" .IX Header "BUGS" For instructions on reporting bugs, see @@ -9419,7 +10680,7 @@ For instructions on reporting bugs, see script to report bugs is recommended. .SH "FOOTNOTES" .IX Header "FOOTNOTES" -.Ip "1." 4 +.IP "1." 4 On some systems, \fBgcc \-shared\fR needs to build supplementary stub code for constructors to work. On multi-libbed systems, \fBgcc \-shared\fR must select the correct support @@ -9428,7 +10689,7 @@ to subtle defects. Supplying them in cases where they are not necessary is innocuous. .SH "SEE ALSO" .IX Header "SEE ALSO" -\&\fIgpl\fR\|(7), \fIgfdl\fR\|(7), \fIfsf-funding\fR\|(7), +\&\fIgpl\fR\|(7), \fIgfdl\fR\|(7), \fIfsf\-funding\fR\|(7), \&\fIcpp\fR\|(1), \fIgcov\fR\|(1), \fIg77\fR\|(1), \fIas\fR\|(1), \fIld\fR\|(1), \fIgdb\fR\|(1), \fIadb\fR\|(1), \fIdbx\fR\|(1), \fIsdb\fR\|(1) and the Info entries for \fIgcc\fR, \fIcpp\fR, \fIg77\fR, \fIas\fR, \&\fIld\fR, \fIbinutils\fR and \fIgdb\fR. @@ -9440,10 +10701,10 @@ for contributors to \s-1GCC\s0. .SH "COPYRIGHT" .IX Header "COPYRIGHT" Copyright (c) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, -1998, 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc. +1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc. .PP Permission is granted to copy, distribute and/or modify this document -under the terms of the \s-1GNU\s0 Free Documentation License, Version 1.1 or +under the terms of the \s-1GNU\s0 Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with the Invariant Sections being ``\s-1GNU\s0 General Public License'' and ``Funding Free Software'', the Front-Cover texts being (a) (see below), and with @@ -9455,6 +10716,7 @@ included in the \fIgfdl\fR\|(7) man page. .Vb 1 \& A GNU Manual .Ve +.PP (b) The \s-1FSF\s0's Back-Cover Text is: .PP .Vb 3 diff --git a/contrib/gcc/doc/gcov.1 b/contrib/gcc/doc/gcov.1 index 44d1e33..d0abb46 100644 --- a/contrib/gcc/doc/gcov.1 +++ b/contrib/gcc/doc/gcov.1 @@ -1,8 +1,7 @@ -.\" Automatically generated by Pod::Man version 1.15 -.\" Wed Feb 5 03:13:55 2003 +.\" Automatically generated by Pod::Man v1.37, Pod::Parser v1.14 .\" .\" Standard preamble: -.\" ====================================================================== +.\" ======================================================================== .de Sh \" Subsection heading .br .if t .Sp @@ -15,12 +14,6 @@ .if t .sp .5v .if n .sp .. -.de Ip \" List item -.br -.ie \\n(.$>=3 .ne \\$3 -.el .ne 3 -.IP "\\$1" \\$2 -.. .de Vb \" Begin verbatim text .ft CW .nf @@ -28,15 +21,14 @@ .. .de Ve \" End verbatim text .ft R - .fi .. .\" Set up some character translations and predefined strings. \*(-- will .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left .\" double quote, and \*(R" will give a right double quote. | will give a -.\" real vertical bar. \*(C+ will give a nicer C++. Capital omega is used -.\" to do unbreakable dashes and therefore won't be available. \*(C` and -.\" \*(C' expand to `' in nroff, nothing in troff, for use with C<> +.\" real vertical bar. \*(C+ will give a nicer C++. Capital omega is used to +.\" do unbreakable dashes and therefore won't be available. \*(C` and \*(C' +.\" expand to `' in nroff, nothing in troff, for use with C<>. .tr \(*W-|\(bv\*(Tr .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' .ie n \{\ @@ -56,10 +48,10 @@ . ds R" '' 'br\} .\" -.\" If the F register is turned on, we'll generate index entries on stderr -.\" for titles (.TH), headers (.SH), subsections (.Sh), items (.Ip), and -.\" index entries marked with X<> in POD. Of course, you'll have to process -.\" the output yourself in some meaningful fashion. +.\" If the F register is turned on, we'll generate index entries on stderr for +.\" titles (.TH), headers (.SH), subsections (.Sh), items (.Ip), and index +.\" entries marked with X<> in POD. Of course, you'll have to process the +.\" output yourself in some meaningful fashion. .if \nF \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" @@ -68,14 +60,13 @@ . rr F .\} .\" -.\" For nroff, turn off justification. Always turn off hyphenation; it -.\" makes way too many mistakes in technical documents. +.\" For nroff, turn off justification. Always turn off hyphenation; it makes +.\" way too many mistakes in technical documents. .hy 0 .if n .na .\" .\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2). .\" Fear. Run. Save yourself. No user-serviceable parts. -.bd B 3 . \" fudge factors for nroff and troff .if n \{\ . ds #H 0 @@ -135,38 +126,43 @@ . ds Ae AE .\} .rm #[ #] #H #V #F C -.\" ====================================================================== +.\" ======================================================================== .\" .IX Title "GCOV 1" -.TH GCOV 1 "gcc-3.2.2" "2003-02-05" "GNU" -.UC +.TH GCOV 1 "2006-03-06" "gcc-3.4.6" "GNU" .SH "NAME" gcov \- coverage testing tool .SH "SYNOPSIS" .IX Header "SYNOPSIS" -gcov [\fB\-v\fR|\fB\*(--version\fR] [\fB\-h\fR|\fB\*(--help\fR] - [\fB\-b\fR|\fB\*(--branch-probabilities\fR] [\fB\-c\fR|\fB\*(--branch-counts\fR] - [\fB\-n\fR|\fB\*(--no-output\fR] [\fB\-l\fR|\fB\*(--long-file-names\fR] - [\fB\-f\fR|\fB\*(--function-summaries\fR] - [\fB\-o\fR|\fB\*(--object-directory\fR \fIdirectory\fR] \fIsourcefile\fR +gcov [\fB\-v\fR|\fB\-\-version\fR] [\fB\-h\fR|\fB\-\-help\fR] + [\fB\-a\fR|\fB\-\-all\-blocks\fR] + [\fB\-b\fR|\fB\-\-branch\-probabilities\fR] + [\fB\-c\fR|\fB\-\-branch\-counts\fR] + [\fB\-n\fR|\fB\-\-no\-output\fR] + [\fB\-l\fR|\fB\-\-long\-file\-names\fR] + [\fB\-p\fR|\fB\-\-preserve\-paths\fR] + [\fB\-f\fR|\fB\-\-function\-summaries\fR] + [\fB\-o\fR|\fB\-\-object\-directory\fR \fIdirectory|file\fR] \fIsourcefile\fR + [\fB\-u\fR|\fB\-\-unconditional\-branches\fR] .SH "DESCRIPTION" .IX Header "DESCRIPTION" \&\fBgcov\fR is a test coverage program. Use it in concert with \s-1GCC\s0 -to analyze your programs to help create more efficient, faster -running code. You can use \fBgcov\fR as a profiling tool to help -discover where your optimization efforts will best affect your code. You -can also use \fBgcov\fR along with the other profiling tool, -\&\fBgprof\fR, to assess which parts of your code use the greatest amount -of computing time. +to analyze your programs to help create more efficient, faster running +code and to discover untested parts of your program. You can use +\&\fBgcov\fR as a profiling tool to help discover where your +optimization efforts will best affect your code. You can also use +\&\fBgcov\fR along with the other profiling tool, \fBgprof\fR, to +assess which parts of your code use the greatest amount of computing +time. .PP Profiling tools help you analyze your code's performance. Using a profiler such as \fBgcov\fR or \fBgprof\fR, you can find out some basic performance statistics, such as: -.Ip "\(bu" 4 +.IP "\(bu" 4 how often each line of code executes -.Ip "\(bu" 4 +.IP "\(bu" 4 what lines of code are actually executed -.Ip "\(bu" 4 +.IP "\(bu" 4 how much computing time each section of code uses .PP Once you know these things about how your code works when compiled, you @@ -204,84 +200,153 @@ timing information you can use along with the information you get from compatible with any other profiling or test coverage mechanism. .SH "OPTIONS" .IX Header "OPTIONS" -.Ip "\fB\-h\fR" 4 +.IP "\fB\-h\fR" 4 .IX Item "-h" .PD 0 -.Ip "\fB\*(--help\fR" 4 -.IX Item "help" +.IP "\fB\-\-help\fR" 4 +.IX Item "--help" .PD Display help about using \fBgcov\fR (on the standard output), and exit without doing any further processing. -.Ip "\fB\-v\fR" 4 +.IP "\fB\-v\fR" 4 .IX Item "-v" .PD 0 -.Ip "\fB\*(--version\fR" 4 -.IX Item "version" +.IP "\fB\-\-version\fR" 4 +.IX Item "--version" .PD Display the \fBgcov\fR version number (on the standard output), and exit without doing any further processing. -.Ip "\fB\-b\fR" 4 +.IP "\fB\-a\fR" 4 +.IX Item "-a" +.PD 0 +.IP "\fB\-\-all\-blocks\fR" 4 +.IX Item "--all-blocks" +.PD +Write individual execution counts for every basic block. Normally gcov +outputs execution counts only for the main blocks of a line. With this +option you can determine if blocks within a single line are not being +executed. +.IP "\fB\-b\fR" 4 .IX Item "-b" .PD 0 -.Ip "\fB\*(--branch-probabilities\fR" 4 -.IX Item "branch-probabilities" +.IP "\fB\-\-branch\-probabilities\fR" 4 +.IX Item "--branch-probabilities" .PD Write branch frequencies to the output file, and write branch summary info to the standard output. This option allows you to see how often -each branch in your program was taken. -.Ip "\fB\-c\fR" 4 +each branch in your program was taken. Unconditional branches will not +be shown, unless the \fB\-u\fR option is given. +.IP "\fB\-c\fR" 4 .IX Item "-c" .PD 0 -.Ip "\fB\*(--branch-counts\fR" 4 -.IX Item "branch-counts" +.IP "\fB\-\-branch\-counts\fR" 4 +.IX Item "--branch-counts" .PD Write branch frequencies as the number of branches taken, rather than the percentage of branches taken. -.Ip "\fB\-n\fR" 4 +.IP "\fB\-n\fR" 4 .IX Item "-n" .PD 0 -.Ip "\fB\*(--no-output\fR" 4 -.IX Item "no-output" +.IP "\fB\-\-no\-output\fR" 4 +.IX Item "--no-output" .PD Do not create the \fBgcov\fR output file. -.Ip "\fB\-l\fR" 4 +.IP "\fB\-l\fR" 4 .IX Item "-l" .PD 0 -.Ip "\fB\*(--long-file-names\fR" 4 -.IX Item "long-file-names" +.IP "\fB\-\-long\-file\-names\fR" 4 +.IX Item "--long-file-names" .PD Create long file names for included source files. For example, if the header file \fIx.h\fR contains code, and was included in the file \&\fIa.c\fR, then running \fBgcov\fR on the file \fIa.c\fR will produce -an output file called \fIa.c.x.h.gcov\fR instead of \fIx.h.gcov\fR. -This can be useful if \fIx.h\fR is included in multiple source files. -.Ip "\fB\-f\fR" 4 +an output file called \fIa.c##x.h.gcov\fR instead of \fIx.h.gcov\fR. +This can be useful if \fIx.h\fR is included in multiple source +files. If you uses the \fB\-p\fR option, both the including and +included file names will be complete path names. +.IP "\fB\-p\fR" 4 +.IX Item "-p" +.PD 0 +.IP "\fB\-\-preserve\-paths\fR" 4 +.IX Item "--preserve-paths" +.PD +Preserve complete path information in the names of generated +\&\fI.gcov\fR files. Without this option, just the filename component is +used. With this option, all directories are used, with '/' characters +translated to '#' characters, '.' directory components removed and '..' +components renamed to '^'. This is useful if sourcefiles are in several +different directories. It also affects the \fB\-l\fR option. +.IP "\fB\-f\fR" 4 .IX Item "-f" .PD 0 -.Ip "\fB\*(--function-summaries\fR" 4 -.IX Item "function-summaries" +.IP "\fB\-\-function\-summaries\fR" 4 +.IX Item "--function-summaries" .PD Output summaries for each function in addition to the file level summary. -.Ip "\fB\-o\fR \fIdirectory\fR" 4 -.IX Item "-o directory" +.IP "\fB\-o\fR \fIdirectory|file\fR" 4 +.IX Item "-o directory|file" +.PD 0 +.IP "\fB\-\-object\-directory\fR \fIdirectory\fR" 4 +.IX Item "--object-directory directory" +.IP "\fB\-\-object\-file\fR \fIfile\fR" 4 +.IX Item "--object-file file" +.PD +Specify either the directory containing the gcov data files, or the +object path name. The \fI.gcno\fR, and +\&\fI.gcda\fR data files are searched for using this option. If a directory +is specified, the data files are in that directory and named after the +source file name, without its extension. If a file is specified here, +the data files are named after that file, without its extension. If this +option is not supplied, it defaults to the current directory. +.IP "\fB\-u\fR" 4 +.IX Item "-u" .PD 0 -.Ip "\fB\*(--object-directory\fR \fIdirectory\fR" 4 -.IX Item "object-directory directory" +.IP "\fB\-\-unconditional\-branches\fR" 4 +.IX Item "--unconditional-branches" .PD -The directory where the object files live. Gcov will search for \fI.bb\fR, -\&\fI.bbg\fR, and \fI.da\fR files in this directory. +When branch counts are given, include those of unconditional branches. +Unconditional branches are normally not interesting. +.PP +\&\fBgcov\fR should be run with the current directory the same as that +when you invoked the compiler. Otherwise it will not be able to locate +the source files. \fBgcov\fR produces files called +\&\fI\fImangledname\fI.gcov\fR in the current directory. These contain +the coverage information of the source file they correspond to. +One \fI.gcov\fR file is produced for each source file containing code, +which was compiled to produce the data files. The \fImangledname\fR part +of the output file name is usually simply the source file name, but can +be something more complicated if the \fB\-l\fR or \fB\-p\fR options are +given. Refer to those options for details. +.PP +The \fI.gcov\fR files contain the ':' separated fields along with +program source code. The format is +.PP +.Vb 1 +\& <execution_count>:<line_number>:<source line text> +.Ve +.PP +Additional block information may succeed each line, when requested by +command line option. The \fIexecution_count\fR is \fB\-\fR for lines +containing no code and \fB#####\fR for lines which were never +executed. Some lines of information at the start have \fIline_number\fR +of zero. +.PP +When printing percentages, 0% and 100% are only printed when the values +are \fIexactly\fR 0% and 100% respectively. Other values which would +conventionally be rounded to 0% or 100% are instead printed as the +nearest non-boundary value. .PP When using \fBgcov\fR, you must first compile your program with two -special \s-1GCC\s0 options: \fB\-fprofile-arcs \-ftest-coverage\fR. +special \s-1GCC\s0 options: \fB\-fprofile\-arcs \-ftest\-coverage\fR. This tells the compiler to generate additional information needed by gcov (basically a flow graph of the program) and also includes additional code in the object files for generating the extra profiling information needed by gcov. These additional files are placed in the -directory where the source code is located. +directory where the object file is located. .PP Running the program will cause profile output to be generated. For each -source file compiled with \fB\-fprofile-arcs\fR, an accompanying \fI.da\fR -file will be placed in the source directory. +source file compiled with \fB\-fprofile\-arcs\fR, an accompanying +\&\fI.gcda\fR file will be placed in the object file directory. .PP Running \fBgcov\fR with your program's source file names as arguments will now produce a listing of the code along with frequency of execution @@ -292,69 +357,133 @@ is what you see when you use the basic \fBgcov\fR facility: \& $ gcc -fprofile-arcs -ftest-coverage tmp.c \& $ a.out \& $ gcov tmp.c -\& 87.50% of 8 source lines executed in file tmp.c +\& 90.00% of 10 source lines executed in file tmp.c \& Creating tmp.c.gcov. .Ve +.PP The file \fItmp.c.gcov\fR contains output from \fBgcov\fR. Here is a sample: .PP -.Vb 3 -\& main() -\& { -\& 1 int i, total; -.Ve -.Vb 1 -\& 1 total = 0; -.Ve -.Vb 2 -\& 11 for (i = 0; i < 10; i++) -\& 10 total += i; +.Vb 23 +\& -: 0:Source:tmp.c +\& -: 0:Graph:tmp.gcno +\& -: 0:Data:tmp.gcda +\& -: 0:Runs:1 +\& -: 0:Programs:1 +\& -: 1:#include <stdio.h> +\& -: 2: +\& -: 3:int main (void) +\& function main called 1 returned 1 blocks executed 75% +\& 1: 4:{ +\& 1: 5: int i, total; +\& -: 6: +\& 1: 7: total = 0; +\& -: 8: +\& 11: 9: for (i = 0; i < 10; i++) +\& 10: 10: total += i; +\& -: 11: +\& 1: 12: if (total != 45) +\& #####: 13: printf ("Failure\en"); +\& -: 14: else +\& 1: 15: printf ("Success\en"); +\& 1: 16: return 0; +\& -: 17:} .Ve -.Vb 5 -\& 1 if (total != 45) -\& ###### printf ("Failure\en"); -\& else -\& 1 printf ("Success\en"); -\& 1 } +.PP +When you use the \fB\-a\fR option, you will get individual block +counts, and the output looks like this: +.PP +.Vb 30 +\& -: 0:Source:tmp.c +\& -: 0:Graph:tmp.gcno +\& -: 0:Data:tmp.gcda +\& -: 0:Runs:1 +\& -: 0:Programs:1 +\& -: 1:#include <stdio.h> +\& -: 2: +\& -: 3:int main (void) +\& function main called 1 returned 1 blocks executed 75% +\& 1: 4:{ +\& 1: 4-block 0 +\& 1: 5: int i, total; +\& -: 6: +\& 1: 7: total = 0; +\& -: 8: +\& 11: 9: for (i = 0; i < 10; i++) +\& 11: 9-block 0 +\& 10: 10: total += i; +\& 10: 10-block 0 +\& -: 11: +\& 1: 12: if (total != 45) +\& 1: 12-block 0 +\& #####: 13: printf ("Failure\en"); +\& $$$$$: 13-block 0 +\& -: 14: else +\& 1: 15: printf ("Success\en"); +\& 1: 15-block 0 +\& 1: 16: return 0; +\& 1: 16-block 0 +\& -: 17:} .Ve +.PP +In this mode, each basic block is only shown on one line \*(-- the last +line of the block. A multi-line block will only contribute to the +execution count of that last line, and other lines will not be shown +to contain code, unless previous blocks end on those lines. +The total execution count of a line is shown and subsequent lines show +the execution counts for individual blocks that end on that line. After each +block, the branch and call counts of the block will be shown, if the +\&\fB\-b\fR option is given. +.PP +Because of the way \s-1GCC\s0 instruments calls, a call count can be shown +after a line with no individual blocks. +As you can see, line 13 contains a basic block that was not executed. +.PP When you use the \fB\-b\fR option, your output looks like this: .PP .Vb 6 \& $ gcov -b tmp.c -\& 87.50% of 8 source lines executed in file tmp.c -\& 80.00% of 5 branches executed in file tmp.c -\& 80.00% of 5 branches taken at least once in file tmp.c -\& 50.00% of 2 calls executed in file tmp.c +\& 90.00% of 10 source lines executed in file tmp.c +\& 80.00% of 5 branches executed in file tmp.c +\& 80.00% of 5 branches taken at least once in file tmp.c +\& 50.00% of 2 calls executed in file tmp.c \& Creating tmp.c.gcov. .Ve +.PP Here is a sample of a resulting \fItmp.c.gcov\fR file: .PP -.Vb 3 -\& main() -\& { -\& 1 int i, total; -.Ve -.Vb 1 -\& 1 total = 0; -.Ve -.Vb 5 -\& 11 for (i = 0; i < 10; i++) -\& branch 0 taken = 91% -\& branch 1 taken = 100% -\& branch 2 taken = 100% -\& 10 total += i; -.Ve -.Vb 9 -\& 1 if (total != 45) -\& branch 0 taken = 100% -\& ###### printf ("Failure\en"); -\& call 0 never executed -\& branch 1 never executed -\& else -\& 1 printf ("Success\en"); -\& call 0 returns = 100% -\& 1 } +.Vb 29 +\& -: 0:Source:tmp.c +\& -: 0:Graph:tmp.gcno +\& -: 0:Data:tmp.gcda +\& -: 0:Runs:1 +\& -: 0:Programs:1 +\& -: 1:#include <stdio.h> +\& -: 2: +\& -: 3:int main (void) +\& function main called 1 returned 1 blocks executed 75% +\& 1: 4:{ +\& 1: 5: int i, total; +\& -: 6: +\& 1: 7: total = 0; +\& -: 8: +\& 11: 9: for (i = 0; i < 10; i++) +\& branch 0 taken 91% (fallthrough) +\& branch 1 taken 9% +\& 10: 10: total += i; +\& -: 11: +\& 1: 12: if (total != 45) +\& branch 0 taken 0% (fallthrough) +\& branch 1 taken 100% +\& #####: 13: printf ("Failure\en"); +\& call 0 never executed +\& -: 14: else +\& 1: 15: printf ("Success\en"); +\& call 0 called 1 returned 100% +\& 1: 16: return 0; +\& -: 17:} .Ve +.PP For each basic block, a line is printed after the last line of the basic block describing the branch or call that ends the basic block. There can be multiple branches and calls listed for a single source line if there @@ -376,25 +505,25 @@ of times the call was executed will be printed. This will usually be and thus may not return every time they are called. .PP The execution counts are cumulative. If the example program were -executed again without removing the \fI.da\fR file, the count for the +executed again without removing the \fI.gcda\fR file, the count for the number of times each line in the source was executed would be added to -the results of the previous \fIrun\fR\|(s). This is potentially useful in +the results of the previous run(s). This is potentially useful in several ways. For example, it could be used to accumulate data over a number of program runs as part of a test verification suite, or to provide more accurate long-term information over a large number of program runs. .PP -The data in the \fI.da\fR files is saved immediately before the program -exits. For each source file compiled with \fB\-fprofile-arcs\fR, the profiling -code first attempts to read in an existing \fI.da\fR file; if the file -doesn't match the executable (differing number of basic block counts) it -will ignore the contents of the file. It then adds in the new execution -counts and finally writes the data to the file. +The data in the \fI.gcda\fR files is saved immediately before the program +exits. For each source file compiled with \fB\-fprofile\-arcs\fR, the +profiling code first attempts to read in an existing \fI.gcda\fR file; if +the file doesn't match the executable (differing number of basic block +counts) it will ignore the contents of the file. It then adds in the +new execution counts and finally writes the data to the file. .Sh "Using \fBgcov\fP with \s-1GCC\s0 Optimization" .IX Subsection "Using gcov with GCC Optimization" If you plan to use \fBgcov\fR to help optimize your code, you must first compile your program with two special \s-1GCC\s0 options: -\&\fB\-fprofile-arcs \-ftest-coverage\fR. Aside from that, you can use any +\&\fB\-fprofile\-arcs \-ftest\-coverage\fR. Aside from that, you can use any other \s-1GCC\s0 options; but if you want to prove that every single line in your program was executed, you should not compile with optimization at the same time. On some machines the optimizer can eliminate some @@ -407,6 +536,7 @@ like this: \& else \& c = 0; .Ve +.PP can be compiled into one instruction on some machines. In this case, there is no way for \fBgcov\fR to calculate separate execution counts for each line because there isn't separate code for each line. Hence @@ -414,25 +544,48 @@ the \fBgcov\fR output looks like this if you compiled the program with optimization: .PP .Vb 4 -\& 100 if (a != b) -\& 100 c = 1; -\& 100 else -\& 100 c = 0; +\& 100: 12:if (a != b) +\& 100: 13: c = 1; +\& 100: 14:else +\& 100: 15: c = 0; .Ve +.PP The output shows that this block of code, combined by optimization, executed 100 times. In one sense this result is correct, because there was only one instruction representing all four of these lines. However, the output does not indicate how many times the result was 0 and how many times the result was 1. +.PP +Inlineable functions can create unexpected line counts. Line counts are +shown for the source code of the inlineable function, but what is shown +depends on where the function is inlined, or if it is not inlined at all. +.PP +If the function is not inlined, the compiler must emit an out of line +copy of the function, in any object file that needs it. If +\&\fIfileA.o\fR and \fIfileB.o\fR both contain out of line bodies of a +particular inlineable function, they will also both contain coverage +counts for that function. When \fIfileA.o\fR and \fIfileB.o\fR are +linked together, the linker will, on many systems, select one of those +out of line bodies for all calls to that function, and remove or ignore +the other. Unfortunately, it will not remove the coverage counters for +the unused function body. Hence when instrumented, all but one use of +that function will show zero counts. +.PP +If the function is inlined in several places, the block structure in +each location might not be the same. For instance, a condition might +now be calculable at compile time in some instances. Because the +coverage of all the uses of the inline function will be shown for the +same source lines, the line counts themselves might seem inconsistent. .SH "SEE ALSO" .IX Header "SEE ALSO" -\&\fIgpl\fR\|(7), \fIgfdl\fR\|(7), \fIfsf-funding\fR\|(7), \fIgcc\fR\|(1) and the Info entry for \fIgcc\fR. +\&\fIgpl\fR\|(7), \fIgfdl\fR\|(7), \fIfsf\-funding\fR\|(7), \fIgcc\fR\|(1) and the Info entry for \fIgcc\fR. .SH "COPYRIGHT" .IX Header "COPYRIGHT" -Copyright (c) 1996, 1997, 1999, 2000, 2001 Free Software Foundation, Inc. +Copyright (c) 1996, 1997, 1999, 2000, 2001, 2002, 2003 +Free Software Foundation, Inc. .PP Permission is granted to copy, distribute and/or modify this document -under the terms of the \s-1GNU\s0 Free Documentation License, Version 1.1 or +under the terms of the \s-1GNU\s0 Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with the Invariant Sections being ``\s-1GNU\s0 General Public License'' and ``Funding Free Software'', the Front-Cover texts being (a) (see below), and with @@ -444,6 +597,7 @@ included in the \fIgfdl\fR\|(7) man page. .Vb 1 \& A GNU Manual .Ve +.PP (b) The \s-1FSF\s0's Back-Cover Text is: .PP .Vb 3 |