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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 31359bab86e8fad55a7c0643a9984eb8b3b59d24 / . / docs / LangRef.html
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4<head>
5 <title>LLVM Assembly Language Reference Manual</title>
Reid Spencer3921c742004-08-26 20:44:00 +0000[diff] [blame]6 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
7 <meta name="author" content="Chris Lattner">
8 <meta name="description"
9 content="LLVM Assembly Language Reference Manual.">
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]10 <link rel="stylesheet" href="llvm.css" type="text/css">
11</head>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]14
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]15<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]16<ol>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]17 <li><a href="#abstract">Abstract</a></li>
18 <li><a href="#introduction">Introduction</a></li>
19 <li><a href="#identifiers">Identifiers</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]20 <li><a href="#highlevel">High Level Structure</a>
21 <ol>
22 <li><a href="#modulestructure">Module Structure</a></li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a></li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]24 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]25 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]26 <li><a href="#functionstructure">Functions</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]27 <li><a href="#aliasstructure">Aliases</a></li>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]28 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]29 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]30 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]31 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]32 <li><a href="#datalayout">Data Layout</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]33 </ol>
34 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]35 <li><a href="#typesystem">Type System</a>
36 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]37 <li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]38 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]39 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]40 <li><a href="#t_floating">Floating Point Types</a></li>
41 <li><a href="#t_void">Void Type</a></li>
42 <li><a href="#t_label">Label Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]43 </ol>
44 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]45 <li><a href="#t_derived">Derived Types</a>
46 <ol>
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]47 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]48 <li><a href="#t_array">Array Type</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]49 <li><a href="#t_function">Function Type</a></li>
50 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]51 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]52 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]53 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]54 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]55 </ol>
56 </li>
57 </ol>
58 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]59 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]60 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]61 <li><a href="#simpleconstants">Simple Constants</a></li>
62 <li><a href="#aggregateconstants">Aggregate Constants</a></li>
63 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
64 <li><a href="#undefvalues">Undefined Values</a></li>
65 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]66 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]67 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]68 <li><a href="#othervalues">Other Values</a>
69 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]70 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]71 </ol>
72 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]73 <li><a href="#instref">Instruction Reference</a>
74 <ol>
75 <li><a href="#terminators">Terminator Instructions</a>
76 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]77 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
78 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]79 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
80 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]81 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]82 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]83 </ol>
84 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]85 <li><a href="#binaryops">Binary Operations</a>
86 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]87 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
88 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
89 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]90 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
91 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
92 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]93 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
94 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
95 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]96 </ol>
97 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]98 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
99 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]100 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
101 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
102 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]103 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]104 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]105 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]106 </ol>
107 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]108 <li><a href="#vectorops">Vector Operations</a>
109 <ol>
110 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
111 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
112 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]113 </ol>
114 </li>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]115 <li><a href="#aggregateops">Aggregate Operations</a>
116 <ol>
117 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
118 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
119 </ol>
120 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]121 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]122 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]123 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
124 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
125 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]126 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
127 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
128 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]129 </ol>
130 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]131 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]132 <ol>
133 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
134 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
135 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
136 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
137 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]138 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
139 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
140 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
141 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]142 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
143 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]144 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]145 </ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]146 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]147 <li><a href="#otherops">Other Operations</a>
148 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]149 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
150 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]151 <li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
152 <li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]153 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]154 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]155 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]156 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]157 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]158 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]159 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]160 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]161 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]162 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]163 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
164 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]165 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
166 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
167 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]168 </ol>
169 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]170 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
171 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]172 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
173 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
174 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]175 </ol>
176 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]177 <li><a href="#int_codegen">Code Generator Intrinsics</a>
178 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]179 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
180 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
181 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
182 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
183 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
184 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
185 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]186 </ol>
187 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]188 <li><a href="#int_libc">Standard C Library Intrinsics</a>
189 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]190 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
191 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
192 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
193 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
194 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]195 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
196 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
197 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]198 </ol>
199 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]200 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]201 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]202 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]203 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
204 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
205 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]206 <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
207 <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]208 </ol>
209 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]210 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]211 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]212 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]213 <ol>
214 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]215 </ol>
216 </li>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]217 <li><a href="#int_atomics">Atomic intrinsics</a>
218 <ol>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]219 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]220 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]221 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]222 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
223 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
224 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
225 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
226 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
227 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
228 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
229 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
230 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
231 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]232 </ol>
233 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]234 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]235 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]236 <li><a href="#int_var_annotation">
Tanya Lattner91d0b882007-09-22 00:01:26 +0000[diff] [blame]237 <tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]238 <li><a href="#int_annotation">
Tanya Lattner91d0b882007-09-22 00:01:26 +0000[diff] [blame]239 <tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]240 <li><a href="#int_trap">
241 <tt>llvm.trap</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]242 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]243 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]244 </ol>
245 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]246</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]247
248<div class="doc_author">
249 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
250 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]251</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]252
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]253<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]254<div class="doc_section"> <a name="abstract">Abstract </a></div>
255<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]256
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]257<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]258<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling837f39b2008-08-05 22:29:16 +0000[diff] [blame]259LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]260type safety, low-level operations, flexibility, and the capability of
261representing 'all' high-level languages cleanly. It is the common code
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]262representation used throughout all phases of the LLVM compilation
263strategy.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]264</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]265
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]266<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]267<div class="doc_section"> <a name="introduction">Introduction</a> </div>
268<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]269
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]270<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]271
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]272<p>The LLVM code representation is designed to be used in three
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]273different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]274representation (suitable for fast loading by a Just-In-Time compiler),
275and as a human readable assembly language representation. This allows
276LLVM to provide a powerful intermediate representation for efficient
277compiler transformations and analysis, while providing a natural means
278to debug and visualize the transformations. The three different forms
279of LLVM are all equivalent. This document describes the human readable
280representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]281
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]282<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]283while being expressive, typed, and extensible at the same time. It
284aims to be a "universal IR" of sorts, by being at a low enough level
285that high-level ideas may be cleanly mapped to it (similar to how
286microprocessors are "universal IR's", allowing many source languages to
287be mapped to them). By providing type information, LLVM can be used as
288the target of optimizations: for example, through pointer analysis, it
289can be proven that a C automatic variable is never accessed outside of
290the current function... allowing it to be promoted to a simple SSA
291value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]292
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]293</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]294
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]295<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]296<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]297
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]298<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]299
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]300<p>It is important to note that this document describes 'well formed'
301LLVM assembly language. There is a difference between what the parser
302accepts and what is considered 'well formed'. For example, the
303following instruction is syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]304
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]305<div class="doc_code">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]306<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]307%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]308</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]309</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]310
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]311<p>...because the definition of <tt>%x</tt> does not dominate all of
312its uses. The LLVM infrastructure provides a verification pass that may
313be used to verify that an LLVM module is well formed. This pass is
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]314automatically run by the parser after parsing input assembly and by
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]315the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]316by the verifier pass indicate bugs in transformation passes or input to
317the parser.</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]318</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]319
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]320<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]321
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]322<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]323<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]324<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]325
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]326<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]327
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]328 <p>LLVM identifiers come in two basic types: global and local. Global
329 identifiers (functions, global variables) begin with the @ character. Local
330 identifiers (register names, types) begin with the % character. Additionally,
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]331 there are three different formats for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]332
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]333<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]334 <li>Named values are represented as a string of characters with their prefix.
335 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
336 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]337 Identifiers which require other characters in their names can be surrounded
Daniel Dunbar76dea952008-10-14 23:51:43 +0000[diff] [blame]338 with quotes. Special characters may be escaped using "\xx" where xx is the
339 ASCII code for the character in hexadecimal. In this way, any character can
340 be used in a name value, even quotes themselves.
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]341
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]342 <li>Unnamed values are represented as an unsigned numeric value with their
343 prefix. For example, %12, @2, %44.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]344
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]345 <li>Constants, which are described in a <a href="#constants">section about
346 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]347</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]348
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]349<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]350don't need to worry about name clashes with reserved words, and the set of
351reserved words may be expanded in the future without penalty. Additionally,
352unnamed identifiers allow a compiler to quickly come up with a temporary
353variable without having to avoid symbol table conflicts.</p>
354
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]355<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]356languages. There are keywords for different opcodes
357('<tt><a href="#i_add">add</a></tt>',
358 '<tt><a href="#i_bitcast">bitcast</a></tt>',
359 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names ('<tt><a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]360href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]361and others. These reserved words cannot conflict with variable names, because
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]362none of them start with a prefix character ('%' or '@').</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]363
364<p>Here is an example of LLVM code to multiply the integer variable
365'<tt>%X</tt>' by 8:</p>
366
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]367<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]368
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]369<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]370<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]371%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]372</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]373</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]374
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]375<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]376
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]377<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]378<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]379%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]380</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]381</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]382
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]383<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]384
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]385<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]386<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]387<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
388<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
389%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]390</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]391</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]392
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]393<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
394important lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]395
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]396<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]397
398 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
399 line.</li>
400
401 <li>Unnamed temporaries are created when the result of a computation is not
402 assigned to a named value.</li>
403
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]404 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]405
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]406</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]407
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]408<p>...and it also shows a convention that we follow in this document. When
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]409demonstrating instructions, we will follow an instruction with a comment that
410defines the type and name of value produced. Comments are shown in italic
411text.</p>
412
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]413</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]414
415<!-- *********************************************************************** -->
416<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
417<!-- *********************************************************************** -->
418
419<!-- ======================================================================= -->
420<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
421</div>
422
423<div class="doc_text">
424
425<p>LLVM programs are composed of "Module"s, each of which is a
426translation unit of the input programs. Each module consists of
427functions, global variables, and symbol table entries. Modules may be
428combined together with the LLVM linker, which merges function (and
429global variable) definitions, resolves forward declarations, and merges
430symbol table entries. Here is an example of the "hello world" module:</p>
431
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]432<div class="doc_code">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]433<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]434<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
435 href="#globalvars">constant</a> <a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]436
437<i>; External declaration of the puts function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]438<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]439
440<i>; Definition of main function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]441define i32 @main() { <i>; i32()* </i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]442 <i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]443 %cast210 = <a
Chris Lattner6c0955b2007-06-12 17:01:15 +0000[diff] [blame]444 href="#i_getelementptr">getelementptr</a> [13 x i8 ]* @.LC0, i64 0, i64 0 <i>; i8 *</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]445
446 <i>; Call puts function to write out the string to stdout...</i>
447 <a
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]448 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]449 <a
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]450 href="#i_ret">ret</a> i32 0<br>}<br>
451</pre>
452</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]453
454<p>This example is made up of a <a href="#globalvars">global variable</a>
455named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
456function, and a <a href="#functionstructure">function definition</a>
457for "<tt>main</tt>".</p>
458
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]459<p>In general, a module is made up of a list of global values,
460where both functions and global variables are global values. Global values are
461represented by a pointer to a memory location (in this case, a pointer to an
462array of char, and a pointer to a function), and have one of the following <a
463href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]464
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]465</div>
466
467<!-- ======================================================================= -->
468<div class="doc_subsection">
469 <a name="linkage">Linkage Types</a>
470</div>
471
472<div class="doc_text">
473
474<p>
475All Global Variables and Functions have one of the following types of linkage:
476</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]477
478<dl>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]479
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]480 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]481
482 <dd>Global values with internal linkage are only directly accessible by
483 objects in the current module. In particular, linking code into a module with
484 an internal global value may cause the internal to be renamed as necessary to
485 avoid collisions. Because the symbol is internal to the module, all
486 references can be updated. This corresponds to the notion of the
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]487 '<tt>static</tt>' keyword in C.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]488 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]489
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]490 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]491
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]492 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
493 the same name when linkage occurs. This is typically used to implement
494 inline functions, templates, or other code which must be generated in each
495 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
496 allowed to be discarded.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]497 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]498
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]499 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
500
501 <dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
502 linkage, except that unreferenced <tt>common</tt> globals may not be
503 discarded. This is used for globals that may be emitted in multiple
504 translation units, but that are not guaranteed to be emitted into every
505 translation unit that uses them. One example of this is tentative
506 definitions in C, such as "<tt>int X;</tt>" at global scope.
507 </dd>
508
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]509 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]510
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]511 <dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
512 that some targets may choose to emit different assembly sequences for them
513 for target-dependent reasons. This is used for globals that are declared
514 "weak" in C source code.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]515 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]516
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]517 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]518
519 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
520 pointer to array type. When two global variables with appending linkage are
521 linked together, the two global arrays are appended together. This is the
522 LLVM, typesafe, equivalent of having the system linker append together
523 "sections" with identical names when .o files are linked.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]524 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]525
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]526 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]527 <dd>The semantics of this linkage follow the ELF object file model: the
528 symbol is weak until linked, if not linked, the symbol becomes null instead
529 of being an undefined reference.
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]530 </dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]531
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]532 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]533
534 <dd>If none of the above identifiers are used, the global is externally
535 visible, meaning that it participates in linkage and can be used to resolve
536 external symbol references.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]537 </dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]538</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]539
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]540 <p>
541 The next two types of linkage are targeted for Microsoft Windows platform
542 only. They are designed to support importing (exporting) symbols from (to)
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]543 DLLs (Dynamic Link Libraries).
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]544 </p>
545
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]546 <dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]547 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
548
549 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
550 or variable via a global pointer to a pointer that is set up by the DLL
551 exporting the symbol. On Microsoft Windows targets, the pointer name is
552 formed by combining <code>_imp__</code> and the function or variable name.
553 </dd>
554
555 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
556
557 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
558 pointer to a pointer in a DLL, so that it can be referenced with the
559 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
560 name is formed by combining <code>_imp__</code> and the function or variable
561 name.
562 </dd>
563
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]564</dl>
565
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]566<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]567variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
568variable and was linked with this one, one of the two would be renamed,
569preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
570external (i.e., lacking any linkage declarations), they are accessible
Reid Spencerac8d2762007-01-05 00:59:10 +0000[diff] [blame]571outside of the current module.</p>
572<p>It is illegal for a function <i>declaration</i>
573to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]574or <tt>extern_weak</tt>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]575<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]576linkages.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]577</div>
578
579<!-- ======================================================================= -->
580<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]581 <a name="callingconv">Calling Conventions</a>
582</div>
583
584<div class="doc_text">
585
586<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
587and <a href="#i_invoke">invokes</a> can all have an optional calling convention
588specified for the call. The calling convention of any pair of dynamic
589caller/callee must match, or the behavior of the program is undefined. The
590following calling conventions are supported by LLVM, and more may be added in
591the future:</p>
592
593<dl>
594 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
595
596 <dd>This calling convention (the default if no other calling convention is
597 specified) matches the target C calling conventions. This calling convention
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]598 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencerc28d2bc2006-12-31 21:30:18 +0000[diff] [blame]599 prototype and implemented declaration of the function (as does normal C).
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]600 </dd>
601
602 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
603
604 <dd>This calling convention attempts to make calls as fast as possible
605 (e.g. by passing things in registers). This calling convention allows the
606 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]607 without having to conform to an externally specified ABI (Application Binary
608 Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer9097d142008-05-14 09:17:12 +0000[diff] [blame]609 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
610 supported. This calling convention does not support varargs and requires the
611 prototype of all callees to exactly match the prototype of the function
612 definition.
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]613 </dd>
614
615 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
616
617 <dd>This calling convention attempts to make code in the caller as efficient
618 as possible under the assumption that the call is not commonly executed. As
619 such, these calls often preserve all registers so that the call does not break
620 any live ranges in the caller side. This calling convention does not support
621 varargs and requires the prototype of all callees to exactly match the
622 prototype of the function definition.
623 </dd>
624
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]625 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]626
627 <dd>Any calling convention may be specified by number, allowing
628 target-specific calling conventions to be used. Target specific calling
629 conventions start at 64.
630 </dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]631</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]632
633<p>More calling conventions can be added/defined on an as-needed basis, to
634support pascal conventions or any other well-known target-independent
635convention.</p>
636
637</div>
638
639<!-- ======================================================================= -->
640<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]641 <a name="visibility">Visibility Styles</a>
642</div>
643
644<div class="doc_text">
645
646<p>
647All Global Variables and Functions have one of the following visibility styles:
648</p>
649
650<dl>
651 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
652
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]653 <dd>On targets that use the ELF object file format, default visibility means
654 that the declaration is visible to other
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]655 modules and, in shared libraries, means that the declared entity may be
656 overridden. On Darwin, default visibility means that the declaration is
657 visible to other modules. Default visibility corresponds to "external
658 linkage" in the language.
659 </dd>
660
661 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
662
663 <dd>Two declarations of an object with hidden visibility refer to the same
664 object if they are in the same shared object. Usually, hidden visibility
665 indicates that the symbol will not be placed into the dynamic symbol table,
666 so no other module (executable or shared library) can reference it
667 directly.
668 </dd>
669
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]670 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
671
672 <dd>On ELF, protected visibility indicates that the symbol will be placed in
673 the dynamic symbol table, but that references within the defining module will
674 bind to the local symbol. That is, the symbol cannot be overridden by another
675 module.
676 </dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]677</dl>
678
679</div>
680
681<!-- ======================================================================= -->
682<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]683 <a name="globalvars">Global Variables</a>
684</div>
685
686<div class="doc_text">
687
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]688<p>Global variables define regions of memory allocated at compilation time
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]689instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]690an explicit section to be placed in, and may have an optional explicit alignment
691specified. A variable may be defined as "thread_local", which means that it
692will not be shared by threads (each thread will have a separated copy of the
693variable). A variable may be defined as a global "constant," which indicates
694that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]695optimization, allowing the global data to be placed in the read-only section of
696an executable, etc). Note that variables that need runtime initialization
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]697cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]698
699<p>
700LLVM explicitly allows <em>declarations</em> of global variables to be marked
701constant, even if the final definition of the global is not. This capability
702can be used to enable slightly better optimization of the program, but requires
703the language definition to guarantee that optimizations based on the
704'constantness' are valid for the translation units that do not include the
705definition.
706</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]707
708<p>As SSA values, global variables define pointer values that are in
709scope (i.e. they dominate) all basic blocks in the program. Global
710variables always define a pointer to their "content" type because they
711describe a region of memory, and all memory objects in LLVM are
712accessed through pointers.</p>
713
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]714<p>A global variable may be declared to reside in a target-specifc numbered
715address space. For targets that support them, address spaces may affect how
716optimizations are performed and/or what target instructions are used to access
Christopher Lambd49e18d2007-12-12 08:44:39 +0000[diff] [blame]717the variable. The default address space is zero. The address space qualifier
718must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]719
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]720<p>LLVM allows an explicit section to be specified for globals. If the target
721supports it, it will emit globals to the section specified.</p>
722
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]723<p>An explicit alignment may be specified for a global. If not present, or if
724the alignment is set to zero, the alignment of the global is set by the target
725to whatever it feels convenient. If an explicit alignment is specified, the
726global is forced to have at least that much alignment. All alignments must be
727a power of 2.</p>
728
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]729<p>For example, the following defines a global in a numbered address space with
730an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]731
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]732<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]733<pre>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]734@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]735</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]736</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]737
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]738</div>
739
740
741<!-- ======================================================================= -->
742<div class="doc_subsection">
743 <a name="functionstructure">Functions</a>
744</div>
745
746<div class="doc_text">
747
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]748<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
749an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]750<a href="#visibility">visibility style</a>, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]751<a href="#callingconv">calling convention</a>, a return type, an optional
752<a href="#paramattrs">parameter attribute</a> for the return type, a function
753name, a (possibly empty) argument list (each with optional
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]754<a href="#paramattrs">parameter attributes</a>), optional
755<a href="#fnattrs">function attributes</a>, an optional section,
756an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner0c46a7d2008-10-04 18:10:21 +0000[diff] [blame]757an opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]758
759LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
760optional <a href="#linkage">linkage type</a>, an optional
761<a href="#visibility">visibility style</a>, an optional
762<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]763<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]764name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksene754abe2007-12-10 03:30:21 +0000[diff] [blame]765<a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]766
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]767<p>A function definition contains a list of basic blocks, forming the CFG
768(Control Flow Graph) for
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]769the function. Each basic block may optionally start with a label (giving the
770basic block a symbol table entry), contains a list of instructions, and ends
771with a <a href="#terminators">terminator</a> instruction (such as a branch or
772function return).</p>
773
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]774<p>The first basic block in a function is special in two ways: it is immediately
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]775executed on entrance to the function, and it is not allowed to have predecessor
776basic blocks (i.e. there can not be any branches to the entry block of a
777function). Because the block can have no predecessors, it also cannot have any
778<a href="#i_phi">PHI nodes</a>.</p>
779
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]780<p>LLVM allows an explicit section to be specified for functions. If the target
781supports it, it will emit functions to the section specified.</p>
782
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]783<p>An explicit alignment may be specified for a function. If not present, or if
784the alignment is set to zero, the alignment of the function is set by the target
785to whatever it feels convenient. If an explicit alignment is specified, the
786function is forced to have at least that much alignment. All alignments must be
787a power of 2.</p>
788
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]789 <h5>Syntax:</h5>
790
791<div class="doc_code">
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]792<tt>
793define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
794 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
795 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
796 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
797 [<a href="#gc">gc</a>] { ... }
798</tt>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]799</div>
800
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]801</div>
802
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]803
804<!-- ======================================================================= -->
805<div class="doc_subsection">
806 <a name="aliasstructure">Aliases</a>
807</div>
808<div class="doc_text">
809 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov726d45c2008-03-22 08:36:14 +0000[diff] [blame]810 function, global variable, another alias or bitcast of global value). Aliases
811 may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]812 optional <a href="#visibility">visibility style</a>.</p>
813
814 <h5>Syntax:</h5>
815
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]816<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]817<pre>
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]818@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]819</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]820</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]821
822</div>
823
824
825
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]826<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]827<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
828<div class="doc_text">
829 <p>The return type and each parameter of a function type may have a set of
830 <i>parameter attributes</i> associated with them. Parameter attributes are
831 used to communicate additional information about the result or parameters of
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]832 a function. Parameter attributes are considered to be part of the function,
833 not of the function type, so functions with different parameter attributes
834 can have the same function type.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]835
Reid Spencer950e9f82007-01-15 18:27:39 +0000[diff] [blame]836 <p>Parameter attributes are simple keywords that follow the type specified. If
837 multiple parameter attributes are needed, they are space separated. For
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]838 example:</p>
839
840<div class="doc_code">
841<pre>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]842declare i32 @printf(i8* noalias , ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]843declare i32 @atoi(i8 zeroext)
844declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]845</pre>
846</div>
847
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]848 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
849 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]850
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]851 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]852 <dl>
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]853 <dt><tt>zeroext</tt></dt>
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]854 <dd>This indicates to the code generator that the parameter or return value
855 should be zero-extended to a 32-bit value by the caller (for a parameter)
856 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]857
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]858 <dt><tt>signext</tt></dt>
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]859 <dd>This indicates to the code generator that the parameter or return value
860 should be sign-extended to a 32-bit value by the caller (for a parameter)
861 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]862
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]863 <dt><tt>inreg</tt></dt>
Dale Johannesenc9c6da62008-09-25 20:47:45 +0000[diff] [blame]864 <dd>This indicates that this parameter or return value should be treated
865 in a special target-dependent fashion during while emitting code for a
866 function call or return (usually, by putting it in a register as opposed
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]867 to memory, though some targets use it to distinguish between two different
868 kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]869
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]870 <dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner0747baa2008-01-15 04:34:22 +0000[diff] [blame]871 <dd>This indicates that the pointer parameter should really be passed by
872 value to the function. The attribute implies that a hidden copy of the
873 pointee is made between the caller and the callee, so the callee is unable
Chris Lattnerebec6782008-08-05 18:21:08 +0000[diff] [blame]874 to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner0747baa2008-01-15 04:34:22 +0000[diff] [blame]875 pointer arguments. It is generally used to pass structs and arrays by
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]876 value, but is also valid on pointers to scalars. The copy is considered to
877 belong to the caller not the callee (for example,
878 <tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]879 <tt>byval</tt> parameters). This is not a valid attribute for return
880 values. </dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]881
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]882 <dt><tt>sret</tt></dt>
Duncan Sandse26dec62008-02-18 04:19:38 +0000[diff] [blame]883 <dd>This indicates that the pointer parameter specifies the address of a
884 structure that is the return value of the function in the source program.
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]885 This pointer must be guaranteed by the caller to be valid: loads and stores
886 to the structure may be assumed by the callee to not to trap. This may only
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]887 be applied to the first parameter. This is not a valid attribute for
888 return values. </dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]889
Zhou Shengfebca342007-06-05 05:28:26 +0000[diff] [blame]890 <dt><tt>noalias</tt></dt>
Owen Anderson117bbd32008-02-18 04:09:01 +0000[diff] [blame]891 <dd>This indicates that the parameter does not alias any global or any other
892 parameter. The caller is responsible for ensuring that this is the case,
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]893 usually by placing the value in a stack allocation. This is not a valid
894 attribute for return values.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]895
Duncan Sands50f19f52007-07-27 19:57:41 +0000[diff] [blame]896 <dt><tt>nest</tt></dt>
Duncan Sands0789b8b2008-07-08 09:27:25 +0000[diff] [blame]897 <dd>This indicates that the pointer parameter can be excised using the
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]898 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
899 attribute for return values.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]900 </dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]901
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]902</div>
903
904<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]905<div class="doc_subsection">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]906 <a name="gc">Garbage Collector Names</a>
907</div>
908
909<div class="doc_text">
910<p>Each function may specify a garbage collector name, which is simply a
911string.</p>
912
913<div class="doc_code"><pre
914>define void @f() gc "name" { ...</pre></div>
915
916<p>The compiler declares the supported values of <i>name</i>. Specifying a
917collector which will cause the compiler to alter its output in order to support
918the named garbage collection algorithm.</p>
919</div>
920
921<!-- ======================================================================= -->
922<div class="doc_subsection">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]923 <a name="fnattrs">Function Attributes</a>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]924</div>
925
926<div class="doc_text">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]927
928<p>Function attributes are set to communicate additional information about
929 a function. Function attributes are considered to be part of the function,
930 not of the function type, so functions with different parameter attributes
931 can have the same function type.</p>
932
933 <p>Function attributes are simple keywords that follow the type specified. If
934 multiple attributes are needed, they are space separated. For
935 example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]936
937<div class="doc_code">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]938<pre>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]939define void @f() noinline { ... }
940define void @f() alwaysinline { ... }
941define void @f() alwaysinline optsize { ... }
942define void @f() optsize
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]943</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]944</div>
945
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]946<dl>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]947<dt><tt>alwaysinline</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]948<dd>This attribute indicates that the inliner should attempt to inline this
949function into callers whenever possible, ignoring any active inlining size
950threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]951
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]952<dt><tt>noinline</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]953<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner94b5f7d2008-10-05 17:14:59 +0000[diff] [blame]954in any situation. This attribute may not be used together with the
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]955<tt>alwaysinline</tt> attribute.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]956
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]957<dt><tt>optsize</tt></dt>
Devang Patel66c6c652008-09-29 18:34:44 +0000[diff] [blame]958<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]959make choices that keep the code size of this function low, and otherwise do
960optimizations specifically to reduce code size.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]961
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]962<dt><tt>noreturn</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]963<dd>This function attribute indicates that the function never returns normally.
964This produces undefined behavior at runtime if the function ever does
965dynamically return.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]966
967<dt><tt>nounwind</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]968<dd>This function attribute indicates that the function never returns with an
969unwind or exceptional control flow. If the function does unwind, its runtime
970behavior is undefined.</dd>
971
972<dt><tt>readnone</tt></dt>
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]973<dd>This attribute indicates that the function computes its result (or the
974exception it throws) based strictly on its arguments, without dereferencing any
975pointer arguments or otherwise accessing any mutable state (e.g. memory, control
976registers, etc) visible to caller functions. It does not write through any
977pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
978never changes any state visible to callers.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]979
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]980<dt><tt><a name="readonly">readonly</a></tt></dt>
981<dd>This attribute indicates that the function does not write through any
982pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
983or otherwise modify any state (e.g. memory, control registers, etc) visible to
984caller functions. It may dereference pointer arguments and read state that may
985be set in the caller. A readonly function always returns the same value (or
986throws the same exception) when called with the same set of arguments and global
987state.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame^]988
989<dt><tt><a name="ssp">ssp</a></tt></dt>
990<dd>This attribute indicates that the function should emit a stack smashing
991protector. It is in the form of a "canary"&mdash;a random value placed on the
992stack before the local variables that's checked upon return from the function to
993see if it has been overwritten. A heuristic is used to determine if a function
994needs stack protectors or not.</dd>
995
996<dt><tt>ssp-req</tt></dt>
997<dd>This attribute indicates that the function should <em>always</em> emit a
998stack smashing protector. This overrides the <tt><a href="#ssp">ssp</a></tt>
999function attribute.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1000</dl>
1001
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1002</div>
1003
1004<!-- ======================================================================= -->
1005<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1006 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1007</div>
1008
1009<div class="doc_text">
1010<p>
1011Modules may contain "module-level inline asm" blocks, which corresponds to the
1012GCC "file scope inline asm" blocks. These blocks are internally concatenated by
1013LLVM and treated as a single unit, but may be separated in the .ll file if
1014desired. The syntax is very simple:
1015</p>
1016
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1017<div class="doc_code">
1018<pre>
1019module asm "inline asm code goes here"
1020module asm "more can go here"
1021</pre>
1022</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1023
1024<p>The strings can contain any character by escaping non-printable characters.
1025 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
1026 for the number.
1027</p>
1028
1029<p>
1030 The inline asm code is simply printed to the machine code .s file when
1031 assembly code is generated.
1032</p>
1033</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1034
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1035<!-- ======================================================================= -->
1036<div class="doc_subsection">
1037 <a name="datalayout">Data Layout</a>
1038</div>
1039
1040<div class="doc_text">
1041<p>A module may specify a target specific data layout string that specifies how
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]1042data is to be laid out in memory. The syntax for the data layout is simply:</p>
1043<pre> target datalayout = "<i>layout specification</i>"</pre>
1044<p>The <i>layout specification</i> consists of a list of specifications
1045separated by the minus sign character ('-'). Each specification starts with a
1046letter and may include other information after the letter to define some
1047aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1048<dl>
1049 <dt><tt>E</tt></dt>
1050 <dd>Specifies that the target lays out data in big-endian form. That is, the
1051 bits with the most significance have the lowest address location.</dd>
1052 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1053 <dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1054 the bits with the least significance have the lowest address location.</dd>
1055 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1056 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
1057 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
1058 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
1059 too.</dd>
1060 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1061 <dd>This specifies the alignment for an integer type of a given bit
1062 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1063 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1064 <dd>This specifies the alignment for a vector type of a given bit
1065 <i>size</i>.</dd>
1066 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1067 <dd>This specifies the alignment for a floating point type of a given bit
1068 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1069 (double).</dd>
1070 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1071 <dd>This specifies the alignment for an aggregate type of a given bit
1072 <i>size</i>.</dd>
1073</dl>
1074<p>When constructing the data layout for a given target, LLVM starts with a
1075default set of specifications which are then (possibly) overriden by the
1076specifications in the <tt>datalayout</tt> keyword. The default specifications
1077are given in this list:</p>
1078<ul>
1079 <li><tt>E</tt> - big endian</li>
1080 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1081 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1082 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1083 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1084 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1085 <li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1086 alignment of 64-bits</li>
1087 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1088 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1089 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1090 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1091 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
1092</ul>
Chris Lattnerebec6782008-08-05 18:21:08 +0000[diff] [blame]1093<p>When LLVM is determining the alignment for a given type, it uses the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1094following rules:</p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1095<ol>
1096 <li>If the type sought is an exact match for one of the specifications, that
1097 specification is used.</li>
1098 <li>If no match is found, and the type sought is an integer type, then the
1099 smallest integer type that is larger than the bitwidth of the sought type is
1100 used. If none of the specifications are larger than the bitwidth then the the
1101 largest integer type is used. For example, given the default specifications
1102 above, the i7 type will use the alignment of i8 (next largest) while both
1103 i65 and i256 will use the alignment of i64 (largest specified).</li>
1104 <li>If no match is found, and the type sought is a vector type, then the
1105 largest vector type that is smaller than the sought vector type will be used
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1106 as a fall back. This happens because &lt;128 x double&gt; can be implemented
1107 in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1108</ol>
1109</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1110
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1111<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1112<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1113<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1114
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1115<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1116
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1117<p>The LLVM type system is one of the most important features of the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1118intermediate representation. Being typed enables a number of
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1119optimizations to be performed on the intermediate representation directly,
1120without having to do
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1121extra analyses on the side before the transformation. A strong type
1122system makes it easier to read the generated code and enables novel
1123analyses and transformations that are not feasible to perform on normal
1124three address code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1125
1126</div>
1127
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1128<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1129<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1130Classifications</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1131<div class="doc_text">
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1132<p>The types fall into a few useful
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1133classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1134
1135<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1136 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1137 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1138 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1139 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1140 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1141 </tr>
1142 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1143 <td><a href="#t_floating">floating point</a></td>
1144 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1145 </tr>
1146 <tr>
1147 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1148 <td><a href="#t_integer">integer</a>,
1149 <a href="#t_floating">floating point</a>,
1150 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1151 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1152 <a href="#t_struct">structure</a>,
1153 <a href="#t_array">array</a>,
Dan Gohmanade5faa2008-05-23 22:50:26 +0000[diff] [blame]1154 <a href="#t_label">label</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1155 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1156 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1157 <tr>
1158 <td><a href="#t_primitive">primitive</a></td>
1159 <td><a href="#t_label">label</a>,
1160 <a href="#t_void">void</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1161 <a href="#t_floating">floating point</a>.</td>
1162 </tr>
1163 <tr>
1164 <td><a href="#t_derived">derived</a></td>
1165 <td><a href="#t_integer">integer</a>,
1166 <a href="#t_array">array</a>,
1167 <a href="#t_function">function</a>,
1168 <a href="#t_pointer">pointer</a>,
1169 <a href="#t_struct">structure</a>,
1170 <a href="#t_pstruct">packed structure</a>,
1171 <a href="#t_vector">vector</a>,
1172 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1173 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1174 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1175 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1176</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1177
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1178<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1179most important. Values of these types are the only ones which can be
1180produced by instructions, passed as arguments, or used as operands to
Dan Gohmanc4b49eb2008-05-23 21:53:15 +0000[diff] [blame]1181instructions.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1182</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1183
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1184<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1185<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1186
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1187<div class="doc_text">
1188<p>The primitive types are the fundamental building blocks of the LLVM
1189system.</p>
1190
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1191</div>
1192
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1193<!-- _______________________________________________________________________ -->
1194<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1195
1196<div class="doc_text">
1197 <table>
1198 <tbody>
1199 <tr><th>Type</th><th>Description</th></tr>
1200 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1201 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1202 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1203 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1204 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1205 </tbody>
1206 </table>
1207</div>
1208
1209<!-- _______________________________________________________________________ -->
1210<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1211
1212<div class="doc_text">
1213<h5>Overview:</h5>
1214<p>The void type does not represent any value and has no size.</p>
1215
1216<h5>Syntax:</h5>
1217
1218<pre>
1219 void
1220</pre>
1221</div>
1222
1223<!-- _______________________________________________________________________ -->
1224<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1225
1226<div class="doc_text">
1227<h5>Overview:</h5>
1228<p>The label type represents code labels.</p>
1229
1230<h5>Syntax:</h5>
1231
1232<pre>
1233 label
1234</pre>
1235</div>
1236
1237
1238<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1239<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1240
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1241<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1242
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1243<p>The real power in LLVM comes from the derived types in the system.
1244This is what allows a programmer to represent arrays, functions,
1245pointers, and other useful types. Note that these derived types may be
1246recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1247
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1248</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1249
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1250<!-- _______________________________________________________________________ -->
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1251<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1252
1253<div class="doc_text">
1254
1255<h5>Overview:</h5>
1256<p>The integer type is a very simple derived type that simply specifies an
1257arbitrary bit width for the integer type desired. Any bit width from 1 bit to
12582^23-1 (about 8 million) can be specified.</p>
1259
1260<h5>Syntax:</h5>
1261
1262<pre>
1263 iN
1264</pre>
1265
1266<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1267value.</p>
1268
1269<h5>Examples:</h5>
1270<table class="layout">
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]1271 <tbody>
1272 <tr>
1273 <td><tt>i1</tt></td>
1274 <td>a single-bit integer.</td>
1275 </tr><tr>
1276 <td><tt>i32</tt></td>
1277 <td>a 32-bit integer.</td>
1278 </tr><tr>
1279 <td><tt>i1942652</tt></td>
1280 <td>a really big integer of over 1 million bits.</td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1281 </tr>
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]1282 </tbody>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1283</table>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1284</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1285
1286<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1287<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1288
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1289<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1290
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1291<h5>Overview:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1292
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1293<p>The array type is a very simple derived type that arranges elements
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1294sequentially in memory. The array type requires a size (number of
1295elements) and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1296
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1297<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1298
1299<pre>
1300 [&lt;# elements&gt; x &lt;elementtype&gt;]
1301</pre>
1302
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1303<p>The number of elements is a constant integer value; elementtype may
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1304be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1305
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1306<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1307<table class="layout">
1308 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1309 <td class="left"><tt>[40 x i32]</tt></td>
1310 <td class="left">Array of 40 32-bit integer values.</td>
1311 </tr>
1312 <tr class="layout">
1313 <td class="left"><tt>[41 x i32]</tt></td>
1314 <td class="left">Array of 41 32-bit integer values.</td>
1315 </tr>
1316 <tr class="layout">
1317 <td class="left"><tt>[4 x i8]</tt></td>
1318 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1319 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1320</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1321<p>Here are some examples of multidimensional arrays:</p>
1322<table class="layout">
1323 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1324 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1325 <td class="left">3x4 array of 32-bit integer values.</td>
1326 </tr>
1327 <tr class="layout">
1328 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1329 <td class="left">12x10 array of single precision floating point values.</td>
1330 </tr>
1331 <tr class="layout">
1332 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1333 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1334 </tr>
1335</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1336
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1337<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1338length array. Normally, accesses past the end of an array are undefined in
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1339LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1340As a special case, however, zero length arrays are recognized to be variable
1341length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1342type "{ i32, [0 x float]}", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1343
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1344</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1345
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1346<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1347<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1348<div class="doc_text">
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1349
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1350<h5>Overview:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1351
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1352<p>The function type can be thought of as a function signature. It
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1353consists of a return type and a list of formal parameter types. The
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1354return type of a function type is a scalar type, a void type, or a struct type.
Devang Patel7a3ad1a2008-03-24 20:52:42 +0000[diff] [blame]1355If the return type is a struct type then all struct elements must be of first
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1356class types, and the struct must have at least one element.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1357
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1358<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1359
1360<pre>
1361 &lt;returntype list&gt; (&lt;parameter list&gt;)
1362</pre>
1363
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1364<p>...where '<tt>&lt;parameter list&gt;</tt>' is a comma-separated list of type
Misha Brukmanc24b7582004-08-12 20:16:08 +0000[diff] [blame]1365specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1366which indicates that the function takes a variable number of arguments.
1367Variable argument functions can access their arguments with the <a
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1368 href="#int_varargs">variable argument handling intrinsic</a> functions.
1369'<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1370<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1371
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1372<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1373<table class="layout">
1374 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1375 <td class="left"><tt>i32 (i32)</tt></td>
1376 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1377 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1378 </tr><tr class="layout">
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]1379 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1380 </tt></td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1381 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1382 an <tt>i16</tt> that should be sign extended and a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1383 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1384 <tt>float</tt>.
1385 </td>
1386 </tr><tr class="layout">
1387 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1388 <td class="left">A vararg function that takes at least one
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1389 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1390 which returns an integer. This is the signature for <tt>printf</tt> in
1391 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1392 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1393 </tr><tr class="layout">
1394 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Devang Patel3a5bff82008-03-24 18:10:52 +0000[diff] [blame]1395 <td class="left">A function taking an <tt>i32></tt>, returning two
1396 <tt> i32 </tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1397 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1398 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1399</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1400
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1401</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1402<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1403<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1404<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1405<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1406<p>The structure type is used to represent a collection of data members
1407together in memory. The packing of the field types is defined to match
1408the ABI of the underlying processor. The elements of a structure may
1409be any type that has a size.</p>
1410<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1411and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1412field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1413instruction.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1414<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1415<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1416<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1417<table class="layout">
1418 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1419 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1420 <td class="left">A triple of three <tt>i32</tt> values</td>
1421 </tr><tr class="layout">
1422 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1423 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1424 second element is a <a href="#t_pointer">pointer</a> to a
1425 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1426 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1427 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1428</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1429</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1430
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1431<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1432<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1433</div>
1434<div class="doc_text">
1435<h5>Overview:</h5>
1436<p>The packed structure type is used to represent a collection of data members
1437together in memory. There is no padding between fields. Further, the alignment
1438of a packed structure is 1 byte. The elements of a packed structure may
1439be any type that has a size.</p>
1440<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1441and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1442field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1443instruction.</p>
1444<h5>Syntax:</h5>
1445<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1446<h5>Examples:</h5>
1447<table class="layout">
1448 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1449 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1450 <td class="left">A triple of three <tt>i32</tt> values</td>
1451 </tr><tr class="layout">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1452 <td class="left">
1453<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1454 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1455 second element is a <a href="#t_pointer">pointer</a> to a
1456 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1457 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1458 </tr>
1459</table>
1460</div>
1461
1462<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1463<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1464<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1465<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1466<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]1467reference to another object, which must live in memory. Pointer types may have
1468an optional address space attribute defining the target-specific numbered
1469address space where the pointed-to object resides. The default address space is
1470zero.</p>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1471<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1472<pre> &lt;type&gt; *<br></pre>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1473<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1474<table class="layout">
1475 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1476 <td class="left"><tt>[4x i32]*</tt></td>
1477 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1478 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1479 </tr>
1480 <tr class="layout">
1481 <td class="left"><tt>i32 (i32 *) *</tt></td>
1482 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1483 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1484 <tt>i32</tt>.</td>
1485 </tr>
1486 <tr class="layout">
1487 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1488 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1489 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1490 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1491</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1492</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1493
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1494<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1495<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1496<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1497
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1498<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1499
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1500<p>A vector type is a simple derived type that represents a vector
1501of elements. Vector types are used when multiple primitive data
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1502are operated in parallel using a single instruction (SIMD).
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1503A vector type requires a size (number of
Chris Lattnerb8d172f2005-11-10 01:44:22 +0000[diff] [blame]1504elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1505of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1506considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1507
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1508<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1509
1510<pre>
1511 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1512</pre>
1513
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1514<p>The number of elements is a constant integer value; elementtype may
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1515be any integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1516
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1517<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1518
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1519<table class="layout">
1520 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1521 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1522 <td class="left">Vector of 4 32-bit integer values.</td>
1523 </tr>
1524 <tr class="layout">
1525 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1526 <td class="left">Vector of 8 32-bit floating-point values.</td>
1527 </tr>
1528 <tr class="layout">
1529 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1530 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1531 </tr>
1532</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1533</div>
1534
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1535<!-- _______________________________________________________________________ -->
1536<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1537<div class="doc_text">
1538
1539<h5>Overview:</h5>
1540
1541<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksen8ac04ff2007-10-14 00:34:53 +0000[diff] [blame]1542corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1543In LLVM, opaque types can eventually be resolved to any type (not just a
1544structure type).</p>
1545
1546<h5>Syntax:</h5>
1547
1548<pre>
1549 opaque
1550</pre>
1551
1552<h5>Examples:</h5>
1553
1554<table class="layout">
1555 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1556 <td class="left"><tt>opaque</tt></td>
1557 <td class="left">An opaque type.</td>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1558 </tr>
1559</table>
1560</div>
1561
1562
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1563<!-- *********************************************************************** -->
1564<div class="doc_section"> <a name="constants">Constants</a> </div>
1565<!-- *********************************************************************** -->
1566
1567<div class="doc_text">
1568
1569<p>LLVM has several different basic types of constants. This section describes
1570them all and their syntax.</p>
1571
1572</div>
1573
1574<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1575<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1576
1577<div class="doc_text">
1578
1579<dl>
1580 <dt><b>Boolean constants</b></dt>
1581
1582 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1583 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1584 </dd>
1585
1586 <dt><b>Integer constants</b></dt>
1587
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1588 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1589 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1590 integer types.
1591 </dd>
1592
1593 <dt><b>Floating point constants</b></dt>
1594
1595 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1596 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]1597 notation (see below). The assembler requires the exact decimal value of
1598 a floating-point constant. For example, the assembler accepts 1.25 but
1599 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1600 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1601
1602 <dt><b>Null pointer constants</b></dt>
1603
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1604 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1605 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1606
1607</dl>
1608
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1609<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1610of floating point constants. For example, the form '<tt>double
16110x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
16124.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1613(and the only time that they are generated by the disassembler) is when a
1614floating point constant must be emitted but it cannot be represented as a
1615decimal floating point number. For example, NaN's, infinities, and other
1616special values are represented in their IEEE hexadecimal format so that
1617assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1618
1619</div>
1620
1621<!-- ======================================================================= -->
1622<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1623</div>
1624
1625<div class="doc_text">
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]1626<p>Aggregate constants arise from aggregation of simple constants
1627and smaller aggregate constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1628
1629<dl>
1630 <dt><b>Structure constants</b></dt>
1631
1632 <dd>Structure constants are represented with notation similar to structure
1633 type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner64910ee2007-12-25 20:34:52 +0000[diff] [blame]1634 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1635 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>". Structure constants
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]1636 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1637 types of elements must match those specified by the type.
1638 </dd>
1639
1640 <dt><b>Array constants</b></dt>
1641
1642 <dd>Array constants are represented with notation similar to array type
1643 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1644 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1645 constants must have <a href="#t_array">array type</a>, and the number and
1646 types of elements must match those specified by the type.
1647 </dd>
1648
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1649 <dt><b>Vector constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1650
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1651 <dd>Vector constants are represented with notation similar to vector type
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1652 definitions (a comma separated list of elements, surrounded by
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1653 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32 42,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1654 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1655 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1656 match those specified by the type.
1657 </dd>
1658
1659 <dt><b>Zero initialization</b></dt>
1660
1661 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1662 value to zero of <em>any</em> type, including scalar and aggregate types.
1663 This is often used to avoid having to print large zero initializers (e.g. for
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1664 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1665 initializers.
1666 </dd>
1667</dl>
1668
1669</div>
1670
1671<!-- ======================================================================= -->
1672<div class="doc_subsection">
1673 <a name="globalconstants">Global Variable and Function Addresses</a>
1674</div>
1675
1676<div class="doc_text">
1677
1678<p>The addresses of <a href="#globalvars">global variables</a> and <a
1679href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1680constants. These constants are explicitly referenced when the <a
1681href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1682href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1683file:</p>
1684
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1685<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1686<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]1687@X = global i32 17
1688@Y = global i32 42
1689@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1690</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1691</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1692
1693</div>
1694
1695<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1696<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1697<div class="doc_text">
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1698 <p>The string '<tt>undef</tt>' is recognized as a type-less constant that has
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1699 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1700 a constant is permitted.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1701
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1702 <p>Undefined values indicate to the compiler that the program is well defined
1703 no matter what value is used, giving the compiler more freedom to optimize.
1704 </p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1705</div>
1706
1707<!-- ======================================================================= -->
1708<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1709</div>
1710
1711<div class="doc_text">
1712
1713<p>Constant expressions are used to allow expressions involving other constants
1714to be used as constants. Constant expressions may be of any <a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1715href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1716that does not have side effects (e.g. load and call are not supported). The
1717following is the syntax for constant expressions:</p>
1718
1719<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1720 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1721 <dd>Truncate a constant to another type. The bit size of CST must be larger
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1722 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1723
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1724 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1725 <dd>Zero extend a constant to another type. The bit size of CST must be
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1726 smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1727
1728 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1729 <dd>Sign extend a constant to another type. The bit size of CST must be
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1730 smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1731
1732 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1733 <dd>Truncate a floating point constant to another floating point type. The
1734 size of CST must be larger than the size of TYPE. Both types must be
1735 floating point.</dd>
1736
1737 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1738 <dd>Floating point extend a constant to another type. The size of CST must be
1739 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1740
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]1741 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1742 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1743 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1744 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1745 of the same number of elements. If the value won't fit in the integer type,
1746 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1747
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1748 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1749 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1750 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1751 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1752 of the same number of elements. If the value won't fit in the integer type,
1753 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1754
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1755 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1756 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1757 constant. TYPE must be a scalar or vector floating point type. CST must be of
1758 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1759 of the same number of elements. If the value won't fit in the floating point
1760 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1761
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1762 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1763 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1764 constant. TYPE must be a scalar or vector floating point type. CST must be of
1765 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1766 of the same number of elements. If the value won't fit in the floating point
1767 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1768
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1769 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1770 <dd>Convert a pointer typed constant to the corresponding integer constant
1771 TYPE must be an integer type. CST must be of pointer type. The CST value is
1772 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1773
1774 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1775 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1776 pointer type. CST must be of integer type. The CST value is zero extended,
1777 truncated, or unchanged to make it fit in a pointer size. This one is
1778 <i>really</i> dangerous!</dd>
1779
1780 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1781 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1782 identical (same number of bits). The conversion is done as if the CST value
1783 was stored to memory and read back as TYPE. In other words, no bits change
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1784 with this operator, just the type. This can be used for conversion of
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1785 vector types to any other type, as long as they have the same bit width. For
Dan Gohman500233a2008-09-08 16:45:59 +0000[diff] [blame]1786 pointers it is only valid to cast to another pointer type. It is not valid
1787 to bitcast to or from an aggregate type.
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1788 </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1789
1790 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1791
1792 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1793 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1794 instruction, the index list may have zero or more indexes, which are required
1795 to make sense for the type of "CSTPTR".</dd>
1796
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1797 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1798
1799 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1800 constants.</dd>
1801
1802 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1803 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1804
1805 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1806 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1807
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]1808 <dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
1809 <dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
1810
1811 <dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
1812 <dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
1813
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1814 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1815
1816 <dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1817 operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1818
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1819 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1820
1821 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1822 operation</a> on constants.</dd>
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1823
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1824
1825 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1826
1827 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1828 operation</a> on constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1829
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1830 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1831
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1832 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1833 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1834 binary</a> operations. The constraints on operands are the same as those for
1835 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1836 values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1837</dl>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1838</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]1839
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1840<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1841<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1842<!-- *********************************************************************** -->
1843
1844<!-- ======================================================================= -->
1845<div class="doc_subsection">
1846<a name="inlineasm">Inline Assembler Expressions</a>
1847</div>
1848
1849<div class="doc_text">
1850
1851<p>
1852LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1853Module-Level Inline Assembly</a>) through the use of a special value. This
1854value represents the inline assembler as a string (containing the instructions
1855to emit), a list of operand constraints (stored as a string), and a flag that
1856indicates whether or not the inline asm expression has side effects. An example
1857inline assembler expression is:
1858</p>
1859
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1860<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1861<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1862i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1863</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1864</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1865
1866<p>
1867Inline assembler expressions may <b>only</b> be used as the callee operand of
1868a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
1869</p>
1870
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1871<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1872<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1873%X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y)
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1874</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1875</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1876
1877<p>
1878Inline asms with side effects not visible in the constraint list must be marked
1879as having side effects. This is done through the use of the
1880'<tt>sideeffect</tt>' keyword, like so:
1881</p>
1882
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1883<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1884<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1885call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1886</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1887</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1888
1889<p>TODO: The format of the asm and constraints string still need to be
1890documented here. Constraints on what can be done (e.g. duplication, moving, etc
Chris Lattner4f993352008-10-04 18:36:02 +0000[diff] [blame]1891need to be documented). This is probably best done by reference to another
1892document that covers inline asm from a holistic perspective.
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1893</p>
1894
1895</div>
1896
1897<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1898<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
1899<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1900
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1901<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1902
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1903<p>The LLVM instruction set consists of several different
1904classifications of instructions: <a href="#terminators">terminator
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1905instructions</a>, <a href="#binaryops">binary instructions</a>,
1906<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1907 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
1908instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1909
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1910</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1911
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1912<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1913<div class="doc_subsection"> <a name="terminators">Terminator
1914Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1915
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1916<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1917
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1918<p>As mentioned <a href="#functionstructure">previously</a>, every
1919basic block in a program ends with a "Terminator" instruction, which
1920indicates which block should be executed after the current block is
1921finished. These terminator instructions typically yield a '<tt>void</tt>'
1922value: they produce control flow, not values (the one exception being
1923the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1924<p>There are six different terminator instructions: the '<a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1925 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
1926instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1927the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
1928 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
1929 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1930
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1931</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1932
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1933<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1934<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
1935Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1936<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1937<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]1938<pre>
1939 ret &lt;type&gt; &lt;value&gt; <i>; Return a value from a non-void function</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1940 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1941</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1942
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1943<h5>Overview:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1944
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]1945<p>The '<tt>ret</tt>' instruction is used to return control flow (and
1946optionally a value) from a function back to the caller.</p>
John Criswell4457dc92004-04-09 16:48:45 +0000[diff] [blame]1947<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]1948returns a value and then causes control flow, and one that just causes
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1949control flow to occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1950
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1951<h5>Arguments:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1952
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]1953<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
1954the return value. The type of the return value must be a
1955'<a href="#t_firstclass">first class</a>' type.</p>
1956
1957<p>A function is not <a href="#wellformed">well formed</a> if
1958it it has a non-void return type and contains a '<tt>ret</tt>'
1959instruction with no return value or a return value with a type that
1960does not match its type, or if it has a void return type and contains
1961a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1962
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1963<h5>Semantics:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1964
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1965<p>When the '<tt>ret</tt>' instruction is executed, control flow
1966returns back to the calling function's context. If the caller is a "<a
John Criswellfa081872004-06-25 15:16:57 +0000[diff] [blame]1967 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1968the instruction after the call. If the caller was an "<a
1969 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1970at the beginning of the "normal" destination block. If the instruction
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1971returns a value, that value shall set the call or invoke instruction's
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1972return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1973
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1974<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1975
1976<pre>
1977 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1978 ret void <i>; Return from a void function</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]1979 ret { i32, i8 } { i32 4, i8 2 } <i>; Return an aggregate of values 4 and 2</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1980</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1981</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1982<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1983<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1984<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1985<h5>Syntax:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1986<pre> br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;<br> br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1987</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1988<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1989<p>The '<tt>br</tt>' instruction is used to cause control flow to
1990transfer to a different basic block in the current function. There are
1991two forms of this instruction, corresponding to a conditional branch
1992and an unconditional branch.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1993<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1994<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1995single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1996unconditional form of the '<tt>br</tt>' instruction takes a single
1997'<tt>label</tt>' value as a target.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1998<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1999<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2000argument is evaluated. If the value is <tt>true</tt>, control flows
2001to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2002control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2003<h5>Example:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2004<pre>Test:<br> %cond = <a href="#i_icmp">icmp</a> eq, i32 %a, %b<br> br i1 %cond, label %IfEqual, label %IfUnequal<br>IfEqual:<br> <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2005 href="#i_ret">ret</a> i32 1<br>IfUnequal:<br> <a href="#i_ret">ret</a> i32 0<br></pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2006</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2007<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2008<div class="doc_subsubsection">
2009 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2010</div>
2011
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2012<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2013<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2014
2015<pre>
2016 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2017</pre>
2018
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2019<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2020
2021<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
2022several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2023instruction, allowing a branch to occur to one of many possible
2024destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2025
2026
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2027<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2028
2029<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
2030comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
2031an array of pairs of comparison value constants and '<tt>label</tt>'s. The
2032table is not allowed to contain duplicate constant entries.</p>
2033
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2034<h5>Semantics:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2035
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2036<p>The <tt>switch</tt> instruction specifies a table of values and
2037destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]2038table is searched for the given value. If the value is found, control flow is
2039transfered to the corresponding destination; otherwise, control flow is
2040transfered to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2041
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2042<h5>Implementation:</h5>
2043
2044<p>Depending on properties of the target machine and the particular
2045<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]2046ways. For example, it could be generated as a series of chained conditional
2047branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2048
2049<h5>Example:</h5>
2050
2051<pre>
2052 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2053 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2054 switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2055
2056 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2057 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2058
2059 <i>; Implement a jump table:</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2060 switch i32 %val, label %otherwise [ i32 0, label %onzero
2061 i32 1, label %onone
2062 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2063</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2064</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2065
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2066<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2067<div class="doc_subsubsection">
2068 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2069</div>
2070
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2071<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2072
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2073<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2074
2075<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2076 &lt;result&gt; = invoke [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] &lt;ptr to function ty&gt; &lt;function ptr val&gt;(&lt;function args&gt;) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner76b8a332006-05-14 18:23:06 +0000[diff] [blame]2077 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2078</pre>
2079
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2080<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2081
2082<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
2083function, with the possibility of control flow transfer to either the
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2084'<tt>normal</tt>' label or the
2085'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2086"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
2087"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2088href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]2089continued at the dynamically nearest "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2090
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2091<h5>Arguments:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2092
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2093<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2094
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2095<ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2096 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]2097 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2098 convention</a> the call should use. If none is specified, the call defaults
2099 to using C calling conventions.
2100 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2101
2102 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
2103 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
2104 and '<tt>inreg</tt>' attributes are valid here.</li>
2105
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2106 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
2107 function value being invoked. In most cases, this is a direct function
2108 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
2109 an arbitrary pointer to function value.
2110 </li>
2111
2112 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
2113 function to be invoked. </li>
2114
2115 <li>'<tt>function args</tt>': argument list whose types match the function
2116 signature argument types. If the function signature indicates the function
2117 accepts a variable number of arguments, the extra arguments can be
2118 specified. </li>
2119
2120 <li>'<tt>normal label</tt>': the label reached when the called function
2121 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
2122
2123 <li>'<tt>exception label</tt>': the label reached when a callee returns with
2124 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
2125
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2126 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2127 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2128 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2129</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2130
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2131<h5>Semantics:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2132
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2133<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2134href="#i_call">call</a></tt>' instruction in most regards. The primary
2135difference is that it establishes an association with a label, which is used by
2136the runtime library to unwind the stack.</p>
2137
2138<p>This instruction is used in languages with destructors to ensure that proper
2139cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2140exception. Additionally, this is important for implementation of
2141'<tt>catch</tt>' clauses in high-level languages that support them.</p>
2142
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2143<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2144<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2145 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2146 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2147 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2148 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2149</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2150</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2151
2152
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2153<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2154
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2155<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2156Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2157
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2158<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2159
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2160<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2161<pre>
2162 unwind
2163</pre>
2164
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2165<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2166
2167<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
2168at the first callee in the dynamic call stack which used an <a
2169href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
2170primarily used to implement exception handling.</p>
2171
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2172<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2173
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]2174<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2175immediately halt. The dynamic call stack is then searched for the first <a
2176href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
2177execution continues at the "exceptional" destination block specified by the
2178<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
2179dynamic call chain, undefined behavior results.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2180</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2181
2182<!-- _______________________________________________________________________ -->
2183
2184<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2185Instruction</a> </div>
2186
2187<div class="doc_text">
2188
2189<h5>Syntax:</h5>
2190<pre>
2191 unreachable
2192</pre>
2193
2194<h5>Overview:</h5>
2195
2196<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
2197instruction is used to inform the optimizer that a particular portion of the
2198code is not reachable. This can be used to indicate that the code after a
2199no-return function cannot be reached, and other facts.</p>
2200
2201<h5>Semantics:</h5>
2202
2203<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
2204</div>
2205
2206
2207
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2208<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2209<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2210<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2211<p>Binary operators are used to do most of the computation in a
Chris Lattner5a158142008-04-01 18:47:32 +0000[diff] [blame]2212program. They require two operands of the same type, execute an operation on them, and
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2213produce a single value. The operands might represent
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2214multiple data, as is the case with the <a href="#t_vector">vector</a> data type.
Chris Lattner5a158142008-04-01 18:47:32 +0000[diff] [blame]2215The result value has the same type as its operands.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2216<p>There are several different binary operators:</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2217</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2218<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2219<div class="doc_subsubsection">
2220 <a name="i_add">'<tt>add</tt>' Instruction</a>
2221</div>
2222
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2223<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2224
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2225<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2226
2227<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2228 &lt;result&gt; = add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2229</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2230
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2231<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2232
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2233<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2234
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2235<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2236
2237<p>The two arguments to the '<tt>add</tt>' instruction must be <a
2238 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
2239 <a href="#t_vector">vector</a> values. Both arguments must have identical
2240 types.</p>
2241
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2242<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2243
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2244<p>The value produced is the integer or floating point sum of the two
2245operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2246
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2247<p>If an integer sum has unsigned overflow, the result returned is the
2248mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2249the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2250
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2251<p>Because LLVM integers use a two's complement representation, this
2252instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2253
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2254<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2255
2256<pre>
2257 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2258</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2259</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2260<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2261<div class="doc_subsubsection">
2262 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2263</div>
2264
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2265<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2266
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2267<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2268
2269<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2270 &lt;result&gt; = sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2271</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2272
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2273<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2274
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2275<p>The '<tt>sub</tt>' instruction returns the difference of its two
2276operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2277
2278<p>Note that the '<tt>sub</tt>' instruction is used to represent the
2279'<tt>neg</tt>' instruction present in most other intermediate
2280representations.</p>
2281
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2282<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2283
2284<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
2285 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2286 or <a href="#t_vector">vector</a> values. Both arguments must have identical
2287 types.</p>
2288
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2289<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2290
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2291<p>The value produced is the integer or floating point difference of
2292the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2293
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2294<p>If an integer difference has unsigned overflow, the result returned is the
2295mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2296the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2297
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2298<p>Because LLVM integers use a two's complement representation, this
2299instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2300
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2301<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2302<pre>
2303 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2304 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2305</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2306</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2307
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2308<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2309<div class="doc_subsubsection">
2310 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2311</div>
2312
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2313<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2314
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2315<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2316<pre> &lt;result&gt; = mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2317</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2318<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2319<p>The '<tt>mul</tt>' instruction returns the product of its two
2320operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2321
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2322<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2323
2324<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
2325href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2326or <a href="#t_vector">vector</a> values. Both arguments must have identical
2327types.</p>
2328
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2329<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2330
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2331<p>The value produced is the integer or floating point product of the
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2332two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2333
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2334<p>If the result of an integer multiplication has unsigned overflow,
2335the result returned is the mathematical result modulo
23362<sup>n</sup>, where n is the bit width of the result.</p>
2337<p>Because LLVM integers use a two's complement representation, and the
2338result is the same width as the operands, this instruction returns the
2339correct result for both signed and unsigned integers. If a full product
2340(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
2341should be sign-extended or zero-extended as appropriate to the
2342width of the full product.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2343<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2344<pre> &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2345</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2346</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2347
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2348<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2349<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2350</a></div>
2351<div class="doc_text">
2352<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2353<pre> &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2354</pre>
2355<h5>Overview:</h5>
2356<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2357operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2358
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2359<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2360
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2361<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2362<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2363values. Both arguments must have identical types.</p>
2364
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2365<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2366
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2367<p>The value produced is the unsigned integer quotient of the two operands.</p>
2368<p>Note that unsigned integer division and signed integer division are distinct
2369operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2370<p>Division by zero leads to undefined behavior.</p>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2371<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2372<pre> &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2373</pre>
2374</div>
2375<!-- _______________________________________________________________________ -->
2376<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2377</a> </div>
2378<div class="doc_text">
2379<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2380<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2381 &lt;result&gt; = sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2382</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2383
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2384<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2385
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2386<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2387operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2388
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2389<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2390
2391<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2392<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2393values. Both arguments must have identical types.</p>
2394
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2395<h5>Semantics:</h5>
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2396<p>The value produced is the signed integer quotient of the two operands rounded towards zero.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2397<p>Note that signed integer division and unsigned integer division are distinct
2398operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2399<p>Division by zero leads to undefined behavior. Overflow also leads to
2400undefined behavior; this is a rare case, but can occur, for example,
2401by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2402<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2403<pre> &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2404</pre>
2405</div>
2406<!-- _______________________________________________________________________ -->
2407<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2408Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2409<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2410<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2411<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2412 &lt;result&gt; = fdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2413</pre>
2414<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2415
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2416<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2417operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2418
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2419<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2420
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2421<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2422<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2423of floating point values. Both arguments must have identical types.</p>
2424
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2425<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2426
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2427<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2428
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2429<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2430
2431<pre>
2432 &lt;result&gt; = fdiv float 4.0, %var <i>; yields {float}:result = 4.0 / %var</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2433</pre>
2434</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2435
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2436<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2437<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2438</div>
2439<div class="doc_text">
2440<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2441<pre> &lt;result&gt; = urem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2442</pre>
2443<h5>Overview:</h5>
2444<p>The '<tt>urem</tt>' instruction returns the remainder from the
2445unsigned division of its two arguments.</p>
2446<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2447<p>The two arguments to the '<tt>urem</tt>' instruction must be
2448<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2449values. Both arguments must have identical types.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2450<h5>Semantics:</h5>
2451<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2452This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2453<p>Note that unsigned integer remainder and signed integer remainder are
2454distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
2455<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2456<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2457<pre> &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2458</pre>
2459
2460</div>
2461<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2462<div class="doc_subsubsection">
2463 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
2464</div>
2465
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2466<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2467
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2468<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2469
2470<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2471 &lt;result&gt; = srem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2472</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2473
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2474<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2475
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2476<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2477signed division of its two operands. This instruction can also take
2478<a href="#t_vector">vector</a> versions of the values in which case
2479the elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]2480
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2481<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2482
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2483<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2484<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2485values. Both arguments must have identical types.</p>
2486
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2487<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2488
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2489<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2490has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
2491operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2492a value. For more information about the difference, see <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2493 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2494Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencer64f5c6c2007-03-24 22:40:44 +0000[diff] [blame]2495please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2496Wikipedia: modulo operation</a>.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2497<p>Note that signed integer remainder and unsigned integer remainder are
2498distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
2499<p>Taking the remainder of a division by zero leads to undefined behavior.
2500Overflow also leads to undefined behavior; this is a rare case, but can occur,
2501for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
2502(The remainder doesn't actually overflow, but this rule lets srem be
2503implemented using instructions that return both the result of the division
2504and the remainder.)</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2505<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2506<pre> &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2507</pre>
2508
2509</div>
2510<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2511<div class="doc_subsubsection">
2512 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
2513
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2514<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2515
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2516<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2517<pre> &lt;result&gt; = frem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2518</pre>
2519<h5>Overview:</h5>
2520<p>The '<tt>frem</tt>' instruction returns the remainder from the
2521division of its two operands.</p>
2522<h5>Arguments:</h5>
2523<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2524<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2525of floating point values. Both arguments must have identical types.</p>
2526
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2527<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2528
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2529<p>This instruction returns the <i>remainder</i> of a division.
2530The remainder has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2531
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2532<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2533
2534<pre>
2535 &lt;result&gt; = frem float 4.0, %var <i>; yields {float}:result = 4.0 % %var</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2536</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2537</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]2538
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2539<!-- ======================================================================= -->
2540<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2541Operations</a> </div>
2542<div class="doc_text">
2543<p>Bitwise binary operators are used to do various forms of
2544bit-twiddling in a program. They are generally very efficient
2545instructions and can commonly be strength reduced from other
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2546instructions. They require two operands of the same type, execute an operation on them,
2547and produce a single value. The resulting value is the same type as its operands.</p>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2548</div>
2549
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2550<!-- _______________________________________________________________________ -->
2551<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2552Instruction</a> </div>
2553<div class="doc_text">
2554<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2555<pre> &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2556</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2557
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2558<h5>Overview:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2559
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2560<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2561the left a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2562
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2563<h5>Arguments:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2564
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2565<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2566 href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2567type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2568
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2569<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2570
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2571<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
2572where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
2573equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2574
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2575<h5>Example:</h5><pre>
2576 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2577 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2578 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2579 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2580</pre>
2581</div>
2582<!-- _______________________________________________________________________ -->
2583<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2584Instruction</a> </div>
2585<div class="doc_text">
2586<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2587<pre> &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2588</pre>
2589
2590<h5>Overview:</h5>
2591<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2592operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2593
2594<h5>Arguments:</h5>
2595<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2596<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2597type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2598
2599<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2600
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2601<p>This instruction always performs a logical shift right operation. The most
2602significant bits of the result will be filled with zero bits after the
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2603shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
2604the number of bits in <tt>op1</tt>, the result is undefined.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2605
2606<h5>Example:</h5>
2607<pre>
2608 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2609 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2610 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2611 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2612 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2613</pre>
2614</div>
2615
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2616<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2617<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2618Instruction</a> </div>
2619<div class="doc_text">
2620
2621<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2622<pre> &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2623</pre>
2624
2625<h5>Overview:</h5>
2626<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2627operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2628
2629<h5>Arguments:</h5>
2630<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2631<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2632type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2633
2634<h5>Semantics:</h5>
2635<p>This instruction always performs an arithmetic shift right operation,
2636The most significant bits of the result will be filled with the sign bit
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2637of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
2638larger than the number of bits in <tt>op1</tt>, the result is undefined.
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2639</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2640
2641<h5>Example:</h5>
2642<pre>
2643 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2644 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2645 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2646 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2647 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2648</pre>
2649</div>
2650
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2651<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2652<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2653Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2654
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2655<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2656
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2657<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2658
2659<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2660 &lt;result&gt; = and &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2661</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2662
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2663<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2664
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2665<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2666its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2667
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2668<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2669
2670<p>The two arguments to the '<tt>and</tt>' instruction must be
2671<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2672values. Both arguments must have identical types.</p>
2673
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2674<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2675<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2676<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2677<div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2678<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2679 <tbody>
2680 <tr>
2681 <td>In0</td>
2682 <td>In1</td>
2683 <td>Out</td>
2684 </tr>
2685 <tr>
2686 <td>0</td>
2687 <td>0</td>
2688 <td>0</td>
2689 </tr>
2690 <tr>
2691 <td>0</td>
2692 <td>1</td>
2693 <td>0</td>
2694 </tr>
2695 <tr>
2696 <td>1</td>
2697 <td>0</td>
2698 <td>0</td>
2699 </tr>
2700 <tr>
2701 <td>1</td>
2702 <td>1</td>
2703 <td>1</td>
2704 </tr>
2705 </tbody>
2706</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2707</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2708<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2709<pre>
2710 &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2711 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2712 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2713</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2714</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2715<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2716<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2717<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2718<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2719<pre> &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2720</pre>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2721<h5>Overview:</h5>
2722<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2723or of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2724<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2725
2726<p>The two arguments to the '<tt>or</tt>' instruction must be
2727<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2728values. Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2729<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2730<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2731<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2732<div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2733<table border="1" cellspacing="0" cellpadding="4">
2734 <tbody>
2735 <tr>
2736 <td>In0</td>
2737 <td>In1</td>
2738 <td>Out</td>
2739 </tr>
2740 <tr>
2741 <td>0</td>
2742 <td>0</td>
2743 <td>0</td>
2744 </tr>
2745 <tr>
2746 <td>0</td>
2747 <td>1</td>
2748 <td>1</td>
2749 </tr>
2750 <tr>
2751 <td>1</td>
2752 <td>0</td>
2753 <td>1</td>
2754 </tr>
2755 <tr>
2756 <td>1</td>
2757 <td>1</td>
2758 <td>1</td>
2759 </tr>
2760 </tbody>
2761</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2762</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2763<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2764<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2765 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2766 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2767</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2768</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2769<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2770<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2771Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2772<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2773<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2774<pre> &lt;result&gt; = xor &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2775</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2776<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2777<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2778or of its two operands. The <tt>xor</tt> is used to implement the
2779"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2780<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2781<p>The two arguments to the '<tt>xor</tt>' instruction must be
2782<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2783values. Both arguments must have identical types.</p>
2784
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2785<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2786
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2787<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2788<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2789<div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2790<table border="1" cellspacing="0" cellpadding="4">
2791 <tbody>
2792 <tr>
2793 <td>In0</td>
2794 <td>In1</td>
2795 <td>Out</td>
2796 </tr>
2797 <tr>
2798 <td>0</td>
2799 <td>0</td>
2800 <td>0</td>
2801 </tr>
2802 <tr>
2803 <td>0</td>
2804 <td>1</td>
2805 <td>1</td>
2806 </tr>
2807 <tr>
2808 <td>1</td>
2809 <td>0</td>
2810 <td>1</td>
2811 </tr>
2812 <tr>
2813 <td>1</td>
2814 <td>1</td>
2815 <td>0</td>
2816 </tr>
2817 </tbody>
2818</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2819</div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2820<p> </p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2821<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2822<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2823 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2824 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2825 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2826</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2827</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2828
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2829<!-- ======================================================================= -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2830<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2831 <a name="vectorops">Vector Operations</a>
2832</div>
2833
2834<div class="doc_text">
2835
2836<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2837target-independent manner. These instructions cover the element-access and
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2838vector-specific operations needed to process vectors effectively. While LLVM
2839does directly support these vector operations, many sophisticated algorithms
2840will want to use target-specific intrinsics to take full advantage of a specific
2841target.</p>
2842
2843</div>
2844
2845<!-- _______________________________________________________________________ -->
2846<div class="doc_subsubsection">
2847 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
2848</div>
2849
2850<div class="doc_text">
2851
2852<h5>Syntax:</h5>
2853
2854<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2855 &lt;result&gt; = extractelement &lt;n x &lt;ty&gt;&gt; &lt;val&gt;, i32 &lt;idx&gt; <i>; yields &lt;ty&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2856</pre>
2857
2858<h5>Overview:</h5>
2859
2860<p>
2861The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2862element from a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2863</p>
2864
2865
2866<h5>Arguments:</h5>
2867
2868<p>
2869The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2870value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2871an index indicating the position from which to extract the element.
2872The index may be a variable.</p>
2873
2874<h5>Semantics:</h5>
2875
2876<p>
2877The result is a scalar of the same type as the element type of
2878<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
2879<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
2880results are undefined.
2881</p>
2882
2883<h5>Example:</h5>
2884
2885<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2886 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2887</pre>
2888</div>
2889
2890
2891<!-- _______________________________________________________________________ -->
2892<div class="doc_subsubsection">
2893 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
2894</div>
2895
2896<div class="doc_text">
2897
2898<h5>Syntax:</h5>
2899
2900<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]2901 &lt;result&gt; = insertelement &lt;n x &lt;ty&gt;&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, i32 &lt;idx&gt; <i>; yields &lt;n x &lt;ty&gt;&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2902</pre>
2903
2904<h5>Overview:</h5>
2905
2906<p>
2907The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2908element into a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2909</p>
2910
2911
2912<h5>Arguments:</h5>
2913
2914<p>
2915The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2916value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2917scalar value whose type must equal the element type of the first
2918operand. The third operand is an index indicating the position at
2919which to insert the value. The index may be a variable.</p>
2920
2921<h5>Semantics:</h5>
2922
2923<p>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2924The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2925element values are those of <tt>val</tt> except at position
2926<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
2927exceeds the length of <tt>val</tt>, the results are undefined.
2928</p>
2929
2930<h5>Example:</h5>
2931
2932<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2933 %result = insertelement &lt;4 x i32&gt; %vec, i32 1, i32 0 <i>; yields &lt;4 x i32&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2934</pre>
2935</div>
2936
2937<!-- _______________________________________________________________________ -->
2938<div class="doc_subsubsection">
2939 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
2940</div>
2941
2942<div class="doc_text">
2943
2944<h5>Syntax:</h5>
2945
2946<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]2947 &lt;result&gt; = shufflevector &lt;n x &lt;ty&gt;&gt; &lt;v1&gt;, &lt;n x &lt;ty&gt;&gt; &lt;v2&gt;, &lt;m x i32&gt; &lt;mask&gt; <i>; yields &lt;m x &lt;ty&gt;&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2948</pre>
2949
2950<h5>Overview:</h5>
2951
2952<p>
2953The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]2954from two input vectors, returning a vector with the same element type as
2955the input and length that is the same as the shuffle mask.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2956</p>
2957
2958<h5>Arguments:</h5>
2959
2960<p>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]2961The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
2962with types that match each other. The third argument is a shuffle mask whose
2963element type is always 'i32'. The result of the instruction is a vector whose
2964length is the same as the shuffle mask and whose element type is the same as
2965the element type of the first two operands.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2966</p>
2967
2968<p>
2969The shuffle mask operand is required to be a constant vector with either
2970constant integer or undef values.
2971</p>
2972
2973<h5>Semantics:</h5>
2974
2975<p>
2976The elements of the two input vectors are numbered from left to right across
2977both of the vectors. The shuffle mask operand specifies, for each element of
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]2978the result vector, which element of the two input vectors the result element
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2979gets. The element selector may be undef (meaning "don't care") and the second
2980operand may be undef if performing a shuffle from only one vector.
2981</p>
2982
2983<h5>Example:</h5>
2984
2985<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2986 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2987 &lt;4 x i32&gt; &lt;i32 0, i32 4, i32 1, i32 5&gt; <i>; yields &lt;4 x i32&gt;</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2988 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
2989 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i> - Identity shuffle.
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]2990 %result = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
2991 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
2992 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
2993 &lt;8 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7 &gt; <i>; yields &lt;8 x i32&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2994</pre>
2995</div>
2996
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]2997
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2998<!-- ======================================================================= -->
2999<div class="doc_subsection">
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3000 <a name="aggregateops">Aggregate Operations</a>
3001</div>
3002
3003<div class="doc_text">
3004
3005<p>LLVM supports several instructions for working with aggregate values.
3006</p>
3007
3008</div>
3009
3010<!-- _______________________________________________________________________ -->
3011<div class="doc_subsubsection">
3012 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3013</div>
3014
3015<div class="doc_text">
3016
3017<h5>Syntax:</h5>
3018
3019<pre>
3020 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3021</pre>
3022
3023<h5>Overview:</h5>
3024
3025<p>
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3026The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3027or array element from an aggregate value.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3028</p>
3029
3030
3031<h5>Arguments:</h5>
3032
3033<p>
3034The first operand of an '<tt>extractvalue</tt>' instruction is a
3035value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3036type. The operands are constant indices to specify which value to extract
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3037in a similar manner as indices in a
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3038'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3039</p>
3040
3041<h5>Semantics:</h5>
3042
3043<p>
3044The result is the value at the position in the aggregate specified by
3045the index operands.
3046</p>
3047
3048<h5>Example:</h5>
3049
3050<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3051 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3052</pre>
3053</div>
3054
3055
3056<!-- _______________________________________________________________________ -->
3057<div class="doc_subsubsection">
3058 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3059</div>
3060
3061<div class="doc_text">
3062
3063<h5>Syntax:</h5>
3064
3065<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3066 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;val&gt;, &lt;idx&gt; <i>; yields &lt;n x &lt;ty&gt;&gt;</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3067</pre>
3068
3069<h5>Overview:</h5>
3070
3071<p>
3072The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3073into a struct field or array element in an aggregate.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3074</p>
3075
3076
3077<h5>Arguments:</h5>
3078
3079<p>
3080The first operand of an '<tt>insertvalue</tt>' instruction is a
3081value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
3082The second operand is a first-class value to insert.
Dan Gohmanc4b49eb2008-05-23 21:53:15 +0000[diff] [blame]3083The following operands are constant indices
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3084indicating the position at which to insert the value in a similar manner as
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3085indices in a
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3086'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3087The value to insert must have the same type as the value identified
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3088by the indices.
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3089</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3090
3091<h5>Semantics:</h5>
3092
3093<p>
3094The result is an aggregate of the same type as <tt>val</tt>. Its
3095value is that of <tt>val</tt> except that the value at the position
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3096specified by the indices is that of <tt>elt</tt>.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3097</p>
3098
3099<h5>Example:</h5>
3100
3101<pre>
Dan Gohman52bb2db2008-06-23 15:26:37 +0000[diff] [blame]3102 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3103</pre>
3104</div>
3105
3106
3107<!-- ======================================================================= -->
3108<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3109 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3110</div>
3111
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3112<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3113
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3114<p>A key design point of an SSA-based representation is how it
3115represents memory. In LLVM, no memory locations are in SSA form, which
3116makes things very simple. This section describes how to read, write,
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3117allocate, and free memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3118
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3119</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3120
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3121<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3122<div class="doc_subsubsection">
3123 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3124</div>
3125
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3126<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3127
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3128<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3129
3130<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3131 &lt;result&gt; = malloc &lt;type&gt;[, i32 &lt;NumElements&gt;][, align &lt;alignment&gt;] <i>; yields {type*}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3132</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3133
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3134<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3135
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3136<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]3137heap and returns a pointer to it. The object is always allocated in the generic
3138address space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3139
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3140<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3141
3142<p>The '<tt>malloc</tt>' instruction allocates
3143<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswell6e4ca612004-02-24 16:13:56 +0000[diff] [blame]3144bytes of memory from the operating system and returns a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3145appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3146number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3147If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3148be aligned to at least that boundary. If not specified, or if zero, the target can
3149choose to align the allocation on any convenient boundary.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3150
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3151<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3152
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3153<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3154
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3155<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3156a pointer is returned. The result of a zero byte allocattion is undefined. The
3157result is null if there is insufficient memory available.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3158
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3159<h5>Example:</h5>
3160
3161<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3162 %array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3163
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3164 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3165 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3166 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3167 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3168 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3169</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3170</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3171
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3172<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3173<div class="doc_subsubsection">
3174 <a name="i_free">'<tt>free</tt>' Instruction</a>
3175</div>
3176
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3177<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3178
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3179<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3180
3181<pre>
3182 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3183</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3184
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3185<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3186
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3187<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]3188memory heap to be reallocated in the future.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3189
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3190<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3191
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3192<p>'<tt>value</tt>' shall be a pointer value that points to a value
3193that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
3194instruction.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3195
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3196<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3197
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3198<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattnere0db56d2008-04-19 22:41:32 +0000[diff] [blame]3199after this instruction executes. If the pointer is null, the operation
3200is a noop.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3201
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3202<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3203
3204<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3205 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
3206 free [4 x i8]* %array
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3207</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3208</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3209
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3210<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3211<div class="doc_subsubsection">
3212 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3213</div>
3214
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3215<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3216
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3217<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3218
3219<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3220 &lt;result&gt; = alloca &lt;type&gt;[, i32 &lt;NumElements&gt;][, align &lt;alignment&gt;] <i>; yields {type*}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3221</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3222
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3223<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3224
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3225<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
3226currently executing function, to be automatically released when this function
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]3227returns to its caller. The object is always allocated in the generic address
3228space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3229
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3230<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3231
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3232<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3233bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3234appropriate type to the program. If "NumElements" is specified, it is the
3235number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3236If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3237to be aligned to at least that boundary. If not specified, or if zero, the target
3238can choose to align the allocation on any convenient boundary.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3239
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3240<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3241
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3242<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3243
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3244<p>Memory is allocated; a pointer is returned. The operation is undefiend if
3245there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3246memory is automatically released when the function returns. The '<tt>alloca</tt>'
3247instruction is commonly used to represent automatic variables that must
3248have an address available. When the function returns (either with the <tt><a
John Criswelldae2e932005-05-12 16:55:34 +0000[diff] [blame]3249 href="#i_ret">ret</a></tt> or <tt><a href="#i_unwind">unwind</a></tt>
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3250instructions), the memory is reclaimed. Allocating zero bytes
3251is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3252
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3253<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3254
3255<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3256 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3257 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3258 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3259 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3260</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3261</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3262
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3263<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3264<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3265Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3266<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3267<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]3268<pre> &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]<br> &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]<br></pre>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3269<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3270<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3271<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3272<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]3273address from which to load. The pointer must point to a <a
Chris Lattnere53e5082004-06-03 22:57:15 +0000[diff] [blame]3274 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]3275marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3276the number or order of execution of this <tt>load</tt> with other
3277volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3278instructions. </p>
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3279<p>
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3280The optional constant "align" argument specifies the alignment of the operation
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3281(that is, the alignment of the memory address). A value of 0 or an
3282omitted "align" argument means that the operation has the preferential
3283alignment for the target. It is the responsibility of the code emitter
3284to ensure that the alignment information is correct. Overestimating
3285the alignment results in an undefined behavior. Underestimating the
3286alignment may produce less efficient code. An alignment of 1 is always
3287safe.
3288</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3289<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3290<p>The location of memory pointed to is loaded.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3291<h5>Examples:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3292<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3293 <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3294 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
3295 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3296</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3297</div>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3298<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3299<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3300Instruction</a> </div>
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]3301<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3302<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]3303<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
3304 volatile store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3305</pre>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3306<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3307<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3308<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3309<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3310to store and an address at which to store it. The type of the '<tt>&lt;pointer&gt;</tt>'
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3311operand must be a pointer to the <a href="#t_firstclass">first class</a> type
3312of the '<tt>&lt;value&gt;</tt>'
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]3313operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3314optimizer is not allowed to modify the number or order of execution of
3315this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
3316 href="#i_store">store</a></tt> instructions.</p>
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3317<p>
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3318The optional constant "align" argument specifies the alignment of the operation
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3319(that is, the alignment of the memory address). A value of 0 or an
3320omitted "align" argument means that the operation has the preferential
3321alignment for the target. It is the responsibility of the code emitter
3322to ensure that the alignment information is correct. Overestimating
3323the alignment results in an undefined behavior. Underestimating the
3324alignment may produce less efficient code. An alignment of 1 is always
3325safe.
3326</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3327<h5>Semantics:</h5>
3328<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
3329at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3330<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3331<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]3332 store i32 3, i32* %ptr <i>; yields {void}</i>
3333 %val = <a href="#i_load">load</a> i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3334</pre>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3335</div>
3336
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3337<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3338<div class="doc_subsubsection">
3339 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3340</div>
3341
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3342<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3343<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3344<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3345 &lt;result&gt; = getelementptr &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3346</pre>
3347
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3348<h5>Overview:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3349
3350<p>
3351The '<tt>getelementptr</tt>' instruction is used to get the address of a
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3352subelement of an aggregate data structure. It performs address calculation only
3353and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3354
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3355<h5>Arguments:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3356
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3357<p>The first argument is always a pointer, and forms the basis of the
3358calculation. The remaining arguments are indices, that indicate which of the
3359elements of the aggregate object are indexed. The interpretation of each index
3360is dependent on the type being indexed into. The first index always indexes the
3361pointer value given as the first argument, the second index indexes a value of
3362the type pointed to (not necessarily the value directly pointed to, since the
3363first index can be non-zero), etc. The first type indexed into must be a pointer
3364value, subsequent types can be arrays, vectors and structs. Note that subsequent
3365types being indexed into can never be pointers, since that would require loading
3366the pointer before continuing calculation.</p>
3367
3368<p>The type of each index argument depends on the type it is indexing into.
3369When indexing into a (packed) structure, only <tt>i32</tt> integer
3370<b>constants</b> are allowed. When indexing into an array, pointer or vector,
3371only integers of 32 or 64 bits are allowed (also non-constants). 32-bit values
3372will be sign extended to 64-bits if required.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3373
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3374<p>For example, let's consider a C code fragment and how it gets
3375compiled to LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3376
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3377<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3378<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3379struct RT {
3380 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3381 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3382 char C;
3383};
3384struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3385 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3386 double Y;
3387 struct RT Z;
3388};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3389
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3390int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3391 return &amp;s[1].Z.B[5][13];
3392}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3393</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3394</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3395
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3396<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3397
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3398<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3399<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3400%RT = type { i8 , [10 x [20 x i32]], i8 }
3401%ST = type { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3402
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3403define i32* %foo(%ST* %s) {
3404entry:
3405 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3406 ret i32* %reg
3407}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3408</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3409</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3410
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3411<h5>Semantics:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3412
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3413<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3414type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3415}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3416the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3417i8 }</tt>' type, another structure. The third index indexes into the second
3418element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3419array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3420'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
3421to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3422
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3423<p>Note that it is perfectly legal to index partially through a
3424structure, returning a pointer to an inner element. Because of this,
3425the LLVM code for the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3426
3427<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3428 define i32* %foo(%ST* %s) {
3429 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3430 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3431 %t3 = getelementptr %RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3432 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3433 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
3434 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3435 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3436</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3437
3438<p>Note that it is undefined to access an array out of bounds: array and
3439pointer indexes must always be within the defined bounds of the array type.
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]3440The one exception for this rule is zero length arrays. These arrays are
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3441defined to be accessible as variable length arrays, which requires access
3442beyond the zero'th element.</p>
3443
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3444<p>The getelementptr instruction is often confusing. For some more insight
3445into how it works, see <a href="GetElementPtr.html">the getelementptr
3446FAQ</a>.</p>
3447
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3448<h5>Example:</h5>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3449
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3450<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3451 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3452 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
3453 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3454 %vptr = getelementptr {i32, &lt;2 x i8&gt;}* %svptr, i64 0, i32 1, i32 1
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3455 <i>; yields i8*:eptr</i>
3456 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3457</pre>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3458</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3459
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3460<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3461<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3462</div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3463<div class="doc_text">
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3464<p>The instructions in this category are the conversion instructions (casting)
3465which all take a single operand and a type. They perform various bit conversions
3466on the operand.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3467</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3468
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3469<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3470<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3471 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
3472</div>
3473<div class="doc_text">
3474
3475<h5>Syntax:</h5>
3476<pre>
3477 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3478</pre>
3479
3480<h5>Overview:</h5>
3481<p>
3482The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
3483</p>
3484
3485<h5>Arguments:</h5>
3486<p>
3487The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
3488be an <a href="#t_integer">integer</a> type, and a type that specifies the size
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3489and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3490type. The bit size of <tt>value</tt> must be larger than the bit size of
3491<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3492
3493<h5>Semantics:</h5>
3494<p>
3495The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3496and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
3497larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
3498It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3499
3500<h5>Example:</h5>
3501<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3502 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3503 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
3504 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3505</pre>
3506</div>
3507
3508<!-- _______________________________________________________________________ -->
3509<div class="doc_subsubsection">
3510 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
3511</div>
3512<div class="doc_text">
3513
3514<h5>Syntax:</h5>
3515<pre>
3516 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3517</pre>
3518
3519<h5>Overview:</h5>
3520<p>The '<tt>zext</tt>' instruction zero extends its operand to type
3521<tt>ty2</tt>.</p>
3522
3523
3524<h5>Arguments:</h5>
3525<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3526<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3527also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3528<tt>value</tt> must be smaller than the bit size of the destination type,
3529<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3530
3531<h5>Semantics:</h5>
3532<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Chris Lattnerd1d25172007-05-24 19:13:27 +0000[diff] [blame]3533bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3534
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]3535<p>When zero extending from i1, the result will always be either 0 or 1.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3536
3537<h5>Example:</h5>
3538<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3539 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3540 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3541</pre>
3542</div>
3543
3544<!-- _______________________________________________________________________ -->
3545<div class="doc_subsubsection">
3546 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3547</div>
3548<div class="doc_text">
3549
3550<h5>Syntax:</h5>
3551<pre>
3552 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3553</pre>
3554
3555<h5>Overview:</h5>
3556<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3557
3558<h5>Arguments:</h5>
3559<p>
3560The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3561<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3562also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3563<tt>value</tt> must be smaller than the bit size of the destination type,
3564<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3565
3566<h5>Semantics:</h5>
3567<p>
3568The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3569bit (highest order bit) of the <tt>value</tt> until it reaches the bit size of
Chris Lattnerd1d25172007-05-24 19:13:27 +0000[diff] [blame]3570the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3571
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3572<p>When sign extending from i1, the extension always results in -1 or 0.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3573
3574<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3575<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3576 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3577 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3578</pre>
3579</div>
3580
3581<!-- _______________________________________________________________________ -->
3582<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3583 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3584</div>
3585
3586<div class="doc_text">
3587
3588<h5>Syntax:</h5>
3589
3590<pre>
3591 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3592</pre>
3593
3594<h5>Overview:</h5>
3595<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3596<tt>ty2</tt>.</p>
3597
3598
3599<h5>Arguments:</h5>
3600<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3601 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3602cast it to. The size of <tt>value</tt> must be larger than the size of
3603<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3604<i>no-op cast</i>.</p>
3605
3606<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3607<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3608<a href="#t_floating">floating point</a> type to a smaller
3609<a href="#t_floating">floating point</a> type. If the value cannot fit within
3610the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3611
3612<h5>Example:</h5>
3613<pre>
3614 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3615 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3616</pre>
3617</div>
3618
3619<!-- _______________________________________________________________________ -->
3620<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3621 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3622</div>
3623<div class="doc_text">
3624
3625<h5>Syntax:</h5>
3626<pre>
3627 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3628</pre>
3629
3630<h5>Overview:</h5>
3631<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3632floating point value.</p>
3633
3634<h5>Arguments:</h5>
3635<p>The '<tt>fpext</tt>' instruction takes a
3636<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3637and a <a href="#t_floating">floating point</a> type to cast it to. The source
3638type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3639
3640<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3641<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3642<a href="#t_floating">floating point</a> type to a larger
3643<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3644used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3645<tt>bitcast</tt> to make a <i>no-op cast</i> for a floating point cast.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3646
3647<h5>Example:</h5>
3648<pre>
3649 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3650 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3651</pre>
3652</div>
3653
3654<!-- _______________________________________________________________________ -->
3655<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]3656 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3657</div>
3658<div class="doc_text">
3659
3660<h5>Syntax:</h5>
3661<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3662 &lt;result&gt; = fptoui &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3663</pre>
3664
3665<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3666<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3667unsigned integer equivalent of type <tt>ty2</tt>.
3668</p>
3669
3670<h5>Arguments:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3671<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3672scalar or vector <a href="#t_floating">floating point</a> value, and a type
3673to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3674type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3675vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3676
3677<h5>Semantics:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3678<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3679<a href="#t_floating">floating point</a> operand into the nearest (rounding
3680towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3681the results are undefined.</p>
3682
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3683<h5>Example:</h5>
3684<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3685 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3686 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3687 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3688</pre>
3689</div>
3690
3691<!-- _______________________________________________________________________ -->
3692<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3693 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3694</div>
3695<div class="doc_text">
3696
3697<h5>Syntax:</h5>
3698<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3699 &lt;result&gt; = fptosi &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3700</pre>
3701
3702<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3703<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3704<a href="#t_floating">floating point</a> <tt>value</tt> to type <tt>ty2</tt>.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3705</p>
3706
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3707<h5>Arguments:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3708<p> The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3709scalar or vector <a href="#t_floating">floating point</a> value, and a type
3710to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3711type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3712vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3713
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3714<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3715<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3716<a href="#t_floating">floating point</a> operand into the nearest (rounding
3717towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3718the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3719
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3720<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3721<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3722 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3723 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3724 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3725</pre>
3726</div>
3727
3728<!-- _______________________________________________________________________ -->
3729<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3730 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3731</div>
3732<div class="doc_text">
3733
3734<h5>Syntax:</h5>
3735<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3736 &lt;result&gt; = uitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3737</pre>
3738
3739<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3740<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3741integer and converts that value to the <tt>ty2</tt> type.</p>
3742
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3743<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3744<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3745scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3746to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3747type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3748floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3749
3750<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3751<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3752integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3753the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3754
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3755<h5>Example:</h5>
3756<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3757 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3758 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3759</pre>
3760</div>
3761
3762<!-- _______________________________________________________________________ -->
3763<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3764 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3765</div>
3766<div class="doc_text">
3767
3768<h5>Syntax:</h5>
3769<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3770 &lt;result&gt; = sitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3771</pre>
3772
3773<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3774<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3775integer and converts that value to the <tt>ty2</tt> type.</p>
3776
3777<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3778<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3779scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3780to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3781type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3782floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3783
3784<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3785<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3786integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3787the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3788
3789<h5>Example:</h5>
3790<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3791 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3792 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3793</pre>
3794</div>
3795
3796<!-- _______________________________________________________________________ -->
3797<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3798 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3799</div>
3800<div class="doc_text">
3801
3802<h5>Syntax:</h5>
3803<pre>
3804 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3805</pre>
3806
3807<h5>Overview:</h5>
3808<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3809the integer type <tt>ty2</tt>.</p>
3810
3811<h5>Arguments:</h5>
3812<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3813must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3814<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3815
3816<h5>Semantics:</h5>
3817<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3818<tt>ty2</tt> by interpreting the pointer value as an integer and either
3819truncating or zero extending that value to the size of the integer type. If
3820<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3821<tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3822are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3823change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3824
3825<h5>Example:</h5>
3826<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3827 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3828 %Y = ptrtoint i32* %x to i64 <i>; yields zero extension on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3829</pre>
3830</div>
3831
3832<!-- _______________________________________________________________________ -->
3833<div class="doc_subsubsection">
3834 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3835</div>
3836<div class="doc_text">
3837
3838<h5>Syntax:</h5>
3839<pre>
3840 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3841</pre>
3842
3843<h5>Overview:</h5>
3844<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
3845a pointer type, <tt>ty2</tt>.</p>
3846
3847<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3848<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3849value to cast, and a type to cast it to, which must be a
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3850<a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3851
3852<h5>Semantics:</h5>
3853<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
3854<tt>ty2</tt> by applying either a zero extension or a truncation depending on
3855the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
3856size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
3857the size of a pointer then a zero extension is done. If they are the same size,
3858nothing is done (<i>no-op cast</i>).</p>
3859
3860<h5>Example:</h5>
3861<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3862 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
3863 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
3864 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3865</pre>
3866</div>
3867
3868<!-- _______________________________________________________________________ -->
3869<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3870 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3871</div>
3872<div class="doc_text">
3873
3874<h5>Syntax:</h5>
3875<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3876 &lt;result&gt; = bitcast &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3877</pre>
3878
3879<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3880
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3881<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3882<tt>ty2</tt> without changing any bits.</p>
3883
3884<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3885
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3886<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Dan Gohman500233a2008-09-08 16:45:59 +0000[diff] [blame]3887a non-aggregate first class value, and a type to cast it to, which must also be
3888a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
3889<tt>value</tt>
Reid Spencer19b569f2007-01-09 20:08:58 +0000[diff] [blame]3890and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3891type is a pointer, the destination type must also be a pointer. This
3892instruction supports bitwise conversion of vectors to integers and to vectors
3893of other types (as long as they have the same size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3894
3895<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3896<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3897<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
3898this conversion. The conversion is done as if the <tt>value</tt> had been
3899stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
3900converted to other pointer types with this instruction. To convert pointers to
3901other types, use the <a href="#i_inttoptr">inttoptr</a> or
3902<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3903
3904<h5>Example:</h5>
3905<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3906 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3907 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3908 %Z = bitcast &lt;2 x int&gt; %V to i64; <i>; yields i64: %V</i>
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3909</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3910</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3911
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3912<!-- ======================================================================= -->
3913<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
3914<div class="doc_text">
3915<p>The instructions in this category are the "miscellaneous"
3916instructions, which defy better classification.</p>
3917</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3918
3919<!-- _______________________________________________________________________ -->
3920<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
3921</div>
3922<div class="doc_text">
3923<h5>Syntax:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3924<pre> &lt;result&gt; = icmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt;}:result</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3925</pre>
3926<h5>Overview:</h5>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]3927<p>The '<tt>icmp</tt>' instruction returns a boolean value or
3928a vector of boolean values based on comparison
3929of its two integer, integer vector, or pointer operands.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3930<h5>Arguments:</h5>
3931<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3932the condition code indicating the kind of comparison to perform. It is not
3933a value, just a keyword. The possible condition code are:
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3934</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3935<ol>
3936 <li><tt>eq</tt>: equal</li>
3937 <li><tt>ne</tt>: not equal </li>
3938 <li><tt>ugt</tt>: unsigned greater than</li>
3939 <li><tt>uge</tt>: unsigned greater or equal</li>
3940 <li><tt>ult</tt>: unsigned less than</li>
3941 <li><tt>ule</tt>: unsigned less or equal</li>
3942 <li><tt>sgt</tt>: signed greater than</li>
3943 <li><tt>sge</tt>: signed greater or equal</li>
3944 <li><tt>slt</tt>: signed less than</li>
3945 <li><tt>sle</tt>: signed less or equal</li>
3946</ol>
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3947<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]3948<a href="#t_pointer">pointer</a>
3949or integer <a href="#t_vector">vector</a> typed.
3950They must also be identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3951<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3952<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3953the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]3954yields either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt> result, as follows:
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3955</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3956<ol>
3957 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
3958 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3959 </li>
3960 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3961 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3962 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3963 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3964 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3965 <tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3966 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3967 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3968 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3969 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3970 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3971 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3972 <li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3973 <tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3974 <li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3975 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3976 <li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3977 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3978</ol>
3979<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3980values are compared as if they were integers.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]3981<p>If the operands are integer vectors, then they are compared
3982element by element. The result is an <tt>i1</tt> vector with
3983the same number of elements as the values being compared.
3984Otherwise, the result is an <tt>i1</tt>.
3985</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3986
3987<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3988<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
3989 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
3990 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
3991 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
3992 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
3993 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3994</pre>
3995</div>
3996
3997<!-- _______________________________________________________________________ -->
3998<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
3999</div>
4000<div class="doc_text">
4001<h5>Syntax:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4002<pre> &lt;result&gt; = fcmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt;}:result</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4003</pre>
4004<h5>Overview:</h5>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4005<p>The '<tt>fcmp</tt>' instruction returns a boolean value
4006or vector of boolean values based on comparison
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4007of its operands.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4008<p>
4009If the operands are floating point scalars, then the result
4010type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
4011</p>
4012<p>If the operands are floating point vectors, then the result type
4013is a vector of boolean with the same number of elements as the
4014operands being compared.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4015<h5>Arguments:</h5>
4016<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4017the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4018a value, just a keyword. The possible condition code are:</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4019<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4020 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4021 <li><tt>oeq</tt>: ordered and equal</li>
4022 <li><tt>ogt</tt>: ordered and greater than </li>
4023 <li><tt>oge</tt>: ordered and greater than or equal</li>
4024 <li><tt>olt</tt>: ordered and less than </li>
4025 <li><tt>ole</tt>: ordered and less than or equal</li>
4026 <li><tt>one</tt>: ordered and not equal</li>
4027 <li><tt>ord</tt>: ordered (no nans)</li>
4028 <li><tt>ueq</tt>: unordered or equal</li>
4029 <li><tt>ugt</tt>: unordered or greater than </li>
4030 <li><tt>uge</tt>: unordered or greater than or equal</li>
4031 <li><tt>ult</tt>: unordered or less than </li>
4032 <li><tt>ule</tt>: unordered or less than or equal</li>
4033 <li><tt>une</tt>: unordered or not equal</li>
4034 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4035 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4036</ol>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4037<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer93a49852006-12-06 07:08:07 +0000[diff] [blame]4038<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4039<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
4040either a <a href="#t_floating">floating point</a> type
4041or a <a href="#t_vector">vector</a> of floating point type.
4042They must have identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4043<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4044<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4045according to the condition code given as <tt>cond</tt>.
4046If the operands are vectors, then the vectors are compared
4047element by element.
4048Each comparison performed
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4049always yields an <a href="#t_primitive">i1</a> result, as follows:</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4050<ol>
4051 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4052 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4053 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4054 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4055 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4056 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4057 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4058 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4059 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4060 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4061 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4062 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4063 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4064 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
4065 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4066 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4067 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4068 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4069 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4070 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4071 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4072 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4073 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4074 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4075 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4076 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4077 <li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4078 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4079</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4080
4081<h5>Example:</h5>
4082<pre> &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4083 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4084 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4085 &lt;result&gt; = fcmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4086</pre>
4087</div>
4088
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4089<!-- _______________________________________________________________________ -->
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4090<div class="doc_subsubsection">
4091 <a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
4092</div>
4093<div class="doc_text">
4094<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4095<pre> &lt;result&gt; = vicmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4096</pre>
4097<h5>Overview:</h5>
4098<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
4099element-wise comparison of its two integer vector operands.</p>
4100<h5>Arguments:</h5>
4101<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
4102the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4103a value, just a keyword. The possible condition code are:</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4104<ol>
4105 <li><tt>eq</tt>: equal</li>
4106 <li><tt>ne</tt>: not equal </li>
4107 <li><tt>ugt</tt>: unsigned greater than</li>
4108 <li><tt>uge</tt>: unsigned greater or equal</li>
4109 <li><tt>ult</tt>: unsigned less than</li>
4110 <li><tt>ule</tt>: unsigned less or equal</li>
4111 <li><tt>sgt</tt>: signed greater than</li>
4112 <li><tt>sge</tt>: signed greater or equal</li>
4113 <li><tt>slt</tt>: signed less than</li>
4114 <li><tt>sle</tt>: signed less or equal</li>
4115</ol>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4116<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4117<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
4118<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4119<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4120according to the condition code given as <tt>cond</tt>. The comparison yields a
4121<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
4122identical type as the values being compared. The most significant bit in each
4123element is 1 if the element-wise comparison evaluates to true, and is 0
4124otherwise. All other bits of the result are undefined. The condition codes
4125are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4126instruction</a>.</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4127
4128<h5>Example:</h5>
4129<pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4130 &lt;result&gt; = vicmp eq &lt;2 x i32&gt; &lt; i32 4, i32 0&gt;, &lt; i32 5, i32 0&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0, i32 -1 &gt;</i>
4131 &lt;result&gt; = vicmp ult &lt;2 x i8 &gt; &lt; i8 1, i8 2&gt;, &lt; i8 2, i8 2 &gt; <i>; yields: result=&lt;2 x i8&gt; &lt; i8 -1, i8 0 &gt;</i>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4132</pre>
4133</div>
4134
4135<!-- _______________________________________________________________________ -->
4136<div class="doc_subsubsection">
4137 <a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
4138</div>
4139<div class="doc_text">
4140<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4141<pre> &lt;result&gt; = vfcmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt;</pre>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4142<h5>Overview:</h5>
4143<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
4144element-wise comparison of its two floating point vector operands. The output
4145elements have the same width as the input elements.</p>
4146<h5>Arguments:</h5>
4147<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
4148the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4149a value, just a keyword. The possible condition code are:</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4150<ol>
4151 <li><tt>false</tt>: no comparison, always returns false</li>
4152 <li><tt>oeq</tt>: ordered and equal</li>
4153 <li><tt>ogt</tt>: ordered and greater than </li>
4154 <li><tt>oge</tt>: ordered and greater than or equal</li>
4155 <li><tt>olt</tt>: ordered and less than </li>
4156 <li><tt>ole</tt>: ordered and less than or equal</li>
4157 <li><tt>one</tt>: ordered and not equal</li>
4158 <li><tt>ord</tt>: ordered (no nans)</li>
4159 <li><tt>ueq</tt>: unordered or equal</li>
4160 <li><tt>ugt</tt>: unordered or greater than </li>
4161 <li><tt>uge</tt>: unordered or greater than or equal</li>
4162 <li><tt>ult</tt>: unordered or less than </li>
4163 <li><tt>ule</tt>: unordered or less than or equal</li>
4164 <li><tt>une</tt>: unordered or not equal</li>
4165 <li><tt>uno</tt>: unordered (either nans)</li>
4166 <li><tt>true</tt>: no comparison, always returns true</li>
4167</ol>
4168<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
4169<a href="#t_floating">floating point</a> typed. They must also be identical
4170types.</p>
4171<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4172<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4173according to the condition code given as <tt>cond</tt>. The comparison yields a
4174<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
4175an identical number of elements as the values being compared, and each element
4176having identical with to the width of the floating point elements. The most
4177significant bit in each element is 1 if the element-wise comparison evaluates to
4178true, and is 0 otherwise. All other bits of the result are undefined. The
4179condition codes are evaluated identically to the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4180<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4181
4182<h5>Example:</h5>
4183<pre>
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]4184 <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0, i32 -1 &gt;</i>
4185 &lt;result&gt; = vfcmp oeq &lt;2 x float&gt; &lt; float 4, float 0 &gt;, &lt; float 5, float 0 &gt;
4186
4187 <i>; yields: result=&lt;2 x i64&gt; &lt; i64 -1, i64 0 &gt;</i>
4188 &lt;result&gt; = vfcmp ult &lt;2 x double&gt; &lt; double 1, double 2 &gt;, &lt; double 2, double 2&gt;
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4189</pre>
4190</div>
4191
4192<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4193<div class="doc_subsubsection">
4194 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4195</div>
4196
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4197<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4198
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4199<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4200
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4201<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
4202<h5>Overview:</h5>
4203<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
4204the SSA graph representing the function.</p>
4205<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4206
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4207<p>The type of the incoming values is specified with the first type
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4208field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
4209as arguments, with one pair for each predecessor basic block of the
4210current block. Only values of <a href="#t_firstclass">first class</a>
4211type may be used as the value arguments to the PHI node. Only labels
4212may be used as the label arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4213
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4214<p>There must be no non-phi instructions between the start of a basic
4215block and the PHI instructions: i.e. PHI instructions must be first in
4216a basic block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4217
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4218<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4219
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4220<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
4221specified by the pair corresponding to the predecessor basic block that executed
4222just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4223
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4224<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4225<pre>
4226Loop: ; Infinite loop that counts from 0 on up...
4227 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4228 %nextindvar = add i32 %indvar, 1
4229 br label %Loop
4230</pre>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4231</div>
4232
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4233<!-- _______________________________________________________________________ -->
4234<div class="doc_subsubsection">
4235 <a name="i_select">'<tt>select</tt>' Instruction</a>
4236</div>
4237
4238<div class="doc_text">
4239
4240<h5>Syntax:</h5>
4241
4242<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4243 &lt;result&gt; = select <i>selty</i> &lt;cond&gt;, &lt;ty&gt; &lt;val1&gt;, &lt;ty&gt; &lt;val2&gt; <i>; yields ty</i>
4244
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4245 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4246</pre>
4247
4248<h5>Overview:</h5>
4249
4250<p>
4251The '<tt>select</tt>' instruction is used to choose one value based on a
4252condition, without branching.
4253</p>
4254
4255
4256<h5>Arguments:</h5>
4257
4258<p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4259The '<tt>select</tt>' instruction requires an 'i1' value or
4260a vector of 'i1' values indicating the
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4261condition, and two values of the same <a href="#t_firstclass">first class</a>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4262type. If the val1/val2 are vectors and
4263the condition is a scalar, then entire vectors are selected, not
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4264individual elements.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4265</p>
4266
4267<h5>Semantics:</h5>
4268
4269<p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4270If the condition is an i1 and it evaluates to 1, the instruction returns the first
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4271value argument; otherwise, it returns the second value argument.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4272</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4273<p>
4274If the condition is a vector of i1, then the value arguments must
4275be vectors of the same size, and the selection is done element
4276by element.
4277</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4278
4279<h5>Example:</h5>
4280
4281<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4282 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4283</pre>
4284</div>
4285
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]4286
4287<!-- _______________________________________________________________________ -->
4288<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4289 <a name="i_call">'<tt>call</tt>' Instruction</a>
4290</div>
4291
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4292<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4293
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4294<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4295<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]4296 &lt;result&gt; = [tail] call [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] &lt;ty&gt; [&lt;fnty&gt;*] &lt;fnptrval&gt;(&lt;function args&gt;) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4297</pre>
4298
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4299<h5>Overview:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4300
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4301<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4302
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4303<h5>Arguments:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4304
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4305<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4306
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4307<ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4308 <li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4309 <p>The optional "tail" marker indicates whether the callee function accesses
4310 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4311 function call is eligible for tail call optimization. Note that calls may
4312 be marked "tail" even if they do not occur before a <a
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4313 href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4314 </li>
4315 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4316 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4317 convention</a> the call should use. If none is specified, the call defaults
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4318 to using C calling conventions.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4319 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4320
4321 <li>
4322 <p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4323 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
4324 and '<tt>inreg</tt>' attributes are valid here.</p>
4325 </li>
4326
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4327 <li>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4328 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
4329 the type of the return value. Functions that return no value are marked
4330 <tt><a href="#t_void">void</a></tt>.</p>
4331 </li>
4332 <li>
4333 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
4334 value being invoked. The argument types must match the types implied by
4335 this signature. This type can be omitted if the function is not varargs
4336 and if the function type does not return a pointer to a function.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4337 </li>
4338 <li>
4339 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4340 be invoked. In most cases, this is a direct function invocation, but
4341 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4342 to function value.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4343 </li>
4344 <li>
4345 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencera7e302a2005-05-01 22:22:57 +0000[diff] [blame]4346 function signature argument types. All arguments must be of
4347 <a href="#t_firstclass">first class</a> type. If the function signature
4348 indicates the function accepts a variable number of arguments, the extra
4349 arguments can be specified.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4350 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4351 <li>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]4352 <p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4353 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
4354 '<tt>readnone</tt>' attributes are valid here.</p>
4355 </li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4356</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4357
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4358<h5>Semantics:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4359
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4360<p>The '<tt>call</tt>' instruction is used to cause control flow to
4361transfer to a specified function, with its incoming arguments bound to
4362the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
4363instruction in the called function, control flow continues with the
4364instruction after the function call, and the return value of the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4365function is bound to the result argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4366
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4367<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4368
4369<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4370 %retval = call i32 @test(i32 %argc)
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]4371 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4372 %X = tail call i32 @foo() <i>; yields i32</i>
4373 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4374 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]4375
4376 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4377 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]4378 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
4379 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]4380 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]4381 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4382</pre>
4383
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4384</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4385
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4386<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4387<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]4388 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4389</div>
4390
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4391<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4392
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4393<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4394
4395<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4396 &lt;resultval&gt; = va_arg &lt;va_list*&gt; &lt;arglist&gt;, &lt;argty&gt;
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4397</pre>
4398
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4399<h5>Overview:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4400
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4401<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4402the "variable argument" area of a function call. It is used to implement the
4403<tt>va_arg</tt> macro in C.</p>
4404
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4405<h5>Arguments:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4406
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4407<p>This instruction takes a <tt>va_list*</tt> value and the type of
4408the argument. It returns a value of the specified argument type and
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4409increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4410actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4411
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4412<h5>Semantics:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4413
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4414<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
4415type from the specified <tt>va_list</tt> and causes the
4416<tt>va_list</tt> to point to the next argument. For more information,
4417see the variable argument handling <a href="#int_varargs">Intrinsic
4418Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4419
4420<p>It is legal for this instruction to be called in a function which does not
4421take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4422function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4423
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4424<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4425href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4426argument.</p>
4427
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4428<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4429
4430<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4431
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4432</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4433
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4434<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4435<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4436<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4437
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4438<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4439
4440<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4441well known names and semantics and are required to follow certain restrictions.
4442Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4443language that does not require changing all of the transformations in LLVM when
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]4444adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4445
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4446<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4447prefix is reserved in LLVM for intrinsic names; thus, function names may not
4448begin with this prefix. Intrinsic functions must always be external functions:
4449you cannot define the body of intrinsic functions. Intrinsic functions may
4450only be used in call or invoke instructions: it is illegal to take the address
4451of an intrinsic function. Additionally, because intrinsic functions are part
4452of the LLVM language, it is required if any are added that they be documented
4453here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4454
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4455<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
4456a family of functions that perform the same operation but on different data
4457types. Because LLVM can represent over 8 million different integer types,
4458overloading is used commonly to allow an intrinsic function to operate on any
4459integer type. One or more of the argument types or the result type can be
4460overloaded to accept any integer type. Argument types may also be defined as
4461exactly matching a previous argument's type or the result type. This allows an
4462intrinsic function which accepts multiple arguments, but needs all of them to
4463be of the same type, to only be overloaded with respect to a single argument or
4464the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4465
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4466<p>Overloaded intrinsics will have the names of its overloaded argument types
4467encoded into its function name, each preceded by a period. Only those types
4468which are overloaded result in a name suffix. Arguments whose type is matched
4469against another type do not. For example, the <tt>llvm.ctpop</tt> function can
4470take an integer of any width and returns an integer of exactly the same integer
4471width. This leads to a family of functions such as
4472<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
4473Only one type, the return type, is overloaded, and only one type suffix is
4474required. Because the argument's type is matched against the return type, it
4475does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4476
4477<p>To learn how to add an intrinsic function, please see the
4478<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4479</p>
4480
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4481</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4482
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4483<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4484<div class="doc_subsection">
4485 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
4486</div>
4487
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4488<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4489
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4490<p>Variable argument support is defined in LLVM with the <a
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]4491 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4492intrinsic functions. These functions are related to the similarly
4493named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4494
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4495<p>All of these functions operate on arguments that use a
4496target-specific value type "<tt>va_list</tt>". The LLVM assembly
4497language reference manual does not define what this type is, so all
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4498transformations should be prepared to handle these functions regardless of
4499the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4500
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]4501<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4502instruction and the variable argument handling intrinsic functions are
4503used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4504
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4505<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4506<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4507define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4508 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4509 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4510 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4511 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4512
4513 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4514 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4515
4516 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4517 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4518 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4519 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4520 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4521
4522 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4523 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4524 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4525}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4526
4527declare void @llvm.va_start(i8*)
4528declare void @llvm.va_copy(i8*, i8*)
4529declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4530</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4531</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4532
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4533</div>
4534
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4535<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4536<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4537 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4538</div>
4539
4540
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4541<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4542<h5>Syntax:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4543<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4544<h5>Overview:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4545<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4546<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
4547href="#i_va_arg">va_arg</a></tt>.</p>
4548
4549<h5>Arguments:</h5>
4550
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4551<p>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4552
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4553<h5>Semantics:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4554
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4555<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4556macro available in C. In a target-dependent way, it initializes the
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4557<tt>va_list</tt> element to which the argument points, so that the next call to
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4558<tt>va_arg</tt> will produce the first variable argument passed to the function.
4559Unlike the C <tt>va_start</tt> macro, this intrinsic does not need to know the
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4560last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4561
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4562</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4563
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4564<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4565<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4566 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4567</div>
4568
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4569<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4570<h5>Syntax:</h5>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4571<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4572<h5>Overview:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4573
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4574<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4575which has been initialized previously with <tt><a href="#int_va_start">llvm.va_start</a></tt>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4576or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4577
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4578<h5>Arguments:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4579
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4580<p>The argument is a pointer to a <tt>va_list</tt> to destroy.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4581
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4582<h5>Semantics:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4583
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4584<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4585macro available in C. In a target-dependent way, it destroys the
4586<tt>va_list</tt> element to which the argument points. Calls to <a
4587href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
4588<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
4589<tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4590
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4591</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4592
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4593<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4594<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4595 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4596</div>
4597
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4598<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4599
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4600<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4601
4602<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4603 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4604</pre>
4605
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4606<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4607
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4608<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
4609from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4610
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4611<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4612
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4613<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Andrew Lenharthd0a4c622005-06-22 20:38:11 +0000[diff] [blame]4614The second argument is a pointer to a <tt>va_list</tt> element to copy from.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4615
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4616
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4617<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4618
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4619<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
4620macro available in C. In a target-dependent way, it copies the source
4621<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
4622intrinsic is necessary because the <tt><a href="#int_va_start">
4623llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
4624example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4625
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4626</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4627
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4628<!-- ======================================================================= -->
4629<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4630 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
4631</div>
4632
4633<div class="doc_text">
4634
4635<p>
4636LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]4637Collection</a> (GC) requires the implementation and generation of these
4638intrinsics.
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4639These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4640stack</a>, as well as garbage collector implementations that require <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4641href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4642Front-ends for type-safe garbage collected languages should generate these
4643intrinsics to make use of the LLVM garbage collectors. For more details, see <a
4644href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
4645</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]4646
4647<p>The garbage collection intrinsics only operate on objects in the generic
4648 address space (address space zero).</p>
4649
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4650</div>
4651
4652<!-- _______________________________________________________________________ -->
4653<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4654 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4655</div>
4656
4657<div class="doc_text">
4658
4659<h5>Syntax:</h5>
4660
4661<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4662 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4663</pre>
4664
4665<h5>Overview:</h5>
4666
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]4667<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4668the code generator, and allows some metadata to be associated with it.</p>
4669
4670<h5>Arguments:</h5>
4671
4672<p>The first argument specifies the address of a stack object that contains the
4673root pointer. The second pointer (which must be either a constant or a global
4674value address) contains the meta-data to be associated with the root.</p>
4675
4676<h5>Semantics:</h5>
4677
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]4678<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4679location. At compile-time, the code generator generates information to allow
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4680the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
4681intrinsic may only be used in a function which <a href="#gc">specifies a GC
4682algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4683
4684</div>
4685
4686
4687<!-- _______________________________________________________________________ -->
4688<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4689 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4690</div>
4691
4692<div class="doc_text">
4693
4694<h5>Syntax:</h5>
4695
4696<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4697 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4698</pre>
4699
4700<h5>Overview:</h5>
4701
4702<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4703locations, allowing garbage collector implementations that require read
4704barriers.</p>
4705
4706<h5>Arguments:</h5>
4707
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4708<p>The second argument is the address to read from, which should be an address
4709allocated from the garbage collector. The first object is a pointer to the
4710start of the referenced object, if needed by the language runtime (otherwise
4711null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4712
4713<h5>Semantics:</h5>
4714
4715<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4716instruction, but may be replaced with substantially more complex code by the
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4717garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
4718may only be used in a function which <a href="#gc">specifies a GC
4719algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4720
4721</div>
4722
4723
4724<!-- _______________________________________________________________________ -->
4725<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4726 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4727</div>
4728
4729<div class="doc_text">
4730
4731<h5>Syntax:</h5>
4732
4733<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4734 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4735</pre>
4736
4737<h5>Overview:</h5>
4738
4739<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4740locations, allowing garbage collector implementations that require write
4741barriers (such as generational or reference counting collectors).</p>
4742
4743<h5>Arguments:</h5>
4744
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4745<p>The first argument is the reference to store, the second is the start of the
4746object to store it to, and the third is the address of the field of Obj to
4747store to. If the runtime does not require a pointer to the object, Obj may be
4748null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4749
4750<h5>Semantics:</h5>
4751
4752<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4753instruction, but may be replaced with substantially more complex code by the
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4754garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
4755may only be used in a function which <a href="#gc">specifies a GC
4756algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4757
4758</div>
4759
4760
4761
4762<!-- ======================================================================= -->
4763<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4764 <a name="int_codegen">Code Generator Intrinsics</a>
4765</div>
4766
4767<div class="doc_text">
4768<p>
4769These intrinsics are provided by LLVM to expose special features that may only
4770be implemented with code generator support.
4771</p>
4772
4773</div>
4774
4775<!-- _______________________________________________________________________ -->
4776<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4777 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4778</div>
4779
4780<div class="doc_text">
4781
4782<h5>Syntax:</h5>
4783<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4784 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4785</pre>
4786
4787<h5>Overview:</h5>
4788
4789<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4790The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4791target-specific value indicating the return address of the current function
4792or one of its callers.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4793</p>
4794
4795<h5>Arguments:</h5>
4796
4797<p>
4798The argument to this intrinsic indicates which function to return the address
4799for. Zero indicates the calling function, one indicates its caller, etc. The
4800argument is <b>required</b> to be a constant integer value.
4801</p>
4802
4803<h5>Semantics:</h5>
4804
4805<p>
4806The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4807the return address of the specified call frame, or zero if it cannot be
4808identified. The value returned by this intrinsic is likely to be incorrect or 0
4809for arguments other than zero, so it should only be used for debugging purposes.
4810</p>
4811
4812<p>
4813Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4814aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4815source-language caller.
4816</p>
4817</div>
4818
4819
4820<!-- _______________________________________________________________________ -->
4821<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4822 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4823</div>
4824
4825<div class="doc_text">
4826
4827<h5>Syntax:</h5>
4828<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4829 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4830</pre>
4831
4832<h5>Overview:</h5>
4833
4834<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4835The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
4836target-specific frame pointer value for the specified stack frame.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4837</p>
4838
4839<h5>Arguments:</h5>
4840
4841<p>
4842The argument to this intrinsic indicates which function to return the frame
4843pointer for. Zero indicates the calling function, one indicates its caller,
4844etc. The argument is <b>required</b> to be a constant integer value.
4845</p>
4846
4847<h5>Semantics:</h5>
4848
4849<p>
4850The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
4851the frame address of the specified call frame, or zero if it cannot be
4852identified. The value returned by this intrinsic is likely to be incorrect or 0
4853for arguments other than zero, so it should only be used for debugging purposes.
4854</p>
4855
4856<p>
4857Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4858aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4859source-language caller.
4860</p>
4861</div>
4862
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4863<!-- _______________________________________________________________________ -->
4864<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4865 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4866</div>
4867
4868<div class="doc_text">
4869
4870<h5>Syntax:</h5>
4871<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4872 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4873</pre>
4874
4875<h5>Overview:</h5>
4876
4877<p>
4878The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4879the function stack, for use with <a href="#int_stackrestore">
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4880<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
4881features like scoped automatic variable sized arrays in C99.
4882</p>
4883
4884<h5>Semantics:</h5>
4885
4886<p>
4887This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4888href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4889<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
4890<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
4891state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
4892practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
4893that were allocated after the <tt>llvm.stacksave</tt> was executed.
4894</p>
4895
4896</div>
4897
4898<!-- _______________________________________________________________________ -->
4899<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4900 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4901</div>
4902
4903<div class="doc_text">
4904
4905<h5>Syntax:</h5>
4906<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4907 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4908</pre>
4909
4910<h5>Overview:</h5>
4911
4912<p>
4913The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
4914the function stack to the state it was in when the corresponding <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4915href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4916useful for implementing language features like scoped automatic variable sized
4917arrays in C99.
4918</p>
4919
4920<h5>Semantics:</h5>
4921
4922<p>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4923See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4924</p>
4925
4926</div>
4927
4928
4929<!-- _______________________________________________________________________ -->
4930<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4931 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4932</div>
4933
4934<div class="doc_text">
4935
4936<h5>Syntax:</h5>
4937<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4938 declare void @llvm.prefetch(i8* &lt;address&gt;, i32 &lt;rw&gt;, i32 &lt;locality&gt;)
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4939</pre>
4940
4941<h5>Overview:</h5>
4942
4943
4944<p>
4945The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4946a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
4947no
4948effect on the behavior of the program but can change its performance
Chris Lattner2a615362005-02-28 19:47:14 +0000[diff] [blame]4949characteristics.
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4950</p>
4951
4952<h5>Arguments:</h5>
4953
4954<p>
4955<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
4956determining if the fetch should be for a read (0) or write (1), and
4957<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattneraeffb4a2005-03-07 20:31:38 +0000[diff] [blame]4958locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4959<tt>locality</tt> arguments must be constant integers.
4960</p>
4961
4962<h5>Semantics:</h5>
4963
4964<p>
4965This intrinsic does not modify the behavior of the program. In particular,
4966prefetches cannot trap and do not produce a value. On targets that support this
4967intrinsic, the prefetch can provide hints to the processor cache for better
4968performance.
4969</p>
4970
4971</div>
4972
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4973<!-- _______________________________________________________________________ -->
4974<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4975 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4976</div>
4977
4978<div class="doc_text">
4979
4980<h5>Syntax:</h5>
4981<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4982 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4983</pre>
4984
4985<h5>Overview:</h5>
4986
4987
4988<p>
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4989The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]4990(PC) in a region of
4991code to simulators and other tools. The method is target specific, but it is
4992expected that the marker will use exported symbols to transmit the PC of the
4993marker.
4994The marker makes no guarantees that it will remain with any specific instruction
4995after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb3e7afd2006-03-24 07:16:10 +0000[diff] [blame]4996optimizations. The intended use is to be inserted after optimizations to allow
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4997correlations of simulation runs.
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4998</p>
4999
5000<h5>Arguments:</h5>
5001
5002<p>
5003<tt>id</tt> is a numerical id identifying the marker.
5004</p>
5005
5006<h5>Semantics:</h5>
5007
5008<p>
5009This intrinsic does not modify the behavior of the program. Backends that do not
5010support this intrinisic may ignore it.
5011</p>
5012
5013</div>
5014
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5015<!-- _______________________________________________________________________ -->
5016<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5017 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5018</div>
5019
5020<div class="doc_text">
5021
5022<h5>Syntax:</h5>
5023<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5024 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5025</pre>
5026
5027<h5>Overview:</h5>
5028
5029
5030<p>
5031The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5032counter register (or similar low latency, high accuracy clocks) on those targets
5033that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
5034As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
5035should only be used for small timings.
5036</p>
5037
5038<h5>Semantics:</h5>
5039
5040<p>
5041When directly supported, reading the cycle counter should not modify any memory.
5042Implementations are allowed to either return a application specific value or a
5043system wide value. On backends without support, this is lowered to a constant 0.
5044</p>
5045
5046</div>
5047
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5048<!-- ======================================================================= -->
5049<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5050 <a name="int_libc">Standard C Library Intrinsics</a>
5051</div>
5052
5053<div class="doc_text">
5054<p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5055LLVM provides intrinsics for a few important standard C library functions.
5056These intrinsics allow source-language front-ends to pass information about the
5057alignment of the pointer arguments to the code generator, providing opportunity
5058for more efficient code generation.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5059</p>
5060
5061</div>
5062
5063<!-- _______________________________________________________________________ -->
5064<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5065 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5066</div>
5067
5068<div class="doc_text">
5069
5070<h5>Syntax:</h5>
5071<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5072 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5073 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5074 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5075 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5076</pre>
5077
5078<h5>Overview:</h5>
5079
5080<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5081The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5082location to the destination location.
5083</p>
5084
5085<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5086Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5087intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5088</p>
5089
5090<h5>Arguments:</h5>
5091
5092<p>
5093The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5094the source. The third argument is an integer argument
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5095specifying the number of bytes to copy, and the fourth argument is the alignment
5096of the source and destination locations.
5097</p>
5098
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5099<p>
5100If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattnerf0afc2c2006-03-04 00:02:10 +0000[diff] [blame]5101the caller guarantees that both the source and destination pointers are aligned
5102to that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5103</p>
5104
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5105<h5>Semantics:</h5>
5106
5107<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5108The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5109location to the destination location, which are not allowed to overlap. It
5110copies "len" bytes of memory over. If the argument is known to be aligned to
5111some boundary, this can be specified as the fourth argument, otherwise it should
5112be set to 0 or 1.
5113</p>
5114</div>
5115
5116
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5117<!-- _______________________________________________________________________ -->
5118<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5119 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5120</div>
5121
5122<div class="doc_text">
5123
5124<h5>Syntax:</h5>
5125<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5126 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5127 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5128 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5129 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5130</pre>
5131
5132<h5>Overview:</h5>
5133
5134<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5135The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
5136location to the destination location. It is similar to the
Chris Lattner4b2cbcf2008-01-06 19:51:52 +0000[diff] [blame]5137'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5138</p>
5139
5140<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5141Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5142intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5143</p>
5144
5145<h5>Arguments:</h5>
5146
5147<p>
5148The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5149the source. The third argument is an integer argument
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5150specifying the number of bytes to copy, and the fourth argument is the alignment
5151of the source and destination locations.
5152</p>
5153
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5154<p>
5155If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattnerf0afc2c2006-03-04 00:02:10 +0000[diff] [blame]5156the caller guarantees that the source and destination pointers are aligned to
5157that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5158</p>
5159
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5160<h5>Semantics:</h5>
5161
5162<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5163The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5164location to the destination location, which may overlap. It
5165copies "len" bytes of memory over. If the argument is known to be aligned to
5166some boundary, this can be specified as the fourth argument, otherwise it should
5167be set to 0 or 1.
5168</p>
5169</div>
5170
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5171
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5172<!-- _______________________________________________________________________ -->
5173<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5174 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5175</div>
5176
5177<div class="doc_text">
5178
5179<h5>Syntax:</h5>
5180<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5181 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5182 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5183 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5184 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5185</pre>
5186
5187<h5>Overview:</h5>
5188
5189<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5190The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5191byte value.
5192</p>
5193
5194<p>
5195Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
5196does not return a value, and takes an extra alignment argument.
5197</p>
5198
5199<h5>Arguments:</h5>
5200
5201<p>
5202The first argument is a pointer to the destination to fill, the second is the
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5203byte value to fill it with, the third argument is an integer
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5204argument specifying the number of bytes to fill, and the fourth argument is the
5205known alignment of destination location.
5206</p>
5207
5208<p>
5209If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattnerf0afc2c2006-03-04 00:02:10 +0000[diff] [blame]5210the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5211</p>
5212
5213<h5>Semantics:</h5>
5214
5215<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5216The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
5217the
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5218destination location. If the argument is known to be aligned to some boundary,
5219this can be specified as the fourth argument, otherwise it should be set to 0 or
52201.
5221</p>
5222</div>
5223
5224
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5225<!-- _______________________________________________________________________ -->
5226<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5227 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5228</div>
5229
5230<div class="doc_text">
5231
5232<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5233<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5234floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5235types however.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5236<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5237 declare float @llvm.sqrt.f32(float %Val)
5238 declare double @llvm.sqrt.f64(double %Val)
5239 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5240 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5241 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5242</pre>
5243
5244<h5>Overview:</h5>
5245
5246<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5247The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5248returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5249<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner103e2d72008-01-29 07:00:44 +0000[diff] [blame]5250negative numbers other than -0.0 (which allows for better optimization, because
5251there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
5252defined to return -0.0 like IEEE sqrt.
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5253</p>
5254
5255<h5>Arguments:</h5>
5256
5257<p>
5258The argument and return value are floating point numbers of the same type.
5259</p>
5260
5261<h5>Semantics:</h5>
5262
5263<p>
Dan Gohmand6257fe2007-07-16 14:37:41 +0000[diff] [blame]5264This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5265floating point number.
5266</p>
5267</div>
5268
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5269<!-- _______________________________________________________________________ -->
5270<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5271 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5272</div>
5273
5274<div class="doc_text">
5275
5276<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5277<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5278floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5279types however.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5280<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5281 declare float @llvm.powi.f32(float %Val, i32 %power)
5282 declare double @llvm.powi.f64(double %Val, i32 %power)
5283 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5284 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5285 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5286</pre>
5287
5288<h5>Overview:</h5>
5289
5290<p>
5291The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5292specified (positive or negative) power. The order of evaluation of
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5293multiplications is not defined. When a vector of floating point type is
5294used, the second argument remains a scalar integer value.
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5295</p>
5296
5297<h5>Arguments:</h5>
5298
5299<p>
5300The second argument is an integer power, and the first is a value to raise to
5301that power.
5302</p>
5303
5304<h5>Semantics:</h5>
5305
5306<p>
5307This function returns the first value raised to the second power with an
5308unspecified sequence of rounding operations.</p>
5309</div>
5310
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5311<!-- _______________________________________________________________________ -->
5312<div class="doc_subsubsection">
5313 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5314</div>
5315
5316<div class="doc_text">
5317
5318<h5>Syntax:</h5>
5319<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5320floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5321types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5322<pre>
5323 declare float @llvm.sin.f32(float %Val)
5324 declare double @llvm.sin.f64(double %Val)
5325 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5326 declare fp128 @llvm.sin.f128(fp128 %Val)
5327 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5328</pre>
5329
5330<h5>Overview:</h5>
5331
5332<p>
5333The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
5334</p>
5335
5336<h5>Arguments:</h5>
5337
5338<p>
5339The argument and return value are floating point numbers of the same type.
5340</p>
5341
5342<h5>Semantics:</h5>
5343
5344<p>
5345This function returns the sine of the specified operand, returning the
5346same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5347conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5348</div>
5349
5350<!-- _______________________________________________________________________ -->
5351<div class="doc_subsubsection">
5352 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5353</div>
5354
5355<div class="doc_text">
5356
5357<h5>Syntax:</h5>
5358<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5359floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5360types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5361<pre>
5362 declare float @llvm.cos.f32(float %Val)
5363 declare double @llvm.cos.f64(double %Val)
5364 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5365 declare fp128 @llvm.cos.f128(fp128 %Val)
5366 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5367</pre>
5368
5369<h5>Overview:</h5>
5370
5371<p>
5372The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
5373</p>
5374
5375<h5>Arguments:</h5>
5376
5377<p>
5378The argument and return value are floating point numbers of the same type.
5379</p>
5380
5381<h5>Semantics:</h5>
5382
5383<p>
5384This function returns the cosine of the specified operand, returning the
5385same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5386conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5387</div>
5388
5389<!-- _______________________________________________________________________ -->
5390<div class="doc_subsubsection">
5391 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5392</div>
5393
5394<div class="doc_text">
5395
5396<h5>Syntax:</h5>
5397<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5398floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5399types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5400<pre>
5401 declare float @llvm.pow.f32(float %Val, float %Power)
5402 declare double @llvm.pow.f64(double %Val, double %Power)
5403 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5404 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5405 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5406</pre>
5407
5408<h5>Overview:</h5>
5409
5410<p>
5411The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5412specified (positive or negative) power.
5413</p>
5414
5415<h5>Arguments:</h5>
5416
5417<p>
5418The second argument is a floating point power, and the first is a value to
5419raise to that power.
5420</p>
5421
5422<h5>Semantics:</h5>
5423
5424<p>
5425This function returns the first value raised to the second power,
5426returning the
5427same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5428conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5429</div>
5430
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5431
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5432<!-- ======================================================================= -->
5433<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5434 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5435</div>
5436
5437<div class="doc_text">
5438<p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5439LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5440These allow efficient code generation for some algorithms.
5441</p>
5442
5443</div>
5444
5445<!-- _______________________________________________________________________ -->
5446<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5447 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5448</div>
5449
5450<div class="doc_text">
5451
5452<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5453<p>This is an overloaded intrinsic function. You can use bswap on any integer
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5454type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5455<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5456 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5457 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5458 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5459</pre>
5460
5461<h5>Overview:</h5>
5462
5463<p>
Reid Spencer338ea092007-04-02 02:25:19 +0000[diff] [blame]5464The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5465values with an even number of bytes (positive multiple of 16 bits). These are
5466useful for performing operations on data that is not in the target's native
5467byte order.
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5468</p>
5469
5470<h5>Semantics:</h5>
5471
5472<p>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5473The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5474and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
5475intrinsic returns an i32 value that has the four bytes of the input i32
5476swapped, so that if the input bytes are numbered 0, 1, 2, 3 then the returned
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5477i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
5478<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5479additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5480</p>
5481
5482</div>
5483
5484<!-- _______________________________________________________________________ -->
5485<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5486 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5487</div>
5488
5489<div class="doc_text">
5490
5491<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5492<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5493width. Not all targets support all bit widths however.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5494<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5495 declare i8 @llvm.ctpop.i8 (i8 &lt;src&gt;)
5496 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5497 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5498 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5499 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5500</pre>
5501
5502<h5>Overview:</h5>
5503
5504<p>
Chris Lattnerec6cb612006-01-16 22:38:59 +0000[diff] [blame]5505The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
5506value.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5507</p>
5508
5509<h5>Arguments:</h5>
5510
5511<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]5512The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5513integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5514</p>
5515
5516<h5>Semantics:</h5>
5517
5518<p>
5519The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
5520</p>
5521</div>
5522
5523<!-- _______________________________________________________________________ -->
5524<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5525 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5526</div>
5527
5528<div class="doc_text">
5529
5530<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5531<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5532integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5533<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5534 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5535 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5536 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5537 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5538 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5539</pre>
5540
5541<h5>Overview:</h5>
5542
5543<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5544The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5545leading zeros in a variable.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5546</p>
5547
5548<h5>Arguments:</h5>
5549
5550<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]5551The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5552integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5553</p>
5554
5555<h5>Semantics:</h5>
5556
5557<p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5558The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
5559in a variable. If the src == 0 then the result is the size in bits of the type
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5560of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5561</p>
5562</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5563
5564
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5565
5566<!-- _______________________________________________________________________ -->
5567<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5568 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5569</div>
5570
5571<div class="doc_text">
5572
5573<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5574<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5575integer bit width. Not all targets support all bit widths however.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5576<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5577 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5578 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5579 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5580 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5581 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5582</pre>
5583
5584<h5>Overview:</h5>
5585
5586<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5587The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5588trailing zeros.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5589</p>
5590
5591<h5>Arguments:</h5>
5592
5593<p>
5594The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5595integer type. The return type must match the argument type.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5596</p>
5597
5598<h5>Semantics:</h5>
5599
5600<p>
5601The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
5602in a variable. If the src == 0 then the result is the size in bits of the type
5603of src. For example, <tt>llvm.cttz(2) = 1</tt>.
5604</p>
5605</div>
5606
Reid Spencer497d93e2007-04-01 08:27:01 +0000[diff] [blame]5607<!-- _______________________________________________________________________ -->
5608<div class="doc_subsubsection">
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5609 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5610</div>
5611
5612<div class="doc_text">
5613
5614<h5>Syntax:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5615<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5616on any integer bit width.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5617<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5618 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
5619 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5620</pre>
5621
5622<h5>Overview:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5623<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5624range of bits from an integer value and returns them in the same bit width as
5625the original value.</p>
5626
5627<h5>Arguments:</h5>
5628<p>The first argument, <tt>%val</tt> and the result may be integer types of
5629any bit width but they must have the same bit width. The second and third
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5630arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5631
5632<h5>Semantics:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5633<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5634of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
5635<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
5636operates in forward mode.</p>
5637<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
5638right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5639only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
5640<ol>
5641 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
5642 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
5643 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
5644 to determine the number of bits to retain.</li>
5645 <li>A mask of the retained bits is created by shifting a -1 value.</li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5646 <li>The mask is ANDed with <tt>%val</tt> to produce the result.</li>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5647</ol>
Reid Spencerd6a85b52007-05-14 16:14:57 +0000[diff] [blame]5648<p>In reverse mode, a similar computation is made except that the bits are
5649returned in the reverse order. So, for example, if <tt>X</tt> has the value
5650<tt>i16 0x0ACF (101011001111)</tt> and we apply
5651<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
5652<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5653</div>
5654
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5655<div class="doc_subsubsection">
5656 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
5657</div>
5658
5659<div class="doc_text">
5660
5661<h5>Syntax:</h5>
5662<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5663on any integer bit width.</p>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5664<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5665 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
5666 declare i29 @llvm.part.set.i29.i9 (i29 %val, i9 %repl, i32 %lo, i32 %hi)
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5667</pre>
5668
5669<h5>Overview:</h5>
5670<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
5671of bits in an integer value with another integer value. It returns the integer
5672with the replaced bits.</p>
5673
5674<h5>Arguments:</h5>
5675<p>The first argument, <tt>%val</tt> and the result may be integer types of
5676any bit width but they must have the same bit width. <tt>%val</tt> is the value
5677whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
5678integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
5679type since they specify only a bit index.</p>
5680
5681<h5>Semantics:</h5>
5682<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
5683of operation: forwards and reverse. If <tt>%lo</tt> is greater than
5684<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
5685operates in forward mode.</p>
5686<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
5687truncating it down to the size of the replacement area or zero extending it
5688up to that size.</p>
5689<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5690are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5691in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5692to the <tt>%hi</tt>th bit.</p>
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5693<p>In reverse mode, a similar computation is made except that the bits are
5694reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5695<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.</p>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5696<h5>Examples:</h5>
5697<pre>
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5698 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5699 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5700 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5701 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5702 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]5703</pre>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5704</div>
5705
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5706<!-- ======================================================================= -->
5707<div class="doc_subsection">
5708 <a name="int_debugger">Debugger Intrinsics</a>
5709</div>
5710
5711<div class="doc_text">
5712<p>
5713The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
5714are described in the <a
5715href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
5716Debugging</a> document.
5717</p>
5718</div>
5719
5720
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]5721<!-- ======================================================================= -->
5722<div class="doc_subsection">
5723 <a name="int_eh">Exception Handling Intrinsics</a>
5724</div>
5725
5726<div class="doc_text">
5727<p> The LLVM exception handling intrinsics (which all start with
5728<tt>llvm.eh.</tt> prefix), are described in the <a
5729href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
5730Handling</a> document. </p>
5731</div>
5732
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5733<!-- ======================================================================= -->
5734<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5735 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5736</div>
5737
5738<div class="doc_text">
5739<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5740 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5741 the <tt>nest</tt> attribute, from a function. The result is a callable
5742 function pointer lacking the nest parameter - the caller does not need
5743 to provide a value for it. Instead, the value to use is stored in
5744 advance in a "trampoline", a block of memory usually allocated
5745 on the stack, which also contains code to splice the nest value into the
5746 argument list. This is used to implement the GCC nested function address
5747 extension.
5748</p>
5749<p>
5750 For example, if the function is
5751 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
Bill Wendling03295ca2007-09-22 09:23:55 +0000[diff] [blame]5752 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as follows:</p>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5753<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5754 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
5755 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
5756 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
5757 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5758</pre>
Bill Wendling03295ca2007-09-22 09:23:55 +0000[diff] [blame]5759 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
5760 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5761</div>
5762
5763<!-- _______________________________________________________________________ -->
5764<div class="doc_subsubsection">
5765 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
5766</div>
5767<div class="doc_text">
5768<h5>Syntax:</h5>
5769<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5770declare i8* @llvm.init.trampoline(i8* &lt;tramp&gt;, i8* &lt;func&gt;, i8* &lt;nval&gt;)
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5771</pre>
5772<h5>Overview:</h5>
5773<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5774 This fills the memory pointed to by <tt>tramp</tt> with code
5775 and returns a function pointer suitable for executing it.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5776</p>
5777<h5>Arguments:</h5>
5778<p>
5779 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
5780 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
5781 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsc00c2ba2007-08-22 23:39:54 +0000[diff] [blame]5782 intrinsic. Note that the size and the alignment are target-specific - LLVM
5783 currently provides no portable way of determining them, so a front-end that
5784 generates this intrinsic needs to have some target-specific knowledge.
5785 The <tt>func</tt> argument must hold a function bitcast to an <tt>i8*</tt>.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5786</p>
5787<h5>Semantics:</h5>
5788<p>
5789 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5790 dependent code, turning it into a function. A pointer to this function is
5791 returned, but needs to be bitcast to an
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5792 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5793 before being called. The new function's signature is the same as that of
5794 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
5795 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
5796 of pointer type. Calling the new function is equivalent to calling
5797 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
5798 missing <tt>nest</tt> argument. If, after calling
5799 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
5800 modified, then the effect of any later call to the returned function pointer is
5801 undefined.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5802</p>
5803</div>
5804
5805<!-- ======================================================================= -->
5806<div class="doc_subsection">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]5807 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
5808</div>
5809
5810<div class="doc_text">
5811<p>
5812 These intrinsic functions expand the "universal IR" of LLVM to represent
5813 hardware constructs for atomic operations and memory synchronization. This
5814 provides an interface to the hardware, not an interface to the programmer. It
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5815 is aimed at a low enough level to allow any programming models or APIs
5816 (Application Programming Interfaces) which
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]5817 need atomic behaviors to map cleanly onto it. It is also modeled primarily on
5818 hardware behavior. Just as hardware provides a "universal IR" for source
5819 languages, it also provides a starting point for developing a "universal"
5820 atomic operation and synchronization IR.
5821</p>
5822<p>
5823 These do <em>not</em> form an API such as high-level threading libraries,
5824 software transaction memory systems, atomic primitives, and intrinsic
5825 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
5826 application libraries. The hardware interface provided by LLVM should allow
5827 a clean implementation of all of these APIs and parallel programming models.
5828 No one model or paradigm should be selected above others unless the hardware
5829 itself ubiquitously does so.
5830
5831</p>
5832</div>
5833
5834<!-- _______________________________________________________________________ -->
5835<div class="doc_subsubsection">
5836 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
5837</div>
5838<div class="doc_text">
5839<h5>Syntax:</h5>
5840<pre>
5841declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;,
5842i1 &lt;device&gt; )
5843
5844</pre>
5845<h5>Overview:</h5>
5846<p>
5847 The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
5848 specific pairs of memory access types.
5849</p>
5850<h5>Arguments:</h5>
5851<p>
5852 The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
5853 The first four arguments enables a specific barrier as listed below. The fith
5854 argument specifies that the barrier applies to io or device or uncached memory.
5855
5856</p>
5857 <ul>
5858 <li><tt>ll</tt>: load-load barrier</li>
5859 <li><tt>ls</tt>: load-store barrier</li>
5860 <li><tt>sl</tt>: store-load barrier</li>
5861 <li><tt>ss</tt>: store-store barrier</li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5862 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]5863 </ul>
5864<h5>Semantics:</h5>
5865<p>
5866 This intrinsic causes the system to enforce some ordering constraints upon
5867 the loads and stores of the program. This barrier does not indicate
5868 <em>when</em> any events will occur, it only enforces an <em>order</em> in
5869 which they occur. For any of the specified pairs of load and store operations
5870 (f.ex. load-load, or store-load), all of the first operations preceding the
5871 barrier will complete before any of the second operations succeeding the
5872 barrier begin. Specifically the semantics for each pairing is as follows:
5873</p>
5874 <ul>
5875 <li><tt>ll</tt>: All loads before the barrier must complete before any load
5876 after the barrier begins.</li>
5877
5878 <li><tt>ls</tt>: All loads before the barrier must complete before any
5879 store after the barrier begins.</li>
5880 <li><tt>ss</tt>: All stores before the barrier must complete before any
5881 store after the barrier begins.</li>
5882 <li><tt>sl</tt>: All stores before the barrier must complete before any
5883 load after the barrier begins.</li>
5884 </ul>
5885<p>
5886 These semantics are applied with a logical "and" behavior when more than one
5887 is enabled in a single memory barrier intrinsic.
5888</p>
5889<p>
5890 Backends may implement stronger barriers than those requested when they do not
5891 support as fine grained a barrier as requested. Some architectures do not
5892 need all types of barriers and on such architectures, these become noops.
5893</p>
5894<h5>Example:</h5>
5895<pre>
5896%ptr = malloc i32
5897 store i32 4, %ptr
5898
5899%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
5900 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
5901 <i>; guarantee the above finishes</i>
5902 store i32 8, %ptr <i>; before this begins</i>
5903</pre>
5904</div>
5905
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5906<!-- _______________________________________________________________________ -->
5907<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]5908 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5909</div>
5910<div class="doc_text">
5911<h5>Syntax:</h5>
5912<p>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]5913 This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
5914 any integer bit width and for different address spaces. Not all targets
5915 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5916
5917<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]5918declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
5919declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
5920declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
5921declare i64 @llvm.atomic.cmp.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;cmp&gt;, i64 &lt;val&gt; )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5922
5923</pre>
5924<h5>Overview:</h5>
5925<p>
5926 This loads a value in memory and compares it to a given value. If they are
5927 equal, it stores a new value into the memory.
5928</p>
5929<h5>Arguments:</h5>
5930<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]5931 The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5932 well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
5933 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
5934 this integer type. While any bit width integer may be used, targets may only
5935 lower representations they support in hardware.
5936
5937</p>
5938<h5>Semantics:</h5>
5939<p>
5940 This entire intrinsic must be executed atomically. It first loads the value
5941 in memory pointed to by <tt>ptr</tt> and compares it with the value
5942 <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
5943 loaded value is yielded in all cases. This provides the equivalent of an
5944 atomic compare-and-swap operation within the SSA framework.
5945</p>
5946<h5>Examples:</h5>
5947
5948<pre>
5949%ptr = malloc i32
5950 store i32 4, %ptr
5951
5952%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]5953%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5954 <i>; yields {i32}:result1 = 4</i>
5955%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
5956%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
5957
5958%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]5959%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5960 <i>; yields {i32}:result2 = 8</i>
5961%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
5962
5963%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
5964</pre>
5965</div>
5966
5967<!-- _______________________________________________________________________ -->
5968<div class="doc_subsubsection">
5969 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
5970</div>
5971<div class="doc_text">
5972<h5>Syntax:</h5>
5973
5974<p>
5975 This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
5976 integer bit width. Not all targets support all bit widths however.</p>
5977<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]5978declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
5979declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
5980declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
5981declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5982
5983</pre>
5984<h5>Overview:</h5>
5985<p>
5986 This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
5987 the value from memory. It then stores the value in <tt>val</tt> in the memory
5988 at <tt>ptr</tt>.
5989</p>
5990<h5>Arguments:</h5>
5991
5992<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]5993 The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5994 <tt>val</tt> argument and the result must be integers of the same bit width.
5995 The first argument, <tt>ptr</tt>, must be a pointer to a value of this
5996 integer type. The targets may only lower integer representations they
5997 support.
5998</p>
5999<h5>Semantics:</h5>
6000<p>
6001 This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6002 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6003 equivalent of an atomic swap operation within the SSA framework.
6004
6005</p>
6006<h5>Examples:</h5>
6007<pre>
6008%ptr = malloc i32
6009 store i32 4, %ptr
6010
6011%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6012%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6013 <i>; yields {i32}:result1 = 4</i>
6014%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6015%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6016
6017%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6018%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6019 <i>; yields {i32}:result2 = 8</i>
6020
6021%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6022%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6023</pre>
6024</div>
6025
6026<!-- _______________________________________________________________________ -->
6027<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6028 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6029
6030</div>
6031<div class="doc_text">
6032<h5>Syntax:</h5>
6033<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6034 This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on any
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6035 integer bit width. Not all targets support all bit widths however.</p>
6036<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6037declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6038declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6039declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6040declare i64 @llvm.atomic.load.add.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6041
6042</pre>
6043<h5>Overview:</h5>
6044<p>
6045 This intrinsic adds <tt>delta</tt> to the value stored in memory at
6046 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6047</p>
6048<h5>Arguments:</h5>
6049<p>
6050
6051 The intrinsic takes two arguments, the first a pointer to an integer value
6052 and the second an integer value. The result is also an integer value. These
6053 integer types can have any bit width, but they must all have the same bit
6054 width. The targets may only lower integer representations they support.
6055</p>
6056<h5>Semantics:</h5>
6057<p>
6058 This intrinsic does a series of operations atomically. It first loads the
6059 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6060 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6061</p>
6062
6063<h5>Examples:</h5>
6064<pre>
6065%ptr = malloc i32
6066 store i32 4, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6067%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6068 <i>; yields {i32}:result1 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6069%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6070 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6071%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6072 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6073%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6074</pre>
6075</div>
6076
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6077<!-- _______________________________________________________________________ -->
6078<div class="doc_subsubsection">
6079 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6080
6081</div>
6082<div class="doc_text">
6083<h5>Syntax:</h5>
6084<p>
6085 This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6086 any integer bit width and for different address spaces. Not all targets
6087 support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6088<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6089declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6090declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6091declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6092declare i64 @llvm.atomic.load.sub.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6093
6094</pre>
6095<h5>Overview:</h5>
6096<p>
6097 This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6098 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6099</p>
6100<h5>Arguments:</h5>
6101<p>
6102
6103 The intrinsic takes two arguments, the first a pointer to an integer value
6104 and the second an integer value. The result is also an integer value. These
6105 integer types can have any bit width, but they must all have the same bit
6106 width. The targets may only lower integer representations they support.
6107</p>
6108<h5>Semantics:</h5>
6109<p>
6110 This intrinsic does a series of operations atomically. It first loads the
6111 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6112 result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6113</p>
6114
6115<h5>Examples:</h5>
6116<pre>
6117%ptr = malloc i32
6118 store i32 8, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6119%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6120 <i>; yields {i32}:result1 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6121%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6122 <i>; yields {i32}:result2 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6123%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6124 <i>; yields {i32}:result3 = 2</i>
6125%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6126</pre>
6127</div>
6128
6129<!-- _______________________________________________________________________ -->
6130<div class="doc_subsubsection">
6131 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6132 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6133 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6134 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
6135
6136</div>
6137<div class="doc_text">
6138<h5>Syntax:</h5>
6139<p>
6140 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
6141 <tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6142 <tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
6143 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6144<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6145declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6146declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6147declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6148declare i64 @llvm.atomic.load.and.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6149
6150</pre>
6151
6152<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6153declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6154declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6155declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6156declare i64 @llvm.atomic.load.or.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6157
6158</pre>
6159
6160<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6161declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6162declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6163declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6164declare i64 @llvm.atomic.load.nand.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6165
6166</pre>
6167
6168<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6169declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6170declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6171declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6172declare i64 @llvm.atomic.load.xor.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6173
6174</pre>
6175<h5>Overview:</h5>
6176<p>
6177 These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6178 the value stored in memory at <tt>ptr</tt>. It yields the original value
6179 at <tt>ptr</tt>.
6180</p>
6181<h5>Arguments:</h5>
6182<p>
6183
6184 These intrinsics take two arguments, the first a pointer to an integer value
6185 and the second an integer value. The result is also an integer value. These
6186 integer types can have any bit width, but they must all have the same bit
6187 width. The targets may only lower integer representations they support.
6188</p>
6189<h5>Semantics:</h5>
6190<p>
6191 These intrinsics does a series of operations atomically. They first load the
6192 value stored at <tt>ptr</tt>. They then do the bitwise operation
6193 <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
6194 value stored at <tt>ptr</tt>.
6195</p>
6196
6197<h5>Examples:</h5>
6198<pre>
6199%ptr = malloc i32
6200 store i32 0x0F0F, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6201%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6202 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6203%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6204 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6205%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6206 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6207%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6208 <i>; yields {i32}:result3 = FF</i>
6209%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6210</pre>
6211</div>
6212
6213
6214<!-- _______________________________________________________________________ -->
6215<div class="doc_subsubsection">
6216 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6217 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6218 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6219 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
6220
6221</div>
6222<div class="doc_text">
6223<h5>Syntax:</h5>
6224<p>
6225 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6226 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6227 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6228 address spaces. Not all targets
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6229 support all bit widths however.</p>
6230<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6231declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6232declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6233declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6234declare i64 @llvm.atomic.load.max.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6235
6236</pre>
6237
6238<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6239declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6240declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6241declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6242declare i64 @llvm.atomic.load.min.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6243
6244</pre>
6245
6246<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6247declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6248declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6249declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6250declare i64 @llvm.atomic.load.umax.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6251
6252</pre>
6253
6254<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6255declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6256declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6257declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6258declare i64 @llvm.atomic.load.umin.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6259
6260</pre>
6261<h5>Overview:</h5>
6262<p>
6263 These intrinsics takes the signed or unsigned minimum or maximum of
6264 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6265 original value at <tt>ptr</tt>.
6266</p>
6267<h5>Arguments:</h5>
6268<p>
6269
6270 These intrinsics take two arguments, the first a pointer to an integer value
6271 and the second an integer value. The result is also an integer value. These
6272 integer types can have any bit width, but they must all have the same bit
6273 width. The targets may only lower integer representations they support.
6274</p>
6275<h5>Semantics:</h5>
6276<p>
6277 These intrinsics does a series of operations atomically. They first load the
6278 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
6279 <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
6280 the original value stored at <tt>ptr</tt>.
6281</p>
6282
6283<h5>Examples:</h5>
6284<pre>
6285%ptr = malloc i32
6286 store i32 7, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6287%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6288 <i>; yields {i32}:result0 = 7</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6289%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6290 <i>; yields {i32}:result1 = -2</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6291%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6292 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6293%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6294 <i>; yields {i32}:result3 = 8</i>
6295%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6296</pre>
6297</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6298
6299<!-- ======================================================================= -->
6300<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6301 <a name="int_general">General Intrinsics</a>
6302</div>
6303
6304<div class="doc_text">
6305<p> This class of intrinsics is designed to be generic and has
6306no specific purpose. </p>
6307</div>
6308
6309<!-- _______________________________________________________________________ -->
6310<div class="doc_subsubsection">
6311 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6312</div>
6313
6314<div class="doc_text">
6315
6316<h5>Syntax:</h5>
6317<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]6318 declare void @llvm.var.annotation(i8* &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6319</pre>
6320
6321<h5>Overview:</h5>
6322
6323<p>
6324The '<tt>llvm.var.annotation</tt>' intrinsic
6325</p>
6326
6327<h5>Arguments:</h5>
6328
6329<p>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]6330The first argument is a pointer to a value, the second is a pointer to a
6331global string, the third is a pointer to a global string which is the source
6332file name, and the last argument is the line number.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6333</p>
6334
6335<h5>Semantics:</h5>
6336
6337<p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6338This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6339This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6340annotations. These have no other defined use, they are ignored by code
6341generation and optimization.
6342</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6343</div>
6344
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6345<!-- _______________________________________________________________________ -->
6346<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]6347 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6348</div>
6349
6350<div class="doc_text">
6351
6352<h5>Syntax:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6353<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6354any integer bit width.
6355</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6356<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]6357 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6358 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6359 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6360 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6361 declare i256 @llvm.annotation.i256(i256 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6362</pre>
6363
6364<h5>Overview:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6365
6366<p>
6367The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6368</p>
6369
6370<h5>Arguments:</h5>
6371
6372<p>
6373The first argument is an integer value (result of some expression),
6374the second is a pointer to a global string, the third is a pointer to a global
6375string which is the source file name, and the last argument is the line number.
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6376It returns the value of the first argument.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6377</p>
6378
6379<h5>Semantics:</h5>
6380
6381<p>
6382This intrinsic allows annotations to be put on arbitrary expressions
6383with arbitrary strings. This can be useful for special purpose optimizations
6384that want to look for these annotations. These have no other defined use, they
6385are ignored by code generation and optimization.
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6386</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6387</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6388
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6389<!-- _______________________________________________________________________ -->
6390<div class="doc_subsubsection">
6391 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6392</div>
6393
6394<div class="doc_text">
6395
6396<h5>Syntax:</h5>
6397<pre>
6398 declare void @llvm.trap()
6399</pre>
6400
6401<h5>Overview:</h5>
6402
6403<p>
6404The '<tt>llvm.trap</tt>' intrinsic
6405</p>
6406
6407<h5>Arguments:</h5>
6408
6409<p>
6410None
6411</p>
6412
6413<h5>Semantics:</h5>
6414
6415<p>
6416This intrinsics is lowered to the target dependent trap instruction. If the
6417target does not have a trap instruction, this intrinsic will be lowered to the
6418call of the abort() function.
6419</p>
6420</div>
6421
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6422<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6423<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6424<address>
6425 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
6426 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
6427 <a href="http://validator.w3.org/check/referer"><img
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Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6429
6430 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]6431 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6432 Last modified: $Date$
6433</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]6434
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