-@c Copyright (C) 1988,89,92-97,1998 Free Software Foundation, Inc.
+@c Copyright (C) 1988,89,92,93,94,95,96,97,1998 Free Software Foundation, Inc.
@c This is part of the GCC manual.
@c For copying conditions, see the file gcc.texi.
@xref{C++ Dialect Options,,Options Controlling C++ Dialect}.
@smallexample
-fall-virtual -fdollars-in-identifiers -felide-constructors
--fenum-int-equiv -fexternal-templates -ffor-scope -fno-for-scope
--fhandle-signatures -fmemoize-lookups -fname-mangling-version-@var{n}
--fno-default-inline -fno-gnu-keywords -fnonnull-objects -fguiding-decls
+-fenum-int-equiv -fexternal-templates -ffor-scope
+-fno-for-scope -fhandle-signatures -fmemoize-lookups
+-fname-mangling-version-@var{n} -fno-default-inline
+-fno-gnu-keywords -fnonnull-objects -fguiding-decls
-foperator-names -fstrict-prototype -fthis-is-variable
-ftemplate-depth-@var{n} -nostdinc++ -traditional +e@var{n}
@end smallexample
-Wcast-align -Wcast-qual -Wchar-subscript -Wcomment
-Wconversion -Werror -Wformat
-Wid-clash-@var{len} -Wimplicit -Wimplicit-int
--Wimplicit-function-declarations -Wimport -Winline
+-Wimplicit-function-declaration -Wimport
+-Werror-implicit-function-declaration -Winline
-Wlarger-than-@var{len} -Wmain -Wmissing-declarations
--Wmissing-prototypes -Wnested-externs
--Wno-import -Wold-style-cast -Woverloaded-virtual -Wparentheses
--Wpointer-arith -Wredundant-decls -Wreorder -Wreturn-type -Wshadow
--Wsign-compare -Wstrict-prototypes -Wswitch -Wsynth
--Wtemplate-debugging -Wtraditional -Wtrigraphs
+-Wmissing-prototypes -Wnested-externs -Wno-import
+-Wold-style-cast -Woverloaded-virtual -Wparentheses
+-Wpointer-arith -Wredundant-decls -Wreorder -Wreturn-type
+-Wshadow -Wsign-compare -Wstrict-prototypes -Wswitch
+-Wsynth -Wtemplate-debugging -Wtraditional -Wtrigraphs
-Wundef -Wuninitialized -Wunused -Wwrite-strings
-Wunknown-pragmas
@end smallexample
-fcaller-saves -fcse-follow-jumps -fcse-skip-blocks
-fdelayed-branch -fexpensive-optimizations
-ffast-math -ffloat-store -fforce-addr -fforce-mem
--ffunction-sections -finline-functions
+-ffunction-sections -fgcse -finline-functions
-fkeep-inline-functions -fno-default-inline
-fno-defer-pop -fno-function-cse
-fno-inline -fno-peephole -fomit-frame-pointer -fregmove
@smallexample
@emph{M680x0 Options}
-m68000 -m68020 -m68020-40 -m68020-60 -m68030 -m68040
--m68060 -mcpu32 -m5200 -m68881 -mbitfield -mc68000 -mc68020 -mfpa
--mnobitfield -mrtd -mshort -msoft-float -malign-int
+-m68060 -mcpu32 -m5200 -m68881 -mbitfield -mc68000 -mc68020
+-mfpa -mnobitfield -mrtd -mshort -msoft-float
+-malign-int
@emph{VAX Options}
-mg -mgnu -munix
-mstorem-bug -muser-registers
@emph{ARM Options}
--mapcs-frame -mapcs-26 -mapcs-32
--mlittle-endian -mbig-endian -mwords-little-endian
--mshort-load-bytes -mno-short-load-bytes
--msoft-float -mhard-float
--mbsd -mxopen -mno-symrename
+-mapcs-frame -mno-apcs-frame
+-mapcs-26 -mapcs-32
+-mapcs-stack-check -mno-apcs-stack-check
+-mapcs-float -mno-apcs-float
+-mapcs-reentrant -mno-apcs-reentrant
+-msched-prolog -mno-sched-prolog
+-mlittle-endian -mbig-endian -mwords-little-endian
+-mshort-load-bytes -mno-short-load-bytes -mshort-load-words -mno-short-load-words
+-msoft-float -mhard-float -mfpe
+-mthumb-interwork -mno-thumb-interwork
+-mcpu= -march= -mfpe=
+-mstructure-size-boundary=
+-mbsd -mxopen -mno-symrename
+
+@emph{Thumb Options}
+-mtpcs-frame -mno-tpcs-frame
+-mtpcs-leaf-frame -mno-tpcs-leaf-frame
+-mlittle-endian -mbig-endian
+-mthumb-interwork -mno-thumb-interwork
+-mstructure-size-boundary=
@emph{MN10300 Options}
-mmult-bug
-mpowerpc-gfxopt -mno-powerpc-gfxopt
-mnew-mnemonics -mno-new-mnemonics
-mfull-toc -mminimal-toc -mno-fop-in-toc -mno-sum-in-toc
--mxl-call -mno-xl-call -mthreads -mpe
+-maix64 -maix32 -mxl-call -mno-xl-call -mthreads -mpe
-msoft-float -mhard-float -mmultiple -mno-multiple
-mstring -mno-string -mupdate -mno-update
-mfused-madd -mno-fused-madd -mbit-align -mno-bit-align
-mabicalls -mcpu=@var{cpu type} -membedded-data
-membedded-pic -mfp32 -mfp64 -mgas -mgp32 -mgp64
-mgpopt -mhalf-pic -mhard-float -mint64 -mips1
--mips2 -mips3 -mlong64 -mlong-calls -mmemcpy
+-mips2 -mips3 -mips4 -mlong64 -mlong-calls -mmemcpy
-mmips-as -mmips-tfile -mno-abicalls
-mno-embedded-data -mno-embedded-pic
-mno-gpopt -mno-long-calls
-mrnames -msoft-float
-m4650 -msingle-float -mmad
-mstats -EL -EB -G @var{num} -nocpp
+-mabi=32 -mabi=n32 -mabi=64 -mabi=eabi
@emph{i386 Options}
-mcpu=@var{cpu type}
-malign-functions=@var{num}
@emph{HPPA Options}
--mbig-switch -mdisable-fpregs -mdisable-indexing -mfast-indirect-calls
--mgas -mjump-in-delay -mlong-load-store -mno-big-switch -mno-disable-fpregs
+-mbig-switch -mdisable-fpregs -mdisable-indexing
+-mfast-indirect-calls -mgas -mjump-in-delay
+-mlong-load-store -mno-big-switch -mno-disable-fpregs
-mno-disable-indexing -mno-fast-indirect-calls -mno-gas
--mno-jump-in-delay
--mno-long-load-store
--mno-portable-runtime -mno-soft-float -mno-space -mno-space-regs
--msoft-float
--mpa-risc-1-0 -mpa-risc-1-1 -mportable-runtime
+-mno-jump-in-delay -mno-long-load-store
+-mno-portable-runtime -mno-soft-float -mno-space
+-mno-space-regs -msoft-float -mpa-risc-1-0
+-mpa-risc-1-1 -mportable-runtime
-mschedule=@var{list} -mspace -mspace-regs
@emph{Intel 960 Options}
-mrelax -mh -ms -mint32 -malign-300
@emph{SH Options}
--m1 -m2 -m3 -m3e -mb -ml -mrelax
+-m1 -m2 -m3 -m3e -mb -ml -mdalign -mrelax
@emph{System V Options}
-Qy -Qn -YP,@var{paths} -Ym,@var{dir}
+@emph{ARC Options}
+-EB -EL
+-mmangle-cpu -mcpu=@var{cpu} -mtext=@var{text section}
+-mdata=@var{data section} -mrodata=@var{readonly data section}
+
@emph{V850 Options}
-mlong-calls -mno-long-calls -mep -mno-ep
-mprolog-function -mno-prolog-function -mspace
circumstances, you might want to compile programs from standard input,
or otherwise without a suffix that flags them as C++ programs.
@code{g++} is a program that calls GNU CC with the default language
-set to C++, and automatically specifies linking against the GNU class
-library libg++.
+set to C++, and automatically specifies linking against the C++
+library.
@cindex @code{g++ 1.@var{xx}}
@cindex @code{g++}, separate compiler
@cindex @code{g++} older version
ANSI C header files and you cannot use @samp{-traditional} on such
systems to compile files that include any system headers.
-The @samp{-traditional} option also enables the @samp{-traditional-cpp}
-option, which is described next.
+The @samp{-traditional} option also enables @samp{-traditional-cpp},
+which is described next.
@item -traditional-cpp
Attempt to support some aspects of traditional C preprocessors.
representable by a @samp{short int}. Users should not use this flag by
default; if you need to use it, the compiler will tell you so. If you
compile any of your code with this flag, you must compile @emph{all} of
-your code with this flag (including libg++, if you use it).
+your code with this flag (including the C++ library, if you use it).
This flag is not useful when compiling with -fvtable-thunks.
@samp{-fno-implicit-templates}. @xref{Template Instantiation}, for more
information.
+@item -fsquangle
+@itemx -fno-squangle
+@samp{-fsquangle} will enable a compressed form of name mangling for
+identifiers. In particular, it helps to shorten very long names by recognizing
+types and class names which occur more than once, replacing them with special
+short ID codes. This option also requires any C++ libraries being used to
+be compiled with this option as well. The compiler has this disabled (the
+equivalent of @samp{-fno-squangle}) by default.
+
@item -fthis-is-variable
Permit assignment to @code{this}. The incorporation of user-defined
free store management into C++ has made assignment to @samp{this} an
@item -nostdinc++
Do not search for header files in the standard directories specific to
C++, but do still search the other standard directories. (This option
-is used when building libg++.)
+is used when building the C++ library.)
@item -traditional
For C++ programs (in addition to the effects that apply to both C and
Check the code for syntax errors, but don't do anything beyond that.
@item -pedantic
-Issue all the warnings demanded by strict ANSI standard C; reject
-all programs that use forbidden extensions.
+Issue all the warnings demanded by strict ANSI C and ISO C++;
+reject all programs that use forbidden extensions.
-Valid ANSI standard C programs should compile properly with or without
+Valid ANSI C and ISO C++ programs should compile properly with or without
this option (though a rare few will require @samp{-ansi}). However,
-without this option, certain GNU extensions and traditional C features
-are supported as well. With this option, they are rejected.
+without this option, certain GNU extensions and traditional C and C++
+features are supported as well. With this option, they are rejected.
@samp{-pedantic} does not cause warning messages for use of the
alternate keywords whose names begin and end with @samp{__}. Pedantic
@item -Wimplicit-int
Warn when a declaration does not specify a type.
-@item -Wimplicit-function-declarations
-Warn whenever a function is used before being declared.
+@item -Wimplicit-function-declaration
+@itemx -Werror-implicit-function-declaration
+Give a warning (or error) whenever a function is used before being
+declared.
@item -Wimplicit
-Same as @samp{-Wimplicit-int} @samp{-Wimplicit-function-declaration}.
+Same as @samp{-Wimplicit-int} and @samp{-Wimplicit-function-}@*
+@samp{declaration}.
@item -Wmain
Warn if the type of @samp{main} is suspicious. @samp{main} should be a
@item
A comparison between signed and unsigned values could produce an
incorrect result when the signed value is converted to unsigned.
-(But do not warn if @samp{-Wno-sign-compare} is also specified.)
+(But don't warn if @samp{-Wno-sign-compare} is also specified.)
@item
An aggregate has a partly bracketed initializer.
@item d
Dump after delayed branch scheduling, to @file{@var{file}.dbr}.
@item D
+Dump all macro definitions, at the end of preprocessing, in addition to
+normal output.
+@item y
+Dump debugging information during parsing, to standard error.
+@item r
+Dump after RTL generation, to @file{@var{file}.rtl}.
+@item x
+Just generate RTL for a function instead of compiling it. Usually used
+with @samp{r}.
+@item j
+Dump after first jump optimization, to @file{@var{file}.jump}.
+@item s
+Dump after CSE (including the jump optimization that sometimes
+follows CSE), to @file{@var{file}.cse}.
+@item F
Dump after purging ADDRESSOF, to @file{@var{file}.addressof}.
@item f
Dump after flow analysis, to @file{@var{file}.flow}.
@item g
Dump after global register allocation, to @file{@var{file}.greg}.
+@item G
+Dump after GCSE, to @file{@var{file}.gcse}.
@item j
Dump after first jump optimization, to @file{@var{file}.jump}.
@item J
@item -frerun-loop-opt
Run the loop optimizer twice.
+@item -fgcse
+Perform a global common subexpression elimination pass.
+This pass also performs global constant and copy propagation.
+
@item -fexpensive-optimizations
Perform a number of minor optimizations that are relatively expensive.
guessing the path a branch might take.
@ifset INTERNALS
-With @samp{-fbranch-probabilities}, GNU CC puts a @samp{REG_EXEC_COUNT}
+With @samp{-fbranch-probabilities}, GCC puts a @samp{REG_EXEC_COUNT}
note on the first instruction of each basic block, and 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
Do not use the standard system libraries when linking.
Only the libraries you specify will be passed to the linker.
The standard startup files are used normally, unless @code{-nostartfiles}
-is used.
+is used. The compiler may generate calls to memcmp, memset, and memcpy
+for System V (and ANSI C) environments or to bcopy and bzero for
+BSD environments. These entries are usually resolved by entries in
+libc. These entry points should be supplied through some other
+mechanism when this option is specified.
@item -nostdlib
Do not use the standard system startup files or libraries when linking.
No startup files and only the libraries you specify will be passed to
-the linker.
+the linker. The compiler may generate calls to memcmp, memset, and memcpy
+for System V (and ANSI C) environments or to bcopy and bzero for
+BSD environments. These entries are usually resolved by entries in
+libc. These entry points should be supplied through some other
+mechanism when this option is specified.
@cindex @code{-lgcc}, use with @code{-nostdlib}
@cindex @code{-nostdlib} and unresolved references
* Convex Options::
* AMD29K Options::
* ARM Options::
+* Thumb Options::
* MN10300 Options::
* M32R/D Options::
* M88K Options::
* SH Options::
* System V Options::
* V850 Options::
+* ARC Options::
@end menu
@node M680x0 Options
option @samp{-mcpu=}@var{cpu_type} would.
The same values for @samp{-mcpu=}@var{cpu_type} are used for
-@samp{-mtune=}@var{cpu_type}, though the only useful values are those that
+@samp{-mtune=}@*@var{cpu_type}, though the only useful values are those that
select a particular cpu implementation: @samp{cypress}, @samp{supersparc},
@samp{f930}, @samp{f934}, @samp{tsc701}, @samp{ultrasparc}.
@kindex -mapcs-frame
Generate a stack frame that is compliant with the ARM Procedure Call
Standard for all functions, even if this is not strictly necessary for
-correct execution of the code.
+correct execution of the code. Specifying @samp{-fomit-frame-pointer}
+with this option will cause the stack frames not to be generated for
+leaf functions. The default is @samp{-mno-apcs-frame}.
+
+@item -mapcs
+@kindex -mapcs
+This is a synonym for @samp{-mapcs-frame}.
@item -mapcs-26
@kindex -mapcs-26
option. This option replaces the @samp{-m6} option of previous releases
of the compiler.
+@item -mapcs-stack-check
+@kindex -mapcs-stack-check
+@kindex -mno-apcs-stack-check
+Generate code to check the amount of stack space available upon entry to
+every function (that actually uses some stack space). If there is
+insufficient space available then either the function
+@samp{__rt_stkovf_split_small} or @samp{__rt_stkovf_split_big} will be
+called, depending upon the amount of stack space required. The run time
+system is required to provide these functions. The default is
+@samp{-mno-apcs-stack-check}, since this produces smaller code.
+
+@item -mapcs-float
+@kindex -mapcs-float
+@kindex -mno-apcs-float
+Pass floating point arguments using the float point registers. This is
+one of the variants of the APCS. This option is reccommended if the
+target hardware has a floating point unit or if a lot of floating point
+arithmetic is going to be performed by the code. The default is
+@samp{-mno-apcs-float}, since integer only code is slightly increased in
+size if @samp{-mapcs-float} is used.
+
+@item -mapcs-reentrant
+@kindex -mapcs-reentrant
+@kindex -mno-apcs-reentrant
+Generate reentrant, position independent code. This is the equivalent
+to specifying the @samp{-fpic} option. The default is
+@samp{-mno-apcs-reentrant}.
+
+@item -mthumb-interwork
+@kindex -mthumb-interwork
+@kindex -mno-thumb-interwork
+Generate code which supports calling between the ARM and THUMB
+instruction sets. Without this option the two instruction sets cannot
+be reliably used inside one program. The default is
+@samp{-mno-thumb-interwork}, since slightly larger code is generated
+when @samp{-mthumb-interwork} is specified.
+
+@item -mno-sched-prolog
+@kindex -mno-sched-prolog
+@kindex -msched-prolog
+Prevent the reordering of instructions in the function prolog, or the
+merging of those instruction with the instructions in the function's
+body. This means that all functions will start with a recognisable set
+of instructions (or in fact one of a chioce from a small set of
+different function prologues), and this information can be used to
+locate the start if functions inside an executable piece of code. The
+default is @samp{-msched-prolog}.
+
@item -mhard-float
Generate output containing floating point instructions. This is the
default.
option produces more efficient code, but the MMU is sometimes configured
to trap these instructions.
+@item -mshort-load-words
+@kindex -mshort-load-words
+This is a synonym for the @samp{-mno-short-load-bytes}.
+
+@item -mno-short-load-words
+@kindex -mno-short-load-words
+This is a synonym for the @samp{-mshort-load-bytes}.
+
@item -mbsd
@kindex -mbsd
This option only applies to RISC iX. Emulate the native BSD-mode
preparation for linking with the RISC iX C library; this option
suppresses this pass. The post-processor is never run when the
compiler is built for cross-compilation.
+
+@item -mcpu=<name>
+@kindex -mcpu=
+This specifies the name of the target ARM processor. GCC uses this name
+to determine what kind of instructions it can use when generating
+assembly code. Permissable names are: arm2, arm250, arm3, arm6, arm60,
+arm600, arm610, arm620, arm7, arm7m, arm7d, arm7dm, arm7di, arm7dmi,
+arm70, arm700, arm700i, arm710, arm710c, arm7100, arm7500, arm7500fe,
+arm7tdmi, arm8, strongarm, strongarm110
+
+@item -march=<name>
+@kindex -march=
+This specifies the name of the target ARM architecture. GCC uses this
+name to determine what kind of instructions it can use when generating
+assembly code. This option can be used in conjunction with or instead
+of the @samp{-mcpu=} option. Permissable names are: armv2, armv2a,
+armv3, armv3m, armv4, armv4t
+
+@item -mfpe=<number>
+@kindex -mfpe=
+This specifes the version of the floating point emulation available on
+the target. Permissable values are 2 and 3.
+
+@item -mstructure-size-boundary=<n>
+@kindex -mstructure-size-boundary
+The size of all structures and unions will be rounded up to a multiple
+of the number of bits set by this option. Permissable values are 8 and
+32. The default value varies for different toolchains. For the COFF
+targeted toolchain the default value is 8. Specifying the larger number
+can produced faster, more efficient code, but can also increase the size
+of the program. The two values are potentially incompatible. Code
+compiled with one value cannot necessarily expect to work with code or
+libraries compiled with the other value, if they exchange information
+using structures or unions. Programmers are encouraged to use the 32
+value as future versions of the toolchain may default to this value.
+
+@end table
+
+@node Thumb Options
+@subsection Thumb Options
+@cindex Thumb Options
+
+@table @code
+
+@item -mthumb-interwork
+@kindex -mthumb-interwork
+@kindex -mno-thumb-interwork
+Generate code which supports calling between the THUMB and ARM
+instruction sets. Without this option the two instruction sets cannot
+be reliably used inside one program. The default is
+@samp{-mno-thumb-interwork}, since slightly smaller code is generated
+with this option.
+
+@item -mtpcs-frame
+@kindex -mtpcs-frame
+@kindex -mno-tpcs-frame
+Generate a stack frame that is compliant with the Thumb Procedure Call
+Standard for all non-leaf functions. (A leaf function is one that does
+not call any other functions). The default is @samp{-mno-apcs-frame}.
+
+@item -mtpcs-leaf-frame
+@kindex -mtpcs-leaf-frame
+@kindex -mno-tpcs-leaf-frame
+Generate a stack frame that is compliant with the Thumb Procedure Call
+Standard for all leaf functions. (A leaf function is one that does
+not call any other functions). The default is @samp{-mno-apcs-leaf-frame}.
+
+@item -mlittle-endian
+@kindex -mlittle-endian
+Generate code for a processor running in little-endian mode. This is
+the default for all standard configurations.
+
+@item -mbig-endian
+@kindex -mbig-endian
+Generate code for a processor running in big-endian mode.
+
+@item -mstructure-size-boundary=<n>
+@kindex -mstructure-size-boundary
+The size of all structures and unions will be rounded up to a multiple
+of the number of bits set by this option. Permissable values are 8 and
+32. The default value varies for different toolchains. For the COFF
+targeted toolchain the default value is 8. Specifying the larger number
+can produced faster, more efficient code, but can also increase the size
+of the program. The two values are potentially incompatible. Code
+compiled with one value cannot necessarily expect to work with code or
+libraries compiled with the other value, if they exchange information
+using structures or unions. Programmers are encouraged to use the 32
+value as future versions of the toolchain may default to this value.
+
@end table
+
@node MN10300 Options
@subsection MN10300 Options
@cindex MN10300 options
@itemx -mno-powerpc-gpopt
@itemx -mpowerpc-gfxopt
@itemx -mno-powerpc-gfxopt
+@itemx -mpowerpc64
+@itemx -mno-powerpc64
@kindex -mpower
@kindex -mpower2
@kindex -mpowerpc
@kindex -mpowerpc-gpopt
@kindex -mpowerpc-gfxopt
+@kindex -mpowerpc64
GNU CC supports two related instruction set architectures for the
RS/6000 and PowerPC. The @dfn{POWER} instruction set are those
instructions supported by the @samp{rios} chip set used in the original
use the optional PowerPC architecture instructions in the Graphics
group, including floating-point select.
+The @samp{-mpowerpc64} option allows GNU CC to generate the additional
+64-bit instructions that are found in the full PowerPC64 architecture
+and to treat GPRs as 64-bit, doubleword quantities. GNU CC defaults to
+@samp{-mno-powerpc64}.
+
If you specify both @samp{-mno-power} and @samp{-mno-powerpc}, GNU CC
will use only the instructions in the common subset of both
architectures plus some special AIX common-mode calls, and will not use
GNU CC uses that mnemonic irrespective of which of these options is
specified.
-PowerPC assemblers support both the old and new mnemonics, as will later
-POWER assemblers. Current POWER assemblers only support the old
-mnemonics. Specify @samp{-mnew-mnemonics} if you have an assembler that
-supports them, otherwise specify @samp{-mold-mnemonics}.
-
-The default value of these options depends on how GNU CC was configured.
-Specifying @samp{-mcpu=@var{cpu_type}} sometimes overrides the value of
-these option. Unless you are building a cross-compiler, you should
-normally not specify either @samp{-mnew-mnemonics} or
+GNU CC defaults to the mnemonics appropriate for the architecture in
+use. Specifying @samp{-mcpu=@var{cpu_type}} sometimes overrides the
+value of these option. Unless you are building a cross-compiler, you
+should normally not specify either @samp{-mnew-mnemonics} or
@samp{-mold-mnemonics}, but should instead accept the default.
@item -mcpu=@var{cpu_type}
+@kindex -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{rs6000}, @samp{rios1},
@itemx -mno-fp-in-toc
@itemx -mno-sum-in-toc
@itemx -mminimal-toc
+@kindex -mminimal-toc
Modify generation of the TOC (Table Of Contents), which is created for
every executable file. The @samp{-mfull-toc} option is selected by
default. In that case, GNU CC will allocate at least one TOC entry for
uses extremely little TOC space. You may wish to use this option
only on files that contain less frequently executed code. @refill
+@item -maix64
+@itemx -maix32
+@kindex -maix64
+@kindex -maix32
+Enable AIX 64-bit ABI and calling convention: 64-bit pointers, 64-bit
+@code{long} type, and the infrastructure needed to support them.
+Specifying @samp{-maix64} implies @samp{-mpowerpc64} and
+@samp{-mpowerpc}, while @samp{-maix32} disables the 64-bit ABI and
+implies @samp{-mno-powerpc64}. GNU CC defaults to @samp{-maix32}.
+
@item -mxl-call
@itemx -mno-xl-call
+@kindex -mxl-call
On AIX, pass floating-point arguments to prototyped functions beyond the
register save area (RSA) on the stack in addition to argument FPRs. The
AIX calling convention was extended but not initially documented to
handle an obscure K&R C case of calling a function that takes the
address of its arguments with fewer arguments than declared. AIX XL
-compilers assume that floating point arguments which do not fit in the
-RSA are on the stack when they compile a subroutine without
+compilers access floating point arguments which do not fit in the
+RSA from the stack when a subroutine is compiled without
optimization. Because always storing floating-point arguments on the
stack is inefficient and rarely needed, this option is not enabled by
default and only is necessary when calling subroutines compiled by AIX
XL compilers without optimization.
@item -mthreads
+@kindex -mthreads
Support @dfn{AIX Threads}. Link an application written to use
@dfn{pthreads} with special libraries and startup code to enable the
application to run.
@item -mpe
+@kindex -mpe
Support @dfn{IBM RS/6000 SP} @dfn{Parallel Environment} (PE). Link an
application written to use message passing with special startup code to
enable the application to run. The system must have PE installed in the
@item -msoft-float
@itemx -mhard-float
+@kindex -msoft-float
Generate code that does not use (uses) the floating-point register set.
Software floating point emulation is provided if you use the
@samp{-msoft-float} option, and pass the option to GNU CC when linking.
@item -mstring
@itemx -mno-string
+@kindex -mstring
Generate code that uses (does not use) the load string instructions and the
store string word instructions to save multiple registers and do small block
moves. These instructions are generated by default on POWER systems, and not
@item -mupdate
@itemx -mno-update
+@kindex -mupdate
Generate code that uses (does not use) the load or store instructions
that update the base register to the address of the calculated memory
location. These instructions are generated by default. If you use
@item -mfused-madd
@itemx -mno-fused-madd
+@kindex -mfused-madd
Generate code that uses (does not use) the floating point multiply and
accumulate instructions. These instructions are generated by default if
hardware floating is used.
@item -mno-bit-align
@itemx -mbit-align
+@kindex -mbit-align
On System V.4 and embedded PowerPC systems do not (do) force structures
and unions that contain bit fields to be aligned to the base type of the
bit field.
@item -mno-strict-align
@itemx -mstrict-align
+@kindex -mstrict-align
On System V.4 and embedded PowerPC systems do not (do) assume that
unaligned memory references will be handled by the system.
@item -mrelocatable
@itemx -mno-relocatable
+@kindex -mrelocatable
On embedded PowerPC systems generate code that allows (does not allow)
the program to be relocated to a different address at runtime. If you
use @samp{-mrelocatable} on any module, all objects linked together must
@samp{r4000} is the default @var{cpu type} at this ISA level.
This option does not change the sizes of any of the C data types.
+@item -mips4
+Issue instructions from level 4 of the MIPS ISA. @samp{r8000} is the
+default @var{cpu type} at this ISA level.
+
@item -mfp32
Assume that 32 32-bit floating point registers are available. This is
the default.
Types long and pointer are 64 bits, and type int is 32 bits.
This works only if @samp{-mips3} is also specified.
+@itemx -mabi=32
+@itemx -mabi=n32
+@itemx -mabi=64
+@itemx -mabi=eabi
+Generate code for the indicated ABI.
+
@item -mmips-as
Generate code for the MIPS assembler, and invoke @file{mips-tfile} to
add normal debug information. This is the default for all
@item -membedded-pic
@itemx -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.
-This requires GNU as and GNU ld which do most of the work.
+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
@item -malign-loops=@var{num}
Align loops to a 2 raised to a @var{num} byte boundary. If
-@samp{-malign-loops} is not specified, the default is 2.
+@samp{-malign-loops} is not specified, the default is 2 unless
+gas 2.8 (or later) is being used in which case the default is
+to align the loop on a 16 byte boundary if it is less than 8
+bytes away.
@item -malign-jumps=@var{num}
Align instructions that are only jumped to to a 2 raised to a @var{num}
byte boundary. If @samp{-malign-jumps} is not specified, the default is
-2 if optimizing for a 386, and 4 if optimizing for a 486.
+2 if optimizing for a 386, and 4 if optimizing for a 486 unless
+gas 2.8 (or later) is being used in which case the default is
+to align the instruction on a 16 byte boundary if it is less
+than 8 bytes away.
@item -malign-functions=@var{num}
Align the start of functions to a 2 raised to @var{num} byte boundary.
@item -mschedule=@var{cpu type}
Schedule code according to the constraints for the machine type
@var{cpu type}. The choices for @var{cpu type} are @samp{700} for
-7@var{n}0 machines, @samp{7100} for 7@var{n}5 machines, and @samp{7100}
+7@var{n}0 machines, @samp{7100} for 7@var{n}5 machines, and @samp{7100LC}
for 7@var{n}2 machines. @samp{7100} is the default for @var{cpu type}.
Note the @samp{7100LC} scheduling information is incomplete and using
@item -ml
Compile code for the processor in little endian mode.
+@item -mdalign
+Align doubles at 64 bit boundaries. Note that this changes the calling
+conventions, and thus some functions from the standard C library will
+not work unless you recompile it first with -mdalign.
+
@item -mrelax
Shorten some address references at link time, when possible; uses the
linker option @samp{-relax}.
register, and call indirect through the pointer.
@item -mno-ep
-@item -mep
+@itemx -mep
Do not optimize (do optimize) basic blocks that use the same index
pointer 4 or more times to copy pointer into the @code{ep} register, and
use the shorter @code{sld} and @code{sst} instructions. The @samp{-mep}
table.
@end table
+@node ARC Options
+@subsection ARC Options
+@cindex ARC Options
+
+These options are defined for ARC implementations:
+
+@table @code
+@item -EL
+Compile code for little endian mode. This is the default.
+
+@item -EB
+Compile code for big endian mode.
+
+@item -mmangle-cpu
+Prepend the name of the cpu to all public symbol names.
+In multiple-processor systems, there are many ARC variants with different
+instruction and register set characteristics. This flag prevents code
+compiled for one cpu to be linked with code compiled for another.
+No facility exists for handling variants that are "almost identical".
+This is an all or nothing option.
+
+@item -mcpu=@var{cpu}
+Compile code for ARC variant @var{cpu}.
+Which variants are supported depend on the configuration.
+All variants support @samp{-mcpu=base}, this is the default.
+
+@item -mtext=@var{text section}
+@item -mdata=@var{data section}
+@item -mrodata=@var{readonly data section}
+Put functions, data, and readonly data in @var{text section},
+@var{data section}, and @var{readonly data section} respectively
+by default. This can be overridden with the @code{section} attribute.
+@xref{Variable Attributes}
+
+@end table
+
+
@node Code Gen Options
@section Options for Code Generation Conventions
@cindex code generation conventions
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