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GAS supports a general syntax that works for all of the supported architectures. The general syntax includes assembler directives and a method for commenting. The default syntax is
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451:. GAS is often used as the assembler on Linux operating systems in conjunction with other GNU software. A modified version of GAS can also be found in the
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Being the back-end for a popular compiler suite, namely GCC, the GNU Assembler is very widely used in compiling modern
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A new pseudo-op .intel_syntax has been implemented to allow gas to parse i386 assembly programs with intel syntax.
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Single line comments have a few different formats varying on which architecture is being assembled for.
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The first version of GAS was released in 1986–1987. It was written by Dean Elsner and supported the
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As in C, multi-line comments start and end with mirroring slash-asterisk pairs:
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630:# assign (current address - address of msg start) to symbol "len"
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Since version 2.10, Intel syntax can be used through use of the
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504:# 4 (code for "write" syscall) -> EAX register
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534:# 32-bit address of msg string -> ECX (2nd argument)
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884:: the portable GNU assembler –
188:, and various other software. It is a part of the
803:"Linux assemblers: A comparison of GAS and NASM"
1297:Free Software Foundation anti-Windows campaigns
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19:
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734:"The GNU Assembler - Assembler Directives"
549:# length of msg string -> EDX (3rd arg)
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467:A standard "Hello, world!" program for
776:"AT&T Syntax versus Intel Syntax"
7:
1015:GNAT Modified General Public License
805:. IBM DeveloperWorks. Archived from
650:Free and open-source software portal
14:
1005:GNU Affero General Public License
1000:GNU Lesser General Public License
280:GAS supports two comment styles.
642:
573:# 1 ("exit") -> EAX
455:development tools package since
25:
1562:Free compilers and interpreters
687:Nick Clifton (17 August 2024).
1376:Low-level programming language
1010:GNU Free Documentation License
689:"GNU Binutils 2.43.1 released"
663:Binary File Descriptor library
16:Free and open-source assembler
1:
449:free and open source software
180:. It is used to assemble the
1285:GNU/Linux naming controversy
588:# 0 (with success) -> EBX
609:"Hello, world!\n"
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983:GNU General Public License
801:Ram Narayan (2007-10-17).
223:GNU General Public License
205:, the standard name for a
122:GNU General Public License
1432:Microsoft Macro Assembler
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56:GNU Binutils 2.43.1
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1361:Comparison of assemblers
967:History of free software
945:Free Software Foundation
668:Comparison of assemblers
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290:
1572:Linux programming tools
1577:Unix programming tools
263:C programming language
215:computer architectures
1450:Open Watcom Assembler
1391:x86 assembly language
712:"The GNU Assembler".
612:# inline ascii string
64:; 26 days ago
1567:GNU Project software
1531:Instruction listings
759:"GNU Assembler News"
182:GNU operating system
172:. It is the default
156:, commonly known as
1526:Calling conventions
1426:High Level Assembly
1343:x86 assembly topics
1302:Defective by Design
1269:Richard M. Stallman
257:GAS uses assembler
221:released under the
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1521:Processor register
1234:Benjamin Mako Hill
209:assembler. GAS is
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1543:
1438:Netwide Assembler
1356:Assembly language
1310:
1309:
1254:Georg C. F. Greve
1161:GNU Privacy Guard
988:linking exception
168:developed by the
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861:Official website
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836:on June 20, 2011
832:. Archived from
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778:. Archived from
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736:. Archived from
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62:/ 17 August 2024
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1444:Turbo Assembler
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1371:Instruction set
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1239:Bradley M. Kuhn
1229:Alexandre Oliva
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463:Example program
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853:External links
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719:10.1.1.32.4503
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597:# see previous
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69:17 August 2024
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960:Latin America
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940:GNU Manifesto
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740:on 2012-02-22
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20:GNU Assembler
1419:
1381:Machine code
1366:Disassembler
1289:
1278:Other topics
1264:Nagarjuna G.
1222:Contributors
1211:
1186:GNU LilyPond
1146:GNU Electric
1071:Build system
838:. Retrieved
834:the original
823:
811:. Retrieved
807:the original
796:
784:. Retrieved
780:the original
770:
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742:. Retrieved
738:the original
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692:. Retrieved
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423:vertical bar
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190:GNU Binutils
186:Linux kernel
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35:Developer(s)
1460:Programming
1116:GNU TeXmacs
1046:Linux-libre
926:GNU Project
315:hash symbol
305:Single-line
272:directive.
170:GNU Project
40:GNU Project
1557:Assemblers
1551:Categories
1479:Carry flag
1469:Call stack
1401:Assemblers
1176:GNU Health
1121:GNU Octave
873:Gas manual
830:"Using as"
744:2008-04-13
674:References
437:Renesas SH
284:Multi-line
259:directives
253:Directives
197:executable
82:Written in
1536:Registers
1499:Zero flag
1244:Brian Fox
1196:GNU Chess
1126:GNU Taler
1111:GNU Emacs
1066:findutils
1061:coreutils
714:CiteSeerX
694:18 August
411:A double
369:semicolon
217:. GAS is
199:is named
192:package.
166:assembler
164:, is the
142:/binutils
140:/software
110:Assembler
1409:A86/A386
1166:Gnuzilla
1081:binutils
1035:variants
1024:Software
976:Licenses
636:See also
393:picoJava
383:family,
375:family,
276:Comments
195:The GAS
184:and the
174:back-end
93:Platform
1212:more...
1096:GNUstep
933:History
840:Jan 10,
813:28 July
786:28 July
489:_start:
480:.global
417:AArch64
415:(//) —
403:at sign
373:AMD 29k
351:PowerPC
296:comment
229:History
129:Website
117:License
67: (
1511:Opcode
1462:issues
1452:(WASM)
1446:(TASM)
1440:(NASM)
1434:(MASM)
1416:(FASM)
1349:Topics
1191:GNU Go
1181:GNUmed
1170:IceCat
1156:GNUnet
950:Europe
890:Manual
716:
606:.ascii
594:$ 0x80
555:$ 0x80
483:_start
435:(!) —
427:M680x0
425:(|) —
389:PDP-11
381:H8/300
371:(;) —
363:RISC-V
361:, and
359:M680x0
335:68HC12
331:68HC11
323:x86-64
317:(#) —
1474:Flags
1428:(HLA)
1422:(GAS)
1201:Gnash
1131:GNU R
1051:glibc
955:India
886:Linux
880:as(1)
600:.data
540:$ len
525:$ msg
486:.text
473:IA-32
469:Linux
453:macOS
443:Usage
413:slash
1206:Guix
1106:Jami
1101:GIMP
1091:GRUB
1056:Bash
1041:Hurd
842:2013
815:2014
788:2014
696:2024
603:msg:
585:%ebx
576:movl
570:%eax
561:movl
546:%edx
537:movl
531:%ecx
522:movl
516:%ebx
507:movl
501:%eax
492:movl
457:OS X
401:The
397:M32C
385:HPPA
355:MIPS
347:M32R
343:V850
327:i960
319:i386
225:v3.
207:Unix
152:The
138:.org
136:.gnu
105:Type
1141:GMP
1136:GSL
1086:GDB
1076:GCC
1031:GNU
627:msg
615:len
591:int
579:$ 0
564:$ 1
552:int
510:$ 1
495:$ 4
471:on
431:An
407:ARM
377:ARC
339:VAX
293:/*
235:VAX
178:GCC
176:of
160:or
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