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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / baa39d866410d1f1d7ef6795f82c968bd94ea4a0 / . / 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>
Bill Wendling3c44f5b2008-11-18 22:10:53 +0000[diff] [blame]217 <li><a href="#int_atomics">Atomic intrinsics</a>
218 <ol>
219 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
220 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
221 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
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>
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">
Bill Wendling69e4adb2008-11-19 05:56:17 +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">
Bill Wendling69e4adb2008-11-19 05:56:17 +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">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]241 '<tt>llvm.trap</tt>' Intrinsic</a></li>
242 <li><a href="#int_stackprotector">
243 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]244 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]245 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]246 </ol>
247 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]248</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]249
250<div class="doc_author">
251 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
252 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]253</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]254
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]255<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]256<div class="doc_section"> <a name="abstract">Abstract </a></div>
257<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]258
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]259<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]260<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling837f39b2008-08-05 22:29:16 +0000[diff] [blame]261LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]262type safety, low-level operations, flexibility, and the capability of
263representing 'all' high-level languages cleanly. It is the common code
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]264representation used throughout all phases of the LLVM compilation
265strategy.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]266</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]267
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]268<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]269<div class="doc_section"> <a name="introduction">Introduction</a> </div>
270<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]271
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]272<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]273
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]274<p>The LLVM code representation is designed to be used in three
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]275different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]276representation (suitable for fast loading by a Just-In-Time compiler),
277and as a human readable assembly language representation. This allows
278LLVM to provide a powerful intermediate representation for efficient
279compiler transformations and analysis, while providing a natural means
280to debug and visualize the transformations. The three different forms
281of LLVM are all equivalent. This document describes the human readable
282representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]283
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]284<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]285while being expressive, typed, and extensible at the same time. It
286aims to be a "universal IR" of sorts, by being at a low enough level
287that high-level ideas may be cleanly mapped to it (similar to how
288microprocessors are "universal IR's", allowing many source languages to
289be mapped to them). By providing type information, LLVM can be used as
290the target of optimizations: for example, through pointer analysis, it
291can be proven that a C automatic variable is never accessed outside of
292the current function... allowing it to be promoted to a simple SSA
293value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]294
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]295</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]296
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]297<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]298<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]299
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]300<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]301
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]302<p>It is important to note that this document describes 'well formed'
303LLVM assembly language. There is a difference between what the parser
304accepts and what is considered 'well formed'. For example, the
305following instruction is syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]306
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]307<div class="doc_code">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]308<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]309%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]310</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]311</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]312
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]313<p>...because the definition of <tt>%x</tt> does not dominate all of
314its uses. The LLVM infrastructure provides a verification pass that may
315be used to verify that an LLVM module is well formed. This pass is
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]316automatically run by the parser after parsing input assembly and by
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]317the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]318by the verifier pass indicate bugs in transformation passes or input to
319the parser.</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]320</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]321
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]322<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]323
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]324<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]325<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]326<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]327
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]328<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]329
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]330 <p>LLVM identifiers come in two basic types: global and local. Global
331 identifiers (functions, global variables) begin with the @ character. Local
332 identifiers (register names, types) begin with the % character. Additionally,
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]333 there are three different formats for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]334
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]335<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]336 <li>Named values are represented as a string of characters with their prefix.
337 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
338 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]339 Identifiers which require other characters in their names can be surrounded
Daniel Dunbar76dea952008-10-14 23:51:43 +0000[diff] [blame]340 with quotes. Special characters may be escaped using "\xx" where xx is the
341 ASCII code for the character in hexadecimal. In this way, any character can
342 be used in a name value, even quotes themselves.
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]343
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]344 <li>Unnamed values are represented as an unsigned numeric value with their
345 prefix. For example, %12, @2, %44.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]346
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]347 <li>Constants, which are described in a <a href="#constants">section about
348 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]349</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]350
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]351<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]352don't need to worry about name clashes with reserved words, and the set of
353reserved words may be expanded in the future without penalty. Additionally,
354unnamed identifiers allow a compiler to quickly come up with a temporary
355variable without having to avoid symbol table conflicts.</p>
356
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]357<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]358languages. There are keywords for different opcodes
359('<tt><a href="#i_add">add</a></tt>',
360 '<tt><a href="#i_bitcast">bitcast</a></tt>',
361 '<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]362href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]363and others. These reserved words cannot conflict with variable names, because
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]364none of them start with a prefix character ('%' or '@').</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]365
366<p>Here is an example of LLVM code to multiply the integer variable
367'<tt>%X</tt>' by 8:</p>
368
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]369<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]370
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]371<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]372<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]373%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]374</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]375</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]376
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]377<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]378
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]379<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]380<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]381%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]382</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]383</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]384
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]385<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]386
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]387<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]388<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]389<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
390<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
391%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]392</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]393</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]394
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]395<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
396important lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]397
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]398<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]399
400 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
401 line.</li>
402
403 <li>Unnamed temporaries are created when the result of a computation is not
404 assigned to a named value.</li>
405
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]406 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]407
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]408</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]409
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]410<p>...and it also shows a convention that we follow in this document. When
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]411demonstrating instructions, we will follow an instruction with a comment that
412defines the type and name of value produced. Comments are shown in italic
413text.</p>
414
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]415</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]416
417<!-- *********************************************************************** -->
418<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
419<!-- *********************************************************************** -->
420
421<!-- ======================================================================= -->
422<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
423</div>
424
425<div class="doc_text">
426
427<p>LLVM programs are composed of "Module"s, each of which is a
428translation unit of the input programs. Each module consists of
429functions, global variables, and symbol table entries. Modules may be
430combined together with the LLVM linker, which merges function (and
431global variable) definitions, resolves forward declarations, and merges
432symbol table entries. Here is an example of the "hello world" module:</p>
433
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]434<div class="doc_code">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]435<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]436<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
437 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]438
439<i>; External declaration of the puts function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]440<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]441
442<i>; Definition of main function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]443define i32 @main() { <i>; i32()* </i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]444 <i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]445 %cast210 = <a
Chris Lattner6c0955b2007-06-12 17:01:15 +0000[diff] [blame]446 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]447
448 <i>; Call puts function to write out the string to stdout...</i>
449 <a
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]450 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]451 <a
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]452 href="#i_ret">ret</a> i32 0<br>}<br>
453</pre>
454</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]455
456<p>This example is made up of a <a href="#globalvars">global variable</a>
457named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
458function, and a <a href="#functionstructure">function definition</a>
459for "<tt>main</tt>".</p>
460
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]461<p>In general, a module is made up of a list of global values,
462where both functions and global variables are global values. Global values are
463represented by a pointer to a memory location (in this case, a pointer to an
464array of char, and a pointer to a function), and have one of the following <a
465href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]466
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]467</div>
468
469<!-- ======================================================================= -->
470<div class="doc_subsection">
471 <a name="linkage">Linkage Types</a>
472</div>
473
474<div class="doc_text">
475
476<p>
477All Global Variables and Functions have one of the following types of linkage:
478</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]479
480<dl>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]481
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]482 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]483
484 <dd>Global values with internal linkage are only directly accessible by
485 objects in the current module. In particular, linking code into a module with
486 an internal global value may cause the internal to be renamed as necessary to
487 avoid collisions. Because the symbol is internal to the module, all
488 references can be updated. This corresponds to the notion of the
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]489 '<tt>static</tt>' keyword in C.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]490 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]491
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]492 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]493
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]494 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
495 the same name when linkage occurs. This is typically used to implement
496 inline functions, templates, or other code which must be generated in each
497 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
498 allowed to be discarded.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]499 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]500
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]501 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
502
503 <dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
504 linkage, except that unreferenced <tt>common</tt> globals may not be
505 discarded. This is used for globals that may be emitted in multiple
506 translation units, but that are not guaranteed to be emitted into every
507 translation unit that uses them. One example of this is tentative
508 definitions in C, such as "<tt>int X;</tt>" at global scope.
509 </dd>
510
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]511 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]512
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]513 <dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
514 that some targets may choose to emit different assembly sequences for them
515 for target-dependent reasons. This is used for globals that are declared
516 "weak" in C source code.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]517 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]518
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]519 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]520
521 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
522 pointer to array type. When two global variables with appending linkage are
523 linked together, the two global arrays are appended together. This is the
524 LLVM, typesafe, equivalent of having the system linker append together
525 "sections" with identical names when .o files are linked.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]526 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]527
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]528 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]529 <dd>The semantics of this linkage follow the ELF object file model: the
530 symbol is weak until linked, if not linked, the symbol becomes null instead
531 of being an undefined reference.
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]532 </dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]533
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]534 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]535
536 <dd>If none of the above identifiers are used, the global is externally
537 visible, meaning that it participates in linkage and can be used to resolve
538 external symbol references.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]539 </dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]540</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]541
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]542 <p>
543 The next two types of linkage are targeted for Microsoft Windows platform
544 only. They are designed to support importing (exporting) symbols from (to)
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]545 DLLs (Dynamic Link Libraries).
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]546 </p>
547
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]548 <dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]549 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
550
551 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
552 or variable via a global pointer to a pointer that is set up by the DLL
553 exporting the symbol. On Microsoft Windows targets, the pointer name is
554 formed by combining <code>_imp__</code> and the function or variable name.
555 </dd>
556
557 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
558
559 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
560 pointer to a pointer in a DLL, so that it can be referenced with the
561 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
562 name is formed by combining <code>_imp__</code> and the function or variable
563 name.
564 </dd>
565
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]566</dl>
567
Dan Gohmanf0032762008-11-24 17:18:39 +0000[diff] [blame]568<p>For example, since the "<tt>.LC0</tt>"
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]569variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
570variable and was linked with this one, one of the two would be renamed,
571preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
572external (i.e., lacking any linkage declarations), they are accessible
Reid Spencerac8d2762007-01-05 00:59:10 +0000[diff] [blame]573outside of the current module.</p>
574<p>It is illegal for a function <i>declaration</i>
575to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]576or <tt>extern_weak</tt>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]577<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]578linkages.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]579</div>
580
581<!-- ======================================================================= -->
582<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]583 <a name="callingconv">Calling Conventions</a>
584</div>
585
586<div class="doc_text">
587
588<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
589and <a href="#i_invoke">invokes</a> can all have an optional calling convention
590specified for the call. The calling convention of any pair of dynamic
591caller/callee must match, or the behavior of the program is undefined. The
592following calling conventions are supported by LLVM, and more may be added in
593the future:</p>
594
595<dl>
596 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
597
598 <dd>This calling convention (the default if no other calling convention is
599 specified) matches the target C calling conventions. This calling convention
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]600 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencerc28d2bc2006-12-31 21:30:18 +0000[diff] [blame]601 prototype and implemented declaration of the function (as does normal C).
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]602 </dd>
603
604 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
605
606 <dd>This calling convention attempts to make calls as fast as possible
607 (e.g. by passing things in registers). This calling convention allows the
608 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]609 without having to conform to an externally specified ABI (Application Binary
610 Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer9097d142008-05-14 09:17:12 +0000[diff] [blame]611 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
612 supported. This calling convention does not support varargs and requires the
613 prototype of all callees to exactly match the prototype of the function
614 definition.
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]615 </dd>
616
617 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
618
619 <dd>This calling convention attempts to make code in the caller as efficient
620 as possible under the assumption that the call is not commonly executed. As
621 such, these calls often preserve all registers so that the call does not break
622 any live ranges in the caller side. This calling convention does not support
623 varargs and requires the prototype of all callees to exactly match the
624 prototype of the function definition.
625 </dd>
626
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]627 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]628
629 <dd>Any calling convention may be specified by number, allowing
630 target-specific calling conventions to be used. Target specific calling
631 conventions start at 64.
632 </dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]633</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]634
635<p>More calling conventions can be added/defined on an as-needed basis, to
636support pascal conventions or any other well-known target-independent
637convention.</p>
638
639</div>
640
641<!-- ======================================================================= -->
642<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]643 <a name="visibility">Visibility Styles</a>
644</div>
645
646<div class="doc_text">
647
648<p>
649All Global Variables and Functions have one of the following visibility styles:
650</p>
651
652<dl>
653 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
654
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]655 <dd>On targets that use the ELF object file format, default visibility means
656 that the declaration is visible to other
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]657 modules and, in shared libraries, means that the declared entity may be
658 overridden. On Darwin, default visibility means that the declaration is
659 visible to other modules. Default visibility corresponds to "external
660 linkage" in the language.
661 </dd>
662
663 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
664
665 <dd>Two declarations of an object with hidden visibility refer to the same
666 object if they are in the same shared object. Usually, hidden visibility
667 indicates that the symbol will not be placed into the dynamic symbol table,
668 so no other module (executable or shared library) can reference it
669 directly.
670 </dd>
671
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]672 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
673
674 <dd>On ELF, protected visibility indicates that the symbol will be placed in
675 the dynamic symbol table, but that references within the defining module will
676 bind to the local symbol. That is, the symbol cannot be overridden by another
677 module.
678 </dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]679</dl>
680
681</div>
682
683<!-- ======================================================================= -->
684<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]685 <a name="globalvars">Global Variables</a>
686</div>
687
688<div class="doc_text">
689
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]690<p>Global variables define regions of memory allocated at compilation time
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]691instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]692an explicit section to be placed in, and may have an optional explicit alignment
693specified. A variable may be defined as "thread_local", which means that it
694will not be shared by threads (each thread will have a separated copy of the
695variable). A variable may be defined as a global "constant," which indicates
696that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]697optimization, allowing the global data to be placed in the read-only section of
698an executable, etc). Note that variables that need runtime initialization
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]699cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]700
701<p>
702LLVM explicitly allows <em>declarations</em> of global variables to be marked
703constant, even if the final definition of the global is not. This capability
704can be used to enable slightly better optimization of the program, but requires
705the language definition to guarantee that optimizations based on the
706'constantness' are valid for the translation units that do not include the
707definition.
708</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]709
710<p>As SSA values, global variables define pointer values that are in
711scope (i.e. they dominate) all basic blocks in the program. Global
712variables always define a pointer to their "content" type because they
713describe a region of memory, and all memory objects in LLVM are
714accessed through pointers.</p>
715
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]716<p>A global variable may be declared to reside in a target-specifc numbered
717address space. For targets that support them, address spaces may affect how
718optimizations are performed and/or what target instructions are used to access
Christopher Lambd49e18d2007-12-12 08:44:39 +0000[diff] [blame]719the variable. The default address space is zero. The address space qualifier
720must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]721
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]722<p>LLVM allows an explicit section to be specified for globals. If the target
723supports it, it will emit globals to the section specified.</p>
724
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]725<p>An explicit alignment may be specified for a global. If not present, or if
726the alignment is set to zero, the alignment of the global is set by the target
727to whatever it feels convenient. If an explicit alignment is specified, the
728global is forced to have at least that much alignment. All alignments must be
729a power of 2.</p>
730
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]731<p>For example, the following defines a global in a numbered address space with
732an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]733
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]734<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]735<pre>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]736@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]737</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]738</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]739
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]740</div>
741
742
743<!-- ======================================================================= -->
744<div class="doc_subsection">
745 <a name="functionstructure">Functions</a>
746</div>
747
748<div class="doc_text">
749
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]750<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
751an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]752<a href="#visibility">visibility style</a>, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]753<a href="#callingconv">calling convention</a>, a return type, an optional
754<a href="#paramattrs">parameter attribute</a> for the return type, a function
755name, a (possibly empty) argument list (each with optional
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]756<a href="#paramattrs">parameter attributes</a>), optional
757<a href="#fnattrs">function attributes</a>, an optional section,
758an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner0c46a7d2008-10-04 18:10:21 +0000[diff] [blame]759an opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]760
761LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
762optional <a href="#linkage">linkage type</a>, an optional
763<a href="#visibility">visibility style</a>, an optional
764<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]765<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]766name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksene754abe2007-12-10 03:30:21 +0000[diff] [blame]767<a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]768
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]769<p>A function definition contains a list of basic blocks, forming the CFG
770(Control Flow Graph) for
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]771the function. Each basic block may optionally start with a label (giving the
772basic block a symbol table entry), contains a list of instructions, and ends
773with a <a href="#terminators">terminator</a> instruction (such as a branch or
774function return).</p>
775
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]776<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]777executed on entrance to the function, and it is not allowed to have predecessor
778basic blocks (i.e. there can not be any branches to the entry block of a
779function). Because the block can have no predecessors, it also cannot have any
780<a href="#i_phi">PHI nodes</a>.</p>
781
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]782<p>LLVM allows an explicit section to be specified for functions. If the target
783supports it, it will emit functions to the section specified.</p>
784
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]785<p>An explicit alignment may be specified for a function. If not present, or if
786the alignment is set to zero, the alignment of the function is set by the target
787to whatever it feels convenient. If an explicit alignment is specified, the
788function is forced to have at least that much alignment. All alignments must be
789a power of 2.</p>
790
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]791 <h5>Syntax:</h5>
792
793<div class="doc_code">
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]794<tt>
795define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
796 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
797 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
798 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
799 [<a href="#gc">gc</a>] { ... }
800</tt>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]801</div>
802
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]803</div>
804
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]805
806<!-- ======================================================================= -->
807<div class="doc_subsection">
808 <a name="aliasstructure">Aliases</a>
809</div>
810<div class="doc_text">
811 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov726d45c2008-03-22 08:36:14 +0000[diff] [blame]812 function, global variable, another alias or bitcast of global value). Aliases
813 may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]814 optional <a href="#visibility">visibility style</a>.</p>
815
816 <h5>Syntax:</h5>
817
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]818<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]819<pre>
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]820@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]821</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]822</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]823
824</div>
825
826
827
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]828<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]829<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
830<div class="doc_text">
831 <p>The return type and each parameter of a function type may have a set of
832 <i>parameter attributes</i> associated with them. Parameter attributes are
833 used to communicate additional information about the result or parameters of
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]834 a function. Parameter attributes are considered to be part of the function,
835 not of the function type, so functions with different parameter attributes
836 can have the same function type.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]837
Reid Spencer950e9f82007-01-15 18:27:39 +0000[diff] [blame]838 <p>Parameter attributes are simple keywords that follow the type specified. If
839 multiple parameter attributes are needed, they are space separated. For
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]840 example:</p>
841
842<div class="doc_code">
843<pre>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]844declare i32 @printf(i8* noalias , ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]845declare i32 @atoi(i8 zeroext)
846declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]847</pre>
848</div>
849
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]850 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
851 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]852
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]853 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]854 <dl>
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]855 <dt><tt>zeroext</tt></dt>
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]856 <dd>This indicates to the code generator that the parameter or return value
857 should be zero-extended to a 32-bit value by the caller (for a parameter)
858 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]859
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]860 <dt><tt>signext</tt></dt>
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]861 <dd>This indicates to the code generator that the parameter or return value
862 should be sign-extended to a 32-bit value by the caller (for a parameter)
863 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]864
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]865 <dt><tt>inreg</tt></dt>
Dale Johannesenc9c6da62008-09-25 20:47:45 +0000[diff] [blame]866 <dd>This indicates that this parameter or return value should be treated
867 in a special target-dependent fashion during while emitting code for a
868 function call or return (usually, by putting it in a register as opposed
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]869 to memory, though some targets use it to distinguish between two different
870 kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]871
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]872 <dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner0747baa2008-01-15 04:34:22 +0000[diff] [blame]873 <dd>This indicates that the pointer parameter should really be passed by
874 value to the function. The attribute implies that a hidden copy of the
875 pointee is made between the caller and the callee, so the callee is unable
Chris Lattnerebec6782008-08-05 18:21:08 +0000[diff] [blame]876 to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner0747baa2008-01-15 04:34:22 +0000[diff] [blame]877 pointer arguments. It is generally used to pass structs and arrays by
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]878 value, but is also valid on pointers to scalars. The copy is considered to
879 belong to the caller not the callee (for example,
880 <tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]881 <tt>byval</tt> parameters). This is not a valid attribute for return
882 values. </dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]883
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]884 <dt><tt>sret</tt></dt>
Duncan Sandse26dec62008-02-18 04:19:38 +0000[diff] [blame]885 <dd>This indicates that the pointer parameter specifies the address of a
886 structure that is the return value of the function in the source program.
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]887 This pointer must be guaranteed by the caller to be valid: loads and stores
888 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]889 be applied to the first parameter. This is not a valid attribute for
890 return values. </dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]891
Zhou Shengfebca342007-06-05 05:28:26 +0000[diff] [blame]892 <dt><tt>noalias</tt></dt>
Nick Lewycky02ff3082008-11-24 03:41:24 +0000[diff] [blame]893 <dd>This indicates that the pointer does not alias any global or any other
894 parameter. The caller is responsible for ensuring that this is the
Nick Lewyckyb2b32fd2008-11-24 05:00:44 +0000[diff] [blame]895 case. On a function return value, <tt>noalias</tt> additionally indicates
896 that the pointer does not alias any other pointers visible to the
Torok Edwin96826072008-11-24 08:02:24 +0000[diff] [blame]897 caller. Note that this applies only to pointers that can be used to actually
898 load/store a value: NULL, unique pointers from malloc(0), and freed pointers
899 are considered to not alias anything.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]900
Duncan Sands50f19f52007-07-27 19:57:41 +0000[diff] [blame]901 <dt><tt>nest</tt></dt>
Duncan Sands0789b8b2008-07-08 09:27:25 +0000[diff] [blame]902 <dd>This indicates that the pointer parameter can be excised using the
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]903 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
904 attribute for return values.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]905 </dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]906
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]907</div>
908
909<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]910<div class="doc_subsection">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]911 <a name="gc">Garbage Collector Names</a>
912</div>
913
914<div class="doc_text">
915<p>Each function may specify a garbage collector name, which is simply a
916string.</p>
917
918<div class="doc_code"><pre
919>define void @f() gc "name" { ...</pre></div>
920
921<p>The compiler declares the supported values of <i>name</i>. Specifying a
922collector which will cause the compiler to alter its output in order to support
923the named garbage collection algorithm.</p>
924</div>
925
926<!-- ======================================================================= -->
927<div class="doc_subsection">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]928 <a name="fnattrs">Function Attributes</a>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]929</div>
930
931<div class="doc_text">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]932
933<p>Function attributes are set to communicate additional information about
934 a function. Function attributes are considered to be part of the function,
935 not of the function type, so functions with different parameter attributes
936 can have the same function type.</p>
937
938 <p>Function attributes are simple keywords that follow the type specified. If
939 multiple attributes are needed, they are space separated. For
940 example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]941
942<div class="doc_code">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]943<pre>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]944define void @f() noinline { ... }
945define void @f() alwaysinline { ... }
946define void @f() alwaysinline optsize { ... }
947define void @f() optsize
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]948</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]949</div>
950
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]951<dl>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]952<dt><tt>alwaysinline</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]953<dd>This attribute indicates that the inliner should attempt to inline this
954function into callers whenever possible, ignoring any active inlining size
955threshold for this caller.</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>noinline</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]958<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner94b5f7d2008-10-05 17:14:59 +0000[diff] [blame]959in any situation. This attribute may not be used together with the
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]960<tt>alwaysinline</tt> attribute.</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>optsize</tt></dt>
Devang Patel66c6c652008-09-29 18:34:44 +0000[diff] [blame]963<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]964make choices that keep the code size of this function low, and otherwise do
965optimizations specifically to reduce code size.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]966
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]967<dt><tt>noreturn</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]968<dd>This function attribute indicates that the function never returns normally.
969This produces undefined behavior at runtime if the function ever does
970dynamically return.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]971
972<dt><tt>nounwind</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]973<dd>This function attribute indicates that the function never returns with an
974unwind or exceptional control flow. If the function does unwind, its runtime
975behavior is undefined.</dd>
976
977<dt><tt>readnone</tt></dt>
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]978<dd>This attribute indicates that the function computes its result (or the
979exception it throws) based strictly on its arguments, without dereferencing any
980pointer arguments or otherwise accessing any mutable state (e.g. memory, control
981registers, etc) visible to caller functions. It does not write through any
982pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
983never changes any state visible to callers.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]984
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]985<dt><tt><a name="readonly">readonly</a></tt></dt>
986<dd>This attribute indicates that the function does not write through any
987pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
988or otherwise modify any state (e.g. memory, control registers, etc) visible to
989caller functions. It may dereference pointer arguments and read state that may
990be set in the caller. A readonly function always returns the same value (or
991throws the same exception) when called with the same set of arguments and global
992state.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]993
994<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame^]995<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]996protector. It is in the form of a "canary"&mdash;a random value placed on the
997stack before the local variables that's checked upon return from the function to
998see if it has been overwritten. A heuristic is used to determine if a function
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame^]999needs stack protectors or not.
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1000
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1001<p>If a function that has an <tt>ssp</tt> attribute is inlined into a function
1002that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
1003have an <tt>ssp</tt> attribute.</p></dd>
1004
1005<dt><tt>sspreq</tt></dt>
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame^]1006<dd>This attribute indicates that the function should <em>always</em> emit a
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1007stack smashing protector. This overrides the <tt><a href="#ssp">ssp</a></tt>
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame^]1008function attribute.
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1009
1010<p>If a function that has an <tt>sspreq</tt> attribute is inlined into a
1011function that doesn't have an <tt>sspreq</tt> attribute or which has
1012an <tt>ssp</tt> attribute, then the resulting function will have
1013an <tt>sspreq</tt> attribute.</p></dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1014</dl>
1015
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1016</div>
1017
1018<!-- ======================================================================= -->
1019<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1020 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1021</div>
1022
1023<div class="doc_text">
1024<p>
1025Modules may contain "module-level inline asm" blocks, which corresponds to the
1026GCC "file scope inline asm" blocks. These blocks are internally concatenated by
1027LLVM and treated as a single unit, but may be separated in the .ll file if
1028desired. The syntax is very simple:
1029</p>
1030
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1031<div class="doc_code">
1032<pre>
1033module asm "inline asm code goes here"
1034module asm "more can go here"
1035</pre>
1036</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1037
1038<p>The strings can contain any character by escaping non-printable characters.
1039 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
1040 for the number.
1041</p>
1042
1043<p>
1044 The inline asm code is simply printed to the machine code .s file when
1045 assembly code is generated.
1046</p>
1047</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1048
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1049<!-- ======================================================================= -->
1050<div class="doc_subsection">
1051 <a name="datalayout">Data Layout</a>
1052</div>
1053
1054<div class="doc_text">
1055<p>A module may specify a target specific data layout string that specifies how
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]1056data is to be laid out in memory. The syntax for the data layout is simply:</p>
1057<pre> target datalayout = "<i>layout specification</i>"</pre>
1058<p>The <i>layout specification</i> consists of a list of specifications
1059separated by the minus sign character ('-'). Each specification starts with a
1060letter and may include other information after the letter to define some
1061aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1062<dl>
1063 <dt><tt>E</tt></dt>
1064 <dd>Specifies that the target lays out data in big-endian form. That is, the
1065 bits with the most significance have the lowest address location.</dd>
1066 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1067 <dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1068 the bits with the least significance have the lowest address location.</dd>
1069 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1070 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
1071 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
1072 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
1073 too.</dd>
1074 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1075 <dd>This specifies the alignment for an integer type of a given bit
1076 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1077 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1078 <dd>This specifies the alignment for a vector type of a given bit
1079 <i>size</i>.</dd>
1080 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1081 <dd>This specifies the alignment for a floating point type of a given bit
1082 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1083 (double).</dd>
1084 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1085 <dd>This specifies the alignment for an aggregate type of a given bit
1086 <i>size</i>.</dd>
1087</dl>
1088<p>When constructing the data layout for a given target, LLVM starts with a
1089default set of specifications which are then (possibly) overriden by the
1090specifications in the <tt>datalayout</tt> keyword. The default specifications
1091are given in this list:</p>
1092<ul>
1093 <li><tt>E</tt> - big endian</li>
1094 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1095 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1096 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1097 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1098 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1099 <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]1100 alignment of 64-bits</li>
1101 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1102 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1103 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1104 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1105 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
1106</ul>
Chris Lattnerebec6782008-08-05 18:21:08 +0000[diff] [blame]1107<p>When LLVM is determining the alignment for a given type, it uses the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1108following rules:</p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1109<ol>
1110 <li>If the type sought is an exact match for one of the specifications, that
1111 specification is used.</li>
1112 <li>If no match is found, and the type sought is an integer type, then the
1113 smallest integer type that is larger than the bitwidth of the sought type is
1114 used. If none of the specifications are larger than the bitwidth then the the
1115 largest integer type is used. For example, given the default specifications
1116 above, the i7 type will use the alignment of i8 (next largest) while both
1117 i65 and i256 will use the alignment of i64 (largest specified).</li>
1118 <li>If no match is found, and the type sought is a vector type, then the
1119 largest vector type that is smaller than the sought vector type will be used
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1120 as a fall back. This happens because &lt;128 x double&gt; can be implemented
1121 in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1122</ol>
1123</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1124
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1125<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1126<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1127<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1128
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1129<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1130
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1131<p>The LLVM type system is one of the most important features of the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1132intermediate representation. Being typed enables a number of
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1133optimizations to be performed on the intermediate representation directly,
1134without having to do
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1135extra analyses on the side before the transformation. A strong type
1136system makes it easier to read the generated code and enables novel
1137analyses and transformations that are not feasible to perform on normal
1138three address code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1139
1140</div>
1141
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1142<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1143<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1144Classifications</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1145<div class="doc_text">
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1146<p>The types fall into a few useful
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1147classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1148
1149<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1150 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1151 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1152 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1153 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1154 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1155 </tr>
1156 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1157 <td><a href="#t_floating">floating point</a></td>
1158 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1159 </tr>
1160 <tr>
1161 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1162 <td><a href="#t_integer">integer</a>,
1163 <a href="#t_floating">floating point</a>,
1164 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1165 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1166 <a href="#t_struct">structure</a>,
1167 <a href="#t_array">array</a>,
Dan Gohmanade5faa2008-05-23 22:50:26 +0000[diff] [blame]1168 <a href="#t_label">label</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1169 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1170 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1171 <tr>
1172 <td><a href="#t_primitive">primitive</a></td>
1173 <td><a href="#t_label">label</a>,
1174 <a href="#t_void">void</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1175 <a href="#t_floating">floating point</a>.</td>
1176 </tr>
1177 <tr>
1178 <td><a href="#t_derived">derived</a></td>
1179 <td><a href="#t_integer">integer</a>,
1180 <a href="#t_array">array</a>,
1181 <a href="#t_function">function</a>,
1182 <a href="#t_pointer">pointer</a>,
1183 <a href="#t_struct">structure</a>,
1184 <a href="#t_pstruct">packed structure</a>,
1185 <a href="#t_vector">vector</a>,
1186 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1187 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1188 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1189 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1190</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1191
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1192<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1193most important. Values of these types are the only ones which can be
1194produced by instructions, passed as arguments, or used as operands to
Dan Gohmanc4b49eb2008-05-23 21:53:15 +0000[diff] [blame]1195instructions.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1196</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1197
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1198<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1199<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1200
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1201<div class="doc_text">
1202<p>The primitive types are the fundamental building blocks of the LLVM
1203system.</p>
1204
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1205</div>
1206
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1207<!-- _______________________________________________________________________ -->
1208<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1209
1210<div class="doc_text">
1211 <table>
1212 <tbody>
1213 <tr><th>Type</th><th>Description</th></tr>
1214 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1215 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1216 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1217 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1218 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1219 </tbody>
1220 </table>
1221</div>
1222
1223<!-- _______________________________________________________________________ -->
1224<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1225
1226<div class="doc_text">
1227<h5>Overview:</h5>
1228<p>The void type does not represent any value and has no size.</p>
1229
1230<h5>Syntax:</h5>
1231
1232<pre>
1233 void
1234</pre>
1235</div>
1236
1237<!-- _______________________________________________________________________ -->
1238<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1239
1240<div class="doc_text">
1241<h5>Overview:</h5>
1242<p>The label type represents code labels.</p>
1243
1244<h5>Syntax:</h5>
1245
1246<pre>
1247 label
1248</pre>
1249</div>
1250
1251
1252<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1253<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1254
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1255<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1256
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1257<p>The real power in LLVM comes from the derived types in the system.
1258This is what allows a programmer to represent arrays, functions,
1259pointers, and other useful types. Note that these derived types may be
1260recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1261
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1262</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1263
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1264<!-- _______________________________________________________________________ -->
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1265<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1266
1267<div class="doc_text">
1268
1269<h5>Overview:</h5>
1270<p>The integer type is a very simple derived type that simply specifies an
1271arbitrary bit width for the integer type desired. Any bit width from 1 bit to
12722^23-1 (about 8 million) can be specified.</p>
1273
1274<h5>Syntax:</h5>
1275
1276<pre>
1277 iN
1278</pre>
1279
1280<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1281value.</p>
1282
1283<h5>Examples:</h5>
1284<table class="layout">
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]1285 <tbody>
1286 <tr>
1287 <td><tt>i1</tt></td>
1288 <td>a single-bit integer.</td>
1289 </tr><tr>
1290 <td><tt>i32</tt></td>
1291 <td>a 32-bit integer.</td>
1292 </tr><tr>
1293 <td><tt>i1942652</tt></td>
1294 <td>a really big integer of over 1 million bits.</td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1295 </tr>
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]1296 </tbody>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1297</table>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1298</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1299
1300<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1301<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1302
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1303<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1304
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1305<h5>Overview:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1306
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1307<p>The array type is a very simple derived type that arranges elements
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1308sequentially in memory. The array type requires a size (number of
1309elements) and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1310
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1311<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1312
1313<pre>
1314 [&lt;# elements&gt; x &lt;elementtype&gt;]
1315</pre>
1316
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1317<p>The number of elements is a constant integer value; elementtype may
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1318be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1319
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1320<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1321<table class="layout">
1322 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1323 <td class="left"><tt>[40 x i32]</tt></td>
1324 <td class="left">Array of 40 32-bit integer values.</td>
1325 </tr>
1326 <tr class="layout">
1327 <td class="left"><tt>[41 x i32]</tt></td>
1328 <td class="left">Array of 41 32-bit integer values.</td>
1329 </tr>
1330 <tr class="layout">
1331 <td class="left"><tt>[4 x i8]</tt></td>
1332 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1333 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1334</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1335<p>Here are some examples of multidimensional arrays:</p>
1336<table class="layout">
1337 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1338 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1339 <td class="left">3x4 array of 32-bit integer values.</td>
1340 </tr>
1341 <tr class="layout">
1342 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1343 <td class="left">12x10 array of single precision floating point values.</td>
1344 </tr>
1345 <tr class="layout">
1346 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1347 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1348 </tr>
1349</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1350
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1351<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1352length array. Normally, accesses past the end of an array are undefined in
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1353LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1354As a special case, however, zero length arrays are recognized to be variable
1355length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1356type "{ i32, [0 x float]}", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1357
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1358</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1359
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1360<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1361<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1362<div class="doc_text">
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1363
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1364<h5>Overview:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1365
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1366<p>The function type can be thought of as a function signature. It
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1367consists of a return type and a list of formal parameter types. The
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1368return 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]1369If 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]1370class types, and the struct must have at least one element.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1371
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1372<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1373
1374<pre>
1375 &lt;returntype list&gt; (&lt;parameter list&gt;)
1376</pre>
1377
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1378<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]1379specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1380which indicates that the function takes a variable number of arguments.
1381Variable argument functions can access their arguments with the <a
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1382 href="#int_varargs">variable argument handling intrinsic</a> functions.
1383'<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1384<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1385
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1386<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1387<table class="layout">
1388 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1389 <td class="left"><tt>i32 (i32)</tt></td>
1390 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1391 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1392 </tr><tr class="layout">
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]1393 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1394 </tt></td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1395 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1396 an <tt>i16</tt> that should be sign extended and a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1397 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1398 <tt>float</tt>.
1399 </td>
1400 </tr><tr class="layout">
1401 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1402 <td class="left">A vararg function that takes at least one
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1403 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1404 which returns an integer. This is the signature for <tt>printf</tt> in
1405 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1406 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1407 </tr><tr class="layout">
1408 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Devang Patel3a5bff82008-03-24 18:10:52 +0000[diff] [blame]1409 <td class="left">A function taking an <tt>i32></tt>, returning two
1410 <tt> i32 </tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1411 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1412 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1413</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1414
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1415</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1416<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1417<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1418<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1419<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1420<p>The structure type is used to represent a collection of data members
1421together in memory. The packing of the field types is defined to match
1422the ABI of the underlying processor. The elements of a structure may
1423be any type that has a size.</p>
1424<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1425and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1426field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1427instruction.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1428<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1429<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1430<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1431<table class="layout">
1432 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1433 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1434 <td class="left">A triple of three <tt>i32</tt> values</td>
1435 </tr><tr class="layout">
1436 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1437 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1438 second element is a <a href="#t_pointer">pointer</a> to a
1439 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1440 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1441 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1442</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1443</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1444
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1445<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1446<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1447</div>
1448<div class="doc_text">
1449<h5>Overview:</h5>
1450<p>The packed structure type is used to represent a collection of data members
1451together in memory. There is no padding between fields. Further, the alignment
1452of a packed structure is 1 byte. The elements of a packed structure may
1453be any type that has a size.</p>
1454<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1455and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1456field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1457instruction.</p>
1458<h5>Syntax:</h5>
1459<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1460<h5>Examples:</h5>
1461<table class="layout">
1462 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1463 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1464 <td class="left">A triple of three <tt>i32</tt> values</td>
1465 </tr><tr class="layout">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1466 <td class="left">
1467<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1468 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1469 second element is a <a href="#t_pointer">pointer</a> to a
1470 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1471 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1472 </tr>
1473</table>
1474</div>
1475
1476<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1477<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1478<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1479<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1480<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]1481reference to another object, which must live in memory. Pointer types may have
1482an optional address space attribute defining the target-specific numbered
1483address space where the pointed-to object resides. The default address space is
1484zero.</p>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1485<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1486<pre> &lt;type&gt; *<br></pre>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1487<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1488<table class="layout">
1489 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1490 <td class="left"><tt>[4x i32]*</tt></td>
1491 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1492 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1493 </tr>
1494 <tr class="layout">
1495 <td class="left"><tt>i32 (i32 *) *</tt></td>
1496 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1497 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1498 <tt>i32</tt>.</td>
1499 </tr>
1500 <tr class="layout">
1501 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1502 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1503 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1504 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1505</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1506</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1507
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1508<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1509<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1510<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1511
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1512<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1513
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1514<p>A vector type is a simple derived type that represents a vector
1515of elements. Vector types are used when multiple primitive data
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1516are operated in parallel using a single instruction (SIMD).
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1517A vector type requires a size (number of
Chris Lattnerb8d172f2005-11-10 01:44:22 +0000[diff] [blame]1518elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1519of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1520considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1521
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1522<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1523
1524<pre>
1525 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1526</pre>
1527
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1528<p>The number of elements is a constant integer value; elementtype may
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1529be any integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1530
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1531<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1532
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1533<table class="layout">
1534 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1535 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1536 <td class="left">Vector of 4 32-bit integer values.</td>
1537 </tr>
1538 <tr class="layout">
1539 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1540 <td class="left">Vector of 8 32-bit floating-point values.</td>
1541 </tr>
1542 <tr class="layout">
1543 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1544 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1545 </tr>
1546</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1547</div>
1548
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1549<!-- _______________________________________________________________________ -->
1550<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1551<div class="doc_text">
1552
1553<h5>Overview:</h5>
1554
1555<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksen8ac04ff2007-10-14 00:34:53 +0000[diff] [blame]1556corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1557In LLVM, opaque types can eventually be resolved to any type (not just a
1558structure type).</p>
1559
1560<h5>Syntax:</h5>
1561
1562<pre>
1563 opaque
1564</pre>
1565
1566<h5>Examples:</h5>
1567
1568<table class="layout">
1569 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1570 <td class="left"><tt>opaque</tt></td>
1571 <td class="left">An opaque type.</td>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1572 </tr>
1573</table>
1574</div>
1575
1576
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1577<!-- *********************************************************************** -->
1578<div class="doc_section"> <a name="constants">Constants</a> </div>
1579<!-- *********************************************************************** -->
1580
1581<div class="doc_text">
1582
1583<p>LLVM has several different basic types of constants. This section describes
1584them all and their syntax.</p>
1585
1586</div>
1587
1588<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1589<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1590
1591<div class="doc_text">
1592
1593<dl>
1594 <dt><b>Boolean constants</b></dt>
1595
1596 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1597 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1598 </dd>
1599
1600 <dt><b>Integer constants</b></dt>
1601
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1602 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1603 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1604 integer types.
1605 </dd>
1606
1607 <dt><b>Floating point constants</b></dt>
1608
1609 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1610 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]1611 notation (see below). The assembler requires the exact decimal value of
1612 a floating-point constant. For example, the assembler accepts 1.25 but
1613 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1614 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1615
1616 <dt><b>Null pointer constants</b></dt>
1617
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1618 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1619 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1620
1621</dl>
1622
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1623<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1624of floating point constants. For example, the form '<tt>double
16250x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
16264.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1627(and the only time that they are generated by the disassembler) is when a
1628floating point constant must be emitted but it cannot be represented as a
1629decimal floating point number. For example, NaN's, infinities, and other
1630special values are represented in their IEEE hexadecimal format so that
1631assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1632
1633</div>
1634
1635<!-- ======================================================================= -->
1636<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1637</div>
1638
1639<div class="doc_text">
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]1640<p>Aggregate constants arise from aggregation of simple constants
1641and smaller aggregate constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1642
1643<dl>
1644 <dt><b>Structure constants</b></dt>
1645
1646 <dd>Structure constants are represented with notation similar to structure
1647 type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner64910ee2007-12-25 20:34:52 +0000[diff] [blame]1648 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1649 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]1650 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1651 types of elements must match those specified by the type.
1652 </dd>
1653
1654 <dt><b>Array constants</b></dt>
1655
1656 <dd>Array constants are represented with notation similar to array type
1657 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1658 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1659 constants must have <a href="#t_array">array type</a>, and the number and
1660 types of elements must match those specified by the type.
1661 </dd>
1662
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1663 <dt><b>Vector constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1664
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1665 <dd>Vector constants are represented with notation similar to vector type
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1666 definitions (a comma separated list of elements, surrounded by
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1667 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]1668 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1669 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1670 match those specified by the type.
1671 </dd>
1672
1673 <dt><b>Zero initialization</b></dt>
1674
1675 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1676 value to zero of <em>any</em> type, including scalar and aggregate types.
1677 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]1678 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1679 initializers.
1680 </dd>
1681</dl>
1682
1683</div>
1684
1685<!-- ======================================================================= -->
1686<div class="doc_subsection">
1687 <a name="globalconstants">Global Variable and Function Addresses</a>
1688</div>
1689
1690<div class="doc_text">
1691
1692<p>The addresses of <a href="#globalvars">global variables</a> and <a
1693href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1694constants. These constants are explicitly referenced when the <a
1695href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1696href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1697file:</p>
1698
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1699<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1700<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]1701@X = global i32 17
1702@Y = global i32 42
1703@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1704</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1705</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1706
1707</div>
1708
1709<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1710<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1711<div class="doc_text">
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1712 <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]1713 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1714 a constant is permitted.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1715
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1716 <p>Undefined values indicate to the compiler that the program is well defined
1717 no matter what value is used, giving the compiler more freedom to optimize.
1718 </p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1719</div>
1720
1721<!-- ======================================================================= -->
1722<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1723</div>
1724
1725<div class="doc_text">
1726
1727<p>Constant expressions are used to allow expressions involving other constants
1728to be used as constants. Constant expressions may be of any <a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1729href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1730that does not have side effects (e.g. load and call are not supported). The
1731following is the syntax for constant expressions:</p>
1732
1733<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1734 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1735 <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]1736 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1737
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1738 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1739 <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]1740 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]1741
1742 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1743 <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]1744 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]1745
1746 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1747 <dd>Truncate a floating point constant to another floating point type. The
1748 size of CST must be larger than the size of TYPE. Both types must be
1749 floating point.</dd>
1750
1751 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1752 <dd>Floating point extend a constant to another type. The size of CST must be
1753 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1754
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]1755 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1756 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1757 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1758 or vector floating point 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 integer type,
1760 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>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1763 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1764 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1765 or vector floating point 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 integer type,
1767 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1768
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1769 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1770 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1771 constant. TYPE must be a scalar or vector floating point type. CST must be of
1772 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1773 of the same number of elements. If the value won't fit in the floating point
1774 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1775
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1776 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1777 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1778 constant. TYPE must be a scalar or vector floating point type. CST must be of
1779 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1780 of the same number of elements. If the value won't fit in the floating point
1781 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1782
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1783 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1784 <dd>Convert a pointer typed constant to the corresponding integer constant
1785 TYPE must be an integer type. CST must be of pointer type. The CST value is
1786 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1787
1788 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1789 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1790 pointer type. CST must be of integer type. The CST value is zero extended,
1791 truncated, or unchanged to make it fit in a pointer size. This one is
1792 <i>really</i> dangerous!</dd>
1793
1794 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1795 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1796 identical (same number of bits). The conversion is done as if the CST value
1797 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]1798 with this operator, just the type. This can be used for conversion of
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1799 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]1800 pointers it is only valid to cast to another pointer type. It is not valid
1801 to bitcast to or from an aggregate type.
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1802 </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1803
1804 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1805
1806 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1807 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1808 instruction, the index list may have zero or more indexes, which are required
1809 to make sense for the type of "CSTPTR".</dd>
1810
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1811 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1812
1813 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1814 constants.</dd>
1815
1816 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1817 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1818
1819 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1820 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1821
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]1822 <dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
1823 <dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
1824
1825 <dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
1826 <dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
1827
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1828 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1829
1830 <dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1831 operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1832
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1833 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1834
1835 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1836 operation</a> on constants.</dd>
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1837
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1838
1839 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1840
1841 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1842 operation</a> on constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1843
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1844 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1845
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1846 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1847 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1848 binary</a> operations. The constraints on operands are the same as those for
1849 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1850 values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1851</dl>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1852</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]1853
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1854<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1855<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1856<!-- *********************************************************************** -->
1857
1858<!-- ======================================================================= -->
1859<div class="doc_subsection">
1860<a name="inlineasm">Inline Assembler Expressions</a>
1861</div>
1862
1863<div class="doc_text">
1864
1865<p>
1866LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1867Module-Level Inline Assembly</a>) through the use of a special value. This
1868value represents the inline assembler as a string (containing the instructions
1869to emit), a list of operand constraints (stored as a string), and a flag that
1870indicates whether or not the inline asm expression has side effects. An example
1871inline assembler expression is:
1872</p>
1873
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1874<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1875<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1876i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1877</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1878</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1879
1880<p>
1881Inline assembler expressions may <b>only</b> be used as the callee operand of
1882a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
1883</p>
1884
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1885<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1886<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1887%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]1888</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1889</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1890
1891<p>
1892Inline asms with side effects not visible in the constraint list must be marked
1893as having side effects. This is done through the use of the
1894'<tt>sideeffect</tt>' keyword, like so:
1895</p>
1896
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1897<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1898<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1899call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1900</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1901</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1902
1903<p>TODO: The format of the asm and constraints string still need to be
1904documented here. Constraints on what can be done (e.g. duplication, moving, etc
Chris Lattner4f993352008-10-04 18:36:02 +0000[diff] [blame]1905need to be documented). This is probably best done by reference to another
1906document that covers inline asm from a holistic perspective.
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1907</p>
1908
1909</div>
1910
1911<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1912<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
1913<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1914
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1915<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1916
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1917<p>The LLVM instruction set consists of several different
1918classifications of instructions: <a href="#terminators">terminator
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1919instructions</a>, <a href="#binaryops">binary instructions</a>,
1920<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1921 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
1922instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1923
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1924</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1925
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1926<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1927<div class="doc_subsection"> <a name="terminators">Terminator
1928Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1929
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1930<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1931
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1932<p>As mentioned <a href="#functionstructure">previously</a>, every
1933basic block in a program ends with a "Terminator" instruction, which
1934indicates which block should be executed after the current block is
1935finished. These terminator instructions typically yield a '<tt>void</tt>'
1936value: they produce control flow, not values (the one exception being
1937the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1938<p>There are six different terminator instructions: the '<a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1939 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
1940instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1941the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
1942 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
1943 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1944
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1945</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1946
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1947<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1948<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
1949Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1950<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1951<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]1952<pre>
1953 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]1954 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1955</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1956
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1957<h5>Overview:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1958
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]1959<p>The '<tt>ret</tt>' instruction is used to return control flow (and
1960optionally a value) from a function back to the caller.</p>
John Criswell4457dc92004-04-09 16:48:45 +0000[diff] [blame]1961<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]1962returns a value and then causes control flow, and one that just causes
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1963control flow to occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1964
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1965<h5>Arguments:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1966
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]1967<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
1968the return value. The type of the return value must be a
1969'<a href="#t_firstclass">first class</a>' type.</p>
1970
1971<p>A function is not <a href="#wellformed">well formed</a> if
1972it it has a non-void return type and contains a '<tt>ret</tt>'
1973instruction with no return value or a return value with a type that
1974does not match its type, or if it has a void return type and contains
1975a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1976
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1977<h5>Semantics:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1978
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1979<p>When the '<tt>ret</tt>' instruction is executed, control flow
1980returns back to the calling function's context. If the caller is a "<a
John Criswellfa081872004-06-25 15:16:57 +0000[diff] [blame]1981 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1982the instruction after the call. If the caller was an "<a
1983 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1984at the beginning of the "normal" destination block. If the instruction
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1985returns a value, that value shall set the call or invoke instruction's
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1986return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1987
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1988<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1989
1990<pre>
1991 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1992 ret void <i>; Return from a void function</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]1993 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]1994</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1995</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1996<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1997<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1998<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1999<h5>Syntax:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2000<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]2001</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2002<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2003<p>The '<tt>br</tt>' instruction is used to cause control flow to
2004transfer to a different basic block in the current function. There are
2005two forms of this instruction, corresponding to a conditional branch
2006and an unconditional branch.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2007<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2008<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2009single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]2010unconditional form of the '<tt>br</tt>' instruction takes a single
2011'<tt>label</tt>' value as a target.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2012<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2013<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2014argument is evaluated. If the value is <tt>true</tt>, control flows
2015to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2016control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2017<h5>Example:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2018<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]2019 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]2020</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2021<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2022<div class="doc_subsubsection">
2023 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2024</div>
2025
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2026<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2027<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2028
2029<pre>
2030 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2031</pre>
2032
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2033<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2034
2035<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
2036several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2037instruction, allowing a branch to occur to one of many possible
2038destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2039
2040
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2041<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2042
2043<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
2044comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
2045an array of pairs of comparison value constants and '<tt>label</tt>'s. The
2046table is not allowed to contain duplicate constant entries.</p>
2047
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2048<h5>Semantics:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2049
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2050<p>The <tt>switch</tt> instruction specifies a table of values and
2051destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]2052table is searched for the given value. If the value is found, control flow is
2053transfered to the corresponding destination; otherwise, control flow is
2054transfered to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2055
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2056<h5>Implementation:</h5>
2057
2058<p>Depending on properties of the target machine and the particular
2059<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]2060ways. For example, it could be generated as a series of chained conditional
2061branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2062
2063<h5>Example:</h5>
2064
2065<pre>
2066 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2067 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2068 switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2069
2070 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2071 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2072
2073 <i>; Implement a jump table:</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2074 switch i32 %val, label %otherwise [ i32 0, label %onzero
2075 i32 1, label %onone
2076 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2077</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2078</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2079
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2080<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2081<div class="doc_subsubsection">
2082 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2083</div>
2084
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2085<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2086
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2087<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2088
2089<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2090 &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]2091 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2092</pre>
2093
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2094<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2095
2096<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
2097function, with the possibility of control flow transfer to either the
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2098'<tt>normal</tt>' label or the
2099'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2100"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
2101"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2102href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]2103continued at the dynamically nearest "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2104
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2105<h5>Arguments:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2106
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2107<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2108
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2109<ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2110 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]2111 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2112 convention</a> the call should use. If none is specified, the call defaults
2113 to using C calling conventions.
2114 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2115
2116 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
2117 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
2118 and '<tt>inreg</tt>' attributes are valid here.</li>
2119
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2120 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
2121 function value being invoked. In most cases, this is a direct function
2122 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
2123 an arbitrary pointer to function value.
2124 </li>
2125
2126 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
2127 function to be invoked. </li>
2128
2129 <li>'<tt>function args</tt>': argument list whose types match the function
2130 signature argument types. If the function signature indicates the function
2131 accepts a variable number of arguments, the extra arguments can be
2132 specified. </li>
2133
2134 <li>'<tt>normal label</tt>': the label reached when the called function
2135 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
2136
2137 <li>'<tt>exception label</tt>': the label reached when a callee returns with
2138 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
2139
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2140 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2141 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2142 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2143</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2144
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2145<h5>Semantics:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2146
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2147<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2148href="#i_call">call</a></tt>' instruction in most regards. The primary
2149difference is that it establishes an association with a label, which is used by
2150the runtime library to unwind the stack.</p>
2151
2152<p>This instruction is used in languages with destructors to ensure that proper
2153cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2154exception. Additionally, this is important for implementation of
2155'<tt>catch</tt>' clauses in high-level languages that support them.</p>
2156
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2157<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2158<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2159 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2160 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2161 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2162 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2163</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2164</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2165
2166
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2167<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2168
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2169<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2170Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2171
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2172<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2173
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2174<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2175<pre>
2176 unwind
2177</pre>
2178
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2179<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2180
2181<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
2182at the first callee in the dynamic call stack which used an <a
2183href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
2184primarily used to implement exception handling.</p>
2185
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2186<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2187
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]2188<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2189immediately halt. The dynamic call stack is then searched for the first <a
2190href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
2191execution continues at the "exceptional" destination block specified by the
2192<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
2193dynamic call chain, undefined behavior results.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2194</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2195
2196<!-- _______________________________________________________________________ -->
2197
2198<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2199Instruction</a> </div>
2200
2201<div class="doc_text">
2202
2203<h5>Syntax:</h5>
2204<pre>
2205 unreachable
2206</pre>
2207
2208<h5>Overview:</h5>
2209
2210<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
2211instruction is used to inform the optimizer that a particular portion of the
2212code is not reachable. This can be used to indicate that the code after a
2213no-return function cannot be reached, and other facts.</p>
2214
2215<h5>Semantics:</h5>
2216
2217<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
2218</div>
2219
2220
2221
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2222<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2223<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2224<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2225<p>Binary operators are used to do most of the computation in a
Chris Lattner5a158142008-04-01 18:47:32 +0000[diff] [blame]2226program. They require two operands of the same type, execute an operation on them, and
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2227produce a single value. The operands might represent
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2228multiple 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]2229The result value has the same type as its operands.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2230<p>There are several different binary operators:</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2231</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2232<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2233<div class="doc_subsubsection">
2234 <a name="i_add">'<tt>add</tt>' Instruction</a>
2235</div>
2236
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2237<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2238
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2239<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2240
2241<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2242 &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]2243</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2244
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2245<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2246
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2247<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2248
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2249<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2250
2251<p>The two arguments to the '<tt>add</tt>' instruction must be <a
2252 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
2253 <a href="#t_vector">vector</a> values. Both arguments must have identical
2254 types.</p>
2255
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2256<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2257
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2258<p>The value produced is the integer or floating point sum of the two
2259operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2260
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2261<p>If an integer sum has unsigned overflow, the result returned is the
2262mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2263the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2264
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2265<p>Because LLVM integers use a two's complement representation, this
2266instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2267
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2268<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2269
2270<pre>
2271 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2272</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2273</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2274<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2275<div class="doc_subsubsection">
2276 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2277</div>
2278
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2279<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2280
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2281<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2282
2283<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2284 &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]2285</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2286
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2287<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2288
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2289<p>The '<tt>sub</tt>' instruction returns the difference of its two
2290operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2291
2292<p>Note that the '<tt>sub</tt>' instruction is used to represent the
2293'<tt>neg</tt>' instruction present in most other intermediate
2294representations.</p>
2295
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2296<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2297
2298<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
2299 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2300 or <a href="#t_vector">vector</a> values. Both arguments must have identical
2301 types.</p>
2302
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2303<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2304
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2305<p>The value produced is the integer or floating point difference of
2306the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2307
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2308<p>If an integer difference has unsigned overflow, the result returned is the
2309mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2310the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2311
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2312<p>Because LLVM integers use a two's complement representation, this
2313instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2314
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2315<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2316<pre>
2317 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2318 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2319</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2320</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2321
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2322<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2323<div class="doc_subsubsection">
2324 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2325</div>
2326
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2327<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2328
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2329<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2330<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]2331</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2332<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2333<p>The '<tt>mul</tt>' instruction returns the product of its two
2334operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2335
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2336<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2337
2338<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
2339href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2340or <a href="#t_vector">vector</a> values. Both arguments must have identical
2341types.</p>
2342
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2343<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2344
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2345<p>The value produced is the integer or floating point product of the
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2346two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2347
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2348<p>If the result of an integer multiplication has unsigned overflow,
2349the result returned is the mathematical result modulo
23502<sup>n</sup>, where n is the bit width of the result.</p>
2351<p>Because LLVM integers use a two's complement representation, and the
2352result is the same width as the operands, this instruction returns the
2353correct result for both signed and unsigned integers. If a full product
2354(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
2355should be sign-extended or zero-extended as appropriate to the
2356width of the full product.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2357<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2358<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]2359</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2360</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2361
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2362<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2363<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2364</a></div>
2365<div class="doc_text">
2366<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2367<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]2368</pre>
2369<h5>Overview:</h5>
2370<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2371operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2372
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2373<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2374
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2375<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2376<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2377values. Both arguments must have identical types.</p>
2378
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2379<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2380
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2381<p>The value produced is the unsigned integer quotient of the two operands.</p>
2382<p>Note that unsigned integer division and signed integer division are distinct
2383operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2384<p>Division by zero leads to undefined behavior.</p>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2385<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2386<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]2387</pre>
2388</div>
2389<!-- _______________________________________________________________________ -->
2390<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2391</a> </div>
2392<div class="doc_text">
2393<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2394<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2395 &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]2396</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2397
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2398<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2399
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2400<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2401operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2402
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2403<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2404
2405<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2406<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2407values. Both arguments must have identical types.</p>
2408
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2409<h5>Semantics:</h5>
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2410<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]2411<p>Note that signed integer division and unsigned integer division are distinct
2412operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2413<p>Division by zero leads to undefined behavior. Overflow also leads to
2414undefined behavior; this is a rare case, but can occur, for example,
2415by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2416<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2417<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]2418</pre>
2419</div>
2420<!-- _______________________________________________________________________ -->
2421<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2422Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2423<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2424<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2425<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2426 &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]2427</pre>
2428<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2429
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2430<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2431operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2432
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2433<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2434
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2435<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2436<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2437of floating point values. Both arguments must have identical types.</p>
2438
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2439<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2440
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2441<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2442
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2443<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2444
2445<pre>
2446 &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]2447</pre>
2448</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2449
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2450<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2451<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2452</div>
2453<div class="doc_text">
2454<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2455<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]2456</pre>
2457<h5>Overview:</h5>
2458<p>The '<tt>urem</tt>' instruction returns the remainder from the
2459unsigned division of its two arguments.</p>
2460<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2461<p>The two arguments to the '<tt>urem</tt>' instruction must be
2462<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2463values. Both arguments must have identical types.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2464<h5>Semantics:</h5>
2465<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2466This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2467<p>Note that unsigned integer remainder and signed integer remainder are
2468distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
2469<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2470<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2471<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]2472</pre>
2473
2474</div>
2475<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2476<div class="doc_subsubsection">
2477 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
2478</div>
2479
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2480<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2481
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2482<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2483
2484<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2485 &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]2486</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2487
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2488<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2489
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2490<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2491signed division of its two operands. This instruction can also take
2492<a href="#t_vector">vector</a> versions of the values in which case
2493the elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]2494
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2495<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2496
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2497<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2498<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2499values. Both arguments must have identical types.</p>
2500
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2501<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2502
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2503<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2504has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
2505operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2506a value. For more information about the difference, see <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2507 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2508Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencer64f5c6c2007-03-24 22:40:44 +0000[diff] [blame]2509please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2510Wikipedia: modulo operation</a>.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2511<p>Note that signed integer remainder and unsigned integer remainder are
2512distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
2513<p>Taking the remainder of a division by zero leads to undefined behavior.
2514Overflow also leads to undefined behavior; this is a rare case, but can occur,
2515for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
2516(The remainder doesn't actually overflow, but this rule lets srem be
2517implemented using instructions that return both the result of the division
2518and the remainder.)</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2519<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2520<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]2521</pre>
2522
2523</div>
2524<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2525<div class="doc_subsubsection">
2526 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
2527
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2528<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2529
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2530<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2531<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]2532</pre>
2533<h5>Overview:</h5>
2534<p>The '<tt>frem</tt>' instruction returns the remainder from the
2535division of its two operands.</p>
2536<h5>Arguments:</h5>
2537<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2538<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2539of floating point values. Both arguments must have identical types.</p>
2540
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2541<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2542
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2543<p>This instruction returns the <i>remainder</i> of a division.
2544The remainder has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2545
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2546<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2547
2548<pre>
2549 &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]2550</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2551</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]2552
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2553<!-- ======================================================================= -->
2554<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2555Operations</a> </div>
2556<div class="doc_text">
2557<p>Bitwise binary operators are used to do various forms of
2558bit-twiddling in a program. They are generally very efficient
2559instructions and can commonly be strength reduced from other
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2560instructions. They require two operands of the same type, execute an operation on them,
2561and 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]2562</div>
2563
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2564<!-- _______________________________________________________________________ -->
2565<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2566Instruction</a> </div>
2567<div class="doc_text">
2568<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2569<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]2570</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2571
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2572<h5>Overview:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2573
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2574<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2575the left a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2576
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2577<h5>Arguments:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2578
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2579<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2580 href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2581type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2582
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2583<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2584
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2585<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
2586where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
2587equal 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]2588
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2589<h5>Example:</h5><pre>
2590 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2591 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2592 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2593 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2594</pre>
2595</div>
2596<!-- _______________________________________________________________________ -->
2597<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2598Instruction</a> </div>
2599<div class="doc_text">
2600<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2601<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]2602</pre>
2603
2604<h5>Overview:</h5>
2605<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2606operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2607
2608<h5>Arguments:</h5>
2609<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2610<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]2611type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2612
2613<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2614
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2615<p>This instruction always performs a logical shift right operation. The most
2616significant bits of the result will be filled with zero bits after the
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2617shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
2618the number of bits in <tt>op1</tt>, the result is undefined.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2619
2620<h5>Example:</h5>
2621<pre>
2622 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2623 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2624 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2625 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2626 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2627</pre>
2628</div>
2629
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2630<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2631<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2632Instruction</a> </div>
2633<div class="doc_text">
2634
2635<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2636<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]2637</pre>
2638
2639<h5>Overview:</h5>
2640<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2641operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2642
2643<h5>Arguments:</h5>
2644<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2645<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]2646type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2647
2648<h5>Semantics:</h5>
2649<p>This instruction always performs an arithmetic shift right operation,
2650The most significant bits of the result will be filled with the sign bit
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2651of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
2652larger than the number of bits in <tt>op1</tt>, the result is undefined.
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2653</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2654
2655<h5>Example:</h5>
2656<pre>
2657 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2658 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2659 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2660 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2661 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2662</pre>
2663</div>
2664
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2665<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2666<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2667Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2668
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2669<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2670
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2671<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2672
2673<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2674 &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]2675</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2676
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2677<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2678
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2679<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2680its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2681
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2682<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2683
2684<p>The two arguments to the '<tt>and</tt>' instruction must be
2685<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2686values. Both arguments must have identical types.</p>
2687
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2688<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2689<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2690<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2691<div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2692<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2693 <tbody>
2694 <tr>
2695 <td>In0</td>
2696 <td>In1</td>
2697 <td>Out</td>
2698 </tr>
2699 <tr>
2700 <td>0</td>
2701 <td>0</td>
2702 <td>0</td>
2703 </tr>
2704 <tr>
2705 <td>0</td>
2706 <td>1</td>
2707 <td>0</td>
2708 </tr>
2709 <tr>
2710 <td>1</td>
2711 <td>0</td>
2712 <td>0</td>
2713 </tr>
2714 <tr>
2715 <td>1</td>
2716 <td>1</td>
2717 <td>1</td>
2718 </tr>
2719 </tbody>
2720</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2721</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2722<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2723<pre>
2724 &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]2725 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2726 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2727</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2728</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2729<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2730<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2731<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2732<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2733<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]2734</pre>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2735<h5>Overview:</h5>
2736<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2737or of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2738<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2739
2740<p>The two arguments to the '<tt>or</tt>' instruction must be
2741<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2742values. Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2743<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2744<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2745<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2746<div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2747<table border="1" cellspacing="0" cellpadding="4">
2748 <tbody>
2749 <tr>
2750 <td>In0</td>
2751 <td>In1</td>
2752 <td>Out</td>
2753 </tr>
2754 <tr>
2755 <td>0</td>
2756 <td>0</td>
2757 <td>0</td>
2758 </tr>
2759 <tr>
2760 <td>0</td>
2761 <td>1</td>
2762 <td>1</td>
2763 </tr>
2764 <tr>
2765 <td>1</td>
2766 <td>0</td>
2767 <td>1</td>
2768 </tr>
2769 <tr>
2770 <td>1</td>
2771 <td>1</td>
2772 <td>1</td>
2773 </tr>
2774 </tbody>
2775</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2776</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2777<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2778<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2779 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2780 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2781</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2782</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2783<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2784<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2785Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2786<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2787<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2788<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]2789</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2790<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2791<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2792or of its two operands. The <tt>xor</tt> is used to implement the
2793"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2794<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2795<p>The two arguments to the '<tt>xor</tt>' instruction must be
2796<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2797values. Both arguments must have identical types.</p>
2798
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2799<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2800
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2801<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2802<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2803<div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2804<table border="1" cellspacing="0" cellpadding="4">
2805 <tbody>
2806 <tr>
2807 <td>In0</td>
2808 <td>In1</td>
2809 <td>Out</td>
2810 </tr>
2811 <tr>
2812 <td>0</td>
2813 <td>0</td>
2814 <td>0</td>
2815 </tr>
2816 <tr>
2817 <td>0</td>
2818 <td>1</td>
2819 <td>1</td>
2820 </tr>
2821 <tr>
2822 <td>1</td>
2823 <td>0</td>
2824 <td>1</td>
2825 </tr>
2826 <tr>
2827 <td>1</td>
2828 <td>1</td>
2829 <td>0</td>
2830 </tr>
2831 </tbody>
2832</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2833</div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2834<p> </p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2835<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2836<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2837 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2838 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2839 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2840</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2841</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2842
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2843<!-- ======================================================================= -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2844<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2845 <a name="vectorops">Vector Operations</a>
2846</div>
2847
2848<div class="doc_text">
2849
2850<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2851target-independent manner. These instructions cover the element-access and
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2852vector-specific operations needed to process vectors effectively. While LLVM
2853does directly support these vector operations, many sophisticated algorithms
2854will want to use target-specific intrinsics to take full advantage of a specific
2855target.</p>
2856
2857</div>
2858
2859<!-- _______________________________________________________________________ -->
2860<div class="doc_subsubsection">
2861 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
2862</div>
2863
2864<div class="doc_text">
2865
2866<h5>Syntax:</h5>
2867
2868<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2869 &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]2870</pre>
2871
2872<h5>Overview:</h5>
2873
2874<p>
2875The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2876element from a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2877</p>
2878
2879
2880<h5>Arguments:</h5>
2881
2882<p>
2883The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2884value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2885an index indicating the position from which to extract the element.
2886The index may be a variable.</p>
2887
2888<h5>Semantics:</h5>
2889
2890<p>
2891The result is a scalar of the same type as the element type of
2892<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
2893<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
2894results are undefined.
2895</p>
2896
2897<h5>Example:</h5>
2898
2899<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2900 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2901</pre>
2902</div>
2903
2904
2905<!-- _______________________________________________________________________ -->
2906<div class="doc_subsubsection">
2907 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
2908</div>
2909
2910<div class="doc_text">
2911
2912<h5>Syntax:</h5>
2913
2914<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]2915 &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]2916</pre>
2917
2918<h5>Overview:</h5>
2919
2920<p>
2921The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2922element into a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2923</p>
2924
2925
2926<h5>Arguments:</h5>
2927
2928<p>
2929The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2930value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2931scalar value whose type must equal the element type of the first
2932operand. The third operand is an index indicating the position at
2933which to insert the value. The index may be a variable.</p>
2934
2935<h5>Semantics:</h5>
2936
2937<p>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2938The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2939element values are those of <tt>val</tt> except at position
2940<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
2941exceeds the length of <tt>val</tt>, the results are undefined.
2942</p>
2943
2944<h5>Example:</h5>
2945
2946<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2947 %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]2948</pre>
2949</div>
2950
2951<!-- _______________________________________________________________________ -->
2952<div class="doc_subsubsection">
2953 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
2954</div>
2955
2956<div class="doc_text">
2957
2958<h5>Syntax:</h5>
2959
2960<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]2961 &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]2962</pre>
2963
2964<h5>Overview:</h5>
2965
2966<p>
2967The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]2968from two input vectors, returning a vector with the same element type as
2969the input and length that is the same as the shuffle mask.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2970</p>
2971
2972<h5>Arguments:</h5>
2973
2974<p>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]2975The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
2976with types that match each other. The third argument is a shuffle mask whose
2977element type is always 'i32'. The result of the instruction is a vector whose
2978length is the same as the shuffle mask and whose element type is the same as
2979the element type of the first two operands.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2980</p>
2981
2982<p>
2983The shuffle mask operand is required to be a constant vector with either
2984constant integer or undef values.
2985</p>
2986
2987<h5>Semantics:</h5>
2988
2989<p>
2990The elements of the two input vectors are numbered from left to right across
2991both of the vectors. The shuffle mask operand specifies, for each element of
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]2992the result vector, which element of the two input vectors the result element
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2993gets. The element selector may be undef (meaning "don't care") and the second
2994operand may be undef if performing a shuffle from only one vector.
2995</p>
2996
2997<h5>Example:</h5>
2998
2999<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3000 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3001 &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]3002 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
3003 &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]3004 %result = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
3005 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
3006 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
3007 &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]3008</pre>
3009</div>
3010
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]3011
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3012<!-- ======================================================================= -->
3013<div class="doc_subsection">
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3014 <a name="aggregateops">Aggregate Operations</a>
3015</div>
3016
3017<div class="doc_text">
3018
3019<p>LLVM supports several instructions for working with aggregate values.
3020</p>
3021
3022</div>
3023
3024<!-- _______________________________________________________________________ -->
3025<div class="doc_subsubsection">
3026 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3027</div>
3028
3029<div class="doc_text">
3030
3031<h5>Syntax:</h5>
3032
3033<pre>
3034 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3035</pre>
3036
3037<h5>Overview:</h5>
3038
3039<p>
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3040The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3041or array element from an aggregate value.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3042</p>
3043
3044
3045<h5>Arguments:</h5>
3046
3047<p>
3048The first operand of an '<tt>extractvalue</tt>' instruction is a
3049value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3050type. The operands are constant indices to specify which value to extract
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3051in a similar manner as indices in a
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3052'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3053</p>
3054
3055<h5>Semantics:</h5>
3056
3057<p>
3058The result is the value at the position in the aggregate specified by
3059the index operands.
3060</p>
3061
3062<h5>Example:</h5>
3063
3064<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3065 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3066</pre>
3067</div>
3068
3069
3070<!-- _______________________________________________________________________ -->
3071<div class="doc_subsubsection">
3072 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3073</div>
3074
3075<div class="doc_text">
3076
3077<h5>Syntax:</h5>
3078
3079<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3080 &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]3081</pre>
3082
3083<h5>Overview:</h5>
3084
3085<p>
3086The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3087into a struct field or array element in an aggregate.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3088</p>
3089
3090
3091<h5>Arguments:</h5>
3092
3093<p>
3094The first operand of an '<tt>insertvalue</tt>' instruction is a
3095value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
3096The second operand is a first-class value to insert.
Dan Gohmanc4b49eb2008-05-23 21:53:15 +0000[diff] [blame]3097The following operands are constant indices
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3098indicating the position at which to insert the value in a similar manner as
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3099indices in a
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3100'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3101The value to insert must have the same type as the value identified
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3102by the indices.
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3103</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3104
3105<h5>Semantics:</h5>
3106
3107<p>
3108The result is an aggregate of the same type as <tt>val</tt>. Its
3109value is that of <tt>val</tt> except that the value at the position
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3110specified by the indices is that of <tt>elt</tt>.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3111</p>
3112
3113<h5>Example:</h5>
3114
3115<pre>
Dan Gohman52bb2db2008-06-23 15:26:37 +0000[diff] [blame]3116 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3117</pre>
3118</div>
3119
3120
3121<!-- ======================================================================= -->
3122<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3123 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]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 Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3128<p>A key design point of an SSA-based representation is how it
3129represents memory. In LLVM, no memory locations are in SSA form, which
3130makes things very simple. This section describes how to read, write,
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3131allocate, and free memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3132
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3133</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3134
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3135<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3136<div class="doc_subsubsection">
3137 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3138</div>
3139
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3140<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3141
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3142<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3143
3144<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3145 &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]3146</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3147
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3148<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3149
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3150<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]3151heap and returns a pointer to it. The object is always allocated in the generic
3152address space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3153
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3154<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3155
3156<p>The '<tt>malloc</tt>' instruction allocates
3157<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswell6e4ca612004-02-24 16:13:56 +0000[diff] [blame]3158bytes of memory from the operating system and returns a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3159appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3160number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3161If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3162be aligned to at least that boundary. If not specified, or if zero, the target can
3163choose to align the allocation on any convenient boundary.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3164
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3165<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3166
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3167<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3168
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3169<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewycky02ff3082008-11-24 03:41:24 +0000[diff] [blame]3170a pointer is returned. The result of a zero byte allocation is undefined. The
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3171result is null if there is insufficient memory available.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3172
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3173<h5>Example:</h5>
3174
3175<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3176 %array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3177
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3178 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3179 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3180 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3181 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3182 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3183</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3184</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3185
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3186<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3187<div class="doc_subsubsection">
3188 <a name="i_free">'<tt>free</tt>' Instruction</a>
3189</div>
3190
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3191<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3192
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3193<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3194
3195<pre>
3196 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3197</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3198
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3199<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3200
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3201<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]3202memory heap to be reallocated in the future.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3203
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3204<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3205
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3206<p>'<tt>value</tt>' shall be a pointer value that points to a value
3207that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
3208instruction.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3209
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3210<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3211
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3212<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattnere0db56d2008-04-19 22:41:32 +0000[diff] [blame]3213after this instruction executes. If the pointer is null, the operation
3214is a noop.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3215
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3216<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3217
3218<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3219 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
3220 free [4 x i8]* %array
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3221</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3222</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3223
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3224<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3225<div class="doc_subsubsection">
3226 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3227</div>
3228
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3229<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3230
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3231<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3232
3233<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3234 &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]3235</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3236
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3237<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3238
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3239<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
3240currently executing function, to be automatically released when this function
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]3241returns to its caller. The object is always allocated in the generic address
3242space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3243
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3244<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3245
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3246<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3247bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3248appropriate type to the program. If "NumElements" is specified, it is the
3249number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3250If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3251to be aligned to at least that boundary. If not specified, or if zero, the target
3252can choose to align the allocation on any convenient boundary.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3253
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3254<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3255
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3256<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3257
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3258<p>Memory is allocated; a pointer is returned. The operation is undefiend if
3259there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3260memory is automatically released when the function returns. The '<tt>alloca</tt>'
3261instruction is commonly used to represent automatic variables that must
3262have an address available. When the function returns (either with the <tt><a
John Criswelldae2e932005-05-12 16:55:34 +0000[diff] [blame]3263 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]3264instructions), the memory is reclaimed. Allocating zero bytes
3265is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3266
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3267<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3268
3269<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3270 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3271 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3272 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3273 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3274</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3275</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3276
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3277<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3278<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3279Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3280<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3281<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]3282<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]3283<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3284<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3285<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3286<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]3287address from which to load. The pointer must point to a <a
Chris Lattnere53e5082004-06-03 22:57:15 +0000[diff] [blame]3288 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]3289marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3290the number or order of execution of this <tt>load</tt> with other
3291volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3292instructions. </p>
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3293<p>
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3294The optional constant "align" argument specifies the alignment of the operation
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3295(that is, the alignment of the memory address). A value of 0 or an
3296omitted "align" argument means that the operation has the preferential
3297alignment for the target. It is the responsibility of the code emitter
3298to ensure that the alignment information is correct. Overestimating
3299the alignment results in an undefined behavior. Underestimating the
3300alignment may produce less efficient code. An alignment of 1 is always
3301safe.
3302</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3303<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3304<p>The location of memory pointed to is loaded.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3305<h5>Examples:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3306<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3307 <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3308 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
3309 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3310</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3311</div>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3312<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3313<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3314Instruction</a> </div>
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]3315<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3316<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]3317<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
3318 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]3319</pre>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3320<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3321<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3322<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3323<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3324to 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]3325operand must be a pointer to the <a href="#t_firstclass">first class</a> type
3326of the '<tt>&lt;value&gt;</tt>'
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]3327operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3328optimizer is not allowed to modify the number or order of execution of
3329this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
3330 href="#i_store">store</a></tt> instructions.</p>
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3331<p>
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3332The optional constant "align" argument specifies the alignment of the operation
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3333(that is, the alignment of the memory address). A value of 0 or an
3334omitted "align" argument means that the operation has the preferential
3335alignment for the target. It is the responsibility of the code emitter
3336to ensure that the alignment information is correct. Overestimating
3337the alignment results in an undefined behavior. Underestimating the
3338alignment may produce less efficient code. An alignment of 1 is always
3339safe.
3340</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3341<h5>Semantics:</h5>
3342<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
3343at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3344<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3345<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]3346 store i32 3, i32* %ptr <i>; yields {void}</i>
3347 %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]3348</pre>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3349</div>
3350
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3351<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3352<div class="doc_subsubsection">
3353 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3354</div>
3355
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3356<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3357<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3358<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3359 &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]3360</pre>
3361
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3362<h5>Overview:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3363
3364<p>
3365The '<tt>getelementptr</tt>' instruction is used to get the address of a
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3366subelement of an aggregate data structure. It performs address calculation only
3367and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3368
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3369<h5>Arguments:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3370
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3371<p>The first argument is always a pointer, and forms the basis of the
3372calculation. The remaining arguments are indices, that indicate which of the
3373elements of the aggregate object are indexed. The interpretation of each index
3374is dependent on the type being indexed into. The first index always indexes the
3375pointer value given as the first argument, the second index indexes a value of
3376the type pointed to (not necessarily the value directly pointed to, since the
3377first index can be non-zero), etc. The first type indexed into must be a pointer
3378value, subsequent types can be arrays, vectors and structs. Note that subsequent
3379types being indexed into can never be pointers, since that would require loading
3380the pointer before continuing calculation.</p>
3381
3382<p>The type of each index argument depends on the type it is indexing into.
3383When indexing into a (packed) structure, only <tt>i32</tt> integer
3384<b>constants</b> are allowed. When indexing into an array, pointer or vector,
3385only integers of 32 or 64 bits are allowed (also non-constants). 32-bit values
3386will be sign extended to 64-bits if required.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3387
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3388<p>For example, let's consider a C code fragment and how it gets
3389compiled to LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3390
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3391<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3392<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3393struct RT {
3394 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3395 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3396 char C;
3397};
3398struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3399 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3400 double Y;
3401 struct RT Z;
3402};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3403
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3404int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3405 return &amp;s[1].Z.B[5][13];
3406}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3407</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3408</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3409
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3410<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3411
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3412<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3413<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3414%RT = type { i8 , [10 x [20 x i32]], i8 }
3415%ST = type { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3416
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3417define i32* %foo(%ST* %s) {
3418entry:
3419 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3420 ret i32* %reg
3421}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3422</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3423</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3424
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3425<h5>Semantics:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3426
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3427<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]3428type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3429}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3430the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3431i8 }</tt>' type, another structure. The third index indexes into the second
3432element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3433array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3434'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
3435to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3436
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3437<p>Note that it is perfectly legal to index partially through a
3438structure, returning a pointer to an inner element. Because of this,
3439the LLVM code for the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3440
3441<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3442 define i32* %foo(%ST* %s) {
3443 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3444 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3445 %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]3446 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3447 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
3448 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3449 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3450</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3451
3452<p>Note that it is undefined to access an array out of bounds: array and
3453pointer indexes must always be within the defined bounds of the array type.
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]3454The one exception for this rule is zero length arrays. These arrays are
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3455defined to be accessible as variable length arrays, which requires access
3456beyond the zero'th element.</p>
3457
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3458<p>The getelementptr instruction is often confusing. For some more insight
3459into how it works, see <a href="GetElementPtr.html">the getelementptr
3460FAQ</a>.</p>
3461
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3462<h5>Example:</h5>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3463
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3464<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3465 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3466 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
3467 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3468 %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]3469 <i>; yields i8*:eptr</i>
3470 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3471</pre>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3472</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3473
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3474<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3475<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3476</div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3477<div class="doc_text">
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3478<p>The instructions in this category are the conversion instructions (casting)
3479which all take a single operand and a type. They perform various bit conversions
3480on the operand.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3481</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3482
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3483<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3484<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3485 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
3486</div>
3487<div class="doc_text">
3488
3489<h5>Syntax:</h5>
3490<pre>
3491 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3492</pre>
3493
3494<h5>Overview:</h5>
3495<p>
3496The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
3497</p>
3498
3499<h5>Arguments:</h5>
3500<p>
3501The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
3502be 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]3503and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3504type. The bit size of <tt>value</tt> must be larger than the bit size of
3505<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3506
3507<h5>Semantics:</h5>
3508<p>
3509The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3510and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
3511larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
3512It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3513
3514<h5>Example:</h5>
3515<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3516 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3517 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
3518 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3519</pre>
3520</div>
3521
3522<!-- _______________________________________________________________________ -->
3523<div class="doc_subsubsection">
3524 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
3525</div>
3526<div class="doc_text">
3527
3528<h5>Syntax:</h5>
3529<pre>
3530 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3531</pre>
3532
3533<h5>Overview:</h5>
3534<p>The '<tt>zext</tt>' instruction zero extends its operand to type
3535<tt>ty2</tt>.</p>
3536
3537
3538<h5>Arguments:</h5>
3539<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]3540<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3541also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3542<tt>value</tt> must be smaller than the bit size of the destination type,
3543<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3544
3545<h5>Semantics:</h5>
3546<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]3547bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3548
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]3549<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]3550
3551<h5>Example:</h5>
3552<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3553 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3554 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3555</pre>
3556</div>
3557
3558<!-- _______________________________________________________________________ -->
3559<div class="doc_subsubsection">
3560 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3561</div>
3562<div class="doc_text">
3563
3564<h5>Syntax:</h5>
3565<pre>
3566 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3567</pre>
3568
3569<h5>Overview:</h5>
3570<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3571
3572<h5>Arguments:</h5>
3573<p>
3574The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3575<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3576also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3577<tt>value</tt> must be smaller than the bit size of the destination type,
3578<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3579
3580<h5>Semantics:</h5>
3581<p>
3582The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3583bit (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]3584the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3585
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3586<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]3587
3588<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3589<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3590 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3591 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3592</pre>
3593</div>
3594
3595<!-- _______________________________________________________________________ -->
3596<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3597 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3598</div>
3599
3600<div class="doc_text">
3601
3602<h5>Syntax:</h5>
3603
3604<pre>
3605 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3606</pre>
3607
3608<h5>Overview:</h5>
3609<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3610<tt>ty2</tt>.</p>
3611
3612
3613<h5>Arguments:</h5>
3614<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3615 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3616cast it to. The size of <tt>value</tt> must be larger than the size of
3617<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3618<i>no-op cast</i>.</p>
3619
3620<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3621<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3622<a href="#t_floating">floating point</a> type to a smaller
3623<a href="#t_floating">floating point</a> type. If the value cannot fit within
3624the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3625
3626<h5>Example:</h5>
3627<pre>
3628 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3629 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3630</pre>
3631</div>
3632
3633<!-- _______________________________________________________________________ -->
3634<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3635 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3636</div>
3637<div class="doc_text">
3638
3639<h5>Syntax:</h5>
3640<pre>
3641 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3642</pre>
3643
3644<h5>Overview:</h5>
3645<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3646floating point value.</p>
3647
3648<h5>Arguments:</h5>
3649<p>The '<tt>fpext</tt>' instruction takes a
3650<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3651and a <a href="#t_floating">floating point</a> type to cast it to. The source
3652type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3653
3654<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3655<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3656<a href="#t_floating">floating point</a> type to a larger
3657<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3658used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3659<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]3660
3661<h5>Example:</h5>
3662<pre>
3663 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3664 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3665</pre>
3666</div>
3667
3668<!-- _______________________________________________________________________ -->
3669<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]3670 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3671</div>
3672<div class="doc_text">
3673
3674<h5>Syntax:</h5>
3675<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3676 &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]3677</pre>
3678
3679<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3680<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3681unsigned integer equivalent of type <tt>ty2</tt>.
3682</p>
3683
3684<h5>Arguments:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3685<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]3686scalar or vector <a href="#t_floating">floating point</a> value, and a type
3687to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3688type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3689vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3690
3691<h5>Semantics:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3692<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3693<a href="#t_floating">floating point</a> operand into the nearest (rounding
3694towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3695the results are undefined.</p>
3696
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3697<h5>Example:</h5>
3698<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3699 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3700 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3701 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3702</pre>
3703</div>
3704
3705<!-- _______________________________________________________________________ -->
3706<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3707 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3708</div>
3709<div class="doc_text">
3710
3711<h5>Syntax:</h5>
3712<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3713 &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]3714</pre>
3715
3716<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3717<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3718<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]3719</p>
3720
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3721<h5>Arguments:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3722<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]3723scalar or vector <a href="#t_floating">floating point</a> value, and a type
3724to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3725type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3726vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3727
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3728<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3729<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3730<a href="#t_floating">floating point</a> operand into the nearest (rounding
3731towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3732the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3733
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3734<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3735<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3736 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3737 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3738 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3739</pre>
3740</div>
3741
3742<!-- _______________________________________________________________________ -->
3743<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3744 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3745</div>
3746<div class="doc_text">
3747
3748<h5>Syntax:</h5>
3749<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3750 &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]3751</pre>
3752
3753<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3754<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3755integer and converts that value to the <tt>ty2</tt> type.</p>
3756
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3757<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3758<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3759scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3760to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3761type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3762floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3763
3764<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3765<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3766integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3767the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3768
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3769<h5>Example:</h5>
3770<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3771 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3772 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3773</pre>
3774</div>
3775
3776<!-- _______________________________________________________________________ -->
3777<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3778 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3779</div>
3780<div class="doc_text">
3781
3782<h5>Syntax:</h5>
3783<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3784 &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]3785</pre>
3786
3787<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3788<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3789integer and converts that value to the <tt>ty2</tt> type.</p>
3790
3791<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3792<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3793scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3794to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3795type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3796floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3797
3798<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3799<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3800integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3801the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3802
3803<h5>Example:</h5>
3804<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3805 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3806 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3807</pre>
3808</div>
3809
3810<!-- _______________________________________________________________________ -->
3811<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3812 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3813</div>
3814<div class="doc_text">
3815
3816<h5>Syntax:</h5>
3817<pre>
3818 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3819</pre>
3820
3821<h5>Overview:</h5>
3822<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3823the integer type <tt>ty2</tt>.</p>
3824
3825<h5>Arguments:</h5>
3826<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3827must 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]3828<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]3829
3830<h5>Semantics:</h5>
3831<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3832<tt>ty2</tt> by interpreting the pointer value as an integer and either
3833truncating or zero extending that value to the size of the integer type. If
3834<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3835<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]3836are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3837change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3838
3839<h5>Example:</h5>
3840<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3841 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3842 %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]3843</pre>
3844</div>
3845
3846<!-- _______________________________________________________________________ -->
3847<div class="doc_subsubsection">
3848 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3849</div>
3850<div class="doc_text">
3851
3852<h5>Syntax:</h5>
3853<pre>
3854 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3855</pre>
3856
3857<h5>Overview:</h5>
3858<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
3859a pointer type, <tt>ty2</tt>.</p>
3860
3861<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3862<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3863value to cast, and a type to cast it to, which must be a
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3864<a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3865
3866<h5>Semantics:</h5>
3867<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
3868<tt>ty2</tt> by applying either a zero extension or a truncation depending on
3869the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
3870size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
3871the size of a pointer then a zero extension is done. If they are the same size,
3872nothing is done (<i>no-op cast</i>).</p>
3873
3874<h5>Example:</h5>
3875<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3876 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
3877 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
3878 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3879</pre>
3880</div>
3881
3882<!-- _______________________________________________________________________ -->
3883<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3884 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3885</div>
3886<div class="doc_text">
3887
3888<h5>Syntax:</h5>
3889<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3890 &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]3891</pre>
3892
3893<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3894
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3895<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3896<tt>ty2</tt> without changing any bits.</p>
3897
3898<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3899
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3900<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Dan Gohman500233a2008-09-08 16:45:59 +0000[diff] [blame]3901a non-aggregate first class value, and a type to cast it to, which must also be
3902a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
3903<tt>value</tt>
Reid Spencer19b569f2007-01-09 20:08:58 +0000[diff] [blame]3904and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3905type is a pointer, the destination type must also be a pointer. This
3906instruction supports bitwise conversion of vectors to integers and to vectors
3907of other types (as long as they have the same size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3908
3909<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3910<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3911<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
3912this conversion. The conversion is done as if the <tt>value</tt> had been
3913stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
3914converted to other pointer types with this instruction. To convert pointers to
3915other types, use the <a href="#i_inttoptr">inttoptr</a> or
3916<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3917
3918<h5>Example:</h5>
3919<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3920 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3921 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3922 %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]3923</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3924</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3925
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3926<!-- ======================================================================= -->
3927<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
3928<div class="doc_text">
3929<p>The instructions in this category are the "miscellaneous"
3930instructions, which defy better classification.</p>
3931</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3932
3933<!-- _______________________________________________________________________ -->
3934<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
3935</div>
3936<div class="doc_text">
3937<h5>Syntax:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3938<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]3939</pre>
3940<h5>Overview:</h5>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]3941<p>The '<tt>icmp</tt>' instruction returns a boolean value or
3942a vector of boolean values based on comparison
3943of its two integer, integer vector, or pointer operands.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3944<h5>Arguments:</h5>
3945<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3946the condition code indicating the kind of comparison to perform. It is not
3947a value, just a keyword. The possible condition code are:
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3948</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3949<ol>
3950 <li><tt>eq</tt>: equal</li>
3951 <li><tt>ne</tt>: not equal </li>
3952 <li><tt>ugt</tt>: unsigned greater than</li>
3953 <li><tt>uge</tt>: unsigned greater or equal</li>
3954 <li><tt>ult</tt>: unsigned less than</li>
3955 <li><tt>ule</tt>: unsigned less or equal</li>
3956 <li><tt>sgt</tt>: signed greater than</li>
3957 <li><tt>sge</tt>: signed greater or equal</li>
3958 <li><tt>slt</tt>: signed less than</li>
3959 <li><tt>sle</tt>: signed less or equal</li>
3960</ol>
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3961<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]3962<a href="#t_pointer">pointer</a>
3963or integer <a href="#t_vector">vector</a> typed.
3964They must also be identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3965<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3966<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]3967the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]3968yields 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]3969</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3970<ol>
3971 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
3972 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3973 </li>
3974 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3975 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3976 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3977 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3978 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3979 <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]3980 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3981 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3982 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3983 <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]3984 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3985 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3986 <li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3987 <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]3988 <li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3989 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3990 <li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3991 <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]3992</ol>
3993<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3994values are compared as if they were integers.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]3995<p>If the operands are integer vectors, then they are compared
3996element by element. The result is an <tt>i1</tt> vector with
3997the same number of elements as the values being compared.
3998Otherwise, the result is an <tt>i1</tt>.
3999</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4000
4001<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4002<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
4003 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4004 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4005 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4006 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4007 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4008</pre>
4009</div>
4010
4011<!-- _______________________________________________________________________ -->
4012<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4013</div>
4014<div class="doc_text">
4015<h5>Syntax:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4016<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]4017</pre>
4018<h5>Overview:</h5>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4019<p>The '<tt>fcmp</tt>' instruction returns a boolean value
4020or vector of boolean values based on comparison
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4021of its operands.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4022<p>
4023If the operands are floating point scalars, then the result
4024type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
4025</p>
4026<p>If the operands are floating point vectors, then the result type
4027is a vector of boolean with the same number of elements as the
4028operands being compared.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4029<h5>Arguments:</h5>
4030<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4031the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4032a value, just a keyword. The possible condition code are:</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4033<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4034 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4035 <li><tt>oeq</tt>: ordered and equal</li>
4036 <li><tt>ogt</tt>: ordered and greater than </li>
4037 <li><tt>oge</tt>: ordered and greater than or equal</li>
4038 <li><tt>olt</tt>: ordered and less than </li>
4039 <li><tt>ole</tt>: ordered and less than or equal</li>
4040 <li><tt>one</tt>: ordered and not equal</li>
4041 <li><tt>ord</tt>: ordered (no nans)</li>
4042 <li><tt>ueq</tt>: unordered or equal</li>
4043 <li><tt>ugt</tt>: unordered or greater than </li>
4044 <li><tt>uge</tt>: unordered or greater than or equal</li>
4045 <li><tt>ult</tt>: unordered or less than </li>
4046 <li><tt>ule</tt>: unordered or less than or equal</li>
4047 <li><tt>une</tt>: unordered or not equal</li>
4048 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4049 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4050</ol>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4051<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer93a49852006-12-06 07:08:07 +0000[diff] [blame]4052<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4053<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
4054either a <a href="#t_floating">floating point</a> type
4055or a <a href="#t_vector">vector</a> of floating point type.
4056They must have identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4057<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4058<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4059according to the condition code given as <tt>cond</tt>.
4060If the operands are vectors, then the vectors are compared
4061element by element.
4062Each comparison performed
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4063always yields an <a href="#t_primitive">i1</a> result, as follows:</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4064<ol>
4065 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4066 <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]4067 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4068 <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]4069 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4070 <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]4071 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4072 <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]4073 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4074 <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]4075 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4076 <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]4077 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4078 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
4079 <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]4080 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4081 <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]4082 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4083 <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]4084 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4085 <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]4086 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4087 <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]4088 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4089 <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]4090 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4091 <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]4092 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4093</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4094
4095<h5>Example:</h5>
4096<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]4097 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4098 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4099 &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]4100</pre>
4101</div>
4102
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4103<!-- _______________________________________________________________________ -->
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4104<div class="doc_subsubsection">
4105 <a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
4106</div>
4107<div class="doc_text">
4108<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4109<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]4110</pre>
4111<h5>Overview:</h5>
4112<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
4113element-wise comparison of its two integer vector operands.</p>
4114<h5>Arguments:</h5>
4115<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
4116the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4117a value, just a keyword. The possible condition code are:</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4118<ol>
4119 <li><tt>eq</tt>: equal</li>
4120 <li><tt>ne</tt>: not equal </li>
4121 <li><tt>ugt</tt>: unsigned greater than</li>
4122 <li><tt>uge</tt>: unsigned greater or equal</li>
4123 <li><tt>ult</tt>: unsigned less than</li>
4124 <li><tt>ule</tt>: unsigned less or equal</li>
4125 <li><tt>sgt</tt>: signed greater than</li>
4126 <li><tt>sge</tt>: signed greater or equal</li>
4127 <li><tt>slt</tt>: signed less than</li>
4128 <li><tt>sle</tt>: signed less or equal</li>
4129</ol>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4130<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4131<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
4132<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4133<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4134according to the condition code given as <tt>cond</tt>. The comparison yields a
4135<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
4136identical type as the values being compared. The most significant bit in each
4137element is 1 if the element-wise comparison evaluates to true, and is 0
4138otherwise. All other bits of the result are undefined. The condition codes
4139are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4140instruction</a>.</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4141
4142<h5>Example:</h5>
4143<pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4144 &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>
4145 &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]4146</pre>
4147</div>
4148
4149<!-- _______________________________________________________________________ -->
4150<div class="doc_subsubsection">
4151 <a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
4152</div>
4153<div class="doc_text">
4154<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4155<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]4156<h5>Overview:</h5>
4157<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
4158element-wise comparison of its two floating point vector operands. The output
4159elements have the same width as the input elements.</p>
4160<h5>Arguments:</h5>
4161<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
4162the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4163a value, just a keyword. The possible condition code are:</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4164<ol>
4165 <li><tt>false</tt>: no comparison, always returns false</li>
4166 <li><tt>oeq</tt>: ordered and equal</li>
4167 <li><tt>ogt</tt>: ordered and greater than </li>
4168 <li><tt>oge</tt>: ordered and greater than or equal</li>
4169 <li><tt>olt</tt>: ordered and less than </li>
4170 <li><tt>ole</tt>: ordered and less than or equal</li>
4171 <li><tt>one</tt>: ordered and not equal</li>
4172 <li><tt>ord</tt>: ordered (no nans)</li>
4173 <li><tt>ueq</tt>: unordered or equal</li>
4174 <li><tt>ugt</tt>: unordered or greater than </li>
4175 <li><tt>uge</tt>: unordered or greater than or equal</li>
4176 <li><tt>ult</tt>: unordered or less than </li>
4177 <li><tt>ule</tt>: unordered or less than or equal</li>
4178 <li><tt>une</tt>: unordered or not equal</li>
4179 <li><tt>uno</tt>: unordered (either nans)</li>
4180 <li><tt>true</tt>: no comparison, always returns true</li>
4181</ol>
4182<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
4183<a href="#t_floating">floating point</a> typed. They must also be identical
4184types.</p>
4185<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4186<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4187according to the condition code given as <tt>cond</tt>. The comparison yields a
4188<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
4189an identical number of elements as the values being compared, and each element
4190having identical with to the width of the floating point elements. The most
4191significant bit in each element is 1 if the element-wise comparison evaluates to
4192true, and is 0 otherwise. All other bits of the result are undefined. The
4193condition codes are evaluated identically to the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4194<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4195
4196<h5>Example:</h5>
4197<pre>
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]4198 <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0, i32 -1 &gt;</i>
4199 &lt;result&gt; = vfcmp oeq &lt;2 x float&gt; &lt; float 4, float 0 &gt;, &lt; float 5, float 0 &gt;
4200
4201 <i>; yields: result=&lt;2 x i64&gt; &lt; i64 -1, i64 0 &gt;</i>
4202 &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]4203</pre>
4204</div>
4205
4206<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4207<div class="doc_subsubsection">
4208 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4209</div>
4210
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4211<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4212
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4213<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4214
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4215<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
4216<h5>Overview:</h5>
4217<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
4218the SSA graph representing the function.</p>
4219<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4220
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4221<p>The type of the incoming values is specified with the first type
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4222field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
4223as arguments, with one pair for each predecessor basic block of the
4224current block. Only values of <a href="#t_firstclass">first class</a>
4225type may be used as the value arguments to the PHI node. Only labels
4226may be used as the label arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4227
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4228<p>There must be no non-phi instructions between the start of a basic
4229block and the PHI instructions: i.e. PHI instructions must be first in
4230a basic block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4231
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4232<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4233
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4234<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
4235specified by the pair corresponding to the predecessor basic block that executed
4236just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4237
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4238<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4239<pre>
4240Loop: ; Infinite loop that counts from 0 on up...
4241 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4242 %nextindvar = add i32 %indvar, 1
4243 br label %Loop
4244</pre>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4245</div>
4246
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4247<!-- _______________________________________________________________________ -->
4248<div class="doc_subsubsection">
4249 <a name="i_select">'<tt>select</tt>' Instruction</a>
4250</div>
4251
4252<div class="doc_text">
4253
4254<h5>Syntax:</h5>
4255
4256<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4257 &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>
4258
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4259 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4260</pre>
4261
4262<h5>Overview:</h5>
4263
4264<p>
4265The '<tt>select</tt>' instruction is used to choose one value based on a
4266condition, without branching.
4267</p>
4268
4269
4270<h5>Arguments:</h5>
4271
4272<p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4273The '<tt>select</tt>' instruction requires an 'i1' value or
4274a vector of 'i1' values indicating the
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4275condition, and two values of the same <a href="#t_firstclass">first class</a>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4276type. If the val1/val2 are vectors and
4277the condition is a scalar, then entire vectors are selected, not
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4278individual elements.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4279</p>
4280
4281<h5>Semantics:</h5>
4282
4283<p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4284If 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]4285value argument; otherwise, it returns the second value argument.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4286</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4287<p>
4288If the condition is a vector of i1, then the value arguments must
4289be vectors of the same size, and the selection is done element
4290by element.
4291</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4292
4293<h5>Example:</h5>
4294
4295<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4296 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4297</pre>
4298</div>
4299
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]4300
4301<!-- _______________________________________________________________________ -->
4302<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4303 <a name="i_call">'<tt>call</tt>' Instruction</a>
4304</div>
4305
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4306<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4307
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4308<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4309<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]4310 &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]4311</pre>
4312
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4313<h5>Overview:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4314
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4315<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4316
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4317<h5>Arguments:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4318
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4319<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4320
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4321<ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4322 <li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4323 <p>The optional "tail" marker indicates whether the callee function accesses
4324 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4325 function call is eligible for tail call optimization. Note that calls may
4326 be marked "tail" even if they do not occur before a <a
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4327 href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4328 </li>
4329 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4330 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4331 convention</a> the call should use. If none is specified, the call defaults
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4332 to using C calling conventions.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4333 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4334
4335 <li>
4336 <p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4337 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
4338 and '<tt>inreg</tt>' attributes are valid here.</p>
4339 </li>
4340
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4341 <li>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4342 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
4343 the type of the return value. Functions that return no value are marked
4344 <tt><a href="#t_void">void</a></tt>.</p>
4345 </li>
4346 <li>
4347 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
4348 value being invoked. The argument types must match the types implied by
4349 this signature. This type can be omitted if the function is not varargs
4350 and if the function type does not return a pointer to a function.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4351 </li>
4352 <li>
4353 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4354 be invoked. In most cases, this is a direct function invocation, but
4355 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4356 to function value.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4357 </li>
4358 <li>
4359 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencera7e302a2005-05-01 22:22:57 +0000[diff] [blame]4360 function signature argument types. All arguments must be of
4361 <a href="#t_firstclass">first class</a> type. If the function signature
4362 indicates the function accepts a variable number of arguments, the extra
4363 arguments can be specified.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4364 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4365 <li>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]4366 <p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4367 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
4368 '<tt>readnone</tt>' attributes are valid here.</p>
4369 </li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4370</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4371
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4372<h5>Semantics:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4373
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4374<p>The '<tt>call</tt>' instruction is used to cause control flow to
4375transfer to a specified function, with its incoming arguments bound to
4376the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
4377instruction in the called function, control flow continues with the
4378instruction after the function call, and the return value of the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4379function is bound to the result argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4380
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4381<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4382
4383<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4384 %retval = call i32 @test(i32 %argc)
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]4385 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4386 %X = tail call i32 @foo() <i>; yields i32</i>
4387 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4388 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]4389
4390 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4391 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]4392 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
4393 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]4394 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]4395 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4396</pre>
4397
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4398</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4399
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4400<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4401<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]4402 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4403</div>
4404
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4405<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4406
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4407<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4408
4409<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4410 &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]4411</pre>
4412
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4413<h5>Overview:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4414
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4415<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4416the "variable argument" area of a function call. It is used to implement the
4417<tt>va_arg</tt> macro in C.</p>
4418
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4419<h5>Arguments:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4420
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4421<p>This instruction takes a <tt>va_list*</tt> value and the type of
4422the argument. It returns a value of the specified argument type and
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4423increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4424actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4425
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4426<h5>Semantics:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4427
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4428<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
4429type from the specified <tt>va_list</tt> and causes the
4430<tt>va_list</tt> to point to the next argument. For more information,
4431see the variable argument handling <a href="#int_varargs">Intrinsic
4432Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4433
4434<p>It is legal for this instruction to be called in a function which does not
4435take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4436function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4437
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4438<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4439href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4440argument.</p>
4441
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4442<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4443
4444<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4445
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4446</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4447
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4448<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4449<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4450<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4451
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4452<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4453
4454<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4455well known names and semantics and are required to follow certain restrictions.
4456Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4457language that does not require changing all of the transformations in LLVM when
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]4458adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4459
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4460<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4461prefix is reserved in LLVM for intrinsic names; thus, function names may not
4462begin with this prefix. Intrinsic functions must always be external functions:
4463you cannot define the body of intrinsic functions. Intrinsic functions may
4464only be used in call or invoke instructions: it is illegal to take the address
4465of an intrinsic function. Additionally, because intrinsic functions are part
4466of the LLVM language, it is required if any are added that they be documented
4467here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4468
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4469<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
4470a family of functions that perform the same operation but on different data
4471types. Because LLVM can represent over 8 million different integer types,
4472overloading is used commonly to allow an intrinsic function to operate on any
4473integer type. One or more of the argument types or the result type can be
4474overloaded to accept any integer type. Argument types may also be defined as
4475exactly matching a previous argument's type or the result type. This allows an
4476intrinsic function which accepts multiple arguments, but needs all of them to
4477be of the same type, to only be overloaded with respect to a single argument or
4478the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4479
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4480<p>Overloaded intrinsics will have the names of its overloaded argument types
4481encoded into its function name, each preceded by a period. Only those types
4482which are overloaded result in a name suffix. Arguments whose type is matched
4483against another type do not. For example, the <tt>llvm.ctpop</tt> function can
4484take an integer of any width and returns an integer of exactly the same integer
4485width. This leads to a family of functions such as
4486<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
4487Only one type, the return type, is overloaded, and only one type suffix is
4488required. Because the argument's type is matched against the return type, it
4489does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4490
4491<p>To learn how to add an intrinsic function, please see the
4492<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4493</p>
4494
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4495</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4496
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4497<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4498<div class="doc_subsection">
4499 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
4500</div>
4501
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4502<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4503
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4504<p>Variable argument support is defined in LLVM with the <a
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]4505 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4506intrinsic functions. These functions are related to the similarly
4507named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4508
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4509<p>All of these functions operate on arguments that use a
4510target-specific value type "<tt>va_list</tt>". The LLVM assembly
4511language reference manual does not define what this type is, so all
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4512transformations should be prepared to handle these functions regardless of
4513the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4514
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]4515<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]4516instruction and the variable argument handling intrinsic functions are
4517used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4518
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4519<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4520<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4521define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4522 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4523 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4524 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4525 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4526
4527 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4528 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4529
4530 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4531 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4532 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4533 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4534 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4535
4536 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4537 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4538 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4539}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4540
4541declare void @llvm.va_start(i8*)
4542declare void @llvm.va_copy(i8*, i8*)
4543declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4544</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4545</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4546
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4547</div>
4548
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4549<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4550<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4551 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4552</div>
4553
4554
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4555<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4556<h5>Syntax:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4557<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4558<h5>Overview:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4559<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4560<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
4561href="#i_va_arg">va_arg</a></tt>.</p>
4562
4563<h5>Arguments:</h5>
4564
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4565<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]4566
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4567<h5>Semantics:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4568
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4569<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]4570macro available in C. In a target-dependent way, it initializes the
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4571<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]4572<tt>va_arg</tt> will produce the first variable argument passed to the function.
4573Unlike 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]4574last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4575
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4576</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4577
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4578<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4579<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4580 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4581</div>
4582
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4583<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4584<h5>Syntax:</h5>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4585<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4586<h5>Overview:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4587
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4588<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4589which 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]4590or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4591
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4592<h5>Arguments:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4593
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4594<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]4595
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4596<h5>Semantics:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4597
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4598<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]4599macro available in C. In a target-dependent way, it destroys the
4600<tt>va_list</tt> element to which the argument points. Calls to <a
4601href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
4602<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
4603<tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4604
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4605</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4606
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4607<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4608<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4609 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4610</div>
4611
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4612<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4613
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4614<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4615
4616<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4617 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4618</pre>
4619
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4620<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4621
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4622<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
4623from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4624
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4625<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4626
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4627<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]4628The 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]4629
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4630
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4631<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4632
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4633<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
4634macro available in C. In a target-dependent way, it copies the source
4635<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
4636intrinsic is necessary because the <tt><a href="#int_va_start">
4637llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
4638example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4639
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4640</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4641
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4642<!-- ======================================================================= -->
4643<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4644 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
4645</div>
4646
4647<div class="doc_text">
4648
4649<p>
4650LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]4651Collection</a> (GC) requires the implementation and generation of these
4652intrinsics.
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4653These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4654stack</a>, as well as garbage collector implementations that require <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4655href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4656Front-ends for type-safe garbage collected languages should generate these
4657intrinsics to make use of the LLVM garbage collectors. For more details, see <a
4658href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
4659</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]4660
4661<p>The garbage collection intrinsics only operate on objects in the generic
4662 address space (address space zero).</p>
4663
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4664</div>
4665
4666<!-- _______________________________________________________________________ -->
4667<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4668 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4669</div>
4670
4671<div class="doc_text">
4672
4673<h5>Syntax:</h5>
4674
4675<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4676 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4677</pre>
4678
4679<h5>Overview:</h5>
4680
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]4681<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]4682the code generator, and allows some metadata to be associated with it.</p>
4683
4684<h5>Arguments:</h5>
4685
4686<p>The first argument specifies the address of a stack object that contains the
4687root pointer. The second pointer (which must be either a constant or a global
4688value address) contains the meta-data to be associated with the root.</p>
4689
4690<h5>Semantics:</h5>
4691
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]4692<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]4693location. At compile-time, the code generator generates information to allow
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4694the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
4695intrinsic may only be used in a function which <a href="#gc">specifies a GC
4696algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4697
4698</div>
4699
4700
4701<!-- _______________________________________________________________________ -->
4702<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4703 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4704</div>
4705
4706<div class="doc_text">
4707
4708<h5>Syntax:</h5>
4709
4710<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4711 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4712</pre>
4713
4714<h5>Overview:</h5>
4715
4716<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4717locations, allowing garbage collector implementations that require read
4718barriers.</p>
4719
4720<h5>Arguments:</h5>
4721
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4722<p>The second argument is the address to read from, which should be an address
4723allocated from the garbage collector. The first object is a pointer to the
4724start of the referenced object, if needed by the language runtime (otherwise
4725null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4726
4727<h5>Semantics:</h5>
4728
4729<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4730instruction, but may be replaced with substantially more complex code by the
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4731garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
4732may only be used in a function which <a href="#gc">specifies a GC
4733algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4734
4735</div>
4736
4737
4738<!-- _______________________________________________________________________ -->
4739<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4740 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4741</div>
4742
4743<div class="doc_text">
4744
4745<h5>Syntax:</h5>
4746
4747<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4748 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4749</pre>
4750
4751<h5>Overview:</h5>
4752
4753<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4754locations, allowing garbage collector implementations that require write
4755barriers (such as generational or reference counting collectors).</p>
4756
4757<h5>Arguments:</h5>
4758
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4759<p>The first argument is the reference to store, the second is the start of the
4760object to store it to, and the third is the address of the field of Obj to
4761store to. If the runtime does not require a pointer to the object, Obj may be
4762null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4763
4764<h5>Semantics:</h5>
4765
4766<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4767instruction, but may be replaced with substantially more complex code by the
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4768garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
4769may only be used in a function which <a href="#gc">specifies a GC
4770algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4771
4772</div>
4773
4774
4775
4776<!-- ======================================================================= -->
4777<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4778 <a name="int_codegen">Code Generator Intrinsics</a>
4779</div>
4780
4781<div class="doc_text">
4782<p>
4783These intrinsics are provided by LLVM to expose special features that may only
4784be implemented with code generator support.
4785</p>
4786
4787</div>
4788
4789<!-- _______________________________________________________________________ -->
4790<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4791 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4792</div>
4793
4794<div class="doc_text">
4795
4796<h5>Syntax:</h5>
4797<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4798 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4799</pre>
4800
4801<h5>Overview:</h5>
4802
4803<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4804The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4805target-specific value indicating the return address of the current function
4806or one of its callers.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4807</p>
4808
4809<h5>Arguments:</h5>
4810
4811<p>
4812The argument to this intrinsic indicates which function to return the address
4813for. Zero indicates the calling function, one indicates its caller, etc. The
4814argument is <b>required</b> to be a constant integer value.
4815</p>
4816
4817<h5>Semantics:</h5>
4818
4819<p>
4820The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4821the return address of the specified call frame, or zero if it cannot be
4822identified. The value returned by this intrinsic is likely to be incorrect or 0
4823for arguments other than zero, so it should only be used for debugging purposes.
4824</p>
4825
4826<p>
4827Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4828aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4829source-language caller.
4830</p>
4831</div>
4832
4833
4834<!-- _______________________________________________________________________ -->
4835<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4836 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4837</div>
4838
4839<div class="doc_text">
4840
4841<h5>Syntax:</h5>
4842<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4843 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4844</pre>
4845
4846<h5>Overview:</h5>
4847
4848<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4849The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
4850target-specific frame pointer value for the specified stack frame.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4851</p>
4852
4853<h5>Arguments:</h5>
4854
4855<p>
4856The argument to this intrinsic indicates which function to return the frame
4857pointer for. Zero indicates the calling function, one indicates its caller,
4858etc. The argument is <b>required</b> to be a constant integer value.
4859</p>
4860
4861<h5>Semantics:</h5>
4862
4863<p>
4864The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
4865the frame address of the specified call frame, or zero if it cannot be
4866identified. The value returned by this intrinsic is likely to be incorrect or 0
4867for arguments other than zero, so it should only be used for debugging purposes.
4868</p>
4869
4870<p>
4871Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4872aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4873source-language caller.
4874</p>
4875</div>
4876
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4877<!-- _______________________________________________________________________ -->
4878<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4879 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4880</div>
4881
4882<div class="doc_text">
4883
4884<h5>Syntax:</h5>
4885<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4886 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4887</pre>
4888
4889<h5>Overview:</h5>
4890
4891<p>
4892The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4893the function stack, for use with <a href="#int_stackrestore">
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4894<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
4895features like scoped automatic variable sized arrays in C99.
4896</p>
4897
4898<h5>Semantics:</h5>
4899
4900<p>
4901This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4902href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4903<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
4904<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
4905state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
4906practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
4907that were allocated after the <tt>llvm.stacksave</tt> was executed.
4908</p>
4909
4910</div>
4911
4912<!-- _______________________________________________________________________ -->
4913<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4914 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4915</div>
4916
4917<div class="doc_text">
4918
4919<h5>Syntax:</h5>
4920<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4921 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4922</pre>
4923
4924<h5>Overview:</h5>
4925
4926<p>
4927The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
4928the function stack to the state it was in when the corresponding <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4929href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4930useful for implementing language features like scoped automatic variable sized
4931arrays in C99.
4932</p>
4933
4934<h5>Semantics:</h5>
4935
4936<p>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4937See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4938</p>
4939
4940</div>
4941
4942
4943<!-- _______________________________________________________________________ -->
4944<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4945 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4946</div>
4947
4948<div class="doc_text">
4949
4950<h5>Syntax:</h5>
4951<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4952 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]4953</pre>
4954
4955<h5>Overview:</h5>
4956
4957
4958<p>
4959The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4960a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
4961no
4962effect on the behavior of the program but can change its performance
Chris Lattner2a615362005-02-28 19:47:14 +0000[diff] [blame]4963characteristics.
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4964</p>
4965
4966<h5>Arguments:</h5>
4967
4968<p>
4969<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
4970determining if the fetch should be for a read (0) or write (1), and
4971<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattneraeffb4a2005-03-07 20:31:38 +0000[diff] [blame]4972locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4973<tt>locality</tt> arguments must be constant integers.
4974</p>
4975
4976<h5>Semantics:</h5>
4977
4978<p>
4979This intrinsic does not modify the behavior of the program. In particular,
4980prefetches cannot trap and do not produce a value. On targets that support this
4981intrinsic, the prefetch can provide hints to the processor cache for better
4982performance.
4983</p>
4984
4985</div>
4986
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4987<!-- _______________________________________________________________________ -->
4988<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4989 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4990</div>
4991
4992<div class="doc_text">
4993
4994<h5>Syntax:</h5>
4995<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4996 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4997</pre>
4998
4999<h5>Overview:</h5>
5000
5001
5002<p>
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5003The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5004(PC) in a region of
5005code to simulators and other tools. The method is target specific, but it is
5006expected that the marker will use exported symbols to transmit the PC of the
5007marker.
5008The marker makes no guarantees that it will remain with any specific instruction
5009after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb3e7afd2006-03-24 07:16:10 +0000[diff] [blame]5010optimizations. The intended use is to be inserted after optimizations to allow
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5011correlations of simulation runs.
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5012</p>
5013
5014<h5>Arguments:</h5>
5015
5016<p>
5017<tt>id</tt> is a numerical id identifying the marker.
5018</p>
5019
5020<h5>Semantics:</h5>
5021
5022<p>
5023This intrinsic does not modify the behavior of the program. Backends that do not
5024support this intrinisic may ignore it.
5025</p>
5026
5027</div>
5028
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5029<!-- _______________________________________________________________________ -->
5030<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5031 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5032</div>
5033
5034<div class="doc_text">
5035
5036<h5>Syntax:</h5>
5037<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5038 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5039</pre>
5040
5041<h5>Overview:</h5>
5042
5043
5044<p>
5045The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5046counter register (or similar low latency, high accuracy clocks) on those targets
5047that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
5048As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
5049should only be used for small timings.
5050</p>
5051
5052<h5>Semantics:</h5>
5053
5054<p>
5055When directly supported, reading the cycle counter should not modify any memory.
5056Implementations are allowed to either return a application specific value or a
5057system wide value. On backends without support, this is lowered to a constant 0.
5058</p>
5059
5060</div>
5061
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5062<!-- ======================================================================= -->
5063<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5064 <a name="int_libc">Standard C Library Intrinsics</a>
5065</div>
5066
5067<div class="doc_text">
5068<p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5069LLVM provides intrinsics for a few important standard C library functions.
5070These intrinsics allow source-language front-ends to pass information about the
5071alignment of the pointer arguments to the code generator, providing opportunity
5072for more efficient code generation.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5073</p>
5074
5075</div>
5076
5077<!-- _______________________________________________________________________ -->
5078<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5079 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5080</div>
5081
5082<div class="doc_text">
5083
5084<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5085<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
5086width. Not all targets support all bit widths however.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5087<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5088 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5089 i8 &lt;len&gt;, i32 &lt;align&gt;)
5090 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5091 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5092 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5093 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5094 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5095 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5096</pre>
5097
5098<h5>Overview:</h5>
5099
5100<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5101The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5102location to the destination location.
5103</p>
5104
5105<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5106Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5107intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5108</p>
5109
5110<h5>Arguments:</h5>
5111
5112<p>
5113The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5114the source. The third argument is an integer argument
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5115specifying the number of bytes to copy, and the fourth argument is the alignment
5116of the source and destination locations.
5117</p>
5118
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5119<p>
5120If 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]5121the caller guarantees that both the source and destination pointers are aligned
5122to that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5123</p>
5124
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5125<h5>Semantics:</h5>
5126
5127<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5128The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5129location to the destination location, which are not allowed to overlap. It
5130copies "len" bytes of memory over. If the argument is known to be aligned to
5131some boundary, this can be specified as the fourth argument, otherwise it should
5132be set to 0 or 1.
5133</p>
5134</div>
5135
5136
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5137<!-- _______________________________________________________________________ -->
5138<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5139 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5140</div>
5141
5142<div class="doc_text">
5143
5144<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5145<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
5146width. Not all targets support all bit widths however.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5147<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5148 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5149 i8 &lt;len&gt;, i32 &lt;align&gt;)
5150 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5151 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5152 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5153 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5154 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5155 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5156</pre>
5157
5158<h5>Overview:</h5>
5159
5160<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5161The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
5162location to the destination location. It is similar to the
Chris Lattner4b2cbcf2008-01-06 19:51:52 +0000[diff] [blame]5163'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5164</p>
5165
5166<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5167Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5168intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5169</p>
5170
5171<h5>Arguments:</h5>
5172
5173<p>
5174The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5175the source. The third argument is an integer argument
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5176specifying the number of bytes to copy, and the fourth argument is the alignment
5177of the source and destination locations.
5178</p>
5179
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5180<p>
5181If 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]5182the caller guarantees that the source and destination pointers are aligned to
5183that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5184</p>
5185
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5186<h5>Semantics:</h5>
5187
5188<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5189The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5190location to the destination location, which may overlap. It
5191copies "len" bytes of memory over. If the argument is known to be aligned to
5192some boundary, this can be specified as the fourth argument, otherwise it should
5193be set to 0 or 1.
5194</p>
5195</div>
5196
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5197
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5198<!-- _______________________________________________________________________ -->
5199<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5200 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5201</div>
5202
5203<div class="doc_text">
5204
5205<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5206<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
5207width. Not all targets support all bit widths however.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5208<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5209 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5210 i8 &lt;len&gt;, i32 &lt;align&gt;)
5211 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5212 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5213 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5214 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5215 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5216 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5217</pre>
5218
5219<h5>Overview:</h5>
5220
5221<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5222The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5223byte value.
5224</p>
5225
5226<p>
5227Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
5228does not return a value, and takes an extra alignment argument.
5229</p>
5230
5231<h5>Arguments:</h5>
5232
5233<p>
5234The first argument is a pointer to the destination to fill, the second is the
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5235byte value to fill it with, the third argument is an integer
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5236argument specifying the number of bytes to fill, and the fourth argument is the
5237known alignment of destination location.
5238</p>
5239
5240<p>
5241If 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]5242the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5243</p>
5244
5245<h5>Semantics:</h5>
5246
5247<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5248The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
5249the
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5250destination location. If the argument is known to be aligned to some boundary,
5251this can be specified as the fourth argument, otherwise it should be set to 0 or
52521.
5253</p>
5254</div>
5255
5256
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5257<!-- _______________________________________________________________________ -->
5258<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5259 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5260</div>
5261
5262<div class="doc_text">
5263
5264<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5265<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]5266floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5267types however.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5268<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5269 declare float @llvm.sqrt.f32(float %Val)
5270 declare double @llvm.sqrt.f64(double %Val)
5271 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5272 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5273 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5274</pre>
5275
5276<h5>Overview:</h5>
5277
5278<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5279The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5280returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5281<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner103e2d72008-01-29 07:00:44 +0000[diff] [blame]5282negative numbers other than -0.0 (which allows for better optimization, because
5283there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
5284defined to return -0.0 like IEEE sqrt.
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5285</p>
5286
5287<h5>Arguments:</h5>
5288
5289<p>
5290The argument and return value are floating point numbers of the same type.
5291</p>
5292
5293<h5>Semantics:</h5>
5294
5295<p>
Dan Gohmand6257fe2007-07-16 14:37:41 +0000[diff] [blame]5296This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5297floating point number.
5298</p>
5299</div>
5300
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5301<!-- _______________________________________________________________________ -->
5302<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5303 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5304</div>
5305
5306<div class="doc_text">
5307
5308<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5309<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]5310floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5311types however.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5312<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5313 declare float @llvm.powi.f32(float %Val, i32 %power)
5314 declare double @llvm.powi.f64(double %Val, i32 %power)
5315 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5316 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5317 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5318</pre>
5319
5320<h5>Overview:</h5>
5321
5322<p>
5323The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5324specified (positive or negative) power. The order of evaluation of
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5325multiplications is not defined. When a vector of floating point type is
5326used, the second argument remains a scalar integer value.
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5327</p>
5328
5329<h5>Arguments:</h5>
5330
5331<p>
5332The second argument is an integer power, and the first is a value to raise to
5333that power.
5334</p>
5335
5336<h5>Semantics:</h5>
5337
5338<p>
5339This function returns the first value raised to the second power with an
5340unspecified sequence of rounding operations.</p>
5341</div>
5342
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5343<!-- _______________________________________________________________________ -->
5344<div class="doc_subsubsection">
5345 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5346</div>
5347
5348<div class="doc_text">
5349
5350<h5>Syntax:</h5>
5351<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5352floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5353types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5354<pre>
5355 declare float @llvm.sin.f32(float %Val)
5356 declare double @llvm.sin.f64(double %Val)
5357 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5358 declare fp128 @llvm.sin.f128(fp128 %Val)
5359 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5360</pre>
5361
5362<h5>Overview:</h5>
5363
5364<p>
5365The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
5366</p>
5367
5368<h5>Arguments:</h5>
5369
5370<p>
5371The argument and return value are floating point numbers of the same type.
5372</p>
5373
5374<h5>Semantics:</h5>
5375
5376<p>
5377This function returns the sine of the specified operand, returning the
5378same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5379conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5380</div>
5381
5382<!-- _______________________________________________________________________ -->
5383<div class="doc_subsubsection">
5384 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5385</div>
5386
5387<div class="doc_text">
5388
5389<h5>Syntax:</h5>
5390<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5391floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5392types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5393<pre>
5394 declare float @llvm.cos.f32(float %Val)
5395 declare double @llvm.cos.f64(double %Val)
5396 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5397 declare fp128 @llvm.cos.f128(fp128 %Val)
5398 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5399</pre>
5400
5401<h5>Overview:</h5>
5402
5403<p>
5404The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
5405</p>
5406
5407<h5>Arguments:</h5>
5408
5409<p>
5410The argument and return value are floating point numbers of the same type.
5411</p>
5412
5413<h5>Semantics:</h5>
5414
5415<p>
5416This function returns the cosine of the specified operand, returning the
5417same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5418conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5419</div>
5420
5421<!-- _______________________________________________________________________ -->
5422<div class="doc_subsubsection">
5423 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5424</div>
5425
5426<div class="doc_text">
5427
5428<h5>Syntax:</h5>
5429<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5430floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5431types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5432<pre>
5433 declare float @llvm.pow.f32(float %Val, float %Power)
5434 declare double @llvm.pow.f64(double %Val, double %Power)
5435 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5436 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5437 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5438</pre>
5439
5440<h5>Overview:</h5>
5441
5442<p>
5443The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5444specified (positive or negative) power.
5445</p>
5446
5447<h5>Arguments:</h5>
5448
5449<p>
5450The second argument is a floating point power, and the first is a value to
5451raise to that power.
5452</p>
5453
5454<h5>Semantics:</h5>
5455
5456<p>
5457This function returns the first value raised to the second power,
5458returning the
5459same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5460conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5461</div>
5462
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5463
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5464<!-- ======================================================================= -->
5465<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5466 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5467</div>
5468
5469<div class="doc_text">
5470<p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5471LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5472These allow efficient code generation for some algorithms.
5473</p>
5474
5475</div>
5476
5477<!-- _______________________________________________________________________ -->
5478<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5479 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5480</div>
5481
5482<div class="doc_text">
5483
5484<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5485<p>This is an overloaded intrinsic function. You can use bswap on any integer
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5486type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5487<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5488 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5489 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5490 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5491</pre>
5492
5493<h5>Overview:</h5>
5494
5495<p>
Reid Spencer338ea092007-04-02 02:25:19 +0000[diff] [blame]5496The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5497values with an even number of bytes (positive multiple of 16 bits). These are
5498useful for performing operations on data that is not in the target's native
5499byte order.
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5500</p>
5501
5502<h5>Semantics:</h5>
5503
5504<p>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5505The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5506and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
5507intrinsic returns an i32 value that has the four bytes of the input i32
5508swapped, 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]5509i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
5510<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5511additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5512</p>
5513
5514</div>
5515
5516<!-- _______________________________________________________________________ -->
5517<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5518 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5519</div>
5520
5521<div class="doc_text">
5522
5523<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5524<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]5525width. Not all targets support all bit widths however.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5526<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5527 declare i8 @llvm.ctpop.i8 (i8 &lt;src&gt;)
5528 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5529 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5530 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5531 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5532</pre>
5533
5534<h5>Overview:</h5>
5535
5536<p>
Chris Lattnerec6cb612006-01-16 22:38:59 +0000[diff] [blame]5537The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
5538value.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5539</p>
5540
5541<h5>Arguments:</h5>
5542
5543<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]5544The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5545integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5546</p>
5547
5548<h5>Semantics:</h5>
5549
5550<p>
5551The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
5552</p>
5553</div>
5554
5555<!-- _______________________________________________________________________ -->
5556<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5557 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5558</div>
5559
5560<div class="doc_text">
5561
5562<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5563<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]5564integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5565<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5566 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5567 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5568 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5569 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5570 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5571</pre>
5572
5573<h5>Overview:</h5>
5574
5575<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5576The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5577leading zeros in a variable.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5578</p>
5579
5580<h5>Arguments:</h5>
5581
5582<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]5583The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5584integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5585</p>
5586
5587<h5>Semantics:</h5>
5588
5589<p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5590The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
5591in 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]5592of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5593</p>
5594</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5595
5596
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5597
5598<!-- _______________________________________________________________________ -->
5599<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5600 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5601</div>
5602
5603<div class="doc_text">
5604
5605<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5606<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]5607integer bit width. Not all targets support all bit widths however.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5608<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5609 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5610 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5611 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5612 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5613 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5614</pre>
5615
5616<h5>Overview:</h5>
5617
5618<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5619The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5620trailing zeros.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5621</p>
5622
5623<h5>Arguments:</h5>
5624
5625<p>
5626The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5627integer type. The return type must match the argument type.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5628</p>
5629
5630<h5>Semantics:</h5>
5631
5632<p>
5633The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
5634in a variable. If the src == 0 then the result is the size in bits of the type
5635of src. For example, <tt>llvm.cttz(2) = 1</tt>.
5636</p>
5637</div>
5638
Reid Spencer497d93e2007-04-01 08:27:01 +0000[diff] [blame]5639<!-- _______________________________________________________________________ -->
5640<div class="doc_subsubsection">
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5641 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5642</div>
5643
5644<div class="doc_text">
5645
5646<h5>Syntax:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5647<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5648on any integer bit width.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5649<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5650 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
5651 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5652</pre>
5653
5654<h5>Overview:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5655<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5656range of bits from an integer value and returns them in the same bit width as
5657the original value.</p>
5658
5659<h5>Arguments:</h5>
5660<p>The first argument, <tt>%val</tt> and the result may be integer types of
5661any bit width but they must have the same bit width. The second and third
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5662arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5663
5664<h5>Semantics:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5665<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5666of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
5667<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
5668operates in forward mode.</p>
5669<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
5670right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5671only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
5672<ol>
5673 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
5674 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
5675 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
5676 to determine the number of bits to retain.</li>
5677 <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]5678 <li>The mask is ANDed with <tt>%val</tt> to produce the result.</li>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5679</ol>
Reid Spencerd6a85b52007-05-14 16:14:57 +0000[diff] [blame]5680<p>In reverse mode, a similar computation is made except that the bits are
5681returned in the reverse order. So, for example, if <tt>X</tt> has the value
5682<tt>i16 0x0ACF (101011001111)</tt> and we apply
5683<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
5684<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5685</div>
5686
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5687<div class="doc_subsubsection">
5688 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
5689</div>
5690
5691<div class="doc_text">
5692
5693<h5>Syntax:</h5>
5694<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5695on any integer bit width.</p>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5696<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5697 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
5698 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]5699</pre>
5700
5701<h5>Overview:</h5>
5702<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
5703of bits in an integer value with another integer value. It returns the integer
5704with the replaced bits.</p>
5705
5706<h5>Arguments:</h5>
5707<p>The first argument, <tt>%val</tt> and the result may be integer types of
5708any bit width but they must have the same bit width. <tt>%val</tt> is the value
5709whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
5710integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
5711type since they specify only a bit index.</p>
5712
5713<h5>Semantics:</h5>
5714<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
5715of operation: forwards and reverse. If <tt>%lo</tt> is greater than
5716<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
5717operates in forward mode.</p>
5718<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
5719truncating it down to the size of the replacement area or zero extending it
5720up to that size.</p>
5721<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5722are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5723in <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]5724to the <tt>%hi</tt>th bit.</p>
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5725<p>In reverse mode, a similar computation is made except that the bits are
5726reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5727<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]5728<h5>Examples:</h5>
5729<pre>
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5730 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5731 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5732 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5733 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5734 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]5735</pre>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5736</div>
5737
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5738<!-- ======================================================================= -->
5739<div class="doc_subsection">
5740 <a name="int_debugger">Debugger Intrinsics</a>
5741</div>
5742
5743<div class="doc_text">
5744<p>
5745The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
5746are described in the <a
5747href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
5748Debugging</a> document.
5749</p>
5750</div>
5751
5752
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]5753<!-- ======================================================================= -->
5754<div class="doc_subsection">
5755 <a name="int_eh">Exception Handling Intrinsics</a>
5756</div>
5757
5758<div class="doc_text">
5759<p> The LLVM exception handling intrinsics (which all start with
5760<tt>llvm.eh.</tt> prefix), are described in the <a
5761href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
5762Handling</a> document. </p>
5763</div>
5764
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5765<!-- ======================================================================= -->
5766<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5767 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5768</div>
5769
5770<div class="doc_text">
5771<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5772 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5773 the <tt>nest</tt> attribute, from a function. The result is a callable
5774 function pointer lacking the nest parameter - the caller does not need
5775 to provide a value for it. Instead, the value to use is stored in
5776 advance in a "trampoline", a block of memory usually allocated
5777 on the stack, which also contains code to splice the nest value into the
5778 argument list. This is used to implement the GCC nested function address
5779 extension.
5780</p>
5781<p>
5782 For example, if the function is
5783 <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]5784 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]5785<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5786 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
5787 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
5788 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
5789 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5790</pre>
Bill Wendling03295ca2007-09-22 09:23:55 +0000[diff] [blame]5791 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
5792 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5793</div>
5794
5795<!-- _______________________________________________________________________ -->
5796<div class="doc_subsubsection">
5797 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
5798</div>
5799<div class="doc_text">
5800<h5>Syntax:</h5>
5801<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5802declare 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]5803</pre>
5804<h5>Overview:</h5>
5805<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5806 This fills the memory pointed to by <tt>tramp</tt> with code
5807 and returns a function pointer suitable for executing it.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5808</p>
5809<h5>Arguments:</h5>
5810<p>
5811 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
5812 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
5813 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsc00c2ba2007-08-22 23:39:54 +0000[diff] [blame]5814 intrinsic. Note that the size and the alignment are target-specific - LLVM
5815 currently provides no portable way of determining them, so a front-end that
5816 generates this intrinsic needs to have some target-specific knowledge.
5817 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]5818</p>
5819<h5>Semantics:</h5>
5820<p>
5821 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5822 dependent code, turning it into a function. A pointer to this function is
5823 returned, but needs to be bitcast to an
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5824 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5825 before being called. The new function's signature is the same as that of
5826 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
5827 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
5828 of pointer type. Calling the new function is equivalent to calling
5829 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
5830 missing <tt>nest</tt> argument. If, after calling
5831 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
5832 modified, then the effect of any later call to the returned function pointer is
5833 undefined.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5834</p>
5835</div>
5836
5837<!-- ======================================================================= -->
5838<div class="doc_subsection">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]5839 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
5840</div>
5841
5842<div class="doc_text">
5843<p>
5844 These intrinsic functions expand the "universal IR" of LLVM to represent
5845 hardware constructs for atomic operations and memory synchronization. This
5846 provides an interface to the hardware, not an interface to the programmer. It
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5847 is aimed at a low enough level to allow any programming models or APIs
5848 (Application Programming Interfaces) which
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]5849 need atomic behaviors to map cleanly onto it. It is also modeled primarily on
5850 hardware behavior. Just as hardware provides a "universal IR" for source
5851 languages, it also provides a starting point for developing a "universal"
5852 atomic operation and synchronization IR.
5853</p>
5854<p>
5855 These do <em>not</em> form an API such as high-level threading libraries,
5856 software transaction memory systems, atomic primitives, and intrinsic
5857 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
5858 application libraries. The hardware interface provided by LLVM should allow
5859 a clean implementation of all of these APIs and parallel programming models.
5860 No one model or paradigm should be selected above others unless the hardware
5861 itself ubiquitously does so.
5862
5863</p>
5864</div>
5865
5866<!-- _______________________________________________________________________ -->
5867<div class="doc_subsubsection">
5868 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
5869</div>
5870<div class="doc_text">
5871<h5>Syntax:</h5>
5872<pre>
5873declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;,
5874i1 &lt;device&gt; )
5875
5876</pre>
5877<h5>Overview:</h5>
5878<p>
5879 The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
5880 specific pairs of memory access types.
5881</p>
5882<h5>Arguments:</h5>
5883<p>
5884 The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
5885 The first four arguments enables a specific barrier as listed below. The fith
5886 argument specifies that the barrier applies to io or device or uncached memory.
5887
5888</p>
5889 <ul>
5890 <li><tt>ll</tt>: load-load barrier</li>
5891 <li><tt>ls</tt>: load-store barrier</li>
5892 <li><tt>sl</tt>: store-load barrier</li>
5893 <li><tt>ss</tt>: store-store barrier</li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5894 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]5895 </ul>
5896<h5>Semantics:</h5>
5897<p>
5898 This intrinsic causes the system to enforce some ordering constraints upon
5899 the loads and stores of the program. This barrier does not indicate
5900 <em>when</em> any events will occur, it only enforces an <em>order</em> in
5901 which they occur. For any of the specified pairs of load and store operations
5902 (f.ex. load-load, or store-load), all of the first operations preceding the
5903 barrier will complete before any of the second operations succeeding the
5904 barrier begin. Specifically the semantics for each pairing is as follows:
5905</p>
5906 <ul>
5907 <li><tt>ll</tt>: All loads before the barrier must complete before any load
5908 after the barrier begins.</li>
5909
5910 <li><tt>ls</tt>: All loads before the barrier must complete before any
5911 store after the barrier begins.</li>
5912 <li><tt>ss</tt>: All stores before the barrier must complete before any
5913 store after the barrier begins.</li>
5914 <li><tt>sl</tt>: All stores before the barrier must complete before any
5915 load after the barrier begins.</li>
5916 </ul>
5917<p>
5918 These semantics are applied with a logical "and" behavior when more than one
5919 is enabled in a single memory barrier intrinsic.
5920</p>
5921<p>
5922 Backends may implement stronger barriers than those requested when they do not
5923 support as fine grained a barrier as requested. Some architectures do not
5924 need all types of barriers and on such architectures, these become noops.
5925</p>
5926<h5>Example:</h5>
5927<pre>
5928%ptr = malloc i32
5929 store i32 4, %ptr
5930
5931%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
5932 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
5933 <i>; guarantee the above finishes</i>
5934 store i32 8, %ptr <i>; before this begins</i>
5935</pre>
5936</div>
5937
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5938<!-- _______________________________________________________________________ -->
5939<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]5940 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5941</div>
5942<div class="doc_text">
5943<h5>Syntax:</h5>
5944<p>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]5945 This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
5946 any integer bit width and for different address spaces. Not all targets
5947 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5948
5949<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]5950declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
5951declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
5952declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
5953declare 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]5954
5955</pre>
5956<h5>Overview:</h5>
5957<p>
5958 This loads a value in memory and compares it to a given value. If they are
5959 equal, it stores a new value into the memory.
5960</p>
5961<h5>Arguments:</h5>
5962<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]5963 The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5964 well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
5965 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
5966 this integer type. While any bit width integer may be used, targets may only
5967 lower representations they support in hardware.
5968
5969</p>
5970<h5>Semantics:</h5>
5971<p>
5972 This entire intrinsic must be executed atomically. It first loads the value
5973 in memory pointed to by <tt>ptr</tt> and compares it with the value
5974 <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
5975 loaded value is yielded in all cases. This provides the equivalent of an
5976 atomic compare-and-swap operation within the SSA framework.
5977</p>
5978<h5>Examples:</h5>
5979
5980<pre>
5981%ptr = malloc i32
5982 store i32 4, %ptr
5983
5984%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]5985%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5986 <i>; yields {i32}:result1 = 4</i>
5987%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
5988%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
5989
5990%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]5991%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5992 <i>; yields {i32}:result2 = 8</i>
5993%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
5994
5995%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
5996</pre>
5997</div>
5998
5999<!-- _______________________________________________________________________ -->
6000<div class="doc_subsubsection">
6001 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6002</div>
6003<div class="doc_text">
6004<h5>Syntax:</h5>
6005
6006<p>
6007 This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6008 integer bit width. Not all targets support all bit widths however.</p>
6009<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6010declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6011declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6012declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6013declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6014
6015</pre>
6016<h5>Overview:</h5>
6017<p>
6018 This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6019 the value from memory. It then stores the value in <tt>val</tt> in the memory
6020 at <tt>ptr</tt>.
6021</p>
6022<h5>Arguments:</h5>
6023
6024<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6025 The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6026 <tt>val</tt> argument and the result must be integers of the same bit width.
6027 The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6028 integer type. The targets may only lower integer representations they
6029 support.
6030</p>
6031<h5>Semantics:</h5>
6032<p>
6033 This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6034 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6035 equivalent of an atomic swap operation within the SSA framework.
6036
6037</p>
6038<h5>Examples:</h5>
6039<pre>
6040%ptr = malloc i32
6041 store i32 4, %ptr
6042
6043%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6044%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6045 <i>; yields {i32}:result1 = 4</i>
6046%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6047%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6048
6049%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6050%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6051 <i>; yields {i32}:result2 = 8</i>
6052
6053%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6054%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6055</pre>
6056</div>
6057
6058<!-- _______________________________________________________________________ -->
6059<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6060 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6061
6062</div>
6063<div class="doc_text">
6064<h5>Syntax:</h5>
6065<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6066 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]6067 integer bit width. Not all targets support all bit widths however.</p>
6068<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6069declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6070declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6071declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6072declare 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]6073
6074</pre>
6075<h5>Overview:</h5>
6076<p>
6077 This intrinsic adds <tt>delta</tt> to the value stored in memory at
6078 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6079</p>
6080<h5>Arguments:</h5>
6081<p>
6082
6083 The intrinsic takes two arguments, the first a pointer to an integer value
6084 and the second an integer value. The result is also an integer value. These
6085 integer types can have any bit width, but they must all have the same bit
6086 width. The targets may only lower integer representations they support.
6087</p>
6088<h5>Semantics:</h5>
6089<p>
6090 This intrinsic does a series of operations atomically. It first loads the
6091 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6092 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6093</p>
6094
6095<h5>Examples:</h5>
6096<pre>
6097%ptr = malloc i32
6098 store i32 4, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6099%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6100 <i>; yields {i32}:result1 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6101%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6102 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6103%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6104 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6105%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6106</pre>
6107</div>
6108
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6109<!-- _______________________________________________________________________ -->
6110<div class="doc_subsubsection">
6111 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6112
6113</div>
6114<div class="doc_text">
6115<h5>Syntax:</h5>
6116<p>
6117 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]6118 any integer bit width and for different address spaces. Not all targets
6119 support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6120<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6121declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6122declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6123declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6124declare 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]6125
6126</pre>
6127<h5>Overview:</h5>
6128<p>
6129 This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6130 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6131</p>
6132<h5>Arguments:</h5>
6133<p>
6134
6135 The intrinsic takes two arguments, the first a pointer to an integer value
6136 and the second an integer value. The result is also an integer value. These
6137 integer types can have any bit width, but they must all have the same bit
6138 width. The targets may only lower integer representations they support.
6139</p>
6140<h5>Semantics:</h5>
6141<p>
6142 This intrinsic does a series of operations atomically. It first loads the
6143 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6144 result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6145</p>
6146
6147<h5>Examples:</h5>
6148<pre>
6149%ptr = malloc i32
6150 store i32 8, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6151%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6152 <i>; yields {i32}:result1 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6153%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6154 <i>; yields {i32}:result2 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6155%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6156 <i>; yields {i32}:result3 = 2</i>
6157%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6158</pre>
6159</div>
6160
6161<!-- _______________________________________________________________________ -->
6162<div class="doc_subsubsection">
6163 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6164 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6165 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6166 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
6167
6168</div>
6169<div class="doc_text">
6170<h5>Syntax:</h5>
6171<p>
6172 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
6173 <tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6174 <tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
6175 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6176<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6177declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6178declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6179declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6180declare 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]6181
6182</pre>
6183
6184<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6185declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6186declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6187declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6188declare 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]6189
6190</pre>
6191
6192<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6193declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6194declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6195declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6196declare 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]6197
6198</pre>
6199
6200<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6201declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6202declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6203declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6204declare 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]6205
6206</pre>
6207<h5>Overview:</h5>
6208<p>
6209 These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6210 the value stored in memory at <tt>ptr</tt>. It yields the original value
6211 at <tt>ptr</tt>.
6212</p>
6213<h5>Arguments:</h5>
6214<p>
6215
6216 These intrinsics take two arguments, the first a pointer to an integer value
6217 and the second an integer value. The result is also an integer value. These
6218 integer types can have any bit width, but they must all have the same bit
6219 width. The targets may only lower integer representations they support.
6220</p>
6221<h5>Semantics:</h5>
6222<p>
6223 These intrinsics does a series of operations atomically. They first load the
6224 value stored at <tt>ptr</tt>. They then do the bitwise operation
6225 <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
6226 value stored at <tt>ptr</tt>.
6227</p>
6228
6229<h5>Examples:</h5>
6230<pre>
6231%ptr = malloc i32
6232 store i32 0x0F0F, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6233%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6234 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6235%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6236 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6237%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6238 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6239%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6240 <i>; yields {i32}:result3 = FF</i>
6241%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6242</pre>
6243</div>
6244
6245
6246<!-- _______________________________________________________________________ -->
6247<div class="doc_subsubsection">
6248 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6249 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6250 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6251 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
6252
6253</div>
6254<div class="doc_text">
6255<h5>Syntax:</h5>
6256<p>
6257 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6258 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6259 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6260 address spaces. Not all targets
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6261 support all bit widths however.</p>
6262<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6263declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6264declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6265declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6266declare 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]6267
6268</pre>
6269
6270<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6271declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6272declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6273declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6274declare 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]6275
6276</pre>
6277
6278<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6279declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6280declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6281declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6282declare 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]6283
6284</pre>
6285
6286<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6287declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6288declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6289declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6290declare 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]6291
6292</pre>
6293<h5>Overview:</h5>
6294<p>
6295 These intrinsics takes the signed or unsigned minimum or maximum of
6296 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6297 original value at <tt>ptr</tt>.
6298</p>
6299<h5>Arguments:</h5>
6300<p>
6301
6302 These intrinsics take two arguments, the first a pointer to an integer value
6303 and the second an integer value. The result is also an integer value. These
6304 integer types can have any bit width, but they must all have the same bit
6305 width. The targets may only lower integer representations they support.
6306</p>
6307<h5>Semantics:</h5>
6308<p>
6309 These intrinsics does a series of operations atomically. They first load the
6310 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
6311 <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
6312 the original value stored at <tt>ptr</tt>.
6313</p>
6314
6315<h5>Examples:</h5>
6316<pre>
6317%ptr = malloc i32
6318 store i32 7, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6319%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6320 <i>; yields {i32}:result0 = 7</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6321%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6322 <i>; yields {i32}:result1 = -2</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6323%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6324 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6325%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6326 <i>; yields {i32}:result3 = 8</i>
6327%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6328</pre>
6329</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6330
6331<!-- ======================================================================= -->
6332<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6333 <a name="int_general">General Intrinsics</a>
6334</div>
6335
6336<div class="doc_text">
6337<p> This class of intrinsics is designed to be generic and has
6338no specific purpose. </p>
6339</div>
6340
6341<!-- _______________________________________________________________________ -->
6342<div class="doc_subsubsection">
6343 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6344</div>
6345
6346<div class="doc_text">
6347
6348<h5>Syntax:</h5>
6349<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]6350 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]6351</pre>
6352
6353<h5>Overview:</h5>
6354
6355<p>
6356The '<tt>llvm.var.annotation</tt>' intrinsic
6357</p>
6358
6359<h5>Arguments:</h5>
6360
6361<p>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]6362The first argument is a pointer to a value, the second is a pointer to a
6363global string, the third is a pointer to a global string which is the source
6364file name, and the last argument is the line number.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6365</p>
6366
6367<h5>Semantics:</h5>
6368
6369<p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6370This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6371This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6372annotations. These have no other defined use, they are ignored by code
6373generation and optimization.
6374</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6375</div>
6376
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6377<!-- _______________________________________________________________________ -->
6378<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]6379 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6380</div>
6381
6382<div class="doc_text">
6383
6384<h5>Syntax:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6385<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6386any integer bit width.
6387</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6388<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]6389 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6390 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6391 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6392 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6393 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]6394</pre>
6395
6396<h5>Overview:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6397
6398<p>
6399The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6400</p>
6401
6402<h5>Arguments:</h5>
6403
6404<p>
6405The first argument is an integer value (result of some expression),
6406the second is a pointer to a global string, the third is a pointer to a global
6407string which is the source file name, and the last argument is the line number.
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6408It returns the value of the first argument.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6409</p>
6410
6411<h5>Semantics:</h5>
6412
6413<p>
6414This intrinsic allows annotations to be put on arbitrary expressions
6415with arbitrary strings. This can be useful for special purpose optimizations
6416that want to look for these annotations. These have no other defined use, they
6417are ignored by code generation and optimization.
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6418</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6419</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6420
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6421<!-- _______________________________________________________________________ -->
6422<div class="doc_subsubsection">
6423 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6424</div>
6425
6426<div class="doc_text">
6427
6428<h5>Syntax:</h5>
6429<pre>
6430 declare void @llvm.trap()
6431</pre>
6432
6433<h5>Overview:</h5>
6434
6435<p>
6436The '<tt>llvm.trap</tt>' intrinsic
6437</p>
6438
6439<h5>Arguments:</h5>
6440
6441<p>
6442None
6443</p>
6444
6445<h5>Semantics:</h5>
6446
6447<p>
6448This intrinsics is lowered to the target dependent trap instruction. If the
6449target does not have a trap instruction, this intrinsic will be lowered to the
6450call of the abort() function.
6451</p>
6452</div>
6453
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6454<!-- _______________________________________________________________________ -->
6455<div class="doc_subsubsection">
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]6456 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6457</div>
6458<div class="doc_text">
6459<h5>Syntax:</h5>
6460<pre>
6461declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
6462
6463</pre>
6464<h5>Overview:</h5>
6465<p>
6466 The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
6467 it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
6468 it is placed on the stack before local variables.
6469</p>
6470<h5>Arguments:</h5>
6471<p>
6472 The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
6473 first argument is the value loaded from the stack guard
6474 <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
6475 has enough space to hold the value of the guard.
6476</p>
6477<h5>Semantics:</h5>
6478<p>
6479 This intrinsic causes the prologue/epilogue inserter to force the position of
6480 the <tt>AllocaInst</tt> stack slot to be before local variables on the
6481 stack. This is to ensure that if a local variable on the stack is overwritten,
6482 it will destroy the value of the guard. When the function exits, the guard on
6483 the stack is checked against the original guard. If they're different, then
6484 the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
6485</p>
6486</div>
6487
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6488<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6489<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6490<address>
6491 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
6492 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
6493 <a href="http://validator.w3.org/check/referer"><img
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]6494 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6495
6496 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]6497 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6498 Last modified: $Date$
6499</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]6500
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6501</body>
6502</html>