@c Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
-@c 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
+@c 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
@c Free Software Foundation, Inc.
@c This is part of the GCC manual.
@c For copying conditions, see the file gcc.texi.
@c man begin COPYRIGHT
Copyright @copyright{} 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
-1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
+1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document
and register usage.
* Environment Variables:: Env vars that affect GCC.
* Precompiled Headers:: Compiling a header once, and using it many times.
-* Running Protoize:: Automatically adding or removing function prototypes.
@end menu
@c man begin OPTIONS
@item Overall Options
@xref{Overall Options,,Options Controlling the Kind of Output}.
@gccoptlist{-c -S -E -o @var{file} -combine -pipe -pass-exit-codes @gol
--x @var{language} -v -### --help@r{[}=@var{class}@r{]} --target-help @gol
+-x @var{language} -v -### --help@r{[}=@var{class}@r{[},@dots{}@r{]]} --target-help @gol
--version -wrapper@@@var{file}}
@item C Language Options
-fno-implement-inlines -fms-extensions @gol
-fno-nonansi-builtins -fno-operator-names @gol
-fno-optional-diags -fpermissive @gol
+-fno-pretty-templates @gol
-frepo -fno-rtti -fstats -ftemplate-depth-@var{n} @gol
-fno-threadsafe-statics -fuse-cxa-atexit -fno-weak -nostdinc++ @gol
-fno-default-inline -fvisibility-inlines-hidden @gol
-Wchar-subscripts -Wclobbered -Wcomment @gol
-Wconversion -Wcoverage-mismatch -Wno-deprecated @gol
-Wno-deprecated-declarations -Wdisabled-optimization @gol
--Wdisallowed-function-list=@var{sym},@var{sym},@dots{} @gol
-Wno-div-by-zero -Wempty-body -Wenum-compare -Wno-endif-labels @gol
-Werror -Werror=* @gol
-Wfatal-errors -Wfloat-equal -Wformat -Wformat=2 @gol
-Wmissing-format-attribute -Wmissing-include-dirs @gol
-Wmissing-noreturn -Wno-mudflap @gol
-Wno-multichar -Wnonnull -Wno-overflow @gol
--Woverlength-strings -Wpacked -Wpadded @gol
+-Woverlength-strings -Wpacked -Wpacked-bitfield-compat -Wpadded @gol
-Wparentheses -Wpedantic-ms-format -Wno-pedantic-ms-format @gol
-Wpointer-arith -Wno-pointer-to-int-cast @gol
-Wredundant-decls @gol
-Wsign-compare -Wsign-conversion -Wstack-protector @gol
-Wstrict-aliasing -Wstrict-aliasing=n @gol
-Wstrict-overflow -Wstrict-overflow=@var{n} @gol
--Wswitch -Wswitch-default -Wswitch-enum @gol
+-Wswitch -Wswitch-default -Wswitch-enum -Wsync-nand @gol
-Wsystem-headers -Wtrigraphs -Wtype-limits -Wundef -Wuninitialized @gol
-Wunknown-pragmas -Wno-pragmas -Wunreachable-code @gol
-Wunused -Wunused-function -Wunused-label -Wunused-parameter @gol
-print-multi-directory -print-multi-lib @gol
-print-prog-name=@var{program} -print-search-dirs -Q @gol
-print-sysroot -print-sysroot-headers-suffix @gol
--save-temps -time}
+-save-temps -save-temps=cwd -save-temps=obj -time}
@item Optimization Options
@xref{Optimize Options,,Options that Control Optimization}.
-fdata-sections -fdce -fdce @gol
-fdelayed-branch -fdelete-null-pointer-checks -fdse -fdse @gol
-fearly-inlining -fexpensive-optimizations -ffast-math @gol
--ffinite-math-only -ffloat-store -fforward-propagate @gol
--ffunction-sections -fgcse -fgcse-after-reload -fgcse-las -fgcse-lm @gol
+-ffinite-math-only -ffloat-store -fexcess-precision=@var{style} @gol
+-fforward-propagate -ffunction-sections @gol
+-fgcse -fgcse-after-reload -fgcse-las -fgcse-lm @gol
-fgcse-sm -fif-conversion -fif-conversion2 -findirect-inlining @gol
-finline-functions -finline-functions-called-once -finline-limit=@var{n} @gol
--finline-small-functions -fipa-cp -fipa-cp-clone -fipa-marix-reorg -fipa-pta @gol
+-finline-small-functions -fipa-cp -fipa-cp-clone -fipa-matrix-reorg -fipa-pta @gol
-fipa-pure-const -fipa-reference -fipa-struct-reorg @gol
--fipa-type-escape -fira -fira-algorithm=@var{algorithm} @gol
--fira-coalesce -fno-ira-share-save-slots @gol
+-fipa-type-escape -fira-algorithm=@var{algorithm} @gol
+-fira-region=@var{region} -fira-coalesce -fno-ira-share-save-slots @gol
-fno-ira-share-spill-slots -fira-verbose=@var{n} @gol
-fivopts -fkeep-inline-functions -fkeep-static-consts @gol
-floop-block -floop-interchange -floop-strip-mine @gol
-freciprocal-math -fregmove -frename-registers -freorder-blocks @gol
-freorder-blocks-and-partition -freorder-functions @gol
-frerun-cse-after-loop -freschedule-modulo-scheduled-loops @gol
--frounding-math -frtl-abstract-sequences -fsched2-use-superblocks @gol
+-frounding-math -fsched2-use-superblocks @gol
-fsched2-use-traces -fsched-spec-load -fsched-spec-load-dangerous @gol
-fsched-stalled-insns-dep[=@var{n}] -fsched-stalled-insns[=@var{n}] @gol
-fschedule-insns -fschedule-insns2 -fsection-anchors -fsee @gol
@emph{AVR Options}
@gccoptlist{-mmcu=@var{mcu} -msize -minit-stack=@var{n} -mno-interrupts @gol
--mcall-prologues -mno-tablejump -mtiny-stack -mint8}
+-mcall-prologues -mtiny-stack -mint8}
@emph{Blackfin Options}
@gccoptlist{-mcpu=@var{cpu}@r{[}-@var{sirevision}@r{]} @gol
-mno-id-shared-library -mshared-library-id=@var{n} @gol
-mleaf-id-shared-library -mno-leaf-id-shared-library @gol
-msep-data -mno-sep-data -mlong-calls -mno-long-calls @gol
--mfast-fp -minline-plt -mmulticore -mcorea -mcoreb -msdram}
+-mfast-fp -minline-plt -mmulticore -mcorea -mcoreb -msdram @gol
+-micplb}
@emph{CRIS Options}
@gccoptlist{-mcpu=@var{cpu} -march=@var{cpu} -mtune=@var{cpu} @gol
@emph{DEC Alpha/VMS Options}
@gccoptlist{-mvms-return-codes}
+@emph{FR30 Options}
+@gccoptlist{-msmall-model -mno-lsim}
+
@emph{FRV Options}
@gccoptlist{-mgpr-32 -mgpr-64 -mfpr-32 -mfpr-64 @gol
-mhard-float -msoft-float @gol
-m96bit-long-double -mregparm=@var{num} -msseregparm @gol
-mveclibabi=@var{type} -mpc32 -mpc64 -mpc80 -mstackrealign @gol
-momit-leaf-frame-pointer -mno-red-zone -mno-tls-direct-seg-refs @gol
--mcmodel=@var{code-model} @gol
+-mcmodel=@var{code-model} -mabi=@var{name} @gol
-m32 -m64 -mlarge-data-threshold=@var{num} @gol
-mfused-madd -mno-fused-madd -msse2avx}
-mmemcpy -mno-memcpy -mlong-calls -mno-long-calls @gol
-mmad -mno-mad -mfused-madd -mno-fused-madd -nocpp @gol
-mfix-r4000 -mno-fix-r4000 -mfix-r4400 -mno-fix-r4400 @gol
--mfix-vr4120 -mno-fix-vr4120 -mfix-vr4130 -mno-fix-vr4130 @gol
--mfix-sb1 -mno-fix-sb1 @gol
+-mfix-r10000 -mno-fix-r10000 -mfix-vr4120 -mno-fix-vr4120 @gol
+-mfix-vr4130 -mno-fix-vr4130 -mfix-sb1 -mno-fix-sb1 @gol
-mflush-func=@var{func} -mno-flush-func @gol
-mbranch-cost=@var{num} -mbranch-likely -mno-branch-likely @gol
-mfp-exceptions -mno-fp-exceptions @gol
-msoft-float -mhard-float -mmultiple -mno-multiple @gol
-msingle-float -mdouble-float -msimple-fpu @gol
-mstring -mno-string -mupdate -mno-update @gol
+-mavoid-indexed-addresses -mno-avoid-indexed-addresses @gol
-mfused-madd -mno-fused-madd -mbit-align -mno-bit-align @gol
-mstrict-align -mno-strict-align -mrelocatable @gol
-mno-relocatable -mrelocatable-lib -mno-relocatable-lib @gol
@emph{x86-64 Options}
See i386 and x86-64 Options.
+@emph{i386 and x86-64 Windows Options}
+@gccoptlist{-mconsole -mcygwin -mno-cygwin -mdll
+-mnop-fun-dllimport -mthread -mwin32 -mwindows}
+
@emph{Xstormy16 Options}
@gccoptlist{-msim}
line options for each tool. For some targets extra target-specific
information may also be printed.
-@item --help=@var{class}@r{[},@var{qualifier}@r{]}
+@item --help=@{@var{class}@r{|[}^@r{]}@var{qualifier}@}@r{[},@dots{}@r{]}
Print (on the standard output) a description of the command line
-options understood by the compiler that fit into a specific class.
-The class can be one of @samp{optimizers}, @samp{warnings}, @samp{target},
-@samp{params}, or @var{language}:
+options understood by the compiler that fit into all specified classes
+and qualifiers. These are the supported classes:
@table @asis
@item @samp{optimizers}
This will display the options that are common to all languages.
@end table
-It is possible to further refine the output of the @option{--help=}
-option by adding a comma separated list of qualifiers after the
-class. These can be any from the following list:
+These are the supported qualifiers:
@table @asis
@item @samp{undocumented}
@end smallexample
The sense of a qualifier can be inverted by prefixing it with the
-@var{^} character, so for example to display all binary warning
+@samp{^} character, so for example to display all binary warning
options (i.e., ones that are either on or off and that do not take an
argument), which have a description the following can be used:
--help=warnings,^joined,^undocumented
@end smallexample
-A class can also be used as a qualifier, although this usually
+The argument to @option{--help=} should not consist solely of inverted
+qualifiers.
+
+Combining several classes is possible, although this usually
restricts the output by so much that there is nothing to display. One
case where it does work however is when one of the classes is
@var{target}. So for example to display all the target-specific
are enabled at @option{-O2} by using:
@smallexample
--O2 --help=optimizers
+-Q -O2 --help=optimizers
@end smallexample
Alternatively you can discover which binary optimizations are enabled
The compiler can accept several base standards, such as @samp{c89} or
@samp{c++98}, and GNU dialects of those standards, such as
-@samp{gnu89} or @samp{gnu++98}. By specifing a base standard, the
+@samp{gnu89} or @samp{gnu++98}. By specifying a base standard, the
compiler will accept all programs following that standard and those
using GNU extensions that do not contradict it. For example,
@samp{-std=c89} turns off certain features of GCC that are
incompatible with ISO C90, such as the @code{asm} and @code{typeof}
keywords, but not other GNU extensions that do not have a meaning in
ISO C90, such as omitting the middle term of a @code{?:}
-expression. On the other hand, by specifing a GNU dialect of a
+expression. On the other hand, by specifying a GNU dialect of a
standard, all features the compiler support are enabled, even when
those features change the meaning of the base standard and some
strict-conforming programs may be rejected. The particular standard
warnings. Thus, using @option{-fpermissive} will allow some
nonconforming code to compile.
+@item -fno-pretty-templates
+@opindex fno-pretty-templates
+When an error message refers to a specialization of a function
+template, the compiler will normally print the signature of the
+template followed by the template arguments and any typedefs or
+typenames in the signature (e.g. @code{void f(T) [with T = int]}
+rather than @code{void f(int)}) so that it's clear which template is
+involved. When an error message refers to a specialization of a class
+template, the compiler will omit any template arguments which match
+the default template arguments for that template. If either of these
+behaviors make it harder to understand the error message rather than
+easier, using @option{-fno-pretty-templates} will disable them.
+
@item -frepo
@opindex frepo
Enable automatic template instantiation at link time. This option also
functions will have linkage like inline functions; they just won't be
inlined by default.
-@item -Wabi @r{(C++ and Objective-C++ only)}
+@item -Wabi @r{(C, Objective-C, C++ and Objective-C++ only)}
@opindex Wabi
@opindex Wno-abi
Warn when G++ generates code that is probably not compatible with the
@end itemize
+It also warns psABI related changes. The known psABI changes at this
+point include:
+
+@itemize @bullet
+
+@item
+For SYSV/x86-64, when passing union with long double, it is changed to
+pass in memory as specified in psABI. For example:
+
+@smallexample
+union U @{
+ long double ld;
+ int i;
+@};
+@end smallexample
+
+@noindent
+@code{union U} will always be passed in memory.
+
+@end itemize
+
@item -Wctor-dtor-privacy @r{(C++ and Objective-C++ only)}
@opindex Wctor-dtor-privacy
@opindex Wno-ctor-dtor-privacy
Warn also about the use of an uncasted @code{NULL} as sentinel. When
compiling only with GCC this is a valid sentinel, as @code{NULL} is defined
to @code{__null}. Although it is a null pointer constant not a null pointer,
-it is guaranteed to of the same size as a pointer. But this use is
+it is guaranteed to be of the same size as a pointer. But this use is
not portable across different compilers.
@item -Wno-non-template-friend @r{(C++ and Objective-C++ only)}
enumeration. @code{case} labels outside the enumeration range also
provoke warnings when this option is used.
+@item -Wsync-nand @r{(C and C++ only)}
+@opindex Wsync-nand
+@opindex Wno-sync-nand
+Warn when @code{__sync_fetch_and_nand} and @code{__sync_nand_and_fetch}
+built-in functions are used. These functions changed semantics in GCC 4.4.
+
@item -Wtrigraphs
@opindex Wtrigraphs
@opindex Wno-trigraphs
@option{-funsafe-loop-optimizations} warn if the compiler made
such assumptions.
-@item -Wno-pedantic-ms-format
+@item -Wno-pedantic-ms-format @r{(MinGW targets only)}
@opindex Wno-pedantic-ms-format
@opindex Wpedantic-ms-format
Disables the warnings about non-ISO @code{printf} / @code{scanf} format
@end group
@end smallexample
+@item -Wpacked-bitfield-compat
+@opindex Wpacked-bitfield-compat
+@opindex Wno-packed-bitfield-compat
+The 4.1, 4.2 and 4.3 series of GCC ignore the @code{packed} attribute
+on bit-fields of type @code{char}. This has been fixed in GCC 4.4 but
+the change can lead to differences in the structure layout. GCC
+informs you when the offset of such a field has changed in GCC 4.4.
+For example there is no longer a 4-bit padding between field @code{a}
+and @code{b} in this structure:
+
+@smallexample
+struct foo
+@{
+ char a:4;
+ char b:8;
+@} __attribute__ ((packed));
+@end smallexample
+
+This warning is enabled by default. Use
+@option{-Wno-packed-bitfield-compat} to disable this warning.
+
@item -Wpadded
@opindex Wpadded
@opindex Wno-padded
This option is implied by @option{-pedantic}, and can be disabled with
@option{-Wno-overlength-strings}.
-
-@item -Wdisallowed-function-list=@var{sym},@var{sym},@dots{}
-@opindex Wdisallowed-function-list
-
-If any of @var{sym} is called, GCC will issue a warning. This can be useful
-in enforcing coding conventions that ban calls to certain functions, for
-example, @code{alloca}, @code{malloc}, etc.
@end table
@node Debugging Options
@item -fno-merge-debug-strings
@opindex fmerge-debug-strings
@opindex fno-merge-debug-strings
-Direct the linker to merge together strings which are identical in
-different object files. This is not supported by all assemblers or
-linker. This decreases the size of the debug information in the
-output file at the cost of increasing link processing time. This is
-on by default.
+Direct the linker to not merge together strings in the debugging
+information which are identical in different object files. Merging is
+not supported by all assemblers or linkers. Merging decreases the size
+of the debug information in the output file at the cost of increasing
+link processing time. Merging is enabled by default.
@item -fdebug-prefix-map=@var{old}=@var{new}
@opindex fdebug-prefix-map
Debug dumps can be enabled with a @option{-fdump-rtl} switch or some
@option{-d} option @var{letters}. Here are the possible
-letters for use in @var{letters} and @var{pass}, and their meanings:
+letters for use in @var{pass} and @var{letters}, and their meanings:
@table @gcctabopt
-@item -dA
-@opindex dA
-Annotate the assembler output with miscellaneous debugging information.
+
+@item -fdump-rtl-alignments
+@opindex fdump-rtl-alignments
+Dump after branch alignments have been computed.
+
+@item -fdump-rtl-asmcons
+@opindex fdump-rtl-asmcons
+Dump after fixing rtl statements that have unsatisfied in/out constraints.
+
+@item -fdump-rtl-auto_inc_dec
+@opindex fdump-rtl-auto_inc_dec
+Dump after auto-inc-dec discovery. This pass is only run on
+architectures that have auto inc or auto dec instructions.
+
+@item -fdump-rtl-barriers
+@opindex fdump-rtl-barriers
+Dump after cleaning up the barrier instructions.
+
+@item -fdump-rtl-bbpart
+@opindex fdump-rtl-bbpart
+Dump after partitioning hot and cold basic blocks.
@item -fdump-rtl-bbro
@opindex fdump-rtl-bbro
-Dump after block reordering, to @file{@var{file}.148r.bbro}.
+Dump after block reordering.
+
+@item -fdump-rtl-btl1
+@itemx -fdump-rtl-btl2
+@opindex fdump-rtl-btl2
+@opindex fdump-rtl-btl2
+@option{-fdump-rtl-btl1} and @option{-fdump-rtl-btl2} enable dumping
+after the two branch
+target load optimization passes.
+
+@item -fdump-rtl-bypass
+@opindex fdump-rtl-bypass
+Dump after jump bypassing and control flow optimizations.
@item -fdump-rtl-combine
@opindex fdump-rtl-combine
-Dump after the RTL instruction combination pass, to the file
-@file{@var{file}.129r.combine}.
+Dump after the RTL instruction combination pass.
+
+@item -fdump-rtl-compgotos
+@opindex fdump-rtl-compgotos
+Dump after duplicating the computed gotos.
@item -fdump-rtl-ce1
@itemx -fdump-rtl-ce2
+@itemx -fdump-rtl-ce3
@opindex fdump-rtl-ce1
@opindex fdump-rtl-ce2
-@option{-fdump-rtl-ce1} enable dumping after the
-first if conversion, to the file @file{@var{file}.117r.ce1}.
-@option{-fdump-rtl-ce2} enable dumping after the second if
-conversion, to the file @file{@var{file}.130r.ce2}.
+@opindex fdump-rtl-ce3
+@option{-fdump-rtl-ce1}, @option{-fdump-rtl-ce2}, and
+@option{-fdump-rtl-ce3} enable dumping after the three
+if conversion passes.
+
+@itemx -fdump-rtl-cprop_hardreg
+@opindex fdump-rtl-cprop_hardreg
+Dump after hard register copy propagation.
+
+@itemx -fdump-rtl-csa
+@opindex fdump-rtl-csa
+Dump after combining stack adjustments.
+
+@item -fdump-rtl-cse1
+@itemx -fdump-rtl-cse2
+@opindex fdump-rtl-cse1
+@opindex fdump-rtl-cse2
+@option{-fdump-rtl-cse1} and @option{-fdump-rtl-cse2} enable dumping after
+the two common sub-expression elimination passes.
+
+@itemx -fdump-rtl-dce
+@opindex fdump-rtl-dce
+Dump after the standalone dead code elimination passes.
-@item -fdump-rtl-btl
@itemx -fdump-rtl-dbr
-@opindex fdump-rtl-btl
@opindex fdump-rtl-dbr
-@option{-fdump-rtl-btl} enable dumping after branch
-target load optimization, to @file{@var{file}.31.btl}.
-@option{-fdump-rtl-dbr} enable dumping after delayed branch
-scheduling, to @file{@var{file}.36.dbr}.
-
-@item -dD
-@opindex dD
-Dump all macro definitions, at the end of preprocessing, in addition to
-normal output.
+Dump after delayed branch scheduling.
-@item -fdump-rtl-ce3
-@opindex fdump-rtl-ce3
-Dump after the third if conversion, to @file{@var{file}.146r.ce3}.
-
-@item -fdump-rtl-cfg
-@itemx -fdump-rtl-life
-@opindex fdump-rtl-cfg
-@opindex fdump-rtl-life
-@option{-fdump-rtl-cfg} enable dumping after control
-and data flow analysis, to @file{@var{file}.116r.cfg}.
-@option{-fdump-rtl-cfg} enable dumping dump after life analysis,
-to @file{@var{file}.128r.life1} and @file{@var{file}.135r.life2}.
-
-@item -fdump-rtl-greg
-@opindex fdump-rtl-greg
-Dump after global register allocation, to @file{@var{file}.139r.greg}.
-
-@item -fdump-rtl-gcse
-@itemx -fdump-rtl-bypass
-@opindex fdump-rtl-gcse
-@opindex fdump-rtl-bypass
-@option{-fdump-rtl-gcse} enable dumping after GCSE, to
-@file{@var{file}.114r.gcse}. @option{-fdump-rtl-bypass}
-enable dumping after jump bypassing and control flow optimizations, to
-@file{@var{file}.115r.bypass}.
+@item -fdump-rtl-dce1
+@itemx -fdump-rtl-dce2
+@opindex fdump-rtl-dce1
+@opindex fdump-rtl-dce2
+@option{-fdump-rtl-dce1} and @option{-fdump-rtl-dce2} enable dumping after
+the two dead store elimination passes.
@item -fdump-rtl-eh
@opindex fdump-rtl-eh
-Dump after finalization of EH handling code, to @file{@var{file}.02.eh}.
+Dump after finalization of EH handling code.
-@item -fdump-rtl-sibling
-@opindex fdump-rtl-sibling
-Dump after sibling call optimizations, to @file{@var{file}.106r.sibling}.
+@item -fdump-rtl-eh_ranges
+@opindex fdump-rtl-eh_ranges
+Dump after conversion of EH handling range regions.
+
+@item -fdump-rtl-expand
+@opindex fdump-rtl-expand
+Dump after RTL generation.
+
+@item -fdump-rtl-fwprop1
+@itemx -fdump-rtl-fwprop2
+@opindex fdump-rtl-fwprop1
+@opindex fdump-rtl-fwprop2
+@option{-fdump-rtl-fwprop1} and @option{-fdump-rtl-fwprop2} enable
+dumping after the two forward propagation passes.
+
+@item -fdump-rtl-gcse1
+@itemx -fdump-rtl-gcse2
+@opindex fdump-rtl-gcse1
+@opindex fdump-rtl-gcse2
+@option{-fdump-rtl-gcse1} and @option{-fdump-rtl-gcse2} enable dumping
+after global common subexpression elimination.
+
+@item -fdump-rtl-init-regs
+@opindex fdump-rtl-init-regs
+Dump after the initialization of the registers.
+
+@item -fdump-rtl-initvals
+@opindex fdump-rtl-initvals
+Dump after the computation of the initial value sets.
+
+@itemx -fdump-rtl-into_cfglayout
+@opindex fdump-rtl-into_cfglayout
+Dump after converting to cfglayout mode.
+
+@item -fdump-rtl-ira
+@opindex fdump-rtl-ira
+Dump after iterated register allocation.
@item -fdump-rtl-jump
@opindex fdump-rtl-jump
-Dump after the first jump optimization, to @file{@var{file}.112r.jump}.
-
-@item -fdump-rtl-stack
-@opindex fdump-rtl-stack
-Dump after conversion from GCC's "flat register file" registers to the
-x87's stack-like registers, to @file{@var{file}.152r.stack}.
-
-@item -fdump-rtl-lreg
-@opindex fdump-rtl-lreg
-Dump after local register allocation, to @file{@var{file}.138r.lreg}.
+Dump after the second jump optimization.
@item -fdump-rtl-loop2
@opindex fdump-rtl-loop2
-@option{-fdump-rtl-loop2} enables dumping after the
-loop optimization pass, to @file{@var{file}.119r.loop2},
-@file{@var{file}.120r.loop2_init},
-@file{@var{file}.121r.loop2_invariant}, and
-@file{@var{file}.125r.loop2_done}.
-
-@item -fdump-rtl-sms
-@opindex fdump-rtl-sms
-Dump after modulo scheduling, to @file{@var{file}.136r.sms}.
+@option{-fdump-rtl-loop2} enables dumping after the rtl
+loop optimization passes.
@item -fdump-rtl-mach
@opindex fdump-rtl-mach
-Dump after performing the machine dependent reorganization pass, to
-@file{@var{file}.155r.mach} if that pass exists.
+Dump after performing the machine dependent reorganization pass, if that
+pass exists.
+
+@item -fdump-rtl-mode_sw
+@opindex fdump-rtl-mode_sw
+Dump after removing redundant mode switches.
@item -fdump-rtl-rnreg
@opindex fdump-rtl-rnreg
-Dump after register renumbering, to @file{@var{file}.147r.rnreg}.
+Dump after register renumbering.
-@item -fdump-rtl-regmove
-@opindex fdump-rtl-regmove
-Dump after the register move pass, to @file{@var{file}.132r.regmove}.
+@itemx -fdump-rtl-outof_cfglayout
+@opindex fdump-rtl-outof_cfglayout
+Dump after converting from cfglayout mode.
+
+@item -fdump-rtl-peephole2
+@opindex fdump-rtl-peephole2
+Dump after the peephole pass.
@item -fdump-rtl-postreload
@opindex fdump-rtl-postreload
-Dump after post-reload optimizations, to @file{@var{file}.24.postreload}.
-
-@item -fdump-rtl-expand
-@opindex fdump-rtl-expand
-Dump after RTL generation, to @file{@var{file}.104r.expand}.
+Dump after post-reload optimizations.
-@item -fdump-rtl-sched2
-@opindex fdump-rtl-sched2
-Dump after the second scheduling pass, to @file{@var{file}.149r.sched2}.
+@itemx -fdump-rtl-pro_and_epilogue
+@opindex fdump-rtl-pro_and_epilogue
+Dump after generating the function pro and epilogues.
-@item -fdump-rtl-cse
-@opindex fdump-rtl-cse
-Dump after CSE (including the jump optimization that sometimes follows
-CSE), to @file{@var{file}.113r.cse}.
+@item -fdump-rtl-regmove
+@opindex fdump-rtl-regmove
+Dump after the register move pass.
@item -fdump-rtl-sched1
+@itemx -fdump-rtl-sched2
@opindex fdump-rtl-sched1
-Dump after the first scheduling pass, to @file{@var{file}.136r.sched1}.
+@opindex fdump-rtl-sched2
+@option{-fdump-rtl-sched1} and @option{-fdump-rtl-sched2} enable dumping
+after the basic block scheduling passes.
-@item -fdump-rtl-cse2
-@opindex fdump-rtl-cse2
-Dump after the second CSE pass (including the jump optimization that
-sometimes follows CSE), to @file{@var{file}.127r.cse2}.
+@item -fdump-rtl-see
+@opindex fdump-rtl-see
+Dump after sign extension elimination.
-@item -fdump-rtl-tracer
-@opindex fdump-rtl-tracer
-Dump after running tracer, to @file{@var{file}.118r.tracer}.
+@item -fdump-rtl-seqabstr
+@opindex fdump-rtl-seqabstr
+Dump after common sequence discovery.
-@item -fdump-rtl-vpt
-@itemx -fdump-rtl-vartrack
-@opindex fdump-rtl-vpt
-@opindex fdump-rtl-vartrack
-@option{-fdump-rtl-vpt} enable dumping after the value
-profile transformations, to @file{@var{file}.10.vpt}.
-@option{-fdump-rtl-vartrack} enable dumping after variable tracking,
-to @file{@var{file}.154r.vartrack}.
+@item -fdump-rtl-shorten
+@opindex fdump-rtl-shorten
+Dump after shortening branches.
-@item -fdump-rtl-flow2
-@opindex fdump-rtl-flow2
-Dump after the second flow pass, to @file{@var{file}.142r.flow2}.
+@item -fdump-rtl-sibling
+@opindex fdump-rtl-sibling
+Dump after sibling call optimizations.
+
+@item -fdump-rtl-split1
+@itemx -fdump-rtl-split2
+@itemx -fdump-rtl-split3
+@itemx -fdump-rtl-split4
+@itemx -fdump-rtl-split5
+@opindex fdump-rtl-split1
+@opindex fdump-rtl-split2
+@opindex fdump-rtl-split3
+@opindex fdump-rtl-split4
+@opindex fdump-rtl-split5
+@option{-fdump-rtl-split1}, @option{-fdump-rtl-split2},
+@option{-fdump-rtl-split3}, @option{-fdump-rtl-split4} and
+@option{-fdump-rtl-split5} enable dumping after five rounds of
+instruction splitting.
-@item -fdump-rtl-peephole2
-@opindex fdump-rtl-peephole2
-Dump after the peephole pass, to @file{@var{file}.145r.peephole2}.
+@item -fdump-rtl-sms
+@opindex fdump-rtl-sms
+Dump after modulo scheduling. This pass is only run on some
+architectures.
+
+@item -fdump-rtl-stack
+@opindex fdump-rtl-stack
+Dump after conversion from GCC's "flat register file" registers to the
+x87's stack-like registers. This pass is only run on x86 variants.
+
+@item -fdump-rtl-subreg1
+@itemx -fdump-rtl-subreg2
+@opindex fdump-rtl-subreg1
+@opindex fdump-rtl-subreg2
+@option{-fdump-rtl-subreg1} and @option{-fdump-rtl-subreg2} enable dumping after
+the two subreg expansion passes.
+
+@item -fdump-rtl-unshare
+@opindex fdump-rtl-unshare
+Dump after all rtl has been unshared.
+
+@item -fdump-rtl-vartrack
+@opindex fdump-rtl-vartrack
+Dump after variable tracking.
+
+@item -fdump-rtl-vregs
+@opindex fdump-rtl-vregs
+Dump after converting virtual registers to hard registers.
@item -fdump-rtl-web
@opindex fdump-rtl-web
-Dump after live range splitting, to @file{@var{file}.126r.web}.
+Dump after live range splitting.
+
+@item -fdump-rtl-regclass
+@itemx -fdump-rtl-subregs_of_mode_init
+@itemx -fdump-rtl-subregs_of_mode_finish
+@itemx -fdump-rtl-dfinit
+@itemx -fdump-rtl-dfinish
+@opindex fdump-rtl-regclass
+@opindex fdump-rtl-subregs_of_mode_init
+@opindex fdump-rtl-subregs_of_mode_finish
+@opindex fdump-rtl-dfinit
+@opindex fdump-rtl-dfinish
+These dumps are defined but always produce empty files.
@item -fdump-rtl-all
@opindex fdump-rtl-all
Produce all the dumps listed above.
+@item -dA
+@opindex dA
+Annotate the assembler output with miscellaneous debugging information.
+
+@item -dD
+@opindex dD
+Dump all macro definitions, at the end of preprocessing, in addition to
+normal output.
+
@item -dH
@opindex dH
Produce a core dump whenever an error occurs.
dependence info.
@item -save-temps
+@itemx -save-temps=cwd
@opindex save-temps
Store the usual ``temporary'' intermediate files permanently; place them
in the current directory and name them based on the source file. Thus,
The corresponding intermediate file may be obtained by renaming the
source file before using @option{-save-temps}.
+If you invoke GCC in parallel, compiling several different source
+files that share a common base name in different subdirectories or the
+same source file compiled for multiple output destinations, it is
+likely that the different parallel compilers will interfere with each
+other, and overwrite the temporary files. For instance:
+
+@smallexample
+gcc -save-temps -o outdir1/foo.o indir1/foo.c&
+gcc -save-temps -o outdir2/foo.o indir2/foo.c&
+@end smallexample
+
+may result in @file{foo.i} and @file{foo.o} being written to
+simultaneously by both compilers.
+
+@item -save-temps=obj
+@opindex save-temps=obj
+Store the usual ``temporary'' intermediate files permanently. If the
+@option{-o} option is used, the temporary files are based on the
+object file. If the @option{-o} option is not used, the
+@option{-save-temps=obj} switch behaves like @option{-save-temps}.
+
+For example:
+
+@smallexample
+gcc -save-temps=obj -c foo.c
+gcc -save-temps=obj -c bar.c -o dir/xbar.o
+gcc -save-temps=obj foobar.c -o dir2/yfoobar
+@end smallexample
+
+would create @file{foo.i}, @file{foo.s}, @file{dir/xbar.i},
+@file{dir/xbar.s}, @file{dir2/yfoobar.i}, @file{dir2/yfoobar.s}, and
+@file{dir2/yfoobar.o}.
+
@item -time
@opindex time
Report the CPU time taken by each subprocess in the compilation
each of them.
Not all optimizations are controlled directly by a flag. Only
-optimizations that have a flag are listed.
+optimizations that have a flag are listed in this section.
+
+Depending on the target and how GCC was configured, a slightly different
+set of optimizations may be enabled at each @option{-O} level than
+those listed here. You can invoke GCC with @samp{-Q --help=optimizers}
+to find out the exact set of optimizations that are enabled at each level.
+@xref{Overall Options}, for examples.
@table @gcctabopt
@item -O
@item -O2
@opindex O2
Optimize even more. GCC performs nearly all supported optimizations
-that do not involve a space-speed tradeoff. The compiler does not
-perform loop unrolling or function inlining when you specify @option{-O2}.
+that do not involve a space-speed tradeoff.
As compared to @option{-O}, this option increases both compilation time
and the performance of the generated code.
This option implies @option{-fmerge-constants}. In addition to
@option{-fmerge-constants} this considers e.g.@: even constant initialized
arrays or initialized constant variables with integral or floating point
-types. Languages like C or C++ require each non-automatic variable to
-have distinct location, so using this option will result in non-conforming
+types. Languages like C or C++ require each variable, including multiple
+instances of the same variable in recursive calls, to have distinct locations,
+so using this option will result in non-conforming
behavior.
@item -fmodulo-sched
@item -fdelete-null-pointer-checks
@opindex fdelete-null-pointer-checks
-Use global dataflow analysis to identify and eliminate useless checks
-for null pointers. The compiler assumes that dereferencing a null
-pointer would have halted the program. If a pointer is checked after
-it has already been dereferenced, it cannot be null.
-
-In some environments, this assumption is not true, and programs can
-safely dereference null pointers. Use
-@option{-fno-delete-null-pointer-checks} to disable this optimization
+Assume that programs cannot safely dereference null pointers, and that
+no code or data element resides there. This enables simple constant
+folding optimizations at all optimization levels. In addition, other
+optimization passes in GCC use this flag to control global dataflow
+analyses that eliminate useless checks for null pointers; these assume
+that if a pointer is checked after it has already been dereferenced,
+it cannot be null.
+
+Note however that in some environments this assumption is not true.
+Use @option{-fno-delete-null-pointer-checks} to disable this optimization
for programs which depend on that behavior.
-Enabled at levels @option{-O2}, @option{-O3}, @option{-Os}.
+Some targets, especially embedded ones, disable this option at all levels.
+Otherwise it is enabled at all levels: @option{-O0}, @option{-O1},
+@option{-O2}, @option{-O3}, @option{-Os}. Passes that use the information
+are enabled independently at different optimization levels.
@item -fexpensive-optimizations
@opindex fexpensive-optimizations
Enabled at levels @option{-O2}, @option{-O3}, @option{-Os}.
-@item -fira
-@opindex fira
-Use the integrated register allocator (@acronym{IRA}) for register
-allocation. It is a default if @acronym{IRA} has been ported for the
-target.
-
@item -fira-algorithm=@var{algorithm}
-Use specified algorithm for the integrated register allocator. The
-@var{algorithm} argument should be one of @code{regional}, @code{CB},
-or @code{mixed}. The second algorithm specifies Chaitin-Briggs
-coloring, the first one specifies regional coloring based on
-Chaitin-Briggs coloring, and the third one which is the default
-specifies a mix of Chaitin-Briggs and regional algorithms where loops
-with small register pressure are ignored. The first algorithm can
-give best result for machines with small size and irregular register
-set, the second one is faster and generates decent code and the
-smallest size code, and the mixed algorithm usually give the best
-results in most cases and for most architectures.
+Use specified coloring algorithm for the integrated register
+allocator. The @var{algorithm} argument should be @code{priority} or
+@code{CB}. The first algorithm specifies Chow's priority coloring,
+the second one specifies Chaitin-Briggs coloring. The second
+algorithm can be unimplemented for some architectures. If it is
+implemented, it is the default because Chaitin-Briggs coloring as a
+rule generates a better code.
+
+@item -fira-region=@var{region}
+Use specified regions for the integrated register allocator. The
+@var{region} argument should be one of @code{all}, @code{mixed}, or
+@code{one}. The first value means using all loops as register
+allocation regions, the second value which is the default means using
+all loops except for loops with small register pressure as the
+regions, and third one means using all function as a single region.
+The first value can give best result for machines with small size and
+irregular register set, the third one results in faster and generates
+decent code and the smallest size code, and the default value usually
+give the best results in most cases and for most architectures.
@item -fira-coalesce
@opindex fira-coalesce
with its equivalent n-dimensional matrix, where n < m.
This reduces the level of indirection needed for accessing the elements
of the matrix. The second optimization is matrix transposing that
-attemps to change the order of the matrix's dimensions in order to
+attempts to change the order of the matrix's dimensions in order to
improve cache locality.
-Both optimizations need fwhole-program flag.
-Transposing is enabled only if profiling information is avaliable.
+Both optimizations need the @option{-fwhole-program} flag.
+Transposing is enabled only if profiling information is available.
@item -ftree-sink
contiguously by column, and the original loop iterates over rows,
potentially creating at each access a cache miss. This optimization
applies to all the languages supported by GCC and is not limited to
-Fortran.
+Fortran. To use this code transformation, GCC has to be configured
+with @option{--with-ppl} and @option{--with-cloog} to enable the
+Graphite loop transformation infrastructure.
@item -floop-strip-mine
Perform loop strip mining transformations on loops. Strip mining
ENDDO
@end smallexample
This optimization applies to all the languages supported by GCC and is
-not limited to Fortran.
+not limited to Fortran. To use this code transformation, GCC has to
+be configured with @option{--with-ppl} and @option{--with-cloog} to
+enable the Graphite loop transformation infrastructure.
@item -floop-block
Perform loop blocking transformations on loops. Blocking strip mines
which can be beneficial when @code{M} is larger than the caches,
because the innermost loop will iterate over a smaller amount of data
that can be kept in the caches. This optimization applies to all the
-languages supported by GCC and is not limited to Fortran.
+languages supported by GCC and is not limited to Fortran. To use this
+code transformation, GCC has to be configured with @option{--with-ppl}
+and @option{--with-cloog} to enable the Graphite loop transformation
+infrastructure.
@item -fcheck-data-deps
@opindex fcheck-data-deps
The following options are enabled: @code{-fprofile-arcs}, @code{-fprofile-values}, @code{-fvpt}.
If @var{path} is specified, GCC will look at the @var{path} to find
-the profile feeedback data files. See @option{-fprofile-dir}.
+the profile feedback data files. See @option{-fprofile-dir}.
@item -fprofile-use
@itemx -fprofile-use=@var{path}
point. Use @option{-ffloat-store} for such programs, after modifying
them to store all pertinent intermediate computations into variables.
+@item -fexcess-precision=@var{style}
+@opindex fexcess-precision
+This option allows further control over excess precision on machines
+where floating-point registers have more precision than the IEEE
+@code{float} and @code{double} types and the processor does not
+support operations rounding to those types. By default,
+@option{-fexcess-precision=fast} is in effect; this means that
+operations are carried out in the precision of the registers and that
+it is unpredictable when rounding to the types specified in the source
+code takes place. When compiling C, if
+@option{-fexcess-precision=standard} is specified then excess
+precision will follow the rules specified in ISO C99; in particular,
+both casts and assignments cause values to be rounded to their
+semantic types (whereas @option{-ffloat-store} only affects
+assignments). This option is enabled by default for C if a strict
+conformance option such as @option{-std=c99} is used.
+
+@opindex mfpmath
+@option{-fexcess-precision=standard} is not implemented for languages
+other than C, and has no effect if
+@option{-funsafe-math-optimizations} or @option{-ffast-math} is
+specified. On the x86, it also has no effect if @option{-mfpmath=sse}
+or @option{-mfpmath=sse+387} is specified; in the former case, IEEE
+semantics apply without excess precision, and in the latter, rounding
+is unpredictable.
+
@item -ffast-math
@opindex ffast-math
Sets @option{-fno-math-errno}, @option{-funsafe-math-optimizations},
using C99's @code{FENV_ACCESS} pragma. This command line option
will be used to specify the default state for @code{FENV_ACCESS}.
-@item -frtl-abstract-sequences
-@opindex frtl-abstract-sequences
-It is a size optimization method. This option is to find identical
-sequences of code, which can be turned into pseudo-procedures and
-then replace all occurrences with calls to the newly created
-subroutine. It is kind of an opposite of @option{-finline-functions}.
-This optimization runs at RTL level.
-
@item -fsignaling-nans
@opindex fsignaling-nans
Compile code assuming that IEEE signaling NaNs may generate user-visible
@item max-cse-insns
The maximum instructions CSE process before flushing. The default is 1000.
-@item max-aliased-vops
-
-Maximum number of virtual operands per function allowed to represent
-aliases before triggering the alias partitioning heuristic. Alias
-partitioning reduces compile times and memory consumption needed for
-aliasing at the expense of precision loss in alias information. The
-default value for this parameter is 100 for -O1, 500 for -O2 and 1000
-for -O3.
-
-Notice that if a function contains more memory statements than the
-value of this parameter, it is not really possible to achieve this
-reduction. In this case, the compiler will use the number of memory
-statements as the value for @option{max-aliased-vops}.
-
-@item avg-aliased-vops
-
-Average number of virtual operands per statement allowed to represent
-aliases before triggering the alias partitioning heuristic. This
-works in conjunction with @option{max-aliased-vops}. If a function
-contains more than @option{max-aliased-vops} virtual operators, then
-memory symbols will be grouped into memory partitions until either the
-total number of virtual operators is below @option{max-aliased-vops}
-or the average number of virtual operators per memory statement is
-below @option{avg-aliased-vops}. The default value for this parameter
-is 1 for -O1 and -O2, and 3 for -O3.
-
@item ggc-min-expand
GCC uses a garbage collector to manage its own memory allocation. This
the enhanced partial redundancy elimination optimization can run away,
consuming all of the memory available on the host machine. This
parameter sets a limit on the length of the sets that are computed,
-which prevents the runaway behaviour. Setting a value of 0 for
-this paramter will allow an unlimited set length.
+which prevents the runaway behavior. Setting a value of 0 for
+this parameter will allow an unlimited set length.
@item sccvn-max-scc-size
Maximum size of a strongly connected component (SCC) during SCCVN
@item ira-max-loops-num
IRA uses a regional register allocation by default. If a function
-contains loops more than number given by the parameter, non-regional
-register allocator will be used even when option
-@option{-fira-algorithm} is given. The default value of the parameter
-is 20.
+contains loops more than number given by the parameter, only at most
+given number of the most frequently executed loops will form regions
+for the regional register allocation. The default value of the
+parameter is 100.
+
+@item ira-max-conflict-table-size
+Although IRA uses a sophisticated algorithm of compression conflict
+table, the table can be still big for huge functions. If the conflict
+table for a function could be more than size in MB given by the
+parameter, the conflict table is not built and faster, simpler, and
+lower quality register allocation algorithm will be used. The
+algorithm do not use pseudo-register conflicts. The default value of
+the parameter is 2000.
+
+@item loop-invariant-max-bbs-in-loop
+Loop invariant motion can be very expensive, both in compile time and
+in amount of needed compile time memory, with very large loops. Loops
+with more basic blocks than this parameter won't have loop invariant
+motion optimization performed on them. The default value of the
+parameter is 1000 for -O1 and 10000 for -O2 and above.
@end table
@end table
supply system-specific linker options which GCC does not know how to
recognize.
-If you want to pass an option that takes an argument, you must use
+If you want to pass an option that takes a separate argument, you must use
@option{-Xlinker} twice, once for the option and once for the argument.
For example, to pass @option{-assert definitions}, you must write
@samp{-Xlinker -assert -Xlinker definitions}. It does not work to write
@option{-Xlinker "-assert definitions"}, because this passes the entire
string as a single argument, which is not what the linker expects.
+When using the GNU linker, it is usually more convenient to pass
+arguments to linker options using the @option{@var{option}=@var{value}}
+syntax than as separate arguments. For example, you can specify
+@samp{-Xlinker -Map=output.map} rather than
+@samp{-Xlinker -Map -Xlinker output.map}. Other linkers may not support
+this syntax for command-line options.
+
@item -Wl,@var{option}
@opindex Wl
Pass @var{option} as an option to the linker. If @var{option} contains
-commas, it is split into multiple options at the commas.
+commas, it is split into multiple options at the commas. You can use this
+syntax to pass an argument to the option.
+For example, @samp{-Wl,-Map,output.map} passes @samp{-Map output.map} to the
+linker. When using the GNU linker, you can also get the same effect with
+@samp{-Wl,-Map=output.map}.
@item -u @var{symbol}
@opindex u
arm-elf}, meaning to compile for an arm processor with elf binaries,
then you would specify @option{-b arm-elf} to run that cross compiler.
Because there are other options beginning with @option{-b}, the
-configuration must contain a hyphen.
+configuration must contain a hyphen, or @option{-b} alone should be one
+argument followed by the configuration in the next argument.
@item -V @var{version}
@opindex V
* Darwin Options::
* DEC Alpha Options::
* DEC Alpha/VMS Options::
+* FR30 Options::
* FRV Options::
* GNU/Linux Options::
* H8/300 Options::
* HPPA Options::
* i386 and x86-64 Options::
+* i386 and x86-64 Windows Options::
* IA-64 Options::
* M32C Options::
* M32R/D Options::
@samp{arm620}, @samp{arm7}, @samp{arm7m}, @samp{arm7d}, @samp{arm7dm},
@samp{arm7di}, @samp{arm7dmi}, @samp{arm70}, @samp{arm700},
@samp{arm700i}, @samp{arm710}, @samp{arm710c}, @samp{arm7100},
+@samp{arm720},
@samp{arm7500}, @samp{arm7500fe}, @samp{arm7tdmi}, @samp{arm7tdmi-s},
-@samp{arm8}, @samp{strongarm}, @samp{strongarm110}, @samp{strongarm1100},
+@samp{arm710t}, @samp{arm720t}, @samp{arm740t},
+@samp{strongarm}, @samp{strongarm110}, @samp{strongarm1100},
+@samp{strongarm1110},
@samp{arm8}, @samp{arm810}, @samp{arm9}, @samp{arm9e}, @samp{arm920},
@samp{arm920t}, @samp{arm922t}, @samp{arm946e-s}, @samp{arm966e-s},
@samp{arm968e-s}, @samp{arm926ej-s}, @samp{arm940t}, @samp{arm9tdmi},
@samp{arm10e}, @samp{arm1020e}, @samp{arm1022e},
@samp{arm1136j-s}, @samp{arm1136jf-s}, @samp{mpcore}, @samp{mpcorenovfp},
@samp{arm1156t2-s}, @samp{arm1176jz-s}, @samp{arm1176jzf-s},
-@samp{cortex-a8}, @samp{cortex-r4}, @samp{cortex-r4f}, @samp{cortex-m3},
+@samp{cortex-a8}, @samp{cortex-a9},
+@samp{cortex-r4}, @samp{cortex-r4f}, @samp{cortex-m3},
@samp{cortex-m1},
-@samp{xscale}, @samp{iwmmxt}, @samp{ep9312}.
+@samp{xscale}, @samp{iwmmxt}, @samp{iwmmxt2}, @samp{ep9312}.
@item -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{armv6}, @samp{armv6j},
+@samp{armv5}, @samp{armv5t}, @samp{armv5e}, @samp{armv5te},
+@samp{armv6}, @samp{armv6j},
@samp{armv6t2}, @samp{armv6z}, @samp{armv6zk}, @samp{armv6-m},
@samp{armv7}, @samp{armv7-a}, @samp{armv7-r}, @samp{armv7-m},
-@samp{iwmmxt}, @samp{ep9312}.
+@samp{iwmmxt}, @samp{iwmmxt2}, @samp{ep9312}.
@item -mfpu=@var{name}
@itemx -mfpe=@var{number}
the compiler generates code to handle function calls via function
pointers.
-@item -mnop-fun-dllimport
-@opindex mnop-fun-dllimport
-Disable support for the @code{dllimport} attribute.
-
@item -msingle-pic-base
@opindex msingle-pic-base
Treat the register used for PIC addressing as read-only, rather than
use the 32-bit ARM instruction set.
This option automatically enables either 16-bit Thumb-1 or
mixed 16/32-bit Thumb-2 instructions based on the @option{-mcpu=@var{name}}
-and @option{-march=@var{name}} options.
+and @option{-march=@var{name}} options. This option is not passed to the
+assembler. If you want to force assembler files to be interpreted as Thumb code,
+either add a @samp{.thumb} directive to the source or pass the @option{-mthumb}
+option directly to the assembler by prefixing it with @option{-Wa}.
@item -mtpcs-frame
@opindex mtpcs-frame
Only generate absolute relocations on word sized values (i.e. R_ARM_ABS32).
This is enabled by default on targets (uClinux, SymbianOS) where the runtime
loader imposes this restriction, and when @option{-fpic} or @option{-fPIC}
-is speficied.
+is specified.
@end table
Functions prologues/epilogues expanded as call to appropriate
subroutines. Code size will be smaller.
-@item -mno-tablejump
-@opindex mno-tablejump
-Do not generate tablejump insns which sometimes increase code size.
-
@item -mtiny-stack
@opindex mtiny-stack
Change only the low 8 bits of the stack pointer.
link scripts will be used to put the application into SDRAM.
Loader should initialize SDRAM before loading the application
into SDRAM. This option defines @code{__BFIN_SDRAM}.
+
+@item -micplb
+@opindex micplb
+Assume that ICPLBs are enabled at runtime. This has an effect on certain
+anomaly workarounds. For Linux targets, the default is to assume ICPLBs
+are enabled; for standalone applications the default is off.
@end table
@node CRIS Options
Schedules as an EV6 and supports the BWX, CIX, FIX, and MAX extensions.
@end table
+Native Linux/GNU toolchains also support the value @samp{native},
+which selects the best architecture option for the host processor.
+@option{-mcpu=native} has no effect if GCC does not recognize
+the processor.
+
@item -mtune=@var{cpu_type}
@opindex mtune
Set only the instruction scheduling parameters for machine type
@var{cpu_type}. The instruction set is not changed.
+Native Linux/GNU toolchains also support the value @samp{native},
+which selects the best architecture option for the host processor.
+@option{-mtune=native} has no effect if GCC does not recognize
+the processor.
+
@item -mmemory-latency=@var{time}
@opindex mmemory-latency
Sets the latency the scheduler should assume for typical memory
style condition (e.g.@: error) codes.
@end table
+@node FR30 Options
+@subsection FR30 Options
+@cindex FR30 Options
+
+These options are defined specifically for the FR30 port.
+
+@table @gcctabopt
+
+@item -msmall-model
+@opindex msmall-model
+Use the small address space model. This can produce smaller code, but
+it does assume that all symbolic values and addresses will fit into a
+20-bit range.
+
+@item -mno-lsim
+@opindex mno-lsim
+Assume that run-time support has been provided and so there is no need
+to include the simulator library (@file{libsim.a}) on the linker
+command line.
+
+@end table
+
@node FRV Options
@subsection FRV Options
@cindex FRV Options
@item core2
Intel Core2 CPU with 64-bit extensions, MMX, SSE, SSE2, SSE3 and SSSE3
instruction set support.
+@item atom
+Intel Atom CPU with 64-bit extensions, MMX, SSE, SSE2, SSE3 and SSSE3
+instruction set support.
@item k6
AMD K6 CPU with MMX instruction set support.
@item k6-2, k6-3
A deprecated synonym for @option{-mtune}.
@item -mfpmath=@var{unit}
-@opindex march
+@opindex mfpmath
Generate floating point arithmetics for selected unit @var{unit}. The choices
for @var{unit} are:
@item -mrecip
@opindex mrecip
This option will enable GCC to use RCPSS and RSQRTSS instructions (and their
-vectorized variants RCPPS and RSQRTPS) with an additional Newton-Rhapson step
+vectorized variants RCPPS and RSQRTPS) with an additional Newton-Raphson step
to increase precision instead of DIVSS and SQRTSS (and their vectorized
variants) for single precision floating point arguments. These instructions
are generated only when @option{-funsafe-math-optimizations} is enabled
@option{-funsafe-math-optimizations} have to be enabled. A SVML or ACML ABI
compatible library will have to be specified at link time.
+@item -mabi=@var{name}
+@opindex mabi
+Generate code for the specified calling convention. Permissible values
+are: @samp{sysv} for the ABI used on GNU/Linux and other systems and
+@samp{ms} for the Microsoft ABI. The default is to use the Microsoft
+ABI when targeting Windows. On all other systems, the default is the
+SYSV ABI. You can control this behavior for a specific function by
+using the function attribute @samp{ms_abi}/@samp{sysv_abi}.
+@xref{Function Attributes}.
+
@item -mpush-args
@itemx -mno-push-args
@opindex mpush-args
@item -mcmodel=medium
@opindex mcmodel=medium
Generate code for the medium model: The program is linked in the lower 2
-GB of the address space and symbols with small size as well. Symbols
+GB of the address space. Small symbols are also placed there. Symbols
with sizes larger than @option{-mlarge-data-threshold} are put into
large data or bss sections and can be located above 2GB. Programs can
be statically or dynamically linked.
@opindex m210
@opindex m340
Generate code for the 210 processor.
+
+@item -mno-lsim
+@opindex no-lsim
+Assume that run-time support has been provided and so omit the
+simulator library (@file{libsim.a)} from the linker command line.
+
+@item -mstack-increment=@var{size}
+@opindex mstack-increment
+Set the maximum amount for a single stack increment operation. Large
+values can increase the speed of programs which contain functions
+that need a large amount of stack space, but they can also trigger a
+segmentation fault if the stack is extended too much. The default
+value is 0x1000.
+
@end table
@node MIPS Options
immediately after starting an integer division.
@end itemize
+@item -mfix-r10000
+@itemx -mno-fix-r10000
+@opindex mfix-r10000
+@opindex mno-fix-r10000
+Work around certain R10000 errata:
+@itemize @minus
+@item
+@code{ll}/@code{sc} sequences may not behave atomically on revisions
+prior to 3.0. They may deadlock on revisions 2.6 and earlier.
+@end itemize
+
+This option can only be used if the target architecture supports
+branch-likely instructions. @option{-mfix-r10000} is the default when
+@option{-march=r10000} is used; @option{-mno-fix-r10000} is the default
+otherwise.
+
@item -mfix-vr4120
@itemx -mno-fix-vr4120
@opindex mfix-vr4120
warnings can be generated, for example, when compiling code which
performs byte-level memory operations on the MAC AE type. The MAC AE has
no hardware support for byte-level memory operations, so all byte
-load/stores must be synthesised from word load/store operations. This is
+load/stores must be synthesized from word load/store operations. This is
inefficient and a warning will be generated indicating to the programmer
that they should rewrite the code to avoid byte operations, or to target
an AE type which has the necessary hardware support. This option enables
stored, which means code that walks the stack frame across interrupts or
signals may get corrupted data.
+@item -mavoid-indexed-addresses
+@item -mno-avoid-indexed-addresses
+@opindex mavoid-indexed-addresses
+@opindex mno-avoid-indexed-addresses
+Generate code that tries to avoid (not avoid) the use of indexed load
+or store instructions. These instructions can incur a performance
+penalty on Power6 processors in certain situations, such as when
+stepping through large arrays that cross a 16M boundary. This option
+is enabled by default when targetting Power6 and disabled otherwise.
+
@item -mfused-madd
@itemx -mno-fused-madd
@opindex mfused-madd
compile code the same as @option{-msdata=eabi}, otherwise compile code the
same as @option{-msdata=sysv}.
-@item -msdata-data
-@opindex msdata-data
+@item -msdata=data
+@opindex msdata=data
On System V.4 and embedded PowerPC systems, put small global
data in the @samp{.sdata} section. Put small uninitialized global
data in the @samp{.sbss} section. Do not use register @code{r13}
In the future, we may cause GCC to ignore all longcall specifications
when the linker is known to generate glue.
+@item -mtls-markers
+@itemx -mno-tls-markers
+@opindex mtls-markers
+@opindex mno-tls-markers
+Mark (do not mark) calls to @code{__tls_get_addr} with a relocation
+specifying the function argument. The relocation allows ld to
+reliably associate function call with argument setup instructions for
+TLS optimization, which in turn allows gcc to better schedule the
+sequence.
+
@item -pthread
@opindex pthread
Adds support for multithreading with the @dfn{pthreads} library.
These are listed under @xref{i386 and x86-64 Options}.
+@node i386 and x86-64 Windows Options
+@subsection i386 and x86-64 Windows Options
+@cindex i386 and x86-64 Windows Options
+
+These additional options are available for Windows targets:
+
+@table @gcctabopt
+@item -mconsole
+@opindex mconsole
+This option is available for Cygwin and MinGW targets. It
+specifies that a console application is to be generated, by
+instructing the linker to set the PE header subsystem type
+required for console applications.
+This is the default behaviour for Cygwin and MinGW targets.
+
+@item -mcygwin
+@opindex mcygwin
+This option is available for Cygwin targets. It specifies that
+the Cygwin internal interface is to be used for predefined
+preprocessor macros, C runtime libraries and related linker
+paths and options. For Cygwin targets this is the default behaviour.
+This option is deprecated and will be removed in a future release.
+
+@item -mno-cygwin
+@opindex mno-cygwin
+This option is available for Cygwin targets. It specifies that
+the MinGW internal interface is to be used instead of Cygwin's, by
+setting MinGW-related predefined macros and linker paths and default
+library options.
+This option is deprecated and will be removed in a future release.
+
+@item -mdll
+@opindex mdll
+This option is available for Cygwin and MinGW targets. It
+specifies that a DLL - a dynamic link library - is to be
+generated, enabling the selection of the required runtime
+startup object and entry point.
+
+@item -mnop-fun-dllimport
+@opindex mnop-fun-dllimport
+This option is available for Cygwin and MinGW targets. It
+specifies that the dllimport attribute should be ignored.
+
+@item -mthread
+@opindex mthread
+This option is available for MinGW targets. It specifies
+that MinGW-specific thread support is to be used.
+
+@item -mwin32
+@opindex mwin32
+This option is available for Cygwin and MinGW targets. It
+specifies that the typical Windows pre-defined macros are to
+be set in the pre-processor, but does not influence the choice
+of runtime library/startup code.
+
+@item -mwindows
+@opindex mwindows
+This option is available for Cygwin and MinGW targets. It
+specifies that a GUI application is to be generated by
+instructing the linker to set the PE header subsystem type
+appropriately.
+@end table
+
+See also under @ref{i386 and x86-64 Options} for standard options.
+
@node Xstormy16 Options
@subsection Xstormy16 Options
@cindex Xstormy16 Options
@item -fno-common
@opindex fno-common
-In C, allocate even uninitialized global variables in the data section of the
-object file, rather than generating them as common blocks. This has the
-effect that if the same variable is declared (without @code{extern}) in
-two different compilations, you will get an error when you link them.
-The only reason this might be useful is if you wish to verify that the
-program will work on other systems which always work this way.
+In C code, controls the placement of uninitialized global variables.
+Unix C compilers have traditionally permitted multiple definitions of
+such variables in different compilation units by placing the variables
+in a common block.
+This is the behavior specified by @option{-fcommon}, and is the default
+for GCC on most targets.
+On the other hand, this behavior is not required by ISO C, and on some
+targets may carry a speed or code size penalty on variable references.
+The @option{-fno-common} option specifies that the compiler should place
+uninitialized global variables in the data section of the object file,
+rather than generating them as common blocks.
+This has the effect that if the same variable is declared
+(without @code{extern}) in two different compilations,
+you will get a multiple-definition error when you link them.
+In this case, you must compile with @option{-fcommon} instead.
+Compiling with @option{-fno-common} is useful on targets for which
+it provides better performance, or if you wish to verify that the
+program will work on other systems which always treat uninitialized
+variable declarations this way.
@item -fno-ident
@opindex fno-ident
behavior for the options. For instance, if you use @option{-g} to
generate the precompiled header but not when using it, you may or may
not get debugging information for routines in the precompiled header.
-
-@node Running Protoize
-@section Running Protoize
-
-The program @code{protoize} is an optional part of GCC@. You can use
-it to add prototypes to a program, thus converting the program to ISO
-C in one respect. The companion program @code{unprotoize} does the
-reverse: it removes argument types from any prototypes that are found.
-
-When you run these programs, you must specify a set of source files as
-command line arguments. The conversion programs start out by compiling
-these files to see what functions they define. The information gathered
-about a file @var{foo} is saved in a file named @file{@var{foo}.X}.
-
-After scanning comes actual conversion. The specified files are all
-eligible to be converted; any files they include (whether sources or
-just headers) are eligible as well.
-
-But not all the eligible files are converted. By default,
-@code{protoize} and @code{unprotoize} convert only source and header
-files in the current directory. You can specify additional directories
-whose files should be converted with the @option{-d @var{directory}}
-option. You can also specify particular files to exclude with the
-@option{-x @var{file}} option. A file is converted if it is eligible, its
-directory name matches one of the specified directory names, and its
-name within the directory has not been excluded.
-
-Basic conversion with @code{protoize} consists of rewriting most
-function definitions and function declarations to specify the types of
-the arguments. The only ones not rewritten are those for varargs
-functions.
-
-@code{protoize} optionally inserts prototype declarations at the
-beginning of the source file, to make them available for any calls that
-precede the function's definition. Or it can insert prototype
-declarations with block scope in the blocks where undeclared functions
-are called.
-
-Basic conversion with @code{unprotoize} consists of rewriting most
-function declarations to remove any argument types, and rewriting
-function definitions to the old-style pre-ISO form.
-
-Both conversion programs print a warning for any function declaration or
-definition that they can't convert. You can suppress these warnings
-with @option{-q}.
-
-The output from @code{protoize} or @code{unprotoize} replaces the
-original source file. The original file is renamed to a name ending
-with @samp{.save} (for DOS, the saved filename ends in @samp{.sav}
-without the original @samp{.c} suffix). If the @samp{.save} (@samp{.sav}
-for DOS) file already exists, then the source file is simply discarded.
-
-@code{protoize} and @code{unprotoize} both depend on GCC itself to
-scan the program and collect information about the functions it uses.
-So neither of these programs will work until GCC is installed.
-
-Here is a table of the options you can use with @code{protoize} and
-@code{unprotoize}. Each option works with both programs unless
-otherwise stated.
-
-@table @code
-@item -B @var{directory}
-Look for the file @file{SYSCALLS.c.X} in @var{directory}, instead of the
-usual directory (normally @file{/usr/local/lib}). This file contains
-prototype information about standard system functions. This option
-applies only to @code{protoize}.
-
-@item -c @var{compilation-options}
-Use @var{compilation-options} as the options when running @command{gcc} to
-produce the @samp{.X} files. The special option @option{-aux-info} is
-always passed in addition, to tell @command{gcc} to write a @samp{.X} file.
-
-Note that the compilation options must be given as a single argument to
-@code{protoize} or @code{unprotoize}. If you want to specify several
-@command{gcc} options, you must quote the entire set of compilation options
-to make them a single word in the shell.
-
-There are certain @command{gcc} arguments that you cannot use, because they
-would produce the wrong kind of output. These include @option{-g},
-@option{-O}, @option{-c}, @option{-S}, and @option{-o} If you include these in
-the @var{compilation-options}, they are ignored.
-
-@item -C
-Rename files to end in @samp{.C} (@samp{.cc} for DOS-based file
-systems) instead of @samp{.c}. This is convenient if you are converting
-a C program to C++. This option applies only to @code{protoize}.
-
-@item -g
-Add explicit global declarations. This means inserting explicit
-declarations at the beginning of each source file for each function
-that is called in the file and was not declared. These declarations
-precede the first function definition that contains a call to an
-undeclared function. This option applies only to @code{protoize}.
-
-@item -i @var{string}
-Indent old-style parameter declarations with the string @var{string}.
-This option applies only to @code{protoize}.
-
-@code{unprotoize} converts prototyped function definitions to old-style
-function definitions, where the arguments are declared between the
-argument list and the initial @samp{@{}. By default, @code{unprotoize}
-uses five spaces as the indentation. If you want to indent with just
-one space instead, use @option{-i " "}.
-
-@item -k
-Keep the @samp{.X} files. Normally, they are deleted after conversion
-is finished.
-
-@item -l
-Add explicit local declarations. @code{protoize} with @option{-l} inserts
-a prototype declaration for each function in each block which calls the
-function without any declaration. This option applies only to
-@code{protoize}.
-
-@item -n
-Make no real changes. This mode just prints information about the conversions
-that would have been done without @option{-n}.
-
-@item -N
-Make no @samp{.save} files. The original files are simply deleted.
-Use this option with caution.
-
-@item -p @var{program}
-Use the program @var{program} as the compiler. Normally, the name
-@file{gcc} is used.
-
-@item -q
-Work quietly. Most warnings are suppressed.
-
-@item -v
-Print the version number, just like @option{-v} for @command{gcc}.
-@end table
-
-If you need special compiler options to compile one of your program's
-source files, then you should generate that file's @samp{.X} file
-specially, by running @command{gcc} on that source file with the
-appropriate options and the option @option{-aux-info}. Then run
-@code{protoize} on the entire set of files. @code{protoize} will use
-the existing @samp{.X} file because it is newer than the source file.
-For example:
-
-@smallexample
-gcc -Dfoo=bar file1.c -aux-info file1.X
-protoize *.c
-@end smallexample
-
-@noindent
-You need to include the special files along with the rest in the
-@code{protoize} command, even though their @samp{.X} files already
-exist, because otherwise they won't get converted.
-
-@xref{Protoize Caveats}, for more information on how to use
-@code{protoize} successfully.
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