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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 69e4adb22e43f15bf96803c86f8466e3ba84cade / . / 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
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]568<p><a name="linkage_external"></a>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>
Owen Anderson117bbd32008-02-18 04:09:01 +0000[diff] [blame]893 <dd>This indicates that the parameter does not alias any global or any other
894 parameter. The caller is responsible for ensuring that this is the case,
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]895 usually by placing the value in a stack allocation. This is not a valid
896 attribute for return values.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]897
Duncan Sands50f19f52007-07-27 19:57:41 +0000[diff] [blame]898 <dt><tt>nest</tt></dt>
Duncan Sands0789b8b2008-07-08 09:27:25 +0000[diff] [blame]899 <dd>This indicates that the pointer parameter can be excised using the
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]900 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
901 attribute for return values.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]902 </dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]903
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]904</div>
905
906<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]907<div class="doc_subsection">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]908 <a name="gc">Garbage Collector Names</a>
909</div>
910
911<div class="doc_text">
912<p>Each function may specify a garbage collector name, which is simply a
913string.</p>
914
915<div class="doc_code"><pre
916>define void @f() gc "name" { ...</pre></div>
917
918<p>The compiler declares the supported values of <i>name</i>. Specifying a
919collector which will cause the compiler to alter its output in order to support
920the named garbage collection algorithm.</p>
921</div>
922
923<!-- ======================================================================= -->
924<div class="doc_subsection">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]925 <a name="fnattrs">Function Attributes</a>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]926</div>
927
928<div class="doc_text">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]929
930<p>Function attributes are set to communicate additional information about
931 a function. Function attributes are considered to be part of the function,
932 not of the function type, so functions with different parameter attributes
933 can have the same function type.</p>
934
935 <p>Function attributes are simple keywords that follow the type specified. If
936 multiple attributes are needed, they are space separated. For
937 example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]938
939<div class="doc_code">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]940<pre>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]941define void @f() noinline { ... }
942define void @f() alwaysinline { ... }
943define void @f() alwaysinline optsize { ... }
944define void @f() optsize
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]945</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]946</div>
947
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]948<dl>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]949<dt><tt>alwaysinline</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]950<dd>This attribute indicates that the inliner should attempt to inline this
951function into callers whenever possible, ignoring any active inlining size
952threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]953
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]954<dt><tt>noinline</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]955<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner94b5f7d2008-10-05 17:14:59 +0000[diff] [blame]956in any situation. This attribute may not be used together with the
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]957<tt>alwaysinline</tt> attribute.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]958
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]959<dt><tt>optsize</tt></dt>
Devang Patel66c6c652008-09-29 18:34:44 +0000[diff] [blame]960<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]961make choices that keep the code size of this function low, and otherwise do
962optimizations specifically to reduce code size.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]963
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]964<dt><tt>noreturn</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]965<dd>This function attribute indicates that the function never returns normally.
966This produces undefined behavior at runtime if the function ever does
967dynamically return.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]968
969<dt><tt>nounwind</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]970<dd>This function attribute indicates that the function never returns with an
971unwind or exceptional control flow. If the function does unwind, its runtime
972behavior is undefined.</dd>
973
974<dt><tt>readnone</tt></dt>
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]975<dd>This attribute indicates that the function computes its result (or the
976exception it throws) based strictly on its arguments, without dereferencing any
977pointer arguments or otherwise accessing any mutable state (e.g. memory, control
978registers, etc) visible to caller functions. It does not write through any
979pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
980never changes any state visible to callers.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]981
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]982<dt><tt><a name="readonly">readonly</a></tt></dt>
983<dd>This attribute indicates that the function does not write through any
984pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
985or otherwise modify any state (e.g. memory, control registers, etc) visible to
986caller functions. It may dereference pointer arguments and read state that may
987be set in the caller. A readonly function always returns the same value (or
988throws the same exception) when called with the same set of arguments and global
989state.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]990
991<dt><tt><a name="ssp">ssp</a></tt></dt>
992<dd>This attribute indicates that the function should emit a stack smashing
993protector. It is in the form of a "canary"&mdash;a random value placed on the
994stack before the local variables that's checked upon return from the function to
995see if it has been overwritten. A heuristic is used to determine if a function
996needs stack protectors or not.</dd>
997
998<dt><tt>ssp-req</tt></dt>
999<dd>This attribute indicates that the function should <em>always</em> emit a
1000stack smashing protector. This overrides the <tt><a href="#ssp">ssp</a></tt>
1001function attribute.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1002</dl>
1003
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1004</div>
1005
1006<!-- ======================================================================= -->
1007<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1008 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1009</div>
1010
1011<div class="doc_text">
1012<p>
1013Modules may contain "module-level inline asm" blocks, which corresponds to the
1014GCC "file scope inline asm" blocks. These blocks are internally concatenated by
1015LLVM and treated as a single unit, but may be separated in the .ll file if
1016desired. The syntax is very simple:
1017</p>
1018
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1019<div class="doc_code">
1020<pre>
1021module asm "inline asm code goes here"
1022module asm "more can go here"
1023</pre>
1024</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1025
1026<p>The strings can contain any character by escaping non-printable characters.
1027 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
1028 for the number.
1029</p>
1030
1031<p>
1032 The inline asm code is simply printed to the machine code .s file when
1033 assembly code is generated.
1034</p>
1035</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1036
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1037<!-- ======================================================================= -->
1038<div class="doc_subsection">
1039 <a name="datalayout">Data Layout</a>
1040</div>
1041
1042<div class="doc_text">
1043<p>A module may specify a target specific data layout string that specifies how
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]1044data is to be laid out in memory. The syntax for the data layout is simply:</p>
1045<pre> target datalayout = "<i>layout specification</i>"</pre>
1046<p>The <i>layout specification</i> consists of a list of specifications
1047separated by the minus sign character ('-'). Each specification starts with a
1048letter and may include other information after the letter to define some
1049aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1050<dl>
1051 <dt><tt>E</tt></dt>
1052 <dd>Specifies that the target lays out data in big-endian form. That is, the
1053 bits with the most significance have the lowest address location.</dd>
1054 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1055 <dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1056 the bits with the least significance have the lowest address location.</dd>
1057 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1058 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
1059 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
1060 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
1061 too.</dd>
1062 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1063 <dd>This specifies the alignment for an integer type of a given bit
1064 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1065 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1066 <dd>This specifies the alignment for a vector type of a given bit
1067 <i>size</i>.</dd>
1068 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1069 <dd>This specifies the alignment for a floating point type of a given bit
1070 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1071 (double).</dd>
1072 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1073 <dd>This specifies the alignment for an aggregate type of a given bit
1074 <i>size</i>.</dd>
1075</dl>
1076<p>When constructing the data layout for a given target, LLVM starts with a
1077default set of specifications which are then (possibly) overriden by the
1078specifications in the <tt>datalayout</tt> keyword. The default specifications
1079are given in this list:</p>
1080<ul>
1081 <li><tt>E</tt> - big endian</li>
1082 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1083 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1084 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1085 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1086 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1087 <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]1088 alignment of 64-bits</li>
1089 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1090 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1091 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1092 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1093 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
1094</ul>
Chris Lattnerebec6782008-08-05 18:21:08 +0000[diff] [blame]1095<p>When LLVM is determining the alignment for a given type, it uses the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1096following rules:</p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1097<ol>
1098 <li>If the type sought is an exact match for one of the specifications, that
1099 specification is used.</li>
1100 <li>If no match is found, and the type sought is an integer type, then the
1101 smallest integer type that is larger than the bitwidth of the sought type is
1102 used. If none of the specifications are larger than the bitwidth then the the
1103 largest integer type is used. For example, given the default specifications
1104 above, the i7 type will use the alignment of i8 (next largest) while both
1105 i65 and i256 will use the alignment of i64 (largest specified).</li>
1106 <li>If no match is found, and the type sought is a vector type, then the
1107 largest vector type that is smaller than the sought vector type will be used
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1108 as a fall back. This happens because &lt;128 x double&gt; can be implemented
1109 in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1110</ol>
1111</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1112
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1113<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1114<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1115<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1116
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1117<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1118
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1119<p>The LLVM type system is one of the most important features of the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1120intermediate representation. Being typed enables a number of
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1121optimizations to be performed on the intermediate representation directly,
1122without having to do
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1123extra analyses on the side before the transformation. A strong type
1124system makes it easier to read the generated code and enables novel
1125analyses and transformations that are not feasible to perform on normal
1126three address code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1127
1128</div>
1129
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1130<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1131<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1132Classifications</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1133<div class="doc_text">
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1134<p>The types fall into a few useful
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1135classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1136
1137<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1138 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1139 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1140 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1141 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1142 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1143 </tr>
1144 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1145 <td><a href="#t_floating">floating point</a></td>
1146 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1147 </tr>
1148 <tr>
1149 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1150 <td><a href="#t_integer">integer</a>,
1151 <a href="#t_floating">floating point</a>,
1152 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1153 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1154 <a href="#t_struct">structure</a>,
1155 <a href="#t_array">array</a>,
Dan Gohmanade5faa2008-05-23 22:50:26 +0000[diff] [blame]1156 <a href="#t_label">label</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1157 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1158 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1159 <tr>
1160 <td><a href="#t_primitive">primitive</a></td>
1161 <td><a href="#t_label">label</a>,
1162 <a href="#t_void">void</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1163 <a href="#t_floating">floating point</a>.</td>
1164 </tr>
1165 <tr>
1166 <td><a href="#t_derived">derived</a></td>
1167 <td><a href="#t_integer">integer</a>,
1168 <a href="#t_array">array</a>,
1169 <a href="#t_function">function</a>,
1170 <a href="#t_pointer">pointer</a>,
1171 <a href="#t_struct">structure</a>,
1172 <a href="#t_pstruct">packed structure</a>,
1173 <a href="#t_vector">vector</a>,
1174 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1175 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1176 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1177 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1178</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1179
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1180<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1181most important. Values of these types are the only ones which can be
1182produced by instructions, passed as arguments, or used as operands to
Dan Gohmanc4b49eb2008-05-23 21:53:15 +0000[diff] [blame]1183instructions.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1184</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1185
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1186<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1187<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1188
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1189<div class="doc_text">
1190<p>The primitive types are the fundamental building blocks of the LLVM
1191system.</p>
1192
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1193</div>
1194
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1195<!-- _______________________________________________________________________ -->
1196<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1197
1198<div class="doc_text">
1199 <table>
1200 <tbody>
1201 <tr><th>Type</th><th>Description</th></tr>
1202 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1203 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1204 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1205 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1206 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1207 </tbody>
1208 </table>
1209</div>
1210
1211<!-- _______________________________________________________________________ -->
1212<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1213
1214<div class="doc_text">
1215<h5>Overview:</h5>
1216<p>The void type does not represent any value and has no size.</p>
1217
1218<h5>Syntax:</h5>
1219
1220<pre>
1221 void
1222</pre>
1223</div>
1224
1225<!-- _______________________________________________________________________ -->
1226<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1227
1228<div class="doc_text">
1229<h5>Overview:</h5>
1230<p>The label type represents code labels.</p>
1231
1232<h5>Syntax:</h5>
1233
1234<pre>
1235 label
1236</pre>
1237</div>
1238
1239
1240<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1241<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1242
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1243<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1244
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1245<p>The real power in LLVM comes from the derived types in the system.
1246This is what allows a programmer to represent arrays, functions,
1247pointers, and other useful types. Note that these derived types may be
1248recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1249
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1250</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1251
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1252<!-- _______________________________________________________________________ -->
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1253<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1254
1255<div class="doc_text">
1256
1257<h5>Overview:</h5>
1258<p>The integer type is a very simple derived type that simply specifies an
1259arbitrary bit width for the integer type desired. Any bit width from 1 bit to
12602^23-1 (about 8 million) can be specified.</p>
1261
1262<h5>Syntax:</h5>
1263
1264<pre>
1265 iN
1266</pre>
1267
1268<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1269value.</p>
1270
1271<h5>Examples:</h5>
1272<table class="layout">
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]1273 <tbody>
1274 <tr>
1275 <td><tt>i1</tt></td>
1276 <td>a single-bit integer.</td>
1277 </tr><tr>
1278 <td><tt>i32</tt></td>
1279 <td>a 32-bit integer.</td>
1280 </tr><tr>
1281 <td><tt>i1942652</tt></td>
1282 <td>a really big integer of over 1 million bits.</td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1283 </tr>
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]1284 </tbody>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1285</table>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1286</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1287
1288<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1289<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1290
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1291<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1292
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1293<h5>Overview:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1294
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1295<p>The array type is a very simple derived type that arranges elements
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1296sequentially in memory. The array type requires a size (number of
1297elements) and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1298
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1299<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1300
1301<pre>
1302 [&lt;# elements&gt; x &lt;elementtype&gt;]
1303</pre>
1304
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1305<p>The number of elements is a constant integer value; elementtype may
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1306be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1307
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1308<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1309<table class="layout">
1310 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1311 <td class="left"><tt>[40 x i32]</tt></td>
1312 <td class="left">Array of 40 32-bit integer values.</td>
1313 </tr>
1314 <tr class="layout">
1315 <td class="left"><tt>[41 x i32]</tt></td>
1316 <td class="left">Array of 41 32-bit integer values.</td>
1317 </tr>
1318 <tr class="layout">
1319 <td class="left"><tt>[4 x i8]</tt></td>
1320 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1321 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1322</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1323<p>Here are some examples of multidimensional arrays:</p>
1324<table class="layout">
1325 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1326 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1327 <td class="left">3x4 array of 32-bit integer values.</td>
1328 </tr>
1329 <tr class="layout">
1330 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1331 <td class="left">12x10 array of single precision floating point values.</td>
1332 </tr>
1333 <tr class="layout">
1334 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1335 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1336 </tr>
1337</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1338
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1339<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1340length array. Normally, accesses past the end of an array are undefined in
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1341LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1342As a special case, however, zero length arrays are recognized to be variable
1343length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1344type "{ i32, [0 x float]}", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1345
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1346</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1347
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1348<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1349<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1350<div class="doc_text">
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1351
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1352<h5>Overview:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1353
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1354<p>The function type can be thought of as a function signature. It
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1355consists of a return type and a list of formal parameter types. The
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1356return 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]1357If 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]1358class types, and the struct must have at least one element.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1359
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1360<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1361
1362<pre>
1363 &lt;returntype list&gt; (&lt;parameter list&gt;)
1364</pre>
1365
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1366<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]1367specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1368which indicates that the function takes a variable number of arguments.
1369Variable argument functions can access their arguments with the <a
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1370 href="#int_varargs">variable argument handling intrinsic</a> functions.
1371'<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1372<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1373
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1374<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1375<table class="layout">
1376 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1377 <td class="left"><tt>i32 (i32)</tt></td>
1378 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1379 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1380 </tr><tr class="layout">
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]1381 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1382 </tt></td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1383 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1384 an <tt>i16</tt> that should be sign extended and a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1385 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1386 <tt>float</tt>.
1387 </td>
1388 </tr><tr class="layout">
1389 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1390 <td class="left">A vararg function that takes at least one
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1391 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1392 which returns an integer. This is the signature for <tt>printf</tt> in
1393 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1394 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1395 </tr><tr class="layout">
1396 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Devang Patel3a5bff82008-03-24 18:10:52 +0000[diff] [blame]1397 <td class="left">A function taking an <tt>i32></tt>, returning two
1398 <tt> i32 </tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1399 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1400 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1401</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1402
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1403</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1404<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1405<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1406<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1407<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1408<p>The structure type is used to represent a collection of data members
1409together in memory. The packing of the field types is defined to match
1410the ABI of the underlying processor. The elements of a structure may
1411be any type that has a size.</p>
1412<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1413and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1414field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1415instruction.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1416<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1417<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1418<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1419<table class="layout">
1420 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1421 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1422 <td class="left">A triple of three <tt>i32</tt> values</td>
1423 </tr><tr class="layout">
1424 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1425 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1426 second element is a <a href="#t_pointer">pointer</a> to a
1427 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1428 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1429 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1430</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1431</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1432
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1433<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1434<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1435</div>
1436<div class="doc_text">
1437<h5>Overview:</h5>
1438<p>The packed structure type is used to represent a collection of data members
1439together in memory. There is no padding between fields. Further, the alignment
1440of a packed structure is 1 byte. The elements of a packed structure may
1441be any type that has a size.</p>
1442<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1443and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1444field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1445instruction.</p>
1446<h5>Syntax:</h5>
1447<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1448<h5>Examples:</h5>
1449<table class="layout">
1450 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1451 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1452 <td class="left">A triple of three <tt>i32</tt> values</td>
1453 </tr><tr class="layout">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1454 <td class="left">
1455<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1456 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1457 second element is a <a href="#t_pointer">pointer</a> to a
1458 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1459 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1460 </tr>
1461</table>
1462</div>
1463
1464<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1465<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1466<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1467<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1468<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]1469reference to another object, which must live in memory. Pointer types may have
1470an optional address space attribute defining the target-specific numbered
1471address space where the pointed-to object resides. The default address space is
1472zero.</p>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1473<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1474<pre> &lt;type&gt; *<br></pre>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1475<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1476<table class="layout">
1477 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1478 <td class="left"><tt>[4x i32]*</tt></td>
1479 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1480 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1481 </tr>
1482 <tr class="layout">
1483 <td class="left"><tt>i32 (i32 *) *</tt></td>
1484 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1485 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1486 <tt>i32</tt>.</td>
1487 </tr>
1488 <tr class="layout">
1489 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1490 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1491 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1492 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1493</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1494</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1495
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1496<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1497<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1498<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1499
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1500<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1501
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1502<p>A vector type is a simple derived type that represents a vector
1503of elements. Vector types are used when multiple primitive data
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1504are operated in parallel using a single instruction (SIMD).
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1505A vector type requires a size (number of
Chris Lattnerb8d172f2005-11-10 01:44:22 +0000[diff] [blame]1506elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1507of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1508considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1509
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1510<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1511
1512<pre>
1513 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1514</pre>
1515
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1516<p>The number of elements is a constant integer value; elementtype may
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1517be any integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1518
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1519<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1520
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1521<table class="layout">
1522 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1523 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1524 <td class="left">Vector of 4 32-bit integer values.</td>
1525 </tr>
1526 <tr class="layout">
1527 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1528 <td class="left">Vector of 8 32-bit floating-point values.</td>
1529 </tr>
1530 <tr class="layout">
1531 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1532 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1533 </tr>
1534</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1535</div>
1536
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1537<!-- _______________________________________________________________________ -->
1538<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1539<div class="doc_text">
1540
1541<h5>Overview:</h5>
1542
1543<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksen8ac04ff2007-10-14 00:34:53 +0000[diff] [blame]1544corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1545In LLVM, opaque types can eventually be resolved to any type (not just a
1546structure type).</p>
1547
1548<h5>Syntax:</h5>
1549
1550<pre>
1551 opaque
1552</pre>
1553
1554<h5>Examples:</h5>
1555
1556<table class="layout">
1557 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1558 <td class="left"><tt>opaque</tt></td>
1559 <td class="left">An opaque type.</td>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1560 </tr>
1561</table>
1562</div>
1563
1564
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1565<!-- *********************************************************************** -->
1566<div class="doc_section"> <a name="constants">Constants</a> </div>
1567<!-- *********************************************************************** -->
1568
1569<div class="doc_text">
1570
1571<p>LLVM has several different basic types of constants. This section describes
1572them all and their syntax.</p>
1573
1574</div>
1575
1576<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1577<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1578
1579<div class="doc_text">
1580
1581<dl>
1582 <dt><b>Boolean constants</b></dt>
1583
1584 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1585 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1586 </dd>
1587
1588 <dt><b>Integer constants</b></dt>
1589
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1590 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1591 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1592 integer types.
1593 </dd>
1594
1595 <dt><b>Floating point constants</b></dt>
1596
1597 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1598 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]1599 notation (see below). The assembler requires the exact decimal value of
1600 a floating-point constant. For example, the assembler accepts 1.25 but
1601 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1602 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1603
1604 <dt><b>Null pointer constants</b></dt>
1605
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1606 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1607 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1608
1609</dl>
1610
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1611<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1612of floating point constants. For example, the form '<tt>double
16130x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
16144.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1615(and the only time that they are generated by the disassembler) is when a
1616floating point constant must be emitted but it cannot be represented as a
1617decimal floating point number. For example, NaN's, infinities, and other
1618special values are represented in their IEEE hexadecimal format so that
1619assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1620
1621</div>
1622
1623<!-- ======================================================================= -->
1624<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1625</div>
1626
1627<div class="doc_text">
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]1628<p>Aggregate constants arise from aggregation of simple constants
1629and smaller aggregate constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1630
1631<dl>
1632 <dt><b>Structure constants</b></dt>
1633
1634 <dd>Structure constants are represented with notation similar to structure
1635 type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner64910ee2007-12-25 20:34:52 +0000[diff] [blame]1636 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1637 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]1638 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1639 types of elements must match those specified by the type.
1640 </dd>
1641
1642 <dt><b>Array constants</b></dt>
1643
1644 <dd>Array constants are represented with notation similar to array type
1645 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1646 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1647 constants must have <a href="#t_array">array type</a>, and the number and
1648 types of elements must match those specified by the type.
1649 </dd>
1650
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1651 <dt><b>Vector constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1652
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1653 <dd>Vector constants are represented with notation similar to vector type
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1654 definitions (a comma separated list of elements, surrounded by
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1655 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]1656 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1657 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1658 match those specified by the type.
1659 </dd>
1660
1661 <dt><b>Zero initialization</b></dt>
1662
1663 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1664 value to zero of <em>any</em> type, including scalar and aggregate types.
1665 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]1666 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1667 initializers.
1668 </dd>
1669</dl>
1670
1671</div>
1672
1673<!-- ======================================================================= -->
1674<div class="doc_subsection">
1675 <a name="globalconstants">Global Variable and Function Addresses</a>
1676</div>
1677
1678<div class="doc_text">
1679
1680<p>The addresses of <a href="#globalvars">global variables</a> and <a
1681href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1682constants. These constants are explicitly referenced when the <a
1683href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1684href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1685file:</p>
1686
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1687<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1688<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]1689@X = global i32 17
1690@Y = global i32 42
1691@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1692</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1693</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1694
1695</div>
1696
1697<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1698<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1699<div class="doc_text">
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1700 <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]1701 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1702 a constant is permitted.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1703
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1704 <p>Undefined values indicate to the compiler that the program is well defined
1705 no matter what value is used, giving the compiler more freedom to optimize.
1706 </p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1707</div>
1708
1709<!-- ======================================================================= -->
1710<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1711</div>
1712
1713<div class="doc_text">
1714
1715<p>Constant expressions are used to allow expressions involving other constants
1716to be used as constants. Constant expressions may be of any <a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1717href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1718that does not have side effects (e.g. load and call are not supported). The
1719following is the syntax for constant expressions:</p>
1720
1721<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1722 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1723 <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]1724 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1725
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1726 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1727 <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]1728 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]1729
1730 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1731 <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]1732 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]1733
1734 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1735 <dd>Truncate a floating point constant to another floating point type. The
1736 size of CST must be larger than the size of TYPE. Both types must be
1737 floating point.</dd>
1738
1739 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1740 <dd>Floating point extend a constant to another type. The size of CST must be
1741 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1742
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]1743 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1744 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1745 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1746 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1747 of the same number of elements. If the value won't fit in the integer type,
1748 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1749
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1750 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1751 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1752 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1753 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1754 of the same number of elements. If the value won't fit in the integer type,
1755 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1756
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1757 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1758 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1759 constant. TYPE must be a scalar or vector floating point type. CST must be of
1760 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1761 of the same number of elements. If the value won't fit in the floating point
1762 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1763
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1764 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1765 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1766 constant. TYPE must be a scalar or vector floating point type. CST must be of
1767 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1768 of the same number of elements. If the value won't fit in the floating point
1769 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1770
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1771 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1772 <dd>Convert a pointer typed constant to the corresponding integer constant
1773 TYPE must be an integer type. CST must be of pointer type. The CST value is
1774 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1775
1776 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1777 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1778 pointer type. CST must be of integer type. The CST value is zero extended,
1779 truncated, or unchanged to make it fit in a pointer size. This one is
1780 <i>really</i> dangerous!</dd>
1781
1782 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1783 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1784 identical (same number of bits). The conversion is done as if the CST value
1785 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]1786 with this operator, just the type. This can be used for conversion of
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1787 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]1788 pointers it is only valid to cast to another pointer type. It is not valid
1789 to bitcast to or from an aggregate type.
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1790 </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1791
1792 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1793
1794 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1795 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1796 instruction, the index list may have zero or more indexes, which are required
1797 to make sense for the type of "CSTPTR".</dd>
1798
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1799 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1800
1801 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1802 constants.</dd>
1803
1804 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1805 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1806
1807 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1808 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1809
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]1810 <dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
1811 <dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
1812
1813 <dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
1814 <dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
1815
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1816 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1817
1818 <dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1819 operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1820
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1821 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1822
1823 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1824 operation</a> on constants.</dd>
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1825
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1826
1827 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1828
1829 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1830 operation</a> on constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1831
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1832 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1833
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1834 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1835 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1836 binary</a> operations. The constraints on operands are the same as those for
1837 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1838 values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1839</dl>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1840</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]1841
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1842<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1843<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1844<!-- *********************************************************************** -->
1845
1846<!-- ======================================================================= -->
1847<div class="doc_subsection">
1848<a name="inlineasm">Inline Assembler Expressions</a>
1849</div>
1850
1851<div class="doc_text">
1852
1853<p>
1854LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1855Module-Level Inline Assembly</a>) through the use of a special value. This
1856value represents the inline assembler as a string (containing the instructions
1857to emit), a list of operand constraints (stored as a string), and a flag that
1858indicates whether or not the inline asm expression has side effects. An example
1859inline assembler expression is:
1860</p>
1861
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1862<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1863<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1864i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1865</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1866</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1867
1868<p>
1869Inline assembler expressions may <b>only</b> be used as the callee operand of
1870a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
1871</p>
1872
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1873<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1874<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1875%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]1876</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1877</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1878
1879<p>
1880Inline asms with side effects not visible in the constraint list must be marked
1881as having side effects. This is done through the use of the
1882'<tt>sideeffect</tt>' keyword, like so:
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]1887call void asm sideeffect "eieio", ""()
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>TODO: The format of the asm and constraints string still need to be
1892documented here. Constraints on what can be done (e.g. duplication, moving, etc
Chris Lattner4f993352008-10-04 18:36:02 +0000[diff] [blame]1893need to be documented). This is probably best done by reference to another
1894document that covers inline asm from a holistic perspective.
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1895</p>
1896
1897</div>
1898
1899<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1900<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
1901<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1902
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1903<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1904
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1905<p>The LLVM instruction set consists of several different
1906classifications of instructions: <a href="#terminators">terminator
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1907instructions</a>, <a href="#binaryops">binary instructions</a>,
1908<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1909 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
1910instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1911
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1912</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1913
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1914<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1915<div class="doc_subsection"> <a name="terminators">Terminator
1916Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1917
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1918<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1919
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1920<p>As mentioned <a href="#functionstructure">previously</a>, every
1921basic block in a program ends with a "Terminator" instruction, which
1922indicates which block should be executed after the current block is
1923finished. These terminator instructions typically yield a '<tt>void</tt>'
1924value: they produce control flow, not values (the one exception being
1925the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1926<p>There are six different terminator instructions: the '<a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1927 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
1928instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1929the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
1930 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
1931 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1932
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1933</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1934
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1935<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1936<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
1937Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1938<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1939<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]1940<pre>
1941 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]1942 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1943</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1944
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1945<h5>Overview:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1946
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]1947<p>The '<tt>ret</tt>' instruction is used to return control flow (and
1948optionally a value) from a function back to the caller.</p>
John Criswell4457dc92004-04-09 16:48:45 +0000[diff] [blame]1949<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]1950returns a value and then causes control flow, and one that just causes
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1951control flow to occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1952
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1953<h5>Arguments:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1954
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]1955<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
1956the return value. The type of the return value must be a
1957'<a href="#t_firstclass">first class</a>' type.</p>
1958
1959<p>A function is not <a href="#wellformed">well formed</a> if
1960it it has a non-void return type and contains a '<tt>ret</tt>'
1961instruction with no return value or a return value with a type that
1962does not match its type, or if it has a void return type and contains
1963a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1964
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1965<h5>Semantics:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1966
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1967<p>When the '<tt>ret</tt>' instruction is executed, control flow
1968returns back to the calling function's context. If the caller is a "<a
John Criswellfa081872004-06-25 15:16:57 +0000[diff] [blame]1969 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1970the instruction after the call. If the caller was an "<a
1971 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1972at the beginning of the "normal" destination block. If the instruction
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1973returns a value, that value shall set the call or invoke instruction's
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1974return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1975
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1976<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1977
1978<pre>
1979 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1980 ret void <i>; Return from a void function</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]1981 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]1982</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1983</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1984<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1985<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1986<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1987<h5>Syntax:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1988<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]1989</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1990<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1991<p>The '<tt>br</tt>' instruction is used to cause control flow to
1992transfer to a different basic block in the current function. There are
1993two forms of this instruction, corresponding to a conditional branch
1994and an unconditional branch.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1995<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1996<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1997single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1998unconditional form of the '<tt>br</tt>' instruction takes a single
1999'<tt>label</tt>' value as a target.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2000<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2001<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2002argument is evaluated. If the value is <tt>true</tt>, control flows
2003to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2004control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2005<h5>Example:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2006<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]2007 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]2008</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2009<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2010<div class="doc_subsubsection">
2011 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2012</div>
2013
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2014<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2015<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2016
2017<pre>
2018 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2019</pre>
2020
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2021<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2022
2023<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
2024several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2025instruction, allowing a branch to occur to one of many possible
2026destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2027
2028
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2029<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2030
2031<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
2032comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
2033an array of pairs of comparison value constants and '<tt>label</tt>'s. The
2034table is not allowed to contain duplicate constant entries.</p>
2035
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2036<h5>Semantics:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2037
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2038<p>The <tt>switch</tt> instruction specifies a table of values and
2039destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]2040table is searched for the given value. If the value is found, control flow is
2041transfered to the corresponding destination; otherwise, control flow is
2042transfered to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2043
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2044<h5>Implementation:</h5>
2045
2046<p>Depending on properties of the target machine and the particular
2047<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]2048ways. For example, it could be generated as a series of chained conditional
2049branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2050
2051<h5>Example:</h5>
2052
2053<pre>
2054 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2055 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2056 switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2057
2058 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2059 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2060
2061 <i>; Implement a jump table:</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2062 switch i32 %val, label %otherwise [ i32 0, label %onzero
2063 i32 1, label %onone
2064 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2065</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2066</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2067
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2068<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2069<div class="doc_subsubsection">
2070 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2071</div>
2072
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2073<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2074
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2075<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2076
2077<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2078 &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]2079 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2080</pre>
2081
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2082<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2083
2084<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
2085function, with the possibility of control flow transfer to either the
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2086'<tt>normal</tt>' label or the
2087'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2088"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
2089"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2090href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]2091continued at the dynamically nearest "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2092
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2093<h5>Arguments:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2094
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2095<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2096
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2097<ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2098 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]2099 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2100 convention</a> the call should use. If none is specified, the call defaults
2101 to using C calling conventions.
2102 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2103
2104 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
2105 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
2106 and '<tt>inreg</tt>' attributes are valid here.</li>
2107
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2108 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
2109 function value being invoked. In most cases, this is a direct function
2110 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
2111 an arbitrary pointer to function value.
2112 </li>
2113
2114 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
2115 function to be invoked. </li>
2116
2117 <li>'<tt>function args</tt>': argument list whose types match the function
2118 signature argument types. If the function signature indicates the function
2119 accepts a variable number of arguments, the extra arguments can be
2120 specified. </li>
2121
2122 <li>'<tt>normal label</tt>': the label reached when the called function
2123 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
2124
2125 <li>'<tt>exception label</tt>': the label reached when a callee returns with
2126 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
2127
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2128 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2129 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2130 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2131</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2132
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2133<h5>Semantics:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2134
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2135<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2136href="#i_call">call</a></tt>' instruction in most regards. The primary
2137difference is that it establishes an association with a label, which is used by
2138the runtime library to unwind the stack.</p>
2139
2140<p>This instruction is used in languages with destructors to ensure that proper
2141cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2142exception. Additionally, this is important for implementation of
2143'<tt>catch</tt>' clauses in high-level languages that support them.</p>
2144
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2145<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2146<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2147 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2148 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2149 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2150 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2151</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2152</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2153
2154
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2155<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2156
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2157<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2158Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2159
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2160<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2161
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2162<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2163<pre>
2164 unwind
2165</pre>
2166
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2167<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2168
2169<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
2170at the first callee in the dynamic call stack which used an <a
2171href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
2172primarily used to implement exception handling.</p>
2173
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2174<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2175
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]2176<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2177immediately halt. The dynamic call stack is then searched for the first <a
2178href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
2179execution continues at the "exceptional" destination block specified by the
2180<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
2181dynamic call chain, undefined behavior results.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2182</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2183
2184<!-- _______________________________________________________________________ -->
2185
2186<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2187Instruction</a> </div>
2188
2189<div class="doc_text">
2190
2191<h5>Syntax:</h5>
2192<pre>
2193 unreachable
2194</pre>
2195
2196<h5>Overview:</h5>
2197
2198<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
2199instruction is used to inform the optimizer that a particular portion of the
2200code is not reachable. This can be used to indicate that the code after a
2201no-return function cannot be reached, and other facts.</p>
2202
2203<h5>Semantics:</h5>
2204
2205<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
2206</div>
2207
2208
2209
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2210<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2211<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2212<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2213<p>Binary operators are used to do most of the computation in a
Chris Lattner5a158142008-04-01 18:47:32 +0000[diff] [blame]2214program. They require two operands of the same type, execute an operation on them, and
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2215produce a single value. The operands might represent
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2216multiple 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]2217The result value has the same type as its operands.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2218<p>There are several different binary operators:</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2219</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2220<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2221<div class="doc_subsubsection">
2222 <a name="i_add">'<tt>add</tt>' Instruction</a>
2223</div>
2224
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2225<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2226
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2227<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2228
2229<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2230 &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]2231</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2232
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2233<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2234
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2235<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2236
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2237<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2238
2239<p>The two arguments to the '<tt>add</tt>' instruction must be <a
2240 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
2241 <a href="#t_vector">vector</a> values. Both arguments must have identical
2242 types.</p>
2243
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2244<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2245
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2246<p>The value produced is the integer or floating point sum of the two
2247operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2248
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2249<p>If an integer sum has unsigned overflow, the result returned is the
2250mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2251the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2252
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2253<p>Because LLVM integers use a two's complement representation, this
2254instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2255
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2256<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2257
2258<pre>
2259 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2260</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2261</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2262<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2263<div class="doc_subsubsection">
2264 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2265</div>
2266
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2267<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2268
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2269<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2270
2271<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2272 &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]2273</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2274
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2275<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2276
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2277<p>The '<tt>sub</tt>' instruction returns the difference of its two
2278operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2279
2280<p>Note that the '<tt>sub</tt>' instruction is used to represent the
2281'<tt>neg</tt>' instruction present in most other intermediate
2282representations.</p>
2283
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2284<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2285
2286<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
2287 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2288 or <a href="#t_vector">vector</a> values. Both arguments must have identical
2289 types.</p>
2290
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2291<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2292
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2293<p>The value produced is the integer or floating point difference of
2294the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2295
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2296<p>If an integer difference has unsigned overflow, the result returned is the
2297mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2298the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2299
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2300<p>Because LLVM integers use a two's complement representation, this
2301instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2302
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2303<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2304<pre>
2305 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2306 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2307</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2308</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2309
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2310<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2311<div class="doc_subsubsection">
2312 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2313</div>
2314
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2315<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2316
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2317<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2318<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]2319</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2320<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2321<p>The '<tt>mul</tt>' instruction returns the product of its two
2322operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2323
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2324<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2325
2326<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
2327href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2328or <a href="#t_vector">vector</a> values. Both arguments must have identical
2329types.</p>
2330
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2331<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2332
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2333<p>The value produced is the integer or floating point product of the
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2334two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2335
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2336<p>If the result of an integer multiplication has unsigned overflow,
2337the result returned is the mathematical result modulo
23382<sup>n</sup>, where n is the bit width of the result.</p>
2339<p>Because LLVM integers use a two's complement representation, and the
2340result is the same width as the operands, this instruction returns the
2341correct result for both signed and unsigned integers. If a full product
2342(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
2343should be sign-extended or zero-extended as appropriate to the
2344width of the full product.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2345<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2346<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]2347</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2348</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2349
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2350<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2351<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2352</a></div>
2353<div class="doc_text">
2354<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2355<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]2356</pre>
2357<h5>Overview:</h5>
2358<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2359operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2360
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2361<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2362
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2363<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2364<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2365values. Both arguments must have identical types.</p>
2366
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2367<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2368
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2369<p>The value produced is the unsigned integer quotient of the two operands.</p>
2370<p>Note that unsigned integer division and signed integer division are distinct
2371operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2372<p>Division by zero leads to undefined behavior.</p>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2373<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2374<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]2375</pre>
2376</div>
2377<!-- _______________________________________________________________________ -->
2378<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2379</a> </div>
2380<div class="doc_text">
2381<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2382<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2383 &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]2384</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2385
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2386<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2387
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2388<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2389operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2390
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2391<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2392
2393<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2394<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2395values. Both arguments must have identical types.</p>
2396
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2397<h5>Semantics:</h5>
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2398<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]2399<p>Note that signed integer division and unsigned integer division are distinct
2400operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2401<p>Division by zero leads to undefined behavior. Overflow also leads to
2402undefined behavior; this is a rare case, but can occur, for example,
2403by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2404<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2405<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]2406</pre>
2407</div>
2408<!-- _______________________________________________________________________ -->
2409<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2410Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2411<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2412<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2413<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2414 &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]2415</pre>
2416<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2417
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2418<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2419operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2420
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2421<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2422
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2423<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2424<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2425of floating point values. Both arguments must have identical types.</p>
2426
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2427<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2428
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2429<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2430
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2431<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2432
2433<pre>
2434 &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]2435</pre>
2436</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2437
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2438<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2439<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2440</div>
2441<div class="doc_text">
2442<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2443<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]2444</pre>
2445<h5>Overview:</h5>
2446<p>The '<tt>urem</tt>' instruction returns the remainder from the
2447unsigned division of its two arguments.</p>
2448<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2449<p>The two arguments to the '<tt>urem</tt>' instruction must be
2450<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2451values. Both arguments must have identical types.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2452<h5>Semantics:</h5>
2453<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2454This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2455<p>Note that unsigned integer remainder and signed integer remainder are
2456distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
2457<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2458<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2459<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]2460</pre>
2461
2462</div>
2463<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2464<div class="doc_subsubsection">
2465 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
2466</div>
2467
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2468<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2469
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2470<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2471
2472<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2473 &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]2474</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2475
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2476<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2477
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2478<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2479signed division of its two operands. This instruction can also take
2480<a href="#t_vector">vector</a> versions of the values in which case
2481the elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]2482
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2483<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2484
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2485<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2486<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2487values. Both arguments must have identical types.</p>
2488
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2489<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2490
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2491<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2492has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
2493operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2494a value. For more information about the difference, see <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2495 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2496Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencer64f5c6c2007-03-24 22:40:44 +0000[diff] [blame]2497please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2498Wikipedia: modulo operation</a>.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2499<p>Note that signed integer remainder and unsigned integer remainder are
2500distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
2501<p>Taking the remainder of a division by zero leads to undefined behavior.
2502Overflow also leads to undefined behavior; this is a rare case, but can occur,
2503for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
2504(The remainder doesn't actually overflow, but this rule lets srem be
2505implemented using instructions that return both the result of the division
2506and the remainder.)</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2507<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2508<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]2509</pre>
2510
2511</div>
2512<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2513<div class="doc_subsubsection">
2514 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
2515
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2516<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2517
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2518<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2519<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]2520</pre>
2521<h5>Overview:</h5>
2522<p>The '<tt>frem</tt>' instruction returns the remainder from the
2523division of its two operands.</p>
2524<h5>Arguments:</h5>
2525<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2526<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2527of floating point values. Both arguments must have identical types.</p>
2528
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2529<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2530
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2531<p>This instruction returns the <i>remainder</i> of a division.
2532The remainder has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2533
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2534<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2535
2536<pre>
2537 &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]2538</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2539</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]2540
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2541<!-- ======================================================================= -->
2542<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2543Operations</a> </div>
2544<div class="doc_text">
2545<p>Bitwise binary operators are used to do various forms of
2546bit-twiddling in a program. They are generally very efficient
2547instructions and can commonly be strength reduced from other
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2548instructions. They require two operands of the same type, execute an operation on them,
2549and 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]2550</div>
2551
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2552<!-- _______________________________________________________________________ -->
2553<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2554Instruction</a> </div>
2555<div class="doc_text">
2556<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2557<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]2558</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2559
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2560<h5>Overview:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2561
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2562<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2563the left a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2564
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2565<h5>Arguments:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2566
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2567<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2568 href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2569type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2570
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2571<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2572
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2573<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
2574where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
2575equal 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]2576
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2577<h5>Example:</h5><pre>
2578 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2579 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2580 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2581 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2582</pre>
2583</div>
2584<!-- _______________________________________________________________________ -->
2585<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2586Instruction</a> </div>
2587<div class="doc_text">
2588<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2589<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]2590</pre>
2591
2592<h5>Overview:</h5>
2593<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2594operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2595
2596<h5>Arguments:</h5>
2597<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2598<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]2599type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2600
2601<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2602
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2603<p>This instruction always performs a logical shift right operation. The most
2604significant bits of the result will be filled with zero bits after the
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2605shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
2606the number of bits in <tt>op1</tt>, the result is undefined.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2607
2608<h5>Example:</h5>
2609<pre>
2610 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2611 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2612 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2613 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2614 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2615</pre>
2616</div>
2617
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2618<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2619<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2620Instruction</a> </div>
2621<div class="doc_text">
2622
2623<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2624<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]2625</pre>
2626
2627<h5>Overview:</h5>
2628<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2629operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2630
2631<h5>Arguments:</h5>
2632<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2633<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]2634type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2635
2636<h5>Semantics:</h5>
2637<p>This instruction always performs an arithmetic shift right operation,
2638The most significant bits of the result will be filled with the sign bit
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2639of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
2640larger than the number of bits in <tt>op1</tt>, the result is undefined.
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2641</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2642
2643<h5>Example:</h5>
2644<pre>
2645 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2646 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2647 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2648 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2649 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2650</pre>
2651</div>
2652
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2653<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2654<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2655Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2656
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2657<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2658
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2659<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2660
2661<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2662 &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]2663</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2664
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2665<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2666
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2667<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2668its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2669
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2670<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2671
2672<p>The two arguments to the '<tt>and</tt>' instruction must be
2673<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2674values. Both arguments must have identical types.</p>
2675
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2676<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2677<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2678<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2679<div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2680<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2681 <tbody>
2682 <tr>
2683 <td>In0</td>
2684 <td>In1</td>
2685 <td>Out</td>
2686 </tr>
2687 <tr>
2688 <td>0</td>
2689 <td>0</td>
2690 <td>0</td>
2691 </tr>
2692 <tr>
2693 <td>0</td>
2694 <td>1</td>
2695 <td>0</td>
2696 </tr>
2697 <tr>
2698 <td>1</td>
2699 <td>0</td>
2700 <td>0</td>
2701 </tr>
2702 <tr>
2703 <td>1</td>
2704 <td>1</td>
2705 <td>1</td>
2706 </tr>
2707 </tbody>
2708</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2709</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2710<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2711<pre>
2712 &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]2713 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2714 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2715</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2716</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2717<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2718<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2719<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2720<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2721<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]2722</pre>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2723<h5>Overview:</h5>
2724<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2725or of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2726<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2727
2728<p>The two arguments to the '<tt>or</tt>' instruction must be
2729<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2730values. Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2731<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2732<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2733<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2734<div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2735<table border="1" cellspacing="0" cellpadding="4">
2736 <tbody>
2737 <tr>
2738 <td>In0</td>
2739 <td>In1</td>
2740 <td>Out</td>
2741 </tr>
2742 <tr>
2743 <td>0</td>
2744 <td>0</td>
2745 <td>0</td>
2746 </tr>
2747 <tr>
2748 <td>0</td>
2749 <td>1</td>
2750 <td>1</td>
2751 </tr>
2752 <tr>
2753 <td>1</td>
2754 <td>0</td>
2755 <td>1</td>
2756 </tr>
2757 <tr>
2758 <td>1</td>
2759 <td>1</td>
2760 <td>1</td>
2761 </tr>
2762 </tbody>
2763</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2764</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2765<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2766<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2767 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2768 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2769</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2770</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2771<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2772<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2773Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2774<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2775<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2776<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]2777</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2778<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2779<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2780or of its two operands. The <tt>xor</tt> is used to implement the
2781"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2782<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2783<p>The two arguments to the '<tt>xor</tt>' instruction must be
2784<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2785values. Both arguments must have identical types.</p>
2786
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2787<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2788
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2789<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2790<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2791<div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2792<table border="1" cellspacing="0" cellpadding="4">
2793 <tbody>
2794 <tr>
2795 <td>In0</td>
2796 <td>In1</td>
2797 <td>Out</td>
2798 </tr>
2799 <tr>
2800 <td>0</td>
2801 <td>0</td>
2802 <td>0</td>
2803 </tr>
2804 <tr>
2805 <td>0</td>
2806 <td>1</td>
2807 <td>1</td>
2808 </tr>
2809 <tr>
2810 <td>1</td>
2811 <td>0</td>
2812 <td>1</td>
2813 </tr>
2814 <tr>
2815 <td>1</td>
2816 <td>1</td>
2817 <td>0</td>
2818 </tr>
2819 </tbody>
2820</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2821</div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2822<p> </p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2823<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2824<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2825 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2826 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2827 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2828</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2829</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2830
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2831<!-- ======================================================================= -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2832<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2833 <a name="vectorops">Vector Operations</a>
2834</div>
2835
2836<div class="doc_text">
2837
2838<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2839target-independent manner. These instructions cover the element-access and
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2840vector-specific operations needed to process vectors effectively. While LLVM
2841does directly support these vector operations, many sophisticated algorithms
2842will want to use target-specific intrinsics to take full advantage of a specific
2843target.</p>
2844
2845</div>
2846
2847<!-- _______________________________________________________________________ -->
2848<div class="doc_subsubsection">
2849 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
2850</div>
2851
2852<div class="doc_text">
2853
2854<h5>Syntax:</h5>
2855
2856<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2857 &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]2858</pre>
2859
2860<h5>Overview:</h5>
2861
2862<p>
2863The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2864element from a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2865</p>
2866
2867
2868<h5>Arguments:</h5>
2869
2870<p>
2871The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2872value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2873an index indicating the position from which to extract the element.
2874The index may be a variable.</p>
2875
2876<h5>Semantics:</h5>
2877
2878<p>
2879The result is a scalar of the same type as the element type of
2880<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
2881<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
2882results are undefined.
2883</p>
2884
2885<h5>Example:</h5>
2886
2887<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2888 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2889</pre>
2890</div>
2891
2892
2893<!-- _______________________________________________________________________ -->
2894<div class="doc_subsubsection">
2895 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
2896</div>
2897
2898<div class="doc_text">
2899
2900<h5>Syntax:</h5>
2901
2902<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]2903 &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]2904</pre>
2905
2906<h5>Overview:</h5>
2907
2908<p>
2909The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2910element into a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2911</p>
2912
2913
2914<h5>Arguments:</h5>
2915
2916<p>
2917The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2918value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2919scalar value whose type must equal the element type of the first
2920operand. The third operand is an index indicating the position at
2921which to insert the value. The index may be a variable.</p>
2922
2923<h5>Semantics:</h5>
2924
2925<p>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2926The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2927element values are those of <tt>val</tt> except at position
2928<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
2929exceeds the length of <tt>val</tt>, the results are undefined.
2930</p>
2931
2932<h5>Example:</h5>
2933
2934<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2935 %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]2936</pre>
2937</div>
2938
2939<!-- _______________________________________________________________________ -->
2940<div class="doc_subsubsection">
2941 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
2942</div>
2943
2944<div class="doc_text">
2945
2946<h5>Syntax:</h5>
2947
2948<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]2949 &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]2950</pre>
2951
2952<h5>Overview:</h5>
2953
2954<p>
2955The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]2956from two input vectors, returning a vector with the same element type as
2957the input and length that is the same as the shuffle mask.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2958</p>
2959
2960<h5>Arguments:</h5>
2961
2962<p>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]2963The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
2964with types that match each other. The third argument is a shuffle mask whose
2965element type is always 'i32'. The result of the instruction is a vector whose
2966length is the same as the shuffle mask and whose element type is the same as
2967the element type of the first two operands.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2968</p>
2969
2970<p>
2971The shuffle mask operand is required to be a constant vector with either
2972constant integer or undef values.
2973</p>
2974
2975<h5>Semantics:</h5>
2976
2977<p>
2978The elements of the two input vectors are numbered from left to right across
2979both of the vectors. The shuffle mask operand specifies, for each element of
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]2980the result vector, which element of the two input vectors the result element
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2981gets. The element selector may be undef (meaning "don't care") and the second
2982operand may be undef if performing a shuffle from only one vector.
2983</p>
2984
2985<h5>Example:</h5>
2986
2987<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2988 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2989 &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]2990 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
2991 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i> - Identity shuffle.
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]2992 %result = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
2993 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
2994 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
2995 &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]2996</pre>
2997</div>
2998
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]2999
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3000<!-- ======================================================================= -->
3001<div class="doc_subsection">
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3002 <a name="aggregateops">Aggregate Operations</a>
3003</div>
3004
3005<div class="doc_text">
3006
3007<p>LLVM supports several instructions for working with aggregate values.
3008</p>
3009
3010</div>
3011
3012<!-- _______________________________________________________________________ -->
3013<div class="doc_subsubsection">
3014 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3015</div>
3016
3017<div class="doc_text">
3018
3019<h5>Syntax:</h5>
3020
3021<pre>
3022 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3023</pre>
3024
3025<h5>Overview:</h5>
3026
3027<p>
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3028The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3029or array element from an aggregate value.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3030</p>
3031
3032
3033<h5>Arguments:</h5>
3034
3035<p>
3036The first operand of an '<tt>extractvalue</tt>' instruction is a
3037value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3038type. The operands are constant indices to specify which value to extract
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3039in a similar manner as indices in a
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3040'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3041</p>
3042
3043<h5>Semantics:</h5>
3044
3045<p>
3046The result is the value at the position in the aggregate specified by
3047the index operands.
3048</p>
3049
3050<h5>Example:</h5>
3051
3052<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3053 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3054</pre>
3055</div>
3056
3057
3058<!-- _______________________________________________________________________ -->
3059<div class="doc_subsubsection">
3060 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3061</div>
3062
3063<div class="doc_text">
3064
3065<h5>Syntax:</h5>
3066
3067<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3068 &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]3069</pre>
3070
3071<h5>Overview:</h5>
3072
3073<p>
3074The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3075into a struct field or array element in an aggregate.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3076</p>
3077
3078
3079<h5>Arguments:</h5>
3080
3081<p>
3082The first operand of an '<tt>insertvalue</tt>' instruction is a
3083value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
3084The second operand is a first-class value to insert.
Dan Gohmanc4b49eb2008-05-23 21:53:15 +0000[diff] [blame]3085The following operands are constant indices
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3086indicating the position at which to insert the value in a similar manner as
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3087indices in a
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3088'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3089The value to insert must have the same type as the value identified
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3090by the indices.
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3091</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3092
3093<h5>Semantics:</h5>
3094
3095<p>
3096The result is an aggregate of the same type as <tt>val</tt>. Its
3097value is that of <tt>val</tt> except that the value at the position
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3098specified by the indices is that of <tt>elt</tt>.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3099</p>
3100
3101<h5>Example:</h5>
3102
3103<pre>
Dan Gohman52bb2db2008-06-23 15:26:37 +0000[diff] [blame]3104 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3105</pre>
3106</div>
3107
3108
3109<!-- ======================================================================= -->
3110<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3111 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3112</div>
3113
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3114<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3115
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3116<p>A key design point of an SSA-based representation is how it
3117represents memory. In LLVM, no memory locations are in SSA form, which
3118makes things very simple. This section describes how to read, write,
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3119allocate, and free memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3120
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3121</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3122
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3123<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3124<div class="doc_subsubsection">
3125 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3126</div>
3127
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3128<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3129
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3130<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3131
3132<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3133 &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]3134</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3135
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3136<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3137
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3138<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]3139heap and returns a pointer to it. The object is always allocated in the generic
3140address space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3141
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3142<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3143
3144<p>The '<tt>malloc</tt>' instruction allocates
3145<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswell6e4ca612004-02-24 16:13:56 +0000[diff] [blame]3146bytes of memory from the operating system and returns a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3147appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3148number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3149If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3150be aligned to at least that boundary. If not specified, or if zero, the target can
3151choose to align the allocation on any convenient boundary.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3152
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3153<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3154
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3155<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3156
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3157<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3158a pointer is returned. The result of a zero byte allocattion is undefined. The
3159result is null if there is insufficient memory available.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3160
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3161<h5>Example:</h5>
3162
3163<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3164 %array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3165
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3166 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3167 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3168 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3169 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3170 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3171</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3172</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3173
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3174<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3175<div class="doc_subsubsection">
3176 <a name="i_free">'<tt>free</tt>' Instruction</a>
3177</div>
3178
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3179<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3180
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3181<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3182
3183<pre>
3184 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3185</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3186
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3187<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3188
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3189<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]3190memory heap to be reallocated in the future.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3191
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3192<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3193
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3194<p>'<tt>value</tt>' shall be a pointer value that points to a value
3195that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
3196instruction.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3197
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3198<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3199
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3200<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattnere0db56d2008-04-19 22:41:32 +0000[diff] [blame]3201after this instruction executes. If the pointer is null, the operation
3202is a noop.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3203
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3204<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3205
3206<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3207 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
3208 free [4 x i8]* %array
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3209</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3210</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3211
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3212<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3213<div class="doc_subsubsection">
3214 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3215</div>
3216
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3217<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3218
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3219<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3220
3221<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3222 &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]3223</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3224
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3225<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3226
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3227<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
3228currently executing function, to be automatically released when this function
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]3229returns to its caller. The object is always allocated in the generic address
3230space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3231
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3232<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3233
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3234<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3235bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3236appropriate type to the program. If "NumElements" is specified, it is the
3237number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3238If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3239to be aligned to at least that boundary. If not specified, or if zero, the target
3240can choose to align the allocation on any convenient boundary.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3241
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3242<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3243
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3244<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3245
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3246<p>Memory is allocated; a pointer is returned. The operation is undefiend if
3247there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3248memory is automatically released when the function returns. The '<tt>alloca</tt>'
3249instruction is commonly used to represent automatic variables that must
3250have an address available. When the function returns (either with the <tt><a
John Criswelldae2e932005-05-12 16:55:34 +0000[diff] [blame]3251 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]3252instructions), the memory is reclaimed. Allocating zero bytes
3253is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3254
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3255<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3256
3257<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3258 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3259 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3260 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3261 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3262</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3263</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3264
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3265<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3266<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3267Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3268<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3269<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]3270<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]3271<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3272<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3273<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3274<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]3275address from which to load. The pointer must point to a <a
Chris Lattnere53e5082004-06-03 22:57:15 +0000[diff] [blame]3276 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]3277marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3278the number or order of execution of this <tt>load</tt> with other
3279volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3280instructions. </p>
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3281<p>
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3282The optional constant "align" argument specifies the alignment of the operation
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3283(that is, the alignment of the memory address). A value of 0 or an
3284omitted "align" argument means that the operation has the preferential
3285alignment for the target. It is the responsibility of the code emitter
3286to ensure that the alignment information is correct. Overestimating
3287the alignment results in an undefined behavior. Underestimating the
3288alignment may produce less efficient code. An alignment of 1 is always
3289safe.
3290</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3291<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3292<p>The location of memory pointed to is loaded.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3293<h5>Examples:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3294<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3295 <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3296 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
3297 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3298</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3299</div>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3300<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3301<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3302Instruction</a> </div>
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]3303<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3304<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]3305<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
3306 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]3307</pre>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3308<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3309<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3310<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3311<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3312to 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]3313operand must be a pointer to the <a href="#t_firstclass">first class</a> type
3314of the '<tt>&lt;value&gt;</tt>'
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]3315operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3316optimizer is not allowed to modify the number or order of execution of
3317this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
3318 href="#i_store">store</a></tt> instructions.</p>
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3319<p>
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3320The optional constant "align" argument specifies the alignment of the operation
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3321(that is, the alignment of the memory address). A value of 0 or an
3322omitted "align" argument means that the operation has the preferential
3323alignment for the target. It is the responsibility of the code emitter
3324to ensure that the alignment information is correct. Overestimating
3325the alignment results in an undefined behavior. Underestimating the
3326alignment may produce less efficient code. An alignment of 1 is always
3327safe.
3328</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3329<h5>Semantics:</h5>
3330<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
3331at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3332<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3333<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]3334 store i32 3, i32* %ptr <i>; yields {void}</i>
3335 %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]3336</pre>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3337</div>
3338
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3339<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3340<div class="doc_subsubsection">
3341 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3342</div>
3343
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3344<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3345<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3346<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3347 &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]3348</pre>
3349
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3350<h5>Overview:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3351
3352<p>
3353The '<tt>getelementptr</tt>' instruction is used to get the address of a
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3354subelement of an aggregate data structure. It performs address calculation only
3355and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3356
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3357<h5>Arguments:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3358
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3359<p>The first argument is always a pointer, and forms the basis of the
3360calculation. The remaining arguments are indices, that indicate which of the
3361elements of the aggregate object are indexed. The interpretation of each index
3362is dependent on the type being indexed into. The first index always indexes the
3363pointer value given as the first argument, the second index indexes a value of
3364the type pointed to (not necessarily the value directly pointed to, since the
3365first index can be non-zero), etc. The first type indexed into must be a pointer
3366value, subsequent types can be arrays, vectors and structs. Note that subsequent
3367types being indexed into can never be pointers, since that would require loading
3368the pointer before continuing calculation.</p>
3369
3370<p>The type of each index argument depends on the type it is indexing into.
3371When indexing into a (packed) structure, only <tt>i32</tt> integer
3372<b>constants</b> are allowed. When indexing into an array, pointer or vector,
3373only integers of 32 or 64 bits are allowed (also non-constants). 32-bit values
3374will be sign extended to 64-bits if required.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3375
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3376<p>For example, let's consider a C code fragment and how it gets
3377compiled to LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3378
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3379<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3380<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3381struct RT {
3382 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3383 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3384 char C;
3385};
3386struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3387 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3388 double Y;
3389 struct RT Z;
3390};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3391
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3392int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3393 return &amp;s[1].Z.B[5][13];
3394}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3395</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3396</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3397
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3398<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3399
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3400<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3401<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3402%RT = type { i8 , [10 x [20 x i32]], i8 }
3403%ST = type { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3404
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3405define i32* %foo(%ST* %s) {
3406entry:
3407 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3408 ret i32* %reg
3409}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3410</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3411</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3412
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3413<h5>Semantics:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3414
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3415<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]3416type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3417}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3418the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3419i8 }</tt>' type, another structure. The third index indexes into the second
3420element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3421array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3422'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
3423to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3424
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3425<p>Note that it is perfectly legal to index partially through a
3426structure, returning a pointer to an inner element. Because of this,
3427the LLVM code for the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3428
3429<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3430 define i32* %foo(%ST* %s) {
3431 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3432 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3433 %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]3434 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3435 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
3436 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3437 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3438</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3439
3440<p>Note that it is undefined to access an array out of bounds: array and
3441pointer indexes must always be within the defined bounds of the array type.
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]3442The one exception for this rule is zero length arrays. These arrays are
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3443defined to be accessible as variable length arrays, which requires access
3444beyond the zero'th element.</p>
3445
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3446<p>The getelementptr instruction is often confusing. For some more insight
3447into how it works, see <a href="GetElementPtr.html">the getelementptr
3448FAQ</a>.</p>
3449
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3450<h5>Example:</h5>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3451
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3452<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3453 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3454 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
3455 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3456 %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]3457 <i>; yields i8*:eptr</i>
3458 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3459</pre>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3460</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3461
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3462<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3463<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3464</div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3465<div class="doc_text">
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3466<p>The instructions in this category are the conversion instructions (casting)
3467which all take a single operand and a type. They perform various bit conversions
3468on the operand.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3469</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3470
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3471<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3472<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3473 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
3474</div>
3475<div class="doc_text">
3476
3477<h5>Syntax:</h5>
3478<pre>
3479 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3480</pre>
3481
3482<h5>Overview:</h5>
3483<p>
3484The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
3485</p>
3486
3487<h5>Arguments:</h5>
3488<p>
3489The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
3490be 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]3491and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3492type. The bit size of <tt>value</tt> must be larger than the bit size of
3493<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3494
3495<h5>Semantics:</h5>
3496<p>
3497The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3498and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
3499larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
3500It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3501
3502<h5>Example:</h5>
3503<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3504 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3505 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
3506 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3507</pre>
3508</div>
3509
3510<!-- _______________________________________________________________________ -->
3511<div class="doc_subsubsection">
3512 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
3513</div>
3514<div class="doc_text">
3515
3516<h5>Syntax:</h5>
3517<pre>
3518 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3519</pre>
3520
3521<h5>Overview:</h5>
3522<p>The '<tt>zext</tt>' instruction zero extends its operand to type
3523<tt>ty2</tt>.</p>
3524
3525
3526<h5>Arguments:</h5>
3527<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]3528<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3529also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3530<tt>value</tt> must be smaller than the bit size of the destination type,
3531<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3532
3533<h5>Semantics:</h5>
3534<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]3535bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3536
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]3537<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]3538
3539<h5>Example:</h5>
3540<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3541 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3542 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3543</pre>
3544</div>
3545
3546<!-- _______________________________________________________________________ -->
3547<div class="doc_subsubsection">
3548 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3549</div>
3550<div class="doc_text">
3551
3552<h5>Syntax:</h5>
3553<pre>
3554 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3555</pre>
3556
3557<h5>Overview:</h5>
3558<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3559
3560<h5>Arguments:</h5>
3561<p>
3562The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3563<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3564also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3565<tt>value</tt> must be smaller than the bit size of the destination type,
3566<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3567
3568<h5>Semantics:</h5>
3569<p>
3570The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3571bit (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]3572the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3573
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3574<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]3575
3576<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3577<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3578 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3579 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3580</pre>
3581</div>
3582
3583<!-- _______________________________________________________________________ -->
3584<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3585 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3586</div>
3587
3588<div class="doc_text">
3589
3590<h5>Syntax:</h5>
3591
3592<pre>
3593 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3594</pre>
3595
3596<h5>Overview:</h5>
3597<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3598<tt>ty2</tt>.</p>
3599
3600
3601<h5>Arguments:</h5>
3602<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3603 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3604cast it to. The size of <tt>value</tt> must be larger than the size of
3605<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3606<i>no-op cast</i>.</p>
3607
3608<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3609<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3610<a href="#t_floating">floating point</a> type to a smaller
3611<a href="#t_floating">floating point</a> type. If the value cannot fit within
3612the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3613
3614<h5>Example:</h5>
3615<pre>
3616 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3617 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3618</pre>
3619</div>
3620
3621<!-- _______________________________________________________________________ -->
3622<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3623 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3624</div>
3625<div class="doc_text">
3626
3627<h5>Syntax:</h5>
3628<pre>
3629 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3630</pre>
3631
3632<h5>Overview:</h5>
3633<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3634floating point value.</p>
3635
3636<h5>Arguments:</h5>
3637<p>The '<tt>fpext</tt>' instruction takes a
3638<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3639and a <a href="#t_floating">floating point</a> type to cast it to. The source
3640type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3641
3642<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3643<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3644<a href="#t_floating">floating point</a> type to a larger
3645<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3646used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3647<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]3648
3649<h5>Example:</h5>
3650<pre>
3651 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3652 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3653</pre>
3654</div>
3655
3656<!-- _______________________________________________________________________ -->
3657<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]3658 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3659</div>
3660<div class="doc_text">
3661
3662<h5>Syntax:</h5>
3663<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3664 &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]3665</pre>
3666
3667<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3668<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3669unsigned integer equivalent of type <tt>ty2</tt>.
3670</p>
3671
3672<h5>Arguments:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3673<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]3674scalar or vector <a href="#t_floating">floating point</a> value, and a type
3675to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3676type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3677vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3678
3679<h5>Semantics:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3680<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3681<a href="#t_floating">floating point</a> operand into the nearest (rounding
3682towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3683the results are undefined.</p>
3684
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3685<h5>Example:</h5>
3686<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3687 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3688 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3689 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3690</pre>
3691</div>
3692
3693<!-- _______________________________________________________________________ -->
3694<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3695 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3696</div>
3697<div class="doc_text">
3698
3699<h5>Syntax:</h5>
3700<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3701 &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]3702</pre>
3703
3704<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3705<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3706<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]3707</p>
3708
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3709<h5>Arguments:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3710<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]3711scalar or vector <a href="#t_floating">floating point</a> value, and a type
3712to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3713type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3714vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3715
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3716<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3717<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3718<a href="#t_floating">floating point</a> operand into the nearest (rounding
3719towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3720the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3721
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3722<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3723<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3724 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3725 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3726 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3727</pre>
3728</div>
3729
3730<!-- _______________________________________________________________________ -->
3731<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3732 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3733</div>
3734<div class="doc_text">
3735
3736<h5>Syntax:</h5>
3737<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3738 &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]3739</pre>
3740
3741<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3742<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3743integer and converts that value to the <tt>ty2</tt> type.</p>
3744
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3745<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3746<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3747scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3748to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3749type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3750floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3751
3752<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3753<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3754integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3755the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3756
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3757<h5>Example:</h5>
3758<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3759 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3760 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3761</pre>
3762</div>
3763
3764<!-- _______________________________________________________________________ -->
3765<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3766 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3767</div>
3768<div class="doc_text">
3769
3770<h5>Syntax:</h5>
3771<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3772 &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]3773</pre>
3774
3775<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3776<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3777integer and converts that value to the <tt>ty2</tt> type.</p>
3778
3779<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3780<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3781scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3782to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3783type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3784floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3785
3786<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3787<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3788integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3789the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3790
3791<h5>Example:</h5>
3792<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3793 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3794 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3795</pre>
3796</div>
3797
3798<!-- _______________________________________________________________________ -->
3799<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3800 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3801</div>
3802<div class="doc_text">
3803
3804<h5>Syntax:</h5>
3805<pre>
3806 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3807</pre>
3808
3809<h5>Overview:</h5>
3810<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3811the integer type <tt>ty2</tt>.</p>
3812
3813<h5>Arguments:</h5>
3814<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3815must 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]3816<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]3817
3818<h5>Semantics:</h5>
3819<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3820<tt>ty2</tt> by interpreting the pointer value as an integer and either
3821truncating or zero extending that value to the size of the integer type. If
3822<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3823<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]3824are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3825change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3826
3827<h5>Example:</h5>
3828<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3829 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3830 %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]3831</pre>
3832</div>
3833
3834<!-- _______________________________________________________________________ -->
3835<div class="doc_subsubsection">
3836 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3837</div>
3838<div class="doc_text">
3839
3840<h5>Syntax:</h5>
3841<pre>
3842 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3843</pre>
3844
3845<h5>Overview:</h5>
3846<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
3847a pointer type, <tt>ty2</tt>.</p>
3848
3849<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3850<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3851value to cast, and a type to cast it to, which must be a
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3852<a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3853
3854<h5>Semantics:</h5>
3855<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
3856<tt>ty2</tt> by applying either a zero extension or a truncation depending on
3857the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
3858size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
3859the size of a pointer then a zero extension is done. If they are the same size,
3860nothing is done (<i>no-op cast</i>).</p>
3861
3862<h5>Example:</h5>
3863<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3864 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
3865 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
3866 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3867</pre>
3868</div>
3869
3870<!-- _______________________________________________________________________ -->
3871<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3872 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3873</div>
3874<div class="doc_text">
3875
3876<h5>Syntax:</h5>
3877<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3878 &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]3879</pre>
3880
3881<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3882
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3883<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3884<tt>ty2</tt> without changing any bits.</p>
3885
3886<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3887
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3888<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Dan Gohman500233a2008-09-08 16:45:59 +0000[diff] [blame]3889a non-aggregate first class value, and a type to cast it to, which must also be
3890a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
3891<tt>value</tt>
Reid Spencer19b569f2007-01-09 20:08:58 +0000[diff] [blame]3892and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3893type is a pointer, the destination type must also be a pointer. This
3894instruction supports bitwise conversion of vectors to integers and to vectors
3895of other types (as long as they have the same size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3896
3897<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3898<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3899<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
3900this conversion. The conversion is done as if the <tt>value</tt> had been
3901stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
3902converted to other pointer types with this instruction. To convert pointers to
3903other types, use the <a href="#i_inttoptr">inttoptr</a> or
3904<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3905
3906<h5>Example:</h5>
3907<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3908 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3909 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3910 %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]3911</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3912</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3913
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3914<!-- ======================================================================= -->
3915<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
3916<div class="doc_text">
3917<p>The instructions in this category are the "miscellaneous"
3918instructions, which defy better classification.</p>
3919</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3920
3921<!-- _______________________________________________________________________ -->
3922<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
3923</div>
3924<div class="doc_text">
3925<h5>Syntax:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3926<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]3927</pre>
3928<h5>Overview:</h5>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]3929<p>The '<tt>icmp</tt>' instruction returns a boolean value or
3930a vector of boolean values based on comparison
3931of its two integer, integer vector, or pointer operands.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3932<h5>Arguments:</h5>
3933<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3934the condition code indicating the kind of comparison to perform. It is not
3935a value, just a keyword. The possible condition code are:
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3936</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3937<ol>
3938 <li><tt>eq</tt>: equal</li>
3939 <li><tt>ne</tt>: not equal </li>
3940 <li><tt>ugt</tt>: unsigned greater than</li>
3941 <li><tt>uge</tt>: unsigned greater or equal</li>
3942 <li><tt>ult</tt>: unsigned less than</li>
3943 <li><tt>ule</tt>: unsigned less or equal</li>
3944 <li><tt>sgt</tt>: signed greater than</li>
3945 <li><tt>sge</tt>: signed greater or equal</li>
3946 <li><tt>slt</tt>: signed less than</li>
3947 <li><tt>sle</tt>: signed less or equal</li>
3948</ol>
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3949<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]3950<a href="#t_pointer">pointer</a>
3951or integer <a href="#t_vector">vector</a> typed.
3952They must also be identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3953<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3954<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]3955the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]3956yields 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]3957</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3958<ol>
3959 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
3960 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3961 </li>
3962 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3963 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3964 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3965 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3966 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3967 <tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3968 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3969 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3970 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3971 <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]3972 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3973 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3974 <li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3975 <tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3976 <li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3977 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3978 <li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3979 <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]3980</ol>
3981<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3982values are compared as if they were integers.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]3983<p>If the operands are integer vectors, then they are compared
3984element by element. The result is an <tt>i1</tt> vector with
3985the same number of elements as the values being compared.
3986Otherwise, the result is an <tt>i1</tt>.
3987</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3988
3989<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3990<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
3991 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
3992 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
3993 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
3994 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
3995 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3996</pre>
3997</div>
3998
3999<!-- _______________________________________________________________________ -->
4000<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4001</div>
4002<div class="doc_text">
4003<h5>Syntax:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4004<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]4005</pre>
4006<h5>Overview:</h5>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4007<p>The '<tt>fcmp</tt>' instruction returns a boolean value
4008or vector of boolean values based on comparison
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4009of its operands.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4010<p>
4011If the operands are floating point scalars, then the result
4012type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
4013</p>
4014<p>If the operands are floating point vectors, then the result type
4015is a vector of boolean with the same number of elements as the
4016operands being compared.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4017<h5>Arguments:</h5>
4018<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4019the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4020a value, just a keyword. The possible condition code are:</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4021<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4022 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4023 <li><tt>oeq</tt>: ordered and equal</li>
4024 <li><tt>ogt</tt>: ordered and greater than </li>
4025 <li><tt>oge</tt>: ordered and greater than or equal</li>
4026 <li><tt>olt</tt>: ordered and less than </li>
4027 <li><tt>ole</tt>: ordered and less than or equal</li>
4028 <li><tt>one</tt>: ordered and not equal</li>
4029 <li><tt>ord</tt>: ordered (no nans)</li>
4030 <li><tt>ueq</tt>: unordered or equal</li>
4031 <li><tt>ugt</tt>: unordered or greater than </li>
4032 <li><tt>uge</tt>: unordered or greater than or equal</li>
4033 <li><tt>ult</tt>: unordered or less than </li>
4034 <li><tt>ule</tt>: unordered or less than or equal</li>
4035 <li><tt>une</tt>: unordered or not equal</li>
4036 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4037 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4038</ol>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4039<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer93a49852006-12-06 07:08:07 +0000[diff] [blame]4040<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4041<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
4042either a <a href="#t_floating">floating point</a> type
4043or a <a href="#t_vector">vector</a> of floating point type.
4044They must have identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4045<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4046<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4047according to the condition code given as <tt>cond</tt>.
4048If the operands are vectors, then the vectors are compared
4049element by element.
4050Each comparison performed
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4051always yields an <a href="#t_primitive">i1</a> result, as follows:</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4052<ol>
4053 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4054 <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]4055 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4056 <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]4057 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4058 <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]4059 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4060 <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]4061 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4062 <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]4063 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4064 <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]4065 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4066 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
4067 <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]4068 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4069 <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]4070 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4071 <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]4072 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4073 <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]4074 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4075 <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]4076 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4077 <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]4078 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4079 <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]4080 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4081</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4082
4083<h5>Example:</h5>
4084<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]4085 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4086 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4087 &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]4088</pre>
4089</div>
4090
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4091<!-- _______________________________________________________________________ -->
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4092<div class="doc_subsubsection">
4093 <a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
4094</div>
4095<div class="doc_text">
4096<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4097<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]4098</pre>
4099<h5>Overview:</h5>
4100<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
4101element-wise comparison of its two integer vector operands.</p>
4102<h5>Arguments:</h5>
4103<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
4104the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4105a value, just a keyword. The possible condition code are:</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4106<ol>
4107 <li><tt>eq</tt>: equal</li>
4108 <li><tt>ne</tt>: not equal </li>
4109 <li><tt>ugt</tt>: unsigned greater than</li>
4110 <li><tt>uge</tt>: unsigned greater or equal</li>
4111 <li><tt>ult</tt>: unsigned less than</li>
4112 <li><tt>ule</tt>: unsigned less or equal</li>
4113 <li><tt>sgt</tt>: signed greater than</li>
4114 <li><tt>sge</tt>: signed greater or equal</li>
4115 <li><tt>slt</tt>: signed less than</li>
4116 <li><tt>sle</tt>: signed less or equal</li>
4117</ol>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4118<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4119<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
4120<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4121<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4122according to the condition code given as <tt>cond</tt>. The comparison yields a
4123<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
4124identical type as the values being compared. The most significant bit in each
4125element is 1 if the element-wise comparison evaluates to true, and is 0
4126otherwise. All other bits of the result are undefined. The condition codes
4127are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4128instruction</a>.</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4129
4130<h5>Example:</h5>
4131<pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4132 &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>
4133 &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]4134</pre>
4135</div>
4136
4137<!-- _______________________________________________________________________ -->
4138<div class="doc_subsubsection">
4139 <a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
4140</div>
4141<div class="doc_text">
4142<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4143<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]4144<h5>Overview:</h5>
4145<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
4146element-wise comparison of its two floating point vector operands. The output
4147elements have the same width as the input elements.</p>
4148<h5>Arguments:</h5>
4149<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
4150the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4151a value, just a keyword. The possible condition code are:</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4152<ol>
4153 <li><tt>false</tt>: no comparison, always returns false</li>
4154 <li><tt>oeq</tt>: ordered and equal</li>
4155 <li><tt>ogt</tt>: ordered and greater than </li>
4156 <li><tt>oge</tt>: ordered and greater than or equal</li>
4157 <li><tt>olt</tt>: ordered and less than </li>
4158 <li><tt>ole</tt>: ordered and less than or equal</li>
4159 <li><tt>one</tt>: ordered and not equal</li>
4160 <li><tt>ord</tt>: ordered (no nans)</li>
4161 <li><tt>ueq</tt>: unordered or equal</li>
4162 <li><tt>ugt</tt>: unordered or greater than </li>
4163 <li><tt>uge</tt>: unordered or greater than or equal</li>
4164 <li><tt>ult</tt>: unordered or less than </li>
4165 <li><tt>ule</tt>: unordered or less than or equal</li>
4166 <li><tt>une</tt>: unordered or not equal</li>
4167 <li><tt>uno</tt>: unordered (either nans)</li>
4168 <li><tt>true</tt>: no comparison, always returns true</li>
4169</ol>
4170<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
4171<a href="#t_floating">floating point</a> typed. They must also be identical
4172types.</p>
4173<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4174<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4175according to the condition code given as <tt>cond</tt>. The comparison yields a
4176<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
4177an identical number of elements as the values being compared, and each element
4178having identical with to the width of the floating point elements. The most
4179significant bit in each element is 1 if the element-wise comparison evaluates to
4180true, and is 0 otherwise. All other bits of the result are undefined. The
4181condition codes are evaluated identically to the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4182<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4183
4184<h5>Example:</h5>
4185<pre>
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]4186 <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0, i32 -1 &gt;</i>
4187 &lt;result&gt; = vfcmp oeq &lt;2 x float&gt; &lt; float 4, float 0 &gt;, &lt; float 5, float 0 &gt;
4188
4189 <i>; yields: result=&lt;2 x i64&gt; &lt; i64 -1, i64 0 &gt;</i>
4190 &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]4191</pre>
4192</div>
4193
4194<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4195<div class="doc_subsubsection">
4196 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4197</div>
4198
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4199<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4200
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4201<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4202
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4203<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
4204<h5>Overview:</h5>
4205<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
4206the SSA graph representing the function.</p>
4207<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4208
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4209<p>The type of the incoming values is specified with the first type
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4210field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
4211as arguments, with one pair for each predecessor basic block of the
4212current block. Only values of <a href="#t_firstclass">first class</a>
4213type may be used as the value arguments to the PHI node. Only labels
4214may be used as the label arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4215
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4216<p>There must be no non-phi instructions between the start of a basic
4217block and the PHI instructions: i.e. PHI instructions must be first in
4218a basic block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4219
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4220<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4221
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4222<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
4223specified by the pair corresponding to the predecessor basic block that executed
4224just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4225
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4226<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4227<pre>
4228Loop: ; Infinite loop that counts from 0 on up...
4229 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4230 %nextindvar = add i32 %indvar, 1
4231 br label %Loop
4232</pre>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4233</div>
4234
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4235<!-- _______________________________________________________________________ -->
4236<div class="doc_subsubsection">
4237 <a name="i_select">'<tt>select</tt>' Instruction</a>
4238</div>
4239
4240<div class="doc_text">
4241
4242<h5>Syntax:</h5>
4243
4244<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4245 &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>
4246
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4247 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4248</pre>
4249
4250<h5>Overview:</h5>
4251
4252<p>
4253The '<tt>select</tt>' instruction is used to choose one value based on a
4254condition, without branching.
4255</p>
4256
4257
4258<h5>Arguments:</h5>
4259
4260<p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4261The '<tt>select</tt>' instruction requires an 'i1' value or
4262a vector of 'i1' values indicating the
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4263condition, and two values of the same <a href="#t_firstclass">first class</a>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4264type. If the val1/val2 are vectors and
4265the condition is a scalar, then entire vectors are selected, not
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4266individual elements.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4267</p>
4268
4269<h5>Semantics:</h5>
4270
4271<p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4272If 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]4273value argument; otherwise, it returns the second value argument.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4274</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4275<p>
4276If the condition is a vector of i1, then the value arguments must
4277be vectors of the same size, and the selection is done element
4278by element.
4279</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4280
4281<h5>Example:</h5>
4282
4283<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4284 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4285</pre>
4286</div>
4287
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]4288
4289<!-- _______________________________________________________________________ -->
4290<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4291 <a name="i_call">'<tt>call</tt>' Instruction</a>
4292</div>
4293
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4294<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4295
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4296<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4297<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]4298 &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]4299</pre>
4300
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4301<h5>Overview:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4302
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4303<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4304
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4305<h5>Arguments:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4306
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4307<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4308
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4309<ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4310 <li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4311 <p>The optional "tail" marker indicates whether the callee function accesses
4312 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4313 function call is eligible for tail call optimization. Note that calls may
4314 be marked "tail" even if they do not occur before a <a
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4315 href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4316 </li>
4317 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4318 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4319 convention</a> the call should use. If none is specified, the call defaults
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4320 to using C calling conventions.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4321 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4322
4323 <li>
4324 <p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4325 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
4326 and '<tt>inreg</tt>' attributes are valid here.</p>
4327 </li>
4328
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4329 <li>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4330 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
4331 the type of the return value. Functions that return no value are marked
4332 <tt><a href="#t_void">void</a></tt>.</p>
4333 </li>
4334 <li>
4335 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
4336 value being invoked. The argument types must match the types implied by
4337 this signature. This type can be omitted if the function is not varargs
4338 and if the function type does not return a pointer to a function.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4339 </li>
4340 <li>
4341 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4342 be invoked. In most cases, this is a direct function invocation, but
4343 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4344 to function value.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4345 </li>
4346 <li>
4347 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencera7e302a2005-05-01 22:22:57 +0000[diff] [blame]4348 function signature argument types. All arguments must be of
4349 <a href="#t_firstclass">first class</a> type. If the function signature
4350 indicates the function accepts a variable number of arguments, the extra
4351 arguments can be specified.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4352 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4353 <li>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]4354 <p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4355 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
4356 '<tt>readnone</tt>' attributes are valid here.</p>
4357 </li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4358</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4359
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4360<h5>Semantics:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4361
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4362<p>The '<tt>call</tt>' instruction is used to cause control flow to
4363transfer to a specified function, with its incoming arguments bound to
4364the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
4365instruction in the called function, control flow continues with the
4366instruction after the function call, and the return value of the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4367function is bound to the result argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4368
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4369<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4370
4371<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4372 %retval = call i32 @test(i32 %argc)
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]4373 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4374 %X = tail call i32 @foo() <i>; yields i32</i>
4375 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4376 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]4377
4378 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4379 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]4380 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
4381 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]4382 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]4383 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4384</pre>
4385
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4386</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4387
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4388<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4389<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]4390 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4391</div>
4392
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4393<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4394
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4395<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4396
4397<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4398 &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]4399</pre>
4400
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4401<h5>Overview:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4402
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4403<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4404the "variable argument" area of a function call. It is used to implement the
4405<tt>va_arg</tt> macro in C.</p>
4406
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4407<h5>Arguments:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4408
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4409<p>This instruction takes a <tt>va_list*</tt> value and the type of
4410the argument. It returns a value of the specified argument type and
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4411increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4412actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4413
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4414<h5>Semantics:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4415
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4416<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
4417type from the specified <tt>va_list</tt> and causes the
4418<tt>va_list</tt> to point to the next argument. For more information,
4419see the variable argument handling <a href="#int_varargs">Intrinsic
4420Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4421
4422<p>It is legal for this instruction to be called in a function which does not
4423take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4424function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4425
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4426<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4427href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4428argument.</p>
4429
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4430<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4431
4432<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4433
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4434</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4435
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4436<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4437<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4438<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4439
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4440<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4441
4442<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4443well known names and semantics and are required to follow certain restrictions.
4444Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4445language that does not require changing all of the transformations in LLVM when
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]4446adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4447
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4448<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4449prefix is reserved in LLVM for intrinsic names; thus, function names may not
4450begin with this prefix. Intrinsic functions must always be external functions:
4451you cannot define the body of intrinsic functions. Intrinsic functions may
4452only be used in call or invoke instructions: it is illegal to take the address
4453of an intrinsic function. Additionally, because intrinsic functions are part
4454of the LLVM language, it is required if any are added that they be documented
4455here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4456
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4457<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
4458a family of functions that perform the same operation but on different data
4459types. Because LLVM can represent over 8 million different integer types,
4460overloading is used commonly to allow an intrinsic function to operate on any
4461integer type. One or more of the argument types or the result type can be
4462overloaded to accept any integer type. Argument types may also be defined as
4463exactly matching a previous argument's type or the result type. This allows an
4464intrinsic function which accepts multiple arguments, but needs all of them to
4465be of the same type, to only be overloaded with respect to a single argument or
4466the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4467
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4468<p>Overloaded intrinsics will have the names of its overloaded argument types
4469encoded into its function name, each preceded by a period. Only those types
4470which are overloaded result in a name suffix. Arguments whose type is matched
4471against another type do not. For example, the <tt>llvm.ctpop</tt> function can
4472take an integer of any width and returns an integer of exactly the same integer
4473width. This leads to a family of functions such as
4474<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
4475Only one type, the return type, is overloaded, and only one type suffix is
4476required. Because the argument's type is matched against the return type, it
4477does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4478
4479<p>To learn how to add an intrinsic function, please see the
4480<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4481</p>
4482
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4483</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4484
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4485<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4486<div class="doc_subsection">
4487 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
4488</div>
4489
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4490<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4491
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4492<p>Variable argument support is defined in LLVM with the <a
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]4493 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4494intrinsic functions. These functions are related to the similarly
4495named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4496
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4497<p>All of these functions operate on arguments that use a
4498target-specific value type "<tt>va_list</tt>". The LLVM assembly
4499language reference manual does not define what this type is, so all
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4500transformations should be prepared to handle these functions regardless of
4501the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4502
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]4503<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]4504instruction and the variable argument handling intrinsic functions are
4505used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4506
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4507<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4508<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4509define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4510 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4511 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4512 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4513 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4514
4515 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4516 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4517
4518 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4519 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4520 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4521 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4522 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4523
4524 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4525 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4526 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4527}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4528
4529declare void @llvm.va_start(i8*)
4530declare void @llvm.va_copy(i8*, i8*)
4531declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4532</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4533</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4534
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4535</div>
4536
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4537<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4538<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4539 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4540</div>
4541
4542
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4543<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4544<h5>Syntax:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4545<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4546<h5>Overview:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4547<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4548<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
4549href="#i_va_arg">va_arg</a></tt>.</p>
4550
4551<h5>Arguments:</h5>
4552
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4553<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]4554
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4555<h5>Semantics:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4556
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4557<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]4558macro available in C. In a target-dependent way, it initializes the
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4559<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]4560<tt>va_arg</tt> will produce the first variable argument passed to the function.
4561Unlike 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]4562last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4563
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4564</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4565
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4566<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4567<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4568 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4569</div>
4570
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4571<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4572<h5>Syntax:</h5>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4573<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4574<h5>Overview:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4575
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4576<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4577which 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]4578or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4579
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4580<h5>Arguments:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4581
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4582<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]4583
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4584<h5>Semantics:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4585
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4586<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]4587macro available in C. In a target-dependent way, it destroys the
4588<tt>va_list</tt> element to which the argument points. Calls to <a
4589href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
4590<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
4591<tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4592
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4593</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4594
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4595<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4596<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4597 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4598</div>
4599
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4600<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4601
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4602<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4603
4604<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4605 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4606</pre>
4607
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4608<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4609
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4610<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
4611from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4612
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4613<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4614
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4615<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]4616The 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]4617
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4618
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4619<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4620
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4621<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
4622macro available in C. In a target-dependent way, it copies the source
4623<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
4624intrinsic is necessary because the <tt><a href="#int_va_start">
4625llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
4626example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4627
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4628</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4629
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4630<!-- ======================================================================= -->
4631<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4632 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
4633</div>
4634
4635<div class="doc_text">
4636
4637<p>
4638LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]4639Collection</a> (GC) requires the implementation and generation of these
4640intrinsics.
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4641These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4642stack</a>, as well as garbage collector implementations that require <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4643href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4644Front-ends for type-safe garbage collected languages should generate these
4645intrinsics to make use of the LLVM garbage collectors. For more details, see <a
4646href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
4647</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]4648
4649<p>The garbage collection intrinsics only operate on objects in the generic
4650 address space (address space zero).</p>
4651
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4652</div>
4653
4654<!-- _______________________________________________________________________ -->
4655<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4656 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4657</div>
4658
4659<div class="doc_text">
4660
4661<h5>Syntax:</h5>
4662
4663<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4664 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4665</pre>
4666
4667<h5>Overview:</h5>
4668
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]4669<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]4670the code generator, and allows some metadata to be associated with it.</p>
4671
4672<h5>Arguments:</h5>
4673
4674<p>The first argument specifies the address of a stack object that contains the
4675root pointer. The second pointer (which must be either a constant or a global
4676value address) contains the meta-data to be associated with the root.</p>
4677
4678<h5>Semantics:</h5>
4679
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]4680<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]4681location. At compile-time, the code generator generates information to allow
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4682the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
4683intrinsic may only be used in a function which <a href="#gc">specifies a GC
4684algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4685
4686</div>
4687
4688
4689<!-- _______________________________________________________________________ -->
4690<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4691 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4692</div>
4693
4694<div class="doc_text">
4695
4696<h5>Syntax:</h5>
4697
4698<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4699 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4700</pre>
4701
4702<h5>Overview:</h5>
4703
4704<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4705locations, allowing garbage collector implementations that require read
4706barriers.</p>
4707
4708<h5>Arguments:</h5>
4709
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4710<p>The second argument is the address to read from, which should be an address
4711allocated from the garbage collector. The first object is a pointer to the
4712start of the referenced object, if needed by the language runtime (otherwise
4713null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4714
4715<h5>Semantics:</h5>
4716
4717<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4718instruction, but may be replaced with substantially more complex code by the
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4719garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
4720may only be used in a function which <a href="#gc">specifies a GC
4721algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4722
4723</div>
4724
4725
4726<!-- _______________________________________________________________________ -->
4727<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4728 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4729</div>
4730
4731<div class="doc_text">
4732
4733<h5>Syntax:</h5>
4734
4735<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4736 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4737</pre>
4738
4739<h5>Overview:</h5>
4740
4741<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4742locations, allowing garbage collector implementations that require write
4743barriers (such as generational or reference counting collectors).</p>
4744
4745<h5>Arguments:</h5>
4746
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4747<p>The first argument is the reference to store, the second is the start of the
4748object to store it to, and the third is the address of the field of Obj to
4749store to. If the runtime does not require a pointer to the object, Obj may be
4750null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4751
4752<h5>Semantics:</h5>
4753
4754<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4755instruction, but may be replaced with substantially more complex code by the
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4756garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
4757may only be used in a function which <a href="#gc">specifies a GC
4758algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4759
4760</div>
4761
4762
4763
4764<!-- ======================================================================= -->
4765<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4766 <a name="int_codegen">Code Generator Intrinsics</a>
4767</div>
4768
4769<div class="doc_text">
4770<p>
4771These intrinsics are provided by LLVM to expose special features that may only
4772be implemented with code generator support.
4773</p>
4774
4775</div>
4776
4777<!-- _______________________________________________________________________ -->
4778<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4779 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4780</div>
4781
4782<div class="doc_text">
4783
4784<h5>Syntax:</h5>
4785<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4786 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4787</pre>
4788
4789<h5>Overview:</h5>
4790
4791<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4792The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4793target-specific value indicating the return address of the current function
4794or one of its callers.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4795</p>
4796
4797<h5>Arguments:</h5>
4798
4799<p>
4800The argument to this intrinsic indicates which function to return the address
4801for. Zero indicates the calling function, one indicates its caller, etc. The
4802argument is <b>required</b> to be a constant integer value.
4803</p>
4804
4805<h5>Semantics:</h5>
4806
4807<p>
4808The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4809the return address of the specified call frame, or zero if it cannot be
4810identified. The value returned by this intrinsic is likely to be incorrect or 0
4811for arguments other than zero, so it should only be used for debugging purposes.
4812</p>
4813
4814<p>
4815Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4816aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4817source-language caller.
4818</p>
4819</div>
4820
4821
4822<!-- _______________________________________________________________________ -->
4823<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4824 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4825</div>
4826
4827<div class="doc_text">
4828
4829<h5>Syntax:</h5>
4830<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4831 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4832</pre>
4833
4834<h5>Overview:</h5>
4835
4836<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4837The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
4838target-specific frame pointer value for the specified stack frame.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4839</p>
4840
4841<h5>Arguments:</h5>
4842
4843<p>
4844The argument to this intrinsic indicates which function to return the frame
4845pointer for. Zero indicates the calling function, one indicates its caller,
4846etc. The argument is <b>required</b> to be a constant integer value.
4847</p>
4848
4849<h5>Semantics:</h5>
4850
4851<p>
4852The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
4853the frame address of the specified call frame, or zero if it cannot be
4854identified. The value returned by this intrinsic is likely to be incorrect or 0
4855for arguments other than zero, so it should only be used for debugging purposes.
4856</p>
4857
4858<p>
4859Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4860aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4861source-language caller.
4862</p>
4863</div>
4864
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4865<!-- _______________________________________________________________________ -->
4866<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4867 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4868</div>
4869
4870<div class="doc_text">
4871
4872<h5>Syntax:</h5>
4873<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4874 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4875</pre>
4876
4877<h5>Overview:</h5>
4878
4879<p>
4880The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4881the function stack, for use with <a href="#int_stackrestore">
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4882<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
4883features like scoped automatic variable sized arrays in C99.
4884</p>
4885
4886<h5>Semantics:</h5>
4887
4888<p>
4889This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4890href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4891<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
4892<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
4893state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
4894practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
4895that were allocated after the <tt>llvm.stacksave</tt> was executed.
4896</p>
4897
4898</div>
4899
4900<!-- _______________________________________________________________________ -->
4901<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4902 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4903</div>
4904
4905<div class="doc_text">
4906
4907<h5>Syntax:</h5>
4908<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4909 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4910</pre>
4911
4912<h5>Overview:</h5>
4913
4914<p>
4915The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
4916the function stack to the state it was in when the corresponding <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4917href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4918useful for implementing language features like scoped automatic variable sized
4919arrays in C99.
4920</p>
4921
4922<h5>Semantics:</h5>
4923
4924<p>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4925See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4926</p>
4927
4928</div>
4929
4930
4931<!-- _______________________________________________________________________ -->
4932<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4933 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4934</div>
4935
4936<div class="doc_text">
4937
4938<h5>Syntax:</h5>
4939<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4940 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]4941</pre>
4942
4943<h5>Overview:</h5>
4944
4945
4946<p>
4947The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4948a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
4949no
4950effect on the behavior of the program but can change its performance
Chris Lattner2a615362005-02-28 19:47:14 +0000[diff] [blame]4951characteristics.
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4952</p>
4953
4954<h5>Arguments:</h5>
4955
4956<p>
4957<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
4958determining if the fetch should be for a read (0) or write (1), and
4959<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattneraeffb4a2005-03-07 20:31:38 +0000[diff] [blame]4960locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4961<tt>locality</tt> arguments must be constant integers.
4962</p>
4963
4964<h5>Semantics:</h5>
4965
4966<p>
4967This intrinsic does not modify the behavior of the program. In particular,
4968prefetches cannot trap and do not produce a value. On targets that support this
4969intrinsic, the prefetch can provide hints to the processor cache for better
4970performance.
4971</p>
4972
4973</div>
4974
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4975<!-- _______________________________________________________________________ -->
4976<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4977 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4978</div>
4979
4980<div class="doc_text">
4981
4982<h5>Syntax:</h5>
4983<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4984 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4985</pre>
4986
4987<h5>Overview:</h5>
4988
4989
4990<p>
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4991The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]4992(PC) in a region of
4993code to simulators and other tools. The method is target specific, but it is
4994expected that the marker will use exported symbols to transmit the PC of the
4995marker.
4996The marker makes no guarantees that it will remain with any specific instruction
4997after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb3e7afd2006-03-24 07:16:10 +0000[diff] [blame]4998optimizations. The intended use is to be inserted after optimizations to allow
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4999correlations of simulation runs.
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5000</p>
5001
5002<h5>Arguments:</h5>
5003
5004<p>
5005<tt>id</tt> is a numerical id identifying the marker.
5006</p>
5007
5008<h5>Semantics:</h5>
5009
5010<p>
5011This intrinsic does not modify the behavior of the program. Backends that do not
5012support this intrinisic may ignore it.
5013</p>
5014
5015</div>
5016
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5017<!-- _______________________________________________________________________ -->
5018<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5019 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5020</div>
5021
5022<div class="doc_text">
5023
5024<h5>Syntax:</h5>
5025<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5026 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5027</pre>
5028
5029<h5>Overview:</h5>
5030
5031
5032<p>
5033The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5034counter register (or similar low latency, high accuracy clocks) on those targets
5035that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
5036As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
5037should only be used for small timings.
5038</p>
5039
5040<h5>Semantics:</h5>
5041
5042<p>
5043When directly supported, reading the cycle counter should not modify any memory.
5044Implementations are allowed to either return a application specific value or a
5045system wide value. On backends without support, this is lowered to a constant 0.
5046</p>
5047
5048</div>
5049
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5050<!-- ======================================================================= -->
5051<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5052 <a name="int_libc">Standard C Library Intrinsics</a>
5053</div>
5054
5055<div class="doc_text">
5056<p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5057LLVM provides intrinsics for a few important standard C library functions.
5058These intrinsics allow source-language front-ends to pass information about the
5059alignment of the pointer arguments to the code generator, providing opportunity
5060for more efficient code generation.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5061</p>
5062
5063</div>
5064
5065<!-- _______________________________________________________________________ -->
5066<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5067 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5068</div>
5069
5070<div class="doc_text">
5071
5072<h5>Syntax:</h5>
5073<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5074 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5075 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5076 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5077 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5078</pre>
5079
5080<h5>Overview:</h5>
5081
5082<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5083The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5084location to the destination location.
5085</p>
5086
5087<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5088Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5089intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5090</p>
5091
5092<h5>Arguments:</h5>
5093
5094<p>
5095The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5096the source. The third argument is an integer argument
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5097specifying the number of bytes to copy, and the fourth argument is the alignment
5098of the source and destination locations.
5099</p>
5100
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5101<p>
5102If 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]5103the caller guarantees that both the source and destination pointers are aligned
5104to that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5105</p>
5106
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5107<h5>Semantics:</h5>
5108
5109<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5110The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5111location to the destination location, which are not allowed to overlap. It
5112copies "len" bytes of memory over. If the argument is known to be aligned to
5113some boundary, this can be specified as the fourth argument, otherwise it should
5114be set to 0 or 1.
5115</p>
5116</div>
5117
5118
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5119<!-- _______________________________________________________________________ -->
5120<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5121 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5122</div>
5123
5124<div class="doc_text">
5125
5126<h5>Syntax:</h5>
5127<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5128 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5129 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5130 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5131 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5132</pre>
5133
5134<h5>Overview:</h5>
5135
5136<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5137The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
5138location to the destination location. It is similar to the
Chris Lattner4b2cbcf2008-01-06 19:51:52 +0000[diff] [blame]5139'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5140</p>
5141
5142<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5143Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5144intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5145</p>
5146
5147<h5>Arguments:</h5>
5148
5149<p>
5150The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5151the source. The third argument is an integer argument
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5152specifying the number of bytes to copy, and the fourth argument is the alignment
5153of the source and destination locations.
5154</p>
5155
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5156<p>
5157If 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]5158the caller guarantees that the source and destination pointers are aligned to
5159that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5160</p>
5161
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5162<h5>Semantics:</h5>
5163
5164<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5165The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5166location to the destination location, which may overlap. It
5167copies "len" bytes of memory over. If the argument is known to be aligned to
5168some boundary, this can be specified as the fourth argument, otherwise it should
5169be set to 0 or 1.
5170</p>
5171</div>
5172
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5173
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5174<!-- _______________________________________________________________________ -->
5175<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5176 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5177</div>
5178
5179<div class="doc_text">
5180
5181<h5>Syntax:</h5>
5182<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5183 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5184 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5185 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5186 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5187</pre>
5188
5189<h5>Overview:</h5>
5190
5191<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5192The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5193byte value.
5194</p>
5195
5196<p>
5197Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
5198does not return a value, and takes an extra alignment argument.
5199</p>
5200
5201<h5>Arguments:</h5>
5202
5203<p>
5204The first argument is a pointer to the destination to fill, the second is the
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5205byte value to fill it with, the third argument is an integer
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5206argument specifying the number of bytes to fill, and the fourth argument is the
5207known alignment of destination location.
5208</p>
5209
5210<p>
5211If 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]5212the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5213</p>
5214
5215<h5>Semantics:</h5>
5216
5217<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5218The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
5219the
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5220destination location. If the argument is known to be aligned to some boundary,
5221this can be specified as the fourth argument, otherwise it should be set to 0 or
52221.
5223</p>
5224</div>
5225
5226
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5227<!-- _______________________________________________________________________ -->
5228<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5229 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5230</div>
5231
5232<div class="doc_text">
5233
5234<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5235<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]5236floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5237types however.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5238<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5239 declare float @llvm.sqrt.f32(float %Val)
5240 declare double @llvm.sqrt.f64(double %Val)
5241 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5242 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5243 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5244</pre>
5245
5246<h5>Overview:</h5>
5247
5248<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5249The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5250returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5251<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner103e2d72008-01-29 07:00:44 +0000[diff] [blame]5252negative numbers other than -0.0 (which allows for better optimization, because
5253there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
5254defined to return -0.0 like IEEE sqrt.
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5255</p>
5256
5257<h5>Arguments:</h5>
5258
5259<p>
5260The argument and return value are floating point numbers of the same type.
5261</p>
5262
5263<h5>Semantics:</h5>
5264
5265<p>
Dan Gohmand6257fe2007-07-16 14:37:41 +0000[diff] [blame]5266This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5267floating point number.
5268</p>
5269</div>
5270
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5271<!-- _______________________________________________________________________ -->
5272<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5273 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5274</div>
5275
5276<div class="doc_text">
5277
5278<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5279<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]5280floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5281types however.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5282<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5283 declare float @llvm.powi.f32(float %Val, i32 %power)
5284 declare double @llvm.powi.f64(double %Val, i32 %power)
5285 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5286 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5287 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5288</pre>
5289
5290<h5>Overview:</h5>
5291
5292<p>
5293The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5294specified (positive or negative) power. The order of evaluation of
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5295multiplications is not defined. When a vector of floating point type is
5296used, the second argument remains a scalar integer value.
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5297</p>
5298
5299<h5>Arguments:</h5>
5300
5301<p>
5302The second argument is an integer power, and the first is a value to raise to
5303that power.
5304</p>
5305
5306<h5>Semantics:</h5>
5307
5308<p>
5309This function returns the first value raised to the second power with an
5310unspecified sequence of rounding operations.</p>
5311</div>
5312
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5313<!-- _______________________________________________________________________ -->
5314<div class="doc_subsubsection">
5315 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5316</div>
5317
5318<div class="doc_text">
5319
5320<h5>Syntax:</h5>
5321<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5322floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5323types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5324<pre>
5325 declare float @llvm.sin.f32(float %Val)
5326 declare double @llvm.sin.f64(double %Val)
5327 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5328 declare fp128 @llvm.sin.f128(fp128 %Val)
5329 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5330</pre>
5331
5332<h5>Overview:</h5>
5333
5334<p>
5335The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
5336</p>
5337
5338<h5>Arguments:</h5>
5339
5340<p>
5341The argument and return value are floating point numbers of the same type.
5342</p>
5343
5344<h5>Semantics:</h5>
5345
5346<p>
5347This function returns the sine of the specified operand, returning the
5348same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5349conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5350</div>
5351
5352<!-- _______________________________________________________________________ -->
5353<div class="doc_subsubsection">
5354 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5355</div>
5356
5357<div class="doc_text">
5358
5359<h5>Syntax:</h5>
5360<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5361floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5362types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5363<pre>
5364 declare float @llvm.cos.f32(float %Val)
5365 declare double @llvm.cos.f64(double %Val)
5366 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5367 declare fp128 @llvm.cos.f128(fp128 %Val)
5368 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5369</pre>
5370
5371<h5>Overview:</h5>
5372
5373<p>
5374The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
5375</p>
5376
5377<h5>Arguments:</h5>
5378
5379<p>
5380The argument and return value are floating point numbers of the same type.
5381</p>
5382
5383<h5>Semantics:</h5>
5384
5385<p>
5386This function returns the cosine of the specified operand, returning the
5387same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5388conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5389</div>
5390
5391<!-- _______________________________________________________________________ -->
5392<div class="doc_subsubsection">
5393 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5394</div>
5395
5396<div class="doc_text">
5397
5398<h5>Syntax:</h5>
5399<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5400floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5401types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5402<pre>
5403 declare float @llvm.pow.f32(float %Val, float %Power)
5404 declare double @llvm.pow.f64(double %Val, double %Power)
5405 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5406 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5407 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5408</pre>
5409
5410<h5>Overview:</h5>
5411
5412<p>
5413The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5414specified (positive or negative) power.
5415</p>
5416
5417<h5>Arguments:</h5>
5418
5419<p>
5420The second argument is a floating point power, and the first is a value to
5421raise to that power.
5422</p>
5423
5424<h5>Semantics:</h5>
5425
5426<p>
5427This function returns the first value raised to the second power,
5428returning the
5429same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5430conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5431</div>
5432
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5433
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5434<!-- ======================================================================= -->
5435<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5436 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5437</div>
5438
5439<div class="doc_text">
5440<p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5441LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5442These allow efficient code generation for some algorithms.
5443</p>
5444
5445</div>
5446
5447<!-- _______________________________________________________________________ -->
5448<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5449 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5450</div>
5451
5452<div class="doc_text">
5453
5454<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5455<p>This is an overloaded intrinsic function. You can use bswap on any integer
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5456type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5457<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5458 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5459 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5460 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5461</pre>
5462
5463<h5>Overview:</h5>
5464
5465<p>
Reid Spencer338ea092007-04-02 02:25:19 +0000[diff] [blame]5466The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5467values with an even number of bytes (positive multiple of 16 bits). These are
5468useful for performing operations on data that is not in the target's native
5469byte order.
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5470</p>
5471
5472<h5>Semantics:</h5>
5473
5474<p>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5475The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5476and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
5477intrinsic returns an i32 value that has the four bytes of the input i32
5478swapped, 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]5479i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
5480<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5481additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5482</p>
5483
5484</div>
5485
5486<!-- _______________________________________________________________________ -->
5487<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5488 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5489</div>
5490
5491<div class="doc_text">
5492
5493<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5494<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]5495width. Not all targets support all bit widths however.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5496<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5497 declare i8 @llvm.ctpop.i8 (i8 &lt;src&gt;)
5498 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5499 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5500 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5501 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5502</pre>
5503
5504<h5>Overview:</h5>
5505
5506<p>
Chris Lattnerec6cb612006-01-16 22:38:59 +0000[diff] [blame]5507The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
5508value.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5509</p>
5510
5511<h5>Arguments:</h5>
5512
5513<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]5514The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5515integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5516</p>
5517
5518<h5>Semantics:</h5>
5519
5520<p>
5521The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
5522</p>
5523</div>
5524
5525<!-- _______________________________________________________________________ -->
5526<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5527 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5528</div>
5529
5530<div class="doc_text">
5531
5532<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5533<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]5534integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5535<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5536 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5537 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5538 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5539 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5540 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5541</pre>
5542
5543<h5>Overview:</h5>
5544
5545<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5546The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5547leading zeros in a variable.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5548</p>
5549
5550<h5>Arguments:</h5>
5551
5552<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]5553The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5554integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5555</p>
5556
5557<h5>Semantics:</h5>
5558
5559<p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5560The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
5561in 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]5562of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5563</p>
5564</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5565
5566
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5567
5568<!-- _______________________________________________________________________ -->
5569<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5570 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5571</div>
5572
5573<div class="doc_text">
5574
5575<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5576<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]5577integer bit width. Not all targets support all bit widths however.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5578<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5579 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5580 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5581 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5582 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5583 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5584</pre>
5585
5586<h5>Overview:</h5>
5587
5588<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5589The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5590trailing zeros.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5591</p>
5592
5593<h5>Arguments:</h5>
5594
5595<p>
5596The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5597integer type. The return type must match the argument type.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5598</p>
5599
5600<h5>Semantics:</h5>
5601
5602<p>
5603The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
5604in a variable. If the src == 0 then the result is the size in bits of the type
5605of src. For example, <tt>llvm.cttz(2) = 1</tt>.
5606</p>
5607</div>
5608
Reid Spencer497d93e2007-04-01 08:27:01 +0000[diff] [blame]5609<!-- _______________________________________________________________________ -->
5610<div class="doc_subsubsection">
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5611 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5612</div>
5613
5614<div class="doc_text">
5615
5616<h5>Syntax:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5617<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5618on any integer bit width.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5619<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5620 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
5621 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5622</pre>
5623
5624<h5>Overview:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5625<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5626range of bits from an integer value and returns them in the same bit width as
5627the original value.</p>
5628
5629<h5>Arguments:</h5>
5630<p>The first argument, <tt>%val</tt> and the result may be integer types of
5631any bit width but they must have the same bit width. The second and third
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5632arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5633
5634<h5>Semantics:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5635<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5636of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
5637<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
5638operates in forward mode.</p>
5639<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
5640right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5641only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
5642<ol>
5643 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
5644 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
5645 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
5646 to determine the number of bits to retain.</li>
5647 <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]5648 <li>The mask is ANDed with <tt>%val</tt> to produce the result.</li>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5649</ol>
Reid Spencerd6a85b52007-05-14 16:14:57 +0000[diff] [blame]5650<p>In reverse mode, a similar computation is made except that the bits are
5651returned in the reverse order. So, for example, if <tt>X</tt> has the value
5652<tt>i16 0x0ACF (101011001111)</tt> and we apply
5653<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
5654<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5655</div>
5656
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5657<div class="doc_subsubsection">
5658 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
5659</div>
5660
5661<div class="doc_text">
5662
5663<h5>Syntax:</h5>
5664<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5665on any integer bit width.</p>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5666<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5667 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
5668 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]5669</pre>
5670
5671<h5>Overview:</h5>
5672<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
5673of bits in an integer value with another integer value. It returns the integer
5674with the replaced bits.</p>
5675
5676<h5>Arguments:</h5>
5677<p>The first argument, <tt>%val</tt> and the result may be integer types of
5678any bit width but they must have the same bit width. <tt>%val</tt> is the value
5679whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
5680integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
5681type since they specify only a bit index.</p>
5682
5683<h5>Semantics:</h5>
5684<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
5685of operation: forwards and reverse. If <tt>%lo</tt> is greater than
5686<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
5687operates in forward mode.</p>
5688<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
5689truncating it down to the size of the replacement area or zero extending it
5690up to that size.</p>
5691<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5692are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5693in <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]5694to the <tt>%hi</tt>th bit.</p>
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5695<p>In reverse mode, a similar computation is made except that the bits are
5696reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5697<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]5698<h5>Examples:</h5>
5699<pre>
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5700 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5701 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5702 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5703 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5704 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]5705</pre>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5706</div>
5707
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5708<!-- ======================================================================= -->
5709<div class="doc_subsection">
5710 <a name="int_debugger">Debugger Intrinsics</a>
5711</div>
5712
5713<div class="doc_text">
5714<p>
5715The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
5716are described in the <a
5717href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
5718Debugging</a> document.
5719</p>
5720</div>
5721
5722
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]5723<!-- ======================================================================= -->
5724<div class="doc_subsection">
5725 <a name="int_eh">Exception Handling Intrinsics</a>
5726</div>
5727
5728<div class="doc_text">
5729<p> The LLVM exception handling intrinsics (which all start with
5730<tt>llvm.eh.</tt> prefix), are described in the <a
5731href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
5732Handling</a> document. </p>
5733</div>
5734
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5735<!-- ======================================================================= -->
5736<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5737 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5738</div>
5739
5740<div class="doc_text">
5741<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5742 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5743 the <tt>nest</tt> attribute, from a function. The result is a callable
5744 function pointer lacking the nest parameter - the caller does not need
5745 to provide a value for it. Instead, the value to use is stored in
5746 advance in a "trampoline", a block of memory usually allocated
5747 on the stack, which also contains code to splice the nest value into the
5748 argument list. This is used to implement the GCC nested function address
5749 extension.
5750</p>
5751<p>
5752 For example, if the function is
5753 <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]5754 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]5755<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5756 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
5757 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
5758 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
5759 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5760</pre>
Bill Wendling03295ca2007-09-22 09:23:55 +0000[diff] [blame]5761 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
5762 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5763</div>
5764
5765<!-- _______________________________________________________________________ -->
5766<div class="doc_subsubsection">
5767 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
5768</div>
5769<div class="doc_text">
5770<h5>Syntax:</h5>
5771<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5772declare 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]5773</pre>
5774<h5>Overview:</h5>
5775<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5776 This fills the memory pointed to by <tt>tramp</tt> with code
5777 and returns a function pointer suitable for executing it.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5778</p>
5779<h5>Arguments:</h5>
5780<p>
5781 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
5782 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
5783 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsc00c2ba2007-08-22 23:39:54 +0000[diff] [blame]5784 intrinsic. Note that the size and the alignment are target-specific - LLVM
5785 currently provides no portable way of determining them, so a front-end that
5786 generates this intrinsic needs to have some target-specific knowledge.
5787 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]5788</p>
5789<h5>Semantics:</h5>
5790<p>
5791 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5792 dependent code, turning it into a function. A pointer to this function is
5793 returned, but needs to be bitcast to an
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5794 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5795 before being called. The new function's signature is the same as that of
5796 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
5797 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
5798 of pointer type. Calling the new function is equivalent to calling
5799 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
5800 missing <tt>nest</tt> argument. If, after calling
5801 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
5802 modified, then the effect of any later call to the returned function pointer is
5803 undefined.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5804</p>
5805</div>
5806
5807<!-- ======================================================================= -->
5808<div class="doc_subsection">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]5809 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
5810</div>
5811
5812<div class="doc_text">
5813<p>
5814 These intrinsic functions expand the "universal IR" of LLVM to represent
5815 hardware constructs for atomic operations and memory synchronization. This
5816 provides an interface to the hardware, not an interface to the programmer. It
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5817 is aimed at a low enough level to allow any programming models or APIs
5818 (Application Programming Interfaces) which
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]5819 need atomic behaviors to map cleanly onto it. It is also modeled primarily on
5820 hardware behavior. Just as hardware provides a "universal IR" for source
5821 languages, it also provides a starting point for developing a "universal"
5822 atomic operation and synchronization IR.
5823</p>
5824<p>
5825 These do <em>not</em> form an API such as high-level threading libraries,
5826 software transaction memory systems, atomic primitives, and intrinsic
5827 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
5828 application libraries. The hardware interface provided by LLVM should allow
5829 a clean implementation of all of these APIs and parallel programming models.
5830 No one model or paradigm should be selected above others unless the hardware
5831 itself ubiquitously does so.
5832
5833</p>
5834</div>
5835
5836<!-- _______________________________________________________________________ -->
5837<div class="doc_subsubsection">
5838 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
5839</div>
5840<div class="doc_text">
5841<h5>Syntax:</h5>
5842<pre>
5843declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;,
5844i1 &lt;device&gt; )
5845
5846</pre>
5847<h5>Overview:</h5>
5848<p>
5849 The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
5850 specific pairs of memory access types.
5851</p>
5852<h5>Arguments:</h5>
5853<p>
5854 The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
5855 The first four arguments enables a specific barrier as listed below. The fith
5856 argument specifies that the barrier applies to io or device or uncached memory.
5857
5858</p>
5859 <ul>
5860 <li><tt>ll</tt>: load-load barrier</li>
5861 <li><tt>ls</tt>: load-store barrier</li>
5862 <li><tt>sl</tt>: store-load barrier</li>
5863 <li><tt>ss</tt>: store-store barrier</li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5864 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]5865 </ul>
5866<h5>Semantics:</h5>
5867<p>
5868 This intrinsic causes the system to enforce some ordering constraints upon
5869 the loads and stores of the program. This barrier does not indicate
5870 <em>when</em> any events will occur, it only enforces an <em>order</em> in
5871 which they occur. For any of the specified pairs of load and store operations
5872 (f.ex. load-load, or store-load), all of the first operations preceding the
5873 barrier will complete before any of the second operations succeeding the
5874 barrier begin. Specifically the semantics for each pairing is as follows:
5875</p>
5876 <ul>
5877 <li><tt>ll</tt>: All loads before the barrier must complete before any load
5878 after the barrier begins.</li>
5879
5880 <li><tt>ls</tt>: All loads before the barrier must complete before any
5881 store after the barrier begins.</li>
5882 <li><tt>ss</tt>: All stores before the barrier must complete before any
5883 store after the barrier begins.</li>
5884 <li><tt>sl</tt>: All stores before the barrier must complete before any
5885 load after the barrier begins.</li>
5886 </ul>
5887<p>
5888 These semantics are applied with a logical "and" behavior when more than one
5889 is enabled in a single memory barrier intrinsic.
5890</p>
5891<p>
5892 Backends may implement stronger barriers than those requested when they do not
5893 support as fine grained a barrier as requested. Some architectures do not
5894 need all types of barriers and on such architectures, these become noops.
5895</p>
5896<h5>Example:</h5>
5897<pre>
5898%ptr = malloc i32
5899 store i32 4, %ptr
5900
5901%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
5902 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
5903 <i>; guarantee the above finishes</i>
5904 store i32 8, %ptr <i>; before this begins</i>
5905</pre>
5906</div>
5907
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5908<!-- _______________________________________________________________________ -->
5909<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]5910 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5911</div>
5912<div class="doc_text">
5913<h5>Syntax:</h5>
5914<p>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]5915 This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
5916 any integer bit width and for different address spaces. Not all targets
5917 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5918
5919<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]5920declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
5921declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
5922declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
5923declare 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]5924
5925</pre>
5926<h5>Overview:</h5>
5927<p>
5928 This loads a value in memory and compares it to a given value. If they are
5929 equal, it stores a new value into the memory.
5930</p>
5931<h5>Arguments:</h5>
5932<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]5933 The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5934 well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
5935 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
5936 this integer type. While any bit width integer may be used, targets may only
5937 lower representations they support in hardware.
5938
5939</p>
5940<h5>Semantics:</h5>
5941<p>
5942 This entire intrinsic must be executed atomically. It first loads the value
5943 in memory pointed to by <tt>ptr</tt> and compares it with the value
5944 <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
5945 loaded value is yielded in all cases. This provides the equivalent of an
5946 atomic compare-and-swap operation within the SSA framework.
5947</p>
5948<h5>Examples:</h5>
5949
5950<pre>
5951%ptr = malloc i32
5952 store i32 4, %ptr
5953
5954%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]5955%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5956 <i>; yields {i32}:result1 = 4</i>
5957%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
5958%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
5959
5960%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]5961%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5962 <i>; yields {i32}:result2 = 8</i>
5963%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
5964
5965%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
5966</pre>
5967</div>
5968
5969<!-- _______________________________________________________________________ -->
5970<div class="doc_subsubsection">
5971 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
5972</div>
5973<div class="doc_text">
5974<h5>Syntax:</h5>
5975
5976<p>
5977 This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
5978 integer bit width. Not all targets support all bit widths however.</p>
5979<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]5980declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
5981declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
5982declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
5983declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5984
5985</pre>
5986<h5>Overview:</h5>
5987<p>
5988 This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
5989 the value from memory. It then stores the value in <tt>val</tt> in the memory
5990 at <tt>ptr</tt>.
5991</p>
5992<h5>Arguments:</h5>
5993
5994<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]5995 The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5996 <tt>val</tt> argument and the result must be integers of the same bit width.
5997 The first argument, <tt>ptr</tt>, must be a pointer to a value of this
5998 integer type. The targets may only lower integer representations they
5999 support.
6000</p>
6001<h5>Semantics:</h5>
6002<p>
6003 This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6004 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6005 equivalent of an atomic swap operation within the SSA framework.
6006
6007</p>
6008<h5>Examples:</h5>
6009<pre>
6010%ptr = malloc i32
6011 store i32 4, %ptr
6012
6013%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6014%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6015 <i>; yields {i32}:result1 = 4</i>
6016%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6017%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6018
6019%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6020%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6021 <i>; yields {i32}:result2 = 8</i>
6022
6023%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6024%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6025</pre>
6026</div>
6027
6028<!-- _______________________________________________________________________ -->
6029<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6030 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6031
6032</div>
6033<div class="doc_text">
6034<h5>Syntax:</h5>
6035<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6036 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]6037 integer bit width. Not all targets support all bit widths however.</p>
6038<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6039declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6040declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6041declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6042declare 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]6043
6044</pre>
6045<h5>Overview:</h5>
6046<p>
6047 This intrinsic adds <tt>delta</tt> to the value stored in memory at
6048 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6049</p>
6050<h5>Arguments:</h5>
6051<p>
6052
6053 The intrinsic takes two arguments, the first a pointer to an integer value
6054 and the second an integer value. The result is also an integer value. These
6055 integer types can have any bit width, but they must all have the same bit
6056 width. The targets may only lower integer representations they support.
6057</p>
6058<h5>Semantics:</h5>
6059<p>
6060 This intrinsic does a series of operations atomically. It first loads the
6061 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6062 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6063</p>
6064
6065<h5>Examples:</h5>
6066<pre>
6067%ptr = malloc i32
6068 store i32 4, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6069%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6070 <i>; yields {i32}:result1 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6071%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6072 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6073%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6074 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6075%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6076</pre>
6077</div>
6078
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6079<!-- _______________________________________________________________________ -->
6080<div class="doc_subsubsection">
6081 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6082
6083</div>
6084<div class="doc_text">
6085<h5>Syntax:</h5>
6086<p>
6087 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]6088 any integer bit width and for different address spaces. Not all targets
6089 support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6090<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6091declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6092declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6093declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6094declare 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]6095
6096</pre>
6097<h5>Overview:</h5>
6098<p>
6099 This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6100 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6101</p>
6102<h5>Arguments:</h5>
6103<p>
6104
6105 The intrinsic takes two arguments, the first a pointer to an integer value
6106 and the second an integer value. The result is also an integer value. These
6107 integer types can have any bit width, but they must all have the same bit
6108 width. The targets may only lower integer representations they support.
6109</p>
6110<h5>Semantics:</h5>
6111<p>
6112 This intrinsic does a series of operations atomically. It first loads the
6113 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6114 result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6115</p>
6116
6117<h5>Examples:</h5>
6118<pre>
6119%ptr = malloc i32
6120 store i32 8, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6121%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6122 <i>; yields {i32}:result1 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6123%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6124 <i>; yields {i32}:result2 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6125%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6126 <i>; yields {i32}:result3 = 2</i>
6127%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6128</pre>
6129</div>
6130
6131<!-- _______________________________________________________________________ -->
6132<div class="doc_subsubsection">
6133 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6134 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6135 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6136 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
6137
6138</div>
6139<div class="doc_text">
6140<h5>Syntax:</h5>
6141<p>
6142 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
6143 <tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6144 <tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
6145 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6146<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6147declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6148declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6149declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6150declare 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]6151
6152</pre>
6153
6154<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6155declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6156declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6157declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6158declare 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]6159
6160</pre>
6161
6162<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6163declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6164declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6165declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6166declare 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]6167
6168</pre>
6169
6170<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6171declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6172declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6173declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6174declare 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]6175
6176</pre>
6177<h5>Overview:</h5>
6178<p>
6179 These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6180 the value stored in memory at <tt>ptr</tt>. It yields the original value
6181 at <tt>ptr</tt>.
6182</p>
6183<h5>Arguments:</h5>
6184<p>
6185
6186 These intrinsics take two arguments, the first a pointer to an integer value
6187 and the second an integer value. The result is also an integer value. These
6188 integer types can have any bit width, but they must all have the same bit
6189 width. The targets may only lower integer representations they support.
6190</p>
6191<h5>Semantics:</h5>
6192<p>
6193 These intrinsics does a series of operations atomically. They first load the
6194 value stored at <tt>ptr</tt>. They then do the bitwise operation
6195 <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
6196 value stored at <tt>ptr</tt>.
6197</p>
6198
6199<h5>Examples:</h5>
6200<pre>
6201%ptr = malloc i32
6202 store i32 0x0F0F, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6203%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6204 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6205%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6206 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6207%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6208 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6209%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6210 <i>; yields {i32}:result3 = FF</i>
6211%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6212</pre>
6213</div>
6214
6215
6216<!-- _______________________________________________________________________ -->
6217<div class="doc_subsubsection">
6218 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6219 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6220 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6221 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
6222
6223</div>
6224<div class="doc_text">
6225<h5>Syntax:</h5>
6226<p>
6227 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6228 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6229 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6230 address spaces. Not all targets
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6231 support all bit widths however.</p>
6232<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6233declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6234declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6235declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6236declare 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]6237
6238</pre>
6239
6240<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6241declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6242declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6243declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6244declare 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]6245
6246</pre>
6247
6248<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6249declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6250declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6251declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6252declare 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]6253
6254</pre>
6255
6256<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6257declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6258declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6259declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6260declare 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]6261
6262</pre>
6263<h5>Overview:</h5>
6264<p>
6265 These intrinsics takes the signed or unsigned minimum or maximum of
6266 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6267 original value at <tt>ptr</tt>.
6268</p>
6269<h5>Arguments:</h5>
6270<p>
6271
6272 These intrinsics take two arguments, the first a pointer to an integer value
6273 and the second an integer value. The result is also an integer value. These
6274 integer types can have any bit width, but they must all have the same bit
6275 width. The targets may only lower integer representations they support.
6276</p>
6277<h5>Semantics:</h5>
6278<p>
6279 These intrinsics does a series of operations atomically. They first load the
6280 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
6281 <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
6282 the original value stored at <tt>ptr</tt>.
6283</p>
6284
6285<h5>Examples:</h5>
6286<pre>
6287%ptr = malloc i32
6288 store i32 7, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6289%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6290 <i>; yields {i32}:result0 = 7</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6291%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6292 <i>; yields {i32}:result1 = -2</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6293%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6294 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6295%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6296 <i>; yields {i32}:result3 = 8</i>
6297%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6298</pre>
6299</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6300
6301<!-- ======================================================================= -->
6302<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6303 <a name="int_general">General Intrinsics</a>
6304</div>
6305
6306<div class="doc_text">
6307<p> This class of intrinsics is designed to be generic and has
6308no specific purpose. </p>
6309</div>
6310
6311<!-- _______________________________________________________________________ -->
6312<div class="doc_subsubsection">
6313 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6314</div>
6315
6316<div class="doc_text">
6317
6318<h5>Syntax:</h5>
6319<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]6320 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]6321</pre>
6322
6323<h5>Overview:</h5>
6324
6325<p>
6326The '<tt>llvm.var.annotation</tt>' intrinsic
6327</p>
6328
6329<h5>Arguments:</h5>
6330
6331<p>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]6332The first argument is a pointer to a value, the second is a pointer to a
6333global string, the third is a pointer to a global string which is the source
6334file name, and the last argument is the line number.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6335</p>
6336
6337<h5>Semantics:</h5>
6338
6339<p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6340This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6341This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6342annotations. These have no other defined use, they are ignored by code
6343generation and optimization.
6344</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6345</div>
6346
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6347<!-- _______________________________________________________________________ -->
6348<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]6349 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6350</div>
6351
6352<div class="doc_text">
6353
6354<h5>Syntax:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6355<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6356any integer bit width.
6357</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6358<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]6359 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6360 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6361 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6362 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6363 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]6364</pre>
6365
6366<h5>Overview:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6367
6368<p>
6369The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6370</p>
6371
6372<h5>Arguments:</h5>
6373
6374<p>
6375The first argument is an integer value (result of some expression),
6376the second is a pointer to a global string, the third is a pointer to a global
6377string which is the source file name, and the last argument is the line number.
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6378It returns the value of the first argument.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6379</p>
6380
6381<h5>Semantics:</h5>
6382
6383<p>
6384This intrinsic allows annotations to be put on arbitrary expressions
6385with arbitrary strings. This can be useful for special purpose optimizations
6386that want to look for these annotations. These have no other defined use, they
6387are ignored by code generation and optimization.
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6388</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6389</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6390
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6391<!-- _______________________________________________________________________ -->
6392<div class="doc_subsubsection">
6393 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6394</div>
6395
6396<div class="doc_text">
6397
6398<h5>Syntax:</h5>
6399<pre>
6400 declare void @llvm.trap()
6401</pre>
6402
6403<h5>Overview:</h5>
6404
6405<p>
6406The '<tt>llvm.trap</tt>' intrinsic
6407</p>
6408
6409<h5>Arguments:</h5>
6410
6411<p>
6412None
6413</p>
6414
6415<h5>Semantics:</h5>
6416
6417<p>
6418This intrinsics is lowered to the target dependent trap instruction. If the
6419target does not have a trap instruction, this intrinsic will be lowered to the
6420call of the abort() function.
6421</p>
6422</div>
6423
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame^]6424<!-- _______________________________________________________________________ -->
6425<div class="doc_subsubsection">
6426 <a name="int_ssp">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
6427</div>
6428<div class="doc_text">
6429<h5>Syntax:</h5>
6430<pre>
6431declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
6432
6433</pre>
6434<h5>Overview:</h5>
6435<p>
6436 The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
6437 it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
6438 it is placed on the stack before local variables.
6439</p>
6440<h5>Arguments:</h5>
6441<p>
6442 The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
6443 first argument is the value loaded from the stack guard
6444 <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
6445 has enough space to hold the value of the guard.
6446</p>
6447<h5>Semantics:</h5>
6448<p>
6449 This intrinsic causes the prologue/epilogue inserter to force the position of
6450 the <tt>AllocaInst</tt> stack slot to be before local variables on the
6451 stack. This is to ensure that if a local variable on the stack is overwritten,
6452 it will destroy the value of the guard. When the function exits, the guard on
6453 the stack is checked against the original guard. If they're different, then
6454 the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
6455</p>
6456</div>
6457
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6458<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6459<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6460<address>
6461 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
6462 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
6463 <a href="http://validator.w3.org/check/referer"><img
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]6464 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6465
6466 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]6467 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6468 Last modified: $Date$
6469</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]6470
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6471</body>
6472</html>