1AS(1) GNU Development Tools AS(1)
2
6 AS - the portable GNU assembler.
7
9 as [-a[cdghlns][=file]] [--alternate] [-D]
10 [--compress-debug-sections] [--nocompress-debug-sections]
11 [--debug-prefix-map old=new]
12 [--defsym sym=val] [-f] [-g] [--gstabs]
13 [--gstabs+] [--gdwarf-2] [--gdwarf-sections]
14 [--help] [-I dir] [-J]
15 [-K] [-L] [--listing-lhs-width=NUM]
16 [--listing-lhs-width2=NUM] [--listing-rhs-width=NUM]
17 [--listing-cont-lines=NUM] [--keep-locals] [-o
18 objfile] [-R] [--reduce-memory-overheads] [--statistics]
19 [-v] [-version] [--version] [-W] [--warn]
20 [--fatal-warnings] [-w] [-x] [-Z] [@FILE]
21 [--size-check=[error|warning]]
22 [--target-help] [target-options]
23 [--|files ...]
24 Target AArch64 options:
26 [-EB|-EL]
27 [-mabi=ABI]
28 Target Alpha options:
30 [-mcpu]
31 [-mdebug | -no-mdebug]
32 [-replace | -noreplace]
33 [-relax] [-g] [-Gsize]
34 [-F] [-32addr]
35 Target ARC options:
37 [-marc[5|6|7|8]]
38 [-EB|-EL]
39 Target ARM options:
41 [-mcpu=processor[+extension...]]
42 [-march=architecture[+extension...]]
43 [-mfpu=floating-point-format]
44 [-mfloat-abi=abi]
45 [-meabi=ver]
46 [-mthumb]
47 [-EB|-EL]
48 [-mapcs-32|-mapcs-26|-mapcs-float|
49 -mapcs-reentrant]
50 [-mthumb-interwork] [-k]
51 Target Blackfin options:
53 [-mcpu=processor[-sirevision]]
54 [-mfdpic]
55 [-mno-fdpic]
56 [-mnopic]
57 Target CRIS options:
59 [--underscore | --no-underscore]
60 [--pic] [-N]
61 [--emulation=criself | --emulation=crisaout]
62 [--march=v0_v10 | --march=v10 | --march=v32 |
63 --march=common_v10_v32]
64 Target D10V options:
66 [-O]
67 Target D30V options:
69 [-O|-n|-N]
70 Target EPIPHANY options:
72 [-mepiphany|-mepiphany16]
73 Target H8/300 options:
75 [-h-tick-hex]
76 Target i386 options:
78 [--32|--x32|--64] [-n]
79 [-march=CPU[+EXTENSION...]] [-mtune=CPU]
80 Target i960 options:
82 [-ACA|-ACA_A|-ACB|-ACC|-AKA|-AKB|
83 -AKC|-AMC]
84 [-b] [-no-relax]
85 Target IA-64 options:
87 [-mconstant-gp|-mauto-pic]
88 [-milp32|-milp64|-mlp64|-mp64]
89 [-mle|mbe]
90 [-mtune=itanium1|-mtune=itanium2]
91 [-munwind-check=warning|-munwind-check=error]
92 [-mhint.b=ok|-mhint.b=warning|-mhint.b=error]
93 [-x|-xexplicit] [-xauto] [-xdebug]
94 Target IP2K options:
96 [-mip2022|-mip2022ext]
97 Target M32C options:
99 [-m32c|-m16c] [-relax] [-h-tick-hex]
100 Target M32R options:
102 [--m32rx|--[no-]warn-explicit-parallel-conflicts|
103 --W[n]p]
104 Target M680X0 options:
106 [-l] [-m68000|-m68010|-m68020|...]
107 Target M68HC11 options:
109 [-m68hc11|-m68hc12|-m68hcs12|-mm9s12x|-mm9s12xg]
110 [-mshort|-mlong]
111 [-mshort-double|-mlong-double]
112 [--force-long-branches] [--short-branches]
113 [--strict-direct-mode] [--print-insn-syntax]
114 [--print-opcodes] [--generate-example]
115 Target MCORE options:
117 [-jsri2bsr] [-sifilter] [-relax]
118 [-mcpu=[210|340]]
119 Target Meta options:
121 [-mcpu=cpu] [-mfpu=cpu] [-mdsp=cpu] Target MICROBLAZE options:
122 Target MIPS options:
124 [-nocpp] [-EL] [-EB] [-O[optimization level]]
125 [-g[debug level]] [-G num] [-KPIC] [-call_shared]
126 [-non_shared] [-xgot [-mvxworks-pic]
127 [-mabi=ABI] [-32] [-n32] [-64] [-mfp32] [-mgp32]
128 [-march=CPU] [-mtune=CPU] [-mips1] [-mips2]
129 [-mips3] [-mips4] [-mips5] [-mips32] [-mips32r2]
130 [-mips64] [-mips64r2]
131 [-construct-floats] [-no-construct-floats]
132 [-mnan=encoding]
133 [-trap] [-no-break] [-break] [-no-trap]
134 [-mips16] [-no-mips16]
135 [-mmicromips] [-mno-micromips]
136 [-msmartmips] [-mno-smartmips]
137 [-mips3d] [-no-mips3d]
138 [-mdmx] [-no-mdmx]
139 [-mdsp] [-mno-dsp]
140 [-mdspr2] [-mno-dspr2]
141 [-mmt] [-mno-mt]
142 [-mmcu] [-mno-mcu]
143 [-minsn32] [-mno-insn32]
144 [-mfix7000] [-mno-fix7000]
145 [-mfix-vr4120] [-mno-fix-vr4120]
146 [-mfix-vr4130] [-mno-fix-vr4130]
147 [-mdebug] [-no-mdebug]
148 [-mpdr] [-mno-pdr]
149 Target MMIX options:
151 [--fixed-special-register-names] [--globalize-symbols]
152 [--gnu-syntax] [--relax] [--no-predefined-symbols]
153 [--no-expand] [--no-merge-gregs] [-x]
154 [--linker-allocated-gregs]
155 Target Nios II options:
157 [-relax-all] [-relax-section] [-no-relax]
158 [-EB] [-EL]
159 Target PDP11 options:
161 [-mpic|-mno-pic] [-mall] [-mno-extensions]
162 [-mextension|-mno-extension]
163 [-mcpu] [-mmachine]
164 Target picoJava options:
166 [-mb|-me]
167 Target PowerPC options:
169 [-a32|-a64]
170 [-mpwrx|-mpwr2|-mpwr|-m601|-mppc|-mppc32|-m603|-m604|-m403|-m405|
171 -m440|-m464|-m476|-m7400|-m7410|-m7450|-m7455|-m750cl|-mppc64|
172 -m620|-me500|-e500x2|-me500mc|-me500mc64|-me5500|-me6500|-mppc64bridge|
173 -mbooke|-mpower4|-mpwr4|-mpower5|-mpwr5|-mpwr5x|-mpower6|-mpwr6|
174 -mpower7|-mpwr7|-mpower8|-mpwr8|-ma2|-mcell|-mspe|-mtitan|-me300|-mcom]
175 [-many] [-maltivec|-mvsx|-mhtm|-mvle]
176 [-mregnames|-mno-regnames]
177 [-mrelocatable|-mrelocatable-lib|-K PIC] [-memb]
178 [-mlittle|-mlittle-endian|-le|-mbig|-mbig-endian|-be]
179 [-msolaris|-mno-solaris]
180 [-nops=count]
181 Target RX options:
183 [-mlittle-endian|-mbig-endian]
184 [-m32bit-doubles|-m64bit-doubles]
185 [-muse-conventional-section-names]
186 [-msmall-data-limit]
187 [-mpid]
188 [-mrelax]
189 [-mint-register=number]
190 [-mgcc-abi|-mrx-abi]
191 Target s390 options:
193 [-m31|-m64] [-mesa|-mzarch] [-march=CPU]
194 [-mregnames|-mno-regnames]
195 [-mwarn-areg-zero]
196 Target SCORE options:
198 [-EB][-EL][-FIXDD][-NWARN]
199 [-SCORE5][-SCORE5U][-SCORE7][-SCORE3]
200 [-march=score7][-march=score3]
201 [-USE_R1][-KPIC][-O0][-G num][-V]
202 Target SPARC options:
204 [-Av6|-Av7|-Av8|-Asparclet|-Asparclite
205 -Av8plus|-Av8plusa|-Av9|-Av9a]
206 [-xarch=v8plus|-xarch=v8plusa] [-bump]
207 [-32|-64]
208 Target TIC54X options:
210 [-mcpu=54[123589]|-mcpu=54[56]lp] [-mfar-mode|-mf]
211 [-merrors-to-file <filename>|-me <filename>]
212 Target TIC6X options:
214 [-march=arch] [-mbig-endian|-mlittle-endian]
215 [-mdsbt|-mno-dsbt] [-mpid=no|-mpid=near|-mpid=far]
216 [-mpic|-mno-pic]
217 Target TILE-Gx options:
219 [-m32|-m64][-EB][-EL]
220 Target Xtensa options:
222 [--[no-]text-section-literals] [--[no-]absolute-literals]
223 [--[no-]target-align] [--[no-]longcalls]
224 [--[no-]transform]
225 [--rename-section oldname=newname]
226 Target Z80 options:
228 [-z80] [-r800]
229 [ -ignore-undocumented-instructions] [-Wnud]
230 [ -ignore-unportable-instructions] [-Wnup]
231 [ -warn-undocumented-instructions] [-Wud]
232 [ -warn-unportable-instructions] [-Wup]
233 [ -forbid-undocumented-instructions] [-Fud]
234 [ -forbid-unportable-instructions] [-Fup]
235
237 GNU as is really a family of assemblers. If you use (or have used) the
238 GNU assembler on one architecture, you should find a fairly similar
239 environment when you use it on another architecture. Each version has
240 much in common with the others, including object file formats, most
241 assembler directives (often called pseudo-ops) and assembler syntax.
242 as is primarily intended to assemble the output of the GNU C compiler
244 "gcc" for use by the linker "ld". Nevertheless, we've tried to make as
245 assemble correctly everything that other assemblers for the same
246 machine would assemble. Any exceptions are documented explicitly.
247 This doesn't mean as always uses the same syntax as another assembler
248 for the same architecture; for example, we know of several incompatible
249 versions of 680x0 assembly language syntax.
250 Each time you run as it assembles exactly one source program. The
252 source program is made up of one or more files. (The standard input is
253 also a file.)
254 You give as a command line that has zero or more input file names. The
256 input files are read (from left file name to right). A command line
257 argument (in any position) that has no special meaning is taken to be
258 an input file name.
259 If you give as no file names it attempts to read one input file from
261 the as standard input, which is normally your terminal. You may have
262 to type ctl-D to tell as there is no more program to assemble.
263 Use -- if you need to explicitly name the standard input file in your
265 command line.
266 If the source is empty, as produces a small, empty object file.
268 as may write warnings and error messages to the standard error file
270 (usually your terminal). This should not happen when a compiler runs
271 as automatically. Warnings report an assumption made so that as could
272 keep assembling a flawed program; errors report a grave problem that
273 stops the assembly.
274 If you are invoking as via the GNU C compiler, you can use the -Wa
276 option to pass arguments through to the assembler. The assembler
277 arguments must be separated from each other (and the -Wa) by commas.
278 For example:
279 gcc -c -g -O -Wa,-alh,-L file.c
281 This passes two options to the assembler: -alh (emit a listing to
283 standard output with high-level and assembly source) and -L (retain
284 local symbols in the symbol table).
285 Usually you do not need to use this -Wa mechanism, since many compiler
287 command-line options are automatically passed to the assembler by the
288 compiler. (You can call the GNU compiler driver with the -v option to
289 see precisely what options it passes to each compilation pass,
290 including the assembler.)
291
293 @file
294 Read command-line options from file. The options read are inserted
295 in place of the original @file option. If file does not exist, or
296 cannot be read, then the option will be treated literally, and not
297 removed.
298 Options in file are separated by whitespace. A whitespace
300 character may be included in an option by surrounding the entire
301 option in either single or double quotes. Any character (including
302 a backslash) may be included by prefixing the character to be
303 included with a backslash. The file may itself contain additional
304 @file options; any such options will be processed recursively.
305 -a[cdghlmns]
307 Turn on listings, in any of a variety of ways:
308 -ac omit false conditionals
310 -ad omit debugging directives
312 -ag include general information, like as version and options passed
314 -ah include high-level source
316 -al include assembly
318 -am include macro expansions
320 -an omit forms processing
322 -as include symbols
324 =file
326 set the name of the listing file
327 You may combine these options; for example, use -aln for assembly
329 listing without forms processing. The =file option, if used, must
330 be the last one. By itself, -a defaults to -ahls.
331 --alternate
333 Begin in alternate macro mode.
334 --compress-debug-sections
336 Compress DWARF debug sections using zlib. The debug sections are
337 renamed to begin with .zdebug, and the resulting object file may
338 not be compatible with older linkers and object file utilities.
339 --nocompress-debug-sections
341 Do not compress DWARF debug sections. This is the default.
342 -D Ignored. This option is accepted for script compatibility with
344 calls to other assemblers.
345 --debug-prefix-map old=new
347 When assembling files in directory old, record debugging
348 information describing them as in new instead.
349 --defsym sym=value
351 Define the symbol sym to be value before assembling the input file.
352 value must be an integer constant. As in C, a leading 0x indicates
353 a hexadecimal value, and a leading 0 indicates an octal value. The
354 value of the symbol can be overridden inside a source file via the
355 use of a ".set" pseudo-op.
356 -f "fast"---skip whitespace and comment preprocessing (assume source
358 is compiler output).
359 -g
361 --gen-debug
362 Generate debugging information for each assembler source line using
363 whichever debug format is preferred by the target. This currently
364 means either STABS, ECOFF or DWARF2.
365 --gstabs
367 Generate stabs debugging information for each assembler line. This
368 may help debugging assembler code, if the debugger can handle it.
369 --gstabs+
371 Generate stabs debugging information for each assembler line, with
372 GNU extensions that probably only gdb can handle, and that could
373 make other debuggers crash or refuse to read your program. This
374 may help debugging assembler code. Currently the only GNU
375 extension is the location of the current working directory at
376 assembling time.
377 --gdwarf-2
379 Generate DWARF2 debugging information for each assembler line.
380 This may help debugging assembler code, if the debugger can handle
381 it. Note---this option is only supported by some targets, not all
382 of them.
383 --gdwarf-sections
385 Instead of creating a .debug_line section, create a series of
386 .debug_line.foo sections where foo is the name of the corresponding
387 code section. For example a code section called .text.func will
388 have its dwarf line number information placed into a section called
389 .debug_line.text.func. If the code section is just called .text
390 then debug line section will still be called just .debug_line
391 without any suffix.
392 --size-check=error
394 --size-check=warning
395 Issue an error or warning for invalid ELF .size directive.
396 --help
398 Print a summary of the command line options and exit.
399 --target-help
401 Print a summary of all target specific options and exit.
402 -I dir
404 Add directory dir to the search list for ".include" directives.
405 -J Don't warn about signed overflow.
407 -K Issue warnings when difference tables altered for long
409 displacements.
410 -L
412 --keep-locals
413 Keep (in the symbol table) local symbols. These symbols start with
414 system-specific local label prefixes, typically .L for ELF systems
415 or L for traditional a.out systems.
416 --listing-lhs-width=number
418 Set the maximum width, in words, of the output data column for an
419 assembler listing to number.
420 --listing-lhs-width2=number
422 Set the maximum width, in words, of the output data column for
423 continuation lines in an assembler listing to number.
424 --listing-rhs-width=number
426 Set the maximum width of an input source line, as displayed in a
427 listing, to number bytes.
428 --listing-cont-lines=number
430 Set the maximum number of lines printed in a listing for a single
431 line of input to number + 1.
432 -o objfile
434 Name the object-file output from as objfile.
435 -R Fold the data section into the text section.
437 Set the default size of GAS's hash tables to a prime number close
439 to number. Increasing this value can reduce the length of time it
440 takes the assembler to perform its tasks, at the expense of
441 increasing the assembler's memory requirements. Similarly reducing
442 this value can reduce the memory requirements at the expense of
443 speed.
444 --reduce-memory-overheads
446 This option reduces GAS's memory requirements, at the expense of
447 making the assembly processes slower. Currently this switch is a
448 synonym for --hash-size=4051, but in the future it may have other
449 effects as well.
450 --statistics
452 Print the maximum space (in bytes) and total time (in seconds) used
453 by assembly.
454 --strip-local-absolute
456 Remove local absolute symbols from the outgoing symbol table.
457 -v
459 -version
460 Print the as version.
461 --version
463 Print the as version and exit.
464 -W
466 --no-warn
467 Suppress warning messages.
468 --fatal-warnings
470 Treat warnings as errors.
471 --warn
473 Don't suppress warning messages or treat them as errors.
474 -w Ignored.
476 -x Ignored.
478 -Z Generate an object file even after errors.
480 -- | files ...
482 Standard input, or source files to assemble.
483 The following options are available when as is configured for the
485 64-bit mode of the ARM Architecture (AArch64).
486 -EB This option specifies that the output generated by the assembler
488 should be marked as being encoded for a big-endian processor.
489 -EL This option specifies that the output generated by the assembler
491 should be marked as being encoded for a little-endian processor.
492 -mabi=abi
494 Specify which ABI the source code uses. The recognized arguments
495 are: "ilp32" and "lp64", which decides the generated object file in
496 ELF32 and ELF64 format respectively. The default is "lp64".
497 The following options are available when as is configured for an Alpha
499 processor.
500 -mcpu
502 This option specifies the target processor. If an attempt is made
503 to assemble an instruction which will not execute on the target
504 processor, the assembler may either expand the instruction as a
505 macro or issue an error message. This option is equivalent to the
506 ".arch" directive.
507 The following processor names are recognized: 21064, "21064a",
509 21066, 21068, 21164, "21164a", "21164pc", 21264, "21264a",
510 "21264b", "ev4", "ev5", "lca45", "ev5", "ev56", "pca56", "ev6",
511 "ev67", "ev68". The special name "all" may be used to allow the
512 assembler to accept instructions valid for any Alpha processor.
513 In order to support existing practice in OSF/1 with respect to
515 ".arch", and existing practice within MILO (the Linux ARC
516 bootloader), the numbered processor names (e.g. 21064) enable the
517 processor-specific PALcode instructions, while the "electro-vlasic"
518 names (e.g. "ev4") do not.
519 -mdebug
521 -no-mdebug
522 Enables or disables the generation of ".mdebug" encapsulation for
523 stabs directives and procedure descriptors. The default is to
524 automatically enable ".mdebug" when the first stabs directive is
525 seen.
526 -relax
528 This option forces all relocations to be put into the object file,
529 instead of saving space and resolving some relocations at assembly
530 time. Note that this option does not propagate all symbol
531 arithmetic into the object file, because not all symbol arithmetic
532 can be represented. However, the option can still be useful in
533 specific applications.
534 -replace
536 -noreplace
537 Enables or disables the optimization of procedure calls, both at
538 assemblage and at link time. These options are only available for
539 VMS targets and "-replace" is the default. See section 1.4.1 of
540 the OpenVMS Linker Utility Manual.
541 -g This option is used when the compiler generates debug information.
543 When gcc is using mips-tfile to generate debug information for
544 ECOFF, local labels must be passed through to the object file.
545 Otherwise this option has no effect.
546 -Gsize
548 A local common symbol larger than size is placed in ".bss", while
549 smaller symbols are placed in ".sbss".
550 -F
552 -32addr
553 These options are ignored for backward compatibility.
554 The following options are available when as is configured for an ARC
556 processor.
557 -marc[5|6|7|8]
559 This option selects the core processor variant.
560 -EB | -EL
562 Select either big-endian (-EB) or little-endian (-EL) output.
563 The following options are available when as is configured for the ARM
565 processor family.
566 -mcpu=processor[+extension...]
568 Specify which ARM processor variant is the target.
569 -march=architecture[+extension...]
571 Specify which ARM architecture variant is used by the target.
572 -mfpu=floating-point-format
574 Select which Floating Point architecture is the target.
575 -mfloat-abi=abi
577 Select which floating point ABI is in use.
578 -mthumb
580 Enable Thumb only instruction decoding.
581 -mapcs-32 | -mapcs-26 | -mapcs-float | -mapcs-reentrant
583 Select which procedure calling convention is in use.
584 -EB | -EL
586 Select either big-endian (-EB) or little-endian (-EL) output.
587 -mthumb-interwork
589 Specify that the code has been generated with interworking between
590 Thumb and ARM code in mind.
591 -k Specify that PIC code has been generated.
593 The following options are available when as is configured for the
595 Blackfin processor family.
596 -mcpu=processor[-sirevision]
598 This option specifies the target processor. The optional
599 sirevision is not used in assembler. It's here such that GCC can
600 easily pass down its "-mcpu=" option. The assembler will issue an
601 error message if an attempt is made to assemble an instruction
602 which will not execute on the target processor. The following
603 processor names are recognized: "bf504", "bf506", "bf512", "bf514",
604 "bf516", "bf518", "bf522", "bf523", "bf524", "bf525", "bf526",
605 "bf527", "bf531", "bf532", "bf533", "bf534", "bf535" (not
606 implemented yet), "bf536", "bf537", "bf538", "bf539", "bf542",
607 "bf542m", "bf544", "bf544m", "bf547", "bf547m", "bf548", "bf548m",
608 "bf549", "bf549m", "bf561", and "bf592".
609 -mfdpic
611 Assemble for the FDPIC ABI.
612 -mno-fdpic
614 -mnopic
615 Disable -mfdpic.
616 See the info pages for documentation of the CRIS-specific options.
618 The following options are available when as is configured for a D10V
620 processor.
621 -O Optimize output by parallelizing instructions.
623 The following options are available when as is configured for a D30V
625 processor.
626 -O Optimize output by parallelizing instructions.
628 -n Warn when nops are generated.
630 -N Warn when a nop after a 32-bit multiply instruction is generated.
632 The following options are available when as is configured for an
634 Epiphany processor.
635 -mepiphany
637 Specifies that the both 32 and 16 bit instructions are allowed.
638 This is the default behavior.
639 -mepiphany16
641 Restricts the permitted instructions to just the 16 bit set.
642 The following options are available when as is configured for an H8/300
644 processor. @chapter H8/300 Dependent Features
645 Options
647 The Renesas H8/300 version of "as" has one machine-dependent option:
648 -h-tick-hex
650 Support H'00 style hex constants in addition to 0x00 style.
651 The following options are available when as is configured for an i386
653 processor.
654 --32 | --x32 | --64
656 Select the word size, either 32 bits or 64 bits. --32 implies
657 Intel i386 architecture, while --x32 and --64 imply AMD x86-64
658 architecture with 32-bit or 64-bit word-size respectively.
659 These options are only available with the ELF object file format,
661 and require that the necessary BFD support has been included (on a
662 32-bit platform you have to add --enable-64-bit-bfd to configure
663 enable 64-bit usage and use x86-64 as target platform).
664 -n By default, x86 GAS replaces multiple nop instructions used for
666 alignment within code sections with multi-byte nop instructions
667 such as leal 0(%esi,1),%esi. This switch disables the
668 optimization.
669 --divide
671 On SVR4-derived platforms, the character / is treated as a comment
672 character, which means that it cannot be used in expressions. The
673 --divide option turns / into a normal character. This does not
674 disable / at the beginning of a line starting a comment, or affect
675 using # for starting a comment.
676 -march=CPU[+EXTENSION...]
678 This option specifies the target processor. The assembler will
679 issue an error message if an attempt is made to assemble an
680 instruction which will not execute on the target processor. The
681 following processor names are recognized: "i8086", "i186", "i286",
682 "i386", "i486", "i586", "i686", "pentium", "pentiumpro",
683 "pentiumii", "pentiumiii", "pentium4", "prescott", "nocona",
684 "core", "core2", "corei7", "l1om", "k1om", "k6", "k6_2", "athlon",
685 "opteron", "k8", "amdfam10", "bdver1", "bdver2", "bdver3",
686 "btver1", "btver2", "generic32" and "generic64".
687 In addition to the basic instruction set, the assembler can be told
689 to accept various extension mnemonics. For example,
690 "-march=i686+sse4+vmx" extends i686 with sse4 and vmx. The
691 following extensions are currently supported: 8087, 287, 387,
692 "no87", "mmx", "nommx", "sse", "sse2", "sse3", "ssse3", "sse4.1",
693 "sse4.2", "sse4", "nosse", "avx", "avx2", "adx", "rdseed",
694 "prfchw", "smap", "mpx", "sha", "avx512f", "avx512cd", "avx512er",
695 "avx512pf", "noavx", "vmx", "vmfunc", "smx", "xsave", "xsaveopt",
696 "aes", "pclmul", "fsgsbase", "rdrnd", "f16c", "bmi2", "fma",
697 "movbe", "ept", "lzcnt", "hle", "rtm", "invpcid", "clflush", "lwp",
698 "fma4", "xop", "cx16", "syscall", "rdtscp", "3dnow", "3dnowa",
699 "sse4a", "sse5", "svme", "abm" and "padlock". Note that rather
700 than extending a basic instruction set, the extension mnemonics
701 starting with "no" revoke the respective functionality.
702 When the ".arch" directive is used with -march, the ".arch"
704 directive will take precedent.
705 -mtune=CPU
707 This option specifies a processor to optimize for. When used in
708 conjunction with the -march option, only instructions of the
709 processor specified by the -march option will be generated.
710 Valid CPU values are identical to the processor list of -march=CPU.
712 -msse2avx
714 This option specifies that the assembler should encode SSE
715 instructions with VEX prefix.
716 -msse-check=none
718 -msse-check=warning
719 -msse-check=error
720 These options control if the assembler should check SSE
721 instructions. -msse-check=none will make the assembler not to
722 check SSE instructions, which is the default. -msse-check=warning
723 will make the assembler issue a warning for any SSE instruction.
724 -msse-check=error will make the assembler issue an error for any
725 SSE instruction.
726 -mavxscalar=128
728 -mavxscalar=256
729 These options control how the assembler should encode scalar AVX
730 instructions. -mavxscalar=128 will encode scalar AVX instructions
731 with 128bit vector length, which is the default. -mavxscalar=256
732 will encode scalar AVX instructions with 256bit vector length.
733 -mevexlig=128
735 -mevexlig=256
736 -mevexlig=512
737 These options control how the assembler should encode length-
738 ignored (LIG) EVEX instructions. -mevexlig=128 will encode LIG
739 EVEX instructions with 128bit vector length, which is the default.
740 -mevexlig=256 and -mevexlig=512 will encode LIG EVEX instructions
741 with 256bit and 512bit vector length, respectively.
742 -mevexwig=0
744 -mevexwig=1
745 These options control how the assembler should encode w-ignored
746 (WIG) EVEX instructions. -mevexwig=0 will encode WIG EVEX
747 instructions with evex.w = 0, which is the default. -mevexwig=1
748 will encode WIG EVEX instructions with evex.w = 1.
749 -mmnemonic=att
751 -mmnemonic=intel
752 This option specifies instruction mnemonic for matching
753 instructions. The ".att_mnemonic" and ".intel_mnemonic" directives
754 will take precedent.
755 -msyntax=att
757 -msyntax=intel
758 This option specifies instruction syntax when processing
759 instructions. The ".att_syntax" and ".intel_syntax" directives
760 will take precedent.
761 -mnaked-reg
763 This opetion specifies that registers don't require a % prefix.
764 The ".att_syntax" and ".intel_syntax" directives will take
765 precedent.
766 -madd-bnd-prefix
768 This option forces the assembler to add BND prefix to all branches,
769 even if such prefix was not explicitly specified in the source
770 code.
771 The following options are available when as is configured for the Intel
773 80960 processor.
774 -ACA | -ACA_A | -ACB | -ACC | -AKA | -AKB | -AKC | -AMC
776 Specify which variant of the 960 architecture is the target.
777 -b Add code to collect statistics about branches taken.
779 -no-relax
781 Do not alter compare-and-branch instructions for long
782 displacements; error if necessary.
783 The following options are available when as is configured for the
785 Ubicom IP2K series.
786 -mip2022ext
788 Specifies that the extended IP2022 instructions are allowed.
789 -mip2022
791 Restores the default behaviour, which restricts the permitted
792 instructions to just the basic IP2022 ones.
793 The following options are available when as is configured for the
795 Renesas M32C and M16C processors.
796 -m32c
798 Assemble M32C instructions.
799 -m16c
801 Assemble M16C instructions (the default).
802 -relax
804 Enable support for link-time relaxations.
805 -h-tick-hex
807 Support H'00 style hex constants in addition to 0x00 style.
808 The following options are available when as is configured for the
810 Renesas M32R (formerly Mitsubishi M32R) series.
811 --m32rx
813 Specify which processor in the M32R family is the target. The
814 default is normally the M32R, but this option changes it to the
815 M32RX.
816 --warn-explicit-parallel-conflicts or --Wp
818 Produce warning messages when questionable parallel constructs are
819 encountered.
820 --no-warn-explicit-parallel-conflicts or --Wnp
822 Do not produce warning messages when questionable parallel
823 constructs are encountered.
824 The following options are available when as is configured for the
826 Motorola 68000 series.
827 -l Shorten references to undefined symbols, to one word instead of
829 two.
830 -m68000 | -m68008 | -m68010 | -m68020 | -m68030
832 | -m68040 | -m68060 | -m68302 | -m68331 | -m68332
833 | -m68333 | -m68340 | -mcpu32 | -m5200
834 Specify what processor in the 68000 family is the target. The
835 default is normally the 68020, but this can be changed at
836 configuration time.
837 -m68881 | -m68882 | -mno-68881 | -mno-68882
839 The target machine does (or does not) have a floating-point
840 coprocessor. The default is to assume a coprocessor for 68020,
841 68030, and cpu32. Although the basic 68000 is not compatible with
842 the 68881, a combination of the two can be specified, since it's
843 possible to do emulation of the coprocessor instructions with the
844 main processor.
845 -m68851 | -mno-68851
847 The target machine does (or does not) have a memory-management unit
848 coprocessor. The default is to assume an MMU for 68020 and up.
849 The following options are available when as is configured for an Altera
851 Nios II processor.
852 -relax-section
854 Replace identified out-of-range branches with PC-relative "jmp"
855 sequences when possible. The generated code sequences are suitable
856 for use in position-independent code, but there is a practical
857 limit on the extended branch range because of the length of the
858 sequences. This option is the default.
859 -relax-all
861 Replace branch instructions not determinable to be in range and all
862 call instructions with "jmp" and "callr" sequences (respectively).
863 This option generates absolute relocations against the target
864 symbols and is not appropriate for position-independent code.
865 -no-relax
867 Do not replace any branches or calls.
868 -EB Generate big-endian output.
870 -EL Generate little-endian output. This is the default.
872 The following options are available when as is configured for a Meta
874 processor.
875 "-mcpu=metac11"
877 Generate code for Meta 1.1.
878 "-mcpu=metac12"
880 Generate code for Meta 1.2.
881 "-mcpu=metac21"
883 Generate code for Meta 2.1.
884 "-mfpu=metac21"
886 Allow code to use FPU hardware of Meta 2.1.
887 See the info pages for documentation of the MMIX-specific options.
889 The following options are available when as is configured for a PowerPC
891 processor.
892 -a32
894 Generate ELF32 or XCOFF32.
895 -a64
897 Generate ELF64 or XCOFF64.
898 -K PIC
900 Set EF_PPC_RELOCATABLE_LIB in ELF flags.
901 -mpwrx | -mpwr2
903 Generate code for POWER/2 (RIOS2).
904 -mpwr
906 Generate code for POWER (RIOS1)
907 -m601
909 Generate code for PowerPC 601.
910 -mppc, -mppc32, -m603, -m604
912 Generate code for PowerPC 603/604.
913 -m403, -m405
915 Generate code for PowerPC 403/405.
916 -m440
918 Generate code for PowerPC 440. BookE and some 405 instructions.
919 -m464
921 Generate code for PowerPC 464.
922 -m476
924 Generate code for PowerPC 476.
925 -m7400, -m7410, -m7450, -m7455
927 Generate code for PowerPC 7400/7410/7450/7455.
928 -m750cl
930 Generate code for PowerPC 750CL.
931 -mppc64, -m620
933 Generate code for PowerPC 620/625/630.
934 -me500, -me500x2
936 Generate code for Motorola e500 core complex.
937 -me500mc
939 Generate code for Freescale e500mc core complex.
940 -me500mc64
942 Generate code for Freescale e500mc64 core complex.
943 -me5500
945 Generate code for Freescale e5500 core complex.
946 -me6500
948 Generate code for Freescale e6500 core complex.
949 -mspe
951 Generate code for Motorola SPE instructions.
952 -mtitan
954 Generate code for AppliedMicro Titan core complex.
955 -mppc64bridge
957 Generate code for PowerPC 64, including bridge insns.
958 -mbooke
960 Generate code for 32-bit BookE.
961 -ma2
963 Generate code for A2 architecture.
964 -me300
966 Generate code for PowerPC e300 family.
967 -maltivec
969 Generate code for processors with AltiVec instructions.
970 -mvle
972 Generate code for Freescale PowerPC VLE instructions.
973 -mvsx
975 Generate code for processors with Vector-Scalar (VSX) instructions.
976 -mhtm
978 Generate code for processors with Hardware Transactional Memory
979 instructions.
980 -mpower4, -mpwr4
982 Generate code for Power4 architecture.
983 -mpower5, -mpwr5, -mpwr5x
985 Generate code for Power5 architecture.
986 -mpower6, -mpwr6
988 Generate code for Power6 architecture.
989 -mpower7, -mpwr7
991 Generate code for Power7 architecture.
992 -mpower8, -mpwr8
994 Generate code for Power8 architecture.
995 -mcell
997 -mcell
998 Generate code for Cell Broadband Engine architecture.
999 -mcom
1001 Generate code Power/PowerPC common instructions.
1002 -many
1004 Generate code for any architecture (PWR/PWRX/PPC).
1005 -mregnames
1007 Allow symbolic names for registers.
1008 -mno-regnames
1010 Do not allow symbolic names for registers.
1011 -mrelocatable
1013 Support for GCC's -mrelocatable option.
1014 -mrelocatable-lib
1016 Support for GCC's -mrelocatable-lib option.
1017 -memb
1019 Set PPC_EMB bit in ELF flags.
1020 -mlittle, -mlittle-endian, -le
1022 Generate code for a little endian machine.
1023 -mbig, -mbig-endian, -be
1025 Generate code for a big endian machine.
1026 -msolaris
1028 Generate code for Solaris.
1029 -mno-solaris
1031 Do not generate code for Solaris.
1032 -nops=count
1034 If an alignment directive inserts more than count nops, put a
1035 branch at the beginning to skip execution of the nops.
1036 See the info pages for documentation of the RX-specific options.
1038 The following options are available when as is configured for the s390
1040 processor family.
1041 -m31
1043 -m64
1044 Select the word size, either 31/32 bits or 64 bits.
1045 -mesa
1047 -mzarch
1048 Select the architecture mode, either the Enterprise System
1049 Architecture (esa) or the z/Architecture mode (zarch).
1050 -march=processor
1052 Specify which s390 processor variant is the target, g6, g6, z900,
1053 z990, z9-109, z9-ec, z10, z196, or zEC12.
1054 -mregnames
1056 -mno-regnames
1057 Allow or disallow symbolic names for registers.
1058 -mwarn-areg-zero
1060 Warn whenever the operand for a base or index register has been
1061 specified but evaluates to zero.
1062 The following options are available when as is configured for a
1064 TMS320C6000 processor.
1065 -march=arch
1067 Enable (only) instructions from architecture arch. By default, all
1068 instructions are permitted.
1069 The following values of arch are accepted: "c62x", "c64x", "c64x+",
1071 "c67x", "c67x+", "c674x".
1072 -mdsbt
1074 -mno-dsbt
1075 The -mdsbt option causes the assembler to generate the
1076 "Tag_ABI_DSBT" attribute with a value of 1, indicating that the
1077 code is using DSBT addressing. The -mno-dsbt option, the default,
1078 causes the tag to have a value of 0, indicating that the code does
1079 not use DSBT addressing. The linker will emit a warning if objects
1080 of different type (DSBT and non-DSBT) are linked together.
1081 -mpid=no
1083 -mpid=near
1084 -mpid=far
1085 The -mpid= option causes the assembler to generate the
1086 "Tag_ABI_PID" attribute with a value indicating the form of data
1087 addressing used by the code. -mpid=no, the default, indicates
1088 position-dependent data addressing, -mpid=near indicates position-
1089 independent addressing with GOT accesses using near DP addressing,
1090 and -mpid=far indicates position-independent addressing with GOT
1091 accesses using far DP addressing. The linker will emit a warning
1092 if objects built with different settings of this option are linked
1093 together.
1094 -mpic
1096 -mno-pic
1097 The -mpic option causes the assembler to generate the "Tag_ABI_PIC"
1098 attribute with a value of 1, indicating that the code is using
1099 position-independent code addressing, The "-mno-pic" option, the
1100 default, causes the tag to have a value of 0, indicating position-
1101 dependent code addressing. The linker will emit a warning if
1102 objects of different type (position-dependent and position-
1103 independent) are linked together.
1104 -mbig-endian
1106 -mlittle-endian
1107 Generate code for the specified endianness. The default is little-
1108 endian.
1109 The following options are available when as is configured for a TILE-Gx
1111 processor.
1112 -m32 | -m64
1114 Select the word size, either 32 bits or 64 bits.
1115 -EB | -EL
1117 Select the endianness, either big-endian (-EB) or little-endian
1118 (-EL).
1119 The following options are available when as is configured for an Xtensa
1121 processor.
1122 --text-section-literals | --no-text-section-literals
1124 Control the treatment of literal pools. The default is
1125 --no-text-section-literals, which places literals in separate
1126 sections in the output file. This allows the literal pool to be
1127 placed in a data RAM/ROM. With --text-section-literals, the
1128 literals are interspersed in the text section in order to keep them
1129 as close as possible to their references. This may be necessary
1130 for large assembly files, where the literals would otherwise be out
1131 of range of the "L32R" instructions in the text section. These
1132 options only affect literals referenced via PC-relative "L32R"
1133 instructions; literals for absolute mode "L32R" instructions are
1134 handled separately.
1135 --absolute-literals | --no-absolute-literals
1137 Indicate to the assembler whether "L32R" instructions use absolute
1138 or PC-relative addressing. If the processor includes the absolute
1139 addressing option, the default is to use absolute "L32R"
1140 relocations. Otherwise, only the PC-relative "L32R" relocations
1141 can be used.
1142 --target-align | --no-target-align
1144 Enable or disable automatic alignment to reduce branch penalties at
1145 some expense in code size. This optimization is enabled by
1146 default. Note that the assembler will always align instructions
1147 like "LOOP" that have fixed alignment requirements.
1148 --longcalls | --no-longcalls
1150 Enable or disable transformation of call instructions to allow
1151 calls across a greater range of addresses. This option should be
1152 used when call targets can potentially be out of range. It may
1153 degrade both code size and performance, but the linker can
1154 generally optimize away the unnecessary overhead when a call ends
1155 up within range. The default is --no-longcalls.
1156 --transform | --no-transform
1158 Enable or disable all assembler transformations of Xtensa
1159 instructions, including both relaxation and optimization. The
1160 default is --transform; --no-transform should only be used in the
1161 rare cases when the instructions must be exactly as specified in
1162 the assembly source. Using --no-transform causes out of range
1163 instruction operands to be errors.
1164 --rename-section oldname=newname
1166 Rename the oldname section to newname. This option can be used
1167 multiple times to rename multiple sections.
1168 The following options are available when as is configured for a Z80
1170 family processor.
1171 -z80
1173 Assemble for Z80 processor.
1174 -r800
1176 Assemble for R800 processor.
1177 -ignore-undocumented-instructions
1179 -Wnud
1180 Assemble undocumented Z80 instructions that also work on R800
1181 without warning.
1182 -ignore-unportable-instructions
1184 -Wnup
1185 Assemble all undocumented Z80 instructions without warning.
1186 -warn-undocumented-instructions
1188 -Wud
1189 Issue a warning for undocumented Z80 instructions that also work on
1190 R800.
1191 -warn-unportable-instructions
1193 -Wup
1194 Issue a warning for undocumented Z80 instructions that do not work
1195 on R800.
1196 -forbid-undocumented-instructions
1198 -Fud
1199 Treat all undocumented instructions as errors.
1200 -forbid-unportable-instructions
1202 -Fup
1203 Treat undocumented Z80 instructions that do not work on R800 as
1204 errors.
1205
1207 gcc(1), ld(1), and the Info entries for binutils and ld.
1208
1210 Copyright (c) 1991-2013 Free Software Foundation, Inc.
1211 Permission is granted to copy, distribute and/or modify this document
1213 under the terms of the GNU Free Documentation License, Version 1.3 or
1214 any later version published by the Free Software Foundation; with no
1215 Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
1216 Texts. A copy of the license is included in the section entitled "GNU
1217 Free Documentation License".
1218binutils-2.24 2018-07-14 AS(1)