@c Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
-@c 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
+@c 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
@c This is part of the GCC manual.
@c For copying conditions, see the file gcc.texi.
@ignore
@c man begin COPYRIGHT
Copyright @copyright{} 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
-1998, 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
+1998, 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.2 or
@gccoptlist{-fabi-version=@var{n} -fno-access-control -fcheck-new @gol
-fconserve-space -fno-const-strings @gol
-fno-elide-constructors @gol
--fno-enforce-eh-specs -fexternal-templates @gol
--falt-external-templates @gol
+-fno-enforce-eh-specs @gol
-ffor-scope -fno-for-scope -fno-gnu-keywords @gol
-fno-implicit-templates @gol
-fno-implicit-inline-templates @gol
-fno-nonansi-builtins -fno-operator-names @gol
-fno-optional-diags -fpermissive @gol
-frepo -fno-rtti -fstats -ftemplate-depth-@var{n} @gol
--fuse-cxa-atexit -fvtable-gc -fno-weak -nostdinc++ @gol
+-fuse-cxa-atexit -fno-weak -nostdinc++ @gol
-fno-default-inline -Wabi -Wctor-dtor-privacy @gol
-Wnon-virtual-dtor -Wreorder @gol
-Weffc++ -Wno-deprecated @gol
@item Objective-C Language Options
@xref{Objective-C Dialect Options,,Options Controlling Objective-C Dialect}.
-@gccoptlist{-fconstant-string-class=@var{class-name} @gol
--fgnu-runtime -fnext-runtime -gen-decls @gol
+@gccoptlist{
+-fconstant-string-class=@var{class-name} @gol
+-fgnu-runtime -fnext-runtime @gol
+-fno-nil-receivers @gol
+-fobjc-exceptions @gol
+-freplace-objc-classes @gol
+-fzero-link @gol
+-gen-decls @gol
-Wno-protocol -Wselector -Wundeclared-selector}
@item Language Independent Options
-w -Wextra -Wall -Waggregate-return @gol
-Wcast-align -Wcast-qual -Wchar-subscripts -Wcomment @gol
-Wconversion -Wno-deprecated-declarations @gol
--Wdisabled-optimization -Wno-div-by-zero -Werror @gol
+-Wdisabled-optimization -Wno-div-by-zero -Wendif-labels @gol
+-Werror -Werror-implicit-function-declaration @gol
-Wfloat-equal -Wformat -Wformat=2 @gol
--Wformat-nonliteral -Wformat-security @gol
--Wimplicit -Wimplicit-int @gol
--Wimplicit-function-declaration @gol
--Werror-implicit-function-declaration @gol
--Wimport -Winline -Winvalid-pch -Wno-endif-labels @gol
--Wno-invalid-offsetof @gol
+-Wno-format-extra-args -Wformat-nonliteral @gol
+-Wformat-security -Wformat-y2k @gol
+-Wimplicit -Wimplicit-function-declaration -Wimplicit-int @gol
+-Wimport -Wno-import -Winit-self -Winline @gol
+-Wno-invalid-offsetof -Winvalid-pch @gol
-Wlarger-than-@var{len} -Wlong-long @gol
-Wmain -Wmissing-braces @gol
-Wmissing-format-attribute -Wmissing-noreturn @gol
--Wno-multichar -Wno-format-extra-args -Wno-format-y2k @gol
--Wno-import -Wnonnull -Wpacked -Wpadded @gol
+-Wno-multichar -Wnonnull -Wpacked -Wpadded @gol
-Wparentheses -Wpointer-arith -Wredundant-decls @gol
-Wreturn-type -Wsequence-point -Wshadow @gol
-Wsign-compare -Wstrict-aliasing @gol
@item C-only Warning Options
@gccoptlist{-Wbad-function-cast -Wmissing-declarations @gol
--Wmissing-prototypes -Wnested-externs @gol
--Wstrict-prototypes -Wtraditional}
+-Wmissing-prototypes -Wnested-externs -Wold-style-definition @gol
+-Wstrict-prototypes -Wtraditional @gol
+-Wdeclaration-after-statement}
@item Debugging Options
@xref{Debugging Options,,Options for Debugging Your Program or GCC}.
-fdump-tree-optimized@r{[}-@var{n}@r{]} @gol
-fdump-tree-inlined@r{[}-@var{n}@r{]} @gol
-feliminate-dwarf2-dups -feliminate-unused-debug-types @gol
--fmem-report -fprofile-arcs @gol
+-feliminate-unused-debug-symbols -fmem-report -fprofile-arcs @gol
-frandom-seed=@var{string} -fsched-verbose=@var{n} @gol
-ftest-coverage -ftime-report @gol
--g -g@var{level} -gcoff -gdwarf -gdwarf-1 -gdwarf-1+ -gdwarf-2 @gol
+-g -g@var{level} -gcoff -gdwarf-2 @gol
-ggdb -gstabs -gstabs+ -gvms -gxcoff -gxcoff+ @gol
-p -pg -print-file-name=@var{library} -print-libgcc-file-name @gol
-print-multi-directory -print-multi-lib @gol
@xref{Optimize Options,,Options that Control Optimization}.
@gccoptlist{-falign-functions=@var{n} -falign-jumps=@var{n} @gol
-falign-labels=@var{n} -falign-loops=@var{n} @gol
--fbranch-probabilities -fbranch-target-load-optimize @gol
--fbranch-target-load-optimize2 -fcaller-saves -fcprop-registers @gol
+-fbranch-probabilities -fprofile-values -fvpt -fbranch-target-load-optimize @gol
+-fbranch-target-load-optimize2 -fbtr-bb-exclusive @gol
+-fcaller-saves -fcprop-registers @gol
-fcse-follow-jumps -fcse-skip-blocks -fdata-sections @gol
-fdelayed-branch -fdelete-null-pointer-checks @gol
-fexpensive-optimizations -ffast-math -ffloat-store @gol
-fforce-addr -fforce-mem -ffunction-sections @gol
--fgcse -fgcse-lm -fgcse-sm -floop-optimize -fcrossjumping @gol
--fif-conversion -fif-conversion2 @gol
+-fgcse -fgcse-lm -fgcse-sm -fgcse-las -floop-optimize @gol
+-fcrossjumping -fif-conversion -fif-conversion2 @gol
-finline-functions -finline-limit=@var{n} -fkeep-inline-functions @gol
-fkeep-static-consts -fmerge-constants -fmerge-all-constants @gol
-fmove-all-movables -fnew-ra -fno-branch-count-reg @gol
-fno-trapping-math -fno-zero-initialized-in-bss @gol
-fomit-frame-pointer -foptimize-register-move @gol
-foptimize-sibling-calls -fprefetch-loop-arrays @gol
+-fprofile-generate -fprofile-use @gol
-freduce-all-givs -fregmove -frename-registers @gol
-freorder-blocks -freorder-functions @gol
-frerun-cse-after-loop -frerun-loop-opt @gol
--fschedule-insns -fschedule-insns2 @gol
+-frounding-math -fschedule-insns -fschedule-insns2 @gol
-fno-sched-interblock -fno-sched-spec -fsched-spec-load @gol
--fsched-spec-load-dangerous -fsched2-use-superblocks @gol
+-fsched-spec-load-dangerous @gol
+-fsched-stalled-insns=@var{n} -sched-stalled-insns-dep=@var{n} @gol
+-fsched2-use-superblocks @gol
-fsched2-use-traces -fsignaling-nans @gol
--fsingle-precision-constant -fssa -fssa-ccp -fssa-dce @gol
+-fsingle-precision-constant @gol
-fstrength-reduce -fstrict-aliasing -ftracer -fthread-jumps @gol
-funroll-all-loops -funroll-loops -fpeel-loops @gol
-funswitch-loops -fold-unroll-loops -fold-unroll-all-loops @gol
-include @var{file} -imacros @var{file} @gol
-iprefix @var{file} -iwithprefix @var{dir} @gol
-iwithprefixbefore @var{dir} -isystem @var{dir} @gol
--M -MM -MF -MG -MP -MQ -MT -nostdinc -P -remap @gol
+-M -MM -MF -MG -MP -MQ -MT -nostdinc @gol
+-P -fworking-directory -remap @gol
-trigraphs -undef -U@var{macro} -Wp,@var{option} @gol
-Xpreprocessor @var{option}}
@gccoptlist{-m68000 -m68020 -m68020-40 -m68020-60 -m68030 -m68040 @gol
-m68060 -mcpu32 -m5200 -m68881 -mbitfield -mc68000 -mc68020 @gol
-mnobitfield -mrtd -mshort -msoft-float -mpcrel @gol
--malign-int -mstrict-align}
+-malign-int -mstrict-align -msep-data -mno-sep-data @gol
+-mshared-library-id=n -mid-shared-library -mno-id-shared-library}
@emph{M68hc1x Options}
@gccoptlist{-m6811 -m6812 -m68hc11 -m68hc12 -m68hcs12 @gol
-mapp-regs -mbroken-saverestore -mcypress @gol
-mfaster-structs -mflat @gol
-mfpu -mhard-float -mhard-quad-float @gol
--mimpure-text -mlive-g0 -mno-app-regs @gol
+-mimpure-text -mlittle-endian -mlive-g0 -mno-app-regs @gol
-mno-faster-structs -mno-flat -mno-fpu @gol
-mno-impure-text -mno-stack-bias -mno-unaligned-doubles @gol
-msoft-float -msoft-quad-float -msparclite -mstack-bias @gol
-mtpcs-frame -mtpcs-leaf-frame @gol
-mcaller-super-interworking -mcallee-super-interworking}
-@emph{MN10200 Options}
-@gccoptlist{-mrelax}
-
@emph{MN10300 Options}
@gccoptlist{-mmult-bug -mno-mult-bug @gol
-mam33 -mno-am33 @gol
+-mam33-2 -mno-am33-2 @gol
-mno-crt0 -mrelax}
@emph{M32R/D Options}
-@gccoptlist{-m32rx -m32r -mcode-model=@var{model-type} @gol
--msdata=@var{sdata-type} -G @var{num}}
-
-@emph{M88K Options}
-@gccoptlist{-m88000 -m88100 -m88110 -mbig-pic @gol
--mcheck-zero-division -mhandle-large-shift @gol
--midentify-revision -mno-check-zero-division @gol
--mno-ocs-debug-info -mno-ocs-frame-position @gol
--mno-optimize-arg-area -mno-serialize-volatile @gol
--mno-underscores -mocs-debug-info @gol
--mocs-frame-position -moptimize-arg-area @gol
--mserialize-volatile -mshort-data-@var{num} -msvr3 @gol
--msvr4 -mtrap-large-shift -muse-div-instruction @gol
--mversion-03.00 -mwarn-passed-structs}
+@gccoptlist{-m32r2 -m32rx -m32r @gol
+-mdebug @gol
+-malign-loops -mno-align-loops @gol
+-missue-rate=@var{number} @gol
+-mbranch-cost=@var{number} @gol
+-mmodel=@var{code-size-model-type} @gol
+-msdata=@var{sdata-type} @gol
+-mno-flush-func -mflush-func=@var{name} @gol
+-mno-flush-trap -mflush-trap=@var{number} @gol
+-G @var{num}}
@emph{RS/6000 and PowerPC Options}
@gccoptlist{-mcpu=@var{cpu-type} @gol
-mno-relocatable -mrelocatable-lib -mno-relocatable-lib @gol
-mtoc -mno-toc -mlittle -mlittle-endian -mbig -mbig-endian @gol
-mdynamic-no-pic @gol
+-mprioritize-restricted-insns=@var{priority} @gol
+-msched-costly-dep=@var{dependence_type} @gol
+-minsert-sched-nops=@var{scheme} @gol
-mcall-sysv -mcall-netbsd @gol
-maix-struct-return -msvr4-struct-return @gol
-mabi=altivec -mabi=no-altivec @gol
-force_flat_namespace -headerpad_max_install_names @gol
-image_base -init -install_name -keep_private_externs @gol
-multi_module -multiply_defined -multiply_defined_unused @gol
--noall_load -nomultidefs -noprebind -noseglinkedit @gol
+-noall_load -nofixprebinding -nomultidefs -noprebind -noseglinkedit @gol
-pagezero_size -prebind -prebind_all_twolevel_modules @gol
-private_bundle -read_only_relocs -sectalign @gol
-sectobjectsymbols -whyload -seg1addr @gol
-unexported_symbols_list -weak_reference_mismatches @gol
-whatsloaded}
-@emph{RT Options}
-@gccoptlist{-mcall-lib-mul -mfp-arg-in-fpregs -mfp-arg-in-gregs @gol
--mfull-fp-blocks -mhc-struct-return -min-line-mul @gol
--mminimum-fp-blocks -mnohc-struct-return}
-
@emph{MIPS Options}
-@gccoptlist{-mabicalls -march=@var{cpu-type} -mtune=@var{cpu=type} @gol
--mcpu=@var{cpu-type} -membedded-data -muninit-const-in-rodata @gol
--membedded-pic -mfp32 -mfp64 -mfused-madd -mno-fused-madd @gol
--mgas -mgp32 -mgp64 @gol
--mgpopt -mhalf-pic -mhard-float -mint64 -mips1 @gol
--mips2 -mips3 -mips4 -mips32 -mips32r2 -mips64 @gol
--mlong64 -mlong32 -mlong-calls -mmemcpy @gol
--mmips-as -mmips-tfile -mno-abicalls @gol
--mno-embedded-data -mno-uninit-const-in-rodata @gol
--mno-embedded-pic -mno-gpopt -mno-long-calls @gol
--mno-memcpy -mno-mips-tfile -mno-rnames -mno-stats @gol
--mrnames -msoft-float @gol
--m4650 -msingle-float -mmad @gol
--EL -EB -G @var{num} -nocpp @gol
--mabi=32 -mabi=n32 -mabi=64 -mabi=eabi -mabi-fake-default @gol
--mfix7000 -mno-crt0 -mflush-func=@var{func} -mno-flush-func @gol
--mbranch-likely -mno-branch-likely}
+@gccoptlist{-EL -EB -march=@var{arch} -mtune=@var{arch} @gol
+-mips1 -mips2 -mips3 -mips4 -mips32 -mips32r2 -mips64 @gol
+-mips16 -mno-mips16 -mabi=@var{abi} -mabicalls -mno-abicalls @gol
+-mxgot -mno-xgot -membedded-pic -mno-embedded-pic @gol
+-mgp32 -mgp64 -mfp32 -mfp64 -mhard-float -msoft-float @gol
+-msingle-float -mdouble-float -mint64 -mlong64 -mlong32 @gol
+-G@var{num} -membedded-data -mno-embedded-data @gol
+-muninit-const-in-rodata -mno-uninit-const-in-rodata @gol
+-msplit-addresses -mno-split-addresses @gol
+-mexplicit-relocs -mno-explicit-relocs @gol
+-mrnames -mno-rnames @gol
+-mcheck-zero-division -mno-check-zero-division @gol
+-mmemcpy -mno-memcpy -mlong-calls -mno-long-calls @gol
+-mmad -mno-mad -mfused-madd -mno-fused-madd -nocpp @gol
+-mfix-sb1 -mno-fix-sb1 -mflush-func=@var{func} @gol
+-mno-flush-func -mbranch-likely -mno-branch-likely}
@emph{i386 and x86-64 Options}
@gccoptlist{-mtune=@var{cpu-type} -march=@var{cpu-type} @gol
-mno-fp-ret-in-387 -msoft-float -msvr3-shlib @gol
-mno-wide-multiply -mrtd -malign-double @gol
-mpreferred-stack-boundary=@var{num} @gol
--mmmx -msse -msse2 -m3dnow @gol
+-mmmx -msse -msse2 -mpni -m3dnow @gol
-mthreads -mno-align-stringops -minline-all-stringops @gol
-mpush-args -maccumulate-outgoing-args -m128bit-long-double @gol
-m96bit-long-double -mregparm=@var{num} -momit-leaf-frame-pointer @gol
-mtda=@var{n} -msda=@var{n} -mzda=@var{n} @gol
-mapp-regs -mno-app-regs @gol
-mdisable-callt -mno-disable-callt @gol
+-mv850e1 @gol
-mv850e @gol
-mv850 -mbig-switch}
@gccoptlist{-mtune=@var{cpu-type} -march=@var{cpu-type} @gol
-mhard-float -msoft-float -mbackchain -mno-backchain @gol
-msmall-exec -mno-small-exec -mmvcle -mno-mvcle @gol
--m64 -m31 -mdebug -mno-debug -mesa -mzarch}
+-m64 -m31 -mdebug -mno-debug -mesa -mzarch -mfused-madd -mno-fused-madd}
@emph{CRIS Options}
@gccoptlist{-mcpu=@var{cpu} -march=@var{cpu} -mtune=@var{cpu} @gol
@gccoptlist{-msim}
@emph{Xtensa Options}
-@gccoptlist{-mbig-endian -mlittle-endian @gol
--mdensity -mno-density @gol
--mconst16 -mno-const16 @gol
--mabs -mno-abs @gol
--maddx -mno-addx @gol
--mmac16 -mno-mac16 @gol
--mmul16 -mno-mul16 @gol
--mmul32 -mno-mul32 @gol
--mnsa -mno-nsa @gol
--mminmax -mno-minmax @gol
--msext -mno-sext @gol
--mbooleans -mno-booleans @gol
--mhard-float -msoft-float @gol
+@gccoptlist{-mconst16 -mno-const16 @gol
-mfused-madd -mno-fused-madd @gol
-mtext-section-literals -mno-text-section-literals @gol
-mtarget-align -mno-target-align @gol
-fnon-call-exceptions -funwind-tables @gol
-fasynchronous-unwind-tables @gol
-finhibit-size-directive -finstrument-functions @gol
--fno-common -fno-ident -fno-gnu-linker @gol
+-fno-common -fno-ident @gol
-fpcc-struct-return -fpic -fPIC -fpie -fPIE @gol
-freg-struct-return -fshared-data -fshort-enums @gol
-fshort-double -fshort-wchar @gol
@section Options Controlling the Kind of Output
Compilation can involve up to four stages: preprocessing, compilation
-proper, assembly and linking, always in that order. The first three
-stages apply to an individual source file, and end by producing an
-object file; linking combines all the object files (those newly
-compiled, and those specified as input) into an executable file.
+proper, assembly and linking, always in that order. GCC is capable of
+preprocessing and compiling several files either into several
+assembler input files, or into one assembler input file; then each
+assembler input file produces an object file, and linking combines all
+the object files (those newly compiled, and those specified as input)
+into an executable file.
@cindex file name suffix
For any given input file, the file name suffix determines what kind of
(rather than letting the compiler choose a default based on the file
name suffix). This option applies to all following input files until
the next @option{-x} option. Possible values for @var{language} are:
-@example
+@smallexample
c c-header cpp-output
c++ c++-header c++-cpp-output
objective-c objective-c-header objc-cpp-output
f77 f77-cpp-input ratfor
java
treelang
-@end example
+@end smallexample
@item -x none
Turn off any specification of a language, so that subsequent files are
sort of output is being produced, whether it be an executable file,
an object file, an assembler file or preprocessed C code.
-Since only one output file can be specified, it does not make sense to
-use @option{-o} when compiling more than one input file, unless you are
-producing an executable file as output.
+If you specify @option{-o} when compiling more than one input file, or
+you are producing an executable file as output, all the source files
+on the command line will be compiled at once.
If @option{-o} is not specified, the default is to put an executable file
in @file{a.out}, the object file for @file{@var{source}.@var{suffix}} in
Default, ISO C90 plus GNU extensions (including some C99 features).
@item gnu99
-@item gnu9x
+@itemx gnu9x
ISO C99 plus GNU extensions. When ISO C99 is fully implemented in GCC,
this will become the default. The name @samp{gnu9x} is deprecated.
Writing into string constants is a very bad idea; ``constants'' should
be constant.
+
+This option is deprecated.
@end table
@node C++ Dialect Options
regardless of what language your program is in. For example, you
might compile a file @code{firstClass.C} like this:
-@example
+@smallexample
g++ -g -frepo -O -c firstClass.C
-@end example
+@end smallexample
@noindent
In this example, only @option{-frepo} is an option meant
@item -fabi-version=@var{n}
@opindex fabi-version
-Use version @var{n} of the C++ ABI. Version 1 is the version of the C++
-ABI that first appeared in G++ 3.2. Version 0 will always be the
-version that conforms most closely to the C++ ABI specification.
-Therefore, the ABI obtained using version 0 will change as ABI bugs are
-fixed.
+Use version @var{n} of the C++ ABI. Version 2 is the version of the
+C++ ABI that first appeared in G++ 3.4. Version 1 is the version of
+the C++ ABI that first appeared in G++ 3.2. Version 0 will always be
+the version that conforms most closely to the C++ ABI specification.
+Therefore, the ABI obtained using version 0 will change as ABI bugs
+are fixed.
The default is version 1.
size in production builds, much like defining @samp{NDEBUG}. The compiler
will still optimize based on the exception specifications.
-@item -fexternal-templates
-@opindex fexternal-templates
-
-Cause @samp{#pragma interface} and @samp{implementation} to apply to
-template instantiation; template instances are emitted or not according
-to the location of the template definition. @xref{Template
-Instantiation}, for more information.
-
-This option is deprecated.
-
-@item -falt-external-templates
-@opindex falt-external-templates
-Similar to @option{-fexternal-templates}, but template instances are
-emitted or not according to the place where they are first instantiated.
-@xref{Template Instantiation}, for more information.
-
-This option is deprecated.
-
@item -ffor-scope
@itemx -fno-for-scope
@opindex ffor-scope
@item -fpermissive
@opindex fpermissive
-Downgrade messages about nonconformant code from errors to warnings. By
-default, G++ effectively sets @option{-pedantic-errors} without
-@option{-pedantic}; this option reverses that. This behavior and this
-option are superseded by @option{-pedantic}, which works as it does for GNU C@.
+Downgrade some diagnostics about nonconformant code from errors to
+warnings. Thus, using @option{-fpermissive} will allow some
+nonconforming code to compile.
@item -frepo
@opindex frepo
destructors, but will only work if your C library supports
@code{__cxa_atexit}.
-@item -fvtable-gc
-@opindex fvtable-gc
-Emit special relocations for vtables and virtual function references
-so that the linker can identify unused virtual functions and zero out
-vtable slots that refer to them. This is most useful with
-@option{-ffunction-sections} and @option{-Wl,--gc-sections}, in order to
-also discard the functions themselves.
-
-This optimization requires GNU as and GNU ld. Not all systems support
-this option. @option{-Wl,--gc-sections} is ignored without @option{-static}.
-
@item -fno-weak
@opindex fno-weak
Do not use weak symbol support, even if it is provided by the linker.
@opindex Wabi
Warn when G++ generates code that is probably not compatible with the
vendor-neutral C++ ABI. Although an effort has been made to warn about
-all such cases, there are probably some cases that are not warned about,
+all such cases, there are probably some cases that are not warned about,
even though G++ is generating incompatible code. There may also be
cases where warnings are emitted even though the code that is generated
will be compatible.
@noindent
In this case, G++ will place @code{B::f2} into the same byte
-as@code{A::f1}; other compilers will not. You can avoid this problem
+as@code{A::f1}; other compilers will not. You can avoid this problem
by explicitly padding @code{A} so that its size is a multiple of the
byte size on your platform; that will cause G++ and other compilers to
layout @code{B} identically.
@item
Empty classes can be placed at incorrect offsets. For example:
-
+
@smallexample
struct A @{@};
@item -Wctor-dtor-privacy @r{(C++ only)}
@opindex Wctor-dtor-privacy
-Warn when a class seems unusable, because all the constructors or
-destructors in a class are private and the class has no friends or
+Warn when a class seems unusable because all the constructors or
+destructors in that class are private, and it has neither friends nor
public static member functions.
@item -Wnon-virtual-dtor @r{(C++ only)}
@opindex Wnon-virtual-dtor
-Warn when a class declares a non-virtual destructor that should probably
-be virtual, because it looks like the class will be used polymorphically.
+Warn when a class appears to be polymorphic, thereby requiring a virtual
+destructor, yet it declares a non-virtual one.
This warning is enabled by @option{-Wall}.
@item -Wreorder @r{(C++ only)}
@};
@end smallexample
-Here the compiler will warn that the member initializers for @samp{i}
-and @samp{j} will be rearranged to match the declaration order of the
-members. This warning is enabled by @option{-Wall}.
+The compiler will rearrange the member initializers for @samp{i}
+and @samp{j} to match the declaration order of the members, emitting
+a warning to that effect. This warning is enabled by @option{-Wall}.
@end table
The following @option{-W@dots{}} options are not affected by @option{-Wall}.
@end itemize
-and about violations of the following style guidelines from Scott Meyers'
-@cite{More Effective C++} book:
+Also warn about violations of the following style guidelines from
+Scott Meyers' @cite{More Effective C++} book:
@itemize @bullet
@item
@end itemize
-If you use this option, you should be aware that the standard library
-headers do not obey all of these guidelines; you can use @samp{grep -v}
+When selecting this option, be aware that the standard library
+headers do not obey all of these guidelines; use @samp{grep -v}
to filter out those warnings.
@item -Wno-deprecated @r{(C++ only)}
@item -Wno-non-template-friend @r{(C++ only)}
@opindex Wno-non-template-friend
Disable warnings when non-templatized friend functions are declared
-within a template. With the advent of explicit template specification
+within a template. Since the advent of explicit template specification
support in G++, if the name of the friend is an unqualified-id (i.e.,
@samp{friend foo(int)}), the C++ language specification demands that the
friend declare or define an ordinary, nontemplate function. (Section
could be interpreted as a particular specialization of a templatized
function. Because this non-conforming behavior is no longer the default
behavior for G++, @option{-Wnon-template-friend} allows the compiler to
-check existing code for potential trouble spots, and is on by default.
+check existing code for potential trouble spots and is on by default.
This new compiler behavior can be turned off with
@option{-Wno-non-template-friend} which keeps the conformant compiler code
but disables the helpful warning.
Warn if an old-style (C-style) cast to a non-void type is used within
a C++ program. The new-style casts (@samp{static_cast},
@samp{reinterpret_cast}, and @samp{const_cast}) are less vulnerable to
-unintended effects, and much easier to grep for.
+unintended effects and much easier to search for.
@item -Woverloaded-virtual @r{(C++ only)}
@opindex Woverloaded-virtual
@end smallexample
the @code{A} class version of @code{f} is hidden in @code{B}, and code
-like this:
+like:
@smallexample
B* b;
@item -Wsign-promo @r{(C++ only)}
@opindex Wsign-promo
Warn when overload resolution chooses a promotion from unsigned or
-enumeral type to a signed type over a conversion to an unsigned type of
+enumeral type to a signed type, over a conversion to an unsigned type of
the same size. Previous versions of G++ would try to preserve
unsignedness, but the standard mandates the current behavior.
@cindex compiler options, Objective-C
@cindex Objective-C options, command line
@cindex options, Objective-C
+(NOTE: This manual does not describe the Objective-C language itself. See
+@w{@uref{http://gcc.gnu.org/readings.html}} for references.)
+
This section describes the command-line options that are only meaningful
-for Objective-C programs; but you can also use most of the GNU compiler
+for Objective-C programs, but you can also use most of the GNU compiler
options regardless of what language your program is in. For example,
you might compile a file @code{some_class.m} like this:
-@example
+@smallexample
gcc -g -fgnu-runtime -O -c some_class.m
-@end example
+@end smallexample
@noindent
-In this example, only @option{-fgnu-runtime} is an option meant only for
+In this example, @option{-fgnu-runtime} is an option meant only for
Objective-C programs; you can use the other options with any language
supported by GCC@.
@opindex fconstant-string-class
Use @var{class-name} as the name of the class to instantiate for each
literal string specified with the syntax @code{@@"@dots{}"}. The default
-class name is @code{NXConstantString}.
+class name is @code{NXConstantString} if the GNU runtime is being used, and
+@code{NSConstantString} if the NeXT runtime is being used (see below). The
+@option{-fconstant-cfstrings} option, if also present, will override the
+@option{-fconstant-string-class} setting and cause @code{@@"@dots{}"} literals
+to be laid out as constant CoreFoundation strings.
@item -fgnu-runtime
@opindex fgnu-runtime
@code{__NEXT_RUNTIME__} is predefined if (and only if) this option is
used.
+@item -fno-nil-receivers
+@opindex -fno-nil-receivers
+Assume that all Objective-C message dispatches (e.g.,
+@code{[receiver message:arg]}) in this translation unit ensure that the receiver
+is not @code{nil}. This allows for more efficient entry points in the runtime to be
+used. Currently, this option is only available in conjunction with
+the NeXT runtime on Mac OS X 10.3 and later.
+
+@item -fobjc-exceptions
+@opindex -fobjc-exceptions
+Enable syntactic support for structured exception handling in Objective-C,
+similar to what is offered by C++ and Java. Currently, this option is only
+available in conjunction with the NeXT runtime on Mac OS X 10.3 and later.
+
+@smallexample
+ @@try @{
+ @dots{}
+ @@throw expr;
+ @dots{}
+ @}
+ @@catch (AnObjCClass *exc) @{
+ @dots{}
+ @@throw expr;
+ @dots{}
+ @@throw;
+ @dots{}
+ @}
+ @@catch (AnotherClass *exc) @{
+ @dots{}
+ @}
+ @@catch (id allOthers) @{
+ @dots{}
+ @}
+ @@finally @{
+ @dots{}
+ @@throw expr;
+ @dots{}
+ @}
+@end smallexample
+
+The @code{@@throw} statement may appear anywhere in an Objective-C or
+Objective-C++ program; when used inside of a @code{@@catch} block, the
+@code{@@throw} may appear without an argument (as shown above), in which case
+the object caught by the @code{@@catch} will be rethrown.
+
+Note that only (pointers to) Objective-C objects may be thrown and
+caught using this scheme. When an object is thrown, it will be caught
+by the nearest @code{@@catch} clause capable of handling objects of that type,
+analogously to how @code{catch} blocks work in C++ and Java. A
+@code{@@catch(id @dots{})} clause (as shown above) may also be provided to catch
+any and all Objective-C exceptions not caught by previous @code{@@catch}
+clauses (if any).
+
+The @code{@@finally} clause, if present, will be executed upon exit from the
+immediately preceding @code{@@try @dots{} @@catch} section. This will happen
+regardless of whether any exceptions are thrown, caught or rethrown
+inside the @code{@@try @dots{} @@catch} section, analogously to the behavior
+of the @code{finally} clause in Java.
+
+There are several caveats to using the new exception mechanism:
+
+@itemize @bullet
+@item
+Although currently designed to be binary compatible with @code{NS_HANDLER}-style
+idioms provided by the @code{NSException} class, the new
+exceptions can only be used on Mac OS X 10.3 (Panther) and later
+systems, due to additional functionality needed in the (NeXT) Objective-C
+runtime.
+
+@item
+As mentioned above, the new exceptions do not support handling
+types other than Objective-C objects. Furthermore, when used from
+Objective-C++, the Objective-C exception model does not interoperate with C++
+exceptions at this time. This means you cannot @code{@@throw} an exception
+from Objective-C and @code{catch} it in C++, or vice versa
+(i.e., @code{throw @dots{} @@catch}).
+@end itemize
+
+The @option{-fobjc-exceptions} switch also enables the use of synchronization
+blocks for thread-safe execution:
+
+@smallexample
+ @@synchronized (ObjCClass *guard) @{
+ @dots{}
+ @}
+@end smallexample
+
+Upon entering the @code{@@synchronized} block, a thread of execution shall
+first check whether a lock has been placed on the corresponding @code{guard}
+object by another thread. If it has, the current thread shall wait until
+the other thread relinquishes its lock. Once @code{guard} becomes available,
+the current thread will place its own lock on it, execute the code contained in
+the @code{@@synchronized} block, and finally relinquish the lock (thereby
+making @code{guard} available to other threads).
+
+Unlike Java, Objective-C does not allow for entire methods to be marked
+@code{@@synchronized}. Note that throwing exceptions out of
+@code{@@synchronized} blocks is allowed, and will cause the guarding object
+to be unlocked properly.
+
+@item -freplace-objc-classes
+@opindex -freplace-objc-classes
+Emit a special marker instructing @command{ld(1)} not to statically link in
+the resulting object file, and allow @command{dyld(1)} to load it in at
+run time instead. This is used in conjunction with the Fix-and-Continue
+debugging mode, where the object file in question may be recompiled and
+dynamically reloaded in the course of program execution, without the need
+to restart the program itself. Currently, Fix-and-Continue functionality
+is only available in conjunction with the NeXT runtime on Mac OS X 10.3
+and later.
+
+@item -fzero-link
+@opindex -fzero-link
+When compiling for the NeXT runtime, the compiler ordinarily replaces calls
+to @code{objc_getClass("@dots{}")} (when the name of the class is known at
+compile time) with static class references that get initialized at load time,
+which improves run-time performance. Specifying the @option{-fzero-link} flag
+suppresses this behavior and causes calls to @code{objc_getClass("@dots{}")}
+to be retained. This is useful in Zero-Link debugging mode, since it allows
+for individual class implementations to be modified during program execution.
+
@item -gen-decls
@opindex gen-decls
Dump interface declarations for all classes seen in the source file to a
Warn if multiple methods of different types for the same selector are
found during compilation. The check is performed on the list of methods
in the final stage of compilation. Additionally, a check is performed
-that for each selector appearing in a @code{@@selector(@dots{})}
-expression, a corresponding method with that selector has been found
+for each selector appearing in a @code{@@selector(@dots{})}
+expression, and a corresponding method for that selector has been found
during compilation. Because these checks scan the method table only at
the end of compilation, these warnings are not produced if the final
stage of compilation is not reached, for example because an error is
@opindex Wundeclared-selector
Warn if a @code{@@selector(@dots{})} expression referring to an
undeclared selector is found. A selector is considered undeclared if no
-method with that name has been declared (explicitly, in an
-@code{@@interface} or @code{@@protocol} declaration, or implicitly, in
-an @code{@@implementation} section) before the
-@code{@@selector(@dots{})} expression. This option always performs its
-checks as soon as a @code{@@selector(@dots{})} expression is found
-(while @code{-Wselector} only performs its checks in the final stage of
-compilation), and so additionally enforces the coding style convention
+method with that name has been declared before the
+@code{@@selector(@dots{})} expression, either explicitly in an
+@code{@@interface} or @code{@@protocol} declaration, or implicitly in
+an @code{@@implementation} section. This option always performs its
+checks as soon as a @code{@@selector(@dots{})} expression is found,
+while @code{-Wselector} only performs its checks in the final stage of
+compilation. This also enforces the coding style convention
that methods and selectors must be declared before being used.
-@c not documented because only avail via -Wp
-@c @item -print-objc-runtime-info
+@item -print-objc-runtime-info
+@opindex -print-objc-runtime-info
+Generate C header describing the largest structure that is passed by
+value, if any.
@end table
several functions, @option{-Wformat} also implies @option{-Wnonnull}.
@option{-Wformat} is included in @option{-Wall}. For more control over some
-aspects of format checking, the options @option{-Wno-format-y2k},
+aspects of format checking, the options @option{-Wformat-y2k},
@option{-Wno-format-extra-args}, @option{-Wno-format-zero-length},
@option{-Wformat-nonliteral}, @option{-Wformat-security}, and
@option{-Wformat=2} are available, but are not included in @option{-Wall}.
-@item -Wno-format-y2k
-@opindex Wno-format-y2k
-If @option{-Wformat} is specified, do not warn about @code{strftime}
+@item -Wformat-y2k
+@opindex Wformat-y2k
+If @option{-Wformat} is specified, also warn about @code{strftime}
formats which may yield only a two-digit year.
@item -Wno-format-extra-args
@opindex Wformat=2
Enable @option{-Wformat} plus format checks not included in
@option{-Wformat}. Currently equivalent to @samp{-Wformat
--Wformat-nonliteral -Wformat-security}.
+-Wformat-nonliteral -Wformat-security -Wformat-y2k}.
@item -Wnonnull
@opindex Wnonnull
-Enable warning about passing a null pointer for arguments marked as
+Warn about passing a null pointer for arguments marked as
requiring a non-null value by the @code{nonnull} function attribute.
@option{-Wnonnull} is included in @option{-Wall} and @option{-Wformat}. It
can be disabled with the @option{-Wno-nonnull} option.
+@item -Winit-self @r{(C, C++, and Objective-C only)}
+@opindex Winit-self
+Warn about uninitialized variables which are initialized with themselves.
+Note this option can only be used with the @option{-Wuninitialized} option,
+which in turn only works with @option{-O1} and above.
+
+For example, GCC will warn about @code{i} being uninitialized in the
+following snippet only when @option{-Winit-self} has been specified:
+@smallexample
+@group
+int f()
+@{
+ int i = i;
+ return i;
+@}
+@end group
+@end smallexample
+
@item -Wimplicit-int
@opindex Wimplicit-int
Warn when a declaration does not specify a type.
when optimizing. If you don't specify @option{-O}, you simply won't
get these warnings.
+If you want to warn about code which uses the uninitialized value of the
+variable in its own initializer, use the @option{-Winit-self} option.
+
These warnings occur only for variables that are candidates for
register allocation. Therefore, they do not occur for a variable that
is declared @code{volatile}, or whose address is taken, or whose size
traditional C compatibility.
@end itemize
+@item -Wdeclaration-after-statement @r{(C only)}
+@opindex Wdeclaration-after-statement
+Warn when a declaration is found after a statement in a block. This
+construct, known from C++, was introduced with ISO C99 and is by default
+allowed in GCC@. It is not supported by ISO C90 and was not supported by
+GCC versions before GCC 3.0. @xref{Mixed Declarations}.
+
@item -Wundef
@opindex Wundef
Warn if an undefined identifier is evaluated in an @samp{#if} directive.
a warning if preceded by a declaration which specifies the argument
types.)
+@item -Wold-style-definition @r{(C only)}
+@opindex Wold-style-definition
+Warn if an old-style function definition is used. A warning is given
+even if there is a previous prototype.
+
@item -Wmissing-prototypes @r{(C only)}
@opindex Wmissing-prototypes
Warn if a global function is defined without a previous prototype
@opindex Winline
Warn if a function can not be inlined and it was declared as inline.
Even with this option, the compiler will not warn about failures to
-inline functions declared in system headers.
+inline functions declared in system headers.
The compiler uses a variety of heuristics to determine whether or not
to inline a function. For example, the compiler takes into account
crash or
refuse to read the program. If you want to control for certain whether
to generate the extra information, use @option{-gstabs+}, @option{-gstabs},
-@option{-gxcoff+}, @option{-gxcoff}, @option{-gdwarf-1+}, @option{-gdwarf-1},
-or @option{-gvms} (see below).
+@option{-gxcoff+}, @option{-gxcoff}, or @option{-gvms} (see below).
Unlike most other C compilers, GCC allows you to use @option{-g} with
@option{-O}. The shortcuts taken by optimized code may occasionally
produces stabs debugging output which is not understood by DBX or SDB@.
On System V Release 4 systems this option requires the GNU assembler.
+@item -feliminate-unused-debug-symbols
+@opindex feliminate-unused-debug-symbols
+Produce debugging information in stabs format (if that is supported),
+for only symbols that are actually used.
+
@item -gstabs+
@opindex gstabs+
Produce debugging information in stabs format (if that is supported),
refuse to read the program, and may cause assemblers other than the GNU
assembler (GAS) to fail with an error.
-@item -gdwarf
-@opindex gdwarf
-Produce debugging information in DWARF version 1 format (if that is
-supported). This is the format used by SDB on most System V Release 4
-systems.
-
-This option is deprecated.
-
-@item -gdwarf+
-@opindex gdwarf+
-Produce debugging information in DWARF version 1 format (if that is
-supported), using GNU extensions understood only by the GNU debugger
-(GDB)@. The use of these extensions is likely to make other debuggers
-crash or refuse to read the program.
-
-This option is deprecated.
-
@item -gdwarf-2
@opindex gdwarf-2
Produce debugging information in DWARF version 2 format (if that is
you use @option{-g3}.
Note that in order to avoid confusion between DWARF1 debug level 2,
-and DWARF2, neither @option{-gdwarf} nor @option{-gdwarf-2} accept
-a concatenated debug level. Instead use an additional @option{-g@var{level}}
-option to change the debug level for DWARF1 or DWARF2.
+and DWARF2 @option{-gdwarf-2} does not accept a concatenated debug
+level. Instead use an additional @option{-g@var{level}} option to
+change the debug level for DWARF2.
@item -feliminate-dwarf2-dups
@opindex feliminate-dwarf2-dups
execution the program records how many times each branch and call is
executed and how many times it is taken or returns. When the compiled
program exits it saves this data to a file called
-@file{@var{auxname}.da} for each source file. The data may be used for
+@file{@var{auxname}.gcda} for each source file. The data may be used for
profile-directed optimizations (@option{-fbranch-probabilities}), or for
test coverage analysis (@option{-ftest-coverage}). Each object file's
@var{auxname} is generated from the name of the output file, if
explicitly specified and it is not the final executable, otherwise it is
the basename of the source file. In both cases any suffix is removed
-(e.g. @file{foo.da} for input file @file{dir/foo.c}, or
-@file{dir/foo.da} for output file specified as @option{-o dir/foo.o}).
+(e.g. @file{foo.gcda} for input file @file{dir/foo.c}, or
+@file{dir/foo.gcda} for output file specified as @option{-o dir/foo.o}).
@itemize
@item
For test coverage analysis, use @command{gcov} to produce human readable
-information from the @file{.bbg} and @file{.da} files. Refer to the
+information from the @file{.gcno} and @file{.gcda} files. Refer to the
@command{gcov} documentation for further information.
@end itemize
@need 2000
@item -ftest-coverage
@opindex ftest-coverage
-Produce a graph file that the @command{gcov} code-coverage utility
+Produce a notes file that the @command{gcov} code-coverage utility
(@pxref{Gcov,, @command{gcov}---a Test Coverage Program}) can use to
-show program coverage. Each source file's data file is called
-@file{@var{auxname}.bbg}. Refer to the @option{-fprofile-arcs} option
+show program coverage. Each source file's note file is called
+@file{@var{auxname}.gcno}. Refer to the @option{-fprofile-arcs} option
above for a description of @var{auxname} and instructions on how to
generate test coverage data. Coverage data will match the source files
more closely, if you do not optimize.
the @var{dumpname}. @var{dumpname} is generated from the name of the
output file, if explicitly specified and it is not an executable,
otherwise it is the basename of the source file. In both cases any
-suffix is removed (e.g. @file{foo.00.rtl} or @file{foo.01.sibling}).
+suffix is removed (e.g. @file{foo.01.rtl} or @file{foo.02.sibling}).
Here are the possible letters for use in @var{letters}, and their
meanings:
Annotate the assembler output with miscellaneous debugging information.
@item b
@opindex db
-Dump after computing branch probabilities, to @file{@var{file}.15.bp}.
+Dump after computing branch probabilities, to @file{@var{file}.12.bp}.
@item B
@opindex dB
Dump after block reordering, to @file{@var{file}.31.bbro}.
@item c
@opindex dc
-Dump after instruction combination, to the file @file{@var{file}.21.combine}.
+Dump after instruction combination, to the file @file{@var{file}.20.combine}.
@item C
@opindex dC
-Dump after the first if conversion, to the file @file{@var{file}.16.ce1}.
-Also dump after the second if conversion, to the file @file{@var{file}.22.ce2}.
+Dump after the first if conversion, to the file @file{@var{file}.14.ce1}.
+Also dump after the second if conversion, to the file @file{@var{file}.21.ce2}.
@item d
@opindex dd
-Dump after branch target load optimization, to to @file{@var{file}.33.btl}.
+Dump after branch target load optimization, to to @file{@var{file}.32.btl}.
Also dump after delayed branch scheduling, to @file{@var{file}.36.dbr}.
@item D
@opindex dD
Dump all macro definitions, at the end of preprocessing, in addition to
normal output.
-@item e
-@opindex de
-Dump after SSA optimizations, to @file{@var{file}.04.ssa} and
-@file{@var{file}.07.ussa}.
@item E
@opindex dE
-Dump after the second if conversion, to @file{@var{file}.32.ce3}.
+Dump after the third if conversion, to @file{@var{file}.30.ce3}.
@item f
@opindex df
-Dump after control and data flow analysis, to @file{@var{file}.14.cfg}.
-Also dump after life analysis, to @file{@var{file}.20.life}.
+Dump after control and data flow analysis, to @file{@var{file}.11.cfg}.
+Also dump after life analysis, to @file{@var{file}.19.life}.
@item F
@opindex dF
-Dump after purging @code{ADDRESSOF} codes, to @file{@var{file}.10.addressof}.
+Dump after purging @code{ADDRESSOF} codes, to @file{@var{file}.07.addressof}.
@item g
@opindex dg
-Dump after global register allocation, to @file{@var{file}.26.greg}.
+Dump after global register allocation, to @file{@var{file}.25.greg}.
@item G
@opindex dG
-Dump after GCSE, to @file{@var{file}.11.gcse}.
+Dump after GCSE, to @file{@var{file}.08.gcse}.
Also dump after jump bypassing and control flow optimizations, to
-@file{@var{file}.13.bypass}.
+@file{@var{file}.10.bypass}.
@item h
@opindex dh
-Dump after finalization of EH handling code, to @file{@var{file}.02.eh}.
+Dump after finalization of EH handling code, to @file{@var{file}.03.eh}.
@item i
@opindex di
-Dump after sibling call optimizations, to @file{@var{file}.01.sibling}.
+Dump after sibling call optimizations, to @file{@var{file}.02.sibling}.
@item j
@opindex dj
-Dump after the first jump optimization, to @file{@var{file}.03.jump}.
+Dump after the first jump optimization, to @file{@var{file}.04.jump}.
@item k
@opindex dk
-Dump after conversion from registers to stack, to @file{@var{file}.35.stack}.
+Dump after conversion from registers to stack, to @file{@var{file}.34.stack}.
@item l
@opindex dl
-Dump after local register allocation, to @file{@var{file}.25.lreg}.
+Dump after local register allocation, to @file{@var{file}.24.lreg}.
@item L
@opindex dL
-Dump after loop optimization passes, to @file{@var{file}.12.loop} and
-@file{@var{file}.18.loop2}.
+Dump after loop optimization passes, to @file{@var{file}.09.loop} and
+@file{@var{file}.16.loop2}.
@item M
@opindex dM
Dump after performing the machine dependent reorganization pass, to
-@file{@var{file}.36.mach}.
+@file{@var{file}.35.mach}.
@item n
@opindex dn
-Dump after register renumbering, to @file{@var{file}.30.rnreg}.
+Dump after register renumbering, to @file{@var{file}.29.rnreg}.
@item N
@opindex dN
-Dump after the register move pass, to @file{@var{file}.23.regmove}.
+Dump after the register move pass, to @file{@var{file}.22.regmove}.
@item o
@opindex do
-Dump after post-reload optimizations, to @file{@var{file}.27.postreload}.
+Dump after post-reload optimizations, to @file{@var{file}.26.postreload}.
@item r
@opindex dr
-Dump after RTL generation, to @file{@var{file}.00.rtl}.
+Dump after RTL generation, to @file{@var{file}.01.rtl}.
@item R
@opindex dR
-Dump after the second scheduling pass, to @file{@var{file}.34.sched2}.
+Dump after the second scheduling pass, to @file{@var{file}.33.sched2}.
@item s
@opindex ds
Dump after CSE (including the jump optimization that sometimes follows
-CSE), to @file{@var{file}.09.cse}.
+CSE), to @file{@var{file}.06.cse}.
@item S
@opindex dS
-Dump after the first scheduling pass, to @file{@var{file}.24.sched}.
+Dump after the first scheduling pass, to @file{@var{file}.23.sched}.
@item t
@opindex dt
Dump after the second CSE pass (including the jump optimization that
-sometimes follows CSE), to @file{@var{file}.19.cse2}.
+sometimes follows CSE), to @file{@var{file}.18.cse2}.
@item T
@opindex dT
-Dump after running tracer, to @file{@var{file}.17.tracer}.
+Dump after running tracer, to @file{@var{file}.15.tracer}.
@item u
@opindex du
-Dump after null pointer elimination pass to @file{@var{file}.08.null}.
+Dump after null pointer elimination pass to @file{@var{file}.05.null}.
+@item U
+@opindex dU
+Dump callgraph and unit-at-a-time optimization @file{@var{file}.00.unit}.
+@item V
+@opindex dV
+Dump after the value profile transformations, to @file{@var{file}.13.vpt}.
@item w
@opindex dw
-Dump after the second flow pass, to @file{@var{file}.28.flow2}.
-@item W
-@opindex dW
-Dump after SSA conditional constant propagation, to
-@file{@var{file}.05.ssaccp}.
-@item X
-@opindex dX
-Dump after SSA dead code elimination, to @file{@var{file}.06.ssadce}.
+Dump after the second flow pass, to @file{@var{file}.27.flow2}.
@item z
@opindex dz
-Dump after the peephole pass, to @file{@var{file}.29.peephole2}.
+Dump after the peephole pass, to @file{@var{file}.28.peephole2}.
+@item Z
+@opindex dZ
+Dump after constructing the web, to @file{@var{file}.17.web}.
@item a
@opindex da
Produce all the dumps listed above.
@item v
@opindex dv
For each of the other indicated dump files (except for
-@file{@var{file}.00.rtl}), dump a representation of the control flow graph
+@file{@var{file}.01.rtl}), dump a representation of the control flow graph
suitable for viewing with VCG to @file{@var{file}.@var{pass}.vcg}.
@item x
@opindex dx
@item -frandom-seed=@var{string}
@opindex frandom-string
This option provides a seed that GCC uses when it would otherwise use
-random numbers. At present, this is used to generate certain symbol names
-that have to be different in every compiled file.
+random numbers. It is used to generate certain symbol names
+that have to be different in every compiled file. It is also used to
+place unique stamps in coverage data files and the object files that
+produce them. You can use the @option{-frandom-seed} option to produce
+reproducibly identical object files.
The @var{string} should be different for every file you compile.
This is useful when you use @option{-nostdlib} or @option{-nodefaultlibs}
but you do want to link with @file{libgcc.a}. You can do
-@example
+@smallexample
gcc -nostdlib @var{files}@dots{} `gcc -print-libgcc-file-name`
-@end example
+@end smallexample
@item -print-search-dirs
@opindex print-search-dirs
the performance and/or code size at the expense of compilation time
and possibly the ability to debug the program.
+The compiler performs optimisation based on the knowledge it has of
+the program. Using the @option{-funit-at-a-time} flag will allow the
+compiler to consider information gained from later functions in the
+file when compiling a function. Compiling multiple files at once to a
+single output file (and using @option{-funit-at-a-time}) will allow
+the compiler to use information gained from all of the files when
+compiling each of them.
+
Not all optimizations are controlled directly by a flag. Only
optimizations that have a flag are listed.
time, without performing any optimizations that take a great deal of
compilation time.
-@option{-O} turns on the following optimization flags:
+@option{-O} turns on the following optimization flags:
@gccoptlist{-fdefer-pop @gol
-fmerge-constants @gol
-fthread-jumps @gol
-floop-optimize @gol
--fcrossjumping @gol
-fif-conversion @gol
-fif-conversion2 @gol
-fdelayed-branch @gol
-fstrength-reduce @gol
-fcse-follow-jumps -fcse-skip-blocks @gol
-frerun-cse-after-loop -frerun-loop-opt @gol
--fgcse -fgcse-lm -fgcse-sm @gol
+-fgcse -fgcse-lm -fgcse-sm -fgcse-las @gol
-fdelete-null-pointer-checks @gol
-fexpensive-optimizations @gol
-fregmove @gol
-fpeephole2 @gol
-freorder-blocks -freorder-functions @gol
-fstrict-aliasing @gol
+-funit-at-a-time @gol
-falign-functions -falign-jumps @gol
--falign-loops -falign-labels}
+-falign-loops -falign-labels @gol
+-fcrossjumping}
Please note the warning under @option{-fgcse} about
invoking @option{-O2} on programs that use computed gotos.
@opindex O3
Optimize yet more. @option{-O3} turns on all optimizations specified by
@option{-O2} and also turns on the @option{-finline-functions},
-@option{-funit-at-a-time} and @option{-frename-registers} options.
+@option{-fweb} and @option{-frename-registers} options.
@item -O0
@opindex O0
Inlining is actually controlled by a number of parameters, which may be
specified individually by using @option{--param @var{name}=@var{value}}.
-The @option{-finline-limit=@var{n}} option sets some of these parameters
+The @option{-finline-limit=@var{n}} option sets some of these parameters
as follows:
@table @gcctabopt
- @item max-inline-insns
- is set to @var{n}.
@item max-inline-insns-single
is set to @var{n}/2.
@item max-inline-insns-auto
is set to @var{n}.
@end table
-Using @option{-finline-limit=600} thus results in the default settings
-for these parameters. See below for a documentation of the individual
+See below for a documentation of the individual
parameters controlling inlining.
@emph{Note:} pseudo instruction represents, in this particular context, an
@item -fgcse-sm
@opindex fgcse-sm
-When @option{-fgcse-sm} is enabled, A store motion pass is run after global common
-subexpression elimination. This pass will attempt to move stores out of loops.
-When used in conjunction with @option{-fgcse-lm}, loops containing a load/store sequence
-can be changed to a load before the loop and a store after the loop.
+When @option{-fgcse-sm} is enabled, a store motion pass is run after
+global common subexpression elimination. This pass will attempt to move
+stores out of loops. When used in conjunction with @option{-fgcse-lm},
+loops containing a load/store sequence can be changed to a load before
+the loop and a store after the loop.
+
+Enabled by default when gcse is enabled.
+
+@item -fgcse-las
+@opindex fgcse-las
+When @option{-fgcse-las} is enabled, the global common subexpression
+elimination pass eliminates redundant loads that come after stores to the
+same memory location (both partial and full redundancies).
Enabled by default when gcse is enabled.
sense when scheduling before register allocation, i.e.@: with
@option{-fschedule-insns} or at @option{-O2} or higher.
+@item -fsched-stalled-insns=@var{n}
+@opindex fsched-stalled-insns
+Define how many insns (if any) can be moved prematurely from the queue
+of stalled insns into the ready list, during the second scheduling pass.
+
+@item -fsched-stalled-insns-dep=@var{n}
+@opindex fsched-stalled-insns-dep
+Define how many insn groups (cycles) will be examined for a dependency
+on a stalled insn that is candidate for premature removal from the queue
+of stalled insns. Has an effect only during the second scheduling pass,
+and only if @option{-fsched-stalled-insns} is used and its value is not zero.
+
@item -fsched2-use-superblocks
@opindex fsched2-use-superblocks
-When schedulilng after register allocation, do use superblock scheduling
+When scheduling after register allocation, do use superblock scheduling
algorithm. Superblock scheduling allows motion across basic block boundaries
resulting on faster schedules. This option is experimental, as not all machine
descriptions used by GCC model the CPU closely enough to avoid unreliable
-results from the algorithm.
+results from the algorithm.
This only makes sense when scheduling after register allocation, i.e.@: with
@option{-fschedule-insns2} or at @option{-O2} or higher.
Reorder basic blocks in the compiled function in order to reduce number of
taken branches and improve code locality.
-Enabled at levels @option{-O2}, @option{-O3}, @option{-Os}.
+Enabled at levels @option{-O2}, @option{-O3}.
@item -freorder-functions
@opindex freorder-functions
type.
Pay special attention to code like this:
-@example
+@smallexample
union a_union @{
int i;
double d;
t.d = 3.0;
return t.i;
@}
-@end example
+@end smallexample
The practice of reading from a different union member than the one most
recently written to (called ``type-punning'') is common. Even with
@option{-fstrict-aliasing}, type-punning is allowed, provided the memory
is accessed through the union type. So, the code above will work as
expected. However, this code might not:
-@example
+@smallexample
int f() @{
a_union t;
int* ip;
ip = &t.i;
return *ip;
@}
-@end example
+@end smallexample
Every language that wishes to perform language-specific alias analysis
should define a function that computes, given an @code{tree}
Some assemblers only support this flag when @var{n} is a power of two;
in that case, it is rounded up.
-If @var{n} is not specified, use a machine-dependent default.
+If @var{n} is not specified or is zero, use a machine-dependent default.
Enabled at levels @option{-O2}, @option{-O3}.
make code slower, because it must insert dummy operations for when the
branch target is reached in the usual flow of the code.
+@option{-fno-align-labels} and @option{-falign-labels=1} are
+equivalent and mean that labels will not be aligned.
+
If @option{-falign-loops} or @option{-falign-jumps} are applicable and
are greater than this value, then their values are used instead.
-If @var{n} is not specified, use a machine-dependent default which is
-very likely to be @samp{1}, meaning no alignment.
+If @var{n} is not specified or is zero, use a machine-dependent default
+which is very likely to be @samp{1}, meaning no alignment.
Enabled at levels @option{-O2}, @option{-O3}.
executed many times, which will make up for any execution of the dummy
operations.
-If @var{n} is not specified, use a machine-dependent default.
+@option{-fno-align-loops} and @option{-falign-loops=1} are
+equivalent and mean that loops will not be aligned.
+
+If @var{n} is not specified or is zero, use a machine-dependent default.
Enabled at levels @option{-O2}, @option{-O3}.
bytes like @option{-falign-functions}. In this case, no dummy operations
need be executed.
-If @var{n} is not specified, use a machine-dependent default.
+@option{-fno-align-jumps} and @option{-falign-jumps=1} are
+equivalent and mean that loops will not be aligned.
+
+If @var{n} is not specified or is zero, use a machine-dependent default.
Enabled at levels @option{-O2}, @option{-O3}.
make debugging impossible, since variables will no longer stay in
a ``home register''.
+@item -fweb
+@opindex fweb
+Constructs webs as commonly used for register allocation purposes and assign
+each web individual pseudo register. This allows our register allocation pass
+to operate on pseudos directly, but also strengthens several other optimization
+passes, such as CSE, loop optimizer and trivial dead code remover. It can,
+however, make debugging impossible, since variables will no longer stay in a
+``home register''.
+
Enabled at levels @option{-O3}.
@item -fno-cprop-registers
Disabled at levels @option{-O}, @option{-O2}, @option{-O3}, @option{-Os}.
+@item -fprofile-generate
+@opindex fprofile-generate
+Enable options usually used for instrumenting application to produce profile usefull
+for later recompilation profile feedback based optimization.
+
+The following options are enabled: @code{-fprofile-arcs}, @code{-fprofile-values}, @code{-fvpt}
+
+@item -fprofile-use
+@opindex fprofile-use
+Enable profile feedback directed optimizations, and optimizations
+generally profitable only with profile feedback available.
+
+The following options are enabled: @code{-fbranch-probabilities},
+@code{-fvpt}, @code{-funroll-loops}, @code{-fpeel-loops}, @code{-ftracer}.
+
@end table
The following options control compiler behavior regarding floating
@item -ffast-math
@opindex ffast-math
Sets @option{-fno-math-errno}, @option{-funsafe-math-optimizations}, @*
-@option{-fno-trapping-math}, @option{-ffinite-math-only} and @*
-@option{-fno-signaling-nans}.
+@option{-fno-trapping-math}, @option{-ffinite-math-only},
+@option{-fno-rounding-math} and @option{-fno-signaling-nans}.
This option causes the preprocessor macro @code{__FAST_MATH__} to be defined.
The default is @option{-ftrapping-math}.
+@item -frounding-math
+@opindex frounding-math
+Disable transformations and optimizations that assume default floating
+point rounding behavior. This is round-to-zero for all floating point
+to integer conversions, and round-to-nearest for all other arithmetic
+truncations. This option should be specified for programs that change
+the FP rounding mode dynamically, or that may be executed with a
+non-default rounding mode. This option disables constant folding of
+floating point expressions at compile-time (which may be affected by
+rounding mode) and arithmetic transformations that are unsafe in the
+presence of sign-dependent rounding modes.
+
+The default is @option{-fno-rounding-math}.
+
+This option is experimental and does not currently guarantee to
+disable all GCC optimizations that are affected by rounding mode.
+Future versions of gcc may provide finer control of this setting
+using C99's @code{FENV_ACCESS} pragma. This command line option
+will be used to specify the default state for @code{FENV_ACCESS}.
+
@item -fsignaling-nans
@opindex fsignaling-nans
Compile code assuming that IEEE signaling NaNs may generate user-visible
@option{-fbranch-probabilities}, to improve optimizations based on
the number of times each branch was taken. When the program
compiled with @option{-fprofile-arcs} exits it saves arc execution
-counts to a file called @file{@var{sourcename}.da} for each source
+counts to a file called @file{@var{sourcename}.gcda} for each source
file The information in this data file is very dependent on the
structure of the generated code, so you must use the same source code
and the same optimization options for both compilations.
-With @option{-fbranch-probabilities}, GCC puts a
+With @option{-fbranch-probabilities}, GCC puts a
@samp{REG_BR_PROB} note on each @samp{JUMP_INSN} and @samp{CALL_INSN}.
These can be used to improve optimization. Currently, they are only
used in one place: in @file{reorg.c}, instead of guessing which path a
branch is mostly to take, the @samp{REG_BR_PROB} values are used to
exactly determine which path is taken more often.
+@item -fprofile-values
+@opindex fprofile-values
+If combined with @option{-fprofile-arcs}, it adds code so that some
+data about values of expressions in the program is gathered.
+
+With @option{-fbranch-probabilities}, it reads back the data gathered
+from profiling values of expressions and adds @samp{REG_VALUE_PROFILE}
+notes to instructions for their later usage in optimizations.
+
+@item -fvpt
+@opindex fvpt
+If combined with @option{-fprofile-arcs}, it instructs the compiler to add
+a code to gather information about values of expressions.
+
+With @option{-fbranch-probabilities}, it reads back the data gathered
+and actually performs the optimizations based on them.
+Currently the optimizations include specialization of division operation
+using the knowledge about the value of the denominator.
+
@item -fnew-ra
@opindex fnew-ra
Use a graph coloring register allocator. Currently this option is meant
@item -funit-at-a-time
@opindex funit-at-a-time
-Parse the whole compilation unit before starting to produce code. This allows some
-extra optimizations to take place but consumes more memory.
+Parse the whole compilation unit before starting to produce code.
+This allows some extra optimizations to take place but consumes more
+memory.
@item -funroll-loops
@opindex funroll-loops
recognition is based on notes from frontend. This usually makes programs run more slowly.
@option{-fold-unroll-all-loops} implies the same options as
@option{-fold-unroll-loops}.
-
+
@item -funswitch-loops
@opindex funswitch-loops
Move branches with loop invariant conditions out of the loop, with duplicates
specify this option and you may have problems with debugging if
you specify both this option and @option{-g}.
-@item -fssa
-@opindex fssa
-Perform optimizations in static single assignment form. Each function's
-flow graph is translated into SSA form, optimizations are performed, and
-the flow graph is translated back from SSA form. Users should not
-specify this option, since it is not yet ready for production use.
-
-@item -fssa-ccp
-@opindex fssa-ccp
-Perform Sparse Conditional Constant Propagation in SSA form. Requires
-@option{-fssa}. Like @option{-fssa}, this is an experimental feature.
-
-@item -fssa-dce
-@opindex fssa-dce
-Perform aggressive dead-code elimination in SSA form. Requires @option{-fssa}.
-Like @option{-fssa}, this is an experimental feature.
-
@item -fbranch-target-load-optimize
@opindex fbranch-target-load-optimize
Perform branch target register load optimization before prologue / epilogue
Perform branch target register load optimization after prologue / epilogue
threading.
-
-
+@item -fbtr-bb-exclusive
+@opindex fbtr-bb-exclusive
+WHen performing branch target register load optimization, don't reuse
+branch target registers in within any basic block.
@item --param @var{name}=@var{value}
@opindex param
control some of these constants on the command-line using the
@option{--param} option.
+The names of specific parameters, and the meaning of the values, are
+tied to the internals of the compiler, and are subject to change
+without notice in future releases.
+
In each case, the @var{value} is an integer. The allowable choices for
@var{name} are given in the following table:
@item max-inline-insns-single
Several parameters control the tree inliner used in gcc.
This number sets the maximum number of instructions (counted in gcc's
-internal representation) in a single function that the tree inliner
+internal representation) in a single function that the tree inliner
will consider for inlining. This only affects functions declared
inline and methods implemented in a class declaration (C++).
-The default value is 300.
+The default value is 500.
@item max-inline-insns-auto
When you use @option{-finline-functions} (included in @option{-O3}),
by the compiler will be investigated. To those functions, a different
(more restrictive) limit compared to functions declared inline can
be applied.
-The default value is 300.
-
-@item max-inline-insns
-The tree inliner does decrease the allowable size for single functions
-to be inlined after we already inlined the number of instructions
-given here by repeated inlining. This number should be a factor of
-two or more larger than the single function limit.
-Higher numbers result in better runtime performance, but incur higher
-compile-time resource (CPU time, memory) requirements and result in
-larger binaries. Very high values are not advisable, as too large
-binaries may adversely affect runtime performance.
-The default value is 600.
-
-@item max-inline-slope
-After exceeding the maximum number of inlined instructions by repeated
-inlining, a linear function is used to decrease the allowable size
-for single functions. The slope of that function is the negative
-reciprocal of the number specified here.
-The default value is 32.
-
-@item min-inline-insns
-The repeated inlining is throttled more and more by the linear function
-after exceeding the limit. To avoid too much throttling, a minimum for
-this function is specified here to allow repeated inlining for very small
-functions even when a lot of repeated inlining already has been done.
-The default value is 130.
+The default value is 120.
+
+@item large-function-insns
+The limit specifying really large functions. For functions greater than this
+limit inlining is constrained by @option{--param large-function-growth}.
+This parameter is useful primarily to avoid extreme compilation time caused by non-linear
+algorithms used by the backend.
+This parameter is ignored when @option{-funit-at-a-time} is not used.
+The default value is 3000.
+
+@item large-function-growth
+Specifies maximal growth of large functtion caused by inlining in percents.
+This parameter is ignored when @option{-funit-at-a-time} is not used.
+The default value is 200.
+
+@item inline-unit-growth
+Specifies maximal overall growth of the compilation unit caused by inlining.
+This parameter is ignored when @option{-funit-at-a-time} is not used.
+The default value is 150.
@item max-inline-insns-rtl
For languages that use the RTL inliner (this happens at a later stage
-than tree inlining), you can set the maximum allowable size (counted
+than tree inlining), you can set the maximum allowable size (counted
in RTL instructions) for the RTL inliner with this parameter.
The default value is 600.
-
@item max-unrolled-insns
The maximum number of instructions that a loop should have if that loop
is unrolled, and if the loop is unrolled, it determines how many times
this parameter and @option{ggc-min-expand} to zero causes a full
collection to occur at every opportunity.
+@item max-reload-search-insns
+The maximum number of instruction reload should look backward for equivalent
+register. Increasing values mean more aggressive optimization, making the
+compile time increase with probably slightly better performance. The default
+value is 100.
+
+@item max-cselib-memory-location
+The maximum number of memory locations cselib should take into acount.
+Increasing values mean more aggressive optimization, making the compile time
+increase with probably slightly better performance. The default value is 500.
+
@item reorder-blocks-duplicate
@itemx reorder-blocks-duplicate-feedback
Used by basic block reordering pass to decide whether to use unconditional
-branch or duplicate the code on it's destination. Code is duplicated when it's
+branch or duplicate the code on its destination. Code is duplicated when its
estimated size is smaller than this value multiplied by the estimated size of
unconditional jump in the hot spots of the program.
For each subprogram to be run, the compiler driver first tries the
@option{-B} prefix, if any. If that name is not found, or if @option{-B}
was not specified, the driver tries two standard prefixes, which are
-@file{/usr/lib/gcc/} and @file{/usr/local/lib/gcc-lib/}. If neither of
+@file{/usr/lib/gcc/} and @file{/usr/local/lib/gcc/}. If neither of
those results in a file name that is found, the unmodified program
name is searched for using the directories specified in your
@env{PATH} environment variable.
This way, @code{if-exists-else} can be used to select one file or another,
based on the existence of the first. Here is a small example of its usage:
-@smallexample
+@smallexample
*startfile:
crt0%O%s %:if-exists(crti%O%s) \
%:if-exists-else(crtbeginT%O%s crtbegin%O%s)
@end smallexample
-@end table
+@end table
@item %@{@code{S}@}
Substitutes the @code{-S} switch, if that switch was given to GCC@.
@item %@{S:X; T:Y; :D@}
-If @code{S} was given to GCC, substitues @code{X}; else if @code{T} was
-given to GCC, substitues @code{Y}; else substitutes @code{D}. There can
-be as many clauses as you need. This may be combined with @code{.},
+If @code{S} was given to GCC, substitutes @code{X}; else if @code{T} was
+given to GCC, substitutes @code{Y}; else substitutes @code{D}. There can
+be as many clauses as you need. This may be combined with @code{.},
@code{!}, @code{|}, and @code{*} as needed.
* VAX Options::
* SPARC Options::
* ARM Options::
-* MN10200 Options::
* MN10300 Options::
* M32R/D Options::
-* M88K Options::
* RS/6000 and PowerPC Options::
* Darwin Options::
-* RT Options::
* MIPS Options::
* i386 and x86-64 Options::
* HPPA Options::
Do not (do) assume that unaligned memory references will be handled by
the system.
+@item -msep-data
+Generate code that allows the data segment to be located in a different
+area of memory from the text segment. This allows for execute in place in
+an environment without virtual memory management. This option implies -fPIC.
+
+@item -mno-sep-data
+Generate code that assumes that the data segment follows the text segment.
+This is the default.
+
+@item -mid-shared-library
+Generate code that supports shared libraries via the library ID method.
+This allows for execute in place and shared libraries in an environment
+without virtual memory management. This option implies -fPIC.
+
+@item -mno-id-shared-library
+Generate code that doesn't assume ID based shared libraries are being used.
+This is the default.
+
+@item -mshared-library-id=n
+Specified the identification number of the ID based shared library being
+compiled. Specifying a value of 0 will generate more compact code, specifying
+other values will force the allocation of that number to the current
+library but is no more space or time efficient than omitting this option.
+
@end table
@node M68hc1x Options
@itemx -m68hcs12
@opindex m68S12
@opindex m68hcs12
-Generate output for a 68HCS12.
+Generate output for a 68HCS12.
@item -mauto-incdec
@opindex mauto-incdec
Generate output containing quad-word (long double) floating point
instructions.
-@item -mimpure-text
-@opindex mimpure-text
-@option{-mimpure-text}, used in addition to @option{-shared}, tells
-the compiler to not pass @option{-z text} to the linker when linking a
-shared object. Using this option, you can link position-dependent
-code into a shared object.
-
-@option{-mimpure-text} suppresses the ``relocations remain against
-allocatable but non-writable sections'' linker error message.
-However, the necessary relocations will trigger copy-on-write, and the
-shared object is not actually shared across processes. Instead of
-using @option{-mimpure-text}, you should compile all source code with
-@option{-fpic} or @option{-fPIC}.
-
-This option is only available on SunOS and Solaris.
-
@item -msoft-quad-float
@opindex msoft-quad-float
Generate output containing library calls for quad-word (long double)
acknowledges that their resulting code will not be directly in line with
the rules of the ABI@.
+@item -mimpure-text
+@opindex mimpure-text
+@option{-mimpure-text}, used in addition to @option{-shared}, tells
+the compiler to not pass @option{-z text} to the linker when linking a
+shared object. Using this option, you can link position-dependent
+code into a shared object.
+
+@option{-mimpure-text} suppresses the ``relocations remain against
+allocatable but non-writable sections'' linker error message.
+However, the necessary relocations will trigger copy-on-write, and the
+shared object is not actually shared across processes. Instead of
+using @option{-mimpure-text}, you should compile all source code with
+@option{-fpic} or @option{-fPIC}.
+
+This option is only available on SunOS and Solaris.
+
@item -mv8
@itemx -msparclite
@opindex mv8
@table @gcctabopt
@item -mlittle-endian
@opindex mlittle-endian
-Generate code for a processor running in little-endian mode.
+Generate code for a processor running in little-endian mode. It is only
+available for a few configurations and most notably not on Solaris.
@item -m32
@itemx -m64
@samp{arm7500}, @samp{arm7500fe}, @samp{arm7tdmi}, @samp{arm8},
@samp{strongarm}, @samp{strongarm110}, @samp{strongarm1100},
@samp{arm8}, @samp{arm810}, @samp{arm9}, @samp{arm9e}, @samp{arm920},
-@samp{arm920t}, @samp{arm940t}, @samp{arm9tdmi}, @samp{arm10tdmi},
-@samp{arm1020t}, @samp{xscale}, @samp{iwmmxt}, @samp{ep9312}.
+@samp{arm920t}, @samp{arm926ejs}, @samp{arm940t}, @samp{arm9tdmi},
+@samp{arm10tdmi}, @samp{arm1020t}, @samp{arm1026ejs},
+@samp{arm1136js}, @samp{arm1136jfs} ,@samp{xscale}, @samp{iwmmxt},
+@samp{ep9312}.
@itemx -mtune=@var{name}
@opindex mtune
assembly code. This option can be used in conjunction with or instead
of the @option{-mcpu=} option. Permissible names are: @samp{armv2},
@samp{armv2a}, @samp{armv3}, @samp{armv3m}, @samp{armv4}, @samp{armv4t},
-@samp{armv5}, @samp{armv5t}, @samp{armv5te}, @samp{iwmmxt}, @samp{ep9312}.
+@samp{armv5}, @samp{armv5t}, @samp{armv5te}, @samp{armv6j},
+@samp{iwmmxt}, @samp{ep9312}.
@item -mfpe=@var{number}
@itemx -mfp=@var{number}
@end table
-@node MN10200 Options
-@subsection MN10200 Options
-@cindex MN10200 options
-
-These @option{-m} options are defined for Matsushita MN10200 architectures:
-@table @gcctabopt
-
-@item -mrelax
-@opindex mrelax
-Indicate to the linker that it should perform a relaxation optimization pass
-to shorten branches, calls and absolute memory addresses. This option only
-has an effect when used on the command line for the final link step.
-
-This option makes symbolic debugging impossible.
-@end table
-
@node MN10300 Options
@subsection MN10300 Options
@cindex MN10300 options
@subsection M32R/D Options
@cindex M32R/D options
-These @option{-m} options are defined for Mitsubishi M32R/D architectures:
+These @option{-m} options are defined for Renesas M32R/D architectures:
@table @gcctabopt
+@item -m32r2
+@opindex m32r2
+Generate code for the M32R/2@.
+
@item -m32rx
@opindex m32rx
Generate code for the M32R/X@.
@opindex m32r
Generate code for the M32R@. This is the default.
-@item -mcode-model=small
-@opindex mcode-model=small
+@item -mmodel=small
+@opindex mmodel=small
Assume all objects live in the lower 16MB of memory (so that their addresses
can be loaded with the @code{ld24} instruction), and assume all subroutines
are reachable with the @code{bl} instruction.
The addressability of a particular object can be set with the
@code{model} attribute.
-@item -mcode-model=medium
-@opindex mcode-model=medium
+@item -mmodel=medium
+@opindex mmodel=medium
Assume objects may be anywhere in the 32-bit address space (the compiler
will generate @code{seth/add3} instructions to load their addresses), and
assume all subroutines are reachable with the @code{bl} instruction.
-@item -mcode-model=large
-@opindex mcode-model=large
+@item -mmodel=large
+@opindex mmodel=large
Assume objects may be anywhere in the 32-bit address space (the compiler
will generate @code{seth/add3} instructions to load their addresses), and
assume subroutines may not be reachable with the @code{bl} instruction
doesn't the linker will give an error message---incorrect code will not be
generated.
-@end table
-
-@node M88K Options
-@subsection M88K Options
-@cindex M88k options
-
-These @samp{-m} options are defined for Motorola 88k architectures:
-
-@table @gcctabopt
-@item -m88000
-@opindex m88000
-Generate code that works well on both the m88100 and the
-m88110.
-
-@item -m88100
-@opindex m88100
-Generate code that works best for the m88100, but that also
-runs on the m88110.
-
-@item -m88110
-@opindex m88110
-Generate code that works best for the m88110, and may not run
-on the m88100.
-
-@item -mbig-pic
-@opindex mbig-pic
-Obsolete option to be removed from the next revision.
-Use @option{-fPIC}.
-
-@item -midentify-revision
-@opindex midentify-revision
-@cindex identifying source, compiler (88k)
-Include an @code{ident} directive in the assembler output recording the
-source file name, compiler name and version, timestamp, and compilation
-flags used.
-
-@item -mno-underscores
-@opindex mno-underscores
-@cindex underscores, avoiding (88k)
-In assembler output, emit symbol names without adding an underscore
-character at the beginning of each name. The default is to use an
-underscore as prefix on each name.
-
-@item -mocs-debug-info
-@itemx -mno-ocs-debug-info
-@opindex mocs-debug-info
-@opindex mno-ocs-debug-info
-@cindex OCS (88k)
-@cindex debugging, 88k OCS
-Include (or omit) additional debugging information (about registers used
-in each stack frame) as specified in the 88open Object Compatibility
-Standard, ``OCS''@. This extra information allows debugging of code that
-has had the frame pointer eliminated. The default for SVr4 and Delta 88
-SVr3.2 is to include this information; other 88k configurations omit this
-information by default.
-
-@item -mocs-frame-position
-@opindex mocs-frame-position
-@cindex register positions in frame (88k)
-When emitting COFF debugging information for automatic variables and
-parameters stored on the stack, use the offset from the canonical frame
-address, which is the stack pointer (register 31) on entry to the
-function. The SVr4 and Delta88 SVr3.2, and BCS configurations use
-@option{-mocs-frame-position}; other 88k configurations have the default
-@option{-mno-ocs-frame-position}.
-
-@item -mno-ocs-frame-position
-@opindex mno-ocs-frame-position
-@cindex register positions in frame (88k)
-When emitting COFF debugging information for automatic variables and
-parameters stored on the stack, use the offset from the frame pointer
-register (register 30). When this option is in effect, the frame
-pointer is not eliminated when debugging information is selected by the
--g switch.
-
-@item -moptimize-arg-area
-@opindex moptimize-arg-area
-@cindex arguments in frame (88k)
-Save space by reorganizing the stack frame. This option generates code
-that does not agree with the 88open specifications, but uses less
-memory.
-
-@itemx -mno-optimize-arg-area
-@opindex mno-optimize-arg-area
-Do not reorganize the stack frame to save space. This is the default.
-The generated conforms to the specification, but uses more memory.
-
-@item -mshort-data-@var{num}
-@opindex mshort-data
-@cindex smaller data references (88k)
-@cindex r0-relative references (88k)
-Generate smaller data references by making them relative to @code{r0},
-which allows loading a value using a single instruction (rather than the
-usual two). You control which data references are affected by
-specifying @var{num} with this option. For example, if you specify
-@option{-mshort-data-512}, then the data references affected are those
-involving displacements of less than 512 bytes.
-@option{-mshort-data-@var{num}} is not effective for @var{num} greater
-than 64k.
-
-@item -mserialize-volatile
-@opindex mserialize-volatile
-@itemx -mno-serialize-volatile
-@opindex mno-serialize-volatile
-@cindex sequential consistency on 88k
-Do, or don't, generate code to guarantee sequential consistency
-of volatile memory references. By default, consistency is
-guaranteed.
-
-The order of memory references made by the MC88110 processor does
-not always match the order of the instructions requesting those
-references. In particular, a load instruction may execute before
-a preceding store instruction. Such reordering violates
-sequential consistency of volatile memory references, when there
-are multiple processors. When consistency must be guaranteed,
-GCC generates special instructions, as needed, to force
-execution in the proper order.
-
-The MC88100 processor does not reorder memory references and so
-always provides sequential consistency. However, by default, GCC
-generates the special instructions to guarantee consistency
-even when you use @option{-m88100}, so that the code may be run on an
-MC88110 processor. If you intend to run your code only on the
-MC88100 processor, you may use @option{-mno-serialize-volatile}.
-
-The extra code generated to guarantee consistency may affect the
-performance of your application. If you know that you can safely
-forgo this guarantee, you may use @option{-mno-serialize-volatile}.
-
-@item -msvr4
-@itemx -msvr3
-@opindex msvr4
-@opindex msvr3
-@cindex assembler syntax, 88k
-@cindex SVr4
-Turn on (@option{-msvr4}) or off (@option{-msvr3}) compiler extensions
-related to System V release 4 (SVr4). This controls the following:
-
-@enumerate
-@item
-Which variant of the assembler syntax to emit.
-@item
-@option{-msvr4} makes the C preprocessor recognize @samp{#pragma weak}
-that is used on System V release 4.
-@item
-@option{-msvr4} makes GCC issue additional declaration directives used in
-SVr4.
-@end enumerate
-
-@option{-msvr4} is the default for the m88k-motorola-sysv4 configuration.
-@option{-msvr3} is the default for all other m88k configurations.
-
-@item -mversion-03.00
-@opindex mversion-03.00
-This option is obsolete, and is ignored.
-@c ??? which asm syntax better for GAS? option there too?
-
-@item -mno-check-zero-division
-@itemx -mcheck-zero-division
-@opindex mno-check-zero-division
-@opindex mcheck-zero-division
-@cindex zero division on 88k
-Do, or don't, generate code to guarantee that integer division by
-zero will be detected. By default, detection is guaranteed.
-
-Some models of the MC88100 processor fail to trap upon integer
-division by zero under certain conditions. By default, when
-compiling code that might be run on such a processor, GCC
-generates code that explicitly checks for zero-valued divisors
-and traps with exception number 503 when one is detected. Use of
-@option{-mno-check-zero-division} suppresses such checking for code
-generated to run on an MC88100 processor.
-
-GCC assumes that the MC88110 processor correctly detects all instances
-of integer division by zero. When @option{-m88110} is specified, no
-explicit checks for zero-valued divisors are generated, and both
-@option{-mcheck-zero-division} and @option{-mno-check-zero-division} are
-ignored.
+@item -mdebug
+@opindex -mdebug
+Makes the M32R specific code in the compiler display some statistics
+that might help in debugging programs.
+
+@item -malign-loops
+@opindex malign-loops
+Align all loops to a 32-byte boundary.
+
+@item -mno-align-loops
+@opindex mno-align-loops
+Do not enforce a 32-byte alignment for loops. This is the default.
+
+@item -missue-rate=@var{number}
+@opindex missue-rate=@var{number}
+Issue @var{number} instructions per cycle. @var{number} can only be 1
+or 2.
+
+@item -mbranch-cost=@var{number}
+@opindex mbranch-cost=@var{number}
+@var{number} can only be 1 or 2. If it is 1 then branches will be
+preferred over conditional code, if it is 2, then the opposite will
+apply.
+
+@item -mflush-trap=@var{number}
+@opindex mflush-trap=@var{number}
+Specifies the trap number to use to flush the cache. The default is
+12. Valid numbers are between 0 and 15 inclusive.
+
+@item -mno-flush-trap
+@opindex mno-flush-trap
+Specifies that the cache cannot be flushed by using a trap.
+
+@item -mflush-func=@var{name}
+@opindex mflush-func=@var{name}
+Specifies the name of the operating system function to call to flush
+the cache. The default is @emph{_flush_cache}, but a function call
+will only be used if a trap is not available.
+
+@item -mno-flush-func
+@opindex mno-flush-func
+Indicates that there is no OS function for flushing the cache.
-@item -muse-div-instruction
-@opindex muse-div-instruction
-@cindex divide instruction, 88k
-Use the div instruction for signed integer division on the
-MC88100 processor. By default, the div instruction is not used.
-
-On the MC88100 processor the signed integer division instruction
-div) traps to the operating system on a negative operand. The
-operating system transparently completes the operation, but at a
-large cost in execution time. By default, when compiling code
-that might be run on an MC88100 processor, GCC emulates signed
-integer division using the unsigned integer division instruction
-divu), thereby avoiding the large penalty of a trap to the
-operating system. Such emulation has its own, smaller, execution
-cost in both time and space. To the extent that your code's
-important signed integer division operations are performed on two
-nonnegative operands, it may be desirable to use the div
-instruction directly.
-
-On the MC88110 processor the div instruction (also known as the
-divs instruction) processes negative operands without trapping to
-the operating system. When @option{-m88110} is specified,
-@option{-muse-div-instruction} is ignored, and the div instruction is used
-for signed integer division.
-
-Note that the result of dividing @code{INT_MIN} by @minus{}1 is undefined. In
-particular, the behavior of such a division with and without
-@option{-muse-div-instruction} may differ.
-
-@item -mtrap-large-shift
-@itemx -mhandle-large-shift
-@opindex mtrap-large-shift
-@opindex mhandle-large-shift
-@cindex bit shift overflow (88k)
-@cindex large bit shifts (88k)
-Include code to detect bit-shifts of more than 31 bits; respectively,
-trap such shifts or emit code to handle them properly. By default GCC
-makes no special provision for large bit shifts.
-
-@item -mwarn-passed-structs
-@opindex mwarn-passed-structs
-@cindex structure passing (88k)
-Warn when a function passes a struct as an argument or result.
-Structure-passing conventions have changed during the evolution of the C
-language, and are often the source of portability problems. By default,
-GCC issues no such warning.
@end table
-@c break page here to avoid unsightly interparagraph stretch.
-@c -zw, 2001-8-17
-@page
-
@node RS/6000 and PowerPC Options
@subsection IBM RS/6000 and PowerPC Options
@cindex RS/6000 and PowerPC Options
@opindex mcpu
Set architecture type, register usage, choice of mnemonics, and
instruction scheduling parameters for machine type @var{cpu_type}.
-Supported values for @var{cpu_type} are @samp{rios}, @samp{rios1},
-@samp{rsc}, @samp{rios2}, @samp{rs64a}, @samp{601}, @samp{602},
-@samp{603}, @samp{603e}, @samp{604}, @samp{604e}, @samp{620},
-@samp{630}, @samp{740}, @samp{7400}, @samp{7450}, @samp{750},
-@samp{power}, @samp{power2}, @samp{powerpc}, @samp{403}, @samp{505},
-@samp{801}, @samp{821}, @samp{823}, and @samp{860} and @samp{common}.
+Supported values for @var{cpu_type} are @samp{401}, @samp{403},
+@samp{405}, @samp{405fp}, @samp{440}, @samp{440fp}, @samp{505},
+@samp{601}, @samp{602}, @samp{603}, @samp{603e}, @samp{604},
+@samp{604e}, @samp{620}, @samp{630}, @samp{740}, @samp{7400},
+@samp{7450}, @samp{750}, @samp{801}, @samp{821}, @samp{823},
+@samp{860}, @samp{970}, @samp{common}, @samp{ec603e}, @samp{G3},
+@samp{G4}, @samp{G5}, @samp{power}, @samp{power2}, @samp{power3},
+@samp{power4}, @samp{powerpc}, @samp{powerpc64}, @samp{rios},
+@samp{rios1}, @samp{rios2}, @samp{rsc}, and @samp{rs64a}.
@option{-mcpu=common} selects a completely generic processor. Code
generated under this option will run on any POWER or PowerPC processor.
those options will run best on that processor, and may not run at all on
others.
-The @option{-mcpu} options automatically enable or disable other
-@option{-m} options as follows:
-
-@table @samp
-@item common
-@option{-mno-power}, @option{-mno-powerpc}
-
-@item power
-@itemx power2
-@itemx rios1
-@itemx rios2
-@itemx rsc
-@option{-mpower}, @option{-mno-powerpc}, @option{-mno-new-mnemonics}
-
-@item powerpc
-@itemx rs64a
-@itemx 602
-@itemx 603
-@itemx 603e
-@itemx 604
-@itemx 620
-@itemx 630
-@itemx 740
-@itemx 7400
-@itemx 7450
-@itemx 750
-@itemx 505
-@option{-mno-power}, @option{-mpowerpc}, @option{-mnew-mnemonics}
-
-@item 601
-@option{-mpower}, @option{-mpowerpc}, @option{-mnew-mnemonics}
-
-@item 403
-@itemx 821
-@itemx 860
-@option{-mno-power}, @option{-mpowerpc}, @option{-mnew-mnemonics}, @option{-msoft-float}
-@end table
+The @option{-mcpu} options automatically enable or disable the
+following options: @option{-maltivec}, @option{-mhard-float},
+@option{-mmfcrf}, @option{-mmultiple}, @option{-mnew-mnemonics},
+@option{-mpower}, @option{-mpower2}, @option{-mpowerpc64},
+@option{-mpowerpc-gpopt}, @option{-mpowerpc-gfxopt},
+@option{-mstring}. The particular options set for any particular CPU
+will vary between compiler versions, depending on what setting seems
+to produce optimal code for that CPU; it doesn't necessarily reflect
+the actual hardware's capabilities. If you wish to set an individual
+option to a particular value, you may specify it after the
+@option{-mcpu} option, like @samp{-mcpu=970 -mno-altivec}.
+
+On AIX, the @option{-maltivec} and @option{-mpowerpc64} options are
+not enabled or disabled by the @option{-mcpu} option at present, since
+AIX does not have full support for these options. You may still
+enable or disable them individually if you're sure it'll work in your
+environment.
@item -mtune=@var{cpu_type}
@opindex mtune
@itemx -malign-power
@opindex malign-natural
@opindex malign-power
-On AIX, Darwin, and 64-bit PowerPC Linux, the option
+On AIX, Darwin, and 64-bit PowerPC GNU/Linux, the option
@option{-malign-natural} overrides the ABI-defined alignment of larger
types, such as floating-point doubles, on their natural size-based boundary.
The option @option{-malign-power} instructs GCC to follow the ABI-specified
resulting code is suitable for applications, but not shared
libraries.
+@item -mprioritize-restricted-insns=@var{priority}
+@opindex mprioritize-restricted-insns
+This option controls the priority that is assigned to
+dispatch-slot restricted instructions during the second scheduling
+pass. The argument @var{priority} takes the value @var{0/1/2} to assign
+@var{no/highest/second-highest} priority to dispatch slot restricted
+instructions.
+
+@item -msched-costly-dep=@var{dependence_type}
+@opindex msched-costly-dep
+This option controls which dependences are considered costly
+by the target during instruction scheduling. The argument
+@var{dependence_type} takes one of the following values:
+@var{no}: no dependence is costly,
+@var{all}: all dependences are costly,
+@var{true_store_to_load}: a true dependence from store to load is costly,
+@var{store_to_load}: any dependence from store to load is costly,
+@var{number}: any dependence which latency >= @var{number} is costly.
+
+@item -minsert-sched-nops=@var{scheme}
+@opindex minsert-sched-nops
+This option controls which nop insertion scheme will be used during
+the second scheduling pass. The argument @var{scheme} takes one of the
+following values:
+@var{no}: Don't insert nops.
+@var{pad}: Pad with nops any dispatch group which has vacant issue slots,
+according to the scheduler's grouping.
+@var{regroup_exact}: Insert nops to force costly dependent insns into
+separate groups. Insert exactly as many nops as needed to force an insn
+to a new group, according to the estimated processor grouping.
+@var{number}: Insert nops to force costly dependent insns into
+separate groups. Insert @var{number} nops to force an insn to a new group.
+
@item -mcall-sysv
@opindex mcall-sysv
On System V.4 and embedded PowerPC systems compile code using calling
as can the GNU linker for PowerPC/64. It is planned to add this feature
to the GNU linker for 32-bit PowerPC systems as well.
+On Mach-O (Darwin) systems, this option directs the compiler emit to
+the glue for every direct call, and the Darwin linker decides whether
+to use or discard it.
+
In the future, we may cause GCC to ignore all longcall specifications
when the linker is known to generate glue.
system. They are useful for compatibility with other Mac OS compilers.
@table @gcctabopt
-@item -all_load
-@opindex all_load
+@item -all_load
+@opindex all_load
Loads all members of static archive libraries.
See man ld(1) for more information.
Causes the output file to be marked such that the dynamic linker will
bind all undefined references when the file is loaded or launched.
-@item -bundle
+@item -bundle
@opindex bundle
Produce a Mach-o bundle format file.
See man ld(1) for more information.
output file being linked. See man ld(1) for more information.
@item -allowable_client @var{client_name}
-@item -arch_only
-
-@item -client_name
-@item -compatibility_version
-@item -current_version
-@item -dependency-file
-@item -dylib_file
-@item -dylinker_install_name
-@item -dynamic
-@item -dynamiclib
-@item -exported_symbols_list
-@item -filelist
-@item -flat_namespace
-@item -force_cpusubtype_ALL
-@item -force_flat_namespace
-@item -headerpad_max_install_names
-@item -image_base
-@item -init
-@item -install_name
-@item -keep_private_externs
-@item -multi_module
-@item -multiply_defined
-@item -multiply_defined_unused
-@item -noall_load
-@item -nomultidefs
-@item -noprebind
-@item -noseglinkedit
-@item -pagezero_size
-@item -prebind
-@item -prebind_all_twolevel_modules
-@item -private_bundle
-@item -read_only_relocs
-@item -sectalign
-@item -sectobjectsymbols
-@item -whyload
-@item -seg1addr
-@item -sectcreate
-@item -sectobjectsymbols
-@item -sectorder
-@item -seg_addr_table
-@item -seg_addr_table_filename
-@item -seglinkedit
-@item -segprot
-@item -segs_read_only_addr
-@item -segs_read_write_addr
-@item -single_module
-@item -static
-@item -sub_library
-@item -sub_umbrella
-@item -twolevel_namespace
-@item -umbrella
-@item -undefined
-@item -unexported_symbols_list
-@item -weak_reference_mismatches
-@item -whatsloaded
+@itemx -arch_only
+
+@itemx -client_name
+@itemx -compatibility_version
+@itemx -current_version
+@itemx -dependency-file
+@itemx -dylib_file
+@itemx -dylinker_install_name
+@itemx -dynamic
+@itemx -dynamiclib
+@itemx -exported_symbols_list
+@itemx -filelist
+@itemx -flat_namespace
+@itemx -force_cpusubtype_ALL
+@itemx -force_flat_namespace
+@itemx -headerpad_max_install_names
+@itemx -image_base
+@itemx -init
+@itemx -install_name
+@itemx -keep_private_externs
+@itemx -multi_module
+@itemx -multiply_defined
+@itemx -multiply_defined_unused
+@itemx -noall_load
+@itemx -nofixprebinding
+@itemx -nomultidefs
+@itemx -noprebind
+@itemx -noseglinkedit
+@itemx -pagezero_size
+@itemx -prebind
+@itemx -prebind_all_twolevel_modules
+@itemx -private_bundle
+@itemx -read_only_relocs
+@itemx -sectalign
+@itemx -sectobjectsymbols
+@itemx -whyload
+@itemx -seg1addr
+@itemx -sectcreate
+@itemx -sectobjectsymbols
+@itemx -sectorder
+@itemx -seg_addr_table
+@itemx -seg_addr_table_filename
+@itemx -seglinkedit
+@itemx -segprot
+@itemx -segs_read_only_addr
+@itemx -segs_read_write_addr
+@itemx -single_module
+@itemx -static
+@itemx -sub_library
+@itemx -sub_umbrella
+@itemx -twolevel_namespace
+@itemx -umbrella
+@itemx -undefined
+@itemx -unexported_symbols_list
+@itemx -weak_reference_mismatches
+@itemx -whatsloaded
@opindex allowable_client
-@opindex arch_only
+@opindex arch_only
@opindex client_name
@opindex compatibility_version
@opindex current_version
@opindex dynamic
@opindex dynamiclib
@opindex exported_symbols_list
-@opindex filelist
-@opindex flat_namespace
+@opindex filelist
+@opindex flat_namespace
@opindex force_cpusubtype_ALL
@opindex force_flat_namespace
@opindex headerpad_max_install_names
@opindex image_base
-@opindex init
+@opindex init
@opindex install_name
@opindex keep_private_externs
-@opindex multi_module
+@opindex multi_module
@opindex multiply_defined
-@opindex multiply_defined_unused
-@opindex noall_load
-@opindex nomultidefs
+@opindex multiply_defined_unused
+@opindex noall_load
+@opindex nofixprebinding
+@opindex nomultidefs
@opindex noprebind
-@opindex noseglinkedit
+@opindex noseglinkedit
@opindex pagezero_size
@opindex prebind
@opindex prebind_all_twolevel_modules
-@opindex private_bundle
+@opindex private_bundle
@opindex read_only_relocs
-@opindex sectalign
-@opindex sectobjectsymbols
-@opindex whyload
+@opindex sectalign
+@opindex sectobjectsymbols
+@opindex whyload
@opindex seg1addr
-@opindex sectcreate
-@opindex sectobjectsymbols
-@opindex sectorder
+@opindex sectcreate
+@opindex sectobjectsymbols
+@opindex sectorder
@opindex seg_addr_table
@opindex seg_addr_table_filename
@opindex seglinkedit
@opindex weak_reference_mismatches
@opindex whatsloaded
-This options are available for Darwin linker. Darwin linker man page
+These options are available for Darwin linker. Darwin linker man page
describes them in detail.
@end table
-@node RT Options
-@subsection IBM RT Options
-@cindex RT options
-@cindex IBM RT options
-
-These @samp{-m} options are defined for the IBM RT PC:
-
-@table @gcctabopt
-@item -min-line-mul
-@opindex min-line-mul
-Use an in-line code sequence for integer multiplies. This is the
-default.
-
-@item -mcall-lib-mul
-@opindex mcall-lib-mul
-Call @code{lmul$$} for integer multiples.
-
-@item -mfull-fp-blocks
-@opindex mfull-fp-blocks
-Generate full-size floating point data blocks, including the minimum
-amount of scratch space recommended by IBM@. This is the default.
-
-@item -mminimum-fp-blocks
-@opindex mminimum-fp-blocks
-Do not include extra scratch space in floating point data blocks. This
-results in smaller code, but slower execution, since scratch space must
-be allocated dynamically.
-
-@cindex @file{stdarg.h} and RT PC
-@item -mfp-arg-in-fpregs
-@opindex mfp-arg-in-fpregs
-Use a calling sequence incompatible with the IBM calling convention in
-which floating point arguments are passed in floating point registers.
-Note that @code{stdarg.h} will not work with floating point operands
-if this option is specified.
-
-@item -mfp-arg-in-gregs
-@opindex mfp-arg-in-gregs
-Use the normal calling convention for floating point arguments. This is
-the default.
-
-@item -mhc-struct-return
-@opindex mhc-struct-return
-Return structures of more than one word in memory, rather than in a
-register. This provides compatibility with the MetaWare HighC (hc)
-compiler. Use the option @option{-fpcc-struct-return} for compatibility
-with the Portable C Compiler (pcc).
-
-@item -mnohc-struct-return
-@opindex mnohc-struct-return
-Return some structures of more than one word in registers, when
-convenient. This is the default. For compatibility with the
-IBM-supplied compilers, use the option @option{-fpcc-struct-return} or the
-option @option{-mhc-struct-return}.
-@end table
-
@node MIPS Options
@subsection MIPS Options
@cindex MIPS options
-These @samp{-m} options are defined for the MIPS family of computers:
-
@table @gcctabopt
+@item -EB
+@opindex EB
+Generate big-endian code.
+
+@item -EL
+@opindex EL
+Generate little-endian code. This is the default for @samp{mips*el-*-*}
+configurations.
+
@item -march=@var{arch}
@opindex march
Generate code that will run on @var{arch}, which can be the name of a
@samp{4kc}, @samp{4kp}, @samp{5kc}, @samp{20kc},
@samp{m4k},
@samp{r2000}, @samp{r3000}, @samp{r3900}, @samp{r4000}, @samp{r4400},
-@samp{r4600}, @samp{r4650}, @samp{r6000}, @samp{r8000},
+@samp{r4600}, @samp{r4650}, @samp{r6000}, @samp{r8000}, @samp{rm7000},
+@samp{rm9000},
@samp{orion},
@samp{sb1},
-@samp{vr4100}, @samp{vr4300}, and @samp{vr5000}.
+@samp{vr4100}, @samp{vr4111}, @samp{vr4120}, @samp{vr4300},
+@samp{vr5000}, @samp{vr5400} and @samp{vr5500}.
The special value @samp{from-abi} selects the
most compatible architecture for the selected ABI (that is,
@samp{mips1} for 32-bit ABIs and @samp{mips3} for 64-bit ABIs)@.
@opindex mips64
Equivalent to @samp{-march=mips64}.
-@item -mfused-madd
-@itemx -mno-fused-madd
-@opindex mfused-madd
-@opindex mno-fused-madd
-Generate code that uses (does not use) the floating point multiply and
-accumulate instructions, when they are available. These instructions
-are generated by default if they are available, but this may be
-undesirable if the extra precision causes problems or on certain chips
-in the mode where denormals are rounded to zero where denormals
-generated by multiply and accumulate instructions cause exceptions
-anyway.
+@item -mips16
+@itemx -mno-mips16
+@opindex mips16
+@opindex mno-mips16
+Use (do not use) the MIPS16 ISA.
-@item -mfp32
-@opindex mfp32
-Assume that floating point registers are 32 bits wide.
+@item -mabi=32
+@itemx -mabi=o64
+@itemx -mabi=n32
+@itemx -mabi=64
+@itemx -mabi=eabi
+@opindex mabi=32
+@opindex mabi=o64
+@opindex mabi=n32
+@opindex mabi=64
+@opindex mabi=eabi
+Generate code for the given ABI@.
-@item -mfp64
-@opindex mfp64
-Assume that floating point registers are 64 bits wide.
+Note that the EABI has a 32-bit and a 64-bit variant. GCC normally
+generates 64-bit code when you select a 64-bit architecture, but you
+can use @option{-mgp32} to get 32-bit code instead.
+
+@item -mabicalls
+@itemx -mno-abicalls
+@opindex mabicalls
+@opindex mno-abicalls
+Generate (do not generate) SVR4-style position-independent code.
+@option{-mabicalls} is the default for SVR4-based systems.
+
+@item -mxgot
+@itemx -mno-xgot
+@opindex mxgot
+@opindex mno-xgot
+Lift (do not lift) the usual restrictions on the size of the global
+offset table.
+
+GCC normally uses a single instruction to load values from the GOT.
+While this is relatively efficient, it will only work if the GOT
+is smaller than about 64k. Anything larger will cause the linker
+to report an error such as:
+
+@cindex relocation truncated to fit (MIPS)
+@smallexample
+relocation truncated to fit: R_MIPS_GOT16 foobar
+@end smallexample
+
+If this happens, you should recompile your code with @option{-mxgot}.
+It should then work with very large GOTs, although it will also be
+less efficient, since it will take three instructions to fetch the
+value of a global symbol.
+
+Note that some linkers can create multiple GOTs. If you have such a
+linker, you should only need to use @option{-mxgot} when a single object
+file accesses more than 64k's worth of GOT entries. Very few do.
+
+These options have no effect unless GCC is generating position
+independent code.
+
+@item -membedded-pic
+@itemx -mno-embedded-pic
+@opindex membedded-pic
+@opindex mno-embedded-pic
+Generate (do not generate) position-independent code suitable for some
+embedded systems. All calls are made using PC relative addresses, and
+all data is addressed using the $gp register. No more than 65536
+bytes of global data may be used. This requires GNU as and GNU ld,
+which do most of the work.
@item -mgp32
@opindex mgp32
-Assume that general purpose registers are 32 bits wide.
+Assume that general-purpose registers are 32 bits wide.
@item -mgp64
@opindex mgp64
-Assume that general purpose registers are 64 bits wide.
+Assume that general-purpose registers are 64 bits wide.
+
+@item -mfp32
+@opindex mfp32
+Assume that floating-point registers are 32 bits wide.
+
+@item -mfp64
+@opindex mfp64
+Assume that floating-point registers are 64 bits wide.
+
+@item -mhard-float
+@opindex mhard-float
+Use floating-point coprocessor instructions.
+
+@item -msoft-float
+@opindex msoft-float
+Do not use floating-point coprocessor instructions. Implement
+floating-point calculations using library calls instead.
+
+@item -msingle-float
+@opindex msingle-float
+Assume that the floating-point coprocessor only supports single-precision
+operations.
+
+@itemx -mdouble-float
+@opindex mdouble-float
+Assume that the floating-point coprocessor supports double-precision
+operations. This is the default.
@item -mint64
@opindex mint64
-Force int and long types to be 64 bits wide. See @option{-mlong32} for an
-explanation of the default, and the width of pointers.
+Force @code{int} and @code{long} types to be 64 bits wide. See
+@option{-mlong32} for an explanation of the default and the way
+that the pointer size is determined.
@item -mlong64
@opindex mlong64
-Force long types to be 64 bits wide. See @option{-mlong32} for an
-explanation of the default, and the width of pointers.
+Force @code{long} types to be 64 bits wide. See @option{-mlong32} for
+an explanation of the default and the way that the pointer size is
+determined.
@item -mlong32
@opindex mlong32
-Force long, int, and pointer types to be 32 bits wide.
+Force @code{long}, @code{int}, and pointer types to be 32 bits wide.
-The default size of ints, longs and pointers depends on the ABI@. All
-the supported ABIs use 32-bit ints. The n64 ABI uses 64-bit longs, as
-does the 64-bit Cygnus EABI; the others use 32-bit longs. Pointers
-are the same size as longs, or the same size as integer registers,
-whichever is smaller.
+The default size of @code{int}s, @code{long}s and pointers depends on
+the ABI@. All the supported ABIs use 32-bit @code{int}s. The n64 ABI
+uses 64-bit @code{long}s, as does the 64-bit EABI; the others use
+32-bit @code{long}s. Pointers are the same size as @code{long}s,
+or the same size as integer registers, whichever is smaller.
-@item -mabi=32
-@itemx -mabi=o64
-@itemx -mabi=n32
-@itemx -mabi=64
-@itemx -mabi=eabi
-@itemx -mabi=meabi
-@opindex mabi=32
-@opindex mabi=o64
-@opindex mabi=n32
-@opindex mabi=64
-@opindex mabi=eabi
-@opindex mabi=meabi
-Generate code for the given ABI@.
+@item -G @var{num}
+@opindex G
+@cindex smaller data references (MIPS)
+@cindex gp-relative references (MIPS)
+Put global and static items less than or equal to @var{num} bytes into
+the small data or bss section instead of the normal data or bss section.
+This allows the data to be accessed using a single instruction.
-Note that there are two embedded ABIs: @option{-mabi=eabi}
-selects the one defined by Cygnus while @option{-meabi=meabi}
-selects the one defined by MIPS@. Both these ABIs have
-32-bit and 64-bit variants. Normally, GCC will generate
-64-bit code when you select a 64-bit architecture, but you
-can use @option{-mgp32} to get 32-bit code instead.
+All modules should be compiled with the same @option{-G @var{num}}
+value.
-@item -mabi-fake-default
-@opindex mabi-fake-default
-You don't want to know what this option does. No, really. I mean
-it. Move on to the next option.
-
-What? You're still here? Oh, well@enddots{} Ok, here's the deal. GCC
-wants the default set of options to get the root of the multilib tree,
-and the shared library SONAMEs without any multilib-indicating
-suffixes. This is not convenience for @samp{mips64-linux-gnu}, since
-we want to default to the N32 ABI, while still being binary-compatible
-with @samp{mips-linux-gnu} if you stick to the O32 ABI@. Being
-binary-compatible means shared libraries should have the same SONAMEs,
-and libraries should live in the same location. Having O32 libraries
-in a sub-directory named say @file{o32} is not acceptable.
-
-So we trick GCC into believing that O32 is the default ABI, except
-that we override the default with some internal command-line
-processing magic. Problem is, if we stopped at that, and you then
-created a multilib-aware package that used the output of @command{gcc
--print-multi-lib} to decide which multilibs to build, and how, and
-you'd find yourself in an awkward situation when you found out that
-some of the options listed ended up mapping to the same multilib, and
-none of your libraries was actually built for the multilib that
-@option{-print-multi-lib} claims to be the default. So we added this
-option that disables the default switcher, falling back to GCC's
-original notion of the default library. Confused yet?
-
-For short: don't ever use this option, unless you find it in the list
-of additional options to be used when building for multilibs, in the
-output of @option{gcc -print-multi-lib}.
-
-@item -mmips-as
-@opindex mmips-as
-Generate code for the MIPS assembler, and invoke @file{mips-tfile} to
-add normal debug information. This is the default for all
-platforms except for the OSF/1 reference platform, using the OSF/rose
-object format. If the either of the @option{-gstabs} or @option{-gstabs+}
-switches are used, the @file{mips-tfile} program will encapsulate the
-stabs within MIPS ECOFF@.
+@item -membedded-data
+@itemx -mno-embedded-data
+@opindex membedded-data
+@opindex mno-embedded-data
+Allocate variables to the read-only data section first if possible, then
+next in the small data section if possible, otherwise in data. This gives
+slightly slower code than the default, but reduces the amount of RAM required
+when executing, and thus may be preferred for some embedded systems.
-@item -mgas
-@opindex mgas
-Generate code for the GNU assembler. This is the default on the OSF/1
-reference platform, using the OSF/rose object format. Also, this is
-the default if the configure option @option{--with-gnu-as} is used.
+@item -muninit-const-in-rodata
+@itemx -mno-uninit-const-in-rodata
+@opindex muninit-const-in-rodata
+@opindex mno-uninit-const-in-rodata
+Put uninitialized @code{const} variables in the read-only data section.
+This option is only meaningful in conjunction with @option{-membedded-data}.
@item -msplit-addresses
@itemx -mno-split-addresses
@opindex msplit-addresses
@opindex mno-split-addresses
-Generate code to load the high and low parts of address constants separately.
-This allows GCC to optimize away redundant loads of the high order
-bits of addresses. This optimization requires GNU as and GNU ld.
-This optimization is enabled by default for some embedded targets where
-GNU as and GNU ld are standard.
+Enable (disable) use of the @code{%hi()} and @code{%lo()} assembler
+relocation operators. This option has been superceded by
+@option{-mexplicit-relocs} but is retained for backwards compatibility.
+
+@item -mexplicit-relocs
+@itemx -mno-explicit-relocs
+@opindex mexplicit-relocs
+@opindex mno-explicit-relocs
+Use (do not use) assembler relocation operators when dealing with symbolic
+addresses. The alternative, selected by @option{-mno-explicit-relocs},
+is to use assembler macros instead.
+
+@option{-mexplicit-relocs} is usually the default if GCC was
+configured to use an assembler that supports relocation operators.
+However, there are two exceptions:
+
+@itemize @bullet
+@item
+GCC is not yet able to generate explicit relocations for the combination
+of @option{-mabi=64} and @option{-mno-abicalls}. This will be addressed
+in a future release.
+
+@item
+The combination of @option{-mabicalls} and @option{-fno-unit-at-a-time}
+implies @option{-mno-explicit-relocs} unless explicitly overridden.
+This is because, when generating abicalls, the choice of relocation
+depends on whether a symbol is local or global. In some rare cases,
+GCC will not be able to decide this until the whole compilation unit
+has been read.
+@end itemize
@item -mrnames
@itemx -mno-rnames
@opindex mrnames
@opindex mno-rnames
-The @option{-mrnames} switch says to output code using the MIPS software
-names for the registers, instead of the hardware names (ie, @var{a0}
-instead of @var{$4}). The only known assembler that supports this option
-is the Algorithmics assembler.
-
-@item -mgpopt
-@itemx -mno-gpopt
-@opindex mgpopt
-@opindex mno-gpopt
-The @option{-mgpopt} switch says to write all of the data declarations
-before the instructions in the text section, this allows the MIPS
-assembler to generate one word memory references instead of using two
-words for short global or static data items. This is on by default if
-optimization is selected.
+Generate (do not generate) code that refers to registers using their
+software names. The default is @option{-mno-rnames}, which tells GCC
+to use hardware names like @samp{$4} instead of software names like
+@samp{a0}. The only assembler known to support @option{-rnames} is
+the Algorithmics assembler.
+
+@item -mcheck-zero-division
+@itemx -mno-check-zero-division
+@opindex mcheck-zero-division
+@opindex mno-check-zero-division
+Trap (do not trap) on integer division by zero. The default is
+@option{-mcheck-zero-division}.
@item -mmemcpy
@itemx -mno-memcpy
@opindex mmemcpy
@opindex mno-memcpy
-The @option{-mmemcpy} switch makes all block moves call the appropriate
-string function (@samp{memcpy} or @samp{bcopy}) instead of possibly
-generating inline code.
-
-@item -mmips-tfile
-@itemx -mno-mips-tfile
-@opindex mmips-tfile
-@opindex mno-mips-tfile
-The @option{-mno-mips-tfile} switch causes the compiler not
-postprocess the object file with the @file{mips-tfile} program,
-after the MIPS assembler has generated it to add debug support. If
-@file{mips-tfile} is not run, then no local variables will be
-available to the debugger. In addition, @file{stage2} and
-@file{stage3} objects will have the temporary file names passed to the
-assembler embedded in the object file, which means the objects will
-not compare the same. The @option{-mno-mips-tfile} switch should only
-be used when there are bugs in the @file{mips-tfile} program that
-prevents compilation.
-
-@item -msoft-float
-@opindex msoft-float
-Generate output containing library calls for floating point.
-@strong{Warning:} the requisite libraries are not part of GCC@.
-Normally the facilities of the machine's usual C compiler are used, but
-this can't be done directly in cross-compilation. You must make your
-own arrangements to provide suitable library functions for
-cross-compilation.
-
-@item -mhard-float
-@opindex mhard-float
-Generate output containing floating point instructions. This is the
-default if you use the unmodified sources.
-
-@item -mabicalls
-@itemx -mno-abicalls
-@opindex mabicalls
-@opindex mno-abicalls
-Emit (or do not emit) the pseudo operations @samp{.abicalls},
-@samp{.cpload}, and @samp{.cprestore} that some System V.4 ports use for
-position independent code.
+Force (do not force) the use of @code{memcpy()} for non-trivial block
+moves. The default is @option{-mno-memcpy}, which allows GCC to inline
+most constant-sized copies.
@item -mlong-calls
@itemx -mno-long-calls
@opindex mlong-calls
@opindex mno-long-calls
-Do all calls with the @samp{JALR} instruction, which requires
-loading up a function's address into a register before the call.
-You need to use this switch, if you call outside of the current
-512 megabyte segment to functions that are not through pointers.
-
-@item -mhalf-pic
-@itemx -mno-half-pic
-@opindex mhalf-pic
-@opindex mno-half-pic
-Put pointers to extern references into the data section and load them
-up, rather than put the references in the text section.
-
-@item -membedded-pic
-@itemx -mno-embedded-pic
-@opindex membedded-pic
-@opindex mno-embedded-pic
-Generate PIC code suitable for some embedded systems. All calls are
-made using PC relative address, and all data is addressed using the $gp
-register. No more than 65536 bytes of global data may be used. This
-requires GNU as and GNU ld which do most of the work. This currently
-only works on targets which use ECOFF; it does not work with ELF@.
-
-@item -membedded-data
-@itemx -mno-embedded-data
-@opindex membedded-data
-@opindex mno-embedded-data
-Allocate variables to the read-only data section first if possible, then
-next in the small data section if possible, otherwise in data. This gives
-slightly slower code than the default, but reduces the amount of RAM required
-when executing, and thus may be preferred for some embedded systems.
+Disable (do not disable) use of the @code{jal} instruction. Calling
+functions using @code{jal} is more efficient but requires the caller
+and callee to be in the same 256 megabyte segment.
-@item -muninit-const-in-rodata
-@itemx -mno-uninit-const-in-rodata
-@opindex muninit-const-in-rodata
-@opindex mno-uninit-const-in-rodata
-When used together with @option{-membedded-data}, it will always store uninitialized
-const variables in the read-only data section.
-
-@item -msingle-float
-@itemx -mdouble-float
-@opindex msingle-float
-@opindex mdouble-float
-The @option{-msingle-float} switch tells gcc to assume that the floating
-point coprocessor only supports single precision operations, as on the
-@samp{r4650} chip. The @option{-mdouble-float} switch permits gcc to use
-double precision operations. This is the default.
+This option has no effect on abicalls code. The default is
+@option{-mno-long-calls}.
@item -mmad
@itemx -mno-mad
@opindex mmad
@opindex mno-mad
-Permit use of the @samp{mad}, @samp{madu} and @samp{mul} instructions,
-as on the @samp{r4650} chip.
-
-@item -m4650
-@opindex m4650
-Turns on @option{-msingle-float}, @option{-mmad}, and, at least for now,
-@option{-mcpu=r4650}.
-
-@item -mips16
-@itemx -mno-mips16
-@opindex mips16
-@opindex mno-mips16
-Enable 16-bit instructions.
+Enable (disable) use of the @code{mad}, @code{madu} and @code{mul}
+instructions, as provided by the R4650 ISA.
-@item -mentry
-@opindex mentry
-Use the entry and exit pseudo ops. This option can only be used with
-@option{-mips16}.
-
-@item -EL
-@opindex EL
-Compile code for the processor in little endian mode.
-The requisite libraries are assumed to exist.
-
-@item -EB
-@opindex EB
-Compile code for the processor in big endian mode.
-The requisite libraries are assumed to exist.
+@item -mfused-madd
+@itemx -mno-fused-madd
+@opindex mfused-madd
+@opindex mno-fused-madd
+Enable (disable) use of the floating point multiply-accumulate
+instructions, when they are available. The default is
+@option{-mfused-madd}.
-@item -G @var{num}
-@opindex G
-@cindex smaller data references (MIPS)
-@cindex gp-relative references (MIPS)
-Put global and static items less than or equal to @var{num} bytes into
-the small data or bss sections instead of the normal data or bss
-section. This allows the assembler to emit one word memory reference
-instructions based on the global pointer (@var{gp} or @var{$28}),
-instead of the normal two words used. By default, @var{num} is 8 when
-the MIPS assembler is used, and 0 when the GNU assembler is used. The
-@option{-G @var{num}} switch is also passed to the assembler and linker.
-All modules should be compiled with the same @option{-G @var{num}}
-value.
+When multiply-accumulate instructions are used, the intermediate
+product is calculated to infinite precision and is not subject to
+the FCSR Flush to Zero bit. This may be undesirable in some
+circumstances.
@item -nocpp
@opindex nocpp
Tell the MIPS assembler to not run its preprocessor over user
assembler files (with a @samp{.s} suffix) when assembling them.
-@item -mfix7000
-@opindex mfix7000
-Pass an option to gas which will cause nops to be inserted if
-the read of the destination register of an mfhi or mflo instruction
-occurs in the following two instructions.
-
-@item -no-crt0
-@opindex no-crt0
-Do not include the default crt0.
+@item -mfix-sb1
+@itemx -mno-fix-sb1
+@opindex mfix-sb1
+Work around certain SB-1 CPU core errata.
+(This flag currently works around the SB-1 revision 2
+``F1'' and ``F2'' floating point errata.)
@item -mflush-func=@var{func}
@itemx -mno-flush-func
@opindex mtune
Tune to @var{cpu-type} everything applicable about the generated code, except
for the ABI and the set of available instructions. The choices for
-@var{cpu-type} are @samp{i386}, @samp{i486}, @samp{i586}, @samp{i686},
-@samp{pentium}, @samp{pentium-mmx}, @samp{pentiumpro}, @samp{pentium2},
-@samp{pentium3}, @samp{pentium4}, @samp{k6}, @samp{k6-2}, @samp{k6-3},
-@samp{athlon}, @samp{athlon-tbird}, @samp{athlon-4}, @samp{athlon-xp},
-@samp{athlon-mp}, @samp{winchip-c6}, @samp{winchip2}, @samp{k8}, @samp{c3}
-and @samp{c3-2}.
+@var{cpu-type} are:
+@table @emph
+@item i386
+Original Intel's i386 CPU.
+@item i486
+Intel's i486 CPU. (No scheduling is implemented for this chip.)
+@item i586, pentium
+Intel Pentium CPU with no MMX support.
+@item pentium-mmx
+Intel PentiumMMX CPU based on Pentium core with MMX instruction set support.
+@item i686, pentiumpro
+Intel PentiumPro CPU.
+@item pentium2
+Intel Pentium2 CPU based on PentiumPro core with MMX instruction set support.
+@item pentium3
+Intel Pentium3 CPU based on PentiumPro core with MMX and SSE instruction set
+support.
+@item pentium4
+Intel Pentium4 CPU with MMX, SSE and SSE2 instruction set support.
+@item k6
+AMD K6 CPU with MMX instruction set support.
+@item k6-2, k6-3
+Improved versions of AMD K6 CPU with MMX and 3dNOW! instruction set support.
+@item athlon, athlon-tbird
+AMD Athlon CPU with MMX, 3dNOW!, enhanced 3dNOW! and SSE prefetch instructions
+support.
+@item athlon-4, athlon-xp, athlon-mp
+Improved AMD Athlon CPU with MMX, 3dNOW!, enhanced 3dNOW! and full SSE
+instruction set support.
+@item k8, opteron, athlon64, athlon-fx
+AMD K8 core based CPUs with x86-64 instruction set support. (This supersets
+MMX, SSE, SSE2, 3dNOW!, enhanced 3dNOW! and 64-bit instruction set extensions.)
+@item winchip-c6
+IDT Winchip C6 CPU, dealt in same way as i486 with additional MMX instruction
+set support.
+@item winchip2
+IDT Winchip2 CPU, dealt in same way as i486 with additional MMX and 3dNOW!
+instruction set support.
+@item c3
+Via C3 CPU with MMX and 3dNOW! instruction set support. (No scheduling is
+implemented for this chip.)
+@item c3-2
+Via C3-2 CPU with MMX and SSE instruction set support. (No scheduling is
+implemented for this chip.)
+@end table
While picking a specific @var{cpu-type} will schedule things appropriately
for that particular chip, the compiler will not generate any code that
does not run on the i386 without the @option{-march=@var{cpu-type}} option
-being used. @samp{i586} is equivalent to @samp{pentium} and @samp{i686}
-is equivalent to @samp{pentiumpro}. @samp{k6} and @samp{athlon} are the
-AMD chips as opposed to the Intel ones.
+being used.
@item -march=@var{cpu-type}
@opindex march
This is the default choice for x86-64 compiler.
+@item pni
+Use all SSE extensions enabled by @option{-msse2} as well as the new
+SSE extensions in Prescott New Instructions. @option{-mpni} also
+enables 2 builtin functions, @code{__builtin_ia32_monitor} and
+@code{__builtin_ia32_mwait}, for new instructions @code{monitor} and
+@code{mwait}.
+
@item sse,387
Attempt to utilize both instruction sets at once. This effectively double the
amount of available registers and on chips with separate execution units for
without that switch.
@item -m96bit-long-double
-@item -m128bit-long-double
+@itemx -m128bit-long-double
@opindex m96bit-long-double
@opindex m128bit-long-double
-These switches control the size of @code{long double} type. The i386
-application binary interface specifies the size to be 96 bits,
+These switches control the size of @code{long double} type. The i386
+application binary interface specifies the size to be 96 bits,
so @option{-m96bit-long-double} is the default in 32 bit mode.
Modern architectures (Pentium and newer) would prefer @code{long double}
-to be aligned to an 8 or 16 byte boundary. In arrays or structures
-conforming to the ABI, this would not be possible. So specifying a
+to be aligned to an 8 or 16 byte boundary. In arrays or structures
+conforming to the ABI, this would not be possible. So specifying a
@option{-m128bit-long-double} will align @code{long double}
to a 16 byte boundary by padding the @code{long double} with an additional
-32 bit zero.
+32 bit zero.
In the x86-64 compiler, @option{-m128bit-long-double} is the default choice as
its ABI specifies that @code{long double} is to be aligned on 16 byte boundary.
-
+
Notice that neither of these options enable any extra precision over the x87
-standard of 80 bits for a @code{long double}.
+standard of 80 bits for a @code{long double}.
@strong{Warning:} if you override the default value for your target ABI, the
structures and arrays containing @code{long double} will change their size as
@itemx -mno-sse
@item -msse2
@itemx -mno-sse2
+@item -mpni
+@itemx -mno-pni
@item -m3dnow
@itemx -mno-3dnow
@opindex mmmx
@table @samp
@item ev4
-@item ev45
+@itemx ev45
@itemx 21064
Schedules as an EV4 and has no instruction set extensions.
Schedules as an EV6 and supports the BWX, FIX, and MAX extensions.
@item ev67
-@item 21264a
+@itemx 21264a
Schedules as an EV6 and supports the BWX, CIX, FIX, and MAX extensions.
@end table
@opindex mrelax
Shorten some address references at link time, when possible; uses the
linker option @option{-relax}. @xref{H8/300,, @code{ld} and the H8/300,
-ld.info, Using ld}, for a fuller description.
+ld, Using ld}, for a fuller description.
@item -mh
@opindex mh
TMS320C40.
@item -mbig-memory
-@item -mbig
+@itemx -mbig
@itemx -msmall-memory
@itemx -msmall
@opindex mbig-memory
@itemx -mprolog-function
@opindex mno-prolog-function
@opindex mprolog-function
-Do not use (do use) external functions to save and restore registers at
-the prolog and epilog of a function. The external functions are slower,
-but use less code space if more than one function saves the same number
-of registers. The @option{-mprolog-function} option is on by default if
-you optimize.
+Do not use (do use) external functions to save and restore registers
+at the prologue and epilogue of a function. The external functions
+are slower, but use less code space if more than one function saves
+the same number of registers. The @option{-mprolog-function} option
+is on by default if you optimize.
@item -mspace
@opindex mspace
@item -mno-app-regs
@opindex mno-app-regs
This option will cause r2 and r5 to be treated as fixed registers.
-
+
+@item -mv850e1
+@opindex mv850e1
+Specify that the target processor is the V850E1. The preprocessor
+constants @samp{__v850e1__} and @samp{__v850e__} will be defined if
+this option is used.
+
@item -mv850e
@opindex mv850e
Specify that the target processor is the V850E. The preprocessor
constant @samp{__v850e__} will be defined if this option is used.
-If neither @option{-mv850} nor @option{-mv850e} are defined
-then a default target processor will be chosen and the relevant
-@samp{__v850*__} preprocessor constant will be defined.
+If neither @option{-mv850} nor @option{-mv850e} nor @option{-mv850e1}
+are defined then a default target processor will be chosen and the
+relevant @samp{__v850*__} preprocessor constant will be defined.
The preprocessor constants @samp{__v850} and @samp{__v851__} are always
defined, regardless of which processor variant is the target.
@item -mdisable-callt
@opindex mdisable-callt
This option will suppress generation of the CALLT instruction for the
-v850e flavors of the v850 architecture. The default is
+v850e and v850e1 flavors of the v850 architecture. The default is
@option{-mno-disable-callt} which allows the CALLT instruction to be used.
@end table
@item -mlittle-endian
@opindex mlittle-endian
Generate code for a little endian target. This is the default for AIX5
-and Linux.
+and GNU/Linux.
@item -mgnu-as
@itemx -mno-gnu-as
@opindex m64
@opindex m31
When @option{-m31} is specified, generate code compliant to the
-Linux for S/390 ABI@. When @option{-m64} is specified, generate
-code compliant to the Linux for zSeries ABI@. This allows GCC in
+GNU/Linux for S/390 ABI@. When @option{-m64} is specified, generate
+code compliant to the GNU/Linux for zSeries ABI@. This allows GCC in
particular to generate 64-bit instructions. For the @samp{s390}
targets, the default is @option{-m31}, while the @samp{s390x}
targets default to @option{-m64}.
@itemx -mesa
@opindex mzarch
@opindex mesa
-When @option{-mzarch} is specified, generate code using the
-instructions available on z/Architecture.
-When @option{-mesa} is specified, generate code using the
+When @option{-mzarch} is specified, generate code using the
+instructions available on z/Architecture.
+When @option{-mesa} is specified, generate code using the
instructions available on ESA/390. Note that @option{-mesa} is
not possible with @option{-m64}.
-For the @samp{s390} targets, the default is @option{-mesa},
-while the @samp{s390x} targets default to @option{-mzarch}.
+When generating code compliant to the GNU/Linux for S/390 ABI,
+the default is @option{-mesa}. When generating code compliant
+to the GNU/Linux for zSeries ABI, the default is @option{-mzarch}.
@item -mmvcle
@itemx -mno-mvcle
Print (or do not print) additional debug information when compiling.
The default is to not print debug information.
-@item -march=@var{arch}
+@item -march=@var{cpu-type}
@opindex march
-Generate code that will run on @var{arch}, which is the name of system
+Generate code that will run on @var{cpu-type}, which is the name of a system
representing a certain processor type. Possible values for
-@var{cpu-type} are @samp{g5}, @samp{g6} and @samp{z900}.
+@var{cpu-type} are @samp{g5}, @samp{g6}, @samp{z900}, and @samp{z990}.
+When generating code using the instructions available on z/Architecture,
+the default is @option{-march=z900}. Otherwise, the default is
+@option{-march=g5}.
-@item -mtune=@var{arch}
+@item -mtune=@var{cpu-type}
@opindex mtune
Tune to @var{cpu-type} everything applicable about the generated code,
- except for the ABI and the set of available instructions.
-The list of @var{arch} values is the same as for @option{-march}.
+except for the ABI and the set of available instructions.
+The list of @var{cpu-type} values is the same as for @option{-march}.
+The default is the value used for @option{-march}.
+@item -mfused-madd
+@itemx -mno-fused-madd
+@opindex mfused-madd
+@opindex mno-fused-madd
+Generate code that uses (does not use) the floating point multiply and
+accumulate instructions. These instructions are generated by default if
+hardware floating point is used.
@end table
@node CRIS Options
Use 64-bit @code{float}. This is the default.
@item -mfloat32
-@item -mno-float64
+@itemx -mno-float64
@opindex mfloat32
@opindex mno-float64
Use 32-bit @code{float}.
@subsection Xtensa Options
@cindex Xtensa Options
-The Xtensa architecture is designed to support many different
-configurations. The compiler's default options can be set to match a
-particular Xtensa configuration by copying a configuration file into the
-GCC sources when building GCC@. The options below may be used to
-override the default options.
+These options are supported for Xtensa targets:
@table @gcctabopt
-@item -mbig-endian
-@itemx -mlittle-endian
-@opindex mbig-endian
-@opindex mlittle-endian
-Specify big-endian or little-endian byte ordering for the target Xtensa
-processor.
-
-@item -mdensity
-@itemx -mno-density
-@opindex mdensity
-@opindex mno-density
-Enable or disable use of the optional Xtensa code density instructions.
-
@item -mconst16
@itemx -mno-const16
@opindex mconst16
instructions. The use of @code{CONST16} is enabled by default only if
the @code{L32R} instruction is not available.
-@item -mabs
-@itemx -mno-abs
-@opindex mabs
-@opindex mno-abs
-Enable or disable use of the Xtensa @code{ABS} instruction for absolute
-value operations.
-
-@item -maddx
-@itemx -mno-addx
-@opindex maddx
-@opindex mno-addx
-Enable or disable use of the Xtensa @code{ADDX} and @code{SUBX}
-instructions.
-
-@item -mmac16
-@itemx -mno-mac16
-@opindex mmac16
-@opindex mno-mac16
-Enable or disable use of the Xtensa MAC16 option. When enabled, GCC
-will generate MAC16 instructions from standard C code, with the
-limitation that it will use neither the MR register file nor any
-instruction that operates on the MR registers. When this option is
-disabled, GCC will translate 16-bit multiply/accumulate operations to a
-combination of core instructions and library calls, depending on whether
-any other multiplier options are enabled.
-
-@item -mmul16
-@itemx -mno-mul16
-@opindex mmul16
-@opindex mno-mul16
-Enable or disable use of the 16-bit integer multiplier option. When
-enabled, the compiler will generate 16-bit multiply instructions for
-multiplications of 16 bits or smaller in standard C code. When this
-option is disabled, the compiler will either use 32-bit multiply or
-MAC16 instructions if they are available or generate library calls to
-perform the multiply operations using shifts and adds.
-
-@item -mmul32
-@itemx -mno-mul32
-@opindex mmul32
-@opindex mno-mul32
-Enable or disable use of the 32-bit integer multiplier option. When
-enabled, the compiler will generate 32-bit multiply instructions for
-multiplications of 32 bits or smaller in standard C code. When this
-option is disabled, the compiler will generate library calls to perform
-the multiply operations using either shifts and adds or 16-bit multiply
-instructions if they are available.
-
-@item -mnsa
-@itemx -mno-nsa
-@opindex mnsa
-@opindex mno-nsa
-Enable or disable use of the optional normalization shift amount
-(@code{NSA}) instructions to implement the built-in @code{ffs} function.
-
-@item -mminmax
-@itemx -mno-minmax
-@opindex mminmax
-@opindex mno-minmax
-Enable or disable use of the optional minimum and maximum value
-instructions.
-
-@item -msext
-@itemx -mno-sext
-@opindex msext
-@opindex mno-sext
-Enable or disable use of the optional sign extend (@code{SEXT})
-instruction.
-
-@item -mbooleans
-@itemx -mno-booleans
-@opindex mbooleans
-@opindex mno-booleans
-Enable or disable support for the boolean register file used by Xtensa
-coprocessors. This is not typically useful by itself but may be
-required for other options that make use of the boolean registers (e.g.,
-the floating-point option).
-
-@item -mhard-float
-@itemx -msoft-float
-@opindex mhard-float
-@opindex msoft-float
-Enable or disable use of the floating-point option. When enabled, GCC
-generates floating-point instructions for 32-bit @code{float}
-operations. When this option is disabled, GCC generates library calls
-to emulate 32-bit floating-point operations using integer instructions.
-Regardless of this option, 64-bit @code{double} operations are always
-emulated with calls to library functions.
-
@item -mfused-madd
@itemx -mno-fused-madd
@opindex mfused-madd
@opindex fwrapv
This option instructs the compiler to assume that signed arithmetic
overflow of addition, subtraction and multiplication wraps around
-using twos-complement representation. This flag enables some optimzations
+using twos-complement representation. This flag enables some optimizations
and disables other. This option is enabled by default for the Java
front-end, as required by the Java language specification.
@opindex fno-ident
Ignore the @samp{#ident} directive.
-@item -fno-gnu-linker
-@opindex fno-gnu-linker
-Do not output global initializations (such as C++ constructors and
-destructors) in the form used by the GNU linker (on systems where the GNU
-linker is the standard method of handling them). Use this option when
-you want to use a non-GNU linker, which also requires using the
-@command{collect2} program to make sure the system linker includes
-constructors and destructors. (@command{collect2} is included in the GCC
-distribution.) For systems which @emph{must} use @command{collect2}, the
-compiler driver @command{gcc} is configured to do this automatically.
-
@item -finhibit-size-directive
@opindex finhibit-size-directive
Don't output a @code{.size} assembler directive, or anything else that
the GOT size for the linked executable exceeds a machine-specific
maximum size, you get an error message from the linker indicating that
@option{-fpic} does not work; in that case, recompile with @option{-fPIC}
-instead. (These maximums are 16k on the m88k, 8k on the SPARC, and 32k
+instead. (These maximums are 8k on the SPARC and 32k
on the m68k and RS/6000. The 386 has no such limit.)
Position-independent code requires special support, and therefore works
@opindex fPIC
If supported for the target machine, emit position-independent code,
suitable for dynamic linking and avoiding any limit on the size of the
-global offset table. This option makes a difference on the m68k, m88k,
+global offset table. This option makes a difference on the m68k
and the SPARC.
Position-independent code requires special support, and therefore works
function, so the call site information may not be available to the
profiling functions otherwise.)
-@example
+@smallexample
void __cyg_profile_func_enter (void *this_fn,
void *call_site);
void __cyg_profile_func_exit (void *this_fn,
void *call_site);
-@end example
+@end smallexample
The first argument is the address of the start of the current function,
which may be looked up exactly in the symbol table.
tries looking in the usual places for the subprogram.
The default value of @env{GCC_EXEC_PREFIX} is
-@file{@var{prefix}/lib/gcc-lib/} where @var{prefix} is the value
+@file{@var{prefix}/lib/gcc/} where @var{prefix} is the value
of @code{prefix} when you ran the @file{configure} script.
Other prefixes specified with @option{-B} take precedence over this prefix.
In addition, the prefix is used in an unusual way in finding the
directories to search for header files. For each of the standard
-directories whose name normally begins with @samp{/usr/local/lib/gcc-lib}
+directories whose name normally begins with @samp{/usr/local/lib/gcc}
(more precisely, with the value of @env{GCC_INCLUDE_DIR}), GCC tries
replacing that beginning with the specified prefix to produce an
alternate directory name. Thus, with @option{-Bfoo/}, GCC will search
A precompiled header file will be searched for when @code{#include} is
seen in the compilation. As it searches for the included file
-(@pxref{Search Path,,Search Path,cpp.info,The C Preprocessor}) the
+(@pxref{Search Path,,Search Path,cpp,The C Preprocessor}) the
compiler looks for a precompiled header in each directory just before it
looks for the include file in that directory. The name searched for is
the name specified in the @code{#include} with @samp{.gch} appended. If
the existing @samp{.X} file because it is newer than the source file.
For example:
-@example
+@smallexample
gcc -Dfoo=bar file1.c -aux-info file1.X
protoize *.c
-@end example
+@end smallexample
@noindent
You need to include the special files along with the rest in the
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