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Diffstat (limited to 'contrib/gcc/doc/tm.texi')
-rw-r--r-- | contrib/gcc/doc/tm.texi | 4254 |
1 files changed, 2158 insertions, 2096 deletions
diff --git a/contrib/gcc/doc/tm.texi b/contrib/gcc/doc/tm.texi index 9a71173..03c1c4e 100644 --- a/contrib/gcc/doc/tm.texi +++ b/contrib/gcc/doc/tm.texi @@ -1,5 +1,5 @@ -@c Copyright (C) 1988,1989,1992,1993,1994,1995,1996,1997,1998,1999,2000,2001,2002,2003 -@c Free Software Foundation, Inc. +@c Copyright (C) 1988,1989,1992,1993,1994,1995,1996,1997,1998,1999,2000,2001, +@c 2002, 2003, 2004 Free Software Foundation, Inc. @c This is part of the GCC manual. @c For copying conditions, see the file gcc.texi. @@ -50,6 +50,7 @@ through the macros defined in the @file{.h} file. * Mode Switching:: Insertion of mode-switching instructions. * Target Attributes:: Defining target-specific uses of @code{__attribute__}. * MIPS Coprocessors:: MIPS coprocessor support and how to customize it. +* PCH Target:: Validity checking for precompiled headers. * Misc:: Everything else. @end menu @@ -93,9 +94,7 @@ from being defined in the @file{.h} file to being part of the @c prevent bad page break with this line You can control the compilation driver. -@table @code -@findex SWITCH_TAKES_ARG -@item SWITCH_TAKES_ARG (@var{char}) +@defmac SWITCH_TAKES_ARG (@var{char}) A C expression which determines whether the option @option{-@var{char}} takes arguments. The value should be the number of arguments that option takes--zero, for many options. @@ -106,9 +105,9 @@ properly. You need not define @code{SWITCH_TAKES_ARG} unless you wish to add additional options which take arguments. Any redefinition should call @code{DEFAULT_SWITCH_TAKES_ARG} and then check for additional options. +@end defmac -@findex WORD_SWITCH_TAKES_ARG -@item WORD_SWITCH_TAKES_ARG (@var{name}) +@defmac WORD_SWITCH_TAKES_ARG (@var{name}) A C expression which determines whether the option @option{-@var{name}} takes arguments. The value should be the number of arguments that option takes--zero, for many options. This macro rather than @@ -120,9 +119,9 @@ properly. You need not define @code{WORD_SWITCH_TAKES_ARG} unless you wish to add additional options which take arguments. Any redefinition should call @code{DEFAULT_WORD_SWITCH_TAKES_ARG} and then check for additional options. +@end defmac -@findex SWITCH_CURTAILS_COMPILATION -@item SWITCH_CURTAILS_COMPILATION (@var{char}) +@defmac SWITCH_CURTAILS_COMPILATION (@var{char}) A C expression which determines whether the option @option{-@var{char}} stops compilation before the generation of an executable. The value is boolean, nonzero if the option does stop an executable from being @@ -135,16 +134,16 @@ options properly. You need not define options which affect the generation of an executable. Any redefinition should call @code{DEFAULT_SWITCH_CURTAILS_COMPILATION} and then check for additional options. +@end defmac -@findex SWITCHES_NEED_SPACES -@item SWITCHES_NEED_SPACES +@defmac SWITCHES_NEED_SPACES A string-valued C expression which enumerates the options for which the linker needs a space between the option and its argument. If this macro is not defined, the default value is @code{""}. +@end defmac -@findex TARGET_OPTION_TRANSLATE_TABLE -@item TARGET_OPTION_TRANSLATE_TABLE +@defmac TARGET_OPTION_TRANSLATE_TABLE If defined, a list of pairs of strings, the first of which is a potential command line target to the @file{gcc} driver program, and the second of which is a space-separated (tabs and other whitespace are not @@ -162,40 +161,60 @@ multilibs. Example nonsensical definition, where @code{-malt-abi}, @{ "-fast", "-march=fast-foo -malt-abi -I/usr/fast-foo" @}, \ @{ "-compat", "-EB -malign=4 -mspoo" @} @end smallexample +@end defmac -@findex DRIVER_SELF_SPECS -@item DRIVER_SELF_SPECS +@defmac DRIVER_SELF_SPECS A list of specs for the driver itself. It should be a suitable initializer for an array of strings, with no surrounding braces. -The driver applies these specs to its own command line before choosing -the multilib directory or running any subcommands. It applies them in -the order given, so each spec can depend on the options added by -earlier ones. It is also possible to remove options using -@samp{%<@var{option}} in the usual way. +The driver applies these specs to its own command line between loading +default @file{specs} files (but not command-line specified ones) and +choosing the multilib directory or running any subcommands. It +applies them in the order given, so each spec can depend on the +options added by earlier ones. It is also possible to remove options +using @samp{%<@var{option}} in the usual way. This macro can be useful when a port has several interdependent target options. It provides a way of standardizing the command line so that the other specs are easier to write. Do not define this macro if it does not need to do anything. +@end defmac + +@defmac OPTION_DEFAULT_SPECS +A list of specs used to support configure-time default options (i.e.@: +@option{--with} options) in the driver. It should be a suitable initializer +for an array of structures, each containing two strings, without the +outermost pair of surrounding braces. + +The first item in the pair is the name of the default. This must match +the code in @file{config.gcc} for the target. The second item is a spec +to apply if a default with this name was specified. The string +@samp{%(VALUE)} in the spec will be replaced by the value of the default +everywhere it occurs. + +The driver will apply these specs to its own command line between loading +default @file{specs} files and processing @code{DRIVER_SELF_SPECS}, using +the same mechanism as @code{DRIVER_SELF_SPECS}. + +Do not define this macro if it does not need to do anything. +@end defmac -@findex CPP_SPEC -@item CPP_SPEC +@defmac CPP_SPEC A C string constant that tells the GCC driver program options to pass to CPP@. It can also specify how to translate options you give to GCC into options for GCC to pass to the CPP@. Do not define this macro if it does not need to do anything. +@end defmac -@findex CPLUSPLUS_CPP_SPEC -@item CPLUSPLUS_CPP_SPEC +@defmac CPLUSPLUS_CPP_SPEC This macro is just like @code{CPP_SPEC}, but is used for C++, rather than C@. If you do not define this macro, then the value of @code{CPP_SPEC} (if any) will be used instead. +@end defmac -@findex CC1_SPEC -@item CC1_SPEC +@defmac CC1_SPEC A C string constant that tells the GCC driver program options to pass to @code{cc1}, @code{cc1plus}, @code{f771}, and the other language front ends. @@ -203,9 +222,9 @@ It can also specify how to translate options you give to GCC into options for GCC to pass to front ends. Do not define this macro if it does not need to do anything. +@end defmac -@findex CC1PLUS_SPEC -@item CC1PLUS_SPEC +@defmac CC1PLUS_SPEC A C string constant that tells the GCC driver program options to pass to @code{cc1plus}. It can also specify how to translate options you give to GCC into options for GCC to pass to the @code{cc1plus}. @@ -214,44 +233,57 @@ Do not define this macro if it does not need to do anything. Note that everything defined in CC1_SPEC is already passed to @code{cc1plus} so there is no need to duplicate the contents of CC1_SPEC in CC1PLUS_SPEC@. +@end defmac -@findex ASM_SPEC -@item ASM_SPEC +@defmac ASM_SPEC A C string constant that tells the GCC driver program options to pass to the assembler. It can also specify how to translate options you give to GCC into options for GCC to pass to the assembler. See the file @file{sun3.h} for an example of this. Do not define this macro if it does not need to do anything. +@end defmac -@findex ASM_FINAL_SPEC -@item ASM_FINAL_SPEC +@defmac ASM_FINAL_SPEC A C string constant that tells the GCC driver program how to run any programs which cleanup after the normal assembler. Normally, this is not needed. See the file @file{mips.h} for an example of this. Do not define this macro if it does not need to do anything. +@end defmac -@findex LINK_SPEC -@item LINK_SPEC +@defmac AS_NEEDS_DASH_FOR_PIPED_INPUT +Define this macro, with no value, if the driver should give the assembler +an argument consisting of a single dash, @option{-}, to instruct it to +read from its standard input (which will be a pipe connected to the +output of the compiler proper). This argument is given after any +@option{-o} option specifying the name of the output file. + +If you do not define this macro, the assembler is assumed to read its +standard input if given no non-option arguments. If your assembler +cannot read standard input at all, use a @samp{%@{pipe:%e@}} construct; +see @file{mips.h} for instance. +@end defmac + +@defmac LINK_SPEC A C string constant that tells the GCC driver program options to pass to the linker. It can also specify how to translate options you give to GCC into options for GCC to pass to the linker. Do not define this macro if it does not need to do anything. +@end defmac -@findex LIB_SPEC -@item LIB_SPEC +@defmac LIB_SPEC Another C string constant used much like @code{LINK_SPEC}. The difference between the two is that @code{LIB_SPEC} is used at the end of the command given to the linker. If this macro is not defined, a default is provided that loads the standard C library from the usual place. See @file{gcc.c}. +@end defmac -@findex LIBGCC_SPEC -@item LIBGCC_SPEC +@defmac LIBGCC_SPEC Another C string constant that tells the GCC driver program how and when to place a reference to @file{libgcc.a} into the linker command line. This constant is placed both before and after @@ -259,26 +291,26 @@ the value of @code{LIB_SPEC}. If this macro is not defined, the GCC driver provides a default that passes the string @option{-lgcc} to the linker. +@end defmac -@findex STARTFILE_SPEC -@item STARTFILE_SPEC +@defmac STARTFILE_SPEC Another C string constant used much like @code{LINK_SPEC}. The difference between the two is that @code{STARTFILE_SPEC} is used at the very beginning of the command given to the linker. If this macro is not defined, a default is provided that loads the standard C startup file from the usual place. See @file{gcc.c}. +@end defmac -@findex ENDFILE_SPEC -@item ENDFILE_SPEC +@defmac ENDFILE_SPEC Another C string constant used much like @code{LINK_SPEC}. The difference between the two is that @code{ENDFILE_SPEC} is used at the very end of the command given to the linker. Do not define this macro if it does not need to do anything. +@end defmac -@findex THREAD_MODEL_SPEC -@item THREAD_MODEL_SPEC +@defmac THREAD_MODEL_SPEC GCC @code{-v} will print the thread model GCC was configured to use. However, this doesn't work on platforms that are multilibbed on thread models, such as AIX 4.3. On such platforms, define @@ -286,9 +318,22 @@ models, such as AIX 4.3. On such platforms, define blanks that names one of the recognized thread models. @code{%*}, the default value of this macro, will expand to the value of @code{thread_file} set in @file{config.gcc}. +@end defmac + +@defmac SYSROOT_SUFFIX_SPEC +Define this macro to add a suffix to the target sysroot when GCC is +configured with a sysroot. This will cause GCC to search for usr/lib, +et al, within sysroot+suffix. +@end defmac -@findex EXTRA_SPECS -@item EXTRA_SPECS +@defmac SYSROOT_HEADERS_SUFFIX_SPEC +Define this macro to add a headers_suffix to the target sysroot when +GCC is configured with a sysroot. This will cause GCC to pass the +updated sysroot+headers_suffix to CPP, causing it to search for +usr/include, et al, within sysroot+headers_suffix. +@end defmac + +@defmac EXTRA_SPECS Define this macro to provide additional specifications to put in the @file{specs} file that can be used in various specifications like @code{CC1_SPEC}. @@ -311,20 +356,20 @@ used. The @file{config/rs6000/rs6000.h} target file defines: -@example +@smallexample #define EXTRA_SPECS \ @{ "cpp_sysv_default", CPP_SYSV_DEFAULT @}, #define CPP_SYS_DEFAULT "" -@end example +@end smallexample The @file{config/rs6000/sysv.h} target file defines: @smallexample #undef CPP_SPEC #define CPP_SPEC \ "%@{posix: -D_POSIX_SOURCE @} \ -%@{mcall-sysv: -D_CALL_SYSV @} %@{mcall-aix: -D_CALL_AIX @} \ -%@{!mcall-sysv: %@{!mcall-aix: %(cpp_sysv_default) @}@} \ +%@{mcall-sysv: -D_CALL_SYSV @} \ +%@{!mcall-sysv: %(cpp_sysv_default) @} \ %@{msoft-float: -D_SOFT_FLOAT@} %@{mcpu=403: -D_SOFT_FLOAT@}" #undef CPP_SYSV_DEFAULT @@ -338,30 +383,30 @@ while the @file{config/rs6000/eabiaix.h} target file defines #undef CPP_SYSV_DEFAULT #define CPP_SYSV_DEFAULT "-D_CALL_AIX" @end smallexample +@end defmac -@findex LINK_LIBGCC_SPECIAL -@item LINK_LIBGCC_SPECIAL +@defmac LINK_LIBGCC_SPECIAL Define this macro if the driver program should find the library @file{libgcc.a} itself and should not pass @option{-L} options to the linker. If you do not define this macro, the driver program will pass the argument @option{-lgcc} to tell the linker to do the search and will pass @option{-L} options to it. +@end defmac -@findex LINK_LIBGCC_SPECIAL_1 -@item LINK_LIBGCC_SPECIAL_1 +@defmac LINK_LIBGCC_SPECIAL_1 Define this macro if the driver program should find the library @file{libgcc.a}. If you do not define this macro, the driver program will pass the argument @option{-lgcc} to tell the linker to do the search. This macro is similar to @code{LINK_LIBGCC_SPECIAL}, except that it does not affect @option{-L} options. +@end defmac -@findex LINK_GCC_C_SEQUENCE_SPEC -@item LINK_GCC_C_SEQUENCE_SPEC +@defmac LINK_GCC_C_SEQUENCE_SPEC The sequence in which libgcc and libc are specified to the linker. By default this is @code{%G %L %G}. +@end defmac -@findex LINK_COMMAND_SPEC -@item LINK_COMMAND_SPEC +@defmac LINK_COMMAND_SPEC A C string constant giving the complete command line need to execute the linker. When you do this, you will need to update your port each time a change is made to the link command line within @file{gcc.c}. Therefore, @@ -369,15 +414,15 @@ define this macro only if you need to completely redefine the command line for invoking the linker and there is no other way to accomplish the effect you need. Overriding this macro may be avoidable by overriding @code{LINK_GCC_C_SEQUENCE_SPEC} instead. +@end defmac -@findex LINK_ELIMINATE_DUPLICATE_LDIRECTORIES -@item LINK_ELIMINATE_DUPLICATE_LDIRECTORIES +@defmac LINK_ELIMINATE_DUPLICATE_LDIRECTORIES A nonzero value causes @command{collect2} to remove duplicate @option{-L@var{directory}} search directories from linking commands. Do not give it a nonzero value if removing duplicate search directories changes the linker's semantics. +@end defmac -@findex MULTILIB_DEFAULTS -@item MULTILIB_DEFAULTS +@defmac MULTILIB_DEFAULTS Define this macro as a C expression for the initializer of an array of string to tell the driver program which options are defaults for this target and thus do not need to be handled specially when using @@ -387,55 +432,51 @@ Do not define this macro if @code{MULTILIB_OPTIONS} is not defined in the target makefile fragment or if none of the options listed in @code{MULTILIB_OPTIONS} are set by default. @xref{Target Fragment}. +@end defmac -@findex RELATIVE_PREFIX_NOT_LINKDIR -@item RELATIVE_PREFIX_NOT_LINKDIR +@defmac RELATIVE_PREFIX_NOT_LINKDIR Define this macro to tell @command{gcc} that it should only translate a @option{-B} prefix into a @option{-L} linker option if the prefix indicates an absolute file name. +@end defmac -@findex STANDARD_EXEC_PREFIX -@item STANDARD_EXEC_PREFIX -Define this macro as a C string constant if you wish to override the -standard choice of @file{/usr/local/lib/gcc-lib/} as the default prefix to -try when searching for the executable files of the compiler. - -@findex MD_EXEC_PREFIX -@item MD_EXEC_PREFIX +@defmac MD_EXEC_PREFIX If defined, this macro is an additional prefix to try after @code{STANDARD_EXEC_PREFIX}. @code{MD_EXEC_PREFIX} is not searched when the @option{-b} option is used, or the compiler is built as a cross compiler. If you define @code{MD_EXEC_PREFIX}, then be sure to add it to the list of directories used to find the assembler in @file{configure.in}. +@end defmac -@findex STANDARD_STARTFILE_PREFIX -@item STANDARD_STARTFILE_PREFIX +@defmac STANDARD_STARTFILE_PREFIX Define this macro as a C string constant if you wish to override the -standard choice of @file{/usr/local/lib/} as the default prefix to +standard choice of @code{libdir} as the default prefix to try when searching for startup files such as @file{crt0.o}. +@code{STANDARD_STARTFILE_PREFIX} is not searched when the compiler +is built as a cross compiler. +@end defmac -@findex MD_STARTFILE_PREFIX -@item MD_STARTFILE_PREFIX +@defmac MD_STARTFILE_PREFIX If defined, this macro supplies an additional prefix to try after the standard prefixes. @code{MD_EXEC_PREFIX} is not searched when the @option{-b} option is used, or when the compiler is built as a cross compiler. +@end defmac -@findex MD_STARTFILE_PREFIX_1 -@item MD_STARTFILE_PREFIX_1 +@defmac MD_STARTFILE_PREFIX_1 If defined, this macro supplies yet another prefix to try after the standard prefixes. It is not searched when the @option{-b} option is used, or when the compiler is built as a cross compiler. +@end defmac -@findex INIT_ENVIRONMENT -@item INIT_ENVIRONMENT +@defmac INIT_ENVIRONMENT Define this macro as a C string constant if you wish to set environment variables for programs called by the driver, such as the assembler and loader. The driver passes the value of this macro to @code{putenv} to initialize the necessary environment variables. +@end defmac -@findex LOCAL_INCLUDE_DIR -@item LOCAL_INCLUDE_DIR +@defmac LOCAL_INCLUDE_DIR Define this macro as a C string constant if you wish to override the standard choice of @file{/usr/local/include} as the default prefix to try when searching for local header files. @code{LOCAL_INCLUDE_DIR} @@ -443,11 +484,11 @@ comes before @code{SYSTEM_INCLUDE_DIR} in the search order. Cross compilers do not search either @file{/usr/local/include} or its replacement. +@end defmac -@findex MODIFY_TARGET_NAME -@item MODIFY_TARGET_NAME -Define this macro if you with to define command-line switches that modify the -default target name +@defmac MODIFY_TARGET_NAME +Define this macro if you wish to define command-line switches that +modify the default target name. For each switch, you can include a string to be appended to the first part of the configuration name or a string to be deleted from the @@ -468,10 +509,9 @@ code @{ @{ "-32", DELETE, "64"@}, \ @{"-64", ADD, "64"@}@} @end smallexample +@end defmac - -@findex SYSTEM_INCLUDE_DIR -@item SYSTEM_INCLUDE_DIR +@defmac SYSTEM_INCLUDE_DIR Define this macro as a C string constant if you wish to specify a system-specific directory to search for header files before the standard directory. @code{SYSTEM_INCLUDE_DIR} comes before @@ -479,24 +519,24 @@ directory. @code{SYSTEM_INCLUDE_DIR} comes before Cross compilers do not use this macro and do not search the directory specified. +@end defmac -@findex STANDARD_INCLUDE_DIR -@item STANDARD_INCLUDE_DIR +@defmac STANDARD_INCLUDE_DIR Define this macro as a C string constant if you wish to override the standard choice of @file{/usr/include} as the default prefix to try when searching for header files. -Cross compilers do not use this macro and do not search either +Cross compilers ignore this macro and do not search either @file{/usr/include} or its replacement. +@end defmac -@findex STANDARD_INCLUDE_COMPONENT -@item STANDARD_INCLUDE_COMPONENT +@defmac STANDARD_INCLUDE_COMPONENT The ``component'' corresponding to @code{STANDARD_INCLUDE_DIR}. See @code{INCLUDE_DEFAULTS}, below, for the description of components. If you do not define this macro, no component is used. +@end defmac -@findex INCLUDE_DEFAULTS -@item INCLUDE_DEFAULTS +@defmac INCLUDE_DEFAULTS Define this macro if you wish to override the entire default search path for include files. For a native compiler, the default search path usually consists of @code{GCC_INCLUDE_DIR}, @code{LOCAL_INCLUDE_DIR}, @@ -515,13 +555,13 @@ wrapped in @code{extern @samp{C}} when compiling C++. Mark the end of the array with a null element. The component name denotes what GNU package the include file is part of, -if any, in all upper-case letters. For example, it might be @samp{GCC} +if any, in all uppercase letters. For example, it might be @samp{GCC} or @samp{BINUTILS}. If the package is part of a vendor-supplied operating system, code the component name as @samp{0}. For example, here is the definition used for VAX/VMS: -@example +@smallexample #define INCLUDE_DEFAULTS \ @{ \ @{ "GNU_GXX_INCLUDE:", "G++", 1, 1@}, \ @@ -530,8 +570,8 @@ For example, here is the definition used for VAX/VMS: @{ ".", 0, 0, 0@}, \ @{ 0, 0, 0, 0@} \ @} -@end example -@end table +@end smallexample +@end defmac Here is the order of prefixes tried for exec files: @@ -599,13 +639,11 @@ The macro @code{STANDARD_STARTFILE_PREFIX}. @c prevent bad page break with this line Here are run-time target specifications. -@table @code -@findex TARGET_CPU_CPP_BUILTINS -@item TARGET_CPU_CPP_BUILTINS() +@defmac TARGET_CPU_CPP_BUILTINS () This function-like macro expands to a block of code that defines built-in preprocessor macros and assertions for the target cpu, using the functions @code{builtin_define}, @code{builtin_define_std} and -@code{builtin_assert} defined in @file{c-common.c}. When the front end +@code{builtin_assert}. When the front end calls this macro it provides a trailing semicolon, and since it has finished command line option processing your code can use those results freely. @@ -635,48 +673,28 @@ to check for that first. If you need to check for strict ANSI, the variable @code{flag_iso} can be used. The function-like macro @code{preprocessing_trad_p()} can be used to check for traditional preprocessing. +@end defmac -With @code{TARGET_OS_CPP_BUILTINS} this macro obsoletes the -@code{CPP_PREDEFINES} target macro. - -@findex TARGET_OS_CPP_BUILTINS -@item TARGET_OS_CPP_BUILTINS() +@defmac TARGET_OS_CPP_BUILTINS () Similarly to @code{TARGET_CPU_CPP_BUILTINS} but this macro is optional and is used for the target operating system instead. +@end defmac -With @code{TARGET_CPU_CPP_BUILTINS} this macro obsoletes the -@code{CPP_PREDEFINES} target macro. - -@findex CPP_PREDEFINES -@item CPP_PREDEFINES -Define this to be a string constant containing @option{-D} options to -define the predefined macros that identify this machine and system. -These macros will be predefined unless the @option{-ansi} option (or a -@option{-std} option for strict ISO C conformance) is specified. - -In addition, a parallel set of macros are predefined, whose names are -made by appending @samp{__} at the beginning and at the end. These -@samp{__} macros are permitted by the ISO standard, so they are -predefined regardless of whether @option{-ansi} or a @option{-std} option -is specified. - -For example, on the Sun, one can use the following value: - -@smallexample -"-Dmc68000 -Dsun -Dunix" -@end smallexample - -The result is to define the macros @code{__mc68000__}, @code{__sun__} -and @code{__unix__} unconditionally, and the macros @code{mc68000}, -@code{sun} and @code{unix} provided @option{-ansi} is not specified. +@defmac TARGET_OBJFMT_CPP_BUILTINS () +Similarly to @code{TARGET_CPU_CPP_BUILTINS} but this macro is optional +and is used for the target object format. @file{elfos.h} uses this +macro to define @code{__ELF__}, so you probably do not need to define +it yourself. +@end defmac -@findex extern int target_flags -@item extern int target_flags; +@deftypevar {extern int} target_flags This declaration should be present. +@end deftypevar @cindex optional hardware or system features @cindex features, optional, in system conventions -@item TARGET_@dots{} + +@defmac TARGET_@var{featurename} This series of macros is to allow compiler command arguments to enable or disable the use of optional features of the target machine. For example, one machine description serves both the 68000 and @@ -687,14 +705,14 @@ by means of a macro @code{TARGET_68020} that tests a bit in Define a macro @code{TARGET_@var{featurename}} for each such option. Its definition should test a bit in @code{target_flags}. It is -recommended that a helper macro @code{TARGET_MASK_@var{featurename}} +recommended that a helper macro @code{MASK_@var{featurename}} is defined for each bit-value to test, and used in @code{TARGET_@var{featurename}} and @code{TARGET_SWITCHES}. For example: @smallexample #define TARGET_MASK_68020 1 -#define TARGET_68020 (target_flags & TARGET_MASK_68020) +#define TARGET_68020 (target_flags & MASK_68020) @end smallexample One place where these macros are used is in the condition-expressions @@ -702,9 +720,9 @@ of instruction patterns. Note how @code{TARGET_68020} appears frequently in the 68000 machine description file, @file{m68k.md}. Another place they are used is in the definitions of the other macros in the @file{@var{machine}.h} file. +@end defmac -@findex TARGET_SWITCHES -@item TARGET_SWITCHES +@defmac TARGET_SWITCHES This macro defines names of command options to set and clear bits in @code{target_flags}. Its definition is an initializer with a subgrouping for each command option. @@ -735,29 +753,39 @@ with opposite meanings, and picks the latter as the default: @smallexample #define TARGET_SWITCHES \ - @{ @{ "68020", TARGET_MASK_68020, "" @}, \ - @{ "68000", -TARGET_MASK_68020, \ + @{ @{ "68020", MASK_68020, "" @}, \ + @{ "68000", -MASK_68020, \ N_("Compile for the 68000") @}, \ - @{ "", TARGET_MASK_68020, "" @}@} + @{ "", MASK_68020, "" @}, \ + @} @end smallexample +@end defmac -@findex TARGET_OPTIONS -@item TARGET_OPTIONS +@defmac TARGET_OPTIONS This macro is similar to @code{TARGET_SWITCHES} but defines names of command options that have values. Its definition is an initializer with a subgrouping for each command option. -Each subgrouping contains a string constant, that defines the fixed part -of the option name, the address of a variable, and a description string. -Non-empty description strings should be marked with @code{N_(@dots{})} for -@command{xgettext}. Please do not mark empty strings because the empty -string is reserved by GNU gettext. @code{gettext("")} returns the header entry -of the message catalog with meta information, not the empty string. +Each subgrouping contains a string constant, that defines the option +name, the address of a variable, a description string, and a value. +Non-empty description strings should be marked with @code{N_(@dots{})} +for @command{xgettext}. Please do not mark empty strings because the +empty string is reserved by GNU gettext. @code{gettext("")} returns the +header entry of the message catalog with meta information, not the empty +string. + +If the value listed in the table is @code{NULL}, then the variable, type +@code{char *}, is set to the variable part of the given option if the +fixed part matches. In other words, if the first part of the option +matches what's in the table, the variable will be set to point to the +rest of the option. This allows the user to specify a value for that +option. The actual option name is made by appending @samp{-m} to the +specified name. Again, each option should also be documented in +@file{invoke.texi}. -The variable, type @code{char *}, is set to the variable part of the -given option if the fixed part matches. The actual option name is made -by appending @samp{-m} to the specified name. Again, each option should -also be documented in @file{invoke.texi}. +If the value listed in the table is non-@code{NULL}, then the option +must match the option in the table exactly (with @samp{-m}), and the +variable is set to point to the value listed in the table. Here is an example which defines @option{-mshort-data-@var{number}}. If the given option is @option{-mshort-data-512}, the variable @code{m88k_short_data} @@ -767,11 +795,42 @@ will be set to the string @code{"512"}. extern char *m88k_short_data; #define TARGET_OPTIONS \ @{ @{ "short-data-", &m88k_short_data, \ - N_("Specify the size of the short data section") @} @} + N_("Specify the size of the short data section"), 0 @} @} +@end smallexample + +Here is a variant of the above that allows the user to also specify +just @option{-mshort-data} where a default of @code{"64"} is used. + +@smallexample +extern char *m88k_short_data; +#define TARGET_OPTIONS \ + @{ @{ "short-data-", &m88k_short_data, \ + N_("Specify the size of the short data section"), 0 @} \ + @{ "short-data", &m88k_short_data, "", "64" @}, + @} +@end smallexample + +Here is an example which defines @option{-mno-alu}, @option{-malu1}, and +@option{-malu2} as a three-state switch, along with suitable macros for +checking the state of the option (documentation is elided for brevity). + +@smallexample +[chip.c] +char *chip_alu = ""; /* Specify default here. */ + +[chip.h] +extern char *chip_alu; +#define TARGET_OPTIONS \ + @{ @{ "no-alu", &chip_alu, "", "" @}, \ + @{ "alu1", &chip_alu, "", "1" @}, \ + @{ "alu2", &chip_alu, "", "2" @}, @} +#define TARGET_ALU (chip_alu[0] != '\0') +#define TARGET_ALU1 (chip_alu[0] == '1') +#define TARGET_ALU2 (chip_alu[0] == '2') @end smallexample +@end defmac -@findex TARGET_VERSION -@item TARGET_VERSION +@defmac TARGET_VERSION This macro is a C statement to print on @code{stderr} a string describing the particular machine description choice. Every machine description should define @code{TARGET_VERSION}. For example: @@ -785,9 +844,9 @@ description should define @code{TARGET_VERSION}. For example: fprintf (stderr, " (68k, MIT syntax)"); #endif @end smallexample +@end defmac -@findex OVERRIDE_OPTIONS -@item OVERRIDE_OPTIONS +@defmac OVERRIDE_OPTIONS Sometimes certain combinations of command options do not make sense on a particular target machine. You can define a macro @code{OVERRIDE_OPTIONS} to take account of this. This macro, if @@ -796,9 +855,9 @@ parsed. Don't use this macro to turn on various extra optimizations for @option{-O}. That is what @code{OPTIMIZATION_OPTIONS} is for. +@end defmac -@findex OPTIMIZATION_OPTIONS -@item OPTIMIZATION_OPTIONS (@var{level}, @var{size}) +@defmac OPTIMIZATION_OPTIONS (@var{level}, @var{size}) Some machines may desire to change what optimizations are performed for various optimization levels. This macro, if defined, is executed once just after the optimization level is determined and before the remainder @@ -818,13 +877,13 @@ machine-specific optimizations. @strong{Do not examine @code{write_symbols} in this macro!} The debugging options are not supposed to alter the generated code. +@end defmac -@findex CAN_DEBUG_WITHOUT_FP -@item CAN_DEBUG_WITHOUT_FP +@defmac CAN_DEBUG_WITHOUT_FP Define this macro if debugging can be performed even without a frame pointer. If this macro is defined, GCC will turn on the @option{-fomit-frame-pointer} option whenever @option{-O} is specified. -@end table +@end defmac @node Per-Function Data @section Defining data structures for per-function information. @@ -863,30 +922,24 @@ the saving and restoring of the target specific information. Since the single data area approach is no longer used, these pointers are no longer supported. -The macro and function pointers are described below. - -@table @code -@findex INIT_EXPANDERS -@item INIT_EXPANDERS +@defmac INIT_EXPANDERS Macro called to initialize any target specific information. This macro is called once per function, before generation of any RTL has begun. The intention of this macro is to allow the initialization of the -function pointers below. +function pointer @code{init_machine_status}. +@end defmac -@findex init_machine_status -@item init_machine_status -This is a @code{void (*)(struct function *)} function pointer. If this -pointer is non-@code{NULL} it will be called once per function, before function -compilation starts, in order to allow the target to perform any target -specific initialization of the @code{struct function} structure. It is -intended that this would be used to initialize the @code{machine} of -that structure. +@deftypevar {void (*)(struct function *)} init_machine_status +If this function pointer is non-@code{NULL} it will be called once per +function, before function compilation starts, in order to allow the +target to perform any target specific initialization of the +@code{struct function} structure. It is intended that this would be +used to initialize the @code{machine} of that structure. @code{struct machine_function} structures are expected to be freed by GC. Generally, any memory that they reference must be allocated by using @code{ggc_alloc}, including the structure itself. - -@end table +@end deftypevar @node Storage Layout @section Storage Layout @@ -897,9 +950,7 @@ alignments measured in bits do not need to be constant. They can be C expressions that refer to static variables, such as the @code{target_flags}. @xref{Run-time Target}. -@table @code -@findex BITS_BIG_ENDIAN -@item BITS_BIG_ENDIAN +@defmac BITS_BIG_ENDIAN Define this macro to have the value 1 if the most significant bit in a byte has the lowest number; otherwise define it to have the value zero. This means that bit-field instructions count from the most significant @@ -909,29 +960,29 @@ macro need not be a constant. This macro does not affect the way structure fields are packed into bytes or words; that is controlled by @code{BYTES_BIG_ENDIAN}. +@end defmac -@findex BYTES_BIG_ENDIAN -@item BYTES_BIG_ENDIAN +@defmac BYTES_BIG_ENDIAN Define this macro to have the value 1 if the most significant byte in a word has the lowest number. This macro need not be a constant. +@end defmac -@findex WORDS_BIG_ENDIAN -@item WORDS_BIG_ENDIAN +@defmac WORDS_BIG_ENDIAN Define this macro to have the value 1 if, in a multiword object, the most significant word has the lowest number. This applies to both memory locations and registers; GCC fundamentally assumes that the order of words in memory is the same as the order in registers. This macro need not be a constant. +@end defmac -@findex LIBGCC2_WORDS_BIG_ENDIAN -@item LIBGCC2_WORDS_BIG_ENDIAN +@defmac LIBGCC2_WORDS_BIG_ENDIAN Define this macro if @code{WORDS_BIG_ENDIAN} is not constant. This must be a constant value with the same meaning as @code{WORDS_BIG_ENDIAN}, which will be used only when compiling @file{libgcc2.c}. Typically the value will be set based on preprocessor defines. +@end defmac -@findex FLOAT_WORDS_BIG_ENDIAN -@item FLOAT_WORDS_BIG_ENDIAN +@defmac FLOAT_WORDS_BIG_ENDIAN Define this macro to have the value 1 if @code{DFmode}, @code{XFmode} or @code{TFmode} floating point numbers are stored in memory with the word containing the sign bit at the lowest address; otherwise define it to @@ -939,42 +990,42 @@ have the value 0. This macro need not be a constant. You need not define this macro if the ordering is the same as for multi-word integers. +@end defmac -@findex BITS_PER_UNIT -@item BITS_PER_UNIT +@defmac BITS_PER_UNIT Define this macro to be the number of bits in an addressable storage unit (byte). If you do not define this macro the default is 8. +@end defmac -@findex BITS_PER_WORD -@item BITS_PER_WORD +@defmac BITS_PER_WORD Number of bits in a word. If you do not define this macro, the default is @code{BITS_PER_UNIT * UNITS_PER_WORD}. +@end defmac -@findex MAX_BITS_PER_WORD -@item MAX_BITS_PER_WORD +@defmac MAX_BITS_PER_WORD Maximum number of bits in a word. If this is undefined, the default is @code{BITS_PER_WORD}. Otherwise, it is the constant value that is the largest value that @code{BITS_PER_WORD} can have at run-time. +@end defmac -@findex UNITS_PER_WORD -@item UNITS_PER_WORD +@defmac UNITS_PER_WORD Number of storage units in a word; normally 4. +@end defmac -@findex MIN_UNITS_PER_WORD -@item MIN_UNITS_PER_WORD +@defmac MIN_UNITS_PER_WORD Minimum number of units in a word. If this is undefined, the default is @code{UNITS_PER_WORD}. Otherwise, it is the constant value that is the smallest value that @code{UNITS_PER_WORD} can have at run-time. +@end defmac -@findex POINTER_SIZE -@item POINTER_SIZE +@defmac POINTER_SIZE Width of a pointer, in bits. You must specify a value no wider than the width of @code{Pmode}. If it is not equal to the width of @code{Pmode}, you must define @code{POINTERS_EXTEND_UNSIGNED}. If you do not specify a value the default is @code{BITS_PER_WORD}. +@end defmac -@findex POINTERS_EXTEND_UNSIGNED -@item POINTERS_EXTEND_UNSIGNED +@defmac POINTERS_EXTEND_UNSIGNED A C expression whose value is greater than zero if pointers that need to be extended from being @code{POINTER_SIZE} bits wide to @code{Pmode} are to be zero-extended and zero if they are to be sign-extended. If the value @@ -983,9 +1034,9 @@ extends a pointer from @code{POINTER_SIZE} to @code{Pmode}. You need not define this macro if the @code{POINTER_SIZE} is equal to the width of @code{Pmode}. +@end defmac -@findex PROMOTE_MODE -@item PROMOTE_MODE (@var{m}, @var{unsignedp}, @var{type}) +@defmac PROMOTE_MODE (@var{m}, @var{unsignedp}, @var{type}) A macro to update @var{m} and @var{unsignedp} when an object whose type is @var{type} and which has the specified mode and signedness is to be stored in a register. This macro is only called when @var{type} is a @@ -1006,52 +1057,53 @@ sign-extend the result to 64 bits. On such machines, set @var{unsignedp} according to which kind of extension is more efficient. Do not define this macro if it would never modify @var{m}. +@end defmac -@findex PROMOTE_FUNCTION_ARGS -@item PROMOTE_FUNCTION_ARGS -Define this macro if the promotion described by @code{PROMOTE_MODE} -should also be done for outgoing function arguments. +@deftypefn {Target Hook} bool TARGET_PROMOTE_FUNCTION_ARGS (tree @var{fntype}) +This target hook should return @code{true} if the promotion described by +@code{PROMOTE_MODE} should also be done for outgoing function arguments. +@end deftypefn -@findex PROMOTE_FUNCTION_RETURN -@item PROMOTE_FUNCTION_RETURN -Define this macro if the promotion described by @code{PROMOTE_MODE} -should also be done for the return value of functions. +@deftypefn {Target Hook} bool TARGET_PROMOTE_FUNCTION_RETURN (tree @var{fntype}) +This target hook should return @code{true} if the promotion described by +@code{PROMOTE_MODE} should also be done for the return value of +functions. -If this macro is defined, @code{FUNCTION_VALUE} must perform the same -promotions done by @code{PROMOTE_MODE}. +If this target hook returns @code{true}, @code{FUNCTION_VALUE} must +perform the same promotions done by @code{PROMOTE_MODE}. +@end deftypefn -@findex PROMOTE_FOR_CALL_ONLY -@item PROMOTE_FOR_CALL_ONLY +@defmac PROMOTE_FOR_CALL_ONLY Define this macro if the promotion described by @code{PROMOTE_MODE} should @emph{only} be performed for outgoing function arguments or -function return values, as specified by @code{PROMOTE_FUNCTION_ARGS} -and @code{PROMOTE_FUNCTION_RETURN}, respectively. +function return values, as specified by @code{TARGET_PROMOTE_FUNCTION_ARGS} +and @code{TARGET_PROMOTE_FUNCTION_RETURN}, respectively. +@end defmac -@findex PARM_BOUNDARY -@item PARM_BOUNDARY +@defmac PARM_BOUNDARY Normal alignment required for function parameters on the stack, in bits. All stack parameters receive at least this much alignment regardless of data type. On most machines, this is the same as the size of an integer. +@end defmac -@findex STACK_BOUNDARY -@item STACK_BOUNDARY +@defmac STACK_BOUNDARY Define this macro to the minimum alignment enforced by hardware for the stack pointer on this machine. The definition is a C expression for the desired alignment (measured in bits). This value is used as a default if @code{PREFERRED_STACK_BOUNDARY} is not defined. On most machines, this should be the same as @code{PARM_BOUNDARY}. +@end defmac -@findex PREFERRED_STACK_BOUNDARY -@item PREFERRED_STACK_BOUNDARY +@defmac PREFERRED_STACK_BOUNDARY Define this macro if you wish to preserve a certain alignment for the stack pointer, greater than what the hardware enforces. The definition is a C expression for the desired alignment (measured in bits). This macro must evaluate to a value equal to or larger than @code{STACK_BOUNDARY}. +@end defmac -@findex FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN -@item FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN +@defmac FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN A C expression that evaluates true if @code{PREFERRED_STACK_BOUNDARY} is not guaranteed by the runtime and we should emit code to align the stack at the beginning of @code{main}. @@ -1061,47 +1113,47 @@ If @code{PUSH_ROUNDING} is not defined, the stack will always be aligned to the specified boundary. If @code{PUSH_ROUNDING} is defined and specifies a less strict alignment than @code{PREFERRED_STACK_BOUNDARY}, the stack may be momentarily unaligned while pushing arguments. +@end defmac -@findex FUNCTION_BOUNDARY -@item FUNCTION_BOUNDARY +@defmac FUNCTION_BOUNDARY Alignment required for a function entry point, in bits. +@end defmac -@findex BIGGEST_ALIGNMENT -@item BIGGEST_ALIGNMENT +@defmac BIGGEST_ALIGNMENT Biggest alignment that any data type can require on this machine, in bits. +@end defmac -@findex MINIMUM_ATOMIC_ALIGNMENT -@item MINIMUM_ATOMIC_ALIGNMENT +@defmac MINIMUM_ATOMIC_ALIGNMENT If defined, the smallest alignment, in bits, that can be given to an object that can be referenced in one operation, without disturbing any nearby object. Normally, this is @code{BITS_PER_UNIT}, but may be larger on machines that don't have byte or half-word store operations. +@end defmac -@findex BIGGEST_FIELD_ALIGNMENT -@item BIGGEST_FIELD_ALIGNMENT +@defmac BIGGEST_FIELD_ALIGNMENT Biggest alignment that any structure or union field can require on this machine, in bits. If defined, this overrides @code{BIGGEST_ALIGNMENT} for structure and union fields only, unless the field alignment has been set by the @code{__attribute__ ((aligned (@var{n})))} construct. +@end defmac -@findex ADJUST_FIELD_ALIGN -@item ADJUST_FIELD_ALIGN (@var{field}, @var{computed}) +@defmac ADJUST_FIELD_ALIGN (@var{field}, @var{computed}) An expression for the alignment of a structure field @var{field} if the alignment computed in the usual way (including applying of @code{BIGGEST_ALIGNMENT} and @code{BIGGEST_FIELD_ALIGNMENT} to the alignment) is @var{computed}. It overrides alignment only if the field alignment has not been set by the @code{__attribute__ ((aligned (@var{n})))} construct. +@end defmac -@findex MAX_OFILE_ALIGNMENT -@item MAX_OFILE_ALIGNMENT +@defmac MAX_OFILE_ALIGNMENT Biggest alignment supported by the object file format of this machine. Use this macro to limit the alignment which can be specified using the @code{__attribute__ ((aligned (@var{n})))} construct. If not defined, the default value is @code{BIGGEST_ALIGNMENT}. +@end defmac -@findex DATA_ALIGNMENT -@item DATA_ALIGNMENT (@var{type}, @var{basic-align}) +@defmac DATA_ALIGNMENT (@var{type}, @var{basic-align}) If defined, a C expression to compute the alignment for a variable in the static store. @var{type} is the data type, and @var{basic-align} is the alignment that the object would ordinarily have. The value of this @@ -1114,9 +1166,9 @@ One use of this macro is to increase alignment of medium-size data to make it all fit in fewer cache lines. Another is to cause character arrays to be word-aligned so that @code{strcpy} calls that copy constants to character arrays can be done inline. +@end defmac -@findex CONSTANT_ALIGNMENT -@item CONSTANT_ALIGNMENT (@var{constant}, @var{basic-align}) +@defmac CONSTANT_ALIGNMENT (@var{constant}, @var{basic-align}) If defined, a C expression to compute the alignment given to a constant that is being placed in memory. @var{constant} is the constant and @var{basic-align} is the alignment that the object would ordinarily @@ -1128,9 +1180,9 @@ If this macro is not defined, then @var{basic-align} is used. The typical use of this macro is to increase alignment for string constants to be word aligned so that @code{strcpy} calls that copy constants can be done inline. +@end defmac -@findex LOCAL_ALIGNMENT -@item LOCAL_ALIGNMENT (@var{type}, @var{basic-align}) +@defmac LOCAL_ALIGNMENT (@var{type}, @var{basic-align}) If defined, a C expression to compute the alignment for a variable in the local store. @var{type} is the data type, and @var{basic-align} is the alignment that the object would ordinarily have. The value of this @@ -1140,45 +1192,46 @@ If this macro is not defined, then @var{basic-align} is used. One use of this macro is to increase alignment of medium-size data to make it all fit in fewer cache lines. +@end defmac -@findex EMPTY_FIELD_BOUNDARY -@item EMPTY_FIELD_BOUNDARY +@defmac EMPTY_FIELD_BOUNDARY Alignment in bits to be given to a structure bit-field that follows an empty field such as @code{int : 0;}. -Note that @code{PCC_BITFIELD_TYPE_MATTERS} also affects the alignment -that results from an empty field. +If @code{PCC_BITFIELD_TYPE_MATTERS} is true, it overrides this macro. +@end defmac -@findex STRUCTURE_SIZE_BOUNDARY -@item STRUCTURE_SIZE_BOUNDARY +@defmac STRUCTURE_SIZE_BOUNDARY Number of bits which any structure or union's size must be a multiple of. Each structure or union's size is rounded up to a multiple of this. If you do not define this macro, the default is the same as @code{BITS_PER_UNIT}. +@end defmac -@findex STRICT_ALIGNMENT -@item STRICT_ALIGNMENT +@defmac STRICT_ALIGNMENT Define this macro to be the value 1 if instructions will fail to work if given data not on the nominal alignment. If instructions will merely go slower in that case, define this macro as 0. +@end defmac -@findex PCC_BITFIELD_TYPE_MATTERS -@item PCC_BITFIELD_TYPE_MATTERS +@defmac PCC_BITFIELD_TYPE_MATTERS Define this if you wish to imitate the way many other C compilers handle alignment of bit-fields and the structures that contain them. -The behavior is that the type written for a bit-field (@code{int}, -@code{short}, or other integer type) imposes an alignment for the -entire structure, as if the structure really did contain an ordinary -field of that type. In addition, the bit-field is placed within the -structure so that it would fit within such a field, not crossing a -boundary for it. +The behavior is that the type written for a named bit-field (@code{int}, +@code{short}, or other integer type) imposes an alignment for the entire +structure, as if the structure really did contain an ordinary field of +that type. In addition, the bit-field is placed within the structure so +that it would fit within such a field, not crossing a boundary for it. + +Thus, on most machines, a named bit-field whose type is written as +@code{int} would not cross a four-byte boundary, and would force +four-byte alignment for the whole structure. (The alignment used may +not be four bytes; it is controlled by the other alignment parameters.) -Thus, on most machines, a bit-field whose type is written as @code{int} -would not cross a four-byte boundary, and would force four-byte -alignment for the whole structure. (The alignment used may not be four -bytes; it is controlled by the other alignment parameters.) +An unnamed bit-field will not affect the alignment of the containing +structure. If the macro is defined, its definition should be a C expression; a nonzero value for the expression enables this behavior. @@ -1200,7 +1253,7 @@ If your aim is to make GCC use the same conventions for laying out bit-fields as are used by another compiler, here is how to investigate what the other compiler does. Compile and run this program: -@example +@smallexample struct foo1 @{ char x; @@ -1223,18 +1276,18 @@ main () sizeof (struct foo2)); exit (0); @} -@end example +@end smallexample If this prints 2 and 5, then the compiler's behavior is what you would get from @code{PCC_BITFIELD_TYPE_MATTERS}. +@end defmac -@findex BITFIELD_NBYTES_LIMITED -@item BITFIELD_NBYTES_LIMITED +@defmac BITFIELD_NBYTES_LIMITED Like @code{PCC_BITFIELD_TYPE_MATTERS} except that its effect is limited to aligning a bit-field within the structure. +@end defmac -@findex MEMBER_TYPE_FORCES_BLK -@item MEMBER_TYPE_FORCES_BLK (@var{field}, @var{mode}) +@defmac MEMBER_TYPE_FORCES_BLK (@var{field}, @var{mode}) Return 1 if a structure or array containing @var{field} should be accessed using @code{BLKMODE}. @@ -1246,24 +1299,9 @@ retain the field's mode. Normally, this is not needed. See the file @file{c4x.h} for an example of how to use this macro to prevent a structure having a floating point field from being accessed in an integer mode. +@end defmac -@findex ROUND_TYPE_SIZE -@item ROUND_TYPE_SIZE (@var{type}, @var{computed}, @var{specified}) -Define this macro as an expression for the overall size of a type -(given by @var{type} as a tree node) when the size computed in the -usual way is @var{computed} and the alignment is @var{specified}. - -The default is to round @var{computed} up to a multiple of @var{specified}. - -@findex ROUND_TYPE_SIZE_UNIT -@item ROUND_TYPE_SIZE_UNIT (@var{type}, @var{computed}, @var{specified}) -Similar to @code{ROUND_TYPE_SIZE}, but sizes and alignments are -specified in units (bytes). If you define @code{ROUND_TYPE_SIZE}, -you must also define this macro and they must be defined consistently -with each other. - -@findex ROUND_TYPE_ALIGN -@item ROUND_TYPE_ALIGN (@var{type}, @var{computed}, @var{specified}) +@defmac ROUND_TYPE_ALIGN (@var{type}, @var{computed}, @var{specified}) Define this macro as an expression for the alignment of a type (given by @var{type} as a tree node) if the alignment computed in the usual way is @var{computed} and the alignment explicitly specified was @@ -1271,23 +1309,23 @@ way is @var{computed} and the alignment explicitly specified was The default is to use @var{specified} if it is larger; otherwise, use the smaller of @var{computed} and @code{BIGGEST_ALIGNMENT} +@end defmac -@findex MAX_FIXED_MODE_SIZE -@item MAX_FIXED_MODE_SIZE +@defmac MAX_FIXED_MODE_SIZE An integer expression for the size in bits of the largest integer machine mode that should actually be used. All integer machine modes of this size or smaller can be used for structures and unions with the appropriate sizes. If this macro is undefined, @code{GET_MODE_BITSIZE (DImode)} is assumed. +@end defmac -@findex VECTOR_MODE_SUPPORTED_P -@item VECTOR_MODE_SUPPORTED_P(@var{mode}) +@defmac VECTOR_MODE_SUPPORTED_P (@var{mode}) Define this macro to be nonzero if the port is prepared to handle insns involving vector mode @var{mode}. At the very least, it must have move patterns for this mode. +@end defmac -@findex STACK_SAVEAREA_MODE -@item STACK_SAVEAREA_MODE (@var{save_level}) +@defmac STACK_SAVEAREA_MODE (@var{save_level}) If defined, an expression of type @code{enum machine_mode} that specifies the mode of the save area operand of a @code{save_stack_@var{level}} named pattern (@pxref{Standard Names}). @@ -1299,9 +1337,9 @@ You need not define this macro if it always returns @code{Pmode}. You would most commonly define this macro if the @code{save_stack_@var{level}} patterns need to support both a 32- and a 64-bit mode. +@end defmac -@findex STACK_SIZE_MODE -@item STACK_SIZE_MODE +@defmac STACK_SIZE_MODE If defined, an expression of type @code{enum machine_mode} that specifies the mode of the size increment operand of an @code{allocate_stack} named pattern (@pxref{Standard Names}). @@ -1309,45 +1347,37 @@ specifies the mode of the size increment operand of an You need not define this macro if it always returns @code{word_mode}. You would most commonly define this macro if the @code{allocate_stack} pattern needs to support both a 32- and a 64-bit mode. +@end defmac -@findex TARGET_FLOAT_FORMAT -@item TARGET_FLOAT_FORMAT +@defmac TARGET_FLOAT_FORMAT A code distinguishing the floating point format of the target machine. -There are five defined values: +There are four defined values: -@table @code -@findex IEEE_FLOAT_FORMAT +@ftable @code @item IEEE_FLOAT_FORMAT This code indicates IEEE floating point. It is the default; there is no -need to define this macro when the format is IEEE@. +need to define @code{TARGET_FLOAT_FORMAT} when the format is IEEE@. -@findex VAX_FLOAT_FORMAT @item VAX_FLOAT_FORMAT This code indicates the ``F float'' (for @code{float}) and ``D float'' or ``G float'' formats (for @code{double}) used on the VAX and PDP-11@. -@findex IBM_FLOAT_FORMAT @item IBM_FLOAT_FORMAT This code indicates the format used on the IBM System/370. -@findex C4X_FLOAT_FORMAT @item C4X_FLOAT_FORMAT This code indicates the format used on the TMS320C3x/C4x. +@end ftable -@findex UNKNOWN_FLOAT_FORMAT -@item UNKNOWN_FLOAT_FORMAT -This code indicates any other format. -@end table - -If any other -formats are actually in use on supported machines, new codes should be -defined for them. +If your target uses a floating point format other than these, you must +define a new @var{name}_FLOAT_FORMAT code for it, and add support for +it to @file{real.c}. The ordering of the component words of floating point values stored in memory is controlled by @code{FLOAT_WORDS_BIG_ENDIAN}. +@end defmac -@findex MODE_HAS_NANS -@item MODE_HAS_NANS (@var{mode}) +@defmac MODE_HAS_NANS (@var{mode}) When defined, this macro should be true if @var{mode} has a NaN representation. The compiler assumes that NaNs are not equal to anything (including themselves) and that addition, subtraction, @@ -1356,16 +1386,16 @@ NaN@. By default, this macro is true if @var{mode} is a floating-point mode and the target floating-point format is IEEE@. +@end defmac -@findex MODE_HAS_INFINITIES -@item MODE_HAS_INFINITIES (@var{mode}) +@defmac MODE_HAS_INFINITIES (@var{mode}) This macro should be true if @var{mode} can represent infinity. At present, the compiler uses this macro to decide whether @samp{x - x} is always defined. By default, the macro is true when @var{mode} is a floating-point mode and the target format is IEEE@. +@end defmac -@findex MODE_HAS_SIGNED_ZEROS -@item MODE_HAS_SIGNED_ZEROS (@var{mode}) +@defmac MODE_HAS_SIGNED_ZEROS (@var{mode}) True if @var{mode} distinguishes between positive and negative zero. The rules are expected to follow the IEEE standard: @@ -1385,9 +1415,9 @@ of the operands is negative. The default definition is true if @var{mode} is a floating-point mode and the target format is IEEE@. +@end defmac -@findex MODE_HAS_SIGN_DEPENDENT_ROUNDING -@item MODE_HAS_SIGN_DEPENDENT_ROUNDING (@var{mode}) +@defmac MODE_HAS_SIGN_DEPENDENT_ROUNDING (@var{mode}) If defined, this macro should be true for @var{mode} if it has at least one rounding mode in which @samp{x} and @samp{-x} can be rounded to numbers of different magnitude. Two such modes are @@ -1395,9 +1425,9 @@ towards @minus{}infinity and towards +infinity. The default definition of this macro is true if @var{mode} is a floating-point mode and the target format is IEEE@. +@end defmac -@findex ROUND_TOWARDS_ZERO -@item ROUND_TOWARDS_ZERO +@defmac ROUND_TOWARDS_ZERO If defined, this macro should be true if the prevailing rounding mode is towards zero. A true value has the following effects: @@ -1421,9 +1451,9 @@ primary rounding mode is towards zero, library functions like parser should behave like the target's @code{strtod} where possible. Not defining this macro is equivalent to returning zero. +@end defmac -@findex LARGEST_EXPONENT_IS_NORMAL -@item LARGEST_EXPONENT_IS_NORMAL (@var{size}) +@defmac LARGEST_EXPONENT_IS_NORMAL (@var{size}) This macro should return true if floats with @var{size} bits do not have a NaN or infinity representation, but use the largest exponent for normal numbers instead. @@ -1434,7 +1464,15 @@ It also affects the way @file{libgcc.a} and @file{real.c} emulate floating-point arithmetic. The default definition of this macro returns false for all sizes. -@end table +@end defmac + +@deftypefn {Target Hook} bool TARGET_VECTOR_OPAQUE_P (tree @var{type}) +This target hook should return @code{true} a vector is opaque. That +is, if no cast is needed when copying a vector value of type +@var{type} into another vector lvalue of the same size. Vector opaque +types cannot be initialized. The default is that there are no such +types. +@end deftypefn @deftypefn {Target Hook} bool TARGET_MS_BITFIELD_LAYOUT_P (tree @var{record_type}) This target hook returns @code{true} if bit-fields in the given @@ -1472,116 +1510,115 @@ basic data types used in programs being compiled. Unlike the macros in the previous section, these apply to specific features of C and related languages, rather than to fundamental aspects of storage layout. -@table @code -@findex INT_TYPE_SIZE -@item INT_TYPE_SIZE +@defmac INT_TYPE_SIZE A C expression for the size in bits of the type @code{int} on the target machine. If you don't define this, the default is one word. +@end defmac -@findex SHORT_TYPE_SIZE -@item SHORT_TYPE_SIZE +@defmac SHORT_TYPE_SIZE A C expression for the size in bits of the type @code{short} on the target machine. If you don't define this, the default is half a word. (If this would be less than one storage unit, it is rounded up to one unit.) +@end defmac -@findex LONG_TYPE_SIZE -@item LONG_TYPE_SIZE +@defmac LONG_TYPE_SIZE A C expression for the size in bits of the type @code{long} on the target machine. If you don't define this, the default is one word. +@end defmac -@findex ADA_LONG_TYPE_SIZE -@item ADA_LONG_TYPE_SIZE +@defmac ADA_LONG_TYPE_SIZE On some machines, the size used for the Ada equivalent of the type @code{long} by a native Ada compiler differs from that used by C. In that situation, define this macro to be a C expression to be used for the size of that type. If you don't define this, the default is the value of @code{LONG_TYPE_SIZE}. +@end defmac -@findex MAX_LONG_TYPE_SIZE -@item MAX_LONG_TYPE_SIZE +@defmac MAX_LONG_TYPE_SIZE Maximum number for the size in bits of the type @code{long} on the target machine. If this is undefined, the default is @code{LONG_TYPE_SIZE}. Otherwise, it is the constant value that is the largest value that @code{LONG_TYPE_SIZE} can have at run-time. This is used in @code{cpp}. +@end defmac -@findex LONG_LONG_TYPE_SIZE -@item LONG_LONG_TYPE_SIZE +@defmac LONG_LONG_TYPE_SIZE A C expression for the size in bits of the type @code{long long} on the target machine. If you don't define this, the default is two words. If you want to support GNU Ada on your machine, the value of this macro must be at least 64. +@end defmac -@findex CHAR_TYPE_SIZE -@item CHAR_TYPE_SIZE +@defmac CHAR_TYPE_SIZE A C expression for the size in bits of the type @code{char} on the target machine. If you don't define this, the default is @code{BITS_PER_UNIT}. +@end defmac -@findex BOOL_TYPE_SIZE -@item BOOL_TYPE_SIZE +@defmac BOOL_TYPE_SIZE A C expression for the size in bits of the C++ type @code{bool} and C99 type @code{_Bool} on the target machine. If you don't define this, and you probably shouldn't, the default is @code{CHAR_TYPE_SIZE}. +@end defmac -@findex FLOAT_TYPE_SIZE -@item FLOAT_TYPE_SIZE +@defmac FLOAT_TYPE_SIZE A C expression for the size in bits of the type @code{float} on the target machine. If you don't define this, the default is one word. +@end defmac -@findex DOUBLE_TYPE_SIZE -@item DOUBLE_TYPE_SIZE +@defmac DOUBLE_TYPE_SIZE A C expression for the size in bits of the type @code{double} on the target machine. If you don't define this, the default is two words. +@end defmac -@findex LONG_DOUBLE_TYPE_SIZE -@item LONG_DOUBLE_TYPE_SIZE +@defmac LONG_DOUBLE_TYPE_SIZE A C expression for the size in bits of the type @code{long double} on the target machine. If you don't define this, the default is two words. +@end defmac -@findex MAX_LONG_DOUBLE_TYPE_SIZE +@defmac MAX_LONG_DOUBLE_TYPE_SIZE Maximum number for the size in bits of the type @code{long double} on the target machine. If this is undefined, the default is @code{LONG_DOUBLE_TYPE_SIZE}. Otherwise, it is the constant value that is the largest value that @code{LONG_DOUBLE_TYPE_SIZE} can have at run-time. This is used in @code{cpp}. +@end defmac -@findex TARGET_FLT_EVAL_METHOD -@item TARGET_FLT_EVAL_METHOD +@defmac TARGET_FLT_EVAL_METHOD A C expression for the value for @code{FLT_EVAL_METHOD} in @file{float.h}, assuming, if applicable, that the floating-point control word is in its default state. If you do not define this macro the value of @code{FLT_EVAL_METHOD} will be zero. +@end defmac -@findex WIDEST_HARDWARE_FP_SIZE -@item WIDEST_HARDWARE_FP_SIZE +@defmac WIDEST_HARDWARE_FP_SIZE A C expression for the size in bits of the widest floating-point format supported by the hardware. If you define this macro, you must specify a value less than or equal to the value of @code{LONG_DOUBLE_TYPE_SIZE}. If you do not define this macro, the value of @code{LONG_DOUBLE_TYPE_SIZE} is the default. +@end defmac -@findex DEFAULT_SIGNED_CHAR -@item DEFAULT_SIGNED_CHAR +@defmac DEFAULT_SIGNED_CHAR An expression whose value is 1 or 0, according to whether the type @code{char} should be signed or unsigned by default. The user can always override this default with the options @option{-fsigned-char} and @option{-funsigned-char}. +@end defmac -@findex DEFAULT_SHORT_ENUMS -@item DEFAULT_SHORT_ENUMS +@defmac DEFAULT_SHORT_ENUMS A C expression to determine whether to give an @code{enum} type only as many bytes as it takes to represent the range of possible values of that type. A nonzero value means to do that; a zero value means all @code{enum} types should be allocated like @code{int}. If you don't define the macro, the default is 0. +@end defmac -@findex SIZE_TYPE -@item SIZE_TYPE +@defmac SIZE_TYPE A C expression for a string describing the name of the data type to use for size values. The typedef name @code{size_t} is defined using the contents of the string. @@ -1596,49 +1633,49 @@ crash on startup. If you don't define this macro, the default is @code{"long unsigned int"}. +@end defmac -@findex PTRDIFF_TYPE -@item PTRDIFF_TYPE +@defmac PTRDIFF_TYPE A C expression for a string describing the name of the data type to use for the result of subtracting two pointers. The typedef name @code{ptrdiff_t} is defined using the contents of the string. See @code{SIZE_TYPE} above for more information. If you don't define this macro, the default is @code{"long int"}. +@end defmac -@findex WCHAR_TYPE -@item WCHAR_TYPE +@defmac WCHAR_TYPE A C expression for a string describing the name of the data type to use for wide characters. The typedef name @code{wchar_t} is defined using the contents of the string. See @code{SIZE_TYPE} above for more information. If you don't define this macro, the default is @code{"int"}. +@end defmac -@findex WCHAR_TYPE_SIZE -@item WCHAR_TYPE_SIZE +@defmac WCHAR_TYPE_SIZE A C expression for the size in bits of the data type for wide characters. This is used in @code{cpp}, which cannot make use of @code{WCHAR_TYPE}. +@end defmac -@findex MAX_WCHAR_TYPE_SIZE -@item MAX_WCHAR_TYPE_SIZE +@defmac MAX_WCHAR_TYPE_SIZE Maximum number for the size in bits of the data type for wide characters. If this is undefined, the default is @code{WCHAR_TYPE_SIZE}. Otherwise, it is the constant value that is the largest value that @code{WCHAR_TYPE_SIZE} can have at run-time. This is used in @code{cpp}. +@end defmac -@findex GCOV_TYPE_SIZE -@item GCOV_TYPE_SIZE +@defmac GCOV_TYPE_SIZE A C expression for the size in bits of the type used for gcov counters on the target machine. If you don't define this, the default is one @code{LONG_TYPE_SIZE} in case it is greater or equal to 64-bit and @code{LONG_LONG_TYPE_SIZE} otherwise. You may want to re-define the type to ensure atomicity for counters in multithreaded programs. +@end defmac -@findex WINT_TYPE -@item WINT_TYPE +@defmac WINT_TYPE A C expression for a string describing the name of the data type to use for wide characters passed to @code{printf} and returned from @code{getwc}. The typedef name @code{wint_t} is defined using the @@ -1646,9 +1683,9 @@ contents of the string. See @code{SIZE_TYPE} above for more information. If you don't define this macro, the default is @code{"unsigned int"}. +@end defmac -@findex INTMAX_TYPE -@item INTMAX_TYPE +@defmac INTMAX_TYPE A C expression for a string describing the name of the data type that can represent any value of any standard or extended signed integer type. The typedef name @code{intmax_t} is defined using the contents of the @@ -1657,9 +1694,9 @@ string. See @code{SIZE_TYPE} above for more information. If you don't define this macro, the default is the first of @code{"int"}, @code{"long int"}, or @code{"long long int"} that has as much precision as @code{long long int}. +@end defmac -@findex UINTMAX_TYPE -@item UINTMAX_TYPE +@defmac UINTMAX_TYPE A C expression for a string describing the name of the data type that can represent any value of any standard or extended unsigned integer type. The typedef name @code{uintmax_t} is defined using the contents @@ -1669,13 +1706,13 @@ If you don't define this macro, the default is the first of @code{"unsigned int"}, @code{"long unsigned int"}, or @code{"long long unsigned int"} that has as much precision as @code{long long unsigned int}. +@end defmac -@findex TARGET_PTRMEMFUNC_VBIT_LOCATION -@item TARGET_PTRMEMFUNC_VBIT_LOCATION +@defmac TARGET_PTRMEMFUNC_VBIT_LOCATION The C++ compiler represents a pointer-to-member-function with a struct that looks like: -@example +@smallexample struct @{ union @{ void (*fn)(); @@ -1683,7 +1720,7 @@ that looks like: @}; ptrdiff_t delta; @}; -@end example +@end smallexample @noindent The C++ compiler must use one bit to indicate whether the function that @@ -1708,9 +1745,9 @@ In general, you should not have to define this macro. On architectures in which function addresses are always even, according to @code{FUNCTION_BOUNDARY}, GCC will automatically define this macro to @code{ptrmemfunc_vbit_in_pfn}. +@end defmac -@findex TARGET_VTABLE_USES_DESCRIPTORS -@item TARGET_VTABLE_USES_DESCRIPTORS +@defmac TARGET_VTABLE_USES_DESCRIPTORS Normally, the C++ compiler uses function pointers in vtables. This macro allows the target to change to use ``function descriptors'' instead. Function descriptors are found on targets for whom a @@ -1720,21 +1757,21 @@ pointer to which the function's data is relative. If vtables are used, the value of this macro should be the number of words that the function descriptor occupies. +@end defmac -@findex TARGET_VTABLE_ENTRY_ALIGN -@item TARGET_VTABLE_ENTRY_ALIGN +@defmac TARGET_VTABLE_ENTRY_ALIGN By default, the vtable entries are void pointers, the so the alignment is the same as pointer alignment. The value of this macro specifies the alignment of the vtable entry in bits. It should be defined only when special alignment is necessary. */ +@end defmac -@findex TARGET_VTABLE_DATA_ENTRY_DISTANCE -@item TARGET_VTABLE_DATA_ENTRY_DISTANCE +@defmac TARGET_VTABLE_DATA_ENTRY_DISTANCE There are a few non-descriptor entries in the vtable at offsets below zero. If these entries must be padded (say, to preserve the alignment specified by @code{TARGET_VTABLE_ENTRY_ALIGN}), set this to the number of words in each data entry. -@end table +@end defmac @node Escape Sequences @section Target Character Escape Sequences @@ -1742,38 +1779,30 @@ of words in each data entry. By default, GCC assumes that the C character escape sequences take on their ASCII values for the target. If this is not correct, you must -explicitly define all of the macros below. +explicitly define all of the macros below. All of them must evaluate +to constants; they are used in @code{case} statements. -@table @code @findex TARGET_BELL -@item TARGET_BELL -A C constant expression for the integer value for escape sequence -@samp{\a}. - +@findex TARGET_CR @findex TARGET_ESC -@item TARGET_ESC -A C constant expression for the integer value of the target escape -character. As an extension, GCC evaluates the escape sequences -@samp{\e} and @samp{\E} to this. - -@findex TARGET_TAB -@findex TARGET_BS +@findex TARGET_FF @findex TARGET_NEWLINE -@item TARGET_BS -@itemx TARGET_TAB -@itemx TARGET_NEWLINE -C constant expressions for the integer values for escape sequences -@samp{\b}, @samp{\t} and @samp{\n}. - +@findex TARGET_TAB @findex TARGET_VT -@findex TARGET_FF -@findex TARGET_CR -@item TARGET_VT -@itemx TARGET_FF -@itemx TARGET_CR -C constant expressions for the integer values for escape sequences -@samp{\v}, @samp{\f} and @samp{\r}. -@end table +@multitable {@code{TARGET_NEWLINE}} {Escape} {ASCII character} +@item Macro @tab Escape @tab ASCII character +@item @code{TARGET_BELL} @tab @kbd{\a} @tab @code{07}, @code{BEL} +@item @code{TARGET_CR} @tab @kbd{\r} @tab @code{0D}, @code{CR} +@item @code{TARGET_ESC} @tab @kbd{\e}, @kbd{\E} @tab @code{1B}, @code{ESC} +@item @code{TARGET_FF} @tab @kbd{\f} @tab @code{0C}, @code{FF} +@item @code{TARGET_NEWLINE} @tab @kbd{\n} @tab @code{0A}, @code{LF} +@item @code{TARGET_TAB} @tab @kbd{\t} @tab @code{09}, @code{HT} +@item @code{TARGET_VT} @tab @kbd{\v} @tab @code{0B}, @code{VT} +@end multitable + +@noindent +Note that the @kbd{\e} and @kbd{\E} escapes are GNU extensions, not +part of the C standard. @node Registers @section Register Usage @@ -1802,16 +1831,14 @@ For returning values in registers, see @ref{Scalar Return}. @c prevent bad page break with this line Registers have various characteristics. -@table @code -@findex FIRST_PSEUDO_REGISTER -@item FIRST_PSEUDO_REGISTER +@defmac FIRST_PSEUDO_REGISTER Number of hardware registers known to the compiler. They receive numbers 0 through @code{FIRST_PSEUDO_REGISTER-1}; thus, the first pseudo register's number really is assigned the number @code{FIRST_PSEUDO_REGISTER}. +@end defmac -@item FIXED_REGISTERS -@findex FIXED_REGISTERS +@defmac FIXED_REGISTERS @cindex fixed register An initializer that says which registers are used for fixed purposes all throughout the compiled code and are therefore not available for @@ -1830,9 +1857,9 @@ the following one, may be overridden at run time either automatically, by the actions of the macro @code{CONDITIONAL_REGISTER_USAGE}, or by the user with the command options @option{-ffixed-@var{reg}}, @option{-fcall-used-@var{reg}} and @option{-fcall-saved-@var{reg}}. +@end defmac -@findex CALL_USED_REGISTERS -@item CALL_USED_REGISTERS +@defmac CALL_USED_REGISTERS @cindex call-used register @cindex call-clobbered register @cindex call-saved register @@ -1845,9 +1872,9 @@ function calls. If a register has 0 in @code{CALL_USED_REGISTERS}, the compiler automatically saves it on function entry and restores it on function exit, if the register is used within the function. +@end defmac -@findex CALL_REALLY_USED_REGISTERS -@item CALL_REALLY_USED_REGISTERS +@defmac CALL_REALLY_USED_REGISTERS @cindex call-used register @cindex call-clobbered register @cindex call-saved register @@ -1856,9 +1883,9 @@ that the entire set of @code{FIXED_REGISTERS} be included. (@code{CALL_USED_REGISTERS} must be a superset of @code{FIXED_REGISTERS}). This macro is optional. If not specified, it defaults to the value of @code{CALL_USED_REGISTERS}. +@end defmac -@findex HARD_REGNO_CALL_PART_CLOBBERED -@item HARD_REGNO_CALL_PART_CLOBBERED (@var{regno}, @var{mode}) +@defmac HARD_REGNO_CALL_PART_CLOBBERED (@var{regno}, @var{mode}) @cindex call-used register @cindex call-clobbered register @cindex call-saved register @@ -1867,11 +1894,14 @@ value of mode @var{mode} in hard register number @var{regno} across a call without some part of it being clobbered. For most machines this macro need not be defined. It is only required for machines that do not preserve the entire contents of a register across a call. +@end defmac -@findex CONDITIONAL_REGISTER_USAGE @findex fixed_regs @findex call_used_regs -@item CONDITIONAL_REGISTER_USAGE +@findex global_regs +@findex reg_names +@findex reg_class_contents +@defmac CONDITIONAL_REGISTER_USAGE Zero or more C statements that may conditionally modify five variables @code{fixed_regs}, @code{call_used_regs}, @code{global_regs}, @code{reg_names}, and @code{reg_class_contents}, to take into account @@ -1895,53 +1925,52 @@ If the usage of an entire class of registers depends on the target flags, you may indicate this to GCC by using this macro to modify @code{fixed_regs} and @code{call_used_regs} to 1 for each of the registers in the classes which should not be used by GCC@. Also define -the macro @code{REG_CLASS_FROM_LETTER} to return @code{NO_REGS} if it +the macro @code{REG_CLASS_FROM_LETTER} / @code{REG_CLASS_FROM_CONSTRAINT} +to return @code{NO_REGS} if it is called with a letter for a class that shouldn't be used. (However, if this class is not included in @code{GENERAL_REGS} and all of the insn patterns whose constraints permit this class are controlled by target switches, then GCC will automatically avoid using these registers when the target switches are opposed to them.) +@end defmac -@findex NON_SAVING_SETJMP -@item NON_SAVING_SETJMP +@defmac NON_SAVING_SETJMP If this macro is defined and has a nonzero value, it means that @code{setjmp} and related functions fail to save the registers, or that @code{longjmp} fails to restore them. To compensate, the compiler avoids putting variables in registers in functions that use @code{setjmp}. +@end defmac -@findex INCOMING_REGNO -@item INCOMING_REGNO (@var{out}) +@defmac INCOMING_REGNO (@var{out}) Define this macro if the target machine has register windows. This C expression returns the register number as seen by the called function corresponding to the register number @var{out} as seen by the calling function. Return @var{out} if register number @var{out} is not an outbound register. +@end defmac -@findex OUTGOING_REGNO -@item OUTGOING_REGNO (@var{in}) +@defmac OUTGOING_REGNO (@var{in}) Define this macro if the target machine has register windows. This C expression returns the register number as seen by the calling function corresponding to the register number @var{in} as seen by the called function. Return @var{in} if register number @var{in} is not an inbound register. +@end defmac -@findex LOCAL_REGNO -@item LOCAL_REGNO (@var{regno}) +@defmac LOCAL_REGNO (@var{regno}) Define this macro if the target machine has register windows. This C expression returns true if the register is call-saved but is in the register window. Unlike most call-saved registers, such registers need not be explicitly restored on function exit or during non-local gotos. +@end defmac -@ignore -@findex PC_REGNUM -@item PC_REGNUM +@defmac PC_REGNUM If the program counter has a register number, define this as that register number. Otherwise, do not define it. -@end ignore -@end table +@end defmac @node Allocation Order @subsection Order of Allocation of Registers @@ -1951,9 +1980,7 @@ register number. Otherwise, do not define it. @c prevent bad page break with this line Registers are allocated in order. -@table @code -@findex REG_ALLOC_ORDER -@item REG_ALLOC_ORDER +@defmac REG_ALLOC_ORDER If defined, an initializer for a vector of integers, containing the numbers of hard registers in the order in which GCC should prefer to use them (from most preferred to least). @@ -1966,9 +1993,9 @@ registers must always be saved and the save-multiple-registers instruction supports only sequences of consecutive registers. On such machines, define @code{REG_ALLOC_ORDER} to be an initializer that lists the highest numbered allocable register first. +@end defmac -@findex ORDER_REGS_FOR_LOCAL_ALLOC -@item ORDER_REGS_FOR_LOCAL_ALLOC +@defmac ORDER_REGS_FOR_LOCAL_ALLOC A C statement (sans semicolon) to choose the order in which to allocate hard registers for pseudo-registers local to a basic block. @@ -1980,7 +2007,7 @@ The macro body should not assume anything about the contents of @code{reg_alloc_order} before execution of the macro. On most machines, it is not necessary to define this macro. -@end table +@end defmac @node Values in Registers @subsection How Values Fit in Registers @@ -1989,9 +2016,7 @@ This section discusses the macros that describe which kinds of values (specifically, which machine modes) each register can hold, and how many consecutive registers are needed for a given mode. -@table @code -@findex HARD_REGNO_NREGS -@item HARD_REGNO_NREGS (@var{regno}, @var{mode}) +@defmac HARD_REGNO_NREGS (@var{regno}, @var{mode}) A C expression for the number of consecutive hard registers, starting at register number @var{regno}, required to hold a value of mode @var{mode}. @@ -2004,9 +2029,18 @@ definition of this macro is ((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1) \ / UNITS_PER_WORD) @end smallexample +@end defmac + +@defmac REGMODE_NATURAL_SIZE (@var{mode}) +Define this macro if the natural size of registers that hold values +of mode @var{mode} is not the word size. It is a C expression that +should give the natural size in bytes for the specified mode. It is +used by the register allocator to try to optimize its results. This +happens for example on SPARC 64-bit where the natural size of +floating-point registers is still 32-bit. +@end defmac -@findex HARD_REGNO_MODE_OK -@item HARD_REGNO_MODE_OK (@var{regno}, @var{mode}) +@defmac HARD_REGNO_MODE_OK (@var{regno}, @var{mode}) A C expression that is nonzero if it is permissible to store a value of mode @var{mode} in hard register number @var{regno} (or in several registers starting with that one). For a machine where all registers @@ -2065,9 +2099,9 @@ so that it is better to store a value in a stack frame than in such a register if floating point arithmetic is not being done. As long as the floating registers are not in class @code{GENERAL_REGS}, they will not be used unless some pattern's constraint asks for one. +@end defmac -@findex MODES_TIEABLE_P -@item MODES_TIEABLE_P (@var{mode1}, @var{mode2}) +@defmac MODES_TIEABLE_P (@var{mode1}, @var{mode2}) A C expression that is nonzero if a value of mode @var{mode1} is accessible in mode @var{mode2} without copying. @@ -2081,13 +2115,13 @@ accessibility of the value in a narrower mode. You should define this macro to return nonzero in as many cases as possible since doing so will allow GCC to perform better register allocation. +@end defmac -@findex AVOID_CCMODE_COPIES -@item AVOID_CCMODE_COPIES +@defmac AVOID_CCMODE_COPIES Define this macro if the compiler should avoid copies to/from @code{CCmode} registers. You should only define this macro if support for copying to/from @code{CCmode} is incomplete. -@end table +@end defmac @node Leaf Functions @subsection Handling Leaf Functions @@ -2112,9 +2146,7 @@ suitable for leaf function treatment. So it needs to renumber the registers in order to output a leaf function. The following macros accomplish this. -@table @code -@findex LEAF_REGISTERS -@item LEAF_REGISTERS +@defmac LEAF_REGISTERS Name of a char vector, indexed by hard register number, which contains 1 for a register that is allowable in a candidate for leaf function treatment. @@ -2127,9 +2159,9 @@ in this vector. Define this macro only if the target machine offers a way to optimize the treatment of leaf functions. +@end defmac -@findex LEAF_REG_REMAP -@item LEAF_REG_REMAP (@var{regno}) +@defmac LEAF_REG_REMAP (@var{regno}) A C expression whose value is the register number to which @var{regno} should be renumbered, when a function is treated as a leaf function. @@ -2140,7 +2172,7 @@ will cause the compiler to abort. Define this macro only if the target machine offers a way to optimize the treatment of leaf functions, and registers need to be renumbered to do this. -@end table +@end defmac @findex current_function_is_leaf @findex current_function_uses_only_leaf_regs @@ -2161,28 +2193,31 @@ only useful if @code{LEAF_REGISTERS} is defined. @subsection Registers That Form a Stack There are special features to handle computers where some of the -``registers'' form a stack, as in the 80387 coprocessor for the 80386. -Stack registers are normally written by pushing onto the stack, and are -numbered relative to the top of the stack. +``registers'' form a stack. Stack registers are normally written by +pushing onto the stack, and are numbered relative to the top of the +stack. Currently, GCC can only handle one group of stack-like registers, and -they must be consecutively numbered. - -@table @code -@findex STACK_REGS -@item STACK_REGS +they must be consecutively numbered. Furthermore, the existing +support for stack-like registers is specific to the 80387 floating +point coprocessor. If you have a new architecture that uses +stack-like registers, you will need to do substantial work on +@file{reg-stack.c} and write your machine description to cooperate +with it, as well as defining these macros. + +@defmac STACK_REGS Define this if the machine has any stack-like registers. +@end defmac -@findex FIRST_STACK_REG -@item FIRST_STACK_REG +@defmac FIRST_STACK_REG The number of the first stack-like register. This one is the top of the stack. +@end defmac -@findex LAST_STACK_REG -@item LAST_STACK_REG +@defmac LAST_STACK_REG The number of the last stack-like register. This one is the bottom of the stack. -@end table +@end defmac @node Register Classes @section Register Classes @@ -2247,34 +2282,32 @@ instruction must have a subclass consisting of registers from which single-byte values can be loaded or stored. This is so that @code{PREFERRED_RELOAD_CLASS} can always have a possible value to return. -@table @code -@findex enum reg_class -@item enum reg_class -An enumeral type that must be defined with all the register class names -as enumeral values. @code{NO_REGS} must be first. @code{ALL_REGS} -must be the last register class, followed by one more enumeral value, +@deftp {Data type} {enum reg_class} +An enumerated type that must be defined with all the register class names +as enumerated values. @code{NO_REGS} must be first. @code{ALL_REGS} +must be the last register class, followed by one more enumerated value, @code{LIM_REG_CLASSES}, which is not a register class but rather tells how many classes there are. Each register class has a number, which is the value of casting the class name to type @code{int}. The number serves as an index in many of the tables described below. +@end deftp -@findex N_REG_CLASSES -@item N_REG_CLASSES +@defmac N_REG_CLASSES The number of distinct register classes, defined as follows: -@example +@smallexample #define N_REG_CLASSES (int) LIM_REG_CLASSES -@end example +@end smallexample +@end defmac -@findex REG_CLASS_NAMES -@item REG_CLASS_NAMES +@defmac REG_CLASS_NAMES An initializer containing the names of the register classes as C string constants. These names are used in writing some of the debugging dumps. +@end defmac -@findex REG_CLASS_CONTENTS -@item REG_CLASS_CONTENTS +@defmac REG_CLASS_CONTENTS An initializer containing the contents of the register classes, as integers which are bit masks. The @var{n}th integer specifies the contents of class @var{n}. The way the integer @var{mask} is interpreted is that @@ -2287,61 +2320,82 @@ for the type @code{HARD_REG_SET} which is defined in @file{hard-reg-set.h}. In this situation, the first integer in each sub-initializer corresponds to registers 0 through 31, the second integer to registers 32 through 63, and so on. +@end defmac -@findex REGNO_REG_CLASS -@item REGNO_REG_CLASS (@var{regno}) +@defmac REGNO_REG_CLASS (@var{regno}) A C expression whose value is a register class containing hard register @var{regno}. In general there is more than one such class; choose a class which is @dfn{minimal}, meaning that no smaller class also contains the register. +@end defmac -@findex BASE_REG_CLASS -@item BASE_REG_CLASS +@defmac BASE_REG_CLASS A macro whose definition is the name of the class to which a valid base register must belong. A base register is one used in an address which is the register value plus a displacement. +@end defmac -@findex MODE_BASE_REG_CLASS -@item MODE_BASE_REG_CLASS (@var{mode}) +@defmac MODE_BASE_REG_CLASS (@var{mode}) This is a variation of the @code{BASE_REG_CLASS} macro which allows the selection of a base register in a mode dependent manner. If @var{mode} is VOIDmode then it should return the same value as @code{BASE_REG_CLASS}. +@end defmac -@findex INDEX_REG_CLASS -@item INDEX_REG_CLASS +@defmac INDEX_REG_CLASS A macro whose definition is the name of the class to which a valid index register must belong. An index register is one used in an address where its value is either multiplied by a scale factor or added to another register (as well as added to a displacement). +@end defmac + +@defmac CONSTRAINT_LEN (@var{char}, @var{str}) +For the constraint at the start of @var{str}, which starts with the letter +@var{c}, return the length. This allows you to have register class / +constant / extra constraints that are longer than a single letter; +you don't need to define this macro if you can do with single-letter +constraints only. The definition of this macro should use +DEFAULT_CONSTRAINT_LEN for all the characters that you don't want +to handle specially. +There are some sanity checks in genoutput.c that check the constraint lengths +for the md file, so you can also use this macro to help you while you are +transitioning from a byzantine single-letter-constraint scheme: when you +return a negative length for a constraint you want to re-use, genoutput +will complain about every instance where it is used in the md file. +@end defmac -@findex REG_CLASS_FROM_LETTER -@item REG_CLASS_FROM_LETTER (@var{char}) +@defmac REG_CLASS_FROM_LETTER (@var{char}) A C expression which defines the machine-dependent operand constraint letters for register classes. If @var{char} is such a letter, the value should be the register class corresponding to it. Otherwise, the value should be @code{NO_REGS}. The register letter @samp{r}, corresponding to class @code{GENERAL_REGS}, will not be passed to this macro; you do not need to handle it. +@end defmac + +@defmac REG_CLASS_FROM_CONSTRAINT (@var{char}, @var{str}) +Like @code{REG_CLASS_FROM_LETTER}, but you also get the constraint string +passed in @var{str}, so that you can use suffixes to distinguish between +different variants. +@end defmac -@findex REGNO_OK_FOR_BASE_P -@item REGNO_OK_FOR_BASE_P (@var{num}) +@defmac REGNO_OK_FOR_BASE_P (@var{num}) A C expression which is nonzero if register number @var{num} is suitable for use as a base register in operand addresses. It may be either a suitable hard register or a pseudo register that has been allocated such a hard register. +@end defmac -@findex REGNO_MODE_OK_FOR_BASE_P -@item REGNO_MODE_OK_FOR_BASE_P (@var{num}, @var{mode}) +@defmac REGNO_MODE_OK_FOR_BASE_P (@var{num}, @var{mode}) A C expression that is just like @code{REGNO_OK_FOR_BASE_P}, except that that expression may examine the mode of the memory reference in @var{mode}. You should define this macro if the mode of the memory reference affects whether a register may be used as a base register. If you define this macro, the compiler will use it instead of @code{REGNO_OK_FOR_BASE_P}. +@end defmac -@findex REGNO_OK_FOR_INDEX_P -@item REGNO_OK_FOR_INDEX_P (@var{num}) +@defmac REGNO_OK_FOR_INDEX_P (@var{num}) A C expression which is nonzero if register number @var{num} is suitable for use as an index register in operand addresses. It may be either a suitable hard register or a pseudo register that has been @@ -2355,18 +2409,18 @@ labeling is used must fit the machine's constraints of which registers may serve in each capacity. The compiler will try both labelings, looking for one that is valid, and will reload one or both registers only if neither labeling works. +@end defmac -@findex PREFERRED_RELOAD_CLASS -@item PREFERRED_RELOAD_CLASS (@var{x}, @var{class}) +@defmac PREFERRED_RELOAD_CLASS (@var{x}, @var{class}) A C expression that places additional restrictions on the register class to use when it is necessary to copy value @var{x} into a register in class @var{class}. The value is a register class; perhaps @var{class}, or perhaps another, smaller class. On many machines, the following definition is safe: -@example +@smallexample #define PREFERRED_RELOAD_CLASS(X,CLASS) CLASS -@end example +@end smallexample Sometimes returning a more restrictive class makes better code. For example, on the 68000, when @var{x} is an integer constant that is in range @@ -2374,19 +2428,26 @@ for a @samp{moveq} instruction, the value of this macro is always @code{DATA_REGS} as long as @var{class} includes the data registers. Requiring a data register guarantees that a @samp{moveq} will be used. -If @var{x} is a @code{const_double}, by returning @code{NO_REGS} -you can force @var{x} into a memory constant. This is useful on -certain machines where immediate floating values cannot be loaded into -certain kinds of registers. +One case where @code{PREFERRED_RELOAD_CLASS} must not return +@var{class} is if @var{x} is a legitimate constant which cannot be +loaded into some register class. By returning @code{NO_REGS} you can +force @var{x} into a memory location. For example, rs6000 can load +immediate values into general-purpose registers, but does not have an +instruction for loading an immediate value into a floating-point +register, so @code{PREFERRED_RELOAD_CLASS} returns @code{NO_REGS} when +@var{x} is a floating-point constant. If the constant can't be loaded +into any kind of register, code generation will be better if +@code{LEGITIMATE_CONSTANT_P} makes the constant illegitimate instead +of using @code{PREFERRED_RELOAD_CLASS}. +@end defmac -@findex PREFERRED_OUTPUT_RELOAD_CLASS -@item PREFERRED_OUTPUT_RELOAD_CLASS (@var{x}, @var{class}) +@defmac PREFERRED_OUTPUT_RELOAD_CLASS (@var{x}, @var{class}) Like @code{PREFERRED_RELOAD_CLASS}, but for output reloads instead of input reloads. If you don't define this macro, the default is to use @var{class}, unchanged. +@end defmac -@findex LIMIT_RELOAD_CLASS -@item LIMIT_RELOAD_CLASS (@var{mode}, @var{class}) +@defmac LIMIT_RELOAD_CLASS (@var{mode}, @var{class}) A C expression that places additional restrictions on the register class to use when it is necessary to be able to hold a value of mode @var{mode} in a reload register for which class @var{class} would @@ -2400,13 +2461,11 @@ smaller class. Don't define this macro unless the target machine has limitations which require the macro to do something nontrivial. +@end defmac -@findex SECONDARY_RELOAD_CLASS -@findex SECONDARY_INPUT_RELOAD_CLASS -@findex SECONDARY_OUTPUT_RELOAD_CLASS -@item SECONDARY_RELOAD_CLASS (@var{class}, @var{mode}, @var{x}) -@itemx SECONDARY_INPUT_RELOAD_CLASS (@var{class}, @var{mode}, @var{x}) -@itemx SECONDARY_OUTPUT_RELOAD_CLASS (@var{class}, @var{mode}, @var{x}) +@defmac SECONDARY_RELOAD_CLASS (@var{class}, @var{mode}, @var{x}) +@defmacx SECONDARY_INPUT_RELOAD_CLASS (@var{class}, @var{mode}, @var{x}) +@defmacx SECONDARY_OUTPUT_RELOAD_CLASS (@var{class}, @var{mode}, @var{x}) Many machines have some registers that cannot be copied directly to or from memory or even from other types of registers. An example is the @samp{MQ} register, which on most machines, can only be copied to or @@ -2465,9 +2524,9 @@ would not be helpful. Instead, a stack location must be used to perform the copy and the @code{mov@var{m}} pattern should use memory as an intermediate storage. This case often occurs between floating-point and general registers. +@end defmac -@findex SECONDARY_MEMORY_NEEDED -@item SECONDARY_MEMORY_NEEDED (@var{class1}, @var{class2}, @var{m}) +@defmac SECONDARY_MEMORY_NEEDED (@var{class1}, @var{class2}, @var{m}) Certain machines have the property that some registers cannot be copied to some other registers without using memory. Define this macro on those machines to be a C expression that is nonzero if objects of mode @@ -2476,9 +2535,9 @@ class @var{class2} by storing a register of @var{class1} into memory and loading that memory location into a register of @var{class2}. Do not define this macro if its value would always be zero. +@end defmac -@findex SECONDARY_MEMORY_NEEDED_RTX -@item SECONDARY_MEMORY_NEEDED_RTX (@var{mode}) +@defmac SECONDARY_MEMORY_NEEDED_RTX (@var{mode}) Normally when @code{SECONDARY_MEMORY_NEEDED} is defined, the compiler allocates a stack slot for a memory location needed for register copies. If this macro is defined, the compiler instead uses the memory location @@ -2486,9 +2545,9 @@ defined by this macro. Do not define this macro if you do not define @code{SECONDARY_MEMORY_NEEDED}. +@end defmac -@findex SECONDARY_MEMORY_NEEDED_MODE -@item SECONDARY_MEMORY_NEEDED_MODE (@var{mode}) +@defmac SECONDARY_MEMORY_NEEDED_MODE (@var{mode}) When the compiler needs a secondary memory location to copy between two registers of mode @var{mode}, it normally allocates sufficient memory to hold a quantity of @code{BITS_PER_WORD} bits and performs the store and @@ -2510,9 +2569,9 @@ details. Do not define this macro if you do not define @code{SECONDARY_MEMORY_NEEDED} or if widening @var{mode} to a mode that is @code{BITS_PER_WORD} bits wide is correct for your machine. +@end defmac -@findex SMALL_REGISTER_CLASSES -@item SMALL_REGISTER_CLASSES +@defmac SMALL_REGISTER_CLASSES On some machines, it is risky to let hard registers live across arbitrary insns. Typically, these machines have instructions that require values to be in specific registers (like an accumulator), and reload will fail @@ -2529,9 +2588,9 @@ that can be performed in some cases. If you do not define this macro with a nonzero value when it is required, the compiler will run out of spill registers and print a fatal error message. For most machines, you should not define this macro at all. +@end defmac -@findex CLASS_LIKELY_SPILLED_P -@item CLASS_LIKELY_SPILLED_P (@var{class}) +@defmac CLASS_LIKELY_SPILLED_P (@var{class}) A C expression whose value is nonzero if pseudos that have been assigned to registers of class @var{class} would likely be spilled because registers of @var{class} are needed for spill registers. @@ -2547,9 +2606,9 @@ register. If there would not be another register available for reallocation, you should not change the definition of this macro since the only effect of such a definition would be to slow down register allocation. +@end defmac -@findex CLASS_MAX_NREGS -@item CLASS_MAX_NREGS (@var{class}, @var{mode}) +@defmac CLASS_MAX_NREGS (@var{class}, @var{mode}) A C expression for the maximum number of consecutive registers of class @var{class} needed to hold a value of mode @var{mode}. @@ -2560,8 +2619,9 @@ should be the maximum value of @code{HARD_REGNO_NREGS (@var{regno}, This macro helps control the handling of multiple-word values in the reload pass. +@end defmac -@item CANNOT_CHANGE_MODE_CLASS(@var{from}, @var{to}, @var{class}) +@defmac CANNOT_CHANGE_MODE_CLASS (@var{from}, @var{to}, @var{class}) If defined, a C expression that returns nonzero for a @var{class} for which a change from mode @var{from} to mode @var{to} is invalid. @@ -2572,19 +2632,17 @@ does not store the low-order 32 bits, as would be the case for a normal register. Therefore, @file{alpha.h} defines @code{CANNOT_CHANGE_MODE_CLASS} as below: -@example +@smallexample #define CANNOT_CHANGE_MODE_CLASS(FROM, TO, CLASS) \ (GET_MODE_SIZE (FROM) != GET_MODE_SIZE (TO) \ ? reg_classes_intersect_p (FLOAT_REGS, (CLASS)) : 0) -@end example -@end table +@end smallexample +@end defmac Three other special macros describe which operands fit which constraint letters. -@table @code -@findex CONST_OK_FOR_LETTER_P -@item CONST_OK_FOR_LETTER_P (@var{value}, @var{c}) +@defmac CONST_OK_FOR_LETTER_P (@var{value}, @var{c}) A C expression that defines the machine-dependent operand constraint letters (@samp{I}, @samp{J}, @samp{K}, @dots{} @samp{P}) that specify particular ranges of integer values. If @var{c} is one of those @@ -2592,9 +2650,15 @@ letters, the expression should check that @var{value}, an integer, is in the appropriate range and return 1 if so, 0 otherwise. If @var{c} is not one of those letters, the value should be 0 regardless of @var{value}. +@end defmac + +@defmac CONST_OK_FOR_CONSTRAINT_P (@var{value}, @var{c}, @var{str}) +Like @code{CONST_OK_FOR_LETTER_P}, but you also get the constraint +string passed in @var{str}, so that you can use suffixes to distinguish +between different variants. +@end defmac -@findex CONST_DOUBLE_OK_FOR_LETTER_P -@item CONST_DOUBLE_OK_FOR_LETTER_P (@var{value}, @var{c}) +@defmac CONST_DOUBLE_OK_FOR_LETTER_P (@var{value}, @var{c}) A C expression that defines the machine-dependent operand constraint letters that specify particular ranges of @code{const_double} values (@samp{G} or @samp{H}). @@ -2608,13 +2672,20 @@ letters, the value should be 0 regardless of @var{value}. @code{DImode} fixed-point constants. A given letter can accept either or both kinds of values. It can use @code{GET_MODE} to distinguish between these kinds. +@end defmac + +@defmac CONST_DOUBLE_OK_FOR_CONSTRAINT_P (@var{value}, @var{c}, @var{str}) +Like @code{CONST_DOUBLE_OK_FOR_LETTER_P}, but you also get the constraint +string passed in @var{str}, so that you can use suffixes to distinguish +between different variants. +@end defmac -@findex EXTRA_CONSTRAINT -@item EXTRA_CONSTRAINT (@var{value}, @var{c}) +@defmac EXTRA_CONSTRAINT (@var{value}, @var{c}) A C expression that defines the optional machine-dependent constraint letters that can be used to segregate specific types of operands, usually memory references, for the target machine. Any letter that is not -elsewhere defined and not matched by @code{REG_CLASS_FROM_LETTER} +elsewhere defined and not matched by @code{REG_CLASS_FROM_LETTER} / +@code{REG_CLASS_FROM_CONSTRAINT} may be used. Normally this macro will not be defined. If it is required for a particular target machine, it should return 1 @@ -2629,17 +2700,24 @@ letter @samp{Q} is defined as representing a memory address that does a @samp{Q} constraint on the input and @samp{r} on the output. The next alternative specifies @samp{m} on the input and a register class that does not include r0 on the output. +@end defmac + +@defmac EXTRA_CONSTRAINT_STR (@var{value}, @var{c}, @var{str}) +Like @code{EXTRA_CONSTRAINT}, but you also get the constraint string passed +in @var{str}, so that you can use suffixes to distinguish between different +variants. +@end defmac -@findex EXTRA_MEMORY_CONSTRAINT -@item EXTRA_MEMORY_CONSTRAINT (@var{c}) +@defmac EXTRA_MEMORY_CONSTRAINT (@var{c}, @var{str}) A C expression that defines the optional machine-dependent constraint letters, amongst those accepted by @code{EXTRA_CONSTRAINT}, that should be treated like memory constraints by the reload pass. -It should return 1 if the operand type represented by the constraint -letter @var{c} comprises a subset of all memory references including -all those whose address is simply a base register. This allows the reload -pass to reload an operand, if it does not directly correspond to the operand +It should return 1 if the operand type represented by the constraint +at the start of @var{str}, the first letter of which is the letter @var{c}, + comprises a subset of all memory references including +all those whose address is simply a base register. This allows the reload +pass to reload an operand, if it does not directly correspond to the operand type of @var{c}, by copying its address into a base register. For example, on the S/390, some instructions do not accept arbitrary @@ -2651,23 +2729,25 @@ a @samp{Q} constraint can handle any memory operand, because the reload pass knows it can be reloaded by copying the memory address into a base register if required. This is analogous to the way a @samp{o} constraint can handle any memory operand. +@end defmac -@findex EXTRA_ADDRESS_CONSTRAINT -@item EXTRA_ADDRESS_CONSTRAINT (@var{c}) +@defmac EXTRA_ADDRESS_CONSTRAINT (@var{c}, @var{str}) A C expression that defines the optional machine-dependent constraint -letters, amongst those accepted by @code{EXTRA_CONSTRAINT}, that should +letters, amongst those accepted by @code{EXTRA_CONSTRAINT} / +@code{EXTRA_CONSTRAINT_STR}, that should be treated like address constraints by the reload pass. -It should return 1 if the operand type represented by the constraint -letter @var{c} comprises a subset of all memory addresses including -all those that consist of just a base register. This allows the reload -pass to reload an operand, if it does not directly correspond to the operand -type of @var{c}, by copying it into a base register. +It should return 1 if the operand type represented by the constraint +at the start of @var{str}, which starts with the letter @var{c}, comprises +a subset of all memory addresses including +all those that consist of just a base register. This allows the reload +pass to reload an operand, if it does not directly correspond to the operand +type of @var{str}, by copying it into a base register. Any constraint marked as @code{EXTRA_ADDRESS_CONSTRAINT} can only -be used with the @code{address_operand} predicate. It is treated +be used with the @code{address_operand} predicate. It is treated analogously to the @samp{p} constraint. -@end table +@end defmac @node Stack and Calling @section Stack Layout and Calling Conventions @@ -2700,19 +2780,16 @@ This describes the stack layout and calling conventions. @c prevent bad page break with this line Here is the basic stack layout. -@table @code -@findex STACK_GROWS_DOWNWARD -@item STACK_GROWS_DOWNWARD +@defmac STACK_GROWS_DOWNWARD Define this macro if pushing a word onto the stack moves the stack pointer to a smaller address. When we say, ``define this macro if @dots{},'' it means that the compiler checks this macro only with @code{#ifdef} so the precise definition used does not matter. +@end defmac -@findex STACK_PUSH_CODE -@item STACK_PUSH_CODE - +@defmac STACK_PUSH_CODE This macro defines the operation used when something is pushed on the stack. In RTL, a push operation will be @code{(set (mem (STACK_PUSH_CODE (reg sp))) @dots{})} @@ -2726,19 +2803,19 @@ space for the next item on the stack. The default is @code{PRE_DEC} when @code{STACK_GROWS_DOWNWARD} is defined, which is almost always right, and @code{PRE_INC} otherwise, which is often wrong. +@end defmac -@findex FRAME_GROWS_DOWNWARD -@item FRAME_GROWS_DOWNWARD +@defmac FRAME_GROWS_DOWNWARD Define this macro if the addresses of local variable slots are at negative offsets from the frame pointer. +@end defmac -@findex ARGS_GROW_DOWNWARD -@item ARGS_GROW_DOWNWARD +@defmac ARGS_GROW_DOWNWARD Define this macro if successive arguments to a function occupy decreasing addresses on the stack. +@end defmac -@findex STARTING_FRAME_OFFSET -@item STARTING_FRAME_OFFSET +@defmac STARTING_FRAME_OFFSET Offset from the frame pointer to the first local variable slot to be allocated. If @code{FRAME_GROWS_DOWNWARD}, find the next slot's offset by @@ -2747,36 +2824,46 @@ Otherwise, it is found by adding the length of the first slot to the value @code{STARTING_FRAME_OFFSET}. @c i'm not sure if the above is still correct.. had to change it to get @c rid of an overfull. --mew 2feb93 +@end defmac + +@defmac STACK_ALIGNMENT_NEEDED +Define to zero to disable final alignment of the stack during reload. +The nonzero default for this macro is suitable for most ports. + +On ports where @code{STARTING_FRAME_OFFSET} is nonzero or where there +is a register save block following the local block that doesn't require +alignment to @code{STACK_BOUNDARY}, it may be beneficial to disable +stack alignment and do it in the backend. +@end defmac -@findex STACK_POINTER_OFFSET -@item STACK_POINTER_OFFSET +@defmac STACK_POINTER_OFFSET Offset from the stack pointer register to the first location at which outgoing arguments are placed. If not specified, the default value of zero is used. This is the proper value for most machines. If @code{ARGS_GROW_DOWNWARD}, this is the offset to the location above the first location at which outgoing arguments are placed. +@end defmac -@findex FIRST_PARM_OFFSET -@item FIRST_PARM_OFFSET (@var{fundecl}) +@defmac FIRST_PARM_OFFSET (@var{fundecl}) Offset from the argument pointer register to the first argument's address. On some machines it may depend on the data type of the function. If @code{ARGS_GROW_DOWNWARD}, this is the offset to the location above the first argument's address. +@end defmac -@findex STACK_DYNAMIC_OFFSET -@item STACK_DYNAMIC_OFFSET (@var{fundecl}) +@defmac STACK_DYNAMIC_OFFSET (@var{fundecl}) Offset from the stack pointer register to an item dynamically allocated on the stack, e.g., by @code{alloca}. The default value for this macro is @code{STACK_POINTER_OFFSET} plus the length of the outgoing arguments. The default is correct for most machines. See @file{function.c} for details. +@end defmac -@findex DYNAMIC_CHAIN_ADDRESS -@item DYNAMIC_CHAIN_ADDRESS (@var{frameaddr}) +@defmac DYNAMIC_CHAIN_ADDRESS (@var{frameaddr}) A C expression whose value is RTL representing the address in a stack frame where the pointer to the caller's frame is stored. Assume that @var{frameaddr} is an RTL expression for the address of the stack frame @@ -2785,25 +2872,25 @@ itself. If you don't define this macro, the default is to return the value of @var{frameaddr}---that is, the stack frame address is also the address of the stack word that points to the previous frame. +@end defmac -@findex SETUP_FRAME_ADDRESSES -@item SETUP_FRAME_ADDRESSES +@defmac SETUP_FRAME_ADDRESSES If defined, a C expression that produces the machine-specific code to setup the stack so that arbitrary frames can be accessed. For example, on the SPARC, we must flush all of the register windows to the stack before we can access arbitrary stack frames. You will seldom need to define this macro. +@end defmac -@findex BUILTIN_SETJMP_FRAME_VALUE -@item BUILTIN_SETJMP_FRAME_VALUE +@defmac BUILTIN_SETJMP_FRAME_VALUE If defined, a C expression that contains an rtx that is used to store the address of the current frame into the built in @code{setjmp} buffer. The default value, @code{virtual_stack_vars_rtx}, is correct for most machines. One reason you may need to define this macro is if @code{hard_frame_pointer_rtx} is the appropriate value on your machine. +@end defmac -@findex RETURN_ADDR_RTX -@item RETURN_ADDR_RTX (@var{count}, @var{frameaddr}) +@defmac RETURN_ADDR_RTX (@var{count}, @var{frameaddr}) A C expression whose value is RTL representing the value of the return address for the frame @var{count} steps up from the current frame, after the prologue. @var{frameaddr} is the frame pointer of the @var{count} @@ -2813,14 +2900,14 @@ frame, or the frame pointer of the @var{count} @minus{} 1 frame if The value of the expression must always be the correct address when @var{count} is zero, but may be @code{NULL_RTX} if there is not way to determine the return address of other frames. +@end defmac -@findex RETURN_ADDR_IN_PREVIOUS_FRAME -@item RETURN_ADDR_IN_PREVIOUS_FRAME +@defmac RETURN_ADDR_IN_PREVIOUS_FRAME Define this if the return address of a particular stack frame is accessed from the frame pointer of the previous stack frame. +@end defmac -@findex INCOMING_RETURN_ADDR_RTX -@item INCOMING_RETURN_ADDR_RTX +@defmac INCOMING_RETURN_ADDR_RTX A C expression whose value is RTL representing the location of the incoming return address at the beginning of any function, before the prologue. This RTL is either a @code{REG}, indicating that the return @@ -2832,9 +2919,17 @@ debugging information like that provided by DWARF 2. If this RTL is a @code{REG}, you should also define @code{DWARF_FRAME_RETURN_COLUMN} to @code{DWARF_FRAME_REGNUM (REGNO)}. +@end defmac -@findex INCOMING_FRAME_SP_OFFSET -@item INCOMING_FRAME_SP_OFFSET +@defmac DWARF_ALT_FRAME_RETURN_COLUMN +A C expression whose value is an integer giving a DWARF 2 column +number that may be used as an alternate return column. This should +be defined only if @code{DWARF_FRAME_RETURN_COLUMN} is set to a +general register, but an alternate column needs to be used for +signal frames. +@end defmac + +@defmac INCOMING_FRAME_SP_OFFSET A C expression whose value is an integer giving the offset, in bytes, from the value of the stack pointer register to the top of the stack frame at the beginning of any function, before the prologue. The top of @@ -2843,9 +2938,9 @@ previous frame, just before the call instruction. You only need to define this macro if you want to support call frame debugging information like that provided by DWARF 2. +@end defmac -@findex ARG_POINTER_CFA_OFFSET -@item ARG_POINTER_CFA_OFFSET (@var{fundecl}) +@defmac ARG_POINTER_CFA_OFFSET (@var{fundecl}) A C expression whose value is an integer giving the offset, in bytes, from the argument pointer to the canonical frame address (cfa). The final value should coincide with that calculated by @@ -2861,21 +2956,13 @@ and rs6000, and so such targets need to define this macro. You only need to define this macro if the default is incorrect, and you want to support call frame debugging information like that provided by DWARF 2. - -@findex SMALL_STACK -@item SMALL_STACK -Define this macro if the stack size for the target is very small. This -has the effect of disabling gcc's built-in @samp{alloca}, though -@samp{__builtin_alloca} is not affected. -@end table +@end defmac @node Exception Handling @subsection Exception Handling Support @cindex exception handling -@table @code -@findex EH_RETURN_DATA_REGNO -@item EH_RETURN_DATA_REGNO (@var{N}) +@defmac EH_RETURN_DATA_REGNO (@var{N}) A C expression whose value is the @var{N}th register number used for data by exception handlers, or @code{INVALID_REGNUM} if fewer than @var{N} registers are usable. @@ -2888,9 +2975,9 @@ but may negatively impact code size. The target must support at least You must define this macro if you want to support call frame exception handling like that provided by DWARF 2. +@end defmac -@findex EH_RETURN_STACKADJ_RTX -@item EH_RETURN_STACKADJ_RTX +@defmac EH_RETURN_STACKADJ_RTX A C expression whose value is RTL representing a location in which to store a stack adjustment to be applied before function return. This is used to unwind the stack to an exception handler's call frame. @@ -2900,14 +2987,14 @@ Typically this is a call-clobbered hard register that is otherwise untouched by the epilogue, but could also be a stack slot. Do not define this macro if the stack pointer is saved and restored -by the regular prolog and epilog code in the call frame itself; in -this case, the exception handling library routines will update the -stack location to be restored in place. Otherwise, you must define -this macro if you want to support call frame exception handling like +by the regular prolog and epilog code in the call frame itself; in +this case, the exception handling library routines will update the +stack location to be restored in place. Otherwise, you must define +this macro if you want to support call frame exception handling like that provided by DWARF 2. +@end defmac -@findex EH_RETURN_HANDLER_RTX -@item EH_RETURN_HANDLER_RTX +@defmac EH_RETURN_HANDLER_RTX A C expression whose value is RTL representing a location in which to store the address of an exception handler to which we should return. It will not be assigned on code paths that return normally. @@ -2916,8 +3003,8 @@ Typically this is the location in the call frame at which the normal return address is stored. For targets that return by popping an address off the stack, this might be a memory address just below the @emph{target} call frame rather than inside the current call -frame. If defined, @code{EH_RETURN_STACKADJ_RTX} will have already -been assigned, so it may be used to calculate the location of the +frame. If defined, @code{EH_RETURN_STACKADJ_RTX} will have already +been assigned, so it may be used to calculate the location of the target call frame. Some targets have more complex requirements than storing to an @@ -2926,9 +3013,16 @@ the @code{eh_return} instruction pattern should be used instead. If you want to support call frame exception handling, you must define either this macro or the @code{eh_return} instruction pattern. +@end defmac -@findex ASM_PREFERRED_EH_DATA_FORMAT -@item ASM_PREFERRED_EH_DATA_FORMAT(@var{code}, @var{global}) +@defmac RETURN_ADDR_OFFSET +If defined, an integer-valued C expression for which rtl will be generated +to add it to the exception handler address before it is searched in the +exception handling tables, and to subtract it again from the address before +using it to return to the exception handler. +@end defmac + +@defmac ASM_PREFERRED_EH_DATA_FORMAT (@var{code}, @var{global}) This macro chooses the encoding of pointers embedded in the exception handling sections. If at all possible, this should be defined such that the exception handling section will not require dynamic relocations, @@ -2941,9 +3035,9 @@ as found in @file{dwarf2.h}. If this macro is not defined, pointers will not be encoded but represented directly. +@end defmac -@findex ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX -@item ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX(@var{file}, @var{encoding}, @var{size}, @var{addr}, @var{done}) +@defmac ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX (@var{file}, @var{encoding}, @var{size}, @var{addr}, @var{done}) This macro allows the target to emit whatever special magic is required to represent the encoding chosen by @code{ASM_PREFERRED_EH_DATA_FORMAT}. Generic code takes care of pc-relative and indirect encodings; this must @@ -2953,9 +3047,9 @@ This is a C statement that branches to @var{done} if the format was handled. @var{encoding} is the format chosen, @var{size} is the number of bytes that the format occupies, @var{addr} is the @code{SYMBOL_REF} to be emitted. +@end defmac -@findex MD_FALLBACK_FRAME_STATE_FOR -@item MD_FALLBACK_FRAME_STATE_FOR(@var{context}, @var{fs}, @var{success}) +@defmac MD_FALLBACK_FRAME_STATE_FOR (@var{context}, @var{fs}, @var{success}) This macro allows the target to add cpu and operating system specific code to the call-frame unwinder for use when there is no unwind data available. The most common reason to implement this macro is to unwind @@ -2969,7 +3063,23 @@ the stack pointer value. If the frame can be decoded, the register save addresses should be updated in @var{fs} and the macro should branch to @var{success}. If the frame cannot be decoded, the macro should do nothing. -@end table + +For proper signal handling in Java this macro is accompanied by +@code{MAKE_THROW_FRAME}, defined in @file{libjava/include/*-signal.h} headers. +@end defmac + +@defmac MD_HANDLE_UNWABI (@var{context}, @var{fs}) +This macro allows the target to add operating system specific code to the +call-frame unwinder to handle the IA-64 @code{.unwabi} unwinding directive, +usually used for signal or interrupt frames. + +This macro is called from @code{uw_update_context} in @file{unwind-ia64.c}. +@var{context} is an @code{_Unwind_Context}; +@var{fs} is an @code{_Unwind_FrameState}. Examine @code{fs->unwabi} +for the abi and context in the @code{.unwabi} directive. If the +@code{.unwabi} directive can be handled, the register save addresses should +be updated in @var{fs}. +@end defmac @node Stack Checking @subsection Specifying How Stack Checking is Done @@ -3000,59 +3110,57 @@ If neither of the above are true, GCC will generate code to periodically Normally, you will use the default values of these macros, so GCC will use the third approach. -@table @code -@findex STACK_CHECK_BUILTIN -@item STACK_CHECK_BUILTIN +@defmac STACK_CHECK_BUILTIN A nonzero value if stack checking is done by the configuration files in a machine-dependent manner. You should define this macro if stack checking is require by the ABI of your machine or if you would like to have to stack checking in some more efficient way than GCC's portable approach. The default value of this macro is zero. +@end defmac -@findex STACK_CHECK_PROBE_INTERVAL -@item STACK_CHECK_PROBE_INTERVAL +@defmac STACK_CHECK_PROBE_INTERVAL An integer representing the interval at which GCC must generate stack probe instructions. You will normally define this macro to be no larger than the size of the ``guard pages'' at the end of a stack area. The default value of 4096 is suitable for most systems. +@end defmac -@findex STACK_CHECK_PROBE_LOAD -@item STACK_CHECK_PROBE_LOAD +@defmac STACK_CHECK_PROBE_LOAD A integer which is nonzero if GCC should perform the stack probe as a load instruction and zero if GCC should use a store instruction. The default is zero, which is the most efficient choice on most systems. +@end defmac -@findex STACK_CHECK_PROTECT -@item STACK_CHECK_PROTECT +@defmac STACK_CHECK_PROTECT The number of bytes of stack needed to recover from a stack overflow, for languages where such a recovery is supported. The default value of 75 words should be adequate for most machines. +@end defmac -@findex STACK_CHECK_MAX_FRAME_SIZE -@item STACK_CHECK_MAX_FRAME_SIZE +@defmac STACK_CHECK_MAX_FRAME_SIZE The maximum size of a stack frame, in bytes. GCC will generate probe instructions in non-leaf functions to ensure at least this many bytes of stack are available. If a stack frame is larger than this size, stack checking will not be reliable and GCC will issue a warning. The default is chosen so that GCC only generates one instruction on most systems. You should normally not change the default value of this macro. +@end defmac -@findex STACK_CHECK_FIXED_FRAME_SIZE -@item STACK_CHECK_FIXED_FRAME_SIZE +@defmac STACK_CHECK_FIXED_FRAME_SIZE GCC uses this value to generate the above warning message. It represents the amount of fixed frame used by a function, not including space for any callee-saved registers, temporaries and user variables. You need only specify an upper bound for this amount and will normally use the default of four words. +@end defmac -@findex STACK_CHECK_MAX_VAR_SIZE -@item STACK_CHECK_MAX_VAR_SIZE +@defmac STACK_CHECK_MAX_VAR_SIZE The maximum size, in bytes, of an object that GCC will place in the fixed area of the stack frame when the user specifies @option{-fstack-check}. GCC computed the default from the values of the above macros and you will normally not need to override that default. -@end table +@end defmac @need 2000 @node Frame Registers @@ -3061,22 +3169,20 @@ normally not need to override that default. @c prevent bad page break with this line This discusses registers that address the stack frame. -@table @code -@findex STACK_POINTER_REGNUM -@item STACK_POINTER_REGNUM +@defmac STACK_POINTER_REGNUM The register number of the stack pointer register, which must also be a fixed register according to @code{FIXED_REGISTERS}. On most machines, the hardware determines which register this is. +@end defmac -@findex FRAME_POINTER_REGNUM -@item FRAME_POINTER_REGNUM +@defmac FRAME_POINTER_REGNUM The register number of the frame pointer register, which is used to access automatic variables in the stack frame. On some machines, the hardware determines which register this is. On other machines, you can choose any register you wish for this purpose. +@end defmac -@findex HARD_FRAME_POINTER_REGNUM -@item HARD_FRAME_POINTER_REGNUM +@defmac HARD_FRAME_POINTER_REGNUM On some machines the offset between the frame pointer and starting offset of the automatic variables is not known until after register allocation has been done (for example, because the saved registers are @@ -3096,9 +3202,9 @@ or @code{STACK_POINTER_REGNUM}. Do not define this macro if it would be the same as @code{FRAME_POINTER_REGNUM}. +@end defmac -@findex ARG_POINTER_REGNUM -@item ARG_POINTER_REGNUM +@defmac ARG_POINTER_REGNUM The register number of the arg pointer register, which is used to access the function's argument list. On some machines, this is the same as the frame pointer register. On some machines, the hardware determines which @@ -3107,9 +3213,9 @@ wish for this purpose. If this is not the same register as the frame pointer register, then you must mark it as a fixed register according to @code{FIXED_REGISTERS}, or arrange to be able to eliminate it (@pxref{Elimination}). +@end defmac -@findex RETURN_ADDRESS_POINTER_REGNUM -@item RETURN_ADDRESS_POINTER_REGNUM +@defmac RETURN_ADDRESS_POINTER_REGNUM The register number of the return address pointer register, which is used to access the current function's return address from the stack. On some machines, the return address is not at a fixed offset from the frame @@ -3119,11 +3225,10 @@ to point to the return address on the stack, and then be converted by Do not define this macro unless there is no other way to get the return address from the stack. +@end defmac -@findex STATIC_CHAIN_REGNUM -@findex STATIC_CHAIN_INCOMING_REGNUM -@item STATIC_CHAIN_REGNUM -@itemx STATIC_CHAIN_INCOMING_REGNUM +@defmac STATIC_CHAIN_REGNUM +@defmacx STATIC_CHAIN_INCOMING_REGNUM Register numbers used for passing a function's static chain pointer. If register windows are used, the register number as seen by the called function is @code{STATIC_CHAIN_INCOMING_REGNUM}, while the register @@ -3135,11 +3240,10 @@ The static chain register need not be a fixed register. If the static chain is passed in memory, these macros should not be defined; instead, the next two macros should be defined. +@end defmac -@findex STATIC_CHAIN -@findex STATIC_CHAIN_INCOMING -@item STATIC_CHAIN -@itemx STATIC_CHAIN_INCOMING +@defmac STATIC_CHAIN +@defmacx STATIC_CHAIN_INCOMING If the static chain is passed in memory, these macros provide rtx giving @code{mem} expressions that denote where they are stored. @code{STATIC_CHAIN} and @code{STATIC_CHAIN_INCOMING} give the locations @@ -3156,9 +3260,9 @@ macros and should be used to refer to those items. If the static chain is passed in a register, the two previous macros should be defined instead. +@end defmac -@findex DWARF_FRAME_REGISTERS -@item DWARF_FRAME_REGISTERS +@defmac DWARF_FRAME_REGISTERS This macro specifies the maximum number of hard registers that can be saved in a call frame. This is used to size data structures used in DWARF2 exception handling. @@ -3173,17 +3277,46 @@ registers that are not call-saved. If this macro is not defined, it defaults to @code{FIRST_PSEUDO_REGISTER}. +@end defmac -@findex PRE_GCC3_DWARF_FRAME_REGISTERS -@item PRE_GCC3_DWARF_FRAME_REGISTERS +@defmac PRE_GCC3_DWARF_FRAME_REGISTERS This macro is similar to @code{DWARF_FRAME_REGISTERS}, but is provided for backward compatibility in pre GCC 3.0 compiled code. If this macro is not defined, it defaults to @code{DWARF_FRAME_REGISTERS}. +@end defmac -@end table +@defmac DWARF_REG_TO_UNWIND_COLUMN (@var{regno}) + +Define this macro if the target's representation for dwarf registers +is different than the internal representation for unwind column. +Given a dwarf register, this macro should return the internal unwind +column number to use instead. + +See the PowerPC's SPE target for an example. +@end defmac + +@defmac DWARF_FRAME_REGNUM (@var{regno}) + +Define this macro if the target's representation for dwarf registers +used in .eh_frame or .debug_frame is different from that used in other +debug info sections. Given a GCC hard register number, this macro +should return the .eh_frame register number. The default is +@code{DBX_REGISTER_NUMBER (@var{regno})}. + +@end defmac + +@defmac DWARF2_FRAME_REG_OUT (@var{regno}, @var{for_eh}) + +Define this macro to map register numbers held in the call frame info +that GCC has collected using @code{DWARF_FRAME_REGNUM} to those that +should be output in .debug_frame (@code{@var{for_eh}} is zero) and +.eh_frame (@code{@var{for_eh}} is nonzero). The default is to +return @code{@var{regno}}. + +@end defmac @node Elimination @subsection Eliminating Frame Pointer and Arg Pointer @@ -3191,9 +3324,7 @@ If this macro is not defined, it defaults to @c prevent bad page break with this line This is about eliminating the frame pointer and arg pointer. -@table @code -@findex FRAME_POINTER_REQUIRED -@item FRAME_POINTER_REQUIRED +@defmac FRAME_POINTER_REQUIRED A C expression which is nonzero if a function must have and use a frame pointer. This expression is evaluated in the reload pass. If its value is nonzero the function will have a frame pointer. @@ -3213,10 +3344,10 @@ them. In a function that does not require a frame pointer, the frame pointer register can be allocated for ordinary usage, unless you mark it as a fixed register. See @code{FIXED_REGISTERS} for more information. +@end defmac -@findex INITIAL_FRAME_POINTER_OFFSET @findex get_frame_size -@item INITIAL_FRAME_POINTER_OFFSET (@var{depth-var}) +@defmac INITIAL_FRAME_POINTER_OFFSET (@var{depth-var}) A C statement to store in the variable @var{depth-var} the difference between the frame pointer and the stack pointer values immediately after the function prologue. The value would be computed from information @@ -3227,9 +3358,9 @@ If @code{ELIMINABLE_REGS} is defined, this macro will be not be used and need not be defined. Otherwise, it must be defined even if @code{FRAME_POINTER_REQUIRED} is defined to always be true; in that case, you may set @var{depth-var} to anything. +@end defmac -@findex ELIMINABLE_REGS -@item ELIMINABLE_REGS +@defmac ELIMINABLE_REGS If defined, this macro specifies a table of register pairs used to eliminate unneeded registers that point into the stack frame. If it is not defined, the only elimination attempted by the compiler is to replace @@ -3245,32 +3376,32 @@ replacing it with either the frame pointer or the argument pointer, depending on whether or not the frame pointer has been eliminated. In this case, you might specify: -@example +@smallexample #define ELIMINABLE_REGS \ @{@{ARG_POINTER_REGNUM, STACK_POINTER_REGNUM@}, \ @{ARG_POINTER_REGNUM, FRAME_POINTER_REGNUM@}, \ @{FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM@}@} -@end example +@end smallexample Note that the elimination of the argument pointer with the stack pointer is specified first since that is the preferred elimination. +@end defmac -@findex CAN_ELIMINATE -@item CAN_ELIMINATE (@var{from-reg}, @var{to-reg}) +@defmac CAN_ELIMINATE (@var{from-reg}, @var{to-reg}) A C expression that returns nonzero if the compiler is allowed to try to replace register number @var{from-reg} with register number @var{to-reg}. This macro need only be defined if @code{ELIMINABLE_REGS} is defined, and will usually be the constant 1, since most of the cases preventing register elimination are things that the compiler already knows about. +@end defmac -@findex INITIAL_ELIMINATION_OFFSET -@item INITIAL_ELIMINATION_OFFSET (@var{from-reg}, @var{to-reg}, @var{offset-var}) +@defmac INITIAL_ELIMINATION_OFFSET (@var{from-reg}, @var{to-reg}, @var{offset-var}) This macro is similar to @code{INITIAL_FRAME_POINTER_OFFSET}. It specifies the initial difference between the specified pair of registers. This macro must be defined if @code{ELIMINABLE_REGS} is defined. -@end table +@end defmac @node Stack Arguments @subsection Passing Function Arguments on the Stack @@ -3281,48 +3412,52 @@ The macros in this section control how arguments are passed on the stack. See the following section for other macros that control passing certain arguments in registers. -@table @code -@findex PROMOTE_PROTOTYPES -@item PROMOTE_PROTOTYPES -A C expression whose value is nonzero if an argument declared in -a prototype as an integral type smaller than @code{int} should -actually be passed as an @code{int}. In addition to avoiding -errors in certain cases of mismatch, it also makes for better -code on certain machines. If the macro is not defined in target -header files, it defaults to 0. - -@findex PUSH_ARGS -@item PUSH_ARGS +@deftypefn {Target Hook} bool TARGET_PROMOTE_PROTOTYPES (tree @var{fntype}) +This target hook returns @code{true} if an argument declared in a +prototype as an integral type smaller than @code{int} should actually be +passed as an @code{int}. In addition to avoiding errors in certain +cases of mismatch, it also makes for better code on certain machines. +The default is to not promote prototypes. +@end deftypefn + +@defmac PUSH_ARGS A C expression. If nonzero, push insns will be used to pass outgoing arguments. If the target machine does not have a push instruction, set it to zero. That directs GCC to use an alternate strategy: to allocate the entire argument block and then store the arguments into it. When @code{PUSH_ARGS} is nonzero, @code{PUSH_ROUNDING} must be defined too. +@end defmac -@findex PUSH_ROUNDING -@item PUSH_ROUNDING (@var{npushed}) +@defmac PUSH_ARGS_REVERSED +A C expression. If nonzero, function arguments will be evaluated from +last to first, rather than from first to last. If this macro is not +defined, it defaults to @code{PUSH_ARGS} on targets where the stack +and args grow in opposite directions, and 0 otherwise. +@end defmac + +@defmac PUSH_ROUNDING (@var{npushed}) A C expression that is the number of bytes actually pushed onto the stack when an instruction attempts to push @var{npushed} bytes. On some machines, the definition -@example +@smallexample #define PUSH_ROUNDING(BYTES) (BYTES) -@end example +@end smallexample @noindent will suffice. But on other machines, instructions that appear to push one byte actually push two bytes in an attempt to maintain alignment. Then the definition should be -@example +@smallexample #define PUSH_ROUNDING(BYTES) (((BYTES) + 1) & ~1) -@end example +@end smallexample +@end defmac -@findex ACCUMULATE_OUTGOING_ARGS @findex current_function_outgoing_args_size -@item ACCUMULATE_OUTGOING_ARGS +@defmac ACCUMULATE_OUTGOING_ARGS A C expression. If nonzero, the maximum amount of space required for outgoing arguments will be computed and placed into the variable @code{current_function_outgoing_args_size}. No space will be pushed @@ -3331,9 +3466,9 @@ increase the stack frame size by this amount. Setting both @code{PUSH_ARGS} and @code{ACCUMULATE_OUTGOING_ARGS} is not proper. +@end defmac -@findex REG_PARM_STACK_SPACE -@item REG_PARM_STACK_SPACE (@var{fndecl}) +@defmac REG_PARM_STACK_SPACE (@var{fndecl}) Define this macro if functions should assume that stack space has been allocated for arguments even when their values are passed in registers. @@ -3345,13 +3480,12 @@ which can be zero if GCC is calling a library function. This space can be allocated by the caller, or be a part of the machine-dependent stack frame: @code{OUTGOING_REG_PARM_STACK_SPACE} says which. +@end defmac @c above is overfull. not sure what to do. --mew 5feb93 did @c something, not sure if it looks good. --mew 10feb93 -@findex MAYBE_REG_PARM_STACK_SPACE -@findex FINAL_REG_PARM_STACK_SPACE -@item MAYBE_REG_PARM_STACK_SPACE -@itemx FINAL_REG_PARM_STACK_SPACE (@var{const_size}, @var{var_size}) +@defmac MAYBE_REG_PARM_STACK_SPACE +@defmacx FINAL_REG_PARM_STACK_SPACE (@var{const_size}, @var{var_size}) Define these macros in addition to the one above if functions might allocate stack space for arguments even when their values are passed in registers. These should be used when the stack space allocated @@ -3375,18 +3509,18 @@ In each case this value can be easily computed. When deciding whether a called function needs such stack space, and how much space to reserve, GCC uses these two macros instead of @code{REG_PARM_STACK_SPACE}. +@end defmac -@findex OUTGOING_REG_PARM_STACK_SPACE -@item OUTGOING_REG_PARM_STACK_SPACE +@defmac OUTGOING_REG_PARM_STACK_SPACE Define this if it is the responsibility of the caller to allocate the area reserved for arguments passed in registers. If @code{ACCUMULATE_OUTGOING_ARGS} is defined, this macro controls whether the space for these arguments counts in the value of @code{current_function_outgoing_args_size}. +@end defmac -@findex STACK_PARMS_IN_REG_PARM_AREA -@item STACK_PARMS_IN_REG_PARM_AREA +@defmac STACK_PARMS_IN_REG_PARM_AREA Define this macro if @code{REG_PARM_STACK_SPACE} is defined, but the stack parameters don't skip the area specified by it. @c i changed this, makes more sens and it should have taken care of the @@ -3396,9 +3530,9 @@ Normally, when a parameter is not passed in registers, it is placed on the stack beyond the @code{REG_PARM_STACK_SPACE} area. Defining this macro suppresses this behavior and causes the parameter to be passed on the stack in its natural location. +@end defmac -@findex RETURN_POPS_ARGS -@item RETURN_POPS_ARGS (@var{fundecl}, @var{funtype}, @var{stack-size}) +@defmac RETURN_POPS_ARGS (@var{fundecl}, @var{funtype}, @var{stack-size}) A C expression that should indicate the number of bytes of its own arguments that a function pops on returning, or 0 if the function pops no arguments and the caller must therefore pop them all @@ -3435,9 +3569,9 @@ arguments pop them but other functions (such as @code{printf}) pop nothing (the caller pops all). When this convention is in use, @var{funtype} is examined to determine whether a function takes a fixed number of arguments. +@end defmac -@findex CALL_POPS_ARGS -@item CALL_POPS_ARGS (@var{cum}) +@defmac CALL_POPS_ARGS (@var{cum}) A C expression that should indicate the number of bytes a call sequence pops off the stack. It is added to the value of @code{RETURN_POPS_ARGS} when compiling a function call. @@ -3450,8 +3584,7 @@ that pops certain registers off the stack, depending on the arguments that have been passed to the function. Since this is a property of the call site, not of the called function, @code{RETURN_POPS_ARGS} is not appropriate. - -@end table +@end defmac @node Register Arguments @subsection Passing Arguments in Registers @@ -3462,9 +3595,7 @@ This section describes the macros which let you control how various types of arguments are passed in registers or how they are arranged in the stack. -@table @code -@findex FUNCTION_ARG -@item FUNCTION_ARG (@var{cum}, @var{mode}, @var{type}, @var{named}) +@defmac FUNCTION_ARG (@var{cum}, @var{mode}, @var{type}, @var{named}) A C expression that controls whether a function argument is passed in a register, and which register. @@ -3486,7 +3617,7 @@ pushed, zero suffices as a definition. The value of the expression can also be a @code{parallel} RTX@. This is used when an argument is passed in multiple locations. The mode of the -of the @code{parallel} should be the mode of the entire argument. The +@code{parallel} should be the mode of the entire argument. The @code{parallel} holds any number of @code{expr_list} pairs; each one describes where part of the argument is passed. In each @code{expr_list} the first operand must be a @code{reg} RTX for the hard @@ -3517,16 +3648,16 @@ is not defined and @code{FUNCTION_ARG} returns nonzero for such an argument, the compiler will abort. If @code{REG_PARM_STACK_SPACE} is defined, the argument will be computed in the stack and then loaded into a register. +@end defmac -@findex MUST_PASS_IN_STACK -@item MUST_PASS_IN_STACK (@var{mode}, @var{type}) +@defmac MUST_PASS_IN_STACK (@var{mode}, @var{type}) Define as a C expression that evaluates to nonzero if we do not know how to pass TYPE solely in registers. The file @file{expr.h} defines a definition that is usually appropriate, refer to @file{expr.h} for additional documentation. +@end defmac -@findex FUNCTION_INCOMING_ARG -@item FUNCTION_INCOMING_ARG (@var{cum}, @var{mode}, @var{type}, @var{named}) +@defmac FUNCTION_INCOMING_ARG (@var{cum}, @var{mode}, @var{type}, @var{named}) Define this macro if the target machine has ``register windows'', so that the register in which a function sees an arguments is not necessarily the same as the one in which the caller passed the @@ -3539,9 +3670,9 @@ where the arguments will arrive. If @code{FUNCTION_INCOMING_ARG} is not defined, @code{FUNCTION_ARG} serves both purposes. +@end defmac -@findex FUNCTION_ARG_PARTIAL_NREGS -@item FUNCTION_ARG_PARTIAL_NREGS (@var{cum}, @var{mode}, @var{type}, @var{named}) +@defmac FUNCTION_ARG_PARTIAL_NREGS (@var{cum}, @var{mode}, @var{type}, @var{named}) A C expression for the number of words, at the beginning of an argument, that must be put in registers. The value must be zero for arguments that are passed entirely in registers or that are entirely @@ -3559,9 +3690,9 @@ registers. @code{FUNCTION_ARG} for these arguments should return the first register to be used by the caller for this argument; likewise @code{FUNCTION_INCOMING_ARG}, for the called function. +@end defmac -@findex FUNCTION_ARG_PASS_BY_REFERENCE -@item FUNCTION_ARG_PASS_BY_REFERENCE (@var{cum}, @var{mode}, @var{type}, @var{named}) +@defmac FUNCTION_ARG_PASS_BY_REFERENCE (@var{cum}, @var{mode}, @var{type}, @var{named}) A C expression that indicates when an argument must be passed by reference. If nonzero for an argument, a copy of that argument is made in memory and a pointer to the argument is passed instead of the argument itself. @@ -3576,9 +3707,9 @@ definition of this macro might be MUST_PASS_IN_STACK (MODE, TYPE) @end smallexample @c this is *still* too long. --mew 5feb93 +@end defmac -@findex FUNCTION_ARG_CALLEE_COPIES -@item FUNCTION_ARG_CALLEE_COPIES (@var{cum}, @var{mode}, @var{type}, @var{named}) +@defmac FUNCTION_ARG_CALLEE_COPIES (@var{cum}, @var{mode}, @var{type}, @var{named}) If defined, a C expression that indicates when it is the called function's responsibility to make a copy of arguments passed by invisible reference. Normally, the caller makes a copy and passes the address of the copy to the @@ -3587,9 +3718,9 @@ nonzero, the caller does not make a copy. Instead, it passes a pointer to the ``live'' value. The called function must not modify this value. If it can be determined that the value won't be modified, it need not make a copy; otherwise a copy must be made. +@end defmac -@findex CUMULATIVE_ARGS -@item CUMULATIVE_ARGS +@defmac CUMULATIVE_ARGS A C type for declaring a variable that is used as the first argument of @code{FUNCTION_ARG} and other related values. For some target machines, the type @code{int} suffices and can hold the number of bytes of @@ -3601,19 +3732,21 @@ variables to keep track of that. For target machines on which all arguments are passed on the stack, there is no need to store anything in @code{CUMULATIVE_ARGS}; however, the data structure must exist and should not be empty, so use @code{int}. +@end defmac -@findex INIT_CUMULATIVE_ARGS -@item INIT_CUMULATIVE_ARGS (@var{cum}, @var{fntype}, @var{libname}, @var{indirect}) -A C statement (sans semicolon) for initializing the variable @var{cum} -for the state at the beginning of the argument list. The variable has -type @code{CUMULATIVE_ARGS}. The value of @var{fntype} is the tree node -for the data type of the function which will receive the args, or 0 -if the args are to a compiler support library function. The value of -@var{indirect} is nonzero when processing an indirect call, for example -a call through a function pointer. The value of @var{indirect} is zero -for a call to an explicitly named function, a library function call, or when +@defmac INIT_CUMULATIVE_ARGS (@var{cum}, @var{fntype}, @var{libname}, @var{fndecl}, @var{n_named_args}) +A C statement (sans semicolon) for initializing the variable +@var{cum} for the state at the beginning of the argument list. The +variable has type @code{CUMULATIVE_ARGS}. The value of @var{fntype} +is the tree node for the data type of the function which will receive +the args, or 0 if the args are to a compiler support library function. +For direct calls that are not libcalls, @var{fndecl} contain the +declaration node of the function. @var{fndecl} is also set when @code{INIT_CUMULATIVE_ARGS} is used to find arguments for the function -being compiled. +being compiled. @var{n_named_args} is set to the number of named +arguments, including a structure return address if it is passed as a +parameter, when making a call. When processing incoming arguments, +@var{n_named_args} is set to -1. When processing a call to a compiler support library function, @var{libname} identifies which one. It is a @code{symbol_ref} rtx which @@ -3621,17 +3754,17 @@ contains the name of the function, as a string. @var{libname} is 0 when an ordinary C function call is being processed. Thus, each time this macro is called, either @var{libname} or @var{fntype} is nonzero, but never both of them at once. +@end defmac -@findex INIT_CUMULATIVE_LIBCALL_ARGS -@item INIT_CUMULATIVE_LIBCALL_ARGS (@var{cum}, @var{mode}, @var{libname}) +@defmac INIT_CUMULATIVE_LIBCALL_ARGS (@var{cum}, @var{mode}, @var{libname}) Like @code{INIT_CUMULATIVE_ARGS} but only used for outgoing libcalls, it gets a @code{MODE} argument instead of @var{fntype}, that would be @code{NULL}. @var{indirect} would always be zero, too. If this macro is not defined, @code{INIT_CUMULATIVE_ARGS (cum, NULL_RTX, libname, 0)} is used instead. +@end defmac -@findex INIT_CUMULATIVE_INCOMING_ARGS -@item INIT_CUMULATIVE_INCOMING_ARGS (@var{cum}, @var{fntype}, @var{libname}) +@defmac INIT_CUMULATIVE_INCOMING_ARGS (@var{cum}, @var{fntype}, @var{libname}) Like @code{INIT_CUMULATIVE_ARGS} but overrides it for the purposes of finding the arguments for the function being compiled. If this macro is undefined, @code{INIT_CUMULATIVE_ARGS} is used instead. @@ -3642,9 +3775,9 @@ argument @var{libname} exists for symmetry with @code{INIT_CUMULATIVE_ARGS}. @c could use "this macro" in place of @code{INIT_CUMULATIVE_ARGS}, maybe. @c --mew 5feb93 i switched the order of the sentences. --mew 10feb93 +@end defmac -@findex FUNCTION_ARG_ADVANCE -@item FUNCTION_ARG_ADVANCE (@var{cum}, @var{mode}, @var{type}, @var{named}) +@defmac FUNCTION_ARG_ADVANCE (@var{cum}, @var{mode}, @var{type}, @var{named}) A C statement (sans semicolon) to update the summarizer variable @var{cum} to advance past an argument in the argument list. The values @var{mode}, @var{type} and @var{named} describe that argument. @@ -3654,9 +3787,9 @@ the @emph{following} argument with @code{FUNCTION_ARG}, etc. This macro need not do anything if the argument in question was passed on the stack. The compiler knows how to track the amount of stack space used for arguments without any special help. +@end defmac -@findex FUNCTION_ARG_PADDING -@item FUNCTION_ARG_PADDING (@var{mode}, @var{type}) +@defmac FUNCTION_ARG_PADDING (@var{mode}, @var{type}) If defined, a C expression which determines whether, and in which direction, to pad out an argument with extra space. The value should be of type @code{enum direction}: either @code{upward} to pad above the argument, @@ -3670,38 +3803,54 @@ This macro has a default definition which is right for most systems. For little-endian machines, the default is to pad upward. For big-endian machines, the default is to pad downward for an argument of constant size shorter than an @code{int}, and upward otherwise. +@end defmac -@findex PAD_VARARGS_DOWN -@item PAD_VARARGS_DOWN +@defmac PAD_VARARGS_DOWN If defined, a C expression which determines whether the default implementation of va_arg will attempt to pad down before reading the next argument, if that argument is smaller than its aligned space as controlled by @code{PARM_BOUNDARY}. If this macro is not defined, all such arguments are padded down if @code{BYTES_BIG_ENDIAN} is true. +@end defmac -@findex FUNCTION_ARG_BOUNDARY -@item FUNCTION_ARG_BOUNDARY (@var{mode}, @var{type}) +@defmac BLOCK_REG_PADDING (@var{mode}, @var{type}, @var{first}) +Specify padding for the last element of a block move between registers and +memory. @var{first} is nonzero if this is the only element. Defining this +macro allows better control of register function parameters on big-endian +machines, without using @code{PARALLEL} rtl. In particular, +@code{MUST_PASS_IN_STACK} need not test padding and mode of types in +registers, as there is no longer a "wrong" part of a register; For example, +a three byte aggregate may be passed in the high part of a register if so +required. +@end defmac + +@defmac FUNCTION_ARG_BOUNDARY (@var{mode}, @var{type}) If defined, a C expression that gives the alignment boundary, in bits, of an argument with the specified mode and type. If it is not defined, @code{PARM_BOUNDARY} is used for all arguments. +@end defmac -@findex FUNCTION_ARG_REGNO_P -@item FUNCTION_ARG_REGNO_P (@var{regno}) +@defmac FUNCTION_ARG_REGNO_P (@var{regno}) A C expression that is nonzero if @var{regno} is the number of a hard register in which function arguments are sometimes passed. This does @emph{not} include implicit arguments such as the static chain and the structure-value address. On many machines, no registers can be used for this purpose since all function arguments are pushed on the stack. +@end defmac -@findex LOAD_ARGS_REVERSED -@item LOAD_ARGS_REVERSED -If defined, the order in which arguments are loaded into their -respective argument registers is reversed so that the last -argument is loaded first. This macro only affects arguments -passed in registers. - -@end table +@deftypefn {Target Hook} bool TARGET_SPLIT_COMPLEX_ARG (tree @var{type}) +This hook should return true if parameter of type @var{type} are passed +as two scalar parameters. By default, GCC will attempt to pack complex +arguments into the target's word size. Some ABIs require complex arguments +to be split and treated as their individual components. For example, on +AIX64, complex floats should be passed in a pair of floating point +registers, even though a complex float would fit in one 64-bit floating +point register. + +The default value of this hook is @code{NULL}, which is treated as always +false. +@end deftypefn @node Scalar Return @subsection How Scalar Function Values Are Returned @@ -3712,9 +3861,7 @@ passed in registers. This section discusses the macros that control returning scalars as values---values that can fit in registers. -@table @code -@findex FUNCTION_VALUE -@item FUNCTION_VALUE (@var{valtype}, @var{func}) +@defmac FUNCTION_VALUE (@var{valtype}, @var{func}) A C expression to create an RTX representing the place where a function returns a value of data type @var{valtype}. @var{valtype} is a tree node representing a data type. Write @code{TYPE_MODE @@ -3728,7 +3875,7 @@ register where the return value is stored. The value can also be a @code{parallel} RTX, if the return value is in multiple places. See @code{FUNCTION_ARG} for an explanation of the @code{parallel} form. -If @code{PROMOTE_FUNCTION_RETURN} is defined, you must apply the same +If @code{TARGET_PROMOTE_FUNCTION_RETURN} returns true, you must apply the same promotion rules specified in @code{PROMOTE_MODE} if @var{valtype} is a scalar type. @@ -3740,10 +3887,10 @@ known. @code{FUNCTION_VALUE} is not used for return vales with aggregate data types, because these are returned in another way. See -@code{STRUCT_VALUE_REGNUM} and related macros, below. +@code{TARGET_STRUCT_VALUE_RTX} and related macros, below. +@end defmac -@findex FUNCTION_OUTGOING_VALUE -@item FUNCTION_OUTGOING_VALUE (@var{valtype}, @var{func}) +@defmac FUNCTION_OUTGOING_VALUE (@var{valtype}, @var{func}) Define this macro if the target machine has ``register windows'' so that the register in which a function returns its value is not the same as the one in which the caller sees the value. @@ -3758,10 +3905,10 @@ If @code{FUNCTION_OUTGOING_VALUE} is not defined, @code{FUNCTION_OUTGOING_VALUE} is not used for return vales with aggregate data types, because these are returned in another way. See -@code{STRUCT_VALUE_REGNUM} and related macros, below. +@code{TARGET_STRUCT_VALUE_RTX} and related macros, below. +@end defmac -@findex LIBCALL_VALUE -@item LIBCALL_VALUE (@var{mode}) +@defmac LIBCALL_VALUE (@var{mode}) A C expression to create an RTX representing the place where a library function returns a value of mode @var{mode}. If the precise function being called is known, @var{func} is a tree node @@ -3777,9 +3924,9 @@ compiled. The definition of @code{LIBRARY_VALUE} need not be concerned aggregate data types, because none of the library functions returns such types. +@end defmac -@findex FUNCTION_VALUE_REGNO_P -@item FUNCTION_VALUE_REGNO_P (@var{regno}) +@defmac FUNCTION_VALUE_REGNO_P (@var{regno}) A C expression that is nonzero if @var{regno} is the number of a hard register in which the values of called function may come back. @@ -3788,20 +3935,32 @@ second of a pair (for a value of type @code{double}, say) need not be recognized by this macro. So for most machines, this definition suffices: -@example +@smallexample #define FUNCTION_VALUE_REGNO_P(N) ((N) == 0) -@end example +@end smallexample If the machine has register windows, so that the caller and the called function use different registers for the return value, this macro should recognize only the caller's register numbers. +@end defmac -@findex APPLY_RESULT_SIZE -@item APPLY_RESULT_SIZE +@defmac APPLY_RESULT_SIZE Define this macro if @samp{untyped_call} and @samp{untyped_return} need more space than is implied by @code{FUNCTION_VALUE_REGNO_P} for saving and restoring an arbitrary return value. -@end table +@end defmac + +@deftypefn {Target Hook} bool TARGET_RETURN_IN_MSB (tree @var{type}) +This hook should return true if values of type @var{type} are returned +at the most significant end of a register (in other words, if they are +padded at the least significant end). You can assume that @var{type} +is returned in a register; the caller is required to check this. + +Note that the register provided by @code{FUNCTION_VALUE} must be able +to hold the complete return value. For example, if a 1-, 2- or 3-byte +structure is returned at the most significant end of a 4-byte register, +@code{FUNCTION_VALUE} should provide an @code{SImode} rtx. +@end deftypefn @node Aggregate Return @subsection How Large Values Are Returned @@ -3819,69 +3978,55 @@ is called the @dfn{structure value address}. This section describes how to control returning structure values in memory. -@table @code -@findex RETURN_IN_MEMORY -@item RETURN_IN_MEMORY (@var{type}) -A C expression which can inhibit the returning of certain function -values in registers, based on the type of value. A nonzero value says -to return the function value in memory, just as large structures are -always returned. Here @var{type} will be a C expression of type -@code{tree}, representing the data type of the value. +@deftypefn {Target Hook} bool TARGET_RETURN_IN_MEMORY (tree @var{type}, tree @var{fntype}) +This target hook should return a nonzero value to say to return the +function value in memory, just as large structures are always returned. +Here @var{type} will be the data type of the value, and @var{fntype} +will be the type of the function doing the returning, or @code{NULL} for +libcalls. Note that values of mode @code{BLKmode} must be explicitly handled -by this macro. Also, the option @option{-fpcc-struct-return} +by this function. Also, the option @option{-fpcc-struct-return} takes effect regardless of this macro. On most systems, it is -possible to leave the macro undefined; this causes a default +possible to leave the hook undefined; this causes a default definition to be used, whose value is the constant 1 for @code{BLKmode} values, and 0 otherwise. -Do not use this macro to indicate that structures and unions should always +Do not use this hook to indicate that structures and unions should always be returned in memory. You should instead use @code{DEFAULT_PCC_STRUCT_RETURN} to indicate this. +@end deftypefn -@findex DEFAULT_PCC_STRUCT_RETURN -@item DEFAULT_PCC_STRUCT_RETURN +@defmac DEFAULT_PCC_STRUCT_RETURN Define this macro to be 1 if all structure and union return values must be in memory. Since this results in slower code, this should be defined only if needed for compatibility with other compilers or with an ABI@. If you define this macro to be 0, then the conventions used for structure -and union return values are decided by the @code{RETURN_IN_MEMORY} macro. +and union return values are decided by the @code{TARGET_RETURN_IN_MEMORY} +target hook. If not defined, this defaults to the value 1. +@end defmac -@findex STRUCT_VALUE_REGNUM -@item STRUCT_VALUE_REGNUM -If the structure value address is passed in a register, then -@code{STRUCT_VALUE_REGNUM} should be the number of that register. - -@findex STRUCT_VALUE -@item STRUCT_VALUE -If the structure value address is not passed in a register, define -@code{STRUCT_VALUE} as an expression returning an RTX for the place -where the address is passed. If it returns 0, the address is passed as -an ``invisible'' first argument. +@deftypefn {Target Hook} rtx TARGET_STRUCT_VALUE_RTX (tree @var{fndecl}, int @var{incoming}) +This target hook should return the location of the structure value +address (normally a @code{mem} or @code{reg}), or 0 if the address is +passed as an ``invisible'' first argument. Note that @var{fndecl} may +be @code{NULL}, for libcalls. -@findex STRUCT_VALUE_INCOMING_REGNUM -@item STRUCT_VALUE_INCOMING_REGNUM On some architectures the place where the structure value address is found by the called function is not the same place that the caller put it. This can be due to register windows, or it could be because the function prologue moves it to a different place. +@var{incoming} is @code{true} when the location is needed in +the context of the called function, and @code{false} in the context of +the caller. -If the incoming location of the structure value address is in a -register, define this macro as the register number. - -@findex STRUCT_VALUE_INCOMING -@item STRUCT_VALUE_INCOMING -If the incoming location is not a register, then you should define -@code{STRUCT_VALUE_INCOMING} as an expression for an RTX for where the -called function should find the value. If it should find the value on -the stack, define this to create a @code{mem} which refers to the frame -pointer. A definition of 0 means that the address is passed as an -``invisible'' first argument. +If @var{incoming} is @code{true} and the address is to be found on the +stack, return a @code{mem} which refers to the frame pointer. +@end deftypefn -@findex PCC_STATIC_STRUCT_RETURN -@item PCC_STATIC_STRUCT_RETURN +@defmac PCC_STATIC_STRUCT_RETURN Define this macro if the usual system convention on the target machine for returning structures and unions is for the called function to return the address of a static variable containing the value. @@ -3891,7 +4036,7 @@ pass an address to the subroutine. This macro has effect in @option{-fpcc-struct-return} mode, but it does nothing when you use @option{-freg-struct-return} mode. -@end table +@end defmac @node Caller Saves @subsection Caller-Saves Register Allocation @@ -3900,17 +4045,7 @@ If you enable it, GCC can save registers around function calls. This makes it possible to use call-clobbered registers to hold variables that must live across calls. -@table @code -@findex DEFAULT_CALLER_SAVES -@item DEFAULT_CALLER_SAVES -Define this macro if function calls on the target machine do not preserve -any registers; in other words, if @code{CALL_USED_REGISTERS} has 1 -for all registers. When defined, this macro enables @option{-fcaller-saves} -by default for all optimization levels. It has no effect for optimization -levels 2 and higher, where @option{-fcaller-saves} is the default. - -@findex CALLER_SAVE_PROFITABLE -@item CALLER_SAVE_PROFITABLE (@var{refs}, @var{calls}) +@defmac CALLER_SAVE_PROFITABLE (@var{refs}, @var{calls}) A C expression to determine whether it is worthwhile to consider placing a pseudo-register in a call-clobbered hard register and saving and restoring it around each function call. The expression should be 1 when @@ -3918,15 +4053,15 @@ this is worth doing, and 0 otherwise. If you don't define this macro, a default is used which is good on most machines: @code{4 * @var{calls} < @var{refs}}. +@end defmac -@findex HARD_REGNO_CALLER_SAVE_MODE -@item HARD_REGNO_CALLER_SAVE_MODE (@var{regno}, @var{nregs}) +@defmac HARD_REGNO_CALLER_SAVE_MODE (@var{regno}, @var{nregs}) A C expression specifying which mode is required for saving @var{nregs} of a pseudo-register in call-clobbered hard register @var{regno}. If @var{regno} is unsuitable for caller save, @code{VOIDmode} should be returned. For most machines this macro need not be defined since GCC will select the smallest suitable mode. -@end table +@end defmac @node Function Entry @subsection Function Entry and Exit @@ -4044,8 +4179,6 @@ arguments that a function should pop. @xref{Scalar Return}. @c tell? --mew 5feb93 @end deftypefn -@table @code - @itemize @bullet @item @findex current_function_pretend_args_size @@ -4086,39 +4219,39 @@ Normally, it is necessary for the macros The C variable @code{current_function_is_leaf} is nonzero for such a function. -@findex EXIT_IGNORE_STACK -@item EXIT_IGNORE_STACK +@defmac EXIT_IGNORE_STACK Define this macro as a C expression that is nonzero if the return instruction or the function epilogue ignores the value of the stack pointer; in other words, if it is safe to delete an instruction to -adjust the stack pointer before a return from the function. +adjust the stack pointer before a return from the function. The +default is 0. Note that this macro's value is relevant only for functions for which frame pointers are maintained. It is never safe to delete a final stack adjustment in a function that has no frame pointer, and the compiler knows this regardless of @code{EXIT_IGNORE_STACK}. +@end defmac -@findex EPILOGUE_USES -@item EPILOGUE_USES (@var{regno}) +@defmac EPILOGUE_USES (@var{regno}) Define this macro as a C expression that is nonzero for registers that are used by the epilogue or the @samp{return} pattern. The stack and frame pointer registers are already be assumed to be used as needed. +@end defmac -@findex EH_USES -@item EH_USES (@var{regno}) +@defmac EH_USES (@var{regno}) Define this macro as a C expression that is nonzero for registers that are used by the exception handling mechanism, and so should be considered live on entry to an exception edge. +@end defmac -@findex DELAY_SLOTS_FOR_EPILOGUE -@item DELAY_SLOTS_FOR_EPILOGUE +@defmac DELAY_SLOTS_FOR_EPILOGUE Define this macro if the function epilogue contains delay slots to which instructions from the rest of the function can be ``moved''. The definition should be a C expression whose value is an integer representing the number of delay slots there. +@end defmac -@findex ELIGIBLE_FOR_EPILOGUE_DELAY -@item ELIGIBLE_FOR_EPILOGUE_DELAY (@var{insn}, @var{n}) +@defmac ELIGIBLE_FOR_EPILOGUE_DELAY (@var{insn}, @var{n}) A C expression that returns 1 if @var{insn} can be placed in delay slot number @var{n} of the epilogue. @@ -4143,10 +4276,8 @@ outputting the insns in this list, usually by calling You need not define this macro if you did not define @code{DELAY_SLOTS_FOR_EPILOGUE}. +@end defmac -@end table - -@findex TARGET_ASM_OUTPUT_MI_THUNK @deftypefn {Target Hook} void TARGET_ASM_OUTPUT_MI_THUNK (FILE *@var{file}, tree @var{thunk_fndecl}, HOST_WIDE_INT @var{delta}, tree @var{function}) A function that outputs the assembler code for a thunk function, used to implement C++ virtual function calls with multiple @@ -4181,21 +4312,19 @@ front end will generate a less efficient heavyweight thunk that calls not support varargs. @end deftypefn -@findex TARGET_ASM_OUTPUT_MI_VCALL_THUNK @deftypefn {Target Hook} void TARGET_ASM_OUTPUT_MI_VCALL_THUNK (FILE *@var{file}, tree @var{thunk_fndecl}, HOST_WIDE_INT @var{delta}, int @var{vcall_offset}, tree @var{function}) A function like @code{TARGET_ASM_OUTPUT_MI_THUNK}, except that if @var{vcall_offset} is nonzero, an additional adjustment should be made after adding @code{delta}. In particular, if @var{p} is the adjusted pointer, the following adjustment should be made: -@example +@smallexample p += (*((ptrdiff_t **)p))[vcall_offset/sizeof(ptrdiff_t)] -@end example +@end smallexample @noindent If this function is defined, it will always be used in place of @code{TARGET_ASM_OUTPUT_MI_THUNK}. - @end deftypefn @node Profiling @@ -4204,9 +4333,7 @@ If this function is defined, it will always be used in place of These macros will help you generate code for profiling. -@table @code -@findex FUNCTION_PROFILER -@item FUNCTION_PROFILER (@var{file}, @var{labelno}) +@defmac FUNCTION_PROFILER (@var{file}, @var{labelno}) A C statement or compound statement to output to @var{file} some assembler code to call the profiling subroutine @code{mcount}. @@ -4220,42 +4347,42 @@ Older implementations of @code{mcount} expect the address of a counter variable to be loaded into some register. The name of this variable is @samp{LP} followed by the number @var{labelno}, so you would generate the name using @samp{LP%d} in a @code{fprintf}. +@end defmac -@findex PROFILE_HOOK -@item PROFILE_HOOK +@defmac PROFILE_HOOK A C statement or compound statement to output to @var{file} some assembly code to call the profiling subroutine @code{mcount} even the target does not support profiling. +@end defmac -@findex NO_PROFILE_COUNTERS -@item NO_PROFILE_COUNTERS +@defmac NO_PROFILE_COUNTERS Define this macro if the @code{mcount} subroutine on your system does not need a counter variable allocated for each function. This is true for almost all modern implementations. If you define this macro, you must not use the @var{labelno} argument to @code{FUNCTION_PROFILER}. +@end defmac -@findex PROFILE_BEFORE_PROLOGUE -@item PROFILE_BEFORE_PROLOGUE +@defmac PROFILE_BEFORE_PROLOGUE Define this macro if the code for function profiling should come before the function prologue. Normally, the profiling code comes after. -@end table +@end defmac @node Tail Calls @subsection Permitting tail calls @cindex tail calls -@table @code -@findex FUNCTION_OK_FOR_SIBCALL -@item FUNCTION_OK_FOR_SIBCALL (@var{decl}) -A C expression that evaluates to true if it is ok to perform a sibling -call to @var{decl} from the current function. +@deftypefn {Target Hook} bool TARGET_FUNCTION_OK_FOR_SIBCALL (tree @var{decl}, tree @var{exp}) +True if it is ok to do sibling call optimization for the specified +call expression @var{exp}. @var{decl} will be the called function, +or @code{NULL} if this is an indirect call. It is not uncommon for limitations of calling conventions to prevent tail calls to functions outside the current unit of translation, or -during PIC compilation. Use this macro to enforce these restrictions, +during PIC compilation. The hook is used to enforce these restrictions, as the @code{sibcall} md pattern can not fail, or fall over to a -``normal'' call. -@end table +``normal'' call. The criteria for successful sibling call optimization +may vary greatly between different architectures. +@end deftypefn @node Varargs @section Implementing the Varargs Macros @@ -4278,9 +4405,7 @@ However, @code{va_start} should not use this argument. The way to find the end of the named arguments is with the built-in functions described below. -@table @code -@findex __builtin_saveregs -@item __builtin_saveregs () +@defmac __builtin_saveregs () Use this built-in function to save the argument registers in memory so that the varargs mechanism can access them. Both ISO and traditional versions of @code{va_start} must use @code{__builtin_saveregs}, unless @@ -4298,9 +4423,9 @@ This is because the registers must be saved before the function starts to use them for its own purposes. @c i rewrote the first sentence above to fix an overfull hbox. --mew @c 10feb93 +@end defmac -@findex __builtin_args_info -@item __builtin_args_info (@var{category}) +@defmac __builtin_args_info (@var{category}) Use this built-in function to find the first anonymous arguments in registers. @@ -4322,9 +4447,9 @@ of @code{va_start}, accessing each category just once and storing the value in the @code{va_list} object. This is because @code{va_list} will have to update the values, and there is no way to alter the values accessed by @code{__builtin_args_info}. +@end defmac -@findex __builtin_next_arg -@item __builtin_next_arg (@var{lastarg}) +@defmac __builtin_next_arg (@var{lastarg}) This is the equivalent of @code{__builtin_args_info}, for stack arguments. It returns the address of the first anonymous stack argument, as type @code{void *}. If @code{ARGS_GROW_DOWNWARD}, it @@ -4333,9 +4458,9 @@ argument. Use it in @code{va_start} to initialize the pointer for fetching arguments from the stack. Also use it in @code{va_start} to verify that the second parameter @var{lastarg} is the last named argument of the current function. +@end defmac -@findex __builtin_classify_type -@item __builtin_classify_type (@var{object}) +@defmac __builtin_classify_type (@var{object}) Since each machine has its own conventions for which data types are passed in which kind of register, your implementation of @code{va_arg} has to embody these conventions. The easiest way to categorize the @@ -4348,76 +4473,75 @@ kind of type that is---integer, floating, pointer, structure, and so on. The file @file{typeclass.h} defines an enumeration that you can use to interpret the values of @code{__builtin_classify_type}. -@end table +@end defmac These machine description macros help implement varargs: -@table @code -@findex EXPAND_BUILTIN_SAVEREGS -@item EXPAND_BUILTIN_SAVEREGS () -If defined, is a C expression that produces the machine-specific code -for a call to @code{__builtin_saveregs}. This code will be moved to the -very beginning of the function, before any parameter access are made. -The return value of this function should be an RTX that contains the -value to use as the return of @code{__builtin_saveregs}. - -@findex SETUP_INCOMING_VARARGS -@item SETUP_INCOMING_VARARGS (@var{args_so_far}, @var{mode}, @var{type}, @var{pretend_args_size}, @var{second_time}) -This macro offers an alternative to using @code{__builtin_saveregs} and -defining the macro @code{EXPAND_BUILTIN_SAVEREGS}. Use it to store the -anonymous register arguments into the stack so that all the arguments -appear to have been passed consecutively on the stack. Once this is -done, you can use the standard implementation of varargs that works for -machines that pass all their arguments on the stack. - -The argument @var{args_so_far} is the @code{CUMULATIVE_ARGS} data +@deftypefn {Target Hook} rtx TARGET_EXPAND_BUILTIN_SAVEREGS (void) +If defined, this hook produces the machine-specific code for a call to +@code{__builtin_saveregs}. This code will be moved to the very +beginning of the function, before any parameter access are made. The +return value of this function should be an RTX that contains the value +to use as the return of @code{__builtin_saveregs}. +@end deftypefn + +@deftypefn {Target Hook} void TARGET_SETUP_INCOMING_VARARGS (CUMULATIVE_ARGS *@var{args_so_far}, enum machine_mode @var{mode}, tree @var{type}, int *@var{pretend_args_size}, int @var{second_time}) +This target hook offers an alternative to using +@code{__builtin_saveregs} and defining the hook +@code{TARGET_EXPAND_BUILTIN_SAVEREGS}. Use it to store the anonymous +register arguments into the stack so that all the arguments appear to +have been passed consecutively on the stack. Once this is done, you can +use the standard implementation of varargs that works for machines that +pass all their arguments on the stack. + +The argument @var{args_so_far} points to the @code{CUMULATIVE_ARGS} data structure, containing the values that are obtained after processing the named arguments. The arguments @var{mode} and @var{type} describe the last named argument---its machine mode and its data type as a tree node. -The macro implementation should do two things: first, push onto the -stack all the argument registers @emph{not} used for the named -arguments, and second, store the size of the data thus pushed into the -@code{int}-valued variable whose name is supplied as the argument -@var{pretend_args_size}. The value that you store here will serve as -additional offset for setting up the stack frame. +The target hook should do two things: first, push onto the stack all the +argument registers @emph{not} used for the named arguments, and second, +store the size of the data thus pushed into the @code{int}-valued +variable pointed to by @var{pretend_args_size}. The value that you +store here will serve as additional offset for setting up the stack +frame. Because you must generate code to push the anonymous arguments at compile time without knowing their data types, -@code{SETUP_INCOMING_VARARGS} is only useful on machines that have just -a single category of argument register and use it uniformly for all data -types. +@code{TARGET_SETUP_INCOMING_VARARGS} is only useful on machines that +have just a single category of argument register and use it uniformly +for all data types. If the argument @var{second_time} is nonzero, it means that the arguments of the function are being analyzed for the second time. This happens for an inline function, which is not actually compiled until the -end of the source file. The macro @code{SETUP_INCOMING_VARARGS} should +end of the source file. The hook @code{TARGET_SETUP_INCOMING_VARARGS} should not generate any instructions in this case. +@end deftypefn -@findex STRICT_ARGUMENT_NAMING -@item STRICT_ARGUMENT_NAMING -Define this macro to be a nonzero value if the location where a function +@deftypefn {Target Hook} bool TARGET_STRICT_ARGUMENT_NAMING (CUMULATIVE_ARGS *@var{ca}) +Define this hook to return @code{true} if the location where a function argument is passed depends on whether or not it is a named argument. -This macro controls how the @var{named} argument to @code{FUNCTION_ARG} -is set for varargs and stdarg functions. If this macro returns a -nonzero value, the @var{named} argument is always true for named -arguments, and false for unnamed arguments. If it returns a value of -zero, but @code{SETUP_INCOMING_VARARGS} is defined, then all arguments -are treated as named. Otherwise, all named arguments except the last -are treated as named. +This hook controls how the @var{named} argument to @code{FUNCTION_ARG} +is set for varargs and stdarg functions. If this hook returns +@code{true}, the @var{named} argument is always true for named +arguments, and false for unnamed arguments. If it returns @code{false}, +but @code{TARGET_PRETEND_OUTOGOING_VARARGS_NAMED} returns @code{true}, +then all arguments are treated as named. Otherwise, all named arguments +except the last are treated as named. -You need not define this macro if it always returns zero. +You need not define this hook if it always returns zero. +@end deftypefn -@findex PRETEND_OUTGOING_VARARGS_NAMED -@item PRETEND_OUTGOING_VARARGS_NAMED +@deftypefn {Target Hook} bool TARGET_PRETEND_OUTGOING_VARARGS_NAMED If you need to conditionally change ABIs so that one works with -@code{SETUP_INCOMING_VARARGS}, but the other works like neither -@code{SETUP_INCOMING_VARARGS} nor @code{STRICT_ARGUMENT_NAMING} was -defined, then define this macro to return nonzero if -@code{SETUP_INCOMING_VARARGS} is used, zero otherwise. -Otherwise, you should not define this macro. -@end table +@code{TARGET_SETUP_INCOMING_VARARGS}, but the other works like neither +@code{TARGET_SETUP_INCOMING_VARARGS} nor @code{TARGET_STRICT_ARGUMENT_NAMING} was +defined, then define this hook to return @code{true} if +@code{SETUP_INCOMING_VARARGS} is used, @code{false} otherwise. +Otherwise, you should not define this hook. +@end deftypefn @node Trampolines @section Trampolines for Nested Functions @@ -4447,9 +4571,7 @@ proper offset from the start of the trampoline. On a RISC machine, it may be necessary to take out pieces of the address and store them separately. -@table @code -@findex TRAMPOLINE_TEMPLATE -@item TRAMPOLINE_TEMPLATE (@var{file}) +@defmac TRAMPOLINE_TEMPLATE (@var{file}) A C statement to output, on the stream @var{file}, assembler code for a block of data that contains the constant parts of a trampoline. This code should not include a label---the label is taken care of @@ -4459,35 +4581,35 @@ If you do not define this macro, it means no template is needed for the target. Do not define this macro on systems where the block move code to copy the trampoline into place would be larger than the code to generate it on the spot. +@end defmac -@findex TRAMPOLINE_SECTION -@item TRAMPOLINE_SECTION +@defmac TRAMPOLINE_SECTION The name of a subroutine to switch to the section in which the trampoline template is to be placed (@pxref{Sections}). The default is a value of @samp{readonly_data_section}, which places the trampoline in the section containing read-only data. +@end defmac -@findex TRAMPOLINE_SIZE -@item TRAMPOLINE_SIZE +@defmac TRAMPOLINE_SIZE A C expression for the size in bytes of the trampoline, as an integer. +@end defmac -@findex TRAMPOLINE_ALIGNMENT -@item TRAMPOLINE_ALIGNMENT +@defmac TRAMPOLINE_ALIGNMENT Alignment required for trampolines, in bits. If you don't define this macro, the value of @code{BIGGEST_ALIGNMENT} is used for aligning trampolines. +@end defmac -@findex INITIALIZE_TRAMPOLINE -@item INITIALIZE_TRAMPOLINE (@var{addr}, @var{fnaddr}, @var{static_chain}) +@defmac INITIALIZE_TRAMPOLINE (@var{addr}, @var{fnaddr}, @var{static_chain}) A C statement to initialize the variable parts of a trampoline. @var{addr} is an RTX for the address of the trampoline; @var{fnaddr} is an RTX for the address of the nested function; @var{static_chain} is an RTX for the static chain value that should be passed to the function when it is called. +@end defmac -@findex TRAMPOLINE_ADJUST_ADDRESS -@item TRAMPOLINE_ADJUST_ADDRESS (@var{addr}) +@defmac TRAMPOLINE_ADJUST_ADDRESS (@var{addr}) A C statement that should perform any machine-specific adjustment in the address of the trampoline. Its argument contains the address that was passed to @code{INITIALIZE_TRAMPOLINE}. In case the address to be @@ -4496,12 +4618,6 @@ the template was stored, the different address should be assigned to @var{addr}. If this macro is not defined, @var{addr} will be used for function calls. -@findex ALLOCATE_TRAMPOLINE -@item ALLOCATE_TRAMPOLINE (@var{fp}) -A C expression to allocate run-time space for a trampoline. The -expression value should be an RTX representing a memory reference to the -space for the trampoline. - @cindex @code{TARGET_ASM_FUNCTION_EPILOGUE} and trampolines @cindex @code{TARGET_ASM_FUNCTION_PROLOGUE} and trampolines If this macro is not defined, by default the trampoline is allocated as @@ -4513,12 +4629,11 @@ and @code{TARGET_ASM_FUNCTION_EPILOGUE}. @var{fp} points to a data structure, a @code{struct function}, which describes the compilation status of the immediate containing function of -the function which the trampoline is for. Normally (when -@code{ALLOCATE_TRAMPOLINE} is not defined), the stack slot for the +the function which the trampoline is for. The stack slot for the trampoline is in the stack frame of this containing function. Other allocation strategies probably must do something analogous with this information. -@end table +@end defmac Implementing trampolines is difficult on many machines because they have separate instruction and data caches. Writing into a stack location @@ -4532,40 +4647,27 @@ subroutine. The former technique makes trampoline execution faster; the latter makes initialization faster. To clear the instruction cache when a trampoline is initialized, define -the following macros which describe the shape of the cache. - -@table @code -@findex INSN_CACHE_SIZE -@item INSN_CACHE_SIZE -The total size in bytes of the cache. - -@findex INSN_CACHE_LINE_WIDTH -@item INSN_CACHE_LINE_WIDTH -The length in bytes of each cache line. The cache is divided into cache -lines which are disjoint slots, each holding a contiguous chunk of data -fetched from memory. Each time data is brought into the cache, an -entire line is read at once. The data loaded into a cache line is -always aligned on a boundary equal to the line size. - -@findex INSN_CACHE_DEPTH -@item INSN_CACHE_DEPTH -The number of alternative cache lines that can hold any particular memory -location. -@end table - -Alternatively, if the machine has system calls or instructions to clear -the instruction cache directly, you can define the following macro. - -@table @code -@findex CLEAR_INSN_CACHE -@item CLEAR_INSN_CACHE (@var{beg}, @var{end}) +the following macro. + +@defmac CLEAR_INSN_CACHE (@var{beg}, @var{end}) If defined, expands to a C expression clearing the @emph{instruction -cache} in the specified interval. If it is not defined, and the macro -@code{INSN_CACHE_SIZE} is defined, some generic code is generated to clear the -cache. The definition of this macro would typically be a series of -@code{asm} statements. Both @var{beg} and @var{end} are both pointer -expressions. -@end table +cache} in the specified interval. The definition of this macro would +typically be a series of @code{asm} statements. Both @var{beg} and +@var{end} are both pointer expressions. +@end defmac + +The operating system may also require the stack to be made executable +before calling the trampoline. To implement this requirement, define +the following macro. + +@defmac ENABLE_EXECUTE_STACK +Define this macro if certain operations must be performed before executing +code located on the stack. The macro should expand to a series of C +file-scope constructs (e.g. functions) and provide a unique entry point +named @code{__enable_execute_stack}. The target is responsible for +emitting calls to the entry point in the code, for example from the +@code{INITIALIZE_TRAMPOLINE} macro. +@end defmac To use a standard subroutine, define the following macro. In addition, you must make sure that the instructions in a trampoline fill an entire @@ -4573,9 +4675,7 @@ cache line with identical instructions, or else ensure that the beginning of the trampoline code is always aligned at the same point in its cache line. Look in @file{m68k.h} as a guide. -@table @code -@findex TRANSFER_FROM_TRAMPOLINE -@item TRANSFER_FROM_TRAMPOLINE +@defmac TRANSFER_FROM_TRAMPOLINE Define this macro if trampolines need a special subroutine to do their work. The macro should expand to a series of @code{asm} statements which will be compiled with GCC@. They go in a library function named @@ -4587,7 +4687,7 @@ special label of your own in the assembler code. Use one @code{asm} statement to generate an assembler label, and another to make the label global. Then trampolines can use that label to jump directly to your special assembler code. -@end table +@end defmac @node Library Calls @section Implicit Calls to Library Routines @@ -4597,102 +4697,59 @@ special assembler code. @c prevent bad page break with this line Here is an explanation of implicit calls to library routines. -@table @code -@findex MULSI3_LIBCALL -@item MULSI3_LIBCALL -A C string constant giving the name of the function to call for -multiplication of one signed full-word by another. If you do not -define this macro, the default name is used, which is @code{__mulsi3}, -a function defined in @file{libgcc.a}. - -@findex DIVSI3_LIBCALL -@item DIVSI3_LIBCALL -A C string constant giving the name of the function to call for -division of one signed full-word by another. If you do not define -this macro, the default name is used, which is @code{__divsi3}, a -function defined in @file{libgcc.a}. - -@findex UDIVSI3_LIBCALL -@item UDIVSI3_LIBCALL -A C string constant giving the name of the function to call for -division of one unsigned full-word by another. If you do not define -this macro, the default name is used, which is @code{__udivsi3}, a -function defined in @file{libgcc.a}. - -@findex MODSI3_LIBCALL -@item MODSI3_LIBCALL -A C string constant giving the name of the function to call for the -remainder in division of one signed full-word by another. If you do -not define this macro, the default name is used, which is -@code{__modsi3}, a function defined in @file{libgcc.a}. - -@findex UMODSI3_LIBCALL -@item UMODSI3_LIBCALL -A C string constant giving the name of the function to call for the -remainder in division of one unsigned full-word by another. If you do -not define this macro, the default name is used, which is -@code{__umodsi3}, a function defined in @file{libgcc.a}. - -@findex MULDI3_LIBCALL -@item MULDI3_LIBCALL -A C string constant giving the name of the function to call for -multiplication of one signed double-word by another. If you do not -define this macro, the default name is used, which is @code{__muldi3}, -a function defined in @file{libgcc.a}. - -@findex DIVDI3_LIBCALL -@item DIVDI3_LIBCALL -A C string constant giving the name of the function to call for -division of one signed double-word by another. If you do not define -this macro, the default name is used, which is @code{__divdi3}, a -function defined in @file{libgcc.a}. - -@findex UDIVDI3_LIBCALL -@item UDIVDI3_LIBCALL -A C string constant giving the name of the function to call for -division of one unsigned full-word by another. If you do not define -this macro, the default name is used, which is @code{__udivdi3}, a -function defined in @file{libgcc.a}. - -@findex MODDI3_LIBCALL -@item MODDI3_LIBCALL -A C string constant giving the name of the function to call for the -remainder in division of one signed double-word by another. If you do -not define this macro, the default name is used, which is -@code{__moddi3}, a function defined in @file{libgcc.a}. - -@findex UMODDI3_LIBCALL -@item UMODDI3_LIBCALL -A C string constant giving the name of the function to call for the -remainder in division of one unsigned full-word by another. If you do -not define this macro, the default name is used, which is -@code{__umoddi3}, a function defined in @file{libgcc.a}. - -@findex DECLARE_LIBRARY_RENAMES -@item DECLARE_LIBRARY_RENAMES +@defmac DECLARE_LIBRARY_RENAMES This macro, if defined, should expand to a piece of C code that will get expanded when compiling functions for libgcc.a. It can be used to -provide alternate names for gcc's internal library functions if there +provide alternate names for GCC's internal library functions if there are ABI-mandated names that the compiler should provide. +@end defmac + +@findex init_one_libfunc +@findex set_optab_libfunc +@deftypefn {Target Hook} void TARGET_INIT_LIBFUNCS (void) +This hook should declare additional library routines or rename +existing ones, using the functions @code{set_optab_libfunc} and +@code{init_one_libfunc} defined in @file{optabs.c}. +@code{init_optabs} calls this macro after initializing all the normal +library routines. -@findex INIT_TARGET_OPTABS -@item INIT_TARGET_OPTABS -Define this macro as a C statement that declares additional library -routines renames existing ones. @code{init_optabs} calls this macro after -initializing all the normal library routines. +The default is to do nothing. Most ports don't need to define this hook. +@end deftypefn -@findex FLOAT_LIB_COMPARE_RETURNS_BOOL (@var{mode}, @var{comparison}) -@item FLOAT_LIB_COMPARE_RETURNS_BOOL -Define this macro as a C statement that returns nonzero if a call to -the floating point comparison library function will return a boolean -value that indicates the result of the comparison. It should return -zero if one of gcc's own libgcc functions is called. +@defmac TARGET_FLOAT_LIB_COMPARE_RETURNS_BOOL (@var{mode}, @var{comparison}) +This macro should return @code{true} if the library routine that +implements the floating point comparison operator @var{comparison} in +mode @var{mode} will return a boolean, and @var{false} if it will +return a tristate. -Most ports don't need to define this macro. +GCC's own floating point libraries return tristates from the +comparison operators, so the default returns false always. Most ports +don't need to define this macro. +@end defmac + +@cindex US Software GOFAST, floating point emulation library +@cindex floating point emulation library, US Software GOFAST +@cindex GOFAST, floating point emulation library +@findex gofast_maybe_init_libfuncs +@defmac US_SOFTWARE_GOFAST +Define this macro if your system C library uses the US Software GOFAST +library to provide floating point emulation. + +In addition to defining this macro, your architecture must set +@code{TARGET_INIT_LIBFUNCS} to @code{gofast_maybe_init_libfuncs}, or +else call that function from its version of that hook. It is defined +in @file{config/gofast.h}, which must be included by your +architecture's @file{@var{cpu}.c} file. See @file{sparc/sparc.c} for +an example. + +If this macro is defined, the +@code{TARGET_FLOAT_LIB_COMPARE_RETURNS_BOOL} target hook must return +false for @code{SFmode} and @code{DFmode} comparisons. +@end defmac -@findex TARGET_EDOM @cindex @code{EDOM}, implicit usage -@item TARGET_EDOM +@findex matherr +@defmac TARGET_EDOM The value of @code{EDOM} on the target machine, as a C integer constant expression. If you don't define this macro, GCC does not attempt to deposit the value of @code{EDOM} into @code{errno} directly. Look in @@ -4704,37 +4761,37 @@ domain errors by calling the library function and letting it report the error. If mathematical functions on your system use @code{matherr} when there is an error, then you should leave @code{TARGET_EDOM} undefined so that @code{matherr} is used normally. +@end defmac -@findex GEN_ERRNO_RTX @cindex @code{errno}, implicit usage -@item GEN_ERRNO_RTX +@defmac GEN_ERRNO_RTX Define this macro as a C expression to create an rtl expression that refers to the global ``variable'' @code{errno}. (On certain systems, @code{errno} may not actually be a variable.) If you don't define this macro, a reasonable default is used. +@end defmac -@findex TARGET_MEM_FUNCTIONS @cindex @code{bcopy}, implicit usage @cindex @code{memcpy}, implicit usage @cindex @code{memmove}, implicit usage @cindex @code{bzero}, implicit usage @cindex @code{memset}, implicit usage -@item TARGET_MEM_FUNCTIONS +@defmac TARGET_MEM_FUNCTIONS Define this macro if GCC should generate calls to the ISO C (and System V) library functions @code{memcpy}, @code{memmove} and @code{memset} rather than the BSD functions @code{bcopy} and @code{bzero}. +@end defmac + +@cindex C99 math functions, implicit usage +@defmac TARGET_C99_FUNCTIONS +When this macro is nonzero, GCC will implicitly optimize @code{sin} calls into +@code{sinf} and similarly for other functions defined by C99 standard. The +default is nonzero that should be proper value for most modern systems, however +number of existing systems lacks support for these functions in the runtime so +they needs this macro to be redefined to 0. +@end defmac -@findex LIBGCC_NEEDS_DOUBLE -@item LIBGCC_NEEDS_DOUBLE -Define this macro if @code{float} arguments cannot be passed to library -routines (so they must be converted to @code{double}). This macro -affects both how library calls are generated and how the library -routines in @file{libgcc.a} accept their arguments. It is useful on -machines where floating and fixed point arguments are passed -differently, such as the i860. - -@findex NEXT_OBJC_RUNTIME -@item NEXT_OBJC_RUNTIME +@defmac NEXT_OBJC_RUNTIME Define this macro to generate code for Objective-C message sending using the calling convention of the NeXT system. This calling convention involves passing the object, the selector and the method arguments all @@ -4742,7 +4799,7 @@ at once to the method-lookup library function. The default calling convention passes just the object and the selector to the lookup function, which returns a pointer to the method. -@end table +@end defmac @node Addressing Modes @section Addressing Modes @@ -4751,55 +4808,50 @@ to the lookup function, which returns a pointer to the method. @c prevent bad page break with this line This is about addressing modes. -@table @code -@findex HAVE_PRE_INCREMENT -@findex HAVE_PRE_DECREMENT -@findex HAVE_POST_INCREMENT -@findex HAVE_POST_DECREMENT -@item HAVE_PRE_INCREMENT -@itemx HAVE_PRE_DECREMENT -@itemx HAVE_POST_INCREMENT -@itemx HAVE_POST_DECREMENT +@defmac HAVE_PRE_INCREMENT +@defmacx HAVE_PRE_DECREMENT +@defmacx HAVE_POST_INCREMENT +@defmacx HAVE_POST_DECREMENT A C expression that is nonzero if the machine supports pre-increment, pre-decrement, post-increment, or post-decrement addressing respectively. +@end defmac -@findex HAVE_POST_MODIFY_DISP -@findex HAVE_PRE_MODIFY_DISP -@item HAVE_PRE_MODIFY_DISP -@itemx HAVE_POST_MODIFY_DISP +@defmac HAVE_PRE_MODIFY_DISP +@defmacx HAVE_POST_MODIFY_DISP A C expression that is nonzero if the machine supports pre- or post-address side-effect generation involving constants other than the size of the memory operand. +@end defmac -@findex HAVE_POST_MODIFY_REG -@findex HAVE_PRE_MODIFY_REG -@item HAVE_PRE_MODIFY_REG -@itemx HAVE_POST_MODIFY_REG +@defmac HAVE_PRE_MODIFY_REG +@defmacx HAVE_POST_MODIFY_REG A C expression that is nonzero if the machine supports pre- or post-address side-effect generation involving a register displacement. +@end defmac -@findex CONSTANT_ADDRESS_P -@item CONSTANT_ADDRESS_P (@var{x}) +@defmac CONSTANT_ADDRESS_P (@var{x}) A C expression that is 1 if the RTX @var{x} is a constant which is a valid address. On most machines, this can be defined as @code{CONSTANT_P (@var{x})}, but a few machines are more restrictive in which constant addresses are supported. +@end defmac -@findex CONSTANT_P -@code{CONSTANT_P} accepts integer-values expressions whose values are -not explicitly known, such as @code{symbol_ref}, @code{label_ref}, and -@code{high} expressions and @code{const} arithmetic expressions, in -addition to @code{const_int} and @code{const_double} expressions. +@defmac CONSTANT_P (@var{x}) +@code{CONSTANT_P}, which is defined by target-independent code, +accepts integer-values expressions whose values are not explicitly +known, such as @code{symbol_ref}, @code{label_ref}, and @code{high} +expressions and @code{const} arithmetic expressions, in addition to +@code{const_int} and @code{const_double} expressions. +@end defmac -@findex MAX_REGS_PER_ADDRESS -@item MAX_REGS_PER_ADDRESS +@defmac MAX_REGS_PER_ADDRESS A number, the maximum number of registers that can appear in a valid memory address. Note that it is up to you to specify a value equal to the maximum number that @code{GO_IF_LEGITIMATE_ADDRESS} would ever accept. +@end defmac -@findex GO_IF_LEGITIMATE_ADDRESS -@item GO_IF_LEGITIMATE_ADDRESS (@var{mode}, @var{x}, @var{label}) +@defmac GO_IF_LEGITIMATE_ADDRESS (@var{mode}, @var{x}, @var{label}) A C compound statement with a conditional @code{goto @var{label};} executed if @var{x} (an RTX) is a legitimate memory address on the target machine for a memory operand of mode @var{mode}. @@ -4851,21 +4903,9 @@ into the @code{symbol_ref}, and then check for it here. When you see a @code{const}, you will have to look inside it to find the @code{symbol_ref} in order to determine the section. @xref{Assembler Format}. +@end defmac -@findex saveable_obstack -The best way to modify the name string is by adding text to the -beginning, with suitable punctuation to prevent any ambiguity. Allocate -the new name in @code{saveable_obstack}. You will have to modify -@code{ASM_OUTPUT_LABELREF} to remove and decode the added text and -output the name accordingly, and define @code{TARGET_STRIP_NAME_ENCODING} -to access the original name string. - -You can check the information stored here into the @code{symbol_ref} in -the definitions of the macros @code{GO_IF_LEGITIMATE_ADDRESS} and -@code{PRINT_OPERAND_ADDRESS}. - -@findex REG_OK_FOR_BASE_P -@item REG_OK_FOR_BASE_P (@var{x}) +@defmac REG_OK_FOR_BASE_P (@var{x}) A C expression that is nonzero if @var{x} (assumed to be a @code{reg} RTX) is valid for use as a base register. For hard registers, it should always accept those which the hardware permits and reject the @@ -4873,18 +4913,18 @@ others. Whether the macro accepts or rejects pseudo registers must be controlled by @code{REG_OK_STRICT} as described above. This usually requires two variant definitions, of which @code{REG_OK_STRICT} controls the one actually used. +@end defmac -@findex REG_MODE_OK_FOR_BASE_P -@item REG_MODE_OK_FOR_BASE_P (@var{x}, @var{mode}) +@defmac REG_MODE_OK_FOR_BASE_P (@var{x}, @var{mode}) A C expression that is just like @code{REG_OK_FOR_BASE_P}, except that that expression may examine the mode of the memory reference in @var{mode}. You should define this macro if the mode of the memory reference affects whether a register may be used as a base register. If you define this macro, the compiler will use it instead of @code{REG_OK_FOR_BASE_P}. +@end defmac -@findex REG_OK_FOR_INDEX_P -@item REG_OK_FOR_INDEX_P (@var{x}) +@defmac REG_OK_FOR_INDEX_P (@var{x}) A C expression that is nonzero if @var{x} (assumed to be a @code{reg} RTX) is valid for use as an index register. @@ -4896,9 +4936,9 @@ labeling is used must fit the machine's constraints of which registers may serve in each capacity. The compiler will try both labelings, looking for one that is valid, and will reload one or both registers only if neither labeling works. +@end defmac -@findex FIND_BASE_TERM -@item FIND_BASE_TERM (@var{x}) +@defmac FIND_BASE_TERM (@var{x}) A C expression to determine the base term of address @var{x}. This macro is used in only one place: `find_base_term' in alias.c. @@ -4907,16 +4947,16 @@ that alias analysis can understand machine-dependent addresses. The typical use of this macro is to handle addresses containing a label_ref or symbol_ref within an UNSPEC@. +@end defmac -@findex LEGITIMIZE_ADDRESS -@item LEGITIMIZE_ADDRESS (@var{x}, @var{oldx}, @var{mode}, @var{win}) +@defmac LEGITIMIZE_ADDRESS (@var{x}, @var{oldx}, @var{mode}, @var{win}) A C compound statement that attempts to replace @var{x} with a valid memory address for an operand of mode @var{mode}. @var{win} will be a C statement label elsewhere in the code; the macro definition may use -@example +@smallexample GO_IF_LEGITIMATE_ADDRESS (@var{mode}, @var{x}, @var{win}); -@end example +@end smallexample @noindent to avoid further processing if the address has become legitimate. @@ -4934,9 +4974,9 @@ It is not necessary for this macro to come up with a legitimate address. The compiler has standard ways of doing so in all cases. In fact, it is safe for this macro to do nothing. But often a machine-dependent strategy can generate better code. +@end defmac -@findex LEGITIMIZE_RELOAD_ADDRESS -@item LEGITIMIZE_RELOAD_ADDRESS (@var{x}, @var{mode}, @var{opnum}, @var{type}, @var{ind_levels}, @var{win}) +@defmac LEGITIMIZE_RELOAD_ADDRESS (@var{x}, @var{mode}, @var{opnum}, @var{type}, @var{ind_levels}, @var{win}) A C compound statement that attempts to replace @var{x}, which is an address that needs reloading, with a valid memory address for an operand of mode @var{mode}. @var{win} will be a C statement label elsewhere in the code. @@ -4983,9 +5023,9 @@ single level of rtl. Thus, if the part to be changed is not at the top level, you'll need to replace first the top level. It is not necessary for this macro to come up with a legitimate address; but often a machine-dependent strategy can generate better code. +@end defmac -@findex GO_IF_MODE_DEPENDENT_ADDRESS -@item GO_IF_MODE_DEPENDENT_ADDRESS (@var{addr}, @var{label}) +@defmac GO_IF_MODE_DEPENDENT_ADDRESS (@var{addr}, @var{label}) A C statement or compound statement with a conditional @code{goto @var{label};} executed if memory address @var{x} (an RTX) can have different meanings depending on the machine mode of the memory @@ -4998,15 +5038,15 @@ of the operand being addressed. Some machines have other mode-dependent addresses. Many RISC machines have no mode-dependent addresses. You may assume that @var{addr} is a valid address for the machine. +@end defmac -@findex LEGITIMATE_CONSTANT_P -@item LEGITIMATE_CONSTANT_P (@var{x}) +@defmac LEGITIMATE_CONSTANT_P (@var{x}) A C expression that is nonzero if @var{x} is a legitimate constant for an immediate operand on the target machine. You can assume that @var{x} satisfies @code{CONSTANT_P}, so you need not check this. In fact, @samp{1} is a suitable definition for this macro on machines where anything @code{CONSTANT_P} is valid. -@end table +@end defmac @node Condition Code @section Condition Code Status @@ -5026,25 +5066,23 @@ Sometimes additional machine-specific flags must be defined in the machine description header file. It can also add additional machine-specific information by defining @code{CC_STATUS_MDEP}. -@table @code -@findex CC_STATUS_MDEP -@item CC_STATUS_MDEP +@defmac CC_STATUS_MDEP C code for a data type which is used for declaring the @code{mdep} component of @code{cc_status}. It defaults to @code{int}. This macro is not used on machines that do not use @code{cc0}. +@end defmac -@findex CC_STATUS_MDEP_INIT -@item CC_STATUS_MDEP_INIT +@defmac CC_STATUS_MDEP_INIT A C expression to initialize the @code{mdep} field to ``empty''. The default definition does nothing, since most machines don't use the field anyway. If you want to use the field, you should probably define this macro to initialize it. This macro is not used on machines that do not use @code{cc0}. +@end defmac -@findex NOTICE_UPDATE_CC -@item NOTICE_UPDATE_CC (@var{exp}, @var{insn}) +@defmac NOTICE_UPDATE_CC (@var{exp}, @var{insn}) A C compound statement to set the components of @code{cc_status} appropriately for an insn @var{insn} whose body is @var{exp}. It is this macro's responsibility to recognize insns that set the condition @@ -5079,34 +5117,9 @@ A possible definition of @code{NOTICE_UPDATE_CC} is to call a function that looks at an attribute (@pxref{Insn Attributes}) named, for example, @samp{cc}. This avoids having detailed information about patterns in two places, the @file{md} file and in @code{NOTICE_UPDATE_CC}. +@end defmac -@findex EXTRA_CC_MODES -@item EXTRA_CC_MODES -Condition codes are represented in registers by machine modes of class -@code{MODE_CC}. By default, there is just one mode, @code{CCmode}, with -this class. If you need more such modes, create a file named -@file{@var{machine}-modes.def} in your @file{config/@var{machine}} -directory (@pxref{Back End, , Anatomy of a Target Back End}), containing -a list of these modes. Each entry in the list should be a call to the -macro @code{CC}. This macro takes one argument, which is the name of -the mode: it should begin with @samp{CC}. Do not put quotation marks -around the name, or include the trailing @samp{mode}; these are -automatically added. There should not be anything else in the file -except comments. - -A sample @file{@var{machine}-modes.def} file might look like this: - -@smallexample -CC (CC_NOOV) /* @r{Comparison only valid if there was no overflow.} */ -CC (CCFP) /* @r{Floating point comparison that cannot trap.} */ -CC (CCFPE) /* @r{Floating point comparison that may trap.} */ -@end smallexample - -When you create this file, the macro @code{EXTRA_CC_MODES} is -automatically defined by @command{configure}, with value @samp{1}. - -@findex SELECT_CC_MODE -@item SELECT_CC_MODE (@var{op}, @var{x}, @var{y}) +@defmac SELECT_CC_MODE (@var{op}, @var{x}, @var{y}) Returns a mode from class @code{MODE_CC} to be used when comparison operation code @var{op} is applied to rtx @var{x} and @var{y}. For example, on the SPARC, @code{SELECT_CC_MODE} is defined as (see @@ -5122,10 +5135,11 @@ definition) ? CC_NOOVmode : CCmode)) @end smallexample -You need not define this macro if @code{EXTRA_CC_MODES} is not defined. +You should define this macro if and only if you define extra CC modes +in @file{@var{machine}-modes.def}. +@end defmac -@findex CANONICALIZE_COMPARISON -@item CANONICALIZE_COMPARISON (@var{code}, @var{op0}, @var{op1}) +@defmac CANONICALIZE_COMPARISON (@var{code}, @var{op0}, @var{op1}) On some machines not all possible comparisons are defined, but you can convert an invalid comparison into a valid one. For example, the Alpha does not have a @code{GT} comparison, but you can use an @code{LT} @@ -5143,9 +5157,9 @@ valid but will see if the resulting insn matches a pattern in the You need not define this macro if it would never change the comparison code or operands. +@end defmac -@findex REVERSIBLE_CC_MODE -@item REVERSIBLE_CC_MODE (@var{mode}) +@defmac REVERSIBLE_CC_MODE (@var{mode}) A C expression whose value is one if it is always safe to reverse a comparison whose mode is @var{mode}. If @code{SELECT_CC_MODE} can ever return @var{mode} for a floating-point inequality comparison, @@ -5159,8 +5173,9 @@ inequality comparisons are always given @code{CCFPEmode}: @smallexample #define REVERSIBLE_CC_MODE(MODE) ((MODE) != CCFPEmode) @end smallexample +@end defmac -@findex REVERSE_CONDITION (@var{code}, @var{mode}) +@defmac REVERSE_CONDITION (@var{code}, @var{mode}) A C expression whose value is reversed condition code of the @var{code} for comparison done in CC_MODE @var{mode}. The macro is used only in case @code{REVERSIBLE_CC_MODE (@var{mode})} is nonzero. Define this macro in case @@ -5174,9 +5189,9 @@ like: ((MODE) != CCFPmode ? reverse_condition (CODE) \ : reverse_condition_maybe_unordered (CODE)) @end smallexample +@end defmac -@findex REVERSE_CONDEXEC_PREDICATES_P -@item REVERSE_CONDEXEC_PREDICATES_P (@var{code1}, @var{code2}) +@defmac REVERSE_CONDEXEC_PREDICATES_P (@var{code1}, @var{code2}) A C expression that returns true if the conditional execution predicate @var{code1} is the inverse of @var{code2} and vice versa. Define this to return 0 if the target has conditional execution predicates that cannot be @@ -5187,8 +5202,35 @@ follows: #define REVERSE_CONDEXEC_PREDICATES_P (x, y) \ ((x) == reverse_condition (y)) @end smallexample +@end defmac -@end table +@deftypefn {Target Hook} bool TARGET_FIXED_CONDITION_CODE_REGS (unsigned int *, unsigned int *) +On targets which do not use @code{(cc0)}, and which use a hard +register rather than a pseudo-register to hold condition codes, the +regular CSE passes are often not able to identify cases in which the +hard register is set to a common value. Use this hook to enable a +small pass which optimizes such cases. This hook should return true +to enable this pass, and it should set the integers to which its +arguments point to the hard register numbers used for condition codes. +When there is only one such register, as is true on most systems, the +integer pointed to by the second argument should be set to +@code{INVALID_REGNUM}. + +The default version of this hook returns false. +@end deftypefn + +@deftypefn {Target Hook} enum machine_mode TARGET_CC_MODES_COMPATIBLE (enum machine_mode, enum machine_mode) +On targets which use multiple condition code modes in class +@code{MODE_CC}, it is sometimes the case that a comparison can be +validly done in more than one mode. On such a system, define this +target hook to take two mode arguments and to return a mode in which +both comparisons may be validly done. If there is no such mode, +return @code{VOIDmode}. + +The default version of this hook checks whether the modes are the +same. If they are, it returns that mode. If they are different, it +returns @code{VOIDmode}. +@end deftypefn @node Costs @section Describing Relative Costs of Operations @@ -5199,94 +5241,7 @@ follows: These macros let you describe the relative speed of various operations on the target machine. -@table @code -@findex CONST_COSTS -@item CONST_COSTS (@var{x}, @var{code}, @var{outer_code}) -A part of a C @code{switch} statement that describes the relative costs -of constant RTL expressions. It must contain @code{case} labels for -expression codes @code{const_int}, @code{const}, @code{symbol_ref}, -@code{label_ref} and @code{const_double}. Each case must ultimately -reach a @code{return} statement to return the relative cost of the use -of that kind of constant value in an expression. The cost may depend on -the precise value of the constant, which is available for examination in -@var{x}, and the rtx code of the expression in which it is contained, -found in @var{outer_code}. - -@var{code} is the expression code---redundant, since it can be -obtained with @code{GET_CODE (@var{x})}. - -@findex RTX_COSTS -@findex COSTS_N_INSNS -@item RTX_COSTS (@var{x}, @var{code}, @var{outer_code}) -Like @code{CONST_COSTS} but applies to nonconstant RTL expressions. -This can be used, for example, to indicate how costly a multiply -instruction is. In writing this macro, you can use the construct -@code{COSTS_N_INSNS (@var{n})} to specify a cost equal to @var{n} fast -instructions. @var{outer_code} is the code of the expression in which -@var{x} is contained. - -This macro is optional; do not define it if the default cost assumptions -are adequate for the target machine. - -@findex DEFAULT_RTX_COSTS -@item DEFAULT_RTX_COSTS (@var{x}, @var{code}, @var{outer_code}) -This macro, if defined, is called for any case not handled by the -@code{RTX_COSTS} or @code{CONST_COSTS} macros. This eliminates the need -to put case labels into the macro, but the code, or any functions it -calls, must assume that the RTL in @var{x} could be of any type that has -not already been handled. The arguments are the same as for -@code{RTX_COSTS}, and the macro should execute a return statement giving -the cost of any RTL expressions that it can handle. The default cost -calculation is used for any RTL for which this macro does not return a -value. - -This macro is optional; do not define it if the default cost assumptions -are adequate for the target machine. - -@findex ADDRESS_COST -@item ADDRESS_COST (@var{address}) -An expression giving the cost of an addressing mode that contains -@var{address}. If not defined, the cost is computed from -the @var{address} expression and the @code{CONST_COSTS} values. - -For most CISC machines, the default cost is a good approximation of the -true cost of the addressing mode. However, on RISC machines, all -instructions normally have the same length and execution time. Hence -all addresses will have equal costs. - -In cases where more than one form of an address is known, the form with -the lowest cost will be used. If multiple forms have the same, lowest, -cost, the one that is the most complex will be used. - -For example, suppose an address that is equal to the sum of a register -and a constant is used twice in the same basic block. When this macro -is not defined, the address will be computed in a register and memory -references will be indirect through that register. On machines where -the cost of the addressing mode containing the sum is no higher than -that of a simple indirect reference, this will produce an additional -instruction and possibly require an additional register. Proper -specification of this macro eliminates this overhead for such machines. - -Similar use of this macro is made in strength reduction of loops. - -@var{address} need not be valid as an address. In such a case, the cost -is not relevant and can be any value; invalid addresses need not be -assigned a different cost. - -On machines where an address involving more than one register is as -cheap as an address computation involving only one register, defining -@code{ADDRESS_COST} to reflect this can cause two registers to be live -over a region of code where only one would have been if -@code{ADDRESS_COST} were not defined in that manner. This effect should -be considered in the definition of this macro. Equivalent costs should -probably only be given to addresses with different numbers of registers -on machines with lots of registers. - -This macro will normally either not be defined or be defined as a -constant. - -@findex REGISTER_MOVE_COST -@item REGISTER_MOVE_COST (@var{mode}, @var{from}, @var{to}) +@defmac REGISTER_MOVE_COST (@var{mode}, @var{from}, @var{to}) A C expression for the cost of moving data of mode @var{mode} from a register in class @var{from} to one in class @var{to}. The classes are expressed using the enumeration values such as @code{GENERAL_REGS}. A @@ -5303,9 +5258,9 @@ classes returns a value of 2, reload does not check to ensure that the constraints of the insn are met. Setting a cost of other than 2 will allow reload to verify that the constraints are met. You should do this if the @samp{mov@var{m}} pattern's constraints do not allow such copying. +@end defmac -@findex MEMORY_MOVE_COST -@item MEMORY_MOVE_COST (@var{mode}, @var{class}, @var{in}) +@defmac MEMORY_MOVE_COST (@var{mode}, @var{class}, @var{in}) A C expression for the cost of moving data of mode @var{mode} between a register of class @var{class} and memory; @var{in} is zero if the value is to be written to memory, nonzero if it is to be read in. This cost @@ -5327,20 +5282,18 @@ secondary register in the conventional way but the default base value of 4 is not correct for your machine, define this macro to add some other value to the result of that function. The arguments to that function are the same as to this macro. +@end defmac -@findex BRANCH_COST -@item BRANCH_COST +@defmac BRANCH_COST A C expression for the cost of a branch instruction. A value of 1 is the default; other values are interpreted relative to that. -@end table +@end defmac Here are additional macros which do not specify precise relative costs, but only that certain actions are more expensive than GCC would ordinarily expect. -@table @code -@findex SLOW_BYTE_ACCESS -@item SLOW_BYTE_ACCESS +@defmac SLOW_BYTE_ACCESS Define this macro as a C expression which is nonzero if accessing less than a word of memory (i.e.@: a @code{char} or a @code{short}) is no faster than accessing a word of memory, i.e., if such access @@ -5353,9 +5306,9 @@ load will be used if alignment permits. Unless bytes accesses are faster than word accesses, using word accesses is preferable since it may eliminate subsequent memory access if subsequent accesses occur to other fields in the same word of the structure, but to different bytes. +@end defmac -@findex SLOW_UNALIGNED_ACCESS -@item SLOW_UNALIGNED_ACCESS (@var{mode}, @var{alignment}) +@defmac SLOW_UNALIGNED_ACCESS (@var{mode}, @var{alignment}) Define this macro to be the value 1 if memory accesses described by the @var{mode} and @var{alignment} parameters have a cost many times greater than aligned accesses, for example if they are emulated in a trap @@ -5370,15 +5323,9 @@ cycle or two to the time for a memory access. If the value of this macro is always zero, it need not be defined. If this macro is defined, it should produce a nonzero value when @code{STRICT_ALIGNMENT} is nonzero. +@end defmac -@findex DONT_REDUCE_ADDR -@item DONT_REDUCE_ADDR -Define this macro to inhibit strength reduction of memory addresses. -(On some machines, such strength reduction seems to do harm rather -than good.) - -@findex MOVE_RATIO -@item MOVE_RATIO +@defmac MOVE_RATIO The threshold of number of scalar memory-to-memory move insns, @emph{below} which a sequence of insns should be generated instead of a string move insn or a library call. Increasing the value will always @@ -5389,94 +5336,165 @@ Note that on machines where the corresponding move insn is a the number of such sequences. If you don't define this, a reasonable default is used. +@end defmac -@findex MOVE_BY_PIECES_P -@item MOVE_BY_PIECES_P (@var{size}, @var{alignment}) +@defmac MOVE_BY_PIECES_P (@var{size}, @var{alignment}) A C expression used to determine whether @code{move_by_pieces} will be used to copy a chunk of memory, or whether some other block move mechanism will be used. Defaults to 1 if @code{move_by_pieces_ninsns} returns less than @code{MOVE_RATIO}. +@end defmac -@findex MOVE_MAX_PIECES -@item MOVE_MAX_PIECES +@defmac MOVE_MAX_PIECES A C expression used by @code{move_by_pieces} to determine the largest unit a load or store used to copy memory is. Defaults to @code{MOVE_MAX}. +@end defmac -@findex CLEAR_RATIO -@item CLEAR_RATIO +@defmac CLEAR_RATIO The threshold of number of scalar move insns, @emph{below} which a sequence of insns should be generated to clear memory instead of a string clear insn or a library call. Increasing the value will always make code faster, but eventually incurs high cost in increased code size. If you don't define this, a reasonable default is used. +@end defmac -@findex CLEAR_BY_PIECES_P -@item CLEAR_BY_PIECES_P (@var{size}, @var{alignment}) +@defmac CLEAR_BY_PIECES_P (@var{size}, @var{alignment}) A C expression used to determine whether @code{clear_by_pieces} will be used to clear a chunk of memory, or whether some other block clear mechanism will be used. Defaults to 1 if @code{move_by_pieces_ninsns} returns less than @code{CLEAR_RATIO}. +@end defmac + +@defmac STORE_BY_PIECES_P (@var{size}, @var{alignment}) +A C expression used to determine whether @code{store_by_pieces} will be +used to set a chunk of memory to a constant value, or whether some other +mechanism will be used. Used by @code{__builtin_memset} when storing +values other than constant zero and by @code{__builtin_strcpy} when +when called with a constant source string. +Defaults to @code{MOVE_BY_PIECES_P}. +@end defmac -@findex USE_LOAD_POST_INCREMENT -@item USE_LOAD_POST_INCREMENT (@var{mode}) +@defmac USE_LOAD_POST_INCREMENT (@var{mode}) A C expression used to determine whether a load postincrement is a good thing to use for a given mode. Defaults to the value of @code{HAVE_POST_INCREMENT}. +@end defmac -@findex USE_LOAD_POST_DECREMENT -@item USE_LOAD_POST_DECREMENT (@var{mode}) +@defmac USE_LOAD_POST_DECREMENT (@var{mode}) A C expression used to determine whether a load postdecrement is a good thing to use for a given mode. Defaults to the value of @code{HAVE_POST_DECREMENT}. +@end defmac -@findex USE_LOAD_PRE_INCREMENT -@item USE_LOAD_PRE_INCREMENT (@var{mode}) +@defmac USE_LOAD_PRE_INCREMENT (@var{mode}) A C expression used to determine whether a load preincrement is a good thing to use for a given mode. Defaults to the value of @code{HAVE_PRE_INCREMENT}. +@end defmac -@findex USE_LOAD_PRE_DECREMENT -@item USE_LOAD_PRE_DECREMENT (@var{mode}) +@defmac USE_LOAD_PRE_DECREMENT (@var{mode}) A C expression used to determine whether a load predecrement is a good thing to use for a given mode. Defaults to the value of @code{HAVE_PRE_DECREMENT}. +@end defmac -@findex USE_STORE_POST_INCREMENT -@item USE_STORE_POST_INCREMENT (@var{mode}) +@defmac USE_STORE_POST_INCREMENT (@var{mode}) A C expression used to determine whether a store postincrement is a good thing to use for a given mode. Defaults to the value of @code{HAVE_POST_INCREMENT}. +@end defmac -@findex USE_STORE_POST_DECREMENT -@item USE_STORE_POST_DECREMENT (@var{mode}) +@defmac USE_STORE_POST_DECREMENT (@var{mode}) A C expression used to determine whether a store postdecrement is a good thing to use for a given mode. Defaults to the value of @code{HAVE_POST_DECREMENT}. +@end defmac -@findex USE_STORE_PRE_INCREMENT -@item USE_STORE_PRE_INCREMENT (@var{mode}) +@defmac USE_STORE_PRE_INCREMENT (@var{mode}) This macro is used to determine whether a store preincrement is a good thing to use for a given mode. Defaults to the value of @code{HAVE_PRE_INCREMENT}. +@end defmac -@findex USE_STORE_PRE_DECREMENT -@item USE_STORE_PRE_DECREMENT (@var{mode}) +@defmac USE_STORE_PRE_DECREMENT (@var{mode}) This macro is used to determine whether a store predecrement is a good thing to use for a given mode. Defaults to the value of @code{HAVE_PRE_DECREMENT}. +@end defmac -@findex NO_FUNCTION_CSE -@item NO_FUNCTION_CSE +@defmac NO_FUNCTION_CSE Define this macro if it is as good or better to call a constant function address than to call an address kept in a register. +@end defmac -@findex NO_RECURSIVE_FUNCTION_CSE -@item NO_RECURSIVE_FUNCTION_CSE +@defmac NO_RECURSIVE_FUNCTION_CSE Define this macro if it is as good or better for a function to call itself with an explicit address than to call an address kept in a register. -@end table +@end defmac + +@defmac RANGE_TEST_NON_SHORT_CIRCUIT +Define this macro if a non-short-circuit operation produced by +@samp{fold_range_test ()} is optimal. This macro defaults to true if +@code{BRANCH_COST} is greater than or equal to the value 2. +@end defmac + +@deftypefn {Target Hook} bool TARGET_RTX_COSTS (rtx @var{x}, int @var{code}, int @var{outer_code}, int *@var{total}) +This target hook describes the relative costs of RTL expressions. + +The cost may depend on the precise form of the expression, which is +available for examination in @var{x}, and the rtx code of the expression +in which it is contained, found in @var{outer_code}. @var{code} is the +expression code---redundant, since it can be obtained with +@code{GET_CODE (@var{x})}. + +In implementing this hook, you can use the construct +@code{COSTS_N_INSNS (@var{n})} to specify a cost equal to @var{n} fast +instructions. + +On entry to the hook, @code{*@var{total}} contains a default estimate +for the cost of the expression. The hook should modify this value as +necessary. + +The hook returns true when all subexpressions of @var{x} have been +processed, and false when @code{rtx_cost} should recurse. +@end deftypefn + +@deftypefn {Target Hook} int TARGET_ADDRESS_COST (rtx @var{address}) +This hook computes the cost of an addressing mode that contains +@var{address}. If not defined, the cost is computed from +the @var{address} expression and the @code{TARGET_RTX_COST} hook. + +For most CISC machines, the default cost is a good approximation of the +true cost of the addressing mode. However, on RISC machines, all +instructions normally have the same length and execution time. Hence +all addresses will have equal costs. + +In cases where more than one form of an address is known, the form with +the lowest cost will be used. If multiple forms have the same, lowest, +cost, the one that is the most complex will be used. + +For example, suppose an address that is equal to the sum of a register +and a constant is used twice in the same basic block. When this macro +is not defined, the address will be computed in a register and memory +references will be indirect through that register. On machines where +the cost of the addressing mode containing the sum is no higher than +that of a simple indirect reference, this will produce an additional +instruction and possibly require an additional register. Proper +specification of this macro eliminates this overhead for such machines. + +This hook is never called with an invalid address. + +On machines where an address involving more than one register is as +cheap as an address computation involving only one register, defining +@code{TARGET_ADDRESS_COST} to reflect this can cause two registers to +be live over a region of code where only one would have been if +@code{TARGET_ADDRESS_COST} were not defined in that manner. This effect +should be considered in the definition of this macro. Equivalent costs +should probably only be given to addresses with different numbers of +registers on machines with lots of registers. +@end deftypefn @node Scheduling @section Adjusting the Instruction Scheduler @@ -5504,13 +5522,15 @@ to return the value of the macro @code{MAX_DFA_ISSUE_RATE}. @deftypefn {Target Hook} int TARGET_SCHED_VARIABLE_ISSUE (FILE *@var{file}, int @var{verbose}, rtx @var{insn}, int @var{more}) This hook is executed by the scheduler after it has scheduled an insn from the ready list. It should return the number of insns which can -still be issued in the current cycle. Normally this is -@samp{@w{@var{more} - 1}}. You should define this hook if some insns -take more machine resources than others, so that fewer insns can follow -them in the same cycle. @var{file} is either a null pointer, or a stdio -stream to write any debug output to. @var{verbose} is the verbose level -provided by @option{-fsched-verbose-@var{n}}. @var{insn} is the -instruction that was scheduled. +still be issued in the current cycle. The default is +@samp{@w{@var{more} - 1}} for insns other than @code{CLOBBER} and +@code{USE}, which normally are not counted against the issue rate. +You should define this hook if some insns take more machine resources +than others, so that fewer insns can follow them in the same cycle. +@var{file} is either a null pointer, or a stdio stream to write any +debug output to. @var{verbose} is the verbose level provided by +@option{-fsched-verbose-@var{n}}. @var{insn} is the instruction that +was scheduled. @end deftypefn @deftypefn {Target Hook} int TARGET_SCHED_ADJUST_COST (rtx @var{insn}, rtx @var{link}, rtx @var{dep_insn}, int @var{cost}) @@ -5564,6 +5584,16 @@ scheduling one insn causes other insns to become ready in the same cycle. These other insns can then be taken into account properly. @end deftypefn +@deftypefn {Target Hook} void TARGET_SCHED_DEPENDENCIES_EVALUATION_HOOK (rtx @var{head}, rtx @var{tail}) +This hook is called after evaluation forward dependencies of insns in +chain given by two parameter values (@var{head} and @var{tail} +correspondingly) but before insns scheduling of the insn chain. For +example, it can be used for better insn classification if it requires +analysis of dependencies. This hook can use backward and forward +dependencies of the insn scheduler because they are already +calculated. +@end deftypefn + @deftypefn {Target Hook} void TARGET_SCHED_INIT (FILE *@var{file}, int @var{verbose}, int @var{max_ready}) This hook is executed by the scheduler at the beginning of each block of instructions that are to be scheduled. @var{file} is either a null @@ -5650,6 +5680,30 @@ schedules to choose the best one. The default is no multipass scheduling. @end deftypefn +@deftypefn {Target Hook} int TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD_GUARD (rtx) + +This hook controls what insns from the ready insn queue will be +considered for the multipass insn scheduling. If the hook returns +zero for insn passed as the parameter, the insn will be not chosen to +be issued. + +The default is that any ready insns can be chosen to be issued. +@end deftypefn + +@deftypefn {Target Hook} int TARGET_SCHED_DFA_NEW_CYCLE (FILE *, int, rtx, int, int, int *) + +This hook is called by the insn scheduler before issuing insn passed +as the third parameter on given cycle. If the hook returns nonzero, +the insn is not issued on given processors cycle. Instead of that, +the processor cycle is advanced. If the value passed through the last +parameter is zero, the insn ready queue is not sorted on the new cycle +start as usually. The first parameter passes file for debugging +output. The second one passes the scheduler verbose level of the +debugging output. The forth and the fifth parameter values are +correspondingly processor cycle on which the previous insn has been +issued and the current processor cycle. +@end deftypefn + @deftypefn {Target Hook} void TARGET_SCHED_INIT_DFA_BUBBLES (void) The @acronym{DFA}-based scheduler could take the insertion of nop operations for better insn scheduling into account. It can be done @@ -5685,37 +5739,56 @@ zero. The hook should return @code{NULL} if there are no more nop insns with indexes greater than given index. @end deftypefn +@deftypefn {Target Hook} bool IS_COSTLY_DEPENDENCE (rtx @var{insn1}, rtx @var{insn2}, rtx @var{dep_link}, int @var{dep_cost}, int @var{distance}) +This hook is used to define which dependences are considered costly by +the target, so costly that it is not advisable to schedule the insns that +are involved in the dependence too close to one another. The parameters +to this hook are as follows: The second parameter @var{insn2} is dependent +upon the first parameter @var{insn1}. The dependence between @var{insn1} +and @var{insn2} is represented by the third parameter @var{dep_link}. The +fourth parameter @var{cost} is the cost of the dependence, and the fifth +parameter @var{distance} is the distance in cycles between the two insns. +The hook returns @code{true} if considering the distance between the two +insns the dependence between them is considered costly by the target, +and @code{false} otherwise. + +Defining this hook can be useful in multiple-issue out-of-order machines, +where (a) it's practically hopeless to predict the actual data/resource +delays, however: (b) there's a better chance to predict the actual grouping +that will be formed, and (c) correctly emulating the grouping can be very +important. In such targets one may want to allow issuing dependent insns +closer to one another - i.e, closer than the dependence distance; however, +not in cases of "costly dependences", which this hooks allows to define. +@end deftypefn + Macros in the following table are generated by the program @file{genattr} and can be useful for writing the hooks. -@table @code -@findex TRADITIONAL_PIPELINE_INTERFACE -@item TRADITIONAL_PIPELINE_INTERFACE +@defmac TRADITIONAL_PIPELINE_INTERFACE The macro definition is generated if there is a traditional pipeline description in @file{.md} file. You should also remember that to simplify the insn scheduler sources an empty traditional pipeline description interface is generated even if there is no a traditional pipeline description in the @file{.md} file. The macro can be used to distinguish the two types of the traditional interface. +@end defmac -@findex DFA_PIPELINE_INTERFACE -@item DFA_PIPELINE_INTERFACE +@defmac DFA_PIPELINE_INTERFACE The macro definition is generated if there is an automaton pipeline description in @file{.md} file. You should also remember that to simplify the insn scheduler sources an empty automaton pipeline description interface is generated even if there is no an automaton pipeline description in the @file{.md} file. The macro can be used to distinguish the two types of the automaton interface. +@end defmac -@findex MAX_DFA_ISSUE_RATE -@item MAX_DFA_ISSUE_RATE +@defmac MAX_DFA_ISSUE_RATE The macro definition is generated in the automaton based pipeline description interface. Its value is calculated from the automaton based pipeline description and is equal to maximal number of all insns described in constructions @samp{define_insn_reservation} which can be issued on the same processor cycle. - -@end table +@end defmac @node Sections @section Dividing the Output into Sections (Texts, Data, @dots{}) @@ -5733,45 +5806,36 @@ The compiler must tell the assembler when to switch sections. These macros control what commands to output to tell the assembler this. You can also define additional sections. -@table @code -@findex TEXT_SECTION_ASM_OP -@item TEXT_SECTION_ASM_OP +@defmac TEXT_SECTION_ASM_OP A C expression whose value is a string, including spacing, containing the assembler operation that should precede instructions and read-only data. Normally @code{"\t.text"} is right. +@end defmac -@findex TEXT_SECTION -@item TEXT_SECTION -A C statement that switches to the default section containing instructions. -Normally this is not needed, as simply defining @code{TEXT_SECTION_ASM_OP} -is enough. The MIPS port uses this to sort all functions after all data -declarations. - -@findex HOT_TEXT_SECTION_NAME -@item HOT_TEXT_SECTION_NAME +@defmac HOT_TEXT_SECTION_NAME If defined, a C string constant for the name of the section containing most frequently executed functions of the program. If not defined, GCC will provide a default definition if the target supports named sections. +@end defmac -@findex UNLIKELY_EXECUTED_TEXT_SECTION_NAME -@item UNLIKELY_EXECUTED_TEXT_SECTION_NAME +@defmac UNLIKELY_EXECUTED_TEXT_SECTION_NAME If defined, a C string constant for the name of the section containing unlikely executed functions in the program. +@end defmac -@findex DATA_SECTION_ASM_OP -@item DATA_SECTION_ASM_OP +@defmac DATA_SECTION_ASM_OP A C expression whose value is a string, including spacing, containing the assembler operation to identify the following data as writable initialized data. Normally @code{"\t.data"} is right. +@end defmac -@findex READONLY_DATA_SECTION_ASM_OP -@item READONLY_DATA_SECTION_ASM_OP +@defmac READONLY_DATA_SECTION_ASM_OP A C expression whose value is a string, including spacing, containing the assembler operation to identify the following data as read-only initialized data. +@end defmac -@findex READONLY_DATA_SECTION -@item READONLY_DATA_SECTION +@defmac READONLY_DATA_SECTION A macro naming a function to call to switch to the proper section for read-only data. The default is to use @code{READONLY_DATA_SECTION_ASM_OP} if defined, else fall back to @code{text_section}. @@ -5779,15 +5843,15 @@ if defined, else fall back to @code{text_section}. The most common definition will be @code{data_section}, if the target does not have a special read-only data section, and does not put data in the text section. +@end defmac -@findex SHARED_SECTION_ASM_OP -@item SHARED_SECTION_ASM_OP +@defmac SHARED_SECTION_ASM_OP If defined, a C expression whose value is a string, including spacing, containing the assembler operation to identify the following data as shared data. If not defined, @code{DATA_SECTION_ASM_OP} will be used. +@end defmac -@findex BSS_SECTION_ASM_OP -@item BSS_SECTION_ASM_OP +@defmac BSS_SECTION_ASM_OP If defined, a C expression whose value is a string, including spacing, containing the assembler operation to identify the following data as uninitialized global data. If not defined, and neither @@ -5795,30 +5859,23 @@ uninitialized global data. If not defined, and neither uninitialized global data will be output in the data section if @option{-fno-common} is passed, otherwise @code{ASM_OUTPUT_COMMON} will be used. +@end defmac -@findex SHARED_BSS_SECTION_ASM_OP -@item SHARED_BSS_SECTION_ASM_OP -If defined, a C expression whose value is a string, including spacing, -containing the assembler operation to identify the following data as -uninitialized global shared data. If not defined, and -@code{BSS_SECTION_ASM_OP} is, the latter will be used. - -@findex INIT_SECTION_ASM_OP -@item INIT_SECTION_ASM_OP +@defmac INIT_SECTION_ASM_OP If defined, a C expression whose value is a string, including spacing, containing the assembler operation to identify the following data as initialization code. If not defined, GCC will assume such a section does not exist. +@end defmac -@findex FINI_SECTION_ASM_OP -@item FINI_SECTION_ASM_OP +@defmac FINI_SECTION_ASM_OP If defined, a C expression whose value is a string, including spacing, containing the assembler operation to identify the following data as finalization code. If not defined, GCC will assume such a section does not exist. +@end defmac -@findex CRT_CALL_STATIC_FUNCTION -@item CRT_CALL_STATIC_FUNCTION (@var{section_op}, @var{function}) +@defmac CRT_CALL_STATIC_FUNCTION (@var{section_op}, @var{function}) If defined, an ASM statement that switches to a different section via @var{section_op}, calls @var{function}, and switches back to the text section. This is used in @file{crtstuff.c} if @@ -5828,40 +5885,40 @@ sections. By default, this macro uses a simple function call. Some ports need hand-crafted assembly code to avoid dependencies on registers initialized in the function prologue or to ensure that constant pools don't end up too far way in the text section. +@end defmac -@findex FORCE_CODE_SECTION_ALIGN -@item FORCE_CODE_SECTION_ALIGN +@defmac FORCE_CODE_SECTION_ALIGN If defined, an ASM statement that aligns a code section to some arbitrary boundary. This is used to force all fragments of the @code{.init} and @code{.fini} sections to have to same alignment and thus prevent the linker from having to add any padding. +@end defmac -@findex EXTRA_SECTIONS @findex in_text @findex in_data -@item EXTRA_SECTIONS +@defmac EXTRA_SECTIONS A list of names for sections other than the standard two, which are @code{in_text} and @code{in_data}. You need not define this macro on a system with no other sections (that GCC needs to use). +@end defmac -@findex EXTRA_SECTION_FUNCTIONS @findex text_section @findex data_section -@item EXTRA_SECTION_FUNCTIONS +@defmac EXTRA_SECTION_FUNCTIONS One or more functions to be defined in @file{varasm.c}. These functions should do jobs analogous to those of @code{text_section} and @code{data_section}, for your additional sections. Do not define this macro if you do not define @code{EXTRA_SECTIONS}. +@end defmac -@findex JUMP_TABLES_IN_TEXT_SECTION -@item JUMP_TABLES_IN_TEXT_SECTION +@defmac JUMP_TABLES_IN_TEXT_SECTION Define this macro to be an expression with a nonzero value if jump tables (for @code{tablejump} insns) should be output in the text section, along with the assembler instructions. Otherwise, the readonly data section is used. This macro is irrelevant if there is no separate readonly data section. -@end table +@end defmac @deftypefn {Target Hook} void TARGET_ASM_SELECT_SECTION (tree @var{exp}, int @var{reloc}, unsigned HOST_WIDE_INT @var{align}) Switches to the appropriate section for output of @var{exp}. You can @@ -5902,30 +5959,42 @@ constants in @code{flag_pic} mode in @code{data_section} and everything else in @code{readonly_data_section}. @end deftypefn -@deftypefn {Target Hook} void TARGET_ENCODE_SECTION_INFO (tree @var{decl}, int @var{new_decl_p}) +@deftypefn {Target Hook} void TARGET_ENCODE_SECTION_INFO (tree @var{decl}, rtx @var{rtl}, int @var{new_decl_p}) Define this hook if references to a symbol or a constant must be treated differently depending on something about the variable or function named by the symbol (such as what section it is in). -The hook is executed under two circumstances. One is immediately after -the rtl for @var{decl} that represents a variable or a function has been -created and stored in @code{DECL_RTL(@var{decl})}. The value of the rtl -will be a @code{mem} whose address is a @code{symbol_ref}. The other is -immediately after the rtl for @var{decl} that represents a constant has -been created and stored in @code{TREE_CST_RTL (@var{decl})}. The macro -is called once for each distinct constant in a source file. +The hook is executed immediately after rtl has been created for +@var{decl}, which may be a variable or function declaration or +an entry in the constant pool. In either case, @var{rtl} is the +rtl in question. Do @emph{not} use @code{DECL_RTL (@var{decl})} +in this hook; that field may not have been initialized yet. + +In the case of a constant, it is safe to assume that the rtl is +a @code{mem} whose address is a @code{symbol_ref}. Most decls +will also have this form, but that is not guaranteed. Global +register variables, for instance, will have a @code{reg} for their +rtl. (Normally the right thing to do with such unusual rtl is +leave it alone.) The @var{new_decl_p} argument will be true if this is the first time -that @code{ENCODE_SECTION_INFO} has been invoked on this decl. It will +that @code{TARGET_ENCODE_SECTION_INFO} has been invoked on this decl. It will be false for subsequent invocations, which will happen for duplicate declarations. Whether or not anything must be done for the duplicate declaration depends on whether the hook examines @code{DECL_ATTRIBUTES}. +@var{new_decl_p} is always true when the hook is called for a constant. @cindex @code{SYMBOL_REF_FLAG}, in @code{TARGET_ENCODE_SECTION_INFO} -The usual thing for this hook to do is to record a flag in the -@code{symbol_ref} (such as @code{SYMBOL_REF_FLAG}) or to store a -modified name string in the @code{symbol_ref} (if one bit is not -enough information). +The usual thing for this hook to do is to record flags in the +@code{symbol_ref}, using @code{SYMBOL_REF_FLAG} or @code{SYMBOL_REF_FLAGS}. +Historically, the name string was modified if it was necessary to +encode more than one bit of information, but this practice is now +discouraged; use @code{SYMBOL_REF_FLAGS}. + +The default definition of this hook, @code{default_encode_section_info} +in @file{varasm.c}, sets a number of commonly-useful bits in +@code{SYMBOL_REF_FLAGS}. Check whether the default does what you need +before overriding it. @end deftypefn @deftypefn {Target Hook} const char *TARGET_STRIP_NAME_ENCODING (const char *name) @@ -5976,9 +6045,7 @@ switch statements so that they use relative addresses. @c i rearranged the order of the macros above to try to force one of @c them to the next line, to eliminate an overfull hbox. --mew 10feb93 -@table @code -@findex PIC_OFFSET_TABLE_REGNUM -@item PIC_OFFSET_TABLE_REGNUM +@defmac PIC_OFFSET_TABLE_REGNUM The register number of the register used to address a table of static data addresses in memory. In some cases this register is defined by a processor's ``application binary interface'' (ABI)@. When this macro @@ -5987,15 +6054,15 @@ pointer and frame pointer registers. If this macro is not defined, it is up to the machine-dependent files to allocate such a register (if necessary). Note that this register must be fixed when in use (e.g.@: when @code{flag_pic} is true). +@end defmac -@findex PIC_OFFSET_TABLE_REG_CALL_CLOBBERED -@item PIC_OFFSET_TABLE_REG_CALL_CLOBBERED +@defmac PIC_OFFSET_TABLE_REG_CALL_CLOBBERED Define this macro if the register defined by @code{PIC_OFFSET_TABLE_REGNUM} is clobbered by calls. Do not define this macro if @code{PIC_OFFSET_TABLE_REGNUM} is not defined. +@end defmac -@findex FINALIZE_PIC -@item FINALIZE_PIC +@defmac FINALIZE_PIC By generating position-independent code, when two different programs (A and B) share a common library (libC.a), the text of the library can be shared whether or not the library is linked at the same address for both @@ -6009,9 +6076,9 @@ before. (It is not done before, because in the case of compiling an inline function, it would lead to multiple PIC prologues being included in functions which used inline functions and were compiled to assembly language.) +@end defmac -@findex LEGITIMATE_PIC_OPERAND_P -@item LEGITIMATE_PIC_OPERAND_P (@var{x}) +@defmac LEGITIMATE_PIC_OPERAND_P (@var{x}) A C expression that is nonzero if @var{x} is a legitimate immediate operand on the target machine when generating position independent code. You can assume that @var{x} satisfies @code{CONSTANT_P}, so you need not @@ -6019,7 +6086,7 @@ check this. You can also assume @var{flag_pic} is true, so you need not check it either. You need not define this macro if all constants (including @code{SYMBOL_REF}) can be immediate operands when generating position independent code. -@end table +@end defmac @node Assembler Format @section Defining the Output Assembler Language @@ -6050,93 +6117,107 @@ instructions do. @cindex output of assembler code @c prevent bad page break with this line -This describes the overall framework of an assembler file. - -@table @code -@findex ASM_FILE_START -@item ASM_FILE_START (@var{stream}) -A C expression which outputs to the stdio stream @var{stream} -some appropriate text to go at the start of an assembler file. - -Normally this macro is defined to output a line containing -@samp{#NO_APP}, which is a comment that has no effect on most -assemblers but tells the GNU assembler that it can save time by not -checking for certain assembler constructs. +This describes the overall framework of an assembly file. + +@deftypefn {Target Hook} void TARGET_ASM_FILE_START () +@findex default_file_start +Output to @code{asm_out_file} any text which the assembler expects to +find at the beginning of a file. The default behavior is controlled +by two flags, documented below. Unless your target's assembler is +quite unusual, if you override the default, you should call +@code{default_file_start} at some point in your target hook. This +lets other target files rely on these variables. +@end deftypefn -On systems that use SDB, it is necessary to output certain commands; -see @file{attasm.h}. +@deftypevr {Target Hook} bool TARGET_ASM_FILE_START_APP_OFF +If this flag is true, the text of the macro @code{ASM_APP_OFF} will be +printed as the very first line in the assembly file, unless +@option{-fverbose-asm} is in effect. (If that macro has been defined +to the empty string, this variable has no effect.) With the normal +definition of @code{ASM_APP_OFF}, the effect is to notify the GNU +assembler that it need not bother stripping comments or extra +whitespace from its input. This allows it to work a bit faster. + +The default is false. You should not set it to true unless you have +verified that your port does not generate any extra whitespace or +comments that will cause GAS to issue errors in NO_APP mode. +@end deftypevr -@findex ASM_FILE_END -@item ASM_FILE_END (@var{stream}) -A C expression which outputs to the stdio stream @var{stream} -some appropriate text to go at the end of an assembler file. +@deftypevr {Target Hook} bool TARGET_ASM_FILE_START_FILE_DIRECTIVE +If this flag is true, @code{output_file_directive} will be called +for the primary source file, immediately after printing +@code{ASM_APP_OFF} (if that is enabled). Most ELF assemblers expect +this to be done. The default is false. +@end deftypevr -If this macro is not defined, the default is to output nothing -special at the end of the file. Most systems don't require any -definition. +@deftypefn {Target Hook} void TARGET_ASM_FILE_END () +Output to @code{asm_out_file} any text which the assembler expects +to find at the end of a file. The default is to output nothing. +@end deftypefn -On systems that use SDB, it is necessary to output certain commands; -see @file{attasm.h}. +@deftypefun void file_end_indicate_exec_stack () +Some systems use a common convention, the @samp{.note.GNU-stack} +special section, to indicate whether or not an object file relies on +the stack being executable. If your system uses this convention, you +should define @code{TARGET_ASM_FILE_END} to this function. If you +need to do other things in that hook, have your hook function call +this function. +@end deftypefun -@findex ASM_COMMENT_START -@item ASM_COMMENT_START +@defmac ASM_COMMENT_START A C string constant describing how to begin a comment in the target assembler language. The compiler assumes that the comment will end at the end of the line. +@end defmac -@findex ASM_APP_ON -@item ASM_APP_ON +@defmac ASM_APP_ON A C string constant for text to be output before each @code{asm} statement or group of consecutive ones. Normally this is @code{"#APP"}, which is a comment that has no effect on most assemblers but tells the GNU assembler that it must check the lines that follow for all valid assembler constructs. +@end defmac -@findex ASM_APP_OFF -@item ASM_APP_OFF +@defmac ASM_APP_OFF A C string constant for text to be output after each @code{asm} statement or group of consecutive ones. Normally this is @code{"#NO_APP"}, which tells the GNU assembler to resume making the time-saving assumptions that are valid for ordinary compiler output. +@end defmac -@findex ASM_OUTPUT_SOURCE_FILENAME -@item ASM_OUTPUT_SOURCE_FILENAME (@var{stream}, @var{name}) +@defmac ASM_OUTPUT_SOURCE_FILENAME (@var{stream}, @var{name}) A C statement to output COFF information or DWARF debugging information which indicates that filename @var{name} is the current source file to the stdio stream @var{stream}. This macro need not be defined if the standard form of output for the file format in use is appropriate. +@end defmac -@findex OUTPUT_QUOTED_STRING -@item OUTPUT_QUOTED_STRING (@var{stream}, @var{string}) +@defmac OUTPUT_QUOTED_STRING (@var{stream}, @var{string}) A C statement to output the string @var{string} to the stdio stream @var{stream}. If you do not call the function @code{output_quoted_string} in your config files, GCC will only call it to output filenames to the assembler source. So you can use it to canonicalize the format of the filename using this macro. +@end defmac -@findex ASM_OUTPUT_SOURCE_LINE -@item ASM_OUTPUT_SOURCE_LINE (@var{stream}, @var{line}) +@defmac ASM_OUTPUT_SOURCE_LINE (@var{stream}, @var{line}, @var{counter}) A C statement to output DBX or SDB debugging information before code for line number @var{line} of the current source file to the -stdio stream @var{stream}. +stdio stream @var{stream}. @var{counter} is the number of time the +macro was invoked, including the current invocation; it is intended +to generate unique labels in the assembly output. This macro need not be defined if the standard form of debugging information for the debugger in use is appropriate. +@end defmac -@findex ASM_OUTPUT_IDENT -@item ASM_OUTPUT_IDENT (@var{stream}, @var{string}) +@defmac ASM_OUTPUT_IDENT (@var{stream}, @var{string}) A C statement to output something to the assembler file to handle a @samp{#ident} directive containing the text @var{string}. If this macro is not defined, nothing is output for a @samp{#ident} directive. - -@findex OBJC_PROLOGUE -@item OBJC_PROLOGUE -A C statement to output any assembler statements which are required to -precede any Objective-C object definitions or message sending. The -statement is executed only when compiling an Objective-C program. -@end table +@end defmac @deftypefn {Target Hook} void TARGET_ASM_NAMED_SECTION (const char *@var{name}, unsigned int @var{flags}, unsigned int @var{align}) Output assembly directives to switch to section @var{name}. The section @@ -6202,9 +6283,7 @@ The default implementation of this hook will use the when the relevant string is @code{NULL}. @end deftypefn -@table @code -@findex OUTPUT_ADDR_CONST_EXTRA -@item OUTPUT_ADDR_CONST_EXTRA (@var{stream}, @var{x}, @var{fail}) +@defmac OUTPUT_ADDR_CONST_EXTRA (@var{stream}, @var{x}, @var{fail}) A C statement to recognize @var{rtx} patterns that @code{output_addr_const} can't deal with, and output assembly code to @var{stream} corresponding to the pattern @var{x}. This may be used to @@ -6214,9 +6293,9 @@ If @code{OUTPUT_ADDR_CONST_EXTRA} fails to recognize a pattern, it must @code{goto fail}, so that a standard error message is printed. If it prints an error message itself, by calling, for example, @code{output_operand_lossage}, it may just complete normally. +@end defmac -@findex ASM_OUTPUT_ASCII -@item ASM_OUTPUT_ASCII (@var{stream}, @var{ptr}, @var{len}) +@defmac ASM_OUTPUT_ASCII (@var{stream}, @var{ptr}, @var{len}) A C statement to output to the stdio stream @var{stream} an assembler instruction to assemble a string constant containing the @var{len} bytes at @var{ptr}. @var{ptr} will be a C expression of type @@ -6225,24 +6304,24 @@ bytes at @var{ptr}. @var{ptr} will be a C expression of type If the assembler has a @code{.ascii} pseudo-op as found in the Berkeley Unix assembler, do not define the macro @code{ASM_OUTPUT_ASCII}. +@end defmac -@findex ASM_OUTPUT_FDESC -@item ASM_OUTPUT_FDESC (@var{stream}, @var{decl}, @var{n}) +@defmac ASM_OUTPUT_FDESC (@var{stream}, @var{decl}, @var{n}) A C statement to output word @var{n} of a function descriptor for @var{decl}. This must be defined if @code{TARGET_VTABLE_USES_DESCRIPTORS} is defined, and is otherwise unused. +@end defmac -@findex CONSTANT_POOL_BEFORE_FUNCTION -@item CONSTANT_POOL_BEFORE_FUNCTION +@defmac CONSTANT_POOL_BEFORE_FUNCTION You may define this macro as a C expression. You should define the expression to have a nonzero value if GCC should output the constant pool for a function before the code for the function, or a zero value if GCC should output the constant pool after the function. If you do not define this macro, the usual case, GCC will output the constant pool before the function. +@end defmac -@findex ASM_OUTPUT_POOL_PROLOGUE -@item ASM_OUTPUT_POOL_PROLOGUE (@var{file}, @var{funname}, @var{fundecl}, @var{size}) +@defmac ASM_OUTPUT_POOL_PROLOGUE (@var{file}, @var{funname}, @var{fundecl}, @var{size}) A C statement to output assembler commands to define the start of the constant pool for a function. @var{funname} is a string giving the name of the function. Should the return type of the function @@ -6252,9 +6331,9 @@ immediately after this call. If no constant-pool prefix is required, the usual case, this macro need not be defined. +@end defmac -@findex ASM_OUTPUT_SPECIAL_POOL_ENTRY -@item ASM_OUTPUT_SPECIAL_POOL_ENTRY (@var{file}, @var{x}, @var{mode}, @var{align}, @var{labelno}, @var{jumpto}) +@defmac ASM_OUTPUT_SPECIAL_POOL_ENTRY (@var{file}, @var{x}, @var{mode}, @var{align}, @var{labelno}, @var{jumpto}) A C statement (with or without semicolon) to output a constant in the constant pool, if it needs special treatment. (This macro need not do anything for RTL expressions that can be output normally.) @@ -6271,25 +6350,18 @@ the address of this pool entry. The definition of this macro is responsible for outputting the label definition at the proper place. Here is how to do this: -@example -ASM_OUTPUT_INTERNAL_LABEL (@var{file}, "LC", @var{labelno}); -@end example +@smallexample +@code{(*targetm.asm_out.internal_label)} (@var{file}, "LC", @var{labelno}); +@end smallexample When you output a pool entry specially, you should end with a @code{goto} to the label @var{jumpto}. This will prevent the same pool entry from being output a second time in the usual manner. You need not define this macro if it would do nothing. +@end defmac -@findex CONSTANT_AFTER_FUNCTION_P -@item CONSTANT_AFTER_FUNCTION_P (@var{exp}) -Define this macro as a C expression which is nonzero if the constant -@var{exp}, of type @code{tree}, should be output after the code for a -function. The compiler will normally output all constants before the -function; you need not define this macro if this is OK@. - -@findex ASM_OUTPUT_POOL_EPILOGUE -@item ASM_OUTPUT_POOL_EPILOGUE (@var{file} @var{funname} @var{fundecl} @var{size}) +@defmac ASM_OUTPUT_POOL_EPILOGUE (@var{file} @var{funname} @var{fundecl} @var{size}) A C statement to output assembler commands to at the end of the constant pool for a function. @var{funname} is a string giving the name of the function. Should the return type of the function be required, you can @@ -6298,15 +6370,15 @@ constant pool that GCC wrote immediately before this call. If no constant-pool epilogue is required, the usual case, you need not define this macro. +@end defmac -@findex IS_ASM_LOGICAL_LINE_SEPARATOR -@item IS_ASM_LOGICAL_LINE_SEPARATOR (@var{C}) +@defmac IS_ASM_LOGICAL_LINE_SEPARATOR (@var{C}) Define this macro as a C expression which is nonzero if @var{C} is used as a logical line separator by the assembler. If you do not define this macro, the default is that only the character @samp{;} is treated as a logical line separator. -@end table +@end defmac @deftypevr {Target Hook} {const char *} TARGET_ASM_OPEN_PAREN @deftypevrx {Target Hook} {const char *} TARGET_ASM_CLOSE_PAREN @@ -6318,13 +6390,9 @@ default to normal parentheses, which is correct for most assemblers. These macros are provided by @file{real.h} for writing the definitions of @code{ASM_OUTPUT_DOUBLE} and the like: -@table @code -@item REAL_VALUE_TO_TARGET_SINGLE (@var{x}, @var{l}) -@itemx REAL_VALUE_TO_TARGET_DOUBLE (@var{x}, @var{l}) -@itemx REAL_VALUE_TO_TARGET_LONG_DOUBLE (@var{x}, @var{l}) -@findex REAL_VALUE_TO_TARGET_SINGLE -@findex REAL_VALUE_TO_TARGET_DOUBLE -@findex REAL_VALUE_TO_TARGET_LONG_DOUBLE +@defmac REAL_VALUE_TO_TARGET_SINGLE (@var{x}, @var{l}) +@defmacx REAL_VALUE_TO_TARGET_DOUBLE (@var{x}, @var{l}) +@defmacx REAL_VALUE_TO_TARGET_LONG_DOUBLE (@var{x}, @var{l}) These translate @var{x}, of type @code{REAL_VALUE_TYPE}, to the target's floating point representation, and store its bit pattern in the variable @var{l}. For @code{REAL_VALUE_TO_TARGET_SINGLE}, this variable should @@ -6338,7 +6406,7 @@ host machine. The array element values are designed so that you can print them out using @code{fprintf} in the order they should appear in the target machine's memory. -@end table +@end defmac @node Uninitialized Data @subsection Output of Uninitialized Variables @@ -6346,9 +6414,7 @@ machine's memory. Each of the macros in this section is used to do the whole job of outputting a single uninitialized variable. -@table @code -@findex ASM_OUTPUT_COMMON -@item ASM_OUTPUT_COMMON (@var{stream}, @var{name}, @var{size}, @var{rounded}) +@defmac ASM_OUTPUT_COMMON (@var{stream}, @var{name}, @var{size}, @var{rounded}) A C statement (sans semicolon) to output to the stdio stream @var{stream} the assembler definition of a common-label named @var{name} whose size is @var{size} bytes. The variable @var{rounded} @@ -6360,32 +6426,32 @@ assembler syntax for defining the name, and a newline. This macro controls how the assembler definitions of uninitialized common global variables are output. +@end defmac -@findex ASM_OUTPUT_ALIGNED_COMMON -@item ASM_OUTPUT_ALIGNED_COMMON (@var{stream}, @var{name}, @var{size}, @var{alignment}) +@defmac ASM_OUTPUT_ALIGNED_COMMON (@var{stream}, @var{name}, @var{size}, @var{alignment}) Like @code{ASM_OUTPUT_COMMON} except takes the required alignment as a separate, explicit argument. If you define this macro, it is used in place of @code{ASM_OUTPUT_COMMON}, and gives you more flexibility in handling the required alignment of the variable. The alignment is specified as the number of bits. +@end defmac -@findex ASM_OUTPUT_ALIGNED_DECL_COMMON -@item ASM_OUTPUT_ALIGNED_DECL_COMMON (@var{stream}, @var{decl}, @var{name}, @var{size}, @var{alignment}) +@defmac ASM_OUTPUT_ALIGNED_DECL_COMMON (@var{stream}, @var{decl}, @var{name}, @var{size}, @var{alignment}) Like @code{ASM_OUTPUT_ALIGNED_COMMON} except that @var{decl} of the variable to be output, if there is one, or @code{NULL_TREE} if there is no corresponding variable. If you define this macro, GCC will use it in place of both @code{ASM_OUTPUT_COMMON} and @code{ASM_OUTPUT_ALIGNED_COMMON}. Define this macro when you need to see the variable's decl in order to chose what to output. +@end defmac -@findex ASM_OUTPUT_SHARED_COMMON -@item ASM_OUTPUT_SHARED_COMMON (@var{stream}, @var{name}, @var{size}, @var{rounded}) +@defmac ASM_OUTPUT_SHARED_COMMON (@var{stream}, @var{name}, @var{size}, @var{rounded}) If defined, it is similar to @code{ASM_OUTPUT_COMMON}, except that it is used when @var{name} is shared. If not defined, @code{ASM_OUTPUT_COMMON} will be used. +@end defmac -@findex ASM_OUTPUT_BSS -@item ASM_OUTPUT_BSS (@var{stream}, @var{decl}, @var{name}, @var{size}, @var{rounded}) +@defmac ASM_OUTPUT_BSS (@var{stream}, @var{decl}, @var{name}, @var{size}, @var{rounded}) A C statement (sans semicolon) to output to the stdio stream @var{stream} the assembler definition of uninitialized global @var{decl} named @var{name} whose size is @var{size} bytes. The variable @var{rounded} @@ -6404,9 +6470,9 @@ is not defined for all targets. If this macro and @code{ASM_OUTPUT_ALIGNED_BSS} are not defined then @code{ASM_OUTPUT_COMMON} or @code{ASM_OUTPUT_ALIGNED_COMMON} or @code{ASM_OUTPUT_ALIGNED_DECL_COMMON} is used. +@end defmac -@findex ASM_OUTPUT_ALIGNED_BSS -@item ASM_OUTPUT_ALIGNED_BSS (@var{stream}, @var{decl}, @var{name}, @var{size}, @var{alignment}) +@defmac ASM_OUTPUT_ALIGNED_BSS (@var{stream}, @var{decl}, @var{name}, @var{size}, @var{alignment}) Like @code{ASM_OUTPUT_BSS} except takes the required alignment as a separate, explicit argument. If you define this macro, it is used in place of @code{ASM_OUTPUT_BSS}, and gives you more flexibility in @@ -6415,15 +6481,15 @@ as the number of bits. Try to use function @code{asm_output_aligned_bss} defined in file @file{varasm.c} when defining this macro. +@end defmac -@findex ASM_OUTPUT_SHARED_BSS -@item ASM_OUTPUT_SHARED_BSS (@var{stream}, @var{decl}, @var{name}, @var{size}, @var{rounded}) +@defmac ASM_OUTPUT_SHARED_BSS (@var{stream}, @var{decl}, @var{name}, @var{size}, @var{rounded}) If defined, it is similar to @code{ASM_OUTPUT_BSS}, except that it is used when @var{name} is shared. If not defined, @code{ASM_OUTPUT_BSS} will be used. +@end defmac -@findex ASM_OUTPUT_LOCAL -@item ASM_OUTPUT_LOCAL (@var{stream}, @var{name}, @var{size}, @var{rounded}) +@defmac ASM_OUTPUT_LOCAL (@var{stream}, @var{name}, @var{size}, @var{rounded}) A C statement (sans semicolon) to output to the stdio stream @var{stream} the assembler definition of a local-common-label named @var{name} whose size is @var{size} bytes. The variable @var{rounded} @@ -6435,30 +6501,30 @@ assembler syntax for defining the name, and a newline. This macro controls how the assembler definitions of uninitialized static variables are output. +@end defmac -@findex ASM_OUTPUT_ALIGNED_LOCAL -@item ASM_OUTPUT_ALIGNED_LOCAL (@var{stream}, @var{name}, @var{size}, @var{alignment}) +@defmac ASM_OUTPUT_ALIGNED_LOCAL (@var{stream}, @var{name}, @var{size}, @var{alignment}) Like @code{ASM_OUTPUT_LOCAL} except takes the required alignment as a separate, explicit argument. If you define this macro, it is used in place of @code{ASM_OUTPUT_LOCAL}, and gives you more flexibility in handling the required alignment of the variable. The alignment is specified as the number of bits. +@end defmac -@findex ASM_OUTPUT_ALIGNED_DECL_LOCAL -@item ASM_OUTPUT_ALIGNED_DECL_LOCAL (@var{stream}, @var{decl}, @var{name}, @var{size}, @var{alignment}) +@defmac ASM_OUTPUT_ALIGNED_DECL_LOCAL (@var{stream}, @var{decl}, @var{name}, @var{size}, @var{alignment}) Like @code{ASM_OUTPUT_ALIGNED_DECL} except that @var{decl} of the variable to be output, if there is one, or @code{NULL_TREE} if there is no corresponding variable. If you define this macro, GCC will use it in place of both @code{ASM_OUTPUT_DECL} and @code{ASM_OUTPUT_ALIGNED_DECL}. Define this macro when you need to see the variable's decl in order to chose what to output. +@end defmac -@findex ASM_OUTPUT_SHARED_LOCAL -@item ASM_OUTPUT_SHARED_LOCAL (@var{stream}, @var{name}, @var{size}, @var{rounded}) +@defmac ASM_OUTPUT_SHARED_LOCAL (@var{stream}, @var{name}, @var{size}, @var{rounded}) If defined, it is similar to @code{ASM_OUTPUT_LOCAL}, except that it is used when @var{name} is shared. If not defined, @code{ASM_OUTPUT_LOCAL} will be used. -@end table +@end defmac @node Label Output @subsection Output and Generation of Labels @@ -6466,19 +6532,17 @@ will be used. @c prevent bad page break with this line This is about outputting labels. -@table @code -@findex ASM_OUTPUT_LABEL @findex assemble_name -@item ASM_OUTPUT_LABEL (@var{stream}, @var{name}) +@defmac ASM_OUTPUT_LABEL (@var{stream}, @var{name}) A C statement (sans semicolon) to output to the stdio stream @var{stream} the assembler definition of a label named @var{name}. Use the expression @code{assemble_name (@var{stream}, @var{name})} to output the name itself; before and after that, output the additional assembler syntax for defining the name, and a newline. A default definition of this macro is provided which is correct for most systems. +@end defmac -@findex SIZE_ASM_OP -@item SIZE_ASM_OP +@defmac SIZE_ASM_OP A C string containing the appropriate assembler directive to specify the size of a symbol, without any arguments. On systems that use ELF, the default (in @file{config/elfos.h}) is @samp{"\t.size\t"}; on other @@ -6489,21 +6553,21 @@ of @code{ASM_OUTPUT_SIZE_DIRECTIVE} and @code{ASM_OUTPUT_MEASURED_SIZE} for your system. If you need your own custom definitions of those macros, or if you do not need explicit symbol sizes at all, do not define this macro. +@end defmac -@findex ASM_OUTPUT_SIZE_DIRECTIVE -@item ASM_OUTPUT_SIZE_DIRECTIVE (@var{stream}, @var{name}, @var{size}) +@defmac ASM_OUTPUT_SIZE_DIRECTIVE (@var{stream}, @var{name}, @var{size}) A C statement (sans semicolon) to output to the stdio stream @var{stream} a directive telling the assembler that the size of the symbol @var{name} is @var{size}. @var{size} is a @code{HOST_WIDE_INT}. If you define @code{SIZE_ASM_OP}, a default definition of this macro is provided. +@end defmac -@findex ASM_OUTPUT_MEASURED_SIZE -@item ASM_OUTPUT_MEASURED_SIZE (@var{stream}, @var{name}) +@defmac ASM_OUTPUT_MEASURED_SIZE (@var{stream}, @var{name}) A C statement (sans semicolon) to output to the stdio stream @var{stream} a directive telling the assembler to calculate the size of the symbol @var{name} by subtracting its address from the current -address. +address. If you define @code{SIZE_ASM_OP}, a default definition of this macro is provided. The default assumes that the assembler recognizes a special @@ -6511,9 +6575,9 @@ provided. The default assumes that the assembler recognizes a special the difference between this and another symbol. If your assembler does not recognize @samp{.} or cannot do calculations with it, you will need to redefine @code{ASM_OUTPUT_MEASURED_SIZE} to use some other technique. +@end defmac -@findex TYPE_ASM_OP -@item TYPE_ASM_OP +@defmac TYPE_ASM_OP A C string containing the appropriate assembler directive to specify the type of a symbol, without any arguments. On systems that use ELF, the default (in @file{config/elfos.h}) is @samp{"\t.type\t"}; on other @@ -6523,9 +6587,9 @@ Define this macro only if it is correct to use the default definition of @code{ASM_OUTPUT_TYPE_DIRECTIVE} for your system. If you need your own custom definition of this macro, or if you do not need explicit symbol types at all, do not define this macro. +@end defmac -@findex TYPE_OPERAND_FMT -@item TYPE_OPERAND_FMT +@defmac TYPE_OPERAND_FMT A C string which specifies (using @code{printf} syntax) the format of the second operand to @code{TYPE_ASM_OP}. On systems that use ELF, the default (in @file{config/elfos.h}) is @samp{"@@%s"}; on other systems, @@ -6535,9 +6599,9 @@ Define this macro only if it is correct to use the default definition of @code{ASM_OUTPUT_TYPE_DIRECTIVE} for your system. If you need your own custom definition of this macro, or if you do not need explicit symbol types at all, do not define this macro. +@end defmac -@findex ASM_OUTPUT_TYPE_DIRECTIVE -@item ASM_OUTPUT_TYPE_DIRECTIVE (@var{stream}, @var{type}) +@defmac ASM_OUTPUT_TYPE_DIRECTIVE (@var{stream}, @var{type}) A C statement (sans semicolon) to output to the stdio stream @var{stream} a directive telling the assembler that the type of the symbol @var{name} is @var{type}. @var{type} is a C string; currently, @@ -6546,9 +6610,9 @@ you should not count on this. If you define @code{TYPE_ASM_OP} and @code{TYPE_OPERAND_FMT}, a default definition of this macro is provided. +@end defmac -@findex ASM_DECLARE_FUNCTION_NAME -@item ASM_DECLARE_FUNCTION_NAME (@var{stream}, @var{name}, @var{decl}) +@defmac ASM_DECLARE_FUNCTION_NAME (@var{stream}, @var{name}, @var{decl}) A C statement (sans semicolon) to output to the stdio stream @var{stream} any text necessary for declaring the name @var{name} of a function which is being defined. This macro is responsible for @@ -6561,9 +6625,9 @@ usual manner as a label (by means of @code{ASM_OUTPUT_LABEL}). You may wish to use @code{ASM_OUTPUT_TYPE_DIRECTIVE} in the definition of this macro. +@end defmac -@findex ASM_DECLARE_FUNCTION_SIZE -@item ASM_DECLARE_FUNCTION_SIZE (@var{stream}, @var{name}, @var{decl}) +@defmac ASM_DECLARE_FUNCTION_SIZE (@var{stream}, @var{name}, @var{decl}) A C statement (sans semicolon) to output to the stdio stream @var{stream} any text necessary for declaring the size of a function which is being defined. The argument @var{name} is the name of the @@ -6574,9 +6638,9 @@ If this macro is not defined, then the function size is not defined. You may wish to use @code{ASM_OUTPUT_MEASURED_SIZE} in the definition of this macro. +@end defmac -@findex ASM_DECLARE_OBJECT_NAME -@item ASM_DECLARE_OBJECT_NAME (@var{stream}, @var{name}, @var{decl}) +@defmac ASM_DECLARE_OBJECT_NAME (@var{stream}, @var{name}, @var{decl}) A C statement (sans semicolon) to output to the stdio stream @var{stream} any text necessary for declaring the name @var{name} of an initialized variable which is being defined. This macro must output the @@ -6588,9 +6652,9 @@ usual manner as a label (by means of @code{ASM_OUTPUT_LABEL}). You may wish to use @code{ASM_OUTPUT_TYPE_DIRECTIVE} and/or @code{ASM_OUTPUT_SIZE_DIRECTIVE} in the definition of this macro. +@end defmac -@findex ASM_DECLARE_CONSTANT_NAME -@item ASM_DECLARE_CONSTANT_NAME (@var{stream}, @var{name}, @var{exp}, @var{size}) +@defmac ASM_DECLARE_CONSTANT_NAME (@var{stream}, @var{name}, @var{exp}, @var{size}) A C statement (sans semicolon) to output to the stdio stream @var{stream} any text necessary for declaring the name @var{name} of a constant which is being defined. This macro is responsible for @@ -6604,18 +6668,18 @@ usual manner as a label (by means of @code{ASM_OUTPUT_LABEL}). You may wish to use @code{ASM_OUTPUT_TYPE_DIRECTIVE} in the definition of this macro. +@end defmac -@findex ASM_DECLARE_REGISTER_GLOBAL -@item ASM_DECLARE_REGISTER_GLOBAL (@var{stream}, @var{decl}, @var{regno}, @var{name}) +@defmac ASM_DECLARE_REGISTER_GLOBAL (@var{stream}, @var{decl}, @var{regno}, @var{name}) A C statement (sans semicolon) to output to the stdio stream @var{stream} any text necessary for claiming a register @var{regno} for a global variable @var{decl} with name @var{name}. If you don't define this macro, that is equivalent to defining it to do nothing. +@end defmac -@findex ASM_FINISH_DECLARE_OBJECT -@item ASM_FINISH_DECLARE_OBJECT (@var{stream}, @var{decl}, @var{toplevel}, @var{atend}) +@defmac ASM_FINISH_DECLARE_OBJECT (@var{stream}, @var{decl}, @var{toplevel}, @var{atend}) A C statement (sans semicolon) to finish up declaring a variable name once the compiler has processed its initializer fully and thus has had a chance to determine the size of an array when controlled by an @@ -6627,7 +6691,7 @@ nothing. You may wish to use @code{ASM_OUTPUT_SIZE_DIRECTIVE} and/or @code{ASM_OUTPUT_MEASURED_SIZE} in the definition of this macro. -@end table +@end defmac @deftypefn {Target Hook} void TARGET_ASM_GLOBALIZE_LABEL (FILE *@var{stream}, const char *@var{name}) This target hook is a function to output to the stdio stream @@ -6638,9 +6702,7 @@ The default implementation relies on a proper definition of @code{GLOBAL_ASM_OP}. @end deftypefn -@table @code -@findex ASM_WEAKEN_LABEL -@item ASM_WEAKEN_LABEL (@var{stream}, @var{name}) +@defmac ASM_WEAKEN_LABEL (@var{stream}, @var{name}) A C statement (sans semicolon) to output to the stdio stream @var{stream} some commands that will make the label @var{name} weak; that is, available for reference from other files but only used if @@ -6652,9 +6714,9 @@ for making that name weak, and a newline. If you don't define this macro or @code{ASM_WEAKEN_DECL}, GCC will not support weak symbols and you should not define the @code{SUPPORTS_WEAK} macro. +@end defmac -@findex ASM_WEAKEN_DECL -@item ASM_WEAKEN_DECL (@var{stream}, @var{decl}, @var{name}, @var{value}) +@defmac ASM_WEAKEN_DECL (@var{stream}, @var{decl}, @var{name}, @var{value}) Combines (and replaces) the function of @code{ASM_WEAKEN_LABEL} and @code{ASM_OUTPUT_WEAK_ALIAS}, allowing access to the associated function or variable decl. If @var{value} is not @code{NULL}, this C statement @@ -6662,9 +6724,9 @@ should output to the stdio stream @var{stream} assembler code which defines (equates) the weak symbol @var{name} to have the value @var{value}. If @var{value} is @code{NULL}, it should output commands to make @var{name} weak. +@end defmac -@findex SUPPORTS_WEAK -@item SUPPORTS_WEAK +@defmac SUPPORTS_WEAK A C expression which evaluates to true if the target supports weak symbols. If you don't define this macro, @file{defaults.h} provides a default @@ -6672,18 +6734,18 @@ definition. If either @code{ASM_WEAKEN_LABEL} or @code{ASM_WEAKEN_DECL} is defined, the default definition is @samp{1}; otherwise, it is @samp{0}. Define this macro if you want to control weak symbol support with a compiler flag such as @option{-melf}. +@end defmac -@findex MAKE_DECL_ONE_ONLY (@var{decl}) -@item MAKE_DECL_ONE_ONLY +@defmac MAKE_DECL_ONE_ONLY (@var{decl}) A C statement (sans semicolon) to mark @var{decl} to be emitted as a public symbol such that extra copies in multiple translation units will be discarded by the linker. Define this macro if your object file format provides support for this concept, such as the @samp{COMDAT} section flags in the Microsoft Windows PE/COFF format, and this support requires changes to @var{decl}, such as putting it in a separate section. +@end defmac -@findex SUPPORTS_ONE_ONLY -@item SUPPORTS_ONE_ONLY +@defmac SUPPORTS_ONE_ONLY A C expression which evaluates to true if the target supports one-only semantics. @@ -6693,6 +6755,7 @@ definition is @samp{1}; otherwise, it is @samp{0}. Define this macro if you want to control one-only symbol support with a compiler flag, or if setting the @code{DECL_ONE_ONLY} flag is enough to mark a declaration to be emitted as one-only. +@end defmac @deftypefn {Target Hook} void TARGET_ASM_ASSEMBLE_VISIBILITY (tree @var{decl}, const char *@var{visibility}) This target hook is a function to output to @var{asm_out_file} some @@ -6700,8 +6763,7 @@ commands that will make the symbol(s) associated with @var{decl} have hidden, protected or internal visibility as specified by @var{visibility}. @end deftypefn -@findex ASM_OUTPUT_EXTERNAL -@item ASM_OUTPUT_EXTERNAL (@var{stream}, @var{decl}, @var{name}) +@defmac ASM_OUTPUT_EXTERNAL (@var{stream}, @var{decl}, @var{name}) A C statement (sans semicolon) to output to the stdio stream @var{stream} any text necessary for declaring the name of an external symbol named @var{name} which is referenced in this compilation but @@ -6710,35 +6772,31 @@ declaration. This macro need not be defined if it does not need to output anything. The GNU assembler and most Unix assemblers don't require anything. +@end defmac -@findex ASM_OUTPUT_EXTERNAL_LIBCALL -@item ASM_OUTPUT_EXTERNAL_LIBCALL (@var{stream}, @var{symref}) -A C statement (sans semicolon) to output on @var{stream} an assembler +@deftypefn {Target Hook} void TARGET_ASM_EXTERNAL_LIBCALL (rtx @var{symref}) +This target hook is a function to output to @var{asm_out_file} an assembler pseudo-op to declare a library function name external. The name of the -library function is given by @var{symref}, which has type @code{rtx} and -is a @code{symbol_ref}. - -This macro need not be defined if it does not need to output anything. -The GNU assembler and most Unix assemblers don't require anything. +library function is given by @var{symref}, which is a @code{symbol_ref}. +@end deftypefn -@findex ASM_OUTPUT_LABELREF -@item ASM_OUTPUT_LABELREF (@var{stream}, @var{name}) +@defmac ASM_OUTPUT_LABELREF (@var{stream}, @var{name}) A C statement (sans semicolon) to output to the stdio stream @var{stream} a reference in assembler syntax to a label named @var{name}. This should add @samp{_} to the front of the name, if that is customary on your operating system, as it is in most Berkeley Unix systems. This macro is used in @code{assemble_name}. +@end defmac -@findex ASM_OUTPUT_SYMBOL_REF -@item ASM_OUTPUT_SYMBOL_REF (@var{stream}, @var{sym}) +@defmac ASM_OUTPUT_SYMBOL_REF (@var{stream}, @var{sym}) A C statement (sans semicolon) to output a reference to @code{SYMBOL_REF} @var{sym}. If not defined, @code{assemble_name} will be used to output the name of the symbol. This macro may be used to modify the way a symbol is referenced depending on information encoded by @code{TARGET_ENCODE_SECTION_INFO}. +@end defmac -@findex ASM_OUTPUT_LABEL_REF -@item ASM_OUTPUT_LABEL_REF (@var{stream}, @var{buf}) +@defmac ASM_OUTPUT_LABEL_REF (@var{stream}, @var{buf}) A C statement (sans semicolon) to output a reference to @var{buf}, the result of @code{ASM_GENERATE_INTERNAL_LABEL}. If not defined, @code{assemble_name} will be used to output the name of the symbol. @@ -6746,11 +6804,11 @@ This macro is not used by @code{output_asm_label}, or the @code{%l} specifier that calls it; the intention is that this macro should be set when it is necessary to output a label differently when its address is being taken. +@end defmac -@findex ASM_OUTPUT_INTERNAL_LABEL -@item ASM_OUTPUT_INTERNAL_LABEL (@var{stream}, @var{prefix}, @var{num}) -A C statement to output to the stdio stream @var{stream} a label whose -name is made from the string @var{prefix} and the number @var{num}. +@deftypefn {Target Hook} void TARGET_ASM_INTERNAL_LABEL (FILE *@var{stream}, const char *@var{prefix}, unsigned long @var{labelno}) +A function to output to the stdio stream @var{stream} a label whose +name is made from the string @var{prefix} and the number @var{labelno}. It is absolutely essential that these labels be distinct from the labels used for user-level functions and variables. Otherwise, certain programs @@ -6762,14 +6820,10 @@ should be excluded; on many systems, the letter @samp{L} at the beginning of a label has this effect. You should find out what convention your system uses, and follow it. -The usual definition of this macro is as follows: - -@example -fprintf (@var{stream}, "L%s%d:\n", @var{prefix}, @var{num}) -@end example +The default version of this function utilizes ASM_GENERATE_INTERNAL_LABEL. +@end deftypefn -@findex ASM_OUTPUT_DEBUG_LABEL -@item ASM_OUTPUT_DEBUG_LABEL (@var{stream}, @var{prefix}, @var{num}) +@defmac ASM_OUTPUT_DEBUG_LABEL (@var{stream}, @var{prefix}, @var{num}) A C statement to output to the stdio stream @var{stream} a debug info label whose name is made from the string @var{prefix} and the number @var{num}. This is useful for VLIW targets, where debug info labels @@ -6778,16 +6832,16 @@ systems, branch target labels must be at the beginning of instruction bundles, but debug info labels can occur in the middle of instruction bundles. -If this macro is not defined, then @code{ASM_OUTPUT_INTERNAL_LABEL} will be +If this macro is not defined, then @code{(*targetm.asm_out.internal_label)} will be used. +@end defmac -@findex ASM_GENERATE_INTERNAL_LABEL -@item ASM_GENERATE_INTERNAL_LABEL (@var{string}, @var{prefix}, @var{num}) +@defmac ASM_GENERATE_INTERNAL_LABEL (@var{string}, @var{prefix}, @var{num}) A C statement to store into the string @var{string} a label whose name is made from the string @var{prefix} and the number @var{num}. This string, when output subsequently by @code{assemble_name}, should -produce the output that @code{ASM_OUTPUT_INTERNAL_LABEL} would produce +produce the output that @code{(*targetm.asm_out.internal_label)} would produce with the same @var{prefix} and @var{num}. If the string begins with @samp{*}, then @code{assemble_name} will @@ -6797,9 +6851,9 @@ string doesn't start with @samp{*}, then @code{ASM_OUTPUT_LABELREF} gets to output the string, and may change it. (Of course, @code{ASM_OUTPUT_LABELREF} is also part of your machine description, so you should know what it does on your machine.) +@end defmac -@findex ASM_FORMAT_PRIVATE_NAME -@item ASM_FORMAT_PRIVATE_NAME (@var{outvar}, @var{name}, @var{number}) +@defmac ASM_FORMAT_PRIVATE_NAME (@var{outvar}, @var{name}, @var{number}) A C expression to assign to @var{outvar} (which is a variable of type @code{char *}) a newly allocated string made from the string @var{name} and the number @var{number}, with some suitable punctuation @@ -6817,17 +6871,20 @@ conflict with the user's own symbols. Most assemblers allow periods or percent signs in assembler symbols; putting at least one of these between the name and the number will suffice. -@findex ASM_OUTPUT_DEF -@item ASM_OUTPUT_DEF (@var{stream}, @var{name}, @var{value}) +If this macro is not defined, a default definition will be provided +which is correct for most systems. +@end defmac + +@defmac ASM_OUTPUT_DEF (@var{stream}, @var{name}, @var{value}) A C statement to output to the stdio stream @var{stream} assembler code which defines (equates) the symbol @var{name} to have the value @var{value}. @findex SET_ASM_OP If @code{SET_ASM_OP} is defined, a default definition is provided which is correct for most systems. +@end defmac -@findex ASM_OUTPUT_DEF_FROM_DECLS -@item ASM_OUTPUT_DEF_FROM_DECLS (@var{stream}, @var{decl_of_name}, @var{decl_of_value}) +@defmac ASM_OUTPUT_DEF_FROM_DECLS (@var{stream}, @var{decl_of_name}, @var{decl_of_value}) A C statement to output to the stdio stream @var{stream} assembler code which defines (equates) the symbol whose tree node is @var{decl_of_name} to have the value of the tree node @var{decl_of_value}. This macro will @@ -6837,9 +6894,9 @@ the tree nodes are available. @findex SET_ASM_OP If @code{SET_ASM_OP} is defined, a default definition is provided which is correct for most systems. +@end defmac -@findex ASM_OUTPUT_WEAK_ALIAS -@item ASM_OUTPUT_WEAK_ALIAS (@var{stream}, @var{name}, @var{value}) +@defmac ASM_OUTPUT_WEAK_ALIAS (@var{stream}, @var{name}, @var{value}) A C statement to output to the stdio stream @var{stream} assembler code which defines (equates) the weak symbol @var{name} to have the value @var{value}. If @var{value} is @code{NULL}, it defines @var{name} as @@ -6847,9 +6904,9 @@ an undefined weak symbol. Define this macro if the target only supports weak aliases; define @code{ASM_OUTPUT_DEF} instead if possible. +@end defmac -@findex OBJC_GEN_METHOD_LABEL -@item OBJC_GEN_METHOD_LABEL (@var{buf}, @var{is_inst}, @var{class_name}, @var{cat_name}, @var{sel_name}) +@defmac OBJC_GEN_METHOD_LABEL (@var{buf}, @var{is_inst}, @var{class_name}, @var{cat_name}, @var{sel_name}) Define this macro to override the default assembler names used for Objective-C methods. @@ -6874,21 +6931,21 @@ in a category); and @var{sel_name} is the name of the selector. On systems where the assembler can handle quoted names, you can use this macro to provide more human-readable names. +@end defmac -@findex ASM_DECLARE_CLASS_REFERENCE -@item ASM_DECLARE_CLASS_REFERENCE (@var{stream}, @var{name}) +@defmac ASM_DECLARE_CLASS_REFERENCE (@var{stream}, @var{name}) A C statement (sans semicolon) to output to the stdio stream @var{stream} commands to declare that the label @var{name} is an Objective-C class reference. This is only needed for targets whose linkers have special support for NeXT-style runtimes. +@end defmac -@findex ASM_DECLARE_UNRESOLVED_REFERENCE -@item ASM_DECLARE_UNRESOLVED_REFERENCE (@var{stream}, @var{name}) +@defmac ASM_DECLARE_UNRESOLVED_REFERENCE (@var{stream}, @var{name}) A C statement (sans semicolon) to output to the stdio stream @var{stream} commands to declare that the label @var{name} is an unresolved Objective-C class reference. This is only needed for targets whose linkers have special support for NeXT-style runtimes. -@end table +@end defmac @node Initialization @subsection How Initialization Functions Are Handled @@ -6954,9 +7011,9 @@ support a @dfn{.init} section which is executed at program startup, parts of @file{crtstuff.c} are compiled into that section. The program is linked by the @command{gcc} driver like this: -@example +@smallexample ld -o @var{output_file} crti.o crtbegin.o @dots{} -lgcc crtend.o crtn.o -@end example +@end smallexample The prologue of a function (@code{__init}) appears in the @code{.init} section of @file{crti.o}; the epilogue appears in @file{crtn.o}. Likewise @@ -7019,34 +7076,33 @@ customize the handling of initialization and termination functions. Here are the macros that control how the compiler handles initialization and termination functions: -@table @code -@findex INIT_SECTION_ASM_OP -@item INIT_SECTION_ASM_OP +@defmac INIT_SECTION_ASM_OP If defined, a C string constant, including spacing, for the assembler operation to identify the following data as initialization code. If not defined, GCC will assume such a section does not exist. When you are using special sections for initialization and termination functions, this macro also controls how @file{crtstuff.c} and @file{libgcc2.c} arrange to run the initialization functions. +@end defmac -@item HAS_INIT_SECTION -@findex HAS_INIT_SECTION +@defmac HAS_INIT_SECTION If defined, @code{main} will not call @code{__main} as described above. This macro should be defined for systems that control start-up code on a symbol-by-symbol basis, such as OSF/1, and should not be defined explicitly for systems that support @code{INIT_SECTION_ASM_OP}. +@end defmac -@item LD_INIT_SWITCH -@findex LD_INIT_SWITCH +@defmac LD_INIT_SWITCH If defined, a C string constant for a switch that tells the linker that the following symbol is an initialization routine. +@end defmac -@item LD_FINI_SWITCH -@findex LD_FINI_SWITCH +@defmac LD_FINI_SWITCH If defined, a C string constant for a switch that tells the linker that the following symbol is a finalization routine. +@end defmac -@item COLLECT_SHARED_INIT_FUNC (@var{stream}, @var{func}) +@defmac COLLECT_SHARED_INIT_FUNC (@var{stream}, @var{func}) If defined, a C statement that will write a function that can be automatically called when a shared library is loaded. The function should call @var{func}, which takes no arguments. If not defined, and @@ -7056,28 +7112,29 @@ function called @code{_GLOBAL__DI} will be generated. This function and the following one are used by collect2 when linking a shared library that needs constructors or destructors, or has DWARF2 exception tables embedded in the code. +@end defmac -@item COLLECT_SHARED_FINI_FUNC (@var{stream}, @var{func}) +@defmac COLLECT_SHARED_FINI_FUNC (@var{stream}, @var{func}) If defined, a C statement that will write a function that can be automatically called when a shared library is unloaded. The function should call @var{func}, which takes no arguments. If not defined, and the object format requires an explicit finalization function, then a function called @code{_GLOBAL__DD} will be generated. +@end defmac -@item INVOKE__main -@findex INVOKE__main +@defmac INVOKE__main If defined, @code{main} will call @code{__main} despite the presence of @code{INIT_SECTION_ASM_OP}. This macro should be defined for systems where the init section is not actually run automatically, but is still useful for collecting the lists of constructors and destructors. +@end defmac -@item SUPPORTS_INIT_PRIORITY -@findex SUPPORTS_INIT_PRIORITY +@defmac SUPPORTS_INIT_PRIORITY If nonzero, the C++ @code{init_priority} attribute is supported and the compiler should emit instructions to control the order of initialization of objects. If zero, the compiler will issue an error message upon encountering an @code{init_priority} attribute. -@end table +@end defmac @deftypefn {Target Hook} bool TARGET_HAVE_CTORS_DTORS This value is true if the target supports some ``native'' method of @@ -7112,27 +7169,25 @@ If your system uses @command{collect2} as the means of processing constructors, then that program normally uses @command{nm} to scan an object file for constructor functions to be called. -On certain kinds of systems, you can define these macros to make +On certain kinds of systems, you can define this macro to make @command{collect2} work faster (and, in some cases, make it work at all): -@table @code -@findex OBJECT_FORMAT_COFF -@item OBJECT_FORMAT_COFF +@defmac OBJECT_FORMAT_COFF Define this macro if the system uses COFF (Common Object File Format) object files, so that @command{collect2} can assume this format and scan object files directly for dynamic constructor/destructor functions. -@findex OBJECT_FORMAT_ROSE -@item OBJECT_FORMAT_ROSE -Define this macro if the system uses ROSE format object files, so that -@command{collect2} can assume this format and scan object files directly -for dynamic constructor/destructor functions. - -These macros are effective only in a native compiler; @command{collect2} as +This macro is effective only in a native compiler; @command{collect2} as part of a cross compiler always uses @command{nm} for the target machine. +@end defmac + +@defmac COLLECT_PARSE_FLAG (@var{flag}) +Define this macro to be C code that examines @command{collect2} command +line option @var{flag} and performs special actions if +@command{collect2} needs to behave differently depending on @var{flag}. +@end defmac -@findex REAL_NM_FILE_NAME -@item REAL_NM_FILE_NAME +@defmac REAL_NM_FILE_NAME Define this macro as a C string constant containing the file name to use to execute @command{nm}. The default is to search the path normally for @command{nm}. @@ -7141,21 +7196,21 @@ If your system supports shared libraries and has a program to list the dynamic dependencies of a given library or executable, you can define these macros to enable support for running initialization and termination functions in shared libraries: +@end defmac -@findex LDD_SUFFIX -@item LDD_SUFFIX +@defmac LDD_SUFFIX Define this macro to a C string constant containing the name of the program which lists dynamic dependencies, like @command{"ldd"} under SunOS 4. +@end defmac -@findex PARSE_LDD_OUTPUT -@item PARSE_LDD_OUTPUT (@var{ptr}) +@defmac PARSE_LDD_OUTPUT (@var{ptr}) Define this macro to be C code that extracts filenames from the output of the program denoted by @code{LDD_SUFFIX}. @var{ptr} is a variable of type @code{char *} that points to the beginning of a line of output from @code{LDD_SUFFIX}. If the line lists a dynamic dependency, the code must advance @var{ptr} to the beginning of the filename on that line. Otherwise, it must set @var{ptr} to @code{NULL}. -@end table +@end defmac @node Instruction Output @subsection Output of Assembler Instructions @@ -7163,22 +7218,20 @@ line. Otherwise, it must set @var{ptr} to @code{NULL}. @c prevent bad page break with this line This describes assembler instruction output. -@table @code -@findex REGISTER_NAMES -@item REGISTER_NAMES +@defmac REGISTER_NAMES A C initializer containing the assembler's names for the machine registers, each one as a C string constant. This is what translates register numbers in the compiler into assembler language. +@end defmac -@findex ADDITIONAL_REGISTER_NAMES -@item ADDITIONAL_REGISTER_NAMES +@defmac ADDITIONAL_REGISTER_NAMES If defined, a C initializer for an array of structures containing a name and a register number. This macro defines additional names for hard registers, thus allowing the @code{asm} option in declarations to refer to registers using alternate names. +@end defmac -@findex ASM_OUTPUT_OPCODE -@item ASM_OUTPUT_OPCODE (@var{stream}, @var{ptr}) +@defmac ASM_OUTPUT_OPCODE (@var{stream}, @var{ptr}) Define this macro if you are using an unusual assembler that requires different names for the machine instructions. @@ -7203,9 +7256,9 @@ elements of @code{recog_data.operand}. If the macro definition does nothing, the instruction is output in the usual way. +@end defmac -@findex FINAL_PRESCAN_INSN -@item FINAL_PRESCAN_INSN (@var{insn}, @var{opvec}, @var{noperands}) +@defmac FINAL_PRESCAN_INSN (@var{insn}, @var{opvec}, @var{noperands}) If defined, a C statement to be executed just prior to the output of assembler code for @var{insn}, to modify the extracted operands so they will be output differently. @@ -7225,15 +7278,9 @@ syntax affecting individual insn patterns ought to be handled by writing conditional output routines in those patterns. If this macro is not defined, it is equivalent to a null statement. +@end defmac -@findex FINAL_PRESCAN_LABEL -@item FINAL_PRESCAN_LABEL -If defined, @code{FINAL_PRESCAN_INSN} will be called on each -@code{CODE_LABEL}. In that case, @var{opvec} will be a null pointer and -@var{noperands} will be zero. - -@findex PRINT_OPERAND -@item PRINT_OPERAND (@var{stream}, @var{x}, @var{code}) +@defmac PRINT_OPERAND (@var{stream}, @var{x}, @var{code}) A C compound statement to output to stdio stream @var{stream} the assembler syntax for an instruction operand @var{x}. @var{x} is an RTL expression. @@ -7256,17 +7303,17 @@ When the machine description has a specification @samp{%@var{punct}} (a @samp{%} followed by a punctuation character), this macro is called with a null pointer for @var{x} and the punctuation character for @var{code}. +@end defmac -@findex PRINT_OPERAND_PUNCT_VALID_P -@item PRINT_OPERAND_PUNCT_VALID_P (@var{code}) +@defmac PRINT_OPERAND_PUNCT_VALID_P (@var{code}) A C expression which evaluates to true if @var{code} is a valid punctuation character for use in the @code{PRINT_OPERAND} macro. If @code{PRINT_OPERAND_PUNCT_VALID_P} is not defined, it means that no punctuation characters (except for the standard one, @samp{%}) are used in this way. +@end defmac -@findex PRINT_OPERAND_ADDRESS -@item PRINT_OPERAND_ADDRESS (@var{stream}, @var{x}) +@defmac PRINT_OPERAND_ADDRESS (@var{stream}, @var{x}) A C compound statement to output to stdio stream @var{stream} the assembler syntax for an instruction operand that is a memory reference whose address is @var{x}. @var{x} is an RTL expression. @@ -7275,11 +7322,12 @@ whose address is @var{x}. @var{x} is an RTL expression. On some machines, the syntax for a symbolic address depends on the section that the address refers to. On these machines, define the hook @code{TARGET_ENCODE_SECTION_INFO} to store the information into the -@code{symbol_ref}, and then check for it here. @xref{Assembler Format}. +@code{symbol_ref}, and then check for it here. @xref{Assembler +Format}. +@end defmac -@findex DBR_OUTPUT_SEQEND @findex dbr_sequence_length -@item DBR_OUTPUT_SEQEND(@var{file}) +@defmac DBR_OUTPUT_SEQEND (@var{file}) A C statement, to be executed after all slot-filler instructions have been output. If necessary, call @code{dbr_sequence_length} to determine the number of slots filled in a sequence (zero if not @@ -7289,6 +7337,7 @@ or whatever. Don't define this macro if it has nothing to do, but it is helpful in reading assembly output if the extent of the delay sequence is made explicit (e.g.@: with white space). +@end defmac @findex final_sequence Note that output routines for instructions with delay slots must be @@ -7298,36 +7347,32 @@ found.) The variable @code{final_sequence} is null when not processing a sequence, otherwise it contains the @code{sequence} rtx being output. -@findex REGISTER_PREFIX -@findex LOCAL_LABEL_PREFIX -@findex USER_LABEL_PREFIX -@findex IMMEDIATE_PREFIX @findex asm_fprintf -@item REGISTER_PREFIX -@itemx LOCAL_LABEL_PREFIX -@itemx USER_LABEL_PREFIX -@itemx IMMEDIATE_PREFIX +@defmac REGISTER_PREFIX +@defmacx LOCAL_LABEL_PREFIX +@defmacx USER_LABEL_PREFIX +@defmacx IMMEDIATE_PREFIX If defined, C string expressions to be used for the @samp{%R}, @samp{%L}, @samp{%U}, and @samp{%I} options of @code{asm_fprintf} (see @file{final.c}). These are useful when a single @file{md} file must support multiple assembler formats. In that case, the various @file{tm.h} files can define these macros differently. +@end defmac -@item ASM_FPRINTF_EXTENSIONS(@var{file}, @var{argptr}, @var{format}) -@findex ASM_FPRINTF_EXTENSIONS +@defmac ASM_FPRINTF_EXTENSIONS (@var{file}, @var{argptr}, @var{format}) If defined this macro should expand to a series of @code{case} statements which will be parsed inside the @code{switch} statement of the @code{asm_fprintf} function. This allows targets to define extra printf formats which may useful when generating their assembler -statements. Note that upper case letters are reserved for future +statements. Note that uppercase letters are reserved for future generic extensions to asm_fprintf, and so are not available to target specific code. The output file is given by the parameter @var{file}. The varargs input pointer is @var{argptr} and the rest of the format string, starting the character after the one that is being switched upon, is pointed to by @var{format}. +@end defmac -@findex ASSEMBLER_DIALECT -@item ASSEMBLER_DIALECT +@defmac ASSEMBLER_DIALECT If your target supports multiple dialects of assembler language (such as different opcodes), define this macro as a C expression that gives the numeric index of the assembler language dialect to use, with zero as the @@ -7356,21 +7401,21 @@ the variations in assembler language syntax with that mechanism. Define @code{ASSEMBLER_DIALECT} and use the @samp{@{option0|option1@}} syntax if the syntax variant are larger and involve such things as different opcodes or operand order. +@end defmac -@findex ASM_OUTPUT_REG_PUSH -@item ASM_OUTPUT_REG_PUSH (@var{stream}, @var{regno}) +@defmac ASM_OUTPUT_REG_PUSH (@var{stream}, @var{regno}) A C expression to output to @var{stream} some assembler code which will push hard register number @var{regno} onto the stack. The code need not be optimal, since this macro is used only when profiling. +@end defmac -@findex ASM_OUTPUT_REG_POP -@item ASM_OUTPUT_REG_POP (@var{stream}, @var{regno}) +@defmac ASM_OUTPUT_REG_POP (@var{stream}, @var{regno}) A C expression to output to @var{stream} some assembler code which will pop hard register number @var{regno} off of the stack. The code need not be optimal, since this macro is used only when profiling. -@end table +@end defmac @node Dispatch Tables @subsection Output of Dispatch Tables @@ -7378,48 +7423,46 @@ profiling. @c prevent bad page break with this line This concerns dispatch tables. -@table @code @cindex dispatch table -@findex ASM_OUTPUT_ADDR_DIFF_ELT -@item ASM_OUTPUT_ADDR_DIFF_ELT (@var{stream}, @var{body}, @var{value}, @var{rel}) +@defmac ASM_OUTPUT_ADDR_DIFF_ELT (@var{stream}, @var{body}, @var{value}, @var{rel}) A C statement to output to the stdio stream @var{stream} an assembler pseudo-instruction to generate a difference between two labels. @var{value} and @var{rel} are the numbers of two internal labels. The definitions of these labels are output using -@code{ASM_OUTPUT_INTERNAL_LABEL}, and they must be printed in the same +@code{(*targetm.asm_out.internal_label)}, and they must be printed in the same way here. For example, -@example +@smallexample fprintf (@var{stream}, "\t.word L%d-L%d\n", @var{value}, @var{rel}) -@end example +@end smallexample You must provide this macro on machines where the addresses in a dispatch table are relative to the table's own address. If defined, GCC will also use this macro on all machines when producing PIC@. @var{body} is the body of the @code{ADDR_DIFF_VEC}; it is provided so that the mode and flags can be read. +@end defmac -@findex ASM_OUTPUT_ADDR_VEC_ELT -@item ASM_OUTPUT_ADDR_VEC_ELT (@var{stream}, @var{value}) +@defmac ASM_OUTPUT_ADDR_VEC_ELT (@var{stream}, @var{value}) This macro should be provided on machines where the addresses in a dispatch table are absolute. The definition should be a C statement to output to the stdio stream @var{stream} an assembler pseudo-instruction to generate a reference to a label. @var{value} is the number of an internal label whose -definition is output using @code{ASM_OUTPUT_INTERNAL_LABEL}. +definition is output using @code{(*targetm.asm_out.internal_label)}. For example, -@example +@smallexample fprintf (@var{stream}, "\t.word L%d\n", @var{value}) -@end example +@end smallexample +@end defmac -@findex ASM_OUTPUT_CASE_LABEL -@item ASM_OUTPUT_CASE_LABEL (@var{stream}, @var{prefix}, @var{num}, @var{table}) +@defmac ASM_OUTPUT_CASE_LABEL (@var{stream}, @var{prefix}, @var{num}, @var{table}) Define this if the label before a jump-table needs to be output specially. The first three arguments are the same as for -@code{ASM_OUTPUT_INTERNAL_LABEL}; the fourth argument is the +@code{(*targetm.asm_out.internal_label)}; the fourth argument is the jump-table which follows (a @code{jump_insn} containing an @code{addr_vec} or @code{addr_diff_vec}). @@ -7427,10 +7470,10 @@ This feature is used on system V to output a @code{swbeg} statement for the table. If this macro is not defined, these labels are output with -@code{ASM_OUTPUT_INTERNAL_LABEL}. +@code{(*targetm.asm_out.internal_label)}. +@end defmac -@findex ASM_OUTPUT_CASE_END -@item ASM_OUTPUT_CASE_END (@var{stream}, @var{num}, @var{table}) +@defmac ASM_OUTPUT_CASE_END (@var{stream}, @var{num}, @var{table}) Define this if something special must be output at the end of a jump-table. The definition should be a C statement to be executed after the assembler code for the table is written. It should write @@ -7440,7 +7483,7 @@ of the preceding label. If this macro is not defined, nothing special is output at the end of the jump-table. -@end table +@end defmac @node Exception Region Output @subsection Assembler Commands for Exception Regions @@ -7450,9 +7493,7 @@ the jump-table. This describes commands marking the start and the end of an exception region. -@table @code -@findex EH_FRAME_SECTION_NAME -@item EH_FRAME_SECTION_NAME +@defmac EH_FRAME_SECTION_NAME If defined, a C string constant for the name of the section containing exception handling frame unwind information. If not defined, GCC will provide a default definition if the target supports named sections. @@ -7460,9 +7501,9 @@ provide a default definition if the target supports named sections. You should define this symbol if your target supports DWARF 2 frame unwind information and the default definition does not work. +@end defmac -@findex EH_FRAME_IN_DATA_SECTION -@item EH_FRAME_IN_DATA_SECTION +@defmac EH_FRAME_IN_DATA_SECTION If defined, DWARF 2 frame unwind information will be placed in the data section even though the target supports named sections. This might be necessary, for instance, if the system linker does garbage @@ -7470,14 +7511,14 @@ collection and sections cannot be marked as not to be collected. Do not define this macro unless @code{TARGET_ASM_NAMED_SECTION} is also defined. +@end defmac -@findex MASK_RETURN_ADDR -@item MASK_RETURN_ADDR +@defmac MASK_RETURN_ADDR An rtx used to mask the return address found via @code{RETURN_ADDR_RTX}, so that it does not contain any extraneous set bits in it. +@end defmac -@findex DWARF2_UNWIND_INFO -@item DWARF2_UNWIND_INFO +@defmac DWARF2_UNWIND_INFO Define this macro to 0 if your target supports DWARF 2 frame unwind information, but it does not yet work with exception handling. Otherwise, if your target supports this information (if it defines @@ -7491,17 +7532,23 @@ default. If this macro is defined to anything, the DWARF 2 unwinder will be used instead of inline unwinders and @code{__unwind_function} in the non-@code{setjmp} case. +@end defmac + +@defmac MUST_USE_SJLJ_EXCEPTIONS +This macro need only be defined if @code{DWARF2_UNWIND_INFO} is +runtime-variable. In that case, @file{except.h} cannot correctly +determine the corresponding definition of +@code{MUST_USE_SJLJ_EXCEPTIONS}, so the target must provide it directly. +@end defmac -@findex DWARF_CIE_DATA_ALIGNMENT -@item DWARF_CIE_DATA_ALIGNMENT +@defmac DWARF_CIE_DATA_ALIGNMENT This macro need only be defined if the target might save registers in the function prologue at an offset to the stack pointer that is not aligned to @code{UNITS_PER_WORD}. The definition should be the negative minimum alignment if @code{STACK_GROWS_DOWNWARD} is defined, and the positive minimum alignment otherwise. @xref{SDB and DWARF}. Only applicable if the target supports DWARF 2 frame unwind information. - -@end table +@end defmac @deftypefn {Target Hook} void TARGET_ASM_EXCEPTION_SECTION () If defined, a function that switches to the section in which the main @@ -7528,15 +7575,22 @@ Default value is false if @code{EH_FRAME_SECTION_NAME} is defined, and true otherwise. @end deftypevar +@deftypefn {Target Hook} rtx TARGET_DWARF_REGISTER_SPAN (rtx @var{reg}) +Given a register, this hook should return a parallel of registers to +represent where to find the register pieces. Define this hook if the +register and its mode are represented in Dwarf in non-contiguous +locations, or if the register should be represented in more than one +register in Dwarf. Otherwise, this hook should return @code{NULL_RTX}. +If not defined, the default is to return @code{NULL_RTX}. +@end deftypefn + @node Alignment Output @subsection Assembler Commands for Alignment @c prevent bad page break with this line This describes commands for alignment. -@table @code -@findex JUMP_ALIGN -@item JUMP_ALIGN (@var{label}) +@defmac JUMP_ALIGN (@var{label}) The alignment (log base 2) to put in front of @var{label}, which is a common destination of jumps and has no fallthru incoming edge. @@ -7548,24 +7602,24 @@ Unless it's necessary to inspect the @var{label} parameter, it is better to set the variable @var{align_jumps} in the target's @code{OVERRIDE_OPTIONS}. Otherwise, you should try to honor the user's selection in @var{align_jumps} in a @code{JUMP_ALIGN} implementation. +@end defmac -@findex LABEL_ALIGN_AFTER_BARRIER -@item LABEL_ALIGN_AFTER_BARRIER (@var{label}) +@defmac LABEL_ALIGN_AFTER_BARRIER (@var{label}) The alignment (log base 2) to put in front of @var{label}, which follows a @code{BARRIER}. This macro need not be defined if you don't want any special alignment to be done at such a time. Most machine descriptions do not currently define the macro. +@end defmac -@findex LABEL_ALIGN_AFTER_BARRIER_MAX_SKIP -@item LABEL_ALIGN_AFTER_BARRIER_MAX_SKIP +@defmac LABEL_ALIGN_AFTER_BARRIER_MAX_SKIP The maximum number of bytes to skip when applying @code{LABEL_ALIGN_AFTER_BARRIER}. This works only if @code{ASM_OUTPUT_MAX_SKIP_ALIGN} is defined. +@end defmac -@findex LOOP_ALIGN -@item LOOP_ALIGN (@var{label}) +@defmac LOOP_ALIGN (@var{label}) The alignment (log base 2) to put in front of @var{label}, which follows a @code{NOTE_INSN_LOOP_BEG} note. @@ -7577,14 +7631,14 @@ Unless it's necessary to inspect the @var{label} parameter, it is better to set the variable @code{align_loops} in the target's @code{OVERRIDE_OPTIONS}. Otherwise, you should try to honor the user's selection in @code{align_loops} in a @code{LOOP_ALIGN} implementation. +@end defmac -@findex LOOP_ALIGN_MAX_SKIP -@item LOOP_ALIGN_MAX_SKIP +@defmac LOOP_ALIGN_MAX_SKIP The maximum number of bytes to skip when applying @code{LOOP_ALIGN}. This works only if @code{ASM_OUTPUT_MAX_SKIP_ALIGN} is defined. +@end defmac -@findex LABEL_ALIGN -@item LABEL_ALIGN (@var{label}) +@defmac LABEL_ALIGN (@var{label}) The alignment (log base 2) to put in front of @var{label}. If @code{LABEL_ALIGN_AFTER_BARRIER} / @code{LOOP_ALIGN} specify a different alignment, the maximum of the specified values is used. @@ -7593,46 +7647,46 @@ Unless it's necessary to inspect the @var{label} parameter, it is better to set the variable @code{align_labels} in the target's @code{OVERRIDE_OPTIONS}. Otherwise, you should try to honor the user's selection in @code{align_labels} in a @code{LABEL_ALIGN} implementation. +@end defmac -@findex LABEL_ALIGN_MAX_SKIP -@item LABEL_ALIGN_MAX_SKIP +@defmac LABEL_ALIGN_MAX_SKIP The maximum number of bytes to skip when applying @code{LABEL_ALIGN}. This works only if @code{ASM_OUTPUT_MAX_SKIP_ALIGN} is defined. +@end defmac -@findex ASM_OUTPUT_SKIP -@item ASM_OUTPUT_SKIP (@var{stream}, @var{nbytes}) +@defmac ASM_OUTPUT_SKIP (@var{stream}, @var{nbytes}) A C statement to output to the stdio stream @var{stream} an assembler instruction to advance the location counter by @var{nbytes} bytes. Those bytes should be zero when loaded. @var{nbytes} will be a C expression of type @code{int}. +@end defmac -@findex ASM_NO_SKIP_IN_TEXT -@item ASM_NO_SKIP_IN_TEXT +@defmac ASM_NO_SKIP_IN_TEXT Define this macro if @code{ASM_OUTPUT_SKIP} should not be used in the text section because it fails to put zeros in the bytes that are skipped. This is true on many Unix systems, where the pseudo--op to skip bytes produces no-op instructions rather than zeros when used in the text section. +@end defmac -@findex ASM_OUTPUT_ALIGN -@item ASM_OUTPUT_ALIGN (@var{stream}, @var{power}) +@defmac ASM_OUTPUT_ALIGN (@var{stream}, @var{power}) A C statement to output to the stdio stream @var{stream} an assembler command to advance the location counter to a multiple of 2 to the @var{power} bytes. @var{power} will be a C expression of type @code{int}. +@end defmac -@findex ASM_OUTPUT_ALIGN_WITH_NOP -@item ASM_OUTPUT_ALIGN_WITH_NOP (@var{stream}, @var{power}) +@defmac ASM_OUTPUT_ALIGN_WITH_NOP (@var{stream}, @var{power}) Like @code{ASM_OUTPUT_ALIGN}, except that the ``nop'' instruction is used for padding, if necessary. +@end defmac -@findex ASM_OUTPUT_MAX_SKIP_ALIGN -@item ASM_OUTPUT_MAX_SKIP_ALIGN (@var{stream}, @var{power}, @var{max_skip}) +@defmac ASM_OUTPUT_MAX_SKIP_ALIGN (@var{stream}, @var{power}, @var{max_skip}) A C statement to output to the stdio stream @var{stream} an assembler command to advance the location counter to a multiple of 2 to the @var{power} bytes, but only if @var{max_skip} or fewer bytes are needed to satisfy the alignment request. @var{power} and @var{max_skip} will be a C expression of type @code{int}. -@end table +@end defmac @need 3000 @node Debugging Info @@ -7656,9 +7710,7 @@ This describes how to specify debugging information. @c prevent bad page break with this line These macros affect all debugging formats. -@table @code -@findex DBX_REGISTER_NUMBER -@item DBX_REGISTER_NUMBER (@var{regno}) +@defmac DBX_REGISTER_NUMBER (@var{regno}) A C expression that returns the DBX register number for the compiler register number @var{regno}. In the default macro provided, the value of this expression will be @var{regno} itself. But sometimes there are @@ -7675,9 +7727,9 @@ expect register pairs to be consecutive in their own numbering scheme. If you find yourself defining @code{DBX_REGISTER_NUMBER} in way that does not preserve register pairs, then what you must do instead is redefine the actual register numbering scheme. +@end defmac -@findex DEBUGGER_AUTO_OFFSET -@item DEBUGGER_AUTO_OFFSET (@var{x}) +@defmac DEBUGGER_AUTO_OFFSET (@var{x}) A C expression that returns the integer offset value for an automatic variable having address @var{x} (an RTL expression). The default computation assumes that @var{x} is based on the frame-pointer and @@ -7685,15 +7737,15 @@ gives the offset from the frame-pointer. This is required for targets that produce debugging output for DBX or COFF-style debugging output for SDB and allow the frame-pointer to be eliminated when the @option{-g} options is used. +@end defmac -@findex DEBUGGER_ARG_OFFSET -@item DEBUGGER_ARG_OFFSET (@var{offset}, @var{x}) +@defmac DEBUGGER_ARG_OFFSET (@var{offset}, @var{x}) A C expression that returns the integer offset value for an argument having address @var{x} (an RTL expression). The nominal offset is @var{offset}. +@end defmac -@findex PREFERRED_DEBUGGING_TYPE -@item PREFERRED_DEBUGGING_TYPE +@defmac PREFERRED_DEBUGGING_TYPE A C expression that returns the type of debugging output GCC should produce when the user specifies just @option{-g}. Define this if you have arranged for GCC to support more than one format of @@ -7703,16 +7755,14 @@ debugging output. Currently, the allowable values are @code{DBX_DEBUG}, When the user specifies @option{-ggdb}, GCC normally also uses the value of this macro to select the debugging output format, but with two -exceptions. If @code{DWARF2_DEBUGGING_INFO} is defined and -@code{LINKER_DOES_NOT_WORK_WITH_DWARF2} is not defined, GCC uses the +exceptions. If @code{DWARF2_DEBUGGING_INFO} is defined, GCC uses the value @code{DWARF2_DEBUG}. Otherwise, if @code{DBX_DEBUGGING_INFO} is defined, GCC uses @code{DBX_DEBUG}. The value of this macro only affects the default debugging output; the user can always get a specific type of output by using @option{-gstabs}, -@option{-gcoff}, @option{-gdwarf-1}, @option{-gdwarf-2}, @option{-gxcoff}, -or @option{-gvms}. -@end table +@option{-gcoff}, @option{-gdwarf-2}, @option{-gxcoff}, or @option{-gvms}. +@end defmac @node DBX Options @subsection Specific Options for DBX Output @@ -7720,61 +7770,59 @@ or @option{-gvms}. @c prevent bad page break with this line These are specific options for DBX output. -@table @code -@findex DBX_DEBUGGING_INFO -@item DBX_DEBUGGING_INFO +@defmac DBX_DEBUGGING_INFO Define this macro if GCC should produce debugging output for DBX in response to the @option{-g} option. +@end defmac -@findex XCOFF_DEBUGGING_INFO -@item XCOFF_DEBUGGING_INFO +@defmac XCOFF_DEBUGGING_INFO Define this macro if GCC should produce XCOFF format debugging output in response to the @option{-g} option. This is a variant of DBX format. +@end defmac -@findex DEFAULT_GDB_EXTENSIONS -@item DEFAULT_GDB_EXTENSIONS +@defmac DEFAULT_GDB_EXTENSIONS Define this macro to control whether GCC should by default generate GDB's extended version of DBX debugging information (assuming DBX-format debugging information is enabled at all). If you don't define the macro, the default is 1: always generate the extended information if there is any occasion to. +@end defmac -@findex DEBUG_SYMS_TEXT -@item DEBUG_SYMS_TEXT +@defmac DEBUG_SYMS_TEXT Define this macro if all @code{.stabs} commands should be output while in the text section. +@end defmac -@findex ASM_STABS_OP -@item ASM_STABS_OP +@defmac ASM_STABS_OP A C string constant, including spacing, naming the assembler pseudo op to use instead of @code{"\t.stabs\t"} to define an ordinary debugging symbol. If you don't define this macro, @code{"\t.stabs\t"} is used. This macro applies only to DBX debugging information format. +@end defmac -@findex ASM_STABD_OP -@item ASM_STABD_OP +@defmac ASM_STABD_OP A C string constant, including spacing, naming the assembler pseudo op to use instead of @code{"\t.stabd\t"} to define a debugging symbol whose value is the current location. If you don't define this macro, @code{"\t.stabd\t"} is used. This macro applies only to DBX debugging information format. +@end defmac -@findex ASM_STABN_OP -@item ASM_STABN_OP +@defmac ASM_STABN_OP A C string constant, including spacing, naming the assembler pseudo op to use instead of @code{"\t.stabn\t"} to define a debugging symbol with no name. If you don't define this macro, @code{"\t.stabn\t"} is used. This macro applies only to DBX debugging information format. +@end defmac -@findex DBX_NO_XREFS -@item DBX_NO_XREFS +@defmac DBX_NO_XREFS Define this macro if DBX on your system does not support the construct @samp{xs@var{tagname}}. On some systems, this construct is used to describe a forward reference to a structure named @var{tagname}. On other systems, this construct is not supported at all. +@end defmac -@findex DBX_CONTIN_LENGTH -@item DBX_CONTIN_LENGTH +@defmac DBX_CONTIN_LENGTH A symbol name in DBX-format debugging information is normally continued (split into two separate @code{.stabs} directives) when it exceeds a certain length (by default, 80 characters). On some @@ -7782,78 +7830,71 @@ operating systems, DBX requires this splitting; on others, splitting must not be done. You can inhibit splitting by defining this macro with the value zero. You can override the default splitting-length by defining this macro as an expression for the length you desire. +@end defmac -@findex DBX_CONTIN_CHAR -@item DBX_CONTIN_CHAR +@defmac DBX_CONTIN_CHAR Normally continuation is indicated by adding a @samp{\} character to the end of a @code{.stabs} string when a continuation follows. To use a different character instead, define this macro as a character constant for the character you want to use. Do not define this macro if backslash is correct for your system. +@end defmac -@findex DBX_STATIC_STAB_DATA_SECTION -@item DBX_STATIC_STAB_DATA_SECTION +@defmac DBX_STATIC_STAB_DATA_SECTION Define this macro if it is necessary to go to the data section before outputting the @samp{.stabs} pseudo-op for a non-global static variable. +@end defmac -@findex DBX_TYPE_DECL_STABS_CODE -@item DBX_TYPE_DECL_STABS_CODE +@defmac DBX_TYPE_DECL_STABS_CODE The value to use in the ``code'' field of the @code{.stabs} directive for a typedef. The default is @code{N_LSYM}. +@end defmac -@findex DBX_STATIC_CONST_VAR_CODE -@item DBX_STATIC_CONST_VAR_CODE +@defmac DBX_STATIC_CONST_VAR_CODE The value to use in the ``code'' field of the @code{.stabs} directive for a static variable located in the text section. DBX format does not provide any ``right'' way to do this. The default is @code{N_FUN}. +@end defmac -@findex DBX_REGPARM_STABS_CODE -@item DBX_REGPARM_STABS_CODE +@defmac DBX_REGPARM_STABS_CODE The value to use in the ``code'' field of the @code{.stabs} directive for a parameter passed in registers. DBX format does not provide any ``right'' way to do this. The default is @code{N_RSYM}. +@end defmac -@findex DBX_REGPARM_STABS_LETTER -@item DBX_REGPARM_STABS_LETTER +@defmac DBX_REGPARM_STABS_LETTER The letter to use in DBX symbol data to identify a symbol as a parameter passed in registers. DBX format does not customarily provide any way to do this. The default is @code{'P'}. +@end defmac -@findex DBX_MEMPARM_STABS_LETTER -@item DBX_MEMPARM_STABS_LETTER +@defmac DBX_MEMPARM_STABS_LETTER The letter to use in DBX symbol data to identify a symbol as a stack parameter. The default is @code{'p'}. +@end defmac -@findex DBX_FUNCTION_FIRST -@item DBX_FUNCTION_FIRST +@defmac DBX_FUNCTION_FIRST Define this macro if the DBX information for a function and its arguments should precede the assembler code for the function. Normally, in DBX format, the debugging information entirely follows the assembler code. +@end defmac -@findex DBX_LBRAC_FIRST -@item DBX_LBRAC_FIRST -Define this macro if the @code{N_LBRAC} symbol for a block should -precede the debugging information for variables and functions defined in -that block. Normally, in DBX format, the @code{N_LBRAC} symbol comes -first. - -@findex DBX_BLOCKS_FUNCTION_RELATIVE -@item DBX_BLOCKS_FUNCTION_RELATIVE +@defmac DBX_BLOCKS_FUNCTION_RELATIVE Define this macro if the value of a symbol describing the scope of a block (@code{N_LBRAC} or @code{N_RBRAC}) should be relative to the start of the enclosing function. Normally, GCC uses an absolute address. +@end defmac -@findex DBX_USE_BINCL -@item DBX_USE_BINCL +@defmac DBX_USE_BINCL Define this macro if GCC should generate @code{N_BINCL} and @code{N_EINCL} stabs for included header files, as on Sun systems. This macro also directs GCC to output a type number as a pair of a file number and a type number within the file. Normally, GCC does not generate @code{N_BINCL} or @code{N_EINCL} stabs, and it outputs a single number for a type number. -@end table +@end defmac @node DBX Hooks @subsection Open-Ended Hooks for DBX Format @@ -7861,40 +7902,31 @@ number for a type number. @c prevent bad page break with this line These are hooks for DBX format. -@table @code -@findex DBX_OUTPUT_LBRAC -@item DBX_OUTPUT_LBRAC (@var{stream}, @var{name}) +@defmac DBX_OUTPUT_LBRAC (@var{stream}, @var{name}) Define this macro to say how to output to @var{stream} the debugging information for the start of a scope level for variable names. The argument @var{name} is the name of an assembler symbol (for use with @code{assemble_name}) whose value is the address where the scope begins. +@end defmac -@findex DBX_OUTPUT_RBRAC -@item DBX_OUTPUT_RBRAC (@var{stream}, @var{name}) +@defmac DBX_OUTPUT_RBRAC (@var{stream}, @var{name}) Like @code{DBX_OUTPUT_LBRAC}, but for the end of a scope level. +@end defmac -@findex DBX_OUTPUT_NFUN -@item DBX_OUTPUT_NFUN (@var{stream}, @var{lscope_label}, @var{decl}) +@defmac DBX_OUTPUT_NFUN (@var{stream}, @var{lscope_label}, @var{decl}) Define this macro if the target machine requires special handling to output an @code{N_FUN} entry for the function @var{decl}. +@end defmac -@findex DBX_OUTPUT_ENUM -@item DBX_OUTPUT_ENUM (@var{stream}, @var{type}) -Define this macro if the target machine requires special handling to -output an enumeration type. The definition should be a C statement -(sans semicolon) to output the appropriate information to @var{stream} -for the type @var{type}. - -@findex DBX_OUTPUT_FUNCTION_END -@item DBX_OUTPUT_FUNCTION_END (@var{stream}, @var{function}) +@defmac DBX_OUTPUT_FUNCTION_END (@var{stream}, @var{function}) Define this macro if the target machine requires special output at the end of the debugging information for a function. The definition should be a C statement (sans semicolon) to output the appropriate information to @var{stream}. @var{function} is the @code{FUNCTION_DECL} node for the function. +@end defmac -@findex DBX_OUTPUT_STANDARD_TYPES -@item DBX_OUTPUT_STANDARD_TYPES (@var{syms}) +@defmac DBX_OUTPUT_STANDARD_TYPES (@var{syms}) Define this macro if you need to control the order of output of the standard data types at the beginning of compilation. The argument @var{syms} is a @code{tree} which is a chain of all the predefined @@ -7951,15 +7983,14 @@ Here is another way of finding a particular type: @} @end group @end smallexample +@end defmac -@findex NO_DBX_FUNCTION_END -@item NO_DBX_FUNCTION_END +@defmac NO_DBX_FUNCTION_END Some stabs encapsulation formats (in particular ECOFF), cannot handle the @code{.stabs "",N_FUN,,0,0,Lscope-function-1} gdb dbx extension construct. On those machines, define this macro to turn this feature off without disturbing the rest of the gdb extensions. - -@end table +@end defmac @node File Names and DBX @subsection File Names in DBX Format @@ -7967,17 +7998,7 @@ disturbing the rest of the gdb extensions. @c prevent bad page break with this line This describes file names in DBX format. -@table @code -@findex DBX_WORKING_DIRECTORY -@item DBX_WORKING_DIRECTORY -Define this if DBX wants to have the current directory recorded in each -object file. - -Note that the working directory is always recorded if GDB extensions are -enabled. - -@findex DBX_OUTPUT_MAIN_SOURCE_FILENAME -@item DBX_OUTPUT_MAIN_SOURCE_FILENAME (@var{stream}, @var{name}) +@defmac DBX_OUTPUT_MAIN_SOURCE_FILENAME (@var{stream}, @var{name}) A C statement to output DBX debugging information to the stdio stream @var{stream} which indicates that file @var{name} is the main source file---the file specified as the input file for compilation. @@ -7985,35 +8006,24 @@ This macro is called only once, at the beginning of compilation. This macro need not be defined if the standard form of output for DBX debugging information is appropriate. +@end defmac -@findex DBX_OUTPUT_MAIN_SOURCE_DIRECTORY -@item DBX_OUTPUT_MAIN_SOURCE_DIRECTORY (@var{stream}, @var{name}) +@defmac DBX_OUTPUT_MAIN_SOURCE_DIRECTORY (@var{stream}, @var{name}) A C statement to output DBX debugging information to the stdio stream @var{stream} which indicates that the current directory during compilation is named @var{name}. This macro need not be defined if the standard form of output for DBX debugging information is appropriate. +@end defmac -@findex DBX_OUTPUT_MAIN_SOURCE_FILE_END -@item DBX_OUTPUT_MAIN_SOURCE_FILE_END (@var{stream}, @var{name}) +@defmac DBX_OUTPUT_MAIN_SOURCE_FILE_END (@var{stream}, @var{name}) A C statement to output DBX debugging information at the end of compilation of the main source file @var{name}. If you don't define this macro, nothing special is output at the end of compilation, which is correct for most machines. - -@findex DBX_OUTPUT_SOURCE_FILENAME -@item DBX_OUTPUT_SOURCE_FILENAME (@var{stream}, @var{name}) -A C statement to output DBX debugging information to the stdio stream -@var{stream} which indicates that file @var{name} is the current source -file. This output is generated each time input shifts to a different -source file as a result of @samp{#include}, the end of an included file, -or a @samp{#line} command. - -This macro need not be defined if the standard form of output -for DBX debugging information is appropriate. -@end table +@end defmac @need 2000 @node SDB and DWARF @@ -8022,19 +8032,12 @@ for DBX debugging information is appropriate. @c prevent bad page break with this line Here are macros for SDB and DWARF output. -@table @code -@findex SDB_DEBUGGING_INFO -@item SDB_DEBUGGING_INFO +@defmac SDB_DEBUGGING_INFO Define this macro if GCC should produce COFF-style debugging output for SDB in response to the @option{-g} option. +@end defmac -@findex DWARF_DEBUGGING_INFO -@item DWARF_DEBUGGING_INFO -Define this macro if GCC should produce dwarf format debugging output -in response to the @option{-g} option. - -@findex DWARF2_DEBUGGING_INFO -@item DWARF2_DEBUGGING_INFO +@defmac DWARF2_DEBUGGING_INFO Define this macro if GCC should produce dwarf version 2 format debugging output in response to the @option{-g} option. @@ -8043,84 +8046,77 @@ define @code{INCOMING_RETURN_ADDR_RTX} and either set @code{RTX_FRAME_RELATED_P} on the prologue insns if you use RTL for the prologue, or call @code{dwarf2out_def_cfa} and @code{dwarf2out_reg_save} as appropriate from @code{TARGET_ASM_FUNCTION_PROLOGUE} if you don't. +@end defmac -@findex DWARF2_FRAME_INFO -@item DWARF2_FRAME_INFO +@defmac DWARF2_FRAME_INFO Define this macro to a nonzero value if GCC should always output Dwarf 2 frame information. If @code{DWARF2_UNWIND_INFO} (@pxref{Exception Region Output} is nonzero, GCC will output this information not matter how you define @code{DWARF2_FRAME_INFO}. +@end defmac -@findex LINKER_DOES_NOT_WORK_WITH_DWARF2 -@item LINKER_DOES_NOT_WORK_WITH_DWARF2 -Define this macro if the linker does not work with Dwarf version 2. -Normally, if the user specifies only @option{-ggdb} GCC will use Dwarf -version 2 if available; this macro disables this. See the description -of the @code{PREFERRED_DEBUGGING_TYPE} macro for more details. - -@findex DWARF2_GENERATE_TEXT_SECTION_LABEL -@item DWARF2_GENERATE_TEXT_SECTION_LABEL +@defmac DWARF2_GENERATE_TEXT_SECTION_LABEL By default, the Dwarf 2 debugging information generator will generate a label to mark the beginning of the text section. If it is better simply to use the name of the text section itself, rather than an explicit label, to indicate the beginning of the text section, define this macro to zero. +@end defmac -@findex DWARF2_ASM_LINE_DEBUG_INFO -@item DWARF2_ASM_LINE_DEBUG_INFO +@defmac DWARF2_ASM_LINE_DEBUG_INFO Define this macro to be a nonzero value if the assembler can generate Dwarf 2 line debug info sections. This will result in much more compact line number tables, and hence is desirable if it works. +@end defmac -@findex ASM_OUTPUT_DWARF_DELTA -@item ASM_OUTPUT_DWARF_DELTA (@var{stream}, @var{size}, @var{label1}, @var{label2}) +@defmac ASM_OUTPUT_DWARF_DELTA (@var{stream}, @var{size}, @var{label1}, @var{label2}) A C statement to issue assembly directives that create a difference between the two given labels, using an integer of the given size. +@end defmac -@findex ASM_OUTPUT_DWARF_OFFSET -@item ASM_OUTPUT_DWARF_OFFSET (@var{stream}, @var{size}, @var{label}) +@defmac ASM_OUTPUT_DWARF_OFFSET (@var{stream}, @var{size}, @var{label}) A C statement to issue assembly directives that create a section-relative reference to the given label, using an integer of the given size. +@end defmac -@findex ASM_OUTPUT_DWARF_PCREL -@item ASM_OUTPUT_DWARF_PCREL (@var{stream}, @var{size}, @var{label}) +@defmac ASM_OUTPUT_DWARF_PCREL (@var{stream}, @var{size}, @var{label}) A C statement to issue assembly directives that create a self-relative reference to the given label, using an integer of the given size. +@end defmac -@findex PUT_SDB_@dots{} -@item PUT_SDB_@dots{} +@defmac PUT_SDB_@dots{} Define these macros to override the assembler syntax for the special SDB assembler directives. See @file{sdbout.c} for a list of these macros and their arguments. If the standard syntax is used, you need not define them yourself. +@end defmac -@findex SDB_DELIM -@item SDB_DELIM +@defmac SDB_DELIM Some assemblers do not support a semicolon as a delimiter, even between SDB assembler directives. In that case, define this macro to be the delimiter to use (usually @samp{\n}). It is not necessary to define a new set of @code{PUT_SDB_@var{op}} macros if this is the only change required. +@end defmac -@findex SDB_GENERATE_FAKE -@item SDB_GENERATE_FAKE +@defmac SDB_GENERATE_FAKE Define this macro to override the usual method of constructing a dummy name for anonymous structure and union types. See @file{sdbout.c} for more information. +@end defmac -@findex SDB_ALLOW_UNKNOWN_REFERENCES -@item SDB_ALLOW_UNKNOWN_REFERENCES +@defmac SDB_ALLOW_UNKNOWN_REFERENCES Define this macro to allow references to unknown structure, union, or enumeration tags to be emitted. Standard COFF does not allow handling of unknown references, MIPS ECOFF has support for it. +@end defmac -@findex SDB_ALLOW_FORWARD_REFERENCES -@item SDB_ALLOW_FORWARD_REFERENCES +@defmac SDB_ALLOW_FORWARD_REFERENCES Define this macro to allow references to structure, union, or enumeration tags that have not yet been seen to be handled. Some assemblers choke if forward tags are used, while some require it. -@end table +@end defmac @need 2000 @node VMS Debug @@ -8129,16 +8125,14 @@ assemblers choke if forward tags are used, while some require it. @c prevent bad page break with this line Here are macros for VMS debug format. -@table @code -@findex VMS_DEBUGGING_INFO -@item VMS_DEBUGGING_INFO +@defmac VMS_DEBUGGING_INFO Define this macro if GCC should produce debugging output for VMS in response to the @option{-g} option. The default behavior for VMS is to generate minimal debug info for a traceback in the absence of @option{-g} unless explicitly overridden with @option{-g0}. This behavior is controlled by @code{OPTIMIZATION_OPTIONS} and @code{OVERRIDE_OPTIONS}. -@end table +@end defmac @node Floating Point @section Cross Compilation and Floating Point @@ -8247,7 +8241,6 @@ integral, it is truncated. @end deftypefn @deftypefn Macro void REAL_VALUE_FROM_INT (REAL_VALUE_TYPE @var{x}, HOST_WIDE_INT @var{low}, HOST_WIDE_INT @var{high}, enum machine_mode @var{mode}) -@findex REAL_VALUE_FROM_INT Converts a double-precision integer found in @var{low} and @var{high}, into a floating point value which is then stored into @var{x}. The value is truncated to fit in mode @var{mode}. @@ -8258,9 +8251,7 @@ value is truncated to fit in mode @var{mode}. @cindex mode switching The following macros control mode switching optimizations: -@table @code -@findex OPTIMIZE_MODE_SWITCHING -@item OPTIMIZE_MODE_SWITCHING (@var{entity}) +@defmac OPTIMIZE_MODE_SWITCHING (@var{entity}) Define this macro if the port needs extra instructions inserted for mode switching in an optimizing compilation. @@ -8270,7 +8261,7 @@ the FPSCR PR bit has to be cleared, while for a double precision operation, this bit has to be set. Changing the PR bit requires a general purpose register as a scratch register, hence these FPSCR sets have to be inserted before reload, i.e.@: you can't put this into instruction emitting -or @code{MACHINE_DEPENDENT_REORG}. +or @code{TARGET_MACHINE_DEPENDENT_REORG}. You can have multiple entities that are mode-switched, and select at run time which entities actually need it. @code{OPTIMIZE_MODE_SWITCHING} should @@ -8278,10 +8269,11 @@ return nonzero for any @var{entity} that needs mode-switching. If you define this macro, you also have to define @code{NUM_MODES_FOR_MODE_SWITCHING}, @code{MODE_NEEDED}, @code{MODE_PRIORITY_TO_MODE} and @code{EMIT_MODE_SET}. -@code{NORMAL_MODE} is optional. +@code{MODE_AFTER}, @code{MODE_ENTRY}, and @code{MODE_EXIT} +are optional. +@end defmac -@findex NUM_MODES_FOR_MODE_SWITCHING -@item NUM_MODES_FOR_MODE_SWITCHING +@defmac NUM_MODES_FOR_MODE_SWITCHING If you define @code{OPTIMIZE_MODE_SWITCHING}, you have to define this as initializer for an array of integers. Each initializer element N refers to an entity that needs mode switching, and specifies the number @@ -8292,36 +8284,50 @@ entity in question. In macros that take mode arguments / yield a mode result, modes are represented as numbers 0 @dots{} N @minus{} 1. N is used to specify that no mode switch is needed / supplied. +@end defmac -@findex MODE_NEEDED -@item MODE_NEEDED (@var{entity}, @var{insn}) +@defmac MODE_NEEDED (@var{entity}, @var{insn}) @var{entity} is an integer specifying a mode-switched entity. If @code{OPTIMIZE_MODE_SWITCHING} is defined, you must define this macro to return an integer value not larger than the corresponding element in @code{NUM_MODES_FOR_MODE_SWITCHING}, to denote the mode that @var{entity} must be switched into prior to the execution of @var{insn}. +@end defmac + +@defmac MODE_AFTER (@var{mode}, @var{insn}) +If this macro is defined, it is evaluated for every @var{insn} during +mode switching. It determines the mode that an insn results in (if +different from the incoming mode). +@end defmac + +@defmac MODE_ENTRY (@var{entity}) +If this macro is defined, it is evaluated for every @var{entity} that needs +mode switching. It should evaluate to an integer, which is a mode that +@var{entity} is assumed to be switched to at function entry. If @code{MODE_ENTRY} +is defined then @code{MODE_EXIT} must be defined. +@end defmac -@findex NORMAL_MODE -@item NORMAL_MODE (@var{entity}) +@defmac MODE_EXIT (@var{entity}) If this macro is defined, it is evaluated for every @var{entity} that needs -mode switching. It should evaluate to an integer, which is a mode that -@var{entity} is assumed to be switched to at function entry and exit. +mode switching. It should evaluate to an integer, which is a mode that +@var{entity} is assumed to be switched to at function exit. If @code{MODE_EXIT} +is defined then @code{MODE_ENTRY} must be defined. +@end defmac -@findex MODE_PRIORITY_TO_MODE -@item MODE_PRIORITY_TO_MODE (@var{entity}, @var{n}) +@defmac MODE_PRIORITY_TO_MODE (@var{entity}, @var{n}) This macro specifies the order in which modes for @var{entity} are processed. 0 is the highest priority, @code{NUM_MODES_FOR_MODE_SWITCHING[@var{entity}] - 1} the lowest. The value of the macro should be an integer designating a mode for @var{entity}. For any fixed @var{entity}, @code{mode_priority_to_mode} (@var{entity}, @var{n}) shall be a bijection in 0 @dots{} @code{num_modes_for_mode_switching[@var{entity}] - 1}. +@end defmac -@findex EMIT_MODE_SET -@item EMIT_MODE_SET (@var{entity}, @var{mode}, @var{hard_regs_live}) +@defmac EMIT_MODE_SET (@var{entity}, @var{mode}, @var{hard_regs_live}) Generate one or more insns to set @var{entity} to @var{mode}. @var{hard_reg_live} is the set of hard registers live at the point where the insn(s) are to be inserted. -@end table +@end defmac @node Target Attributes @section Defining target-specific uses of @code{__attribute__} @@ -8374,7 +8380,7 @@ call @code{merge_attributes} to handle machine-independent merging. @findex TARGET_DLLIMPORT_DECL_ATTRIBUTES If the only target-specific handling you require is @samp{dllimport} for -Windows targets, you should define the macro +Microsoft Windows targets, you should define the macro @code{TARGET_DLLIMPORT_DECL_ATTRIBUTES}. This links in a function called @code{merge_dllimport_decl_attributes} which can then be defined as the expansion of @code{TARGET_MERGE_DECL_ATTRIBUTES}. This is done @@ -8407,7 +8413,7 @@ target specific attribute attached to it, it will not be inlined. @cindex MIPS coprocessor-definition macros The MIPS specification allows MIPS implementations to have as many as 4 -coprocessors, each with as many as 32 private registers. gcc supports +coprocessors, each with as many as 32 private registers. GCC supports accessing these registers and transferring values between the registers and memory using asm-ized variables. For example: @@ -8433,18 +8439,38 @@ floating-point support; they are not included in this mechanism. There is one macro used in defining the MIPS coprocessor interface which you may want to override in subtargets; it is described below. -@table @code - -@item ALL_COP_ADDITIONAL_REGISTER_NAMES -@findex ALL_COP_ADDITIONAL_REGISTER_NAMES +@defmac ALL_COP_ADDITIONAL_REGISTER_NAMES A comma-separated list (with leading comma) of pairs describing the alternate names of coprocessor registers. The format of each entry should be @smallexample @{ @var{alternatename}, @var{register_number}@} @end smallexample Default: empty. +@end defmac + +@node PCH Target +@section Parameters for Precompiled Header Validity Checking +@cindex parameters, precompiled headers + +@deftypefn {Target Hook} void * TARGET_GET_PCH_VALIDITY (size_t * @var{sz}) +Define this hook if your target needs to check a different collection +of flags than the default, which is every flag defined by +@code{TARGET_SWITCHES} and @code{TARGET_OPTIONS}. It should return +some data which will be saved in the PCH file and presented to +@code{TARGET_PCH_VALID_P} later; it should set @code{SZ} to the size +of the data. +@end deftypefn -@end table +@deftypefn {Target Hook} const char * TARGET_PCH_VALID_P (const void * @var{data}, size_t @var{sz}) +Define this hook if your target needs to check a different collection of +flags than the default, which is every flag defined by @code{TARGET_SWITCHES} +and @code{TARGET_OPTIONS}. It is given data which came from +@code{TARGET_GET_PCH_VALIDITY} (in this version of this compiler, so there +is no need for extensive validity checking). It returns @code{NULL} if +it is safe to load a PCH file with this data, or a suitable error message +if not. The error message will be presented to the user, so it should +be localized. +@end deftypefn @node Misc @section Miscellaneous Parameters @@ -8453,9 +8479,7 @@ Default: empty. @c prevent bad page break with this line Here are several miscellaneous parameters. -@table @code -@item PREDICATE_CODES -@findex PREDICATE_CODES +@defmac PREDICATE_CODES Define this if you have defined special-purpose predicates in the file @file{@var{machine}.c}. This macro is called within an initializer of an array of structures. The first field in the structure is the name of a @@ -8480,9 +8504,9 @@ patterns. For each predicate function named in @code{PREDICATE_CODES}, a declaration will be generated in @file{insn-codes.h}. +@end defmac -@item SPECIAL_MODE_PREDICATES -@findex SPECIAL_MODE_PREDICATES +@defmac SPECIAL_MODE_PREDICATES Define this if you have special predicates that know special things about modes. Genrecog will warn about certain forms of @code{match_operand} without a mode; if the operand predicate is @@ -8497,14 +8521,14 @@ for a byte extraction from @code{%ah} etc.). #define SPECIAL_MODE_PREDICATES \ "ext_register_operand", @end smallexample +@end defmac -@findex CASE_VECTOR_MODE -@item CASE_VECTOR_MODE +@defmac CASE_VECTOR_MODE An alias for a machine mode name. This is the machine mode that elements of a jump-table should have. +@end defmac -@findex CASE_VECTOR_SHORTEN_MODE -@item CASE_VECTOR_SHORTEN_MODE (@var{min_offset}, @var{max_offset}, @var{body}) +@defmac CASE_VECTOR_SHORTEN_MODE (@var{min_offset}, @var{max_offset}, @var{body}) Optional: return the preferred mode for an @code{addr_diff_vec} when the minimum and maximum offset are known. If you define this, it enables extra code in branch shortening to deal with @code{addr_diff_vec}. @@ -8512,74 +8536,97 @@ To make this work, you also have to define @code{INSN_ALIGN} and make the alignment for @code{addr_diff_vec} explicit. The @var{body} argument is provided so that the offset_unsigned and scale flags can be updated. +@end defmac -@findex CASE_VECTOR_PC_RELATIVE -@item CASE_VECTOR_PC_RELATIVE +@defmac CASE_VECTOR_PC_RELATIVE Define this macro to be a C expression to indicate when jump-tables -should contain relative addresses. If jump-tables never contain -relative addresses, then you need not define this macro. +should contain relative addresses. You need not define this macro if +jump-tables never contain relative addresses, or jump-tables should +contain relative addresses only when @option{-fPIC} or @option{-fPIC} +is in effect. +@end defmac -@findex CASE_DROPS_THROUGH -@item CASE_DROPS_THROUGH +@defmac CASE_DROPS_THROUGH Define this if control falls through a @code{case} insn when the index value is out of range. This means the specified default-label is actually ignored by the @code{case} insn proper. +@end defmac -@findex CASE_VALUES_THRESHOLD -@item CASE_VALUES_THRESHOLD +@defmac CASE_VALUES_THRESHOLD Define this to be the smallest number of different values for which it is best to use a jump-table instead of a tree of conditional branches. The default is four for machines with a @code{casesi} instruction and five otherwise. This is best for most machines. +@end defmac + +@defmac CASE_USE_BIT_TESTS +Define this macro to be a C expression to indicate whether C switch +statements may be implemented by a sequence of bit tests. This is +advantageous on processors that can efficiently implement left shift +of 1 by the number of bits held in a register, but inappropriate on +targets that would require a loop. By default, this macro returns +@code{true} if the target defines an @code{ashlsi3} pattern, and +@code{false} otherwise. +@end defmac -@findex WORD_REGISTER_OPERATIONS -@item WORD_REGISTER_OPERATIONS +@defmac WORD_REGISTER_OPERATIONS Define this macro if operations between registers with integral mode smaller than a word are always performed on the entire register. Most RISC machines have this property and most CISC machines do not. +@end defmac -@findex LOAD_EXTEND_OP -@item LOAD_EXTEND_OP (@var{mode}) +@defmac LOAD_EXTEND_OP (@var{mem_mode}) Define this macro to be a C expression indicating when insns that read -memory in @var{mode}, an integral mode narrower than a word, set the -bits outside of @var{mode} to be either the sign-extension or the +memory in @var{mem_mode}, an integral mode narrower than a word, set the +bits outside of @var{mem_mode} to be either the sign-extension or the zero-extension of the data read. Return @code{SIGN_EXTEND} for values -of @var{mode} for which the +of @var{mem_mode} for which the insn sign-extends, @code{ZERO_EXTEND} for which it zero-extends, and @code{NIL} for other modes. -This macro is not called with @var{mode} non-integral or with a width +This macro is not called with @var{mem_mode} non-integral or with a width greater than or equal to @code{BITS_PER_WORD}, so you may return any value in this case. Do not define this macro if it would always return @code{NIL}. On machines where this macro is defined, you will normally define it as the constant @code{SIGN_EXTEND} or @code{ZERO_EXTEND}. -@findex SHORT_IMMEDIATES_SIGN_EXTEND -@item SHORT_IMMEDIATES_SIGN_EXTEND +You may return a non-@code{NIL} value even if for some hard registers +the sign extension is not performed, if for the @code{REGNO_REG_CLASS} +of these hard registers @code{CANNOT_CHANGE_MODE_CLASS} returns nonzero +when the @var{from} mode is @var{mem_mode} and the @var{to} mode is any +integral mode larger than this but not larger than @code{word_mode}. + +You must return @code{NIL} if for some hard registers that allow this +mode, @code{CANNOT_CHANGE_MODE_CLASS} says that they cannot change to +@code{word_mode}, but that they can change to another integral mode that +is larger then @var{mem_mode} but still smaller than @code{word_mode}. +@end defmac + +@defmac SHORT_IMMEDIATES_SIGN_EXTEND Define this macro if loading short immediate values into registers sign extends. +@end defmac -@findex FIXUNS_TRUNC_LIKE_FIX_TRUNC -@item FIXUNS_TRUNC_LIKE_FIX_TRUNC +@defmac FIXUNS_TRUNC_LIKE_FIX_TRUNC Define this macro if the same instructions that convert a floating point number to a signed fixed point number also convert validly to an unsigned one. +@end defmac -@findex MOVE_MAX -@item MOVE_MAX +@defmac MOVE_MAX The maximum number of bytes that a single instruction can move quickly between memory and registers or between two memory locations. +@end defmac -@findex MAX_MOVE_MAX -@item MAX_MOVE_MAX +@defmac MAX_MOVE_MAX The maximum number of bytes that a single instruction can move quickly between memory and registers or between two memory locations. If this is undefined, the default is @code{MOVE_MAX}. Otherwise, it is the constant value that is the largest value that @code{MOVE_MAX} can have at run-time. +@end defmac -@findex SHIFT_COUNT_TRUNCATED -@item SHIFT_COUNT_TRUNCATED +@defmac SHIFT_COUNT_TRUNCATED A C expression that is nonzero if on this machine the number of bits actually used for the count of a shift operation is equal to the number of bits needed to represent the size of the object being shifted. When @@ -8602,9 +8649,9 @@ such machines. Instead, add patterns to the @file{md} file that include the implied truncation of the shift instructions. You need not define this macro if it would always have the value of zero. +@end defmac -@findex TRULY_NOOP_TRUNCATION -@item TRULY_NOOP_TRUNCATION (@var{outprec}, @var{inprec}) +@defmac TRULY_NOOP_TRUNCATION (@var{outprec}, @var{inprec}) A C expression which is nonzero if on this machine it is safe to ``convert'' an integer of @var{inprec} bits to one of @var{outprec} bits (where @var{outprec} is smaller than @var{inprec}) by merely @@ -8618,9 +8665,9 @@ When @code{TRULY_NOOP_TRUNCATION} returns 1 for a pair of sizes for modes for which @code{MODES_TIEABLE_P} is 0, suboptimal code can result. If this is the case, making @code{TRULY_NOOP_TRUNCATION} return 0 in such cases may improve things. +@end defmac -@findex STORE_FLAG_VALUE -@item STORE_FLAG_VALUE +@defmac STORE_FLAG_VALUE A C expression describing the value returned by a comparison operator with an integral mode and stored by a store-flag instruction (@samp{s@var{cond}}) when the condition is true. This description must @@ -8713,19 +8760,38 @@ and @code{decscc}, respectively, for the patterns which perform @file{rs6000.md} for some examples. The GNU Superoptizer can be used to find such instruction sequences on other machines. -You need not define @code{STORE_FLAG_VALUE} if the machine has no store-flag -instructions. +If this macro is not defined, the default value, 1, is used. You need +not define @code{STORE_FLAG_VALUE} if the machine has no store-flag +instructions, or if the value generated by these instructions is 1. +@end defmac -@findex FLOAT_STORE_FLAG_VALUE -@item FLOAT_STORE_FLAG_VALUE (@var{mode}) +@defmac FLOAT_STORE_FLAG_VALUE (@var{mode}) A C expression that gives a nonzero @code{REAL_VALUE_TYPE} value that is returned when comparison operators with floating-point results are true. Define this macro on machine that have comparison operations that return floating-point values. If there are no such operations, do not define this macro. +@end defmac -@findex Pmode -@item Pmode +@defmac CLZ_DEFINED_VALUE_AT_ZERO (@var{mode}, @var{value}) +@defmacx CTZ_DEFINED_VALUE_AT_ZERO (@var{mode}, @var{value}) +A C expression that evaluates to true if the architecture defines a value +for @code{clz} or @code{ctz} with a zero operand. If so, @var{value} +should be set to this value. If this macro is not defined, the value of +@code{clz} or @code{ctz} is assumed to be undefined. + +This macro must be defined if the target's expansion for @code{ffs} +relies on a particular value to get correct results. Otherwise it +is not necessary, though it may be used to optimize some corner cases. + +Note that regardless of this macro the ``definedness'' of @code{clz} +and @code{ctz} at zero do @emph{not} extend to the builtin functions +visible to the user. Thus one may be free to adjust the value at will +to match the target expansion of these operations without fear of +breaking the API. +@end defmac + +@defmac Pmode An alias for the machine mode for pointers. On most machines, define this to be the integer mode corresponding to the width of a hardware pointer; @code{SImode} on 32-bit machine or @code{DImode} on 64-bit machines. @@ -8736,15 +8802,15 @@ The width of @code{Pmode} must be at least as large as the value of @code{POINTER_SIZE}. If it is not equal, you must define the macro @code{POINTERS_EXTEND_UNSIGNED} to specify how pointers are extended to @code{Pmode}. +@end defmac -@findex FUNCTION_MODE -@item FUNCTION_MODE +@defmac FUNCTION_MODE An alias for the machine mode used for memory references to functions being called, in @code{call} RTL expressions. On most machines this should be @code{QImode}. +@end defmac -@findex INTEGRATE_THRESHOLD -@item INTEGRATE_THRESHOLD (@var{decl}) +@defmac INTEGRATE_THRESHOLD (@var{decl}) A C expression for the maximum number of instructions above which the function @var{decl} should not be inlined. @var{decl} is a @code{FUNCTION_DECL} node. @@ -8752,9 +8818,9 @@ function @var{decl} should not be inlined. @var{decl} is a The default definition of this macro is 64 plus 8 times the number of arguments that the function accepts. Some people think a larger threshold should be used on RISC machines. +@end defmac -@findex STDC_0_IN_SYSTEM_HEADERS -@item STDC_0_IN_SYSTEM_HEADERS +@defmac STDC_0_IN_SYSTEM_HEADERS In normal operation, the preprocessor expands @code{__STDC__} to the constant 1, to signify that GCC conforms to ISO Standard C@. On some hosts, like Solaris, the system compiler uses a different convention, @@ -8764,27 +8830,21 @@ strict conformance to the C Standard. Defining @code{STDC_0_IN_SYSTEM_HEADERS} makes GNU CPP follows the host convention when processing system header files, but when processing user files @code{__STDC__} will always expand to 1. +@end defmac -@findex NO_IMPLICIT_EXTERN_C -@item NO_IMPLICIT_EXTERN_C +@defmac NO_IMPLICIT_EXTERN_C Define this macro if the system header files support C++ as well as C@. This macro inhibits the usual method of using system header files in C++, which is to pretend that the file's contents are enclosed in @samp{extern "C" @{@dots{}@}}. +@end defmac -@findex HANDLE_PRAGMA -@item HANDLE_PRAGMA (@var{getc}, @var{ungetc}, @var{name}) -This macro is no longer supported. You must use -@code{REGISTER_TARGET_PRAGMAS} instead. - -@findex REGISTER_TARGET_PRAGMAS @findex #pragma @findex pragma -@item REGISTER_TARGET_PRAGMAS (@var{pfile}) +@defmac REGISTER_TARGET_PRAGMAS () Define this macro if you want to implement any target-specific pragmas. If defined, it is a C expression which makes a series of calls to -@code{cpp_register_pragma} for each pragma, with @var{pfile} passed as -the first argument to to these functions. The macro may also do any +@code{c_register_pragma} for each pragma. The macro may also do any setup required for the pragmas. The primary reason to define this macro is to provide compatibility with @@ -8797,10 +8857,11 @@ defining the target hook @samp{TARGET_INSERT_ATTRIBUTES} as well. Preprocessor macros that appear on pragma lines are not expanded. All @samp{#pragma} directives that do not match any registered pragma are silently ignored, unless the user specifies @option{-Wunknown-pragmas}. +@end defmac -@deftypefun void cpp_register_pragma (cpp_reader *@var{pfile}, const char *@var{space}, const char *@var{name}, void (*@var{callback}) (cpp_reader *)) +@deftypefun void c_register_pragma (const char *@var{space}, const char *@var{name}, void (*@var{callback}) (struct cpp_reader *)) -Each call to @code{cpp_register_pragma} establishes one pragma. The +Each call to @code{c_register_pragma} establishes one pragma. The @var{callback} routine will be called when the preprocessor encounters a pragma of the form @@ -8814,7 +8875,7 @@ routine receives @var{pfile} as its first argument, which can be passed on to cpplib's functions if necessary. You can lex tokens after the @var{name} by calling @code{c_lex}. Tokens that are not read by the callback will be silently ignored. The end of the line is indicated by -a token of type @code{CPP_EOF}. +a token of type @code{CPP_EOF} For an example use of this routine, see @file{c4x.h} and the callback routines defined in @file{c4x-c.c}. @@ -8832,10 +8893,9 @@ rule to the makefile fragment pointed to by @code{tmake_file} that shows how to build this object file. @end deftypefun -@findex HANDLE_SYSV_PRAGMA @findex #pragma @findex pragma -@item HANDLE_SYSV_PRAGMA +@defmac HANDLE_SYSV_PRAGMA Define this macro (to a value of 1) if you want the System V style pragmas @samp{#pragma pack(<n>)} and @samp{#pragma weak <name> [=<value>]} to be supported by gcc. @@ -8863,11 +8923,11 @@ may affect its placement. The weak pragma only works if @code{SUPPORTS_WEAK} and @code{ASM_WEAKEN_LABEL} are defined. If enabled it allows the creation of specifically named weak labels, optionally with a value. +@end defmac -@findex HANDLE_PRAGMA_PACK_PUSH_POP @findex #pragma @findex pragma -@item HANDLE_PRAGMA_PACK_PUSH_POP +@defmac HANDLE_PRAGMA_PACK_PUSH_POP Define this macro (to a value of 1) if you want to support the Win32 style pragmas @samp{#pragma pack(push,@var{n})} and @samp{#pragma pack(pop)}. The @samp{pack(push,@var{n})} pragma specifies the maximum alignment @@ -8877,30 +8937,30 @@ pack value of zero resets the behavior to the default. Successive invocations of this pragma cause the previous values to be stacked, so that invocations of @samp{#pragma pack(pop)} will return to the previous value. +@end defmac -@findex DOLLARS_IN_IDENTIFIERS -@item DOLLARS_IN_IDENTIFIERS -Define this macro to control use of the character @samp{$} in identifier -names. 0 means @samp{$} is not allowed by default; 1 means it is allowed. -1 is the default; there is no need to define this macro in that case. -This macro controls the compiler proper; it does not affect the preprocessor. +@defmac DOLLARS_IN_IDENTIFIERS +Define this macro to control use of the character @samp{$} in +identifier names for the C family of languages. 0 means @samp{$} is +not allowed by default; 1 means it is allowed. 1 is the default; +there is no need to define this macro in that case. +@end defmac -@findex NO_DOLLAR_IN_LABEL -@item NO_DOLLAR_IN_LABEL +@defmac NO_DOLLAR_IN_LABEL Define this macro if the assembler does not accept the character @samp{$} in label names. By default constructors and destructors in G++ have @samp{$} in the identifiers. If this macro is defined, @samp{.} is used instead. +@end defmac -@findex NO_DOT_IN_LABEL -@item NO_DOT_IN_LABEL +@defmac NO_DOT_IN_LABEL Define this macro if the assembler does not accept the character @samp{.} in label names. By default constructors and destructors in G++ have names that use @samp{.}. If this macro is defined, these names are rewritten to avoid @samp{.}. +@end defmac -@findex DEFAULT_MAIN_RETURN -@item DEFAULT_MAIN_RETURN +@defmac DEFAULT_MAIN_RETURN Define this macro if the target system expects every program's @code{main} function to return a standard ``success'' value by default (if no other value is explicitly returned). @@ -8908,33 +8968,9 @@ value is explicitly returned). The definition should be a C statement (sans semicolon) to generate the appropriate rtl instructions. It is used only when compiling the end of @code{main}. +@end defmac -@item NEED_ATEXIT -@findex NEED_ATEXIT -Define this if the target system lacks the function @code{atexit} -from the ISO C standard. If this macro is defined, a default definition -will be provided to support C++. If @code{ON_EXIT} is not defined, -a default @code{exit} function will also be provided. - -@item ON_EXIT -@findex ON_EXIT -Define this macro if the target has another way to implement atexit -functionality without replacing @code{exit}. For instance, SunOS 4 has -a similar @code{on_exit} library function. - -The definition should be a functional macro which can be used just like -the @code{atexit} function. - -@item EXIT_BODY -@findex EXIT_BODY -Define this if your @code{exit} function needs to do something -besides calling an external function @code{_cleanup} before -terminating with @code{_exit}. The @code{EXIT_BODY} macro is -only needed if @code{NEED_ATEXIT} is defined and @code{ON_EXIT} is not -defined. - -@findex INSN_SETS_ARE_DELAYED -@item INSN_SETS_ARE_DELAYED (@var{insn}) +@defmac INSN_SETS_ARE_DELAYED (@var{insn}) Define this macro as a C expression that is nonzero if it is safe for the delay slot scheduler to place instructions in the delay slot of @var{insn}, even if they appear to use a resource set or clobbered in @var{insn}. @@ -8944,9 +8980,9 @@ or @code{jump_insn} is really a function call and hence has this behavior, you should define this macro. You need not define this macro if it would always return zero. +@end defmac -@findex INSN_REFERENCES_ARE_DELAYED -@item INSN_REFERENCES_ARE_DELAYED (@var{insn}) +@defmac INSN_REFERENCES_ARE_DELAYED (@var{insn}) Define this macro as a C expression that is nonzero if it is safe for the delay slot scheduler to place instructions in the delay slot of @var{insn}, even if they appear to set or clobber a resource referenced in @var{insn}. @@ -8958,69 +8994,53 @@ instructions which copy arguments into the argument registers into the delay slot of @var{insn}. You need not define this macro if it would always return zero. +@end defmac -@findex MACHINE_DEPENDENT_REORG -@item MACHINE_DEPENDENT_REORG (@var{insn}) -In rare cases, correct code generation requires extra machine -dependent processing between the second jump optimization pass and -delayed branch scheduling. On those machines, define this macro as a C -statement to act on the code starting at @var{insn}. - -@findex MULTIPLE_SYMBOL_SPACES -@item MULTIPLE_SYMBOL_SPACES +@defmac MULTIPLE_SYMBOL_SPACES Define this macro if in some cases global symbols from one translation unit may not be bound to undefined symbols in another translation unit without user intervention. For instance, under Microsoft Windows symbols must be explicitly imported from shared libraries (DLLs). +@end defmac -@findex MD_ASM_CLOBBERS -@item MD_ASM_CLOBBERS (@var{clobbers}) +@defmac MD_ASM_CLOBBERS (@var{clobbers}) A C statement that adds to @var{clobbers} @code{STRING_CST} trees for any hard regs the port wishes to automatically clobber for all asms. +@end defmac -@findex MAX_INTEGER_COMPUTATION_MODE -@item MAX_INTEGER_COMPUTATION_MODE -Define this to the largest integer machine mode which can be used for -operations other than load, store and copy operations. - -You need only define this macro if the target holds values larger than -@code{word_mode} in general purpose registers. Most targets should not define -this macro. - -@findex MATH_LIBRARY -@item MATH_LIBRARY +@defmac MATH_LIBRARY Define this macro as a C string constant for the linker argument to link in the system math library, or @samp{""} if the target does not have a separate math library. You need only define this macro if the default of @samp{"-lm"} is wrong. +@end defmac -@findex LIBRARY_PATH_ENV -@item LIBRARY_PATH_ENV +@defmac LIBRARY_PATH_ENV Define this macro as a C string constant for the environment variable that specifies where the linker should look for libraries. You need only define this macro if the default of @samp{"LIBRARY_PATH"} is wrong. +@end defmac -@findex TARGET_HAS_F_SETLKW -@item TARGET_HAS_F_SETLKW +@defmac TARGET_HAS_F_SETLKW Define this macro if the target supports file locking with fcntl / F_SETLKW@. Note that this functionality is part of POSIX@. Defining @code{TARGET_HAS_F_SETLKW} will enable the test coverage code to use file locking when exiting a program, which avoids race conditions if the program has forked. +@end defmac -@findex MAX_CONDITIONAL_EXECUTE -@item MAX_CONDITIONAL_EXECUTE +@defmac MAX_CONDITIONAL_EXECUTE A C expression for the maximum number of instructions to execute via conditional execution instructions instead of a branch. A value of @code{BRANCH_COST}+1 is the default if the machine does not use cc0, and 1 if it does use cc0. +@end defmac -@findex IFCVT_MODIFY_TESTS -@item IFCVT_MODIFY_TESTS(@var{ce_info}, @var{true_expr}, @var{false_expr}) +@defmac IFCVT_MODIFY_TESTS (@var{ce_info}, @var{true_expr}, @var{false_expr}) Used if the target needs to perform machine-dependent modifications on the conditionals used for turning basic blocks into conditionally executed code. @var{ce_info} points to a data structure, @code{struct ce_if_block}, which @@ -9028,47 +9048,60 @@ contains information about the currently processed blocks. @var{true_expr} and @var{false_expr} are the tests that are used for converting the then-block and the else-block, respectively. Set either @var{true_expr} or @var{false_expr} to a null pointer if the tests cannot be converted. +@end defmac -@findex IFCVT_MODIFY_MULTIPLE_TESTS -@item IFCVT_MODIFY_MULTIPLE_TESTS(@var{ce_info}, @var{bb}, @var{true_expr}, @var{false_expr}) +@defmac IFCVT_MODIFY_MULTIPLE_TESTS (@var{ce_info}, @var{bb}, @var{true_expr}, @var{false_expr}) Like @code{IFCVT_MODIFY_TESTS}, but used when converting more complicated if-statements into conditions combined by @code{and} and @code{or} operations. @var{bb} contains the basic block that contains the test that is currently being processed and about to be turned into a condition. +@end defmac -@findex IFCVT_MODIFY_INSN -@item IFCVT_MODIFY_INSN(@var{ce_info}, @var{pattern}, @var{insn}) +@defmac IFCVT_MODIFY_INSN (@var{ce_info}, @var{pattern}, @var{insn}) A C expression to modify the @var{PATTERN} of an @var{INSN} that is to be converted to conditional execution format. @var{ce_info} points to a data structure, @code{struct ce_if_block}, which contains information about the currently processed blocks. +@end defmac -@findex IFCVT_MODIFY_FINAL -@item IFCVT_MODIFY_FINAL(@var{ce_info}) +@defmac IFCVT_MODIFY_FINAL (@var{ce_info}) A C expression to perform any final machine dependent modifications in converting code to conditional execution. The involved basic blocks can be found in the @code{struct ce_if_block} structure that is pointed to by @var{ce_info}. +@end defmac -@findex IFCVT_MODIFY_CANCEL -@item IFCVT_MODIFY_CANCEL(@var{ce_info}) +@defmac IFCVT_MODIFY_CANCEL (@var{ce_info}) A C expression to cancel any machine dependent modifications in converting code to conditional execution. The involved basic blocks can be found in the @code{struct ce_if_block} structure that is pointed to by @var{ce_info}. +@end defmac -@findex IFCVT_INIT_EXTRA_FIELDS -@item IFCVT_INIT_EXTRA_FIELDS(@var{ce_info}) +@defmac IFCVT_INIT_EXTRA_FIELDS (@var{ce_info}) A C expression to initialize any extra fields in a @code{struct ce_if_block} structure, which are defined by the @code{IFCVT_EXTRA_FIELDS} macro. +@end defmac -@findex IFCVT_EXTRA_FIELDS -@item IFCVT_EXTRA_FIELDS +@defmac IFCVT_EXTRA_FIELDS If defined, it should expand to a set of field declarations that will be added to the @code{struct ce_if_block} structure. These should be initialized by the @code{IFCVT_INIT_EXTRA_FIELDS} macro. +@end defmac -@end table +@deftypefn {Target Hook} void TARGET_MACHINE_DEPENDENT_REORG () +If non-null, this hook performs a target-specific pass over the +instruction stream. The compiler will run it at all optimization levels, +just before the point at which it normally does delayed-branch scheduling. + +The exact purpose of the hook varies from target to target. Some use +it to do transformations that are necessary for correctness, such as +laying out in-function constant pools or avoiding hardware hazards. +Others use it as an opportunity to do some machine-dependent optimizations. + +You need not implement the hook if it has nothing to do. The default +definition is null. +@end deftypefn @deftypefn {Target Hook} void TARGET_INIT_BUILTINS () Define this hook if you have any machine-specific built-in functions @@ -9099,9 +9132,7 @@ ignored. This function should return the result of the call to the built-in function. @end deftypefn -@table @code -@findex MD_CAN_REDIRECT_BRANCH -@item MD_CAN_REDIRECT_BRANCH(@var{branch1}, @var{branch2}) +@defmac MD_CAN_REDIRECT_BRANCH (@var{branch1}, @var{branch2}) Take a branch insn in @var{branch1} and another in @var{branch2}. Return true if redirecting @var{branch1} to the destination of @@ -9110,9 +9141,9 @@ Return true if redirecting @var{branch1} to the destination of On some targets, branches may have a limited range. Optimizing the filling of delay slots can result in branches being redirected, and this may in turn cause a branch offset to overflow. +@end defmac -@findex ALLOCATE_INITIAL_VALUE -@item ALLOCATE_INITIAL_VALUE(@var{hard_reg}) +@defmac ALLOCATE_INITIAL_VALUE (@var{hard_reg}) When the initial value of a hard register has been copied in a pseudo register, it is often not necessary to actually allocate another register @@ -9130,34 +9161,34 @@ it might decide to use another register anyways. You may use @code{current_function_leaf_function} in the definition of the macro, functions that use @code{REG_N_SETS}, to determine if the hard register in question will not be clobbered. +@end defmac -@findex TARGET_OBJECT_SUFFIX -@item TARGET_OBJECT_SUFFIX +@defmac TARGET_OBJECT_SUFFIX Define this macro to be a C string representing the suffix for object files on your target machine. If you do not define this macro, GCC will use @samp{.o} as the suffix for object files. +@end defmac -@findex TARGET_EXECUTABLE_SUFFIX -@item TARGET_EXECUTABLE_SUFFIX +@defmac TARGET_EXECUTABLE_SUFFIX Define this macro to be a C string representing the suffix to be automatically added to executable files on your target machine. If you do not define this macro, GCC will use the null string as the suffix for executable files. +@end defmac -@findex COLLECT_EXPORT_LIST -@item COLLECT_EXPORT_LIST +@defmac COLLECT_EXPORT_LIST If defined, @code{collect2} will scan the individual object files specified on its command line and create an export list for the linker. Define this macro for systems like AIX, where the linker discards object files that are not referenced from @code{main} and uses export lists. +@end defmac -@findex MODIFY_JNI_METHOD_CALL -@item MODIFY_JNI_METHOD_CALL (@var{mdecl}) +@defmac MODIFY_JNI_METHOD_CALL (@var{mdecl}) Define this macro to a C expression representing a variant of the method call @var{mdecl}, if Java Native Interface (JNI) methods must be invoked differently from other methods on your target. -For example, on 32-bit Windows, JNI methods must be invoked using +For example, on 32-bit Microsoft Windows, JNI methods must be invoked using the @code{stdcall} calling convention and this macro is then defined as this expression: @@ -9167,8 +9198,7 @@ build_type_attribute_variant (@var{mdecl}, (get_identifier ("stdcall"), NULL)) @end smallexample - -@end table +@end defmac @deftypefn {Target Hook} bool TARGET_CANNOT_MODIFY_JUMPS_P (void) This target hook returns @code{true} past the point in which new jump @@ -9184,3 +9214,35 @@ cannot_modify_jumps_past_reload_p () @} @end smallexample @end deftypefn + +@deftypefn {Target Hook} int TARGET_BRANCH_TARGET_REGISTER_CLASS (void) +This target hook returns a register class for which branch target register +optimizations should be applied. All registers in this class should be +usable interchangeably. After reload, registers in this class will be +re-allocated and loads will be hoisted out of loops and be subjected +to inter-block scheduling. +@end deftypefn + +@deftypefn {Target Hook} bool TARGET_BRANCH_TARGET_REGISTER_CALLEE_SAVED (bool @var{after_prologue_epilogue_gen}) +Branch target register optimization will by default exclude callee-saved +registers +that are not already live during the current function; if this target hook +returns true, they will be included. The target code must than make sure +that all target registers in the class returned by +@samp{TARGET_BRANCH_TARGET_REGISTER_CLASS} that might need saving are +saved. @var{after_prologue_epilogue_gen} indicates if prologues and +epilogues have already been generated. Note, even if you only return +true when @var{after_prologue_epilogue_gen} is false, you still are likely +to have to make special provisions in @code{INITIAL_ELIMINATION_OFFSET} +to reserve space for caller-saved target registers. +@end deftypefn + +@defmac POWI_MAX_MULTS +If defined, this macro is interpreted as a signed integer C expression +that specifies the maximum number of floating point multiplications +that should be emitted when expanding exponentiation by an integer +constant inline. When this value is defined, exponentiation requiring +more than this number of multiplications is implemented by calling the +system library's @code{pow}, @code{powf} or @code{powl} routines. +The default value places no upper bound on the multiplication count. +@end defmac |