Here is a brief summary of how to invoke as. For details, see Command-Line Options.
as [-a[cdhlns][=file]] [--alternate] [-D]
[--debug-prefix-map old=new]
[--defsym sym=val] [-f] [-g] [--gstabs]
[--gstabs+] [--gdwarf-2] [--help] [-I dir] [-J]
[-K] [-L] [--listing-lhs-width=NUM]
[--listing-lhs-width2=NUM] [--listing-rhs-width=NUM]
[--listing-cont-lines=NUM] [--keep-locals] [-o
objfile] [-R] [--reduce-memory-overheads] [--statistics]
[-v] [-version] [--version] [-W] [--warn]
[--fatal-warnings] [-w] [-x] [-Z] [@FILE]
[--target-help] [target-options]
[--|files ...]
Target Alpha options:
[-mcpu]
[-mdebug | -no-mdebug]
[-relax] [-g] [-Gsize]
[-F] [-32addr]
Target ARC options:
[-marc[5|6|7|8]]
[-EB|-EL]
Target ARM options:
[-mcpu=processor[+extension...]]
[-march=architecture[+extension...]]
[-mfpu=floating-point-format]
[-mfloat-abi=abi]
[-meabi=ver]
[-mthumb]
[-EB|-EL]
[-mapcs-32|-mapcs-26|-mapcs-float|
-mapcs-reentrant]
[-mthumb-interwork] [-k]
Target CRIS options:
[--underscore | --no-underscore]
[--pic] [-N]
[--emulation=criself | --emulation=crisaout]
[--march=v0_v10 | --march=v10 | --march=v32 | --march=common_v10_v32]
Target D10V options:
[-O]
Target D30V options:
[-O|-n|-N]
Target i386 options:
[--32|--64] [-n]
[-march=CPU[+EXTENSION...]] [-mtune=CPU]
Target i960 options:
[-ACA|-ACA_A|-ACB|-ACC|-AKA|-AKB|
-AKC|-AMC]
[-b] [-no-relax]
Target IA-64 options:
[-mconstant-gp|-mauto-pic]
[-milp32|-milp64|-mlp64|-mp64]
[-mle|mbe]
[-mtune=itanium1|-mtune=itanium2]
[-munwind-check=warning|-munwind-check=error]
[-mhint.b=ok|-mhint.b=warning|-mhint.b=error]
[-x|-xexplicit] [-xauto] [-xdebug]
Target IP2K options:
[-mip2022|-mip2022ext]
Target M32C options:
[-m32c|-m16c]
Target M32R options:
[--m32rx|--[no-]warn-explicit-parallel-conflicts|
--W[n]p]
Target M680X0 options:
[-l] [-m68000|-m68010|-m68020|...]
Target M68HC11 options:
[-m68hc11|-m68hc12|-m68hcs12]
[-mshort|-mlong]
[-mshort-double|-mlong-double]
[--force-long-branches] [--short-branches]
[--strict-direct-mode] [--print-insn-syntax]
[--print-opcodes] [--generate-example]
Target MCORE options:
[-jsri2bsr] [-sifilter] [-relax]
[-mcpu=[210|340]]
Target MIPS options:
[-nocpp] [-EL] [-EB] [-O[optimization level]]
[-g[debug level]] [-G num] [-KPIC] [-call_shared]
[-non_shared] [-xgot [-mvxworks-pic]
[-mabi=ABI] [-32] [-n32] [-64] [-mfp32] [-mgp32]
[-march=CPU] [-mtune=CPU] [-mips1] [-mips2]
[-mips3] [-mips4] [-mips5] [-mips32] [-mips32r2]
[-mips64] [-mips64r2]
[-construct-floats] [-no-construct-floats]
[-trap] [-no-break] [-break] [-no-trap]
[-mfix7000] [-mno-fix7000]
[-mips16] [-no-mips16]
[-msmartmips] [-mno-smartmips]
[-mips3d] [-no-mips3d]
[-mdmx] [-no-mdmx]
[-mdsp] [-mno-dsp]
[-mdspr2] [-mno-dspr2]
[-mmt] [-mno-mt]
[-mdebug] [-no-mdebug]
[-mpdr] [-mno-pdr]
Target MMIX options:
[--fixed-special-register-names] [--globalize-symbols]
[--gnu-syntax] [--relax] [--no-predefined-symbols]
[--no-expand] [--no-merge-gregs] [-x]
[--linker-allocated-gregs]
Target PDP11 options:
[-mpic|-mno-pic] [-mall] [-mno-extensions]
[-mextension|-mno-extension]
[-mcpu] [-mmachine]
Target picoJava options:
[-mb|-me]
Target PowerPC options:
[-mpwrx|-mpwr2|-mpwr|-m601|-mppc|-mppc32|-m603|-m604|
-m403|-m405|-mppc64|-m620|-mppc64bridge|-mbooke|
-mbooke32|-mbooke64]
[-mcom|-many|-maltivec] [-memb]
[-mregnames|-mno-regnames]
[-mrelocatable|-mrelocatable-lib]
[-mlittle|-mlittle-endian|-mbig|-mbig-endian]
[-msolaris|-mno-solaris]
Target SPARC options:
[-Av6|-Av7|-Av8|-Asparclet|-Asparclite
-Av8plus|-Av8plusa|-Av9|-Av9a]
[-xarch=v8plus|-xarch=v8plusa] [-bump]
[-32|-64]
Target TIC54X options:
[-mcpu=54[123589]|-mcpu=54[56]lp] [-mfar-mode|-mf]
[-merrors-to-file <filename>|-me <filename>]
Target Z80 options:
[-z80] [-r800]
[ -ignore-undocumented-instructions] [-Wnud]
[ -ignore-unportable-instructions] [-Wnup]
[ -warn-undocumented-instructions] [-Wud]
[ -warn-unportable-instructions] [-Wup]
[ -forbid-undocumented-instructions] [-Fud]
[ -forbid-unportable-instructions] [-Fup]
Target Xtensa options:
[--[no-]text-section-literals] [--[no-]absolute-literals]
[--[no-]target-align] [--[no-]longcalls]
[--[no-]transform]
[--rename-section oldname=newname]
@fileOptions in file are separated by whitespace. A whitespace
character may be included in an option by surrounding the entire
option in either single or double quotes. Any character (including a
backslash) may be included by prefixing the character to be included
with a backslash. The file may itself contain additional
@file options; any such options will be processed recursively.
-a[cdhlmns]-ac-ad-ah-al-am-an-as=fileYou may combine these options; for example, use `-aln' for assembly
listing without forms processing. The `=file' option, if used, must be
the last one. By itself, `-a' defaults to `-ahls'.
--alternate.altmacro.
-D--debug-prefix-map old=new--defsym sym=value.set pseudo-op.
-f-g--gen-debug--gstabs--gstabs+--gdwarf-2--help--target-help-I dir.include directives.
-J-K-L--keep-locals--listing-lhs-width=number--listing-lhs-width2=number--listing-rhs-width=number--listing-cont-lines=number-o objfile-RSet the default size of GAS's hash tables to a prime number close to
number. Increasing this value can reduce the length of time it takes the
assembler to perform its tasks, at the expense of increasing the assembler's
memory requirements. Similarly reducing this value can reduce the memory
requirements at the expense of speed.
--reduce-memory-overheads--statistics--strip-local-absolute-v-version--version-W--no-warn--fatal-warnings--warn-w-x-Z-- | files ...The following options are available when as is configured for an ARC processor.
-marc[5|6|7|8]-EB | -ELThe following options are available when as is configured for the ARM processor family.
-mcpu=processor[+extension...]-march=architecture[+extension...]-mfpu=floating-point-format-mfloat-abi=abi-mthumb-mapcs-32 | -mapcs-26 | -mapcs-float | -mapcs-reentrant-EB | -EL-mthumb-interwork-kSee the info pages for documentation of the CRIS-specific options.
The following options are available when as is configured for a D10V processor.
-OThe following options are available when as is configured for a D30V processor.
-O-n-NThe following options are available when as is configured for the Intel 80960 processor.
-ACA | -ACA_A | -ACB | -ACC | -AKA | -AKB | -AKC | -AMC-b-no-relaxThe following options are available when as is configured for the Ubicom IP2K series.
-mip2022ext-mip2022The following options are available when as is configured for the Renesas M32C and M16C processors.
-m32c-m16cThe following options are available when as is configured for the Renesas M32R (formerly Mitsubishi M32R) series.
--m32rx--warn-explicit-parallel-conflicts or --Wp--no-warn-explicit-parallel-conflicts or --WnpThe following options are available when as is configured for the Motorola 68000 series.
-l-m68000 | -m68008 | -m68010 | -m68020 | -m68030| -m68040 | -m68060 | -m68302 | -m68331 | -m68332| -m68333 | -m68340 | -mcpu32 | -m5200-m68881 | -m68882 | -mno-68881 | -mno-68882-m68851 | -mno-68851For details about the PDP-11 machine dependent features options, see PDP-11-Options.
-mpic | -mno-pic-mall-mall-extensions-mno-extensions-mextension | -mno-extension-mcpu-mmachineThe following options are available when as is configured for a picoJava processor.
The following options are available when as is configured for the Motorola 68HC11 or 68HC12 series.
-m68hc11 | -m68hc12 | -m68hcs12-mshort-mlong-mshort-double-mlong-double--force-long-branches-S | --short-branches--strict-direct-mode--print-insn-syntax--print-opcodes--generate-exampleThe following options are available when as is configured for the SPARC architecture:
-Av6 | -Av7 | -Av8 | -Asparclet | -Asparclite-Av8plus | -Av8plusa | -Av9 | -Av9a`-Av8plus' and `-Av8plusa' select a 32 bit environment. `-Av9' and `-Av9a' select a 64 bit environment.
`-Av8plusa' and `-Av9a' enable the SPARC V9 instruction set with
UltraSPARC extensions.
-xarch=v8plus | -xarch=v8plusa-bumpThe following options are available when as is configured for the 'c54x architecture.
-mfar-mode-mcpu=CPU_VERSION-merrors-to-file FILENAMEThe following options are available when as is configured for a mips processor.
-G numgp register. It is only accepted for targets that
use ECOFF format, such as a DECstation running Ultrix. The default value is 8.
-EB-EL-mips1-mips2-mips3-mips4-mips5-mips32-mips32r2-mips64-mips64r2-march=CPU-mtune=cpu-mfix7000-mno-fix7000-mdebug-no-mdebug-mpdr-mno-pdr.pdr sections.
-mgp32-mfp32-mips16-no-mips16.set mips16 at the start of the assembly file. `-no-mips16'
turns off this option.
-msmartmips-mno-smartmips.set smartmips at the start of the assembly file.
`-mno-smartmips' turns off this option.
-mips3d-no-mips3d-mdmx-no-mdmx-mdsp-mno-dsp-mdspr2-mno-dspr2-mmt-mno-mt--construct-floats--no-construct-floats--emulation=nameThis option is currently supported only when the primary target as is configured for is a mips ELF or ECOFF target. Furthermore, the primary target or others specified with `--enable-targets=...' at configuration time must include support for the other format, if both are to be available. For example, the Irix 5 configuration includes support for both.
Eventually, this option will support more configurations, with more
fine-grained control over the assembler's behavior, and will be supported for
more processors.
-nocpp--trap--no-trap--break--no-break-nThe following options are available when as is configured for an MCore processor.
-jsri2bsr-nojsri2bsr-sifilter-nosifilter-relax-mcpu=[210|340]-EB-ELSee the info pages for documentation of the MMIX-specific options.
The following options are available when as is configured for an Xtensa processor.
--text-section-literals | --no-text-section-literalsL32R instructions; literals for
absolute mode L32R instructions are handled separately.
--absolute-literals | --no-absolute-literalsL32R instructions use absolute
or PC-relative addressing. The default is to assume absolute addressing
if the Xtensa processor includes the absolute L32R addressing
option. Otherwise, only the PC-relative L32R mode can be used.
--target-align | --no-target-align--longcalls | --no-longcalls--transform | --no-transform--rename-section oldname=newnameThe following options are available when as is configured for a Z80 family processor.
-z80-r800-ignore-undocumented-instructions-Wnud-ignore-unportable-instructions-Wnup-warn-undocumented-instructions-Wud-warn-unportable-instructions-Wup-forbid-undocumented-instructions-Fud-forbid-unportable-instructions-Fup