diff options
Diffstat (limited to 'contrib/gcc/doc/invoke.texi')
| -rw-r--r-- | contrib/gcc/doc/invoke.texi | 66 |
1 files changed, 47 insertions, 19 deletions
diff --git a/contrib/gcc/doc/invoke.texi b/contrib/gcc/doc/invoke.texi index a3b53ed..d60d6fc 100644 --- a/contrib/gcc/doc/invoke.texi +++ b/contrib/gcc/doc/invoke.texi @@ -169,7 +169,7 @@ in the following sections. -fallow-single-precision -fcond-mismatch @gol -fsigned-bitfields -fsigned-char @gol -funsigned-bitfields -funsigned-char @gol --fwritable-strings -fshort-wchar} +-fwritable-strings} @item C++ Language Options @xref{C++ Dialect Options,,Options Controlling C++ Dialect}. @@ -279,8 +279,8 @@ in the following sections. -frerun-cse-after-loop -frerun-loop-opt @gol -fschedule-insns -fschedule-insns2 @gol -fsingle-precision-constant -fssa -fssa-ccp -fssa-dce @gol --fstrength-reduce -fstrict-aliasing -fthread-jumps -ftrapv @gol --funroll-all-loops -funroll-loops @gol +-fstrength-reduce -fstrict-aliasing -fthread-jumps @gol +-ftrapv -funroll-all-loops -funroll-loops @gol --param @var{name}=@var{value} -O -O0 -O1 -O2 -O3 -Os} @@ -444,7 +444,7 @@ in the following sections. -mno-relocatable -mrelocatable-lib -mno-relocatable-lib @gol -mtoc -mno-toc -mlittle -mlittle-endian -mbig -mbig-endian @gol -mcall-aix -mcall-sysv -mcall-netbsd @gol --maix-struct-return -msvr4-struct-return +-maix-struct-return -msvr4-struct-return @gol -mabi=altivec -mabi=no-altivec @gol -mprototype -mno-prototype @gol -msim -mmvme -mads -myellowknife -memb -msdata @gol @@ -610,8 +610,8 @@ in the following sections. @emph{D30V Options} @gccoptlist{ --mextmem -mextmemory -monchip -mno-asm-optimize -masm-optimize @gol --mbranch-cost=@var{n} -mcond-exec=@var{n}} +-mextmem -mextmemory -monchip -mno-asm-optimize @gol +-masm-optimize -mbranch-cost=@var{n} -mcond-exec=@var{n}} @emph{S/390 and zSeries Options} @gccoptlist{ @@ -670,7 +670,7 @@ in the following sections. -fno-common -fno-ident -fno-gnu-linker @gol -fpcc-struct-return -fpic -fPIC @gol -freg-struct-return -fshared-data -fshort-enums @gol --fshort-double -fvolatile @gol +-fshort-double -fshort-wchar -fvolatile @gol -fvolatile-global -fvolatile-static @gol -fverbose-asm -fpack-struct -fstack-check @gol -fstack-limit-register=@var{reg} -fstack-limit-symbol=@var{sym} @gol @@ -1297,12 +1297,6 @@ than double precision. If you must use @option{-traditional}, but want to use single precision operations when the operands are single precision, use this option. This option has no effect when compiling with ISO or GNU C conventions (the default). - -@item -fshort-wchar -@opindex fshort-wchar -Override the underlying type for @samp{wchar_t} to be @samp{short -unsigned int} instead of the default for the target. This option is -useful for building programs to run under WINE@. @end table @node C++ Dialect Options @@ -9716,7 +9710,8 @@ unwinding from asynchronous events (such as debugger or garbage collector). Return ``short'' @code{struct} and @code{union} values in memory like longer ones, rather than in registers. This convention is less efficient, but it has the advantage of allowing intercallability between -GCC-compiled files and files compiled with other compilers. +GCC-compiled files and files compiled with other compilers, particularly +the Portable C Compiler (pcc). The precise convention for returning structures in memory depends on the target configuration macros. @@ -9724,6 +9719,11 @@ on the target configuration macros. Short structures and unions are those whose size and alignment match that of some integer type. +@strong{Warning:} code compiled with the @option{-fpcc-struct-return} +switch is not binary compatible with code compiled with the +@option{-freg-struct-return} switch. +Use it to conform to a non-default application binary interface. + @item -freg-struct-return @opindex freg-struct-return Return @code{struct} and @code{union} values in registers when possible. @@ -9737,16 +9737,39 @@ defaults to @option{-fpcc-struct-return}, except on targets where GCC is the principal compiler. In those cases, we can choose the standard, and we chose the more efficient register return alternative. +@strong{Warning:} code compiled with the @option{-freg-struct-return} +switch is not binary compatible with code compiled with the +@option{-fpcc-struct-return} switch. +Use it to conform to a non-default application binary interface. + @item -fshort-enums @opindex fshort-enums Allocate to an @code{enum} type only as many bytes as it needs for the declared range of possible values. Specifically, the @code{enum} type will be equivalent to the smallest integer type which has enough room. +@strong{Warning:} the @option{-fshort-enums} switch causes GCC to generate +code that is not binary compatible with code generated without that switch. +Use it to conform to a non-default application binary interface. + @item -fshort-double @opindex fshort-double Use the same size for @code{double} as for @code{float}. +@strong{Warning:} the @option{-fshort-double} switch causes GCC to generate +code that is not binary compatible with code generated without that switch. +Use it to conform to a non-default application binary interface. + +@item -fshort-wchar +@opindex fshort-wchar +Override the underlying type for @samp{wchar_t} to be @samp{short +unsigned int} instead of the default for the target. This option is +useful for building programs to run under WINE@. + +@strong{Warning:} the @option{-fshort-wchar} switch causes GCC to generate +code that is not binary compatible with code generated without that switch. +Use it to conform to a non-default application binary interface. + @item -fshared-data @opindex fshared-data Requests that the data and non-@code{const} variables of this @@ -9888,9 +9911,12 @@ three-way choice. @item -fpack-struct @opindex fpack-struct -Pack all structure members together without holes. Usually you would -not want to use this option, since it makes the code suboptimal, and -the offsets of structure members won't agree with system libraries. +Pack all structure members together without holes. + +@strong{Warning:} the @option{-fpack-struct} switch causes GCC to generate +code that is not binary compatible with code generated without that switch. +Additionally, it makes the code suboptimial. +Use it to conform to a non-default application binary interface. @item -finstrument-functions @opindex finstrument-functions @@ -9987,8 +10013,10 @@ This option and its counterpart, @option{-fno-leading-underscore}, forcibly change the way C symbols are represented in the object file. One use is to help link with legacy assembly code. -Be warned that you should know what you are doing when invoking this -option, and that not all targets provide complete support for it. +@strong{Warning:} the @option{-fleading-underscore} switch causes GCC to +generate code that is not binary compatible with code generated without that +switch. Use it to conform to a non-default application binary interface. +Not all targets provide complete support for this switch. @end table @c man end |
