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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / f8b94812a15515efd5a9ddf422358bad5ebb4105 / . / 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>
Anton Korobeynikovc6c98af2007-04-29 18:02:48 +0000[diff] [blame]27 <li><a href="#aliasstructure">Aliases</a>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]28 <li><a href="#paramattrs">Parameter Attributes</a></li>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]29 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]30 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]31 <li><a href="#datalayout">Data Layout</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]32 </ol>
33 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]34 <li><a href="#typesystem">Type System</a>
35 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]36 <li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]37 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]38 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]39 <li><a href="#t_floating">Floating Point Types</a></li>
40 <li><a href="#t_void">Void Type</a></li>
41 <li><a href="#t_label">Label Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]42 </ol>
43 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]44 <li><a href="#t_derived">Derived Types</a>
45 <ol>
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]46 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]47 <li><a href="#t_array">Array Type</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]48 <li><a href="#t_function">Function Type</a></li>
49 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]50 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]51 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]52 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]53 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]54 </ol>
55 </li>
56 </ol>
57 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]58 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]59 <ol>
60 <li><a href="#simpleconstants">Simple Constants</a>
61 <li><a href="#aggregateconstants">Aggregate Constants</a>
62 <li><a href="#globalconstants">Global Variable and Function Addresses</a>
63 <li><a href="#undefvalues">Undefined Values</a>
64 <li><a href="#constantexprs">Constant Expressions</a>
65 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]66 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]67 <li><a href="#othervalues">Other Values</a>
68 <ol>
69 <li><a href="#inlineasm">Inline Assembler Expressions</a>
70 </ol>
71 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]72 <li><a href="#instref">Instruction Reference</a>
73 <ol>
74 <li><a href="#terminators">Terminator Instructions</a>
75 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]76 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
77 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]78 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
79 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]80 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]81 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]82 </ol>
83 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]84 <li><a href="#binaryops">Binary Operations</a>
85 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]86 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
87 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
88 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]89 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
90 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
91 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]92 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
93 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
94 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]95 </ol>
96 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]97 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
98 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]99 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
100 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
101 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]102 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]103 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]104 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]105 </ol>
106 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]107 <li><a href="#vectorops">Vector Operations</a>
108 <ol>
109 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
110 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
111 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]112 </ol>
113 </li>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]114 <li><a href="#aggregateops">Aggregate Operations</a>
115 <ol>
116 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
117 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
118 </ol>
119 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]120 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]121 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]122 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
123 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
124 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]125 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
126 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
127 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]128 </ol>
129 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]130 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]131 <ol>
132 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
133 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
134 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
135 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
136 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]137 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
138 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
139 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
140 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]141 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
142 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]143 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]144 </ol>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]145 <li><a href="#otherops">Other Operations</a>
146 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]147 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
148 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]149 <li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
150 <li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]151 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]152 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]153 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]154 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]155 <li><a href="#i_getresult">'<tt>getresult</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]156 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]157 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]158 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]159 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]160 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]161 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]162 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
163 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]164 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
165 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
166 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]167 </ol>
168 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]169 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
170 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]171 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
172 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
173 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]174 </ol>
175 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]176 <li><a href="#int_codegen">Code Generator Intrinsics</a>
177 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]178 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
179 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
180 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
181 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
182 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
183 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
184 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]185 </ol>
186 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]187 <li><a href="#int_libc">Standard C Library Intrinsics</a>
188 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]189 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
190 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
191 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
192 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
193 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]194 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
195 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
196 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]197 </ol>
198 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]199 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]200 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]201 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]202 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
203 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
204 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]205 <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
206 <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]207 </ol>
208 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]209 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]210 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]211 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]212 <ol>
213 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]214 </ol>
215 </li>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]216 <li><a href="#int_atomics">Atomic intrinsics</a>
217 <ol>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]218 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]219 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]220 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]221 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
222 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
223 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
224 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
225 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
226 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
227 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
228 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
229 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
230 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]231 </ol>
232 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]233 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]234 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]235 <li><a href="#int_var_annotation">
Tanya Lattner91d0b882007-09-22 00:01:26 +0000[diff] [blame]236 <tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]237 <li><a href="#int_annotation">
Tanya Lattner91d0b882007-09-22 00:01:26 +0000[diff] [blame]238 <tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]239 <li><a href="#int_trap">
240 <tt>llvm.trap</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]241 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]242 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]243 </ol>
244 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]245</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]246
247<div class="doc_author">
248 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
249 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]250</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]251
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]252<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]253<div class="doc_section"> <a name="abstract">Abstract </a></div>
254<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]255
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]256<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]257<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling837f39b2008-08-05 22:29:16 +0000[diff] [blame]258LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]259type safety, low-level operations, flexibility, and the capability of
260representing 'all' high-level languages cleanly. It is the common code
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]261representation used throughout all phases of the LLVM compilation
262strategy.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]263</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]264
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]265<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]266<div class="doc_section"> <a name="introduction">Introduction</a> </div>
267<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]268
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]269<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]270
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]271<p>The LLVM code representation is designed to be used in three
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]272different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]273representation (suitable for fast loading by a Just-In-Time compiler),
274and as a human readable assembly language representation. This allows
275LLVM to provide a powerful intermediate representation for efficient
276compiler transformations and analysis, while providing a natural means
277to debug and visualize the transformations. The three different forms
278of LLVM are all equivalent. This document describes the human readable
279representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]280
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]281<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]282while being expressive, typed, and extensible at the same time. It
283aims to be a "universal IR" of sorts, by being at a low enough level
284that high-level ideas may be cleanly mapped to it (similar to how
285microprocessors are "universal IR's", allowing many source languages to
286be mapped to them). By providing type information, LLVM can be used as
287the target of optimizations: for example, through pointer analysis, it
288can be proven that a C automatic variable is never accessed outside of
289the current function... allowing it to be promoted to a simple SSA
290value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]291
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]292</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]293
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]294<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]295<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]296
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]297<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]298
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]299<p>It is important to note that this document describes 'well formed'
300LLVM assembly language. There is a difference between what the parser
301accepts and what is considered 'well formed'. For example, the
302following instruction is syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]303
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]304<div class="doc_code">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]305<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]306%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]307</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]308</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]309
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]310<p>...because the definition of <tt>%x</tt> does not dominate all of
311its uses. The LLVM infrastructure provides a verification pass that may
312be used to verify that an LLVM module is well formed. This pass is
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]313automatically run by the parser after parsing input assembly and by
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]314the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]315by the verifier pass indicate bugs in transformation passes or input to
316the parser.</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]317</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]318
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]319<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]320
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]321<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]322<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]323<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]324
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]325<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]326
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]327 <p>LLVM identifiers come in two basic types: global and local. Global
328 identifiers (functions, global variables) begin with the @ character. Local
329 identifiers (register names, types) begin with the % character. Additionally,
330 there are three different formats for identifiers, for different purposes:
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]331
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]332<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]333 <li>Named values are represented as a string of characters with their prefix.
334 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
335 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]336 Identifiers which require other characters in their names can be surrounded
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]337 with quotes. In this way, anything except a <tt>&quot;</tt> character can
338 be used in a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]339
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]340 <li>Unnamed values are represented as an unsigned numeric value with their
341 prefix. For example, %12, @2, %44.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]342
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]343 <li>Constants, which are described in a <a href="#constants">section about
344 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]345</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]346
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]347<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]348don't need to worry about name clashes with reserved words, and the set of
349reserved words may be expanded in the future without penalty. Additionally,
350unnamed identifiers allow a compiler to quickly come up with a temporary
351variable without having to avoid symbol table conflicts.</p>
352
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]353<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]354languages. There are keywords for different opcodes
355('<tt><a href="#i_add">add</a></tt>',
356 '<tt><a href="#i_bitcast">bitcast</a></tt>',
357 '<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]358href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]359and others. These reserved words cannot conflict with variable names, because
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]360none of them start with a prefix character ('%' or '@').</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]361
362<p>Here is an example of LLVM code to multiply the integer variable
363'<tt>%X</tt>' by 8:</p>
364
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]365<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]366
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]367<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]368<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]369%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]370</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]371</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]372
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]373<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]374
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]375<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]376<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]377%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]378</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]379</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]380
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]381<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]382
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]383<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]384<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]385<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
386<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
387%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]388</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]389</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]390
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]391<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
392important lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]393
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]394<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]395
396 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
397 line.</li>
398
399 <li>Unnamed temporaries are created when the result of a computation is not
400 assigned to a named value.</li>
401
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]402 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]403
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]404</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]405
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]406<p>...and it also shows a convention that we follow in this document. When
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]407demonstrating instructions, we will follow an instruction with a comment that
408defines the type and name of value produced. Comments are shown in italic
409text.</p>
410
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]411</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]412
413<!-- *********************************************************************** -->
414<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
415<!-- *********************************************************************** -->
416
417<!-- ======================================================================= -->
418<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
419</div>
420
421<div class="doc_text">
422
423<p>LLVM programs are composed of "Module"s, each of which is a
424translation unit of the input programs. Each module consists of
425functions, global variables, and symbol table entries. Modules may be
426combined together with the LLVM linker, which merges function (and
427global variable) definitions, resolves forward declarations, and merges
428symbol table entries. Here is an example of the "hello world" module:</p>
429
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]430<div class="doc_code">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]431<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]432<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
433 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]434
435<i>; External declaration of the puts function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]436<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]437
438<i>; Definition of main function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]439define i32 @main() { <i>; i32()* </i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]440 <i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]441 %cast210 = <a
Chris Lattner6c0955b2007-06-12 17:01:15 +0000[diff] [blame]442 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]443
444 <i>; Call puts function to write out the string to stdout...</i>
445 <a
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]446 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]447 <a
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]448 href="#i_ret">ret</a> i32 0<br>}<br>
449</pre>
450</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]451
452<p>This example is made up of a <a href="#globalvars">global variable</a>
453named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
454function, and a <a href="#functionstructure">function definition</a>
455for "<tt>main</tt>".</p>
456
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]457<p>In general, a module is made up of a list of global values,
458where both functions and global variables are global values. Global values are
459represented by a pointer to a memory location (in this case, a pointer to an
460array of char, and a pointer to a function), and have one of the following <a
461href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]462
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]463</div>
464
465<!-- ======================================================================= -->
466<div class="doc_subsection">
467 <a name="linkage">Linkage Types</a>
468</div>
469
470<div class="doc_text">
471
472<p>
473All Global Variables and Functions have one of the following types of linkage:
474</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]475
476<dl>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]477
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]478 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]479
480 <dd>Global values with internal linkage are only directly accessible by
481 objects in the current module. In particular, linking code into a module with
482 an internal global value may cause the internal to be renamed as necessary to
483 avoid collisions. Because the symbol is internal to the module, all
484 references can be updated. This corresponds to the notion of the
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]485 '<tt>static</tt>' keyword in C.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]486 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]487
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]488 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]489
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]490 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
491 the same name when linkage occurs. This is typically used to implement
492 inline functions, templates, or other code which must be generated in each
493 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
494 allowed to be discarded.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]495 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]496
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]497 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
498
499 <dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
500 linkage, except that unreferenced <tt>common</tt> globals may not be
501 discarded. This is used for globals that may be emitted in multiple
502 translation units, but that are not guaranteed to be emitted into every
503 translation unit that uses them. One example of this is tentative
504 definitions in C, such as "<tt>int X;</tt>" at global scope.
505 </dd>
506
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]507 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]508
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]509 <dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
510 that some targets may choose to emit different assembly sequences for them
511 for target-dependent reasons. This is used for globals that are declared
512 "weak" in C source code.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]513 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]514
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]515 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]516
517 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
518 pointer to array type. When two global variables with appending linkage are
519 linked together, the two global arrays are appended together. This is the
520 LLVM, typesafe, equivalent of having the system linker append together
521 "sections" with identical names when .o files are linked.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]522 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]523
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]524 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]525 <dd>The semantics of this linkage follow the ELF object file model: the
526 symbol is weak until linked, if not linked, the symbol becomes null instead
527 of being an undefined reference.
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]528 </dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]529
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]530 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]531
532 <dd>If none of the above identifiers are used, the global is externally
533 visible, meaning that it participates in linkage and can be used to resolve
534 external symbol references.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]535 </dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]536</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]537
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]538 <p>
539 The next two types of linkage are targeted for Microsoft Windows platform
540 only. They are designed to support importing (exporting) symbols from (to)
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]541 DLLs (Dynamic Link Libraries).
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]542 </p>
543
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]544 <dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]545 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
546
547 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
548 or variable via a global pointer to a pointer that is set up by the DLL
549 exporting the symbol. On Microsoft Windows targets, the pointer name is
550 formed by combining <code>_imp__</code> and the function or variable name.
551 </dd>
552
553 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
554
555 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
556 pointer to a pointer in a DLL, so that it can be referenced with the
557 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
558 name is formed by combining <code>_imp__</code> and the function or variable
559 name.
560 </dd>
561
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]562</dl>
563
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]564<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]565variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
566variable and was linked with this one, one of the two would be renamed,
567preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
568external (i.e., lacking any linkage declarations), they are accessible
Reid Spencerac8d2762007-01-05 00:59:10 +0000[diff] [blame]569outside of the current module.</p>
570<p>It is illegal for a function <i>declaration</i>
571to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]572or <tt>extern_weak</tt>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]573<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
574linkages.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]575</div>
576
577<!-- ======================================================================= -->
578<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]579 <a name="callingconv">Calling Conventions</a>
580</div>
581
582<div class="doc_text">
583
584<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
585and <a href="#i_invoke">invokes</a> can all have an optional calling convention
586specified for the call. The calling convention of any pair of dynamic
587caller/callee must match, or the behavior of the program is undefined. The
588following calling conventions are supported by LLVM, and more may be added in
589the future:</p>
590
591<dl>
592 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
593
594 <dd>This calling convention (the default if no other calling convention is
595 specified) matches the target C calling conventions. This calling convention
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]596 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencerc28d2bc2006-12-31 21:30:18 +0000[diff] [blame]597 prototype and implemented declaration of the function (as does normal C).
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]598 </dd>
599
600 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
601
602 <dd>This calling convention attempts to make calls as fast as possible
603 (e.g. by passing things in registers). This calling convention allows the
604 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]605 without having to conform to an externally specified ABI (Application Binary
606 Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer9097d142008-05-14 09:17:12 +0000[diff] [blame]607 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
608 supported. This calling convention does not support varargs and requires the
609 prototype of all callees to exactly match the prototype of the function
610 definition.
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]611 </dd>
612
613 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
614
615 <dd>This calling convention attempts to make code in the caller as efficient
616 as possible under the assumption that the call is not commonly executed. As
617 such, these calls often preserve all registers so that the call does not break
618 any live ranges in the caller side. This calling convention does not support
619 varargs and requires the prototype of all callees to exactly match the
620 prototype of the function definition.
621 </dd>
622
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]623 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]624
625 <dd>Any calling convention may be specified by number, allowing
626 target-specific calling conventions to be used. Target specific calling
627 conventions start at 64.
628 </dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]629</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]630
631<p>More calling conventions can be added/defined on an as-needed basis, to
632support pascal conventions or any other well-known target-independent
633convention.</p>
634
635</div>
636
637<!-- ======================================================================= -->
638<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]639 <a name="visibility">Visibility Styles</a>
640</div>
641
642<div class="doc_text">
643
644<p>
645All Global Variables and Functions have one of the following visibility styles:
646</p>
647
648<dl>
649 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
650
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]651 <dd>On targets that use the ELF object file format, default visibility means
652 that the declaration is visible to other
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]653 modules and, in shared libraries, means that the declared entity may be
654 overridden. On Darwin, default visibility means that the declaration is
655 visible to other modules. Default visibility corresponds to "external
656 linkage" in the language.
657 </dd>
658
659 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
660
661 <dd>Two declarations of an object with hidden visibility refer to the same
662 object if they are in the same shared object. Usually, hidden visibility
663 indicates that the symbol will not be placed into the dynamic symbol table,
664 so no other module (executable or shared library) can reference it
665 directly.
666 </dd>
667
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]668 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
669
670 <dd>On ELF, protected visibility indicates that the symbol will be placed in
671 the dynamic symbol table, but that references within the defining module will
672 bind to the local symbol. That is, the symbol cannot be overridden by another
673 module.
674 </dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]675</dl>
676
677</div>
678
679<!-- ======================================================================= -->
680<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]681 <a name="globalvars">Global Variables</a>
682</div>
683
684<div class="doc_text">
685
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]686<p>Global variables define regions of memory allocated at compilation time
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]687instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]688an explicit section to be placed in, and may have an optional explicit alignment
689specified. A variable may be defined as "thread_local", which means that it
690will not be shared by threads (each thread will have a separated copy of the
691variable). A variable may be defined as a global "constant," which indicates
692that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]693optimization, allowing the global data to be placed in the read-only section of
694an executable, etc). Note that variables that need runtime initialization
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]695cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]696
697<p>
698LLVM explicitly allows <em>declarations</em> of global variables to be marked
699constant, even if the final definition of the global is not. This capability
700can be used to enable slightly better optimization of the program, but requires
701the language definition to guarantee that optimizations based on the
702'constantness' are valid for the translation units that do not include the
703definition.
704</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]705
706<p>As SSA values, global variables define pointer values that are in
707scope (i.e. they dominate) all basic blocks in the program. Global
708variables always define a pointer to their "content" type because they
709describe a region of memory, and all memory objects in LLVM are
710accessed through pointers.</p>
711
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]712<p>A global variable may be declared to reside in a target-specifc numbered
713address space. For targets that support them, address spaces may affect how
714optimizations are performed and/or what target instructions are used to access
Christopher Lambd49e18d2007-12-12 08:44:39 +0000[diff] [blame]715the variable. The default address space is zero. The address space qualifier
716must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]717
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]718<p>LLVM allows an explicit section to be specified for globals. If the target
719supports it, it will emit globals to the section specified.</p>
720
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]721<p>An explicit alignment may be specified for a global. If not present, or if
722the alignment is set to zero, the alignment of the global is set by the target
723to whatever it feels convenient. If an explicit alignment is specified, the
724global is forced to have at least that much alignment. All alignments must be
725a power of 2.</p>
726
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]727<p>For example, the following defines a global in a numbered address space with
728an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]729
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]730<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]731<pre>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]732@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]733</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]734</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]735
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]736</div>
737
738
739<!-- ======================================================================= -->
740<div class="doc_subsection">
741 <a name="functionstructure">Functions</a>
742</div>
743
744<div class="doc_text">
745
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]746<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
747an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]748<a href="#visibility">visibility style</a>, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]749<a href="#callingconv">calling convention</a>, a return type, an optional
750<a href="#paramattrs">parameter attribute</a> for the return type, a function
751name, a (possibly empty) argument list (each with optional
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]752<a href="#paramattrs">parameter attributes</a>), an optional section, an
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame^]753optional alignment, an optional <a href="#gc">garbage collector name</a>,
754an optional <a href="#notes">function notes</a>, an
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]755opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]756
757LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
758optional <a href="#linkage">linkage type</a>, an optional
759<a href="#visibility">visibility style</a>, an optional
760<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]761<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]762name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksene754abe2007-12-10 03:30:21 +0000[diff] [blame]763<a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]764
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]765<p>A function definition contains a list of basic blocks, forming the CFG
766(Control Flow Graph) for
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]767the function. Each basic block may optionally start with a label (giving the
768basic block a symbol table entry), contains a list of instructions, and ends
769with a <a href="#terminators">terminator</a> instruction (such as a branch or
770function return).</p>
771
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]772<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]773executed on entrance to the function, and it is not allowed to have predecessor
774basic blocks (i.e. there can not be any branches to the entry block of a
775function). Because the block can have no predecessors, it also cannot have any
776<a href="#i_phi">PHI nodes</a>.</p>
777
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]778<p>LLVM allows an explicit section to be specified for functions. If the target
779supports it, it will emit functions to the section specified.</p>
780
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]781<p>An explicit alignment may be specified for a function. If not present, or if
782the alignment is set to zero, the alignment of the function is set by the target
783to whatever it feels convenient. If an explicit alignment is specified, the
784function is forced to have at least that much alignment. All alignments must be
785a power of 2.</p>
786
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]787</div>
788
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]789
790<!-- ======================================================================= -->
791<div class="doc_subsection">
792 <a name="aliasstructure">Aliases</a>
793</div>
794<div class="doc_text">
795 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov726d45c2008-03-22 08:36:14 +0000[diff] [blame]796 function, global variable, another alias or bitcast of global value). Aliases
797 may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]798 optional <a href="#visibility">visibility style</a>.</p>
799
800 <h5>Syntax:</h5>
801
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]802<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]803<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]804@&lt;Name&gt; = [Linkage] [Visibility] alias &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]805</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]806</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]807
808</div>
809
810
811
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]812<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]813<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
814<div class="doc_text">
815 <p>The return type and each parameter of a function type may have a set of
816 <i>parameter attributes</i> associated with them. Parameter attributes are
817 used to communicate additional information about the result or parameters of
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]818 a function. Parameter attributes are considered to be part of the function,
819 not of the function type, so functions with different parameter attributes
820 can have the same function type.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]821
Reid Spencer950e9f82007-01-15 18:27:39 +0000[diff] [blame]822 <p>Parameter attributes are simple keywords that follow the type specified. If
823 multiple parameter attributes are needed, they are space separated. For
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]824 example:</p>
825
826<div class="doc_code">
827<pre>
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]828declare i32 @printf(i8* noalias , ...) nounwind
829declare i32 @atoi(i8*) nounwind readonly
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]830</pre>
831</div>
832
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]833 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
834 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]835
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]836 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]837 <dl>
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]838 <dt><tt>zeroext</tt></dt>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]839 <dd>This indicates that the parameter should be zero extended just before
840 a call to this function.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]841
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]842 <dt><tt>signext</tt></dt>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]843 <dd>This indicates that the parameter should be sign extended just before
844 a call to this function.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]845
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]846 <dt><tt>inreg</tt></dt>
847 <dd>This indicates that the parameter should be placed in register (if
Anton Korobeynikov66a8c8c2007-01-28 15:27:21 +0000[diff] [blame]848 possible) during assembling function call. Support for this attribute is
849 target-specific</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]850
851 <dt><tt>byval</tt></dt>
Chris Lattner0747baa2008-01-15 04:34:22 +0000[diff] [blame]852 <dd>This indicates that the pointer parameter should really be passed by
853 value to the function. The attribute implies that a hidden copy of the
854 pointee is made between the caller and the callee, so the callee is unable
Chris Lattnerebec6782008-08-05 18:21:08 +0000[diff] [blame]855 to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner0747baa2008-01-15 04:34:22 +0000[diff] [blame]856 pointer arguments. It is generally used to pass structs and arrays by
857 value, but is also valid on scalars (even though this is silly).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]858
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]859 <dt><tt>sret</tt></dt>
Duncan Sandse26dec62008-02-18 04:19:38 +0000[diff] [blame]860 <dd>This indicates that the pointer parameter specifies the address of a
861 structure that is the return value of the function in the source program.
Duncan Sandsb7f0c082008-03-17 12:17:41 +0000[diff] [blame]862 Loads and stores to the structure are assumed not to trap.
Duncan Sandse26dec62008-02-18 04:19:38 +0000[diff] [blame]863 May only be applied to the first parameter.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]864
Zhou Shengfebca342007-06-05 05:28:26 +0000[diff] [blame]865 <dt><tt>noalias</tt></dt>
Owen Anderson117bbd32008-02-18 04:09:01 +0000[diff] [blame]866 <dd>This indicates that the parameter does not alias any global or any other
867 parameter. The caller is responsible for ensuring that this is the case,
868 usually by placing the value in a stack allocation.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]869
Reid Spencer2dc52012007-03-22 02:18:56 +0000[diff] [blame]870 <dt><tt>noreturn</tt></dt>
871 <dd>This function attribute indicates that the function never returns. This
872 indicates to LLVM that every call to this function should be treated as if
873 an <tt>unreachable</tt> instruction immediately followed the call.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]874
Reid Spencer67606122007-03-22 02:02:11 +0000[diff] [blame]875 <dt><tt>nounwind</tt></dt>
Duncan Sandsb7f0c082008-03-17 12:17:41 +0000[diff] [blame]876 <dd>This function attribute indicates that no exceptions unwind out of the
877 function. Usually this is because the function makes no use of exceptions,
878 but it may also be that the function catches any exceptions thrown when
879 executing it.</dd>
880
Duncan Sands50f19f52007-07-27 19:57:41 +0000[diff] [blame]881 <dt><tt>nest</tt></dt>
Duncan Sands0789b8b2008-07-08 09:27:25 +0000[diff] [blame]882 <dd>This indicates that the pointer parameter can be excised using the
Duncan Sands50f19f52007-07-27 19:57:41 +0000[diff] [blame]883 <a href="#int_trampoline">trampoline intrinsics</a>.</dd>
Duncan Sandsed4a2f12007-11-22 20:23:04 +0000[diff] [blame]884 <dt><tt>readonly</tt></dt>
Duncan Sandsf04d5842007-11-14 21:14:02 +0000[diff] [blame]885 <dd>This function attribute indicates that the function has no side-effects
Duncan Sandsed4a2f12007-11-22 20:23:04 +0000[diff] [blame]886 except for producing a return value or throwing an exception. The value
887 returned must only depend on the function arguments and/or global variables.
888 It may use values obtained by dereferencing pointers.</dd>
889 <dt><tt>readnone</tt></dt>
890 <dd>A <tt>readnone</tt> function has the same restrictions as a <tt>readonly</tt>
Duncan Sandsf04d5842007-11-14 21:14:02 +0000[diff] [blame]891 function, but in addition it is not allowed to dereference any pointer arguments
892 or global variables.
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]893 </dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]894
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]895</div>
896
897<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]898<div class="doc_subsection">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]899 <a name="gc">Garbage Collector Names</a>
900</div>
901
902<div class="doc_text">
903<p>Each function may specify a garbage collector name, which is simply a
904string.</p>
905
906<div class="doc_code"><pre
907>define void @f() gc "name" { ...</pre></div>
908
909<p>The compiler declares the supported values of <i>name</i>. Specifying a
910collector which will cause the compiler to alter its output in order to support
911the named garbage collection algorithm.</p>
912</div>
913
914<!-- ======================================================================= -->
915<div class="doc_subsection">
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame^]916 <a name="notes">Function Notes</a>
917</div>
918
919<div class="doc_text">
920<p>Each function may specify function notes.</p>
921
922<div class="doc_code">
923<pre>define void @f() notes(inline=Always) { ... }</pre>
924<pre>define void @f() notes(inline=Always,opt-size) { ... }</pre>
925<pre>define void @f() notes(inline=Never,opt-size) { ... }</pre>
926<pre>define void @f() notes(opt-size) { ... }</pre>
927</div>
928
929<p>
930<li>inline=Always
931<p>
932This note requests inliner to inline this function irrespective of
933inlining size threshold for this function.
934</p></li>
935<li>inline=Never
936<p>
937This note requests inliner to never inline this function in any situation.
938This note may not be used together with inline=Always note.
939</p></li>
940<li>opt-size
941<p>
942This note suggests optimization passes and code generator passes to make
943choices that help reduce code size.
944</p></li>
945<p>
946The notes that are not documented here are considered invalid notes.
947</div>
948
949<!-- ======================================================================= -->
950<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]951 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]952</div>
953
954<div class="doc_text">
955<p>
956Modules may contain "module-level inline asm" blocks, which corresponds to the
957GCC "file scope inline asm" blocks. These blocks are internally concatenated by
958LLVM and treated as a single unit, but may be separated in the .ll file if
959desired. The syntax is very simple:
960</p>
961
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]962<div class="doc_code">
963<pre>
964module asm "inline asm code goes here"
965module asm "more can go here"
966</pre>
967</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]968
969<p>The strings can contain any character by escaping non-printable characters.
970 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
971 for the number.
972</p>
973
974<p>
975 The inline asm code is simply printed to the machine code .s file when
976 assembly code is generated.
977</p>
978</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]979
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]980<!-- ======================================================================= -->
981<div class="doc_subsection">
982 <a name="datalayout">Data Layout</a>
983</div>
984
985<div class="doc_text">
986<p>A module may specify a target specific data layout string that specifies how
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]987data is to be laid out in memory. The syntax for the data layout is simply:</p>
988<pre> target datalayout = "<i>layout specification</i>"</pre>
989<p>The <i>layout specification</i> consists of a list of specifications
990separated by the minus sign character ('-'). Each specification starts with a
991letter and may include other information after the letter to define some
992aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]993<dl>
994 <dt><tt>E</tt></dt>
995 <dd>Specifies that the target lays out data in big-endian form. That is, the
996 bits with the most significance have the lowest address location.</dd>
997 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]998 <dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]999 the bits with the least significance have the lowest address location.</dd>
1000 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1001 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
1002 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
1003 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
1004 too.</dd>
1005 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1006 <dd>This specifies the alignment for an integer type of a given bit
1007 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1008 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1009 <dd>This specifies the alignment for a vector type of a given bit
1010 <i>size</i>.</dd>
1011 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1012 <dd>This specifies the alignment for a floating point type of a given bit
1013 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1014 (double).</dd>
1015 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1016 <dd>This specifies the alignment for an aggregate type of a given bit
1017 <i>size</i>.</dd>
1018</dl>
1019<p>When constructing the data layout for a given target, LLVM starts with a
1020default set of specifications which are then (possibly) overriden by the
1021specifications in the <tt>datalayout</tt> keyword. The default specifications
1022are given in this list:</p>
1023<ul>
1024 <li><tt>E</tt> - big endian</li>
1025 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1026 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1027 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1028 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1029 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1030 <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]1031 alignment of 64-bits</li>
1032 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1033 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1034 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1035 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1036 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
1037</ul>
Chris Lattnerebec6782008-08-05 18:21:08 +0000[diff] [blame]1038<p>When LLVM is determining the alignment for a given type, it uses the
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1039following rules:
1040<ol>
1041 <li>If the type sought is an exact match for one of the specifications, that
1042 specification is used.</li>
1043 <li>If no match is found, and the type sought is an integer type, then the
1044 smallest integer type that is larger than the bitwidth of the sought type is
1045 used. If none of the specifications are larger than the bitwidth then the the
1046 largest integer type is used. For example, given the default specifications
1047 above, the i7 type will use the alignment of i8 (next largest) while both
1048 i65 and i256 will use the alignment of i64 (largest specified).</li>
1049 <li>If no match is found, and the type sought is a vector type, then the
1050 largest vector type that is smaller than the sought vector type will be used
1051 as a fall back. This happens because <128 x double> can be implemented in
1052 terms of 64 <2 x double>, for example.</li>
1053</ol>
1054</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1055
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1056<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1057<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1058<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1059
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1060<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1061
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1062<p>The LLVM type system is one of the most important features of the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1063intermediate representation. Being typed enables a number of
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1064optimizations to be performed on the intermediate representation directly,
1065without having to do
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1066extra analyses on the side before the transformation. A strong type
1067system makes it easier to read the generated code and enables novel
1068analyses and transformations that are not feasible to perform on normal
1069three address code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1070
1071</div>
1072
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1073<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1074<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1075Classifications</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1076<div class="doc_text">
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1077<p>The types fall into a few useful
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1078classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1079
1080<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1081 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1082 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1083 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1084 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1085 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1086 </tr>
1087 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1088 <td><a href="#t_floating">floating point</a></td>
1089 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1090 </tr>
1091 <tr>
1092 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1093 <td><a href="#t_integer">integer</a>,
1094 <a href="#t_floating">floating point</a>,
1095 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1096 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1097 <a href="#t_struct">structure</a>,
1098 <a href="#t_array">array</a>,
Dan Gohmanade5faa2008-05-23 22:50:26 +0000[diff] [blame]1099 <a href="#t_label">label</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1100 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1101 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1102 <tr>
1103 <td><a href="#t_primitive">primitive</a></td>
1104 <td><a href="#t_label">label</a>,
1105 <a href="#t_void">void</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1106 <a href="#t_floating">floating point</a>.</td>
1107 </tr>
1108 <tr>
1109 <td><a href="#t_derived">derived</a></td>
1110 <td><a href="#t_integer">integer</a>,
1111 <a href="#t_array">array</a>,
1112 <a href="#t_function">function</a>,
1113 <a href="#t_pointer">pointer</a>,
1114 <a href="#t_struct">structure</a>,
1115 <a href="#t_pstruct">packed structure</a>,
1116 <a href="#t_vector">vector</a>,
1117 <a href="#t_opaque">opaque</a>.
1118 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1119 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1120</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1121
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1122<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1123most important. Values of these types are the only ones which can be
1124produced by instructions, passed as arguments, or used as operands to
Dan Gohmanc4b49eb2008-05-23 21:53:15 +0000[diff] [blame]1125instructions.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1126</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1127
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1128<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1129<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1130
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1131<div class="doc_text">
1132<p>The primitive types are the fundamental building blocks of the LLVM
1133system.</p>
1134
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1135</div>
1136
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1137<!-- _______________________________________________________________________ -->
1138<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1139
1140<div class="doc_text">
1141 <table>
1142 <tbody>
1143 <tr><th>Type</th><th>Description</th></tr>
1144 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1145 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1146 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1147 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1148 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1149 </tbody>
1150 </table>
1151</div>
1152
1153<!-- _______________________________________________________________________ -->
1154<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1155
1156<div class="doc_text">
1157<h5>Overview:</h5>
1158<p>The void type does not represent any value and has no size.</p>
1159
1160<h5>Syntax:</h5>
1161
1162<pre>
1163 void
1164</pre>
1165</div>
1166
1167<!-- _______________________________________________________________________ -->
1168<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1169
1170<div class="doc_text">
1171<h5>Overview:</h5>
1172<p>The label type represents code labels.</p>
1173
1174<h5>Syntax:</h5>
1175
1176<pre>
1177 label
1178</pre>
1179</div>
1180
1181
1182<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1183<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1184
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1185<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1186
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1187<p>The real power in LLVM comes from the derived types in the system.
1188This is what allows a programmer to represent arrays, functions,
1189pointers, and other useful types. Note that these derived types may be
1190recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1191
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1192</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1193
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1194<!-- _______________________________________________________________________ -->
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1195<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1196
1197<div class="doc_text">
1198
1199<h5>Overview:</h5>
1200<p>The integer type is a very simple derived type that simply specifies an
1201arbitrary bit width for the integer type desired. Any bit width from 1 bit to
12022^23-1 (about 8 million) can be specified.</p>
1203
1204<h5>Syntax:</h5>
1205
1206<pre>
1207 iN
1208</pre>
1209
1210<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1211value.</p>
1212
1213<h5>Examples:</h5>
1214<table class="layout">
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]1215 <tbody>
1216 <tr>
1217 <td><tt>i1</tt></td>
1218 <td>a single-bit integer.</td>
1219 </tr><tr>
1220 <td><tt>i32</tt></td>
1221 <td>a 32-bit integer.</td>
1222 </tr><tr>
1223 <td><tt>i1942652</tt></td>
1224 <td>a really big integer of over 1 million bits.</td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1225 </tr>
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]1226 </tbody>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1227</table>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1228</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1229
1230<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1231<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1232
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1233<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1234
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1235<h5>Overview:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1236
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1237<p>The array type is a very simple derived type that arranges elements
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1238sequentially in memory. The array type requires a size (number of
1239elements) and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1240
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1241<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1242
1243<pre>
1244 [&lt;# elements&gt; x &lt;elementtype&gt;]
1245</pre>
1246
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1247<p>The number of elements is a constant integer value; elementtype may
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1248be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1249
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1250<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1251<table class="layout">
1252 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1253 <td class="left"><tt>[40 x i32]</tt></td>
1254 <td class="left">Array of 40 32-bit integer values.</td>
1255 </tr>
1256 <tr class="layout">
1257 <td class="left"><tt>[41 x i32]</tt></td>
1258 <td class="left">Array of 41 32-bit integer values.</td>
1259 </tr>
1260 <tr class="layout">
1261 <td class="left"><tt>[4 x i8]</tt></td>
1262 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1263 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1264</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1265<p>Here are some examples of multidimensional arrays:</p>
1266<table class="layout">
1267 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1268 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1269 <td class="left">3x4 array of 32-bit integer values.</td>
1270 </tr>
1271 <tr class="layout">
1272 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1273 <td class="left">12x10 array of single precision floating point values.</td>
1274 </tr>
1275 <tr class="layout">
1276 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1277 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1278 </tr>
1279</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1280
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1281<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1282length array. Normally, accesses past the end of an array are undefined in
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1283LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1284As a special case, however, zero length arrays are recognized to be variable
1285length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1286type "{ i32, [0 x float]}", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1287
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1288</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1289
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1290<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1291<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1292<div class="doc_text">
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1293
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1294<h5>Overview:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1295
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1296<p>The function type can be thought of as a function signature. It
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1297consists of a return type and a list of formal parameter types. The
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1298return 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]1299If 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]1300class types, and the struct must have at least one element.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1301
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1302<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1303
1304<pre>
1305 &lt;returntype list&gt; (&lt;parameter list&gt;)
1306</pre>
1307
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1308<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]1309specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1310which indicates that the function takes a variable number of arguments.
1311Variable argument functions can access their arguments with the <a
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1312 href="#int_varargs">variable argument handling intrinsic</a> functions.
1313'<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1314<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1315
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1316<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1317<table class="layout">
1318 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1319 <td class="left"><tt>i32 (i32)</tt></td>
1320 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1321 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1322 </tr><tr class="layout">
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]1323 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1324 </tt></td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1325 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1326 an <tt>i16</tt> that should be sign extended and a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1327 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1328 <tt>float</tt>.
1329 </td>
1330 </tr><tr class="layout">
1331 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1332 <td class="left">A vararg function that takes at least one
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1333 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1334 which returns an integer. This is the signature for <tt>printf</tt> in
1335 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1336 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1337 </tr><tr class="layout">
1338 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Devang Patel3a5bff82008-03-24 18:10:52 +0000[diff] [blame]1339 <td class="left">A function taking an <tt>i32></tt>, returning two
1340 <tt> i32 </tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1341 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1342 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1343</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1344
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1345</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1346<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1347<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1348<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1349<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1350<p>The structure type is used to represent a collection of data members
1351together in memory. The packing of the field types is defined to match
1352the ABI of the underlying processor. The elements of a structure may
1353be any type that has a size.</p>
1354<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1355and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1356field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1357instruction.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1358<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1359<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1360<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1361<table class="layout">
1362 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1363 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1364 <td class="left">A triple of three <tt>i32</tt> values</td>
1365 </tr><tr class="layout">
1366 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1367 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1368 second element is a <a href="#t_pointer">pointer</a> to a
1369 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1370 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1371 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1372</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1373</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1374
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1375<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1376<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1377</div>
1378<div class="doc_text">
1379<h5>Overview:</h5>
1380<p>The packed structure type is used to represent a collection of data members
1381together in memory. There is no padding between fields. Further, the alignment
1382of a packed structure is 1 byte. The elements of a packed structure may
1383be any type that has a size.</p>
1384<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1385and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1386field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1387instruction.</p>
1388<h5>Syntax:</h5>
1389<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1390<h5>Examples:</h5>
1391<table class="layout">
1392 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1393 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1394 <td class="left">A triple of three <tt>i32</tt> values</td>
1395 </tr><tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1396 <td class="left"><tt>&lt; { float, i32 (i32)* } &gt;</tt></td>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1397 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1398 second element is a <a href="#t_pointer">pointer</a> to a
1399 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1400 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1401 </tr>
1402</table>
1403</div>
1404
1405<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1406<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1407<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1408<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1409<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]1410reference to another object, which must live in memory. Pointer types may have
1411an optional address space attribute defining the target-specific numbered
1412address space where the pointed-to object resides. The default address space is
1413zero.</p>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1414<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1415<pre> &lt;type&gt; *<br></pre>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1416<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1417<table class="layout">
1418 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1419 <td class="left"><tt>[4x i32]*</tt></td>
1420 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1421 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1422 </tr>
1423 <tr class="layout">
1424 <td class="left"><tt>i32 (i32 *) *</tt></td>
1425 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1426 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1427 <tt>i32</tt>.</td>
1428 </tr>
1429 <tr class="layout">
1430 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1431 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1432 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1433 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1434</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1435</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1436
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1437<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1438<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1439<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1440
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1441<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1442
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1443<p>A vector type is a simple derived type that represents a vector
1444of elements. Vector types are used when multiple primitive data
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1445are operated in parallel using a single instruction (SIMD).
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1446A vector type requires a size (number of
Chris Lattnerb8d172f2005-11-10 01:44:22 +0000[diff] [blame]1447elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1448of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1449considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1450
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1451<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1452
1453<pre>
1454 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1455</pre>
1456
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1457<p>The number of elements is a constant integer value; elementtype may
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1458be any integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1459
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1460<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1461
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1462<table class="layout">
1463 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1464 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1465 <td class="left">Vector of 4 32-bit integer values.</td>
1466 </tr>
1467 <tr class="layout">
1468 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1469 <td class="left">Vector of 8 32-bit floating-point values.</td>
1470 </tr>
1471 <tr class="layout">
1472 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1473 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1474 </tr>
1475</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1476</div>
1477
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1478<!-- _______________________________________________________________________ -->
1479<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1480<div class="doc_text">
1481
1482<h5>Overview:</h5>
1483
1484<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksen8ac04ff2007-10-14 00:34:53 +0000[diff] [blame]1485corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1486In LLVM, opaque types can eventually be resolved to any type (not just a
1487structure type).</p>
1488
1489<h5>Syntax:</h5>
1490
1491<pre>
1492 opaque
1493</pre>
1494
1495<h5>Examples:</h5>
1496
1497<table class="layout">
1498 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1499 <td class="left"><tt>opaque</tt></td>
1500 <td class="left">An opaque type.</td>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1501 </tr>
1502</table>
1503</div>
1504
1505
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1506<!-- *********************************************************************** -->
1507<div class="doc_section"> <a name="constants">Constants</a> </div>
1508<!-- *********************************************************************** -->
1509
1510<div class="doc_text">
1511
1512<p>LLVM has several different basic types of constants. This section describes
1513them all and their syntax.</p>
1514
1515</div>
1516
1517<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1518<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1519
1520<div class="doc_text">
1521
1522<dl>
1523 <dt><b>Boolean constants</b></dt>
1524
1525 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1526 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1527 </dd>
1528
1529 <dt><b>Integer constants</b></dt>
1530
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1531 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1532 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1533 integer types.
1534 </dd>
1535
1536 <dt><b>Floating point constants</b></dt>
1537
1538 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1539 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]1540 notation (see below). The assembler requires the exact decimal value of
1541 a floating-point constant. For example, the assembler accepts 1.25 but
1542 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1543 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1544
1545 <dt><b>Null pointer constants</b></dt>
1546
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1547 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1548 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1549
1550</dl>
1551
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1552<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1553of floating point constants. For example, the form '<tt>double
15540x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
15554.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1556(and the only time that they are generated by the disassembler) is when a
1557floating point constant must be emitted but it cannot be represented as a
1558decimal floating point number. For example, NaN's, infinities, and other
1559special values are represented in their IEEE hexadecimal format so that
1560assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1561
1562</div>
1563
1564<!-- ======================================================================= -->
1565<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1566</div>
1567
1568<div class="doc_text">
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]1569<p>Aggregate constants arise from aggregation of simple constants
1570and smaller aggregate constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1571
1572<dl>
1573 <dt><b>Structure constants</b></dt>
1574
1575 <dd>Structure constants are represented with notation similar to structure
1576 type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner64910ee2007-12-25 20:34:52 +0000[diff] [blame]1577 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1578 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]1579 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1580 types of elements must match those specified by the type.
1581 </dd>
1582
1583 <dt><b>Array constants</b></dt>
1584
1585 <dd>Array constants are represented with notation similar to array type
1586 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1587 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1588 constants must have <a href="#t_array">array type</a>, and the number and
1589 types of elements must match those specified by the type.
1590 </dd>
1591
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1592 <dt><b>Vector constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1593
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1594 <dd>Vector constants are represented with notation similar to vector type
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1595 definitions (a comma separated list of elements, surrounded by
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1596 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]1597 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1598 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1599 match those specified by the type.
1600 </dd>
1601
1602 <dt><b>Zero initialization</b></dt>
1603
1604 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1605 value to zero of <em>any</em> type, including scalar and aggregate types.
1606 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]1607 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1608 initializers.
1609 </dd>
1610</dl>
1611
1612</div>
1613
1614<!-- ======================================================================= -->
1615<div class="doc_subsection">
1616 <a name="globalconstants">Global Variable and Function Addresses</a>
1617</div>
1618
1619<div class="doc_text">
1620
1621<p>The addresses of <a href="#globalvars">global variables</a> and <a
1622href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1623constants. These constants are explicitly referenced when the <a
1624href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1625href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1626file:</p>
1627
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1628<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1629<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]1630@X = global i32 17
1631@Y = global i32 42
1632@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1633</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1634</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1635
1636</div>
1637
1638<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1639<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1640<div class="doc_text">
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1641 <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]1642 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1643 a constant is permitted.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1644
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1645 <p>Undefined values indicate to the compiler that the program is well defined
1646 no matter what value is used, giving the compiler more freedom to optimize.
1647 </p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1648</div>
1649
1650<!-- ======================================================================= -->
1651<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1652</div>
1653
1654<div class="doc_text">
1655
1656<p>Constant expressions are used to allow expressions involving other constants
1657to be used as constants. Constant expressions may be of any <a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1658href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1659that does not have side effects (e.g. load and call are not supported). The
1660following is the syntax for constant expressions:</p>
1661
1662<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1663 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1664 <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]1665 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1666
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1667 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1668 <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]1669 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]1670
1671 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1672 <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]1673 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]1674
1675 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1676 <dd>Truncate a floating point constant to another floating point type. The
1677 size of CST must be larger than the size of TYPE. Both types must be
1678 floating point.</dd>
1679
1680 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1681 <dd>Floating point extend a constant to another type. The size of CST must be
1682 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1683
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]1684 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1685 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1686 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1687 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1688 of the same number of elements. If the value won't fit in the integer type,
1689 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1690
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1691 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1692 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1693 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1694 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1695 of the same number of elements. If the value won't fit in the integer type,
1696 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1697
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1698 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1699 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1700 constant. TYPE must be a scalar or vector floating point type. CST must be of
1701 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1702 of the same number of elements. If the value won't fit in the floating point
1703 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1704
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1705 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1706 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1707 constant. TYPE must be a scalar or vector floating point type. CST must be of
1708 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1709 of the same number of elements. If the value won't fit in the floating point
1710 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1711
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1712 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1713 <dd>Convert a pointer typed constant to the corresponding integer constant
1714 TYPE must be an integer type. CST must be of pointer type. The CST value is
1715 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1716
1717 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1718 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1719 pointer type. CST must be of integer type. The CST value is zero extended,
1720 truncated, or unchanged to make it fit in a pointer size. This one is
1721 <i>really</i> dangerous!</dd>
1722
1723 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1724 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1725 identical (same number of bits). The conversion is done as if the CST value
1726 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]1727 with this operator, just the type. This can be used for conversion of
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1728 vector types to any other type, as long as they have the same bit width. For
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1729 pointers it is only valid to cast to another pointer type.
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1730 </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1731
1732 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1733
1734 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1735 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1736 instruction, the index list may have zero or more indexes, which are required
1737 to make sense for the type of "CSTPTR".</dd>
1738
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1739 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1740
1741 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1742 constants.</dd>
1743
1744 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1745 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1746
1747 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1748 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1749
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]1750 <dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
1751 <dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
1752
1753 <dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
1754 <dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
1755
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1756 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1757
1758 <dd>Perform the <a href="#i_extractelement">extractelement
1759 operation</a> on constants.
1760
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1761 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1762
1763 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1764 operation</a> on constants.</dd>
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1765
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1766
1767 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1768
1769 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1770 operation</a> on constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1771
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1772 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1773
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1774 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1775 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1776 binary</a> operations. The constraints on operands are the same as those for
1777 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1778 values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1779</dl>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1780</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]1781
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1782<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1783<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1784<!-- *********************************************************************** -->
1785
1786<!-- ======================================================================= -->
1787<div class="doc_subsection">
1788<a name="inlineasm">Inline Assembler Expressions</a>
1789</div>
1790
1791<div class="doc_text">
1792
1793<p>
1794LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1795Module-Level Inline Assembly</a>) through the use of a special value. This
1796value represents the inline assembler as a string (containing the instructions
1797to emit), a list of operand constraints (stored as a string), and a flag that
1798indicates whether or not the inline asm expression has side effects. An example
1799inline assembler expression is:
1800</p>
1801
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1802<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1803<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1804i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1805</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1806</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1807
1808<p>
1809Inline assembler expressions may <b>only</b> be used as the callee operand of
1810a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
1811</p>
1812
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1813<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1814<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1815%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]1816</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1817</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1818
1819<p>
1820Inline asms with side effects not visible in the constraint list must be marked
1821as having side effects. This is done through the use of the
1822'<tt>sideeffect</tt>' keyword, like so:
1823</p>
1824
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1825<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1826<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1827call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1828</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1829</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1830
1831<p>TODO: The format of the asm and constraints string still need to be
1832documented here. Constraints on what can be done (e.g. duplication, moving, etc
1833need to be documented).
1834</p>
1835
1836</div>
1837
1838<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1839<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
1840<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1841
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1842<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1843
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1844<p>The LLVM instruction set consists of several different
1845classifications of instructions: <a href="#terminators">terminator
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1846instructions</a>, <a href="#binaryops">binary instructions</a>,
1847<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1848 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
1849instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1850
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1851</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1852
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1853<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1854<div class="doc_subsection"> <a name="terminators">Terminator
1855Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1856
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1857<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1858
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1859<p>As mentioned <a href="#functionstructure">previously</a>, every
1860basic block in a program ends with a "Terminator" instruction, which
1861indicates which block should be executed after the current block is
1862finished. These terminator instructions typically yield a '<tt>void</tt>'
1863value: they produce control flow, not values (the one exception being
1864the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1865<p>There are six different terminator instructions: the '<a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1866 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
1867instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1868the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
1869 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
1870 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1871
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1872</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1873
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1874<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1875<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
1876Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1877<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1878<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1879<pre> 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]1880 ret void <i>; Return from void function</i>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1881 ret &lt;type&gt; &lt;value&gt;, &lt;type&gt; &lt;value&gt; <i>; Return two values from a non-void function </i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1882</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1883
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1884<h5>Overview:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1885
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1886<p>The '<tt>ret</tt>' instruction is used to return control flow (and a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1887value) from a function back to the caller.</p>
John Criswell4457dc92004-04-09 16:48:45 +0000[diff] [blame]1888<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1889returns value(s) and then causes control flow, and one that just causes
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1890control flow to occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1891
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1892<h5>Arguments:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1893
1894<p>The '<tt>ret</tt>' instruction may return zero, one or multiple values.
1895The type of each return value must be a '<a href="#t_firstclass">first
1896class</a>' type. Note that a function is not <a href="#wellformed">well
1897formed</a> if there exists a '<tt>ret</tt>' instruction inside of the
1898function that returns values that do not match the return type of the
1899function.</p>
1900
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1901<h5>Semantics:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1902
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1903<p>When the '<tt>ret</tt>' instruction is executed, control flow
1904returns back to the calling function's context. If the caller is a "<a
John Criswellfa081872004-06-25 15:16:57 +0000[diff] [blame]1905 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1906the instruction after the call. If the caller was an "<a
1907 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1908at the beginning of the "normal" destination block. If the instruction
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1909returns a value, that value shall set the call or invoke instruction's
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1910return value. If the instruction returns multiple values then these
Devang Patel0dbb4a12008-03-11 05:51:59 +0000[diff] [blame]1911values can only be accessed through a '<a href="#i_getresult"><tt>getresult</tt>
1912</a>' instruction.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1913
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1914<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1915
1916<pre>
1917 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1918 ret void <i>; Return from a void function</i>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1919 ret i32 4, i8 2 <i>; Return two values 4 and 2 </i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1920</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1921</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1922<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1923<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1924<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1925<h5>Syntax:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1926<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]1927</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1928<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1929<p>The '<tt>br</tt>' instruction is used to cause control flow to
1930transfer to a different basic block in the current function. There are
1931two forms of this instruction, corresponding to a conditional branch
1932and an unconditional branch.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1933<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1934<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1935single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1936unconditional form of the '<tt>br</tt>' instruction takes a single
1937'<tt>label</tt>' value as a target.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1938<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1939<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1940argument is evaluated. If the value is <tt>true</tt>, control flows
1941to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
1942control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1943<h5>Example:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1944<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]1945 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]1946</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1947<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1948<div class="doc_subsubsection">
1949 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
1950</div>
1951
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1952<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1953<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1954
1955<pre>
1956 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
1957</pre>
1958
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1959<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1960
1961<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
1962several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1963instruction, allowing a branch to occur to one of many possible
1964destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1965
1966
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1967<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1968
1969<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
1970comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
1971an array of pairs of comparison value constants and '<tt>label</tt>'s. The
1972table is not allowed to contain duplicate constant entries.</p>
1973
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1974<h5>Semantics:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1975
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1976<p>The <tt>switch</tt> instruction specifies a table of values and
1977destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]1978table is searched for the given value. If the value is found, control flow is
1979transfered to the corresponding destination; otherwise, control flow is
1980transfered to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1981
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1982<h5>Implementation:</h5>
1983
1984<p>Depending on properties of the target machine and the particular
1985<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]1986ways. For example, it could be generated as a series of chained conditional
1987branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1988
1989<h5>Example:</h5>
1990
1991<pre>
1992 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1993 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1994 switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1995
1996 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1997 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1998
1999 <i>; Implement a jump table:</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2000 switch i32 %val, label %otherwise [ i32 0, label %onzero
2001 i32 1, label %onone
2002 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2003</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2004</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2005
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2006<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2007<div class="doc_subsubsection">
2008 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2009</div>
2010
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2011<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2012
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2013<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2014
2015<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2016 &lt;result&gt; = invoke [<a href="#callingconv">cconv</a>] &lt;ptr to function ty&gt; &lt;function ptr val&gt;(&lt;function args&gt;)
Chris Lattner76b8a332006-05-14 18:23:06 +0000[diff] [blame]2017 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2018</pre>
2019
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2020<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2021
2022<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
2023function, with the possibility of control flow transfer to either the
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2024'<tt>normal</tt>' label or the
2025'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2026"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
2027"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2028href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]2029continued at the dynamically nearest "exception" label. If the callee function
Devang Patel0dbb4a12008-03-11 05:51:59 +0000[diff] [blame]2030returns multiple values then individual return values are only accessible through
2031a '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2032
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2033<h5>Arguments:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2034
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2035<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2036
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2037<ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2038 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]2039 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2040 convention</a> the call should use. If none is specified, the call defaults
2041 to using C calling conventions.
2042 </li>
2043 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
2044 function value being invoked. In most cases, this is a direct function
2045 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
2046 an arbitrary pointer to function value.
2047 </li>
2048
2049 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
2050 function to be invoked. </li>
2051
2052 <li>'<tt>function args</tt>': argument list whose types match the function
2053 signature argument types. If the function signature indicates the function
2054 accepts a variable number of arguments, the extra arguments can be
2055 specified. </li>
2056
2057 <li>'<tt>normal label</tt>': the label reached when the called function
2058 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
2059
2060 <li>'<tt>exception label</tt>': the label reached when a callee returns with
2061 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
2062
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2063</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2064
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2065<h5>Semantics:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2066
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2067<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2068href="#i_call">call</a></tt>' instruction in most regards. The primary
2069difference is that it establishes an association with a label, which is used by
2070the runtime library to unwind the stack.</p>
2071
2072<p>This instruction is used in languages with destructors to ensure that proper
2073cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2074exception. Additionally, this is important for implementation of
2075'<tt>catch</tt>' clauses in high-level languages that support them.</p>
2076
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2077<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2078<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2079 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2080 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2081 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2082 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2083</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2084</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2085
2086
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2087<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2088
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2089<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2090Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2091
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2092<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2093
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2094<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2095<pre>
2096 unwind
2097</pre>
2098
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2099<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2100
2101<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
2102at the first callee in the dynamic call stack which used an <a
2103href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
2104primarily used to implement exception handling.</p>
2105
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2106<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2107
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]2108<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2109immediately halt. The dynamic call stack is then searched for the first <a
2110href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
2111execution continues at the "exceptional" destination block specified by the
2112<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
2113dynamic call chain, undefined behavior results.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2114</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2115
2116<!-- _______________________________________________________________________ -->
2117
2118<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2119Instruction</a> </div>
2120
2121<div class="doc_text">
2122
2123<h5>Syntax:</h5>
2124<pre>
2125 unreachable
2126</pre>
2127
2128<h5>Overview:</h5>
2129
2130<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
2131instruction is used to inform the optimizer that a particular portion of the
2132code is not reachable. This can be used to indicate that the code after a
2133no-return function cannot be reached, and other facts.</p>
2134
2135<h5>Semantics:</h5>
2136
2137<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
2138</div>
2139
2140
2141
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2142<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2143<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2144<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2145<p>Binary operators are used to do most of the computation in a
Chris Lattner5a158142008-04-01 18:47:32 +0000[diff] [blame]2146program. They require two operands of the same type, execute an operation on them, and
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2147produce a single value. The operands might represent
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2148multiple 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]2149The result value has the same type as its operands.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2150<p>There are several different binary operators:</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2151</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2152<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2153<div class="doc_subsubsection">
2154 <a name="i_add">'<tt>add</tt>' Instruction</a>
2155</div>
2156
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2157<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2158
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2159<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2160
2161<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2162 &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]2163</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2164
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2165<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2166
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2167<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2168
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2169<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2170
2171<p>The two arguments to the '<tt>add</tt>' instruction must be <a
2172 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
2173 <a href="#t_vector">vector</a> values. Both arguments must have identical
2174 types.</p>
2175
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2176<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2177
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2178<p>The value produced is the integer or floating point sum of the two
2179operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2180
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2181<p>If an integer sum has unsigned overflow, the result returned is the
2182mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2183the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2184
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2185<p>Because LLVM integers use a two's complement representation, this
2186instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2187
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2188<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2189
2190<pre>
2191 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2192</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2193</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2194<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2195<div class="doc_subsubsection">
2196 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2197</div>
2198
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2199<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2200
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2201<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2202
2203<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2204 &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]2205</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2206
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2207<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2208
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2209<p>The '<tt>sub</tt>' instruction returns the difference of its two
2210operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2211
2212<p>Note that the '<tt>sub</tt>' instruction is used to represent the
2213'<tt>neg</tt>' instruction present in most other intermediate
2214representations.</p>
2215
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2216<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2217
2218<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
2219 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2220 or <a href="#t_vector">vector</a> values. Both arguments must have identical
2221 types.</p>
2222
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2223<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2224
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2225<p>The value produced is the integer or floating point difference of
2226the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2227
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2228<p>If an integer difference has unsigned overflow, the result returned is the
2229mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2230the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2231
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2232<p>Because LLVM integers use a two's complement representation, this
2233instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2234
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2235<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2236<pre>
2237 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2238 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2239</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2240</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2241
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2242<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2243<div class="doc_subsubsection">
2244 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2245</div>
2246
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2247<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2248
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2249<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2250<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]2251</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2252<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2253<p>The '<tt>mul</tt>' instruction returns the product of its two
2254operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2255
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2256<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2257
2258<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
2259href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2260or <a href="#t_vector">vector</a> values. Both arguments must have identical
2261types.</p>
2262
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2263<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2264
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2265<p>The value produced is the integer or floating point product of the
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2266two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2267
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2268<p>If the result of an integer multiplication has unsigned overflow,
2269the result returned is the mathematical result modulo
22702<sup>n</sup>, where n is the bit width of the result.</p>
2271<p>Because LLVM integers use a two's complement representation, and the
2272result is the same width as the operands, this instruction returns the
2273correct result for both signed and unsigned integers. If a full product
2274(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
2275should be sign-extended or zero-extended as appropriate to the
2276width of the full product.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2277<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2278<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]2279</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2280</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2281
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2282<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2283<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2284</a></div>
2285<div class="doc_text">
2286<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2287<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]2288</pre>
2289<h5>Overview:</h5>
2290<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2291operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2292
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2293<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2294
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2295<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2296<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2297values. Both arguments must have identical types.</p>
2298
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2299<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2300
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2301<p>The value produced is the unsigned integer quotient of the two operands.</p>
2302<p>Note that unsigned integer division and signed integer division are distinct
2303operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2304<p>Division by zero leads to undefined behavior.</p>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2305<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2306<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]2307</pre>
2308</div>
2309<!-- _______________________________________________________________________ -->
2310<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2311</a> </div>
2312<div class="doc_text">
2313<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2314<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2315 &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]2316</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2317
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2318<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2319
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2320<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2321operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2322
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2323<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2324
2325<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2326<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2327values. Both arguments must have identical types.</p>
2328
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2329<h5>Semantics:</h5>
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2330<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]2331<p>Note that signed integer division and unsigned integer division are distinct
2332operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2333<p>Division by zero leads to undefined behavior. Overflow also leads to
2334undefined behavior; this is a rare case, but can occur, for example,
2335by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2336<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2337<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]2338</pre>
2339</div>
2340<!-- _______________________________________________________________________ -->
2341<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2342Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2343<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2344<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2345<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2346 &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]2347</pre>
2348<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2349
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2350<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2351operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2352
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2353<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2354
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2355<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2356<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2357of floating point values. Both arguments must have identical types.</p>
2358
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2359<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2360
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2361<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2362
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2363<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2364
2365<pre>
2366 &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]2367</pre>
2368</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2369
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2370<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2371<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2372</div>
2373<div class="doc_text">
2374<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2375<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]2376</pre>
2377<h5>Overview:</h5>
2378<p>The '<tt>urem</tt>' instruction returns the remainder from the
2379unsigned division of its two arguments.</p>
2380<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2381<p>The two arguments to the '<tt>urem</tt>' instruction must be
2382<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2383values. Both arguments must have identical types.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2384<h5>Semantics:</h5>
2385<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2386This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2387<p>Note that unsigned integer remainder and signed integer remainder are
2388distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
2389<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2390<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2391<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]2392</pre>
2393
2394</div>
2395<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2396<div class="doc_subsubsection">
2397 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
2398</div>
2399
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2400<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2401
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2402<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2403
2404<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2405 &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]2406</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2407
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2408<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2409
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2410<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2411signed division of its two operands. This instruction can also take
2412<a href="#t_vector">vector</a> versions of the values in which case
2413the elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]2414
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2415<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2416
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2417<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2418<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2419values. Both arguments must have identical types.</p>
2420
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2421<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2422
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2423<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2424has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
2425operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2426a value. For more information about the difference, see <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2427 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2428Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencer64f5c6c2007-03-24 22:40:44 +0000[diff] [blame]2429please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2430Wikipedia: modulo operation</a>.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2431<p>Note that signed integer remainder and unsigned integer remainder are
2432distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
2433<p>Taking the remainder of a division by zero leads to undefined behavior.
2434Overflow also leads to undefined behavior; this is a rare case, but can occur,
2435for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
2436(The remainder doesn't actually overflow, but this rule lets srem be
2437implemented using instructions that return both the result of the division
2438and the remainder.)</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2439<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2440<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]2441</pre>
2442
2443</div>
2444<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2445<div class="doc_subsubsection">
2446 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
2447
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2448<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2449
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2450<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2451<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]2452</pre>
2453<h5>Overview:</h5>
2454<p>The '<tt>frem</tt>' instruction returns the remainder from the
2455division of its two operands.</p>
2456<h5>Arguments:</h5>
2457<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2458<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2459of floating point values. Both arguments must have identical types.</p>
2460
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2461<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2462
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2463<p>This instruction returns the <i>remainder</i> of a division.
2464The remainder has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2465
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2466<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2467
2468<pre>
2469 &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]2470</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2471</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]2472
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2473<!-- ======================================================================= -->
2474<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2475Operations</a> </div>
2476<div class="doc_text">
2477<p>Bitwise binary operators are used to do various forms of
2478bit-twiddling in a program. They are generally very efficient
2479instructions and can commonly be strength reduced from other
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2480instructions. They require two operands of the same type, execute an operation on them,
2481and 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]2482</div>
2483
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2484<!-- _______________________________________________________________________ -->
2485<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2486Instruction</a> </div>
2487<div class="doc_text">
2488<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2489<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]2490</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2491
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2492<h5>Overview:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2493
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2494<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2495the left a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2496
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2497<h5>Arguments:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2498
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2499<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2500 href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2501type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2502
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2503<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2504
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2505<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
2506where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
2507equal 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]2508
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2509<h5>Example:</h5><pre>
2510 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2511 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2512 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2513 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2514</pre>
2515</div>
2516<!-- _______________________________________________________________________ -->
2517<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2518Instruction</a> </div>
2519<div class="doc_text">
2520<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2521<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]2522</pre>
2523
2524<h5>Overview:</h5>
2525<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2526operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2527
2528<h5>Arguments:</h5>
2529<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2530<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]2531type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2532
2533<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2534
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2535<p>This instruction always performs a logical shift right operation. The most
2536significant bits of the result will be filled with zero bits after the
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2537shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
2538the number of bits in <tt>op1</tt>, the result is undefined.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2539
2540<h5>Example:</h5>
2541<pre>
2542 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2543 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2544 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2545 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2546 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2547</pre>
2548</div>
2549
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2550<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2551<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2552Instruction</a> </div>
2553<div class="doc_text">
2554
2555<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2556<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]2557</pre>
2558
2559<h5>Overview:</h5>
2560<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2561operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2562
2563<h5>Arguments:</h5>
2564<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2565<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]2566type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2567
2568<h5>Semantics:</h5>
2569<p>This instruction always performs an arithmetic shift right operation,
2570The most significant bits of the result will be filled with the sign bit
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2571of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
2572larger than the number of bits in <tt>op1</tt>, the result is undefined.
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2573</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2574
2575<h5>Example:</h5>
2576<pre>
2577 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2578 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2579 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2580 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2581 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2582</pre>
2583</div>
2584
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2585<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2586<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2587Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2588
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2589<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2590
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2591<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2592
2593<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2594 &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]2595</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2596
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2597<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2598
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2599<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2600its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2601
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2602<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2603
2604<p>The two arguments to the '<tt>and</tt>' instruction must be
2605<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2606values. Both arguments must have identical types.</p>
2607
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2608<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2609<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2610<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2611<div style="align: center">
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2612<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2613 <tbody>
2614 <tr>
2615 <td>In0</td>
2616 <td>In1</td>
2617 <td>Out</td>
2618 </tr>
2619 <tr>
2620 <td>0</td>
2621 <td>0</td>
2622 <td>0</td>
2623 </tr>
2624 <tr>
2625 <td>0</td>
2626 <td>1</td>
2627 <td>0</td>
2628 </tr>
2629 <tr>
2630 <td>1</td>
2631 <td>0</td>
2632 <td>0</td>
2633 </tr>
2634 <tr>
2635 <td>1</td>
2636 <td>1</td>
2637 <td>1</td>
2638 </tr>
2639 </tbody>
2640</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2641</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2642<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2643<pre>
2644 &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]2645 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2646 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2647</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2648</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2649<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2650<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2651<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2652<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2653<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]2654</pre>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2655<h5>Overview:</h5>
2656<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2657or of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2658<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2659
2660<p>The two arguments to the '<tt>or</tt>' instruction must be
2661<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2662values. Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2663<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2664<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2665<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2666<div style="align: center">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2667<table border="1" cellspacing="0" cellpadding="4">
2668 <tbody>
2669 <tr>
2670 <td>In0</td>
2671 <td>In1</td>
2672 <td>Out</td>
2673 </tr>
2674 <tr>
2675 <td>0</td>
2676 <td>0</td>
2677 <td>0</td>
2678 </tr>
2679 <tr>
2680 <td>0</td>
2681 <td>1</td>
2682 <td>1</td>
2683 </tr>
2684 <tr>
2685 <td>1</td>
2686 <td>0</td>
2687 <td>1</td>
2688 </tr>
2689 <tr>
2690 <td>1</td>
2691 <td>1</td>
2692 <td>1</td>
2693 </tr>
2694 </tbody>
2695</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2696</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2697<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2698<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2699 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2700 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2701</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2702</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2703<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2704<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2705Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2706<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2707<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2708<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]2709</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2710<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2711<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2712or of its two operands. The <tt>xor</tt> is used to implement the
2713"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2714<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2715<p>The two arguments to the '<tt>xor</tt>' instruction must be
2716<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2717values. Both arguments must have identical types.</p>
2718
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2719<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2720
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2721<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2722<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2723<div style="align: center">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2724<table border="1" cellspacing="0" cellpadding="4">
2725 <tbody>
2726 <tr>
2727 <td>In0</td>
2728 <td>In1</td>
2729 <td>Out</td>
2730 </tr>
2731 <tr>
2732 <td>0</td>
2733 <td>0</td>
2734 <td>0</td>
2735 </tr>
2736 <tr>
2737 <td>0</td>
2738 <td>1</td>
2739 <td>1</td>
2740 </tr>
2741 <tr>
2742 <td>1</td>
2743 <td>0</td>
2744 <td>1</td>
2745 </tr>
2746 <tr>
2747 <td>1</td>
2748 <td>1</td>
2749 <td>0</td>
2750 </tr>
2751 </tbody>
2752</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2753</div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2754<p> </p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2755<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2756<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2757 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2758 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2759 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2760</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2761</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2762
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2763<!-- ======================================================================= -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2764<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2765 <a name="vectorops">Vector Operations</a>
2766</div>
2767
2768<div class="doc_text">
2769
2770<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2771target-independent manner. These instructions cover the element-access and
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2772vector-specific operations needed to process vectors effectively. While LLVM
2773does directly support these vector operations, many sophisticated algorithms
2774will want to use target-specific intrinsics to take full advantage of a specific
2775target.</p>
2776
2777</div>
2778
2779<!-- _______________________________________________________________________ -->
2780<div class="doc_subsubsection">
2781 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
2782</div>
2783
2784<div class="doc_text">
2785
2786<h5>Syntax:</h5>
2787
2788<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2789 &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]2790</pre>
2791
2792<h5>Overview:</h5>
2793
2794<p>
2795The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2796element from a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2797</p>
2798
2799
2800<h5>Arguments:</h5>
2801
2802<p>
2803The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2804value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2805an index indicating the position from which to extract the element.
2806The index may be a variable.</p>
2807
2808<h5>Semantics:</h5>
2809
2810<p>
2811The result is a scalar of the same type as the element type of
2812<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
2813<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
2814results are undefined.
2815</p>
2816
2817<h5>Example:</h5>
2818
2819<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2820 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2821</pre>
2822</div>
2823
2824
2825<!-- _______________________________________________________________________ -->
2826<div class="doc_subsubsection">
2827 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
2828</div>
2829
2830<div class="doc_text">
2831
2832<h5>Syntax:</h5>
2833
2834<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]2835 &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]2836</pre>
2837
2838<h5>Overview:</h5>
2839
2840<p>
2841The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2842element into a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2843</p>
2844
2845
2846<h5>Arguments:</h5>
2847
2848<p>
2849The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2850value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2851scalar value whose type must equal the element type of the first
2852operand. The third operand is an index indicating the position at
2853which to insert the value. The index may be a variable.</p>
2854
2855<h5>Semantics:</h5>
2856
2857<p>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2858The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2859element values are those of <tt>val</tt> except at position
2860<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
2861exceeds the length of <tt>val</tt>, the results are undefined.
2862</p>
2863
2864<h5>Example:</h5>
2865
2866<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2867 %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]2868</pre>
2869</div>
2870
2871<!-- _______________________________________________________________________ -->
2872<div class="doc_subsubsection">
2873 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
2874</div>
2875
2876<div class="doc_text">
2877
2878<h5>Syntax:</h5>
2879
2880<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2881 &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;n x i32&gt; &lt;mask&gt; <i>; yields &lt;n x &lt;ty&gt;&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2882</pre>
2883
2884<h5>Overview:</h5>
2885
2886<p>
2887The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
2888from two input vectors, returning a vector of the same type.
2889</p>
2890
2891<h5>Arguments:</h5>
2892
2893<p>
2894The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
2895with types that match each other and types that match the result of the
2896instruction. The third argument is a shuffle mask, which has the same number
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2897of elements as the other vector type, but whose element type is always 'i32'.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2898</p>
2899
2900<p>
2901The shuffle mask operand is required to be a constant vector with either
2902constant integer or undef values.
2903</p>
2904
2905<h5>Semantics:</h5>
2906
2907<p>
2908The elements of the two input vectors are numbered from left to right across
2909both of the vectors. The shuffle mask operand specifies, for each element of
2910the result vector, which element of the two input registers the result element
2911gets. The element selector may be undef (meaning "don't care") and the second
2912operand may be undef if performing a shuffle from only one vector.
2913</p>
2914
2915<h5>Example:</h5>
2916
2917<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2918 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2919 &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]2920 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
2921 &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.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2922</pre>
2923</div>
2924
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]2925
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2926<!-- ======================================================================= -->
2927<div class="doc_subsection">
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]2928 <a name="aggregateops">Aggregate Operations</a>
2929</div>
2930
2931<div class="doc_text">
2932
2933<p>LLVM supports several instructions for working with aggregate values.
2934</p>
2935
2936</div>
2937
2938<!-- _______________________________________________________________________ -->
2939<div class="doc_subsubsection">
2940 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
2941</div>
2942
2943<div class="doc_text">
2944
2945<h5>Syntax:</h5>
2946
2947<pre>
2948 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
2949</pre>
2950
2951<h5>Overview:</h5>
2952
2953<p>
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]2954The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
2955or array element from an aggregate value.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]2956</p>
2957
2958
2959<h5>Arguments:</h5>
2960
2961<p>
2962The first operand of an '<tt>extractvalue</tt>' instruction is a
2963value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]2964type. The operands are constant indices to specify which value to extract
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]2965in a similar manner as indices in a
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]2966'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
2967</p>
2968
2969<h5>Semantics:</h5>
2970
2971<p>
2972The result is the value at the position in the aggregate specified by
2973the index operands.
2974</p>
2975
2976<h5>Example:</h5>
2977
2978<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]2979 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]2980</pre>
2981</div>
2982
2983
2984<!-- _______________________________________________________________________ -->
2985<div class="doc_subsubsection">
2986 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
2987</div>
2988
2989<div class="doc_text">
2990
2991<h5>Syntax:</h5>
2992
2993<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]2994 &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]2995</pre>
2996
2997<h5>Overview:</h5>
2998
2999<p>
3000The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3001into a struct field or array element in an aggregate.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3002</p>
3003
3004
3005<h5>Arguments:</h5>
3006
3007<p>
3008The first operand of an '<tt>insertvalue</tt>' instruction is a
3009value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
3010The second operand is a first-class value to insert.
Dan Gohmanc4b49eb2008-05-23 21:53:15 +0000[diff] [blame]3011The following operands are constant indices
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3012indicating the position at which to insert the value in a similar manner as
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3013indices in a
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3014'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3015The value to insert must have the same type as the value identified
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3016by the indices.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3017
3018<h5>Semantics:</h5>
3019
3020<p>
3021The result is an aggregate of the same type as <tt>val</tt>. Its
3022value is that of <tt>val</tt> except that the value at the position
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3023specified by the indices is that of <tt>elt</tt>.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3024</p>
3025
3026<h5>Example:</h5>
3027
3028<pre>
Dan Gohman52bb2db2008-06-23 15:26:37 +0000[diff] [blame]3029 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3030</pre>
3031</div>
3032
3033
3034<!-- ======================================================================= -->
3035<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3036 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3037</div>
3038
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3039<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3040
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3041<p>A key design point of an SSA-based representation is how it
3042represents memory. In LLVM, no memory locations are in SSA form, which
3043makes things very simple. This section describes how to read, write,
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3044allocate, and free memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3045
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3046</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3047
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3048<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3049<div class="doc_subsubsection">
3050 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3051</div>
3052
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3053<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3054
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3055<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3056
3057<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3058 &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]3059</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3060
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3061<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3062
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3063<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]3064heap and returns a pointer to it. The object is always allocated in the generic
3065address space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3066
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3067<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3068
3069<p>The '<tt>malloc</tt>' instruction allocates
3070<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswell6e4ca612004-02-24 16:13:56 +0000[diff] [blame]3071bytes of memory from the operating system and returns a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3072appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3073number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3074If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3075be aligned to at least that boundary. If not specified, or if zero, the target can
3076choose to align the allocation on any convenient boundary.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3077
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3078<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3079
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3080<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3081
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3082<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3083a pointer is returned. The result of a zero byte allocattion is undefined. The
3084result is null if there is insufficient memory available.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3085
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3086<h5>Example:</h5>
3087
3088<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3089 %array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3090
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3091 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3092 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3093 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3094 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3095 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3096</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3097</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3098
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3099<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3100<div class="doc_subsubsection">
3101 <a name="i_free">'<tt>free</tt>' Instruction</a>
3102</div>
3103
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3104<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3105
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3106<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3107
3108<pre>
3109 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3110</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3111
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3112<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3113
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3114<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]3115memory heap to be reallocated in the future.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3116
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3117<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3118
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3119<p>'<tt>value</tt>' shall be a pointer value that points to a value
3120that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
3121instruction.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3122
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3123<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3124
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3125<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattnere0db56d2008-04-19 22:41:32 +0000[diff] [blame]3126after this instruction executes. If the pointer is null, the operation
3127is a noop.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3128
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3129<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3130
3131<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3132 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
3133 free [4 x i8]* %array
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3134</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3135</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3136
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3137<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3138<div class="doc_subsubsection">
3139 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3140</div>
3141
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3142<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3143
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3144<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3145
3146<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3147 &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]3148</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3149
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3150<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3151
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3152<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
3153currently executing function, to be automatically released when this function
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]3154returns to its caller. The object is always allocated in the generic address
3155space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3156
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3157<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3158
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3159<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3160bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3161appropriate type to the program. If "NumElements" is specified, it is the
3162number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3163If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3164to be aligned to at least that boundary. If not specified, or if zero, the target
3165can choose to align the allocation on any convenient boundary.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3166
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3167<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3168
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3169<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3170
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3171<p>Memory is allocated; a pointer is returned. The operation is undefiend if
3172there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3173memory is automatically released when the function returns. The '<tt>alloca</tt>'
3174instruction is commonly used to represent automatic variables that must
3175have an address available. When the function returns (either with the <tt><a
John Criswelldae2e932005-05-12 16:55:34 +0000[diff] [blame]3176 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]3177instructions), the memory is reclaimed. Allocating zero bytes
3178is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3179
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3180<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3181
3182<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3183 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3184 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3185 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3186 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3187</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3188</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3189
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3190<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3191<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3192Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3193<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3194<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]3195<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]3196<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3197<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3198<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3199<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]3200address from which to load. The pointer must point to a <a
Chris Lattnere53e5082004-06-03 22:57:15 +0000[diff] [blame]3201 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]3202marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3203the number or order of execution of this <tt>load</tt> with other
3204volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3205instructions. </p>
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3206<p>
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3207The optional constant "align" argument specifies the alignment of the operation
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3208(that is, the alignment of the memory address). A value of 0 or an
3209omitted "align" argument means that the operation has the preferential
3210alignment for the target. It is the responsibility of the code emitter
3211to ensure that the alignment information is correct. Overestimating
3212the alignment results in an undefined behavior. Underestimating the
3213alignment may produce less efficient code. An alignment of 1 is always
3214safe.
3215</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3216<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3217<p>The location of memory pointed to is loaded.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3218<h5>Examples:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3219<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3220 <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3221 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
3222 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3223</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3224</div>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3225<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3226<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3227Instruction</a> </div>
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]3228<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3229<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]3230<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
3231 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]3232</pre>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3233<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3234<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3235<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3236<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3237to 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]3238operand must be a pointer to the <a href="#t_firstclass">first class</a> type
3239of the '<tt>&lt;value&gt;</tt>'
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]3240operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3241optimizer is not allowed to modify the number or order of execution of
3242this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
3243 href="#i_store">store</a></tt> instructions.</p>
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3244<p>
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3245The optional constant "align" argument specifies the alignment of the operation
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3246(that is, the alignment of the memory address). A value of 0 or an
3247omitted "align" argument means that the operation has the preferential
3248alignment for the target. It is the responsibility of the code emitter
3249to ensure that the alignment information is correct. Overestimating
3250the alignment results in an undefined behavior. Underestimating the
3251alignment may produce less efficient code. An alignment of 1 is always
3252safe.
3253</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3254<h5>Semantics:</h5>
3255<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
3256at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3257<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3258<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]3259 store i32 3, i32* %ptr <i>; yields {void}</i>
3260 %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]3261</pre>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3262</div>
3263
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3264<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3265<div class="doc_subsubsection">
3266 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3267</div>
3268
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3269<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3270<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3271<pre>
3272 &lt;result&gt; = getelementptr &lt;ty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
3273</pre>
3274
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3275<h5>Overview:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3276
3277<p>
3278The '<tt>getelementptr</tt>' instruction is used to get the address of a
3279subelement of an aggregate data structure.</p>
3280
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3281<h5>Arguments:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3282
Reid Spencer85f5b5b2006-12-04 21:29:24 +0000[diff] [blame]3283<p>This instruction takes a list of integer operands that indicate what
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3284elements of the aggregate object to index to. The actual types of the arguments
3285provided depend on the type of the first pointer argument. The
3286'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3287levels of a structure or to a specific index in an array. When indexing into a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3288structure, only <tt>i32</tt> integer constants are allowed. When indexing
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]3289into an array or pointer, only integers of 32 or 64 bits are allowed; 32-bit
3290values will be sign extended to 64-bits if required.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3291
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3292<p>For example, let's consider a C code fragment and how it gets
3293compiled to LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3294
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3295<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3296<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3297struct RT {
3298 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3299 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3300 char C;
3301};
3302struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3303 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3304 double Y;
3305 struct RT Z;
3306};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3307
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3308int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3309 return &amp;s[1].Z.B[5][13];
3310}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3311</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3312</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3313
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3314<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3315
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3316<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3317<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3318%RT = type { i8 , [10 x [20 x i32]], i8 }
3319%ST = type { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3320
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3321define i32* %foo(%ST* %s) {
3322entry:
3323 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3324 ret i32* %reg
3325}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3326</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3327</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3328
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3329<h5>Semantics:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3330
3331<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]3332on the pointer type that is being indexed into. <a href="#t_pointer">Pointer</a>
Reid Spencer85f5b5b2006-12-04 21:29:24 +0000[diff] [blame]3333and <a href="#t_array">array</a> types can use a 32-bit or 64-bit
Reid Spencer42ddd842006-12-03 16:53:48 +0000[diff] [blame]3334<a href="#t_integer">integer</a> type but the value will always be sign extended
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3335to 64-bits. <a href="#t_struct">Structure</a> and <a href="#t_pstruct">packed
3336structure</a> types require <tt>i32</tt> <b>constants</b>.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3337
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3338<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]3339type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3340}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3341the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3342i8 }</tt>' type, another structure. The third index indexes into the second
3343element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3344array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3345'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
3346to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3347
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3348<p>Note that it is perfectly legal to index partially through a
3349structure, returning a pointer to an inner element. Because of this,
3350the LLVM code for the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3351
3352<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3353 define i32* %foo(%ST* %s) {
3354 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3355 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3356 %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]3357 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3358 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
3359 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3360 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3361</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3362
3363<p>Note that it is undefined to access an array out of bounds: array and
3364pointer indexes must always be within the defined bounds of the array type.
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]3365The one exception for this rule is zero length arrays. These arrays are
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3366defined to be accessible as variable length arrays, which requires access
3367beyond the zero'th element.</p>
3368
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3369<p>The getelementptr instruction is often confusing. For some more insight
3370into how it works, see <a href="GetElementPtr.html">the getelementptr
3371FAQ</a>.</p>
3372
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3373<h5>Example:</h5>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3374
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3375<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3376 <i>; yields [12 x i8]*:aptr</i>
3377 %aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3378</pre>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3379</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3380
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3381<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3382<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3383</div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3384<div class="doc_text">
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3385<p>The instructions in this category are the conversion instructions (casting)
3386which all take a single operand and a type. They perform various bit conversions
3387on the operand.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3388</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3389
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3390<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3391<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3392 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
3393</div>
3394<div class="doc_text">
3395
3396<h5>Syntax:</h5>
3397<pre>
3398 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3399</pre>
3400
3401<h5>Overview:</h5>
3402<p>
3403The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
3404</p>
3405
3406<h5>Arguments:</h5>
3407<p>
3408The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
3409be 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]3410and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3411type. The bit size of <tt>value</tt> must be larger than the bit size of
3412<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3413
3414<h5>Semantics:</h5>
3415<p>
3416The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3417and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
3418larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
3419It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3420
3421<h5>Example:</h5>
3422<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3423 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3424 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
3425 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3426</pre>
3427</div>
3428
3429<!-- _______________________________________________________________________ -->
3430<div class="doc_subsubsection">
3431 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
3432</div>
3433<div class="doc_text">
3434
3435<h5>Syntax:</h5>
3436<pre>
3437 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3438</pre>
3439
3440<h5>Overview:</h5>
3441<p>The '<tt>zext</tt>' instruction zero extends its operand to type
3442<tt>ty2</tt>.</p>
3443
3444
3445<h5>Arguments:</h5>
3446<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]3447<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3448also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3449<tt>value</tt> must be smaller than the bit size of the destination type,
3450<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3451
3452<h5>Semantics:</h5>
3453<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]3454bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3455
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]3456<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]3457
3458<h5>Example:</h5>
3459<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3460 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3461 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3462</pre>
3463</div>
3464
3465<!-- _______________________________________________________________________ -->
3466<div class="doc_subsubsection">
3467 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3468</div>
3469<div class="doc_text">
3470
3471<h5>Syntax:</h5>
3472<pre>
3473 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3474</pre>
3475
3476<h5>Overview:</h5>
3477<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3478
3479<h5>Arguments:</h5>
3480<p>
3481The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3482<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3483also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3484<tt>value</tt> must be smaller than the bit size of the destination type,
3485<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3486
3487<h5>Semantics:</h5>
3488<p>
3489The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3490bit (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]3491the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3492
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3493<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]3494
3495<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3496<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3497 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3498 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3499</pre>
3500</div>
3501
3502<!-- _______________________________________________________________________ -->
3503<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3504 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3505</div>
3506
3507<div class="doc_text">
3508
3509<h5>Syntax:</h5>
3510
3511<pre>
3512 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3513</pre>
3514
3515<h5>Overview:</h5>
3516<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3517<tt>ty2</tt>.</p>
3518
3519
3520<h5>Arguments:</h5>
3521<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3522 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3523cast it to. The size of <tt>value</tt> must be larger than the size of
3524<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3525<i>no-op cast</i>.</p>
3526
3527<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3528<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3529<a href="#t_floating">floating point</a> type to a smaller
3530<a href="#t_floating">floating point</a> type. If the value cannot fit within
3531the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3532
3533<h5>Example:</h5>
3534<pre>
3535 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3536 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3537</pre>
3538</div>
3539
3540<!-- _______________________________________________________________________ -->
3541<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3542 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3543</div>
3544<div class="doc_text">
3545
3546<h5>Syntax:</h5>
3547<pre>
3548 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3549</pre>
3550
3551<h5>Overview:</h5>
3552<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3553floating point value.</p>
3554
3555<h5>Arguments:</h5>
3556<p>The '<tt>fpext</tt>' instruction takes a
3557<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3558and a <a href="#t_floating">floating point</a> type to cast it to. The source
3559type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3560
3561<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3562<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3563<a href="#t_floating">floating point</a> type to a larger
3564<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3565used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3566<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]3567
3568<h5>Example:</h5>
3569<pre>
3570 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3571 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3572</pre>
3573</div>
3574
3575<!-- _______________________________________________________________________ -->
3576<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]3577 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3578</div>
3579<div class="doc_text">
3580
3581<h5>Syntax:</h5>
3582<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3583 &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]3584</pre>
3585
3586<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3587<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3588unsigned integer equivalent of type <tt>ty2</tt>.
3589</p>
3590
3591<h5>Arguments:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3592<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]3593scalar or vector <a href="#t_floating">floating point</a> value, and a type
3594to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3595type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3596vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3597
3598<h5>Semantics:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3599<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3600<a href="#t_floating">floating point</a> operand into the nearest (rounding
3601towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3602the results are undefined.</p>
3603
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3604<h5>Example:</h5>
3605<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3606 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3607 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3608 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3609</pre>
3610</div>
3611
3612<!-- _______________________________________________________________________ -->
3613<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3614 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3615</div>
3616<div class="doc_text">
3617
3618<h5>Syntax:</h5>
3619<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3620 &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]3621</pre>
3622
3623<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3624<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3625<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]3626</p>
3627
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3628<h5>Arguments:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3629<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]3630scalar or vector <a href="#t_floating">floating point</a> value, and a type
3631to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3632type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3633vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3634
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3635<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3636<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3637<a href="#t_floating">floating point</a> operand into the nearest (rounding
3638towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3639the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3640
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3641<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3642<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3643 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3644 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3645 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3646</pre>
3647</div>
3648
3649<!-- _______________________________________________________________________ -->
3650<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3651 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3652</div>
3653<div class="doc_text">
3654
3655<h5>Syntax:</h5>
3656<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3657 &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]3658</pre>
3659
3660<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3661<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3662integer and converts that value to the <tt>ty2</tt> type.</p>
3663
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3664<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3665<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3666scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3667to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3668type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3669floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3670
3671<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3672<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3673integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3674the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3675
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3676<h5>Example:</h5>
3677<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3678 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3679 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3680</pre>
3681</div>
3682
3683<!-- _______________________________________________________________________ -->
3684<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3685 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3686</div>
3687<div class="doc_text">
3688
3689<h5>Syntax:</h5>
3690<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3691 &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]3692</pre>
3693
3694<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3695<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3696integer and converts that value to the <tt>ty2</tt> type.</p>
3697
3698<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3699<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3700scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3701to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3702type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3703floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3704
3705<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3706<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3707integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3708the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3709
3710<h5>Example:</h5>
3711<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3712 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3713 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3714</pre>
3715</div>
3716
3717<!-- _______________________________________________________________________ -->
3718<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3719 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3720</div>
3721<div class="doc_text">
3722
3723<h5>Syntax:</h5>
3724<pre>
3725 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3726</pre>
3727
3728<h5>Overview:</h5>
3729<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3730the integer type <tt>ty2</tt>.</p>
3731
3732<h5>Arguments:</h5>
3733<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3734must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3735<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
3736
3737<h5>Semantics:</h5>
3738<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3739<tt>ty2</tt> by interpreting the pointer value as an integer and either
3740truncating or zero extending that value to the size of the integer type. If
3741<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3742<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]3743are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3744change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3745
3746<h5>Example:</h5>
3747<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3748 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3749 %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]3750</pre>
3751</div>
3752
3753<!-- _______________________________________________________________________ -->
3754<div class="doc_subsubsection">
3755 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3756</div>
3757<div class="doc_text">
3758
3759<h5>Syntax:</h5>
3760<pre>
3761 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3762</pre>
3763
3764<h5>Overview:</h5>
3765<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
3766a pointer type, <tt>ty2</tt>.</p>
3767
3768<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3769<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3770value to cast, and a type to cast it to, which must be a
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]3771<a href="#t_pointer">pointer</a> type.
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3772
3773<h5>Semantics:</h5>
3774<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
3775<tt>ty2</tt> by applying either a zero extension or a truncation depending on
3776the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
3777size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
3778the size of a pointer then a zero extension is done. If they are the same size,
3779nothing is done (<i>no-op cast</i>).</p>
3780
3781<h5>Example:</h5>
3782<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3783 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
3784 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
3785 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3786</pre>
3787</div>
3788
3789<!-- _______________________________________________________________________ -->
3790<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3791 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3792</div>
3793<div class="doc_text">
3794
3795<h5>Syntax:</h5>
3796<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3797 &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]3798</pre>
3799
3800<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3801
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3802<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3803<tt>ty2</tt> without changing any bits.</p>
3804
3805<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3806
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3807<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3808a first class value, and a type to cast it to, which must also be a <a
3809 href="#t_firstclass">first class</a> type. The bit sizes of <tt>value</tt>
Reid Spencer19b569f2007-01-09 20:08:58 +0000[diff] [blame]3810and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3811type is a pointer, the destination type must also be a pointer. This
3812instruction supports bitwise conversion of vectors to integers and to vectors
3813of other types (as long as they have the same size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3814
3815<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3816<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3817<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
3818this conversion. The conversion is done as if the <tt>value</tt> had been
3819stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
3820converted to other pointer types with this instruction. To convert pointers to
3821other types, use the <a href="#i_inttoptr">inttoptr</a> or
3822<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3823
3824<h5>Example:</h5>
3825<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3826 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3827 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
3828 %Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3829</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3830</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3831
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3832<!-- ======================================================================= -->
3833<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
3834<div class="doc_text">
3835<p>The instructions in this category are the "miscellaneous"
3836instructions, which defy better classification.</p>
3837</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3838
3839<!-- _______________________________________________________________________ -->
3840<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
3841</div>
3842<div class="doc_text">
3843<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3844<pre> &lt;result&gt; = icmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1}:result</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3845</pre>
3846<h5>Overview:</h5>
3847<p>The '<tt>icmp</tt>' instruction returns a boolean value based on comparison
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3848of its two integer or pointer operands.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3849<h5>Arguments:</h5>
3850<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3851the condition code indicating the kind of comparison to perform. It is not
3852a value, just a keyword. The possible condition code are:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3853<ol>
3854 <li><tt>eq</tt>: equal</li>
3855 <li><tt>ne</tt>: not equal </li>
3856 <li><tt>ugt</tt>: unsigned greater than</li>
3857 <li><tt>uge</tt>: unsigned greater or equal</li>
3858 <li><tt>ult</tt>: unsigned less than</li>
3859 <li><tt>ule</tt>: unsigned less or equal</li>
3860 <li><tt>sgt</tt>: signed greater than</li>
3861 <li><tt>sge</tt>: signed greater or equal</li>
3862 <li><tt>slt</tt>: signed less than</li>
3863 <li><tt>sle</tt>: signed less or equal</li>
3864</ol>
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3865<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Reid Spencer350f8aa2007-01-04 05:19:58 +0000[diff] [blame]3866<a href="#t_pointer">pointer</a> typed. They must also be identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3867<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3868<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]3869the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3870yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3871<ol>
3872 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
3873 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3874 </li>
3875 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
3876 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3877 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3878 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3879 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3880 <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]3881 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3882 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3883 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3884 <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]3885 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3886 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3887 <li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3888 <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]3889 <li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3890 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3891 <li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3892 <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]3893</ol>
3894<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3895values are compared as if they were integers.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3896
3897<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3898<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
3899 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
3900 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
3901 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
3902 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
3903 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3904</pre>
3905</div>
3906
3907<!-- _______________________________________________________________________ -->
3908<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
3909</div>
3910<div class="doc_text">
3911<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3912<pre> &lt;result&gt; = fcmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1}:result</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3913</pre>
3914<h5>Overview:</h5>
3915<p>The '<tt>fcmp</tt>' instruction returns a boolean value based on comparison
3916of its floating point operands.</p>
3917<h5>Arguments:</h5>
3918<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3919the condition code indicating the kind of comparison to perform. It is not
3920a value, just a keyword. The possible condition code are:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3921<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3922 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3923 <li><tt>oeq</tt>: ordered and equal</li>
3924 <li><tt>ogt</tt>: ordered and greater than </li>
3925 <li><tt>oge</tt>: ordered and greater than or equal</li>
3926 <li><tt>olt</tt>: ordered and less than </li>
3927 <li><tt>ole</tt>: ordered and less than or equal</li>
3928 <li><tt>one</tt>: ordered and not equal</li>
3929 <li><tt>ord</tt>: ordered (no nans)</li>
3930 <li><tt>ueq</tt>: unordered or equal</li>
3931 <li><tt>ugt</tt>: unordered or greater than </li>
3932 <li><tt>uge</tt>: unordered or greater than or equal</li>
3933 <li><tt>ult</tt>: unordered or less than </li>
3934 <li><tt>ule</tt>: unordered or less than or equal</li>
3935 <li><tt>une</tt>: unordered or not equal</li>
3936 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3937 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3938</ol>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3939<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer93a49852006-12-06 07:08:07 +0000[diff] [blame]3940<i>unordered</i> means that either operand may be a QNAN.</p>
Reid Spencer350f8aa2007-01-04 05:19:58 +0000[diff] [blame]3941<p>The <tt>val1</tt> and <tt>val2</tt> arguments must be
3942<a href="#t_floating">floating point</a> typed. They must have identical
3943types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3944<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3945<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]3946according to the condition code given as <tt>cond</tt>. The comparison performed
3947always yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3948<ol>
3949 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3950 <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]3951 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3952 <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]3953 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3954 <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]3955 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3956 <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]3957 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3958 <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]3959 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3960 <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]3961 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3962 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
3963 <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]3964 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3965 <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]3966 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3967 <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]3968 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3969 <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]3970 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3971 <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]3972 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3973 <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]3974 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3975 <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]3976 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
3977</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3978
3979<h5>Example:</h5>
3980<pre> &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
3981 &lt;result&gt; = icmp one float 4.0, 5.0 <i>; yields: result=true</i>
3982 &lt;result&gt; = icmp olt float 4.0, 5.0 <i>; yields: result=true</i>
3983 &lt;result&gt; = icmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
3984</pre>
3985</div>
3986
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3987<!-- _______________________________________________________________________ -->
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]3988<div class="doc_subsubsection">
3989 <a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
3990</div>
3991<div class="doc_text">
3992<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3993<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]3994</pre>
3995<h5>Overview:</h5>
3996<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
3997element-wise comparison of its two integer vector operands.</p>
3998<h5>Arguments:</h5>
3999<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
4000the condition code indicating the kind of comparison to perform. It is not
4001a value, just a keyword. The possible condition code are:
4002<ol>
4003 <li><tt>eq</tt>: equal</li>
4004 <li><tt>ne</tt>: not equal </li>
4005 <li><tt>ugt</tt>: unsigned greater than</li>
4006 <li><tt>uge</tt>: unsigned greater or equal</li>
4007 <li><tt>ult</tt>: unsigned less than</li>
4008 <li><tt>ule</tt>: unsigned less or equal</li>
4009 <li><tt>sgt</tt>: signed greater than</li>
4010 <li><tt>sge</tt>: signed greater or equal</li>
4011 <li><tt>slt</tt>: signed less than</li>
4012 <li><tt>sle</tt>: signed less or equal</li>
4013</ol>
4014<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
4015<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
4016<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4017<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4018according to the condition code given as <tt>cond</tt>. The comparison yields a
4019<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
4020identical type as the values being compared. The most significant bit in each
4021element is 1 if the element-wise comparison evaluates to true, and is 0
4022otherwise. All other bits of the result are undefined. The condition codes
4023are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
4024instruction</a>.
4025
4026<h5>Example:</h5>
4027<pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4028 &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>
4029 &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]4030</pre>
4031</div>
4032
4033<!-- _______________________________________________________________________ -->
4034<div class="doc_subsubsection">
4035 <a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
4036</div>
4037<div class="doc_text">
4038<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4039<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]4040<h5>Overview:</h5>
4041<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
4042element-wise comparison of its two floating point vector operands. The output
4043elements have the same width as the input elements.</p>
4044<h5>Arguments:</h5>
4045<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
4046the condition code indicating the kind of comparison to perform. It is not
4047a value, just a keyword. The possible condition code are:
4048<ol>
4049 <li><tt>false</tt>: no comparison, always returns false</li>
4050 <li><tt>oeq</tt>: ordered and equal</li>
4051 <li><tt>ogt</tt>: ordered and greater than </li>
4052 <li><tt>oge</tt>: ordered and greater than or equal</li>
4053 <li><tt>olt</tt>: ordered and less than </li>
4054 <li><tt>ole</tt>: ordered and less than or equal</li>
4055 <li><tt>one</tt>: ordered and not equal</li>
4056 <li><tt>ord</tt>: ordered (no nans)</li>
4057 <li><tt>ueq</tt>: unordered or equal</li>
4058 <li><tt>ugt</tt>: unordered or greater than </li>
4059 <li><tt>uge</tt>: unordered or greater than or equal</li>
4060 <li><tt>ult</tt>: unordered or less than </li>
4061 <li><tt>ule</tt>: unordered or less than or equal</li>
4062 <li><tt>une</tt>: unordered or not equal</li>
4063 <li><tt>uno</tt>: unordered (either nans)</li>
4064 <li><tt>true</tt>: no comparison, always returns true</li>
4065</ol>
4066<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
4067<a href="#t_floating">floating point</a> typed. They must also be identical
4068types.</p>
4069<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4070<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4071according to the condition code given as <tt>cond</tt>. The comparison yields a
4072<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
4073an identical number of elements as the values being compared, and each element
4074having identical with to the width of the floating point elements. The most
4075significant bit in each element is 1 if the element-wise comparison evaluates to
4076true, and is 0 otherwise. All other bits of the result are undefined. The
4077condition codes are evaluated identically to the
4078<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.
4079
4080<h5>Example:</h5>
4081<pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4082 &lt;result&gt; = vfcmp oeq &lt;2 x float&gt; &lt; float 4, float 0 &gt;, &lt; float 5, float 0 &gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0, i32 -1 &gt;</i>
4083 &lt;result&gt; = vfcmp ult &lt;2 x double&gt; &lt; double 1, double 2 &gt;, &lt; double 2, double 2&gt; <i>; yields: result=&lt;2 x i64&gt; &lt; i64 -1, i64 0 &gt;</i>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4084</pre>
4085</div>
4086
4087<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4088<div class="doc_subsubsection">
4089 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4090</div>
4091
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4092<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4093
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4094<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4095
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4096<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
4097<h5>Overview:</h5>
4098<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
4099the SSA graph representing the function.</p>
4100<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4101
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4102<p>The type of the incoming values is specified with the first type
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4103field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
4104as arguments, with one pair for each predecessor basic block of the
4105current block. Only values of <a href="#t_firstclass">first class</a>
4106type may be used as the value arguments to the PHI node. Only labels
4107may be used as the label arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4108
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4109<p>There must be no non-phi instructions between the start of a basic
4110block and the PHI instructions: i.e. PHI instructions must be first in
4111a basic block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4112
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4113<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4114
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4115<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
4116specified by the pair corresponding to the predecessor basic block that executed
4117just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4118
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4119<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4120<pre>
4121Loop: ; Infinite loop that counts from 0 on up...
4122 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4123 %nextindvar = add i32 %indvar, 1
4124 br label %Loop
4125</pre>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4126</div>
4127
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4128<!-- _______________________________________________________________________ -->
4129<div class="doc_subsubsection">
4130 <a name="i_select">'<tt>select</tt>' Instruction</a>
4131</div>
4132
4133<div class="doc_text">
4134
4135<h5>Syntax:</h5>
4136
4137<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4138 &lt;result&gt; = select i1 &lt;cond&gt;, &lt;ty&gt; &lt;val1&gt;, &lt;ty&gt; &lt;val2&gt; <i>; yields ty</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4139</pre>
4140
4141<h5>Overview:</h5>
4142
4143<p>
4144The '<tt>select</tt>' instruction is used to choose one value based on a
4145condition, without branching.
4146</p>
4147
4148
4149<h5>Arguments:</h5>
4150
4151<p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4152The '<tt>select</tt>' instruction requires an 'i1' value indicating the
4153condition, and two values of the same <a href="#t_firstclass">first class</a>
4154type. If the val1/val2 are vectors, the entire vectors are selected, not
4155individual elements.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4156</p>
4157
4158<h5>Semantics:</h5>
4159
4160<p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4161If the i1 condition evaluates is 1, the instruction returns the first
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4162value argument; otherwise, it returns the second value argument.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4163</p>
4164
4165<h5>Example:</h5>
4166
4167<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4168 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4169</pre>
4170</div>
4171
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]4172
4173<!-- _______________________________________________________________________ -->
4174<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4175 <a name="i_call">'<tt>call</tt>' Instruction</a>
4176</div>
4177
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4178<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4179
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4180<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4181<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4182 &lt;result&gt; = [tail] call [<a href="#callingconv">cconv</a>] &lt;ty&gt; [&lt;fnty&gt;*] &lt;fnptrval&gt;(&lt;param list&gt;)
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4183</pre>
4184
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4185<h5>Overview:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4186
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4187<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4188
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4189<h5>Arguments:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4190
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4191<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4192
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4193<ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4194 <li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4195 <p>The optional "tail" marker indicates whether the callee function accesses
4196 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4197 function call is eligible for tail call optimization. Note that calls may
4198 be marked "tail" even if they do not occur before a <a
4199 href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4200 </li>
4201 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4202 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4203 convention</a> the call should use. If none is specified, the call defaults
4204 to using C calling conventions.
4205 </li>
4206 <li>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4207 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
4208 the type of the return value. Functions that return no value are marked
4209 <tt><a href="#t_void">void</a></tt>.</p>
4210 </li>
4211 <li>
4212 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
4213 value being invoked. The argument types must match the types implied by
4214 this signature. This type can be omitted if the function is not varargs
4215 and if the function type does not return a pointer to a function.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4216 </li>
4217 <li>
4218 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4219 be invoked. In most cases, this is a direct function invocation, but
4220 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4221 to function value.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4222 </li>
4223 <li>
4224 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencera7e302a2005-05-01 22:22:57 +0000[diff] [blame]4225 function signature argument types. All arguments must be of
4226 <a href="#t_firstclass">first class</a> type. If the function signature
4227 indicates the function accepts a variable number of arguments, the extra
4228 arguments can be specified.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4229 </li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4230</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4231
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4232<h5>Semantics:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4233
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4234<p>The '<tt>call</tt>' instruction is used to cause control flow to
4235transfer to a specified function, with its incoming arguments bound to
4236the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
4237instruction in the called function, control flow continues with the
4238instruction after the function call, and the return value of the
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]4239function is bound to the result argument. If the callee returns multiple
4240values then the return values of the function are only accessible through
4241the '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4242
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4243<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4244
4245<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4246 %retval = call i32 @test(i32 %argc)
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]4247 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4248 %X = tail call i32 @foo() <i>; yields i32</i>
4249 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4250 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]4251
4252 %struct.A = type { i32, i8 }
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]4253 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
4254 %gr = getresult %struct.A %r, 0 <i>; yields i32</i>
4255 %gr1 = getresult %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4256</pre>
4257
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4258</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4259
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4260<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4261<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]4262 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4263</div>
4264
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4265<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4266
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4267<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4268
4269<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4270 &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]4271</pre>
4272
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4273<h5>Overview:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4274
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4275<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4276the "variable argument" area of a function call. It is used to implement the
4277<tt>va_arg</tt> macro in C.</p>
4278
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4279<h5>Arguments:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4280
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4281<p>This instruction takes a <tt>va_list*</tt> value and the type of
4282the argument. It returns a value of the specified argument type and
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4283increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4284actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4285
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4286<h5>Semantics:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4287
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4288<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
4289type from the specified <tt>va_list</tt> and causes the
4290<tt>va_list</tt> to point to the next argument. For more information,
4291see the variable argument handling <a href="#int_varargs">Intrinsic
4292Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4293
4294<p>It is legal for this instruction to be called in a function which does not
4295take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4296function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4297
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4298<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4299href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4300argument.</p>
4301
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4302<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4303
4304<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4305
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4306</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4307
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]4308<!-- _______________________________________________________________________ -->
4309<div class="doc_subsubsection">
4310 <a name="i_getresult">'<tt>getresult</tt>' Instruction</a>
4311</div>
4312
4313<div class="doc_text">
4314
4315<h5>Syntax:</h5>
4316<pre>
Chris Lattner45c5e8b2008-03-21 17:20:51 +0000[diff] [blame]4317 &lt;resultval&gt; = getresult &lt;type&gt; &lt;retval&gt;, &lt;index&gt;
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]4318</pre>
Chris Lattner45c5e8b2008-03-21 17:20:51 +0000[diff] [blame]4319
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]4320<h5>Overview:</h5>
4321
4322<p> The '<tt>getresult</tt>' instruction is used to extract individual values
Chris Lattner45c5e8b2008-03-21 17:20:51 +0000[diff] [blame]4323from a '<tt><a href="#i_call">call</a></tt>'
4324or '<tt><a href="#i_invoke">invoke</a></tt>' instruction that returns multiple
4325results.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]4326
4327<h5>Arguments:</h5>
4328
Chris Lattner45c5e8b2008-03-21 17:20:51 +0000[diff] [blame]4329<p>The '<tt>getresult</tt>' instruction takes a call or invoke value as its
Chris Lattner1c406d72008-04-23 04:06:52 +0000[diff] [blame]4330first argument, or an undef value. The value must have <a
4331href="#t_struct">structure type</a>. The second argument is a constant
4332unsigned index value which must be in range for the number of values returned
4333by the call.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]4334
4335<h5>Semantics:</h5>
4336
Chris Lattner45c5e8b2008-03-21 17:20:51 +0000[diff] [blame]4337<p>The '<tt>getresult</tt>' instruction extracts the element identified by
4338'<tt>index</tt>' from the aggregate value.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]4339
4340<h5>Example:</h5>
4341
4342<pre>
4343 %struct.A = type { i32, i8 }
4344
4345 %r = call %struct.A @foo()
Chris Lattner45c5e8b2008-03-21 17:20:51 +0000[diff] [blame]4346 %gr = getresult %struct.A %r, 0 <i>; yields i32:%gr</i>
4347 %gr1 = getresult %struct.A %r, 1 <i>; yields i8:%gr1</i>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]4348 add i32 %gr, 42
4349 add i8 %gr1, 41
4350</pre>
4351
4352</div>
4353
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4354<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4355<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4356<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4357
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4358<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4359
4360<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4361well known names and semantics and are required to follow certain restrictions.
4362Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4363language that does not require changing all of the transformations in LLVM when
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]4364adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4365
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4366<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4367prefix is reserved in LLVM for intrinsic names; thus, function names may not
4368begin with this prefix. Intrinsic functions must always be external functions:
4369you cannot define the body of intrinsic functions. Intrinsic functions may
4370only be used in call or invoke instructions: it is illegal to take the address
4371of an intrinsic function. Additionally, because intrinsic functions are part
4372of the LLVM language, it is required if any are added that they be documented
4373here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4374
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4375<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
4376a family of functions that perform the same operation but on different data
4377types. Because LLVM can represent over 8 million different integer types,
4378overloading is used commonly to allow an intrinsic function to operate on any
4379integer type. One or more of the argument types or the result type can be
4380overloaded to accept any integer type. Argument types may also be defined as
4381exactly matching a previous argument's type or the result type. This allows an
4382intrinsic function which accepts multiple arguments, but needs all of them to
4383be of the same type, to only be overloaded with respect to a single argument or
4384the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4385
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4386<p>Overloaded intrinsics will have the names of its overloaded argument types
4387encoded into its function name, each preceded by a period. Only those types
4388which are overloaded result in a name suffix. Arguments whose type is matched
4389against another type do not. For example, the <tt>llvm.ctpop</tt> function can
4390take an integer of any width and returns an integer of exactly the same integer
4391width. This leads to a family of functions such as
4392<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
4393Only one type, the return type, is overloaded, and only one type suffix is
4394required. Because the argument's type is matched against the return type, it
4395does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4396
4397<p>To learn how to add an intrinsic function, please see the
4398<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4399</p>
4400
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4401</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4402
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4403<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4404<div class="doc_subsection">
4405 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
4406</div>
4407
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4408<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4409
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4410<p>Variable argument support is defined in LLVM with the <a
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]4411 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4412intrinsic functions. These functions are related to the similarly
4413named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4414
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4415<p>All of these functions operate on arguments that use a
4416target-specific value type "<tt>va_list</tt>". The LLVM assembly
4417language reference manual does not define what this type is, so all
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4418transformations should be prepared to handle these functions regardless of
4419the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4420
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]4421<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]4422instruction and the variable argument handling intrinsic functions are
4423used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4424
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4425<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4426<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4427define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4428 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4429 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4430 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4431 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4432
4433 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4434 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4435
4436 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4437 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4438 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4439 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4440 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4441
4442 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4443 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4444 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4445}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4446
4447declare void @llvm.va_start(i8*)
4448declare void @llvm.va_copy(i8*, i8*)
4449declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4450</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4451</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4452
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4453</div>
4454
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4455<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4456<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4457 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4458</div>
4459
4460
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4461<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4462<h5>Syntax:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4463<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4464<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4465<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
4466<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
4467href="#i_va_arg">va_arg</a></tt>.</p>
4468
4469<h5>Arguments:</h5>
4470
4471<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
4472
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4473<h5>Semantics:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4474
4475<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
4476macro available in C. In a target-dependent way, it initializes the
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4477<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]4478<tt>va_arg</tt> will produce the first variable argument passed to the function.
4479Unlike 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]4480last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4481
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4482</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4483
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4484<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4485<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4486 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4487</div>
4488
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4489<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4490<h5>Syntax:</h5>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4491<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4492<h5>Overview:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4493
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4494<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4495which 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]4496or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4497
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4498<h5>Arguments:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4499
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4500<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]4501
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4502<h5>Semantics:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4503
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4504<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]4505macro available in C. In a target-dependent way, it destroys the
4506<tt>va_list</tt> element to which the argument points. Calls to <a
4507href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
4508<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
4509<tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4510
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4511</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4512
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4513<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4514<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4515 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4516</div>
4517
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4518<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4519
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4520<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4521
4522<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4523 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4524</pre>
4525
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4526<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4527
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4528<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
4529from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4530
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4531<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4532
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4533<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]4534The 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]4535
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4536
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4537<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4538
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4539<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
4540macro available in C. In a target-dependent way, it copies the source
4541<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
4542intrinsic is necessary because the <tt><a href="#int_va_start">
4543llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
4544example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4545
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4546</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4547
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4548<!-- ======================================================================= -->
4549<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4550 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
4551</div>
4552
4553<div class="doc_text">
4554
4555<p>
4556LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]4557Collection</a> (GC) requires the implementation and generation of these
4558intrinsics.
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4559These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4560stack</a>, as well as garbage collector implementations that require <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4561href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4562Front-ends for type-safe garbage collected languages should generate these
4563intrinsics to make use of the LLVM garbage collectors. For more details, see <a
4564href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
4565</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]4566
4567<p>The garbage collection intrinsics only operate on objects in the generic
4568 address space (address space zero).</p>
4569
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4570</div>
4571
4572<!-- _______________________________________________________________________ -->
4573<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4574 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4575</div>
4576
4577<div class="doc_text">
4578
4579<h5>Syntax:</h5>
4580
4581<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4582 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4583</pre>
4584
4585<h5>Overview:</h5>
4586
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]4587<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]4588the code generator, and allows some metadata to be associated with it.</p>
4589
4590<h5>Arguments:</h5>
4591
4592<p>The first argument specifies the address of a stack object that contains the
4593root pointer. The second pointer (which must be either a constant or a global
4594value address) contains the meta-data to be associated with the root.</p>
4595
4596<h5>Semantics:</h5>
4597
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]4598<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]4599location. At compile-time, the code generator generates information to allow
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4600the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
4601intrinsic may only be used in a function which <a href="#gc">specifies a GC
4602algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4603
4604</div>
4605
4606
4607<!-- _______________________________________________________________________ -->
4608<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4609 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4610</div>
4611
4612<div class="doc_text">
4613
4614<h5>Syntax:</h5>
4615
4616<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4617 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4618</pre>
4619
4620<h5>Overview:</h5>
4621
4622<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4623locations, allowing garbage collector implementations that require read
4624barriers.</p>
4625
4626<h5>Arguments:</h5>
4627
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4628<p>The second argument is the address to read from, which should be an address
4629allocated from the garbage collector. The first object is a pointer to the
4630start of the referenced object, if needed by the language runtime (otherwise
4631null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4632
4633<h5>Semantics:</h5>
4634
4635<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4636instruction, but may be replaced with substantially more complex code by the
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4637garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
4638may only be used in a function which <a href="#gc">specifies a GC
4639algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4640
4641</div>
4642
4643
4644<!-- _______________________________________________________________________ -->
4645<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4646 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4647</div>
4648
4649<div class="doc_text">
4650
4651<h5>Syntax:</h5>
4652
4653<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4654 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4655</pre>
4656
4657<h5>Overview:</h5>
4658
4659<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4660locations, allowing garbage collector implementations that require write
4661barriers (such as generational or reference counting collectors).</p>
4662
4663<h5>Arguments:</h5>
4664
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4665<p>The first argument is the reference to store, the second is the start of the
4666object to store it to, and the third is the address of the field of Obj to
4667store to. If the runtime does not require a pointer to the object, Obj may be
4668null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4669
4670<h5>Semantics:</h5>
4671
4672<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4673instruction, but may be replaced with substantially more complex code by the
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4674garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
4675may only be used in a function which <a href="#gc">specifies a GC
4676algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4677
4678</div>
4679
4680
4681
4682<!-- ======================================================================= -->
4683<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4684 <a name="int_codegen">Code Generator Intrinsics</a>
4685</div>
4686
4687<div class="doc_text">
4688<p>
4689These intrinsics are provided by LLVM to expose special features that may only
4690be implemented with code generator support.
4691</p>
4692
4693</div>
4694
4695<!-- _______________________________________________________________________ -->
4696<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4697 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4698</div>
4699
4700<div class="doc_text">
4701
4702<h5>Syntax:</h5>
4703<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4704 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4705</pre>
4706
4707<h5>Overview:</h5>
4708
4709<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4710The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4711target-specific value indicating the return address of the current function
4712or one of its callers.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4713</p>
4714
4715<h5>Arguments:</h5>
4716
4717<p>
4718The argument to this intrinsic indicates which function to return the address
4719for. Zero indicates the calling function, one indicates its caller, etc. The
4720argument is <b>required</b> to be a constant integer value.
4721</p>
4722
4723<h5>Semantics:</h5>
4724
4725<p>
4726The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4727the return address of the specified call frame, or zero if it cannot be
4728identified. The value returned by this intrinsic is likely to be incorrect or 0
4729for arguments other than zero, so it should only be used for debugging purposes.
4730</p>
4731
4732<p>
4733Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4734aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4735source-language caller.
4736</p>
4737</div>
4738
4739
4740<!-- _______________________________________________________________________ -->
4741<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4742 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4743</div>
4744
4745<div class="doc_text">
4746
4747<h5>Syntax:</h5>
4748<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4749 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4750</pre>
4751
4752<h5>Overview:</h5>
4753
4754<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4755The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
4756target-specific frame pointer value for the specified stack frame.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4757</p>
4758
4759<h5>Arguments:</h5>
4760
4761<p>
4762The argument to this intrinsic indicates which function to return the frame
4763pointer for. Zero indicates the calling function, one indicates its caller,
4764etc. The argument is <b>required</b> to be a constant integer value.
4765</p>
4766
4767<h5>Semantics:</h5>
4768
4769<p>
4770The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
4771the frame address of the specified call frame, or zero if it cannot be
4772identified. The value returned by this intrinsic is likely to be incorrect or 0
4773for arguments other than zero, so it should only be used for debugging purposes.
4774</p>
4775
4776<p>
4777Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4778aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4779source-language caller.
4780</p>
4781</div>
4782
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4783<!-- _______________________________________________________________________ -->
4784<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4785 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4786</div>
4787
4788<div class="doc_text">
4789
4790<h5>Syntax:</h5>
4791<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4792 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4793</pre>
4794
4795<h5>Overview:</h5>
4796
4797<p>
4798The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4799the function stack, for use with <a href="#int_stackrestore">
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4800<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
4801features like scoped automatic variable sized arrays in C99.
4802</p>
4803
4804<h5>Semantics:</h5>
4805
4806<p>
4807This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4808href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4809<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
4810<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
4811state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
4812practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
4813that were allocated after the <tt>llvm.stacksave</tt> was executed.
4814</p>
4815
4816</div>
4817
4818<!-- _______________________________________________________________________ -->
4819<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4820 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4821</div>
4822
4823<div class="doc_text">
4824
4825<h5>Syntax:</h5>
4826<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4827 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4828</pre>
4829
4830<h5>Overview:</h5>
4831
4832<p>
4833The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
4834the function stack to the state it was in when the corresponding <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4835href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4836useful for implementing language features like scoped automatic variable sized
4837arrays in C99.
4838</p>
4839
4840<h5>Semantics:</h5>
4841
4842<p>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4843See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4844</p>
4845
4846</div>
4847
4848
4849<!-- _______________________________________________________________________ -->
4850<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4851 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4852</div>
4853
4854<div class="doc_text">
4855
4856<h5>Syntax:</h5>
4857<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4858 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]4859</pre>
4860
4861<h5>Overview:</h5>
4862
4863
4864<p>
4865The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4866a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
4867no
4868effect on the behavior of the program but can change its performance
Chris Lattner2a615362005-02-28 19:47:14 +0000[diff] [blame]4869characteristics.
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4870</p>
4871
4872<h5>Arguments:</h5>
4873
4874<p>
4875<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
4876determining if the fetch should be for a read (0) or write (1), and
4877<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattneraeffb4a2005-03-07 20:31:38 +0000[diff] [blame]4878locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4879<tt>locality</tt> arguments must be constant integers.
4880</p>
4881
4882<h5>Semantics:</h5>
4883
4884<p>
4885This intrinsic does not modify the behavior of the program. In particular,
4886prefetches cannot trap and do not produce a value. On targets that support this
4887intrinsic, the prefetch can provide hints to the processor cache for better
4888performance.
4889</p>
4890
4891</div>
4892
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4893<!-- _______________________________________________________________________ -->
4894<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4895 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4896</div>
4897
4898<div class="doc_text">
4899
4900<h5>Syntax:</h5>
4901<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4902 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4903</pre>
4904
4905<h5>Overview:</h5>
4906
4907
4908<p>
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4909The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]4910(PC) in a region of
4911code to simulators and other tools. The method is target specific, but it is
4912expected that the marker will use exported symbols to transmit the PC of the
4913marker.
4914The marker makes no guarantees that it will remain with any specific instruction
4915after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb3e7afd2006-03-24 07:16:10 +0000[diff] [blame]4916optimizations. The intended use is to be inserted after optimizations to allow
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4917correlations of simulation runs.
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4918</p>
4919
4920<h5>Arguments:</h5>
4921
4922<p>
4923<tt>id</tt> is a numerical id identifying the marker.
4924</p>
4925
4926<h5>Semantics:</h5>
4927
4928<p>
4929This intrinsic does not modify the behavior of the program. Backends that do not
4930support this intrinisic may ignore it.
4931</p>
4932
4933</div>
4934
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]4935<!-- _______________________________________________________________________ -->
4936<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4937 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]4938</div>
4939
4940<div class="doc_text">
4941
4942<h5>Syntax:</h5>
4943<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4944 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]4945</pre>
4946
4947<h5>Overview:</h5>
4948
4949
4950<p>
4951The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
4952counter register (or similar low latency, high accuracy clocks) on those targets
4953that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
4954As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
4955should only be used for small timings.
4956</p>
4957
4958<h5>Semantics:</h5>
4959
4960<p>
4961When directly supported, reading the cycle counter should not modify any memory.
4962Implementations are allowed to either return a application specific value or a
4963system wide value. On backends without support, this is lowered to a constant 0.
4964</p>
4965
4966</div>
4967
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4968<!-- ======================================================================= -->
4969<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4970 <a name="int_libc">Standard C Library Intrinsics</a>
4971</div>
4972
4973<div class="doc_text">
4974<p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4975LLVM provides intrinsics for a few important standard C library functions.
4976These intrinsics allow source-language front-ends to pass information about the
4977alignment of the pointer arguments to the code generator, providing opportunity
4978for more efficient code generation.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4979</p>
4980
4981</div>
4982
4983<!-- _______________________________________________________________________ -->
4984<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4985 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4986</div>
4987
4988<div class="doc_text">
4989
4990<h5>Syntax:</h5>
4991<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4992 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4993 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4994 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4995 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4996</pre>
4997
4998<h5>Overview:</h5>
4999
5000<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5001The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5002location to the destination location.
5003</p>
5004
5005<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5006Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5007intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5008</p>
5009
5010<h5>Arguments:</h5>
5011
5012<p>
5013The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5014the source. The third argument is an integer argument
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5015specifying the number of bytes to copy, and the fourth argument is the alignment
5016of the source and destination locations.
5017</p>
5018
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5019<p>
5020If 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]5021the caller guarantees that both the source and destination pointers are aligned
5022to that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5023</p>
5024
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5025<h5>Semantics:</h5>
5026
5027<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5028The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5029location to the destination location, which are not allowed to overlap. It
5030copies "len" bytes of memory over. If the argument is known to be aligned to
5031some boundary, this can be specified as the fourth argument, otherwise it should
5032be set to 0 or 1.
5033</p>
5034</div>
5035
5036
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5037<!-- _______________________________________________________________________ -->
5038<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5039 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5040</div>
5041
5042<div class="doc_text">
5043
5044<h5>Syntax:</h5>
5045<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5046 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5047 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5048 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5049 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5050</pre>
5051
5052<h5>Overview:</h5>
5053
5054<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5055The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
5056location to the destination location. It is similar to the
Chris Lattner4b2cbcf2008-01-06 19:51:52 +0000[diff] [blame]5057'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5058</p>
5059
5060<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5061Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5062intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5063</p>
5064
5065<h5>Arguments:</h5>
5066
5067<p>
5068The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5069the source. The third argument is an integer argument
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5070specifying the number of bytes to copy, and the fourth argument is the alignment
5071of the source and destination locations.
5072</p>
5073
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5074<p>
5075If 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]5076the caller guarantees that the source and destination pointers are aligned to
5077that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5078</p>
5079
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5080<h5>Semantics:</h5>
5081
5082<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5083The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5084location to the destination location, which may overlap. It
5085copies "len" bytes of memory over. If the argument is known to be aligned to
5086some boundary, this can be specified as the fourth argument, otherwise it should
5087be set to 0 or 1.
5088</p>
5089</div>
5090
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5091
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5092<!-- _______________________________________________________________________ -->
5093<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5094 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5095</div>
5096
5097<div class="doc_text">
5098
5099<h5>Syntax:</h5>
5100<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5101 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5102 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5103 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5104 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5105</pre>
5106
5107<h5>Overview:</h5>
5108
5109<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5110The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5111byte value.
5112</p>
5113
5114<p>
5115Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
5116does not return a value, and takes an extra alignment argument.
5117</p>
5118
5119<h5>Arguments:</h5>
5120
5121<p>
5122The first argument is a pointer to the destination to fill, the second is the
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5123byte value to fill it with, the third argument is an integer
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5124argument specifying the number of bytes to fill, and the fourth argument is the
5125known alignment of destination location.
5126</p>
5127
5128<p>
5129If 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]5130the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5131</p>
5132
5133<h5>Semantics:</h5>
5134
5135<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5136The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
5137the
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5138destination location. If the argument is known to be aligned to some boundary,
5139this can be specified as the fourth argument, otherwise it should be set to 0 or
51401.
5141</p>
5142</div>
5143
5144
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5145<!-- _______________________________________________________________________ -->
5146<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5147 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5148</div>
5149
5150<div class="doc_text">
5151
5152<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5153<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]5154floating point or vector of floating point type. Not all targets support all
5155types however.
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5156<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5157 declare float @llvm.sqrt.f32(float %Val)
5158 declare double @llvm.sqrt.f64(double %Val)
5159 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5160 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5161 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5162</pre>
5163
5164<h5>Overview:</h5>
5165
5166<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5167The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5168returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5169<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner103e2d72008-01-29 07:00:44 +0000[diff] [blame]5170negative numbers other than -0.0 (which allows for better optimization, because
5171there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
5172defined to return -0.0 like IEEE sqrt.
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5173</p>
5174
5175<h5>Arguments:</h5>
5176
5177<p>
5178The argument and return value are floating point numbers of the same type.
5179</p>
5180
5181<h5>Semantics:</h5>
5182
5183<p>
Dan Gohmand6257fe2007-07-16 14:37:41 +0000[diff] [blame]5184This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5185floating point number.
5186</p>
5187</div>
5188
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5189<!-- _______________________________________________________________________ -->
5190<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5191 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5192</div>
5193
5194<div class="doc_text">
5195
5196<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5197<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]5198floating point or vector of floating point type. Not all targets support all
5199types however.
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5200<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5201 declare float @llvm.powi.f32(float %Val, i32 %power)
5202 declare double @llvm.powi.f64(double %Val, i32 %power)
5203 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5204 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5205 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5206</pre>
5207
5208<h5>Overview:</h5>
5209
5210<p>
5211The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5212specified (positive or negative) power. The order of evaluation of
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5213multiplications is not defined. When a vector of floating point type is
5214used, the second argument remains a scalar integer value.
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5215</p>
5216
5217<h5>Arguments:</h5>
5218
5219<p>
5220The second argument is an integer power, and the first is a value to raise to
5221that power.
5222</p>
5223
5224<h5>Semantics:</h5>
5225
5226<p>
5227This function returns the first value raised to the second power with an
5228unspecified sequence of rounding operations.</p>
5229</div>
5230
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5231<!-- _______________________________________________________________________ -->
5232<div class="doc_subsubsection">
5233 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5234</div>
5235
5236<div class="doc_text">
5237
5238<h5>Syntax:</h5>
5239<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5240floating point or vector of floating point type. Not all targets support all
5241types however.
5242<pre>
5243 declare float @llvm.sin.f32(float %Val)
5244 declare double @llvm.sin.f64(double %Val)
5245 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5246 declare fp128 @llvm.sin.f128(fp128 %Val)
5247 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5248</pre>
5249
5250<h5>Overview:</h5>
5251
5252<p>
5253The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
5254</p>
5255
5256<h5>Arguments:</h5>
5257
5258<p>
5259The argument and return value are floating point numbers of the same type.
5260</p>
5261
5262<h5>Semantics:</h5>
5263
5264<p>
5265This function returns the sine of the specified operand, returning the
5266same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5267conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5268</div>
5269
5270<!-- _______________________________________________________________________ -->
5271<div class="doc_subsubsection">
5272 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5273</div>
5274
5275<div class="doc_text">
5276
5277<h5>Syntax:</h5>
5278<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5279floating point or vector of floating point type. Not all targets support all
5280types however.
5281<pre>
5282 declare float @llvm.cos.f32(float %Val)
5283 declare double @llvm.cos.f64(double %Val)
5284 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5285 declare fp128 @llvm.cos.f128(fp128 %Val)
5286 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5287</pre>
5288
5289<h5>Overview:</h5>
5290
5291<p>
5292The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
5293</p>
5294
5295<h5>Arguments:</h5>
5296
5297<p>
5298The argument and return value are floating point numbers of the same type.
5299</p>
5300
5301<h5>Semantics:</h5>
5302
5303<p>
5304This function returns the cosine of the specified operand, returning the
5305same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5306conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5307</div>
5308
5309<!-- _______________________________________________________________________ -->
5310<div class="doc_subsubsection">
5311 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5312</div>
5313
5314<div class="doc_text">
5315
5316<h5>Syntax:</h5>
5317<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5318floating point or vector of floating point type. Not all targets support all
5319types however.
5320<pre>
5321 declare float @llvm.pow.f32(float %Val, float %Power)
5322 declare double @llvm.pow.f64(double %Val, double %Power)
5323 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5324 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5325 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5326</pre>
5327
5328<h5>Overview:</h5>
5329
5330<p>
5331The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5332specified (positive or negative) power.
5333</p>
5334
5335<h5>Arguments:</h5>
5336
5337<p>
5338The second argument is a floating point power, and the first is a value to
5339raise to that power.
5340</p>
5341
5342<h5>Semantics:</h5>
5343
5344<p>
5345This function returns the first value raised to the second power,
5346returning the
5347same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5348conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5349</div>
5350
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5351
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5352<!-- ======================================================================= -->
5353<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5354 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5355</div>
5356
5357<div class="doc_text">
5358<p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5359LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5360These allow efficient code generation for some algorithms.
5361</p>
5362
5363</div>
5364
5365<!-- _______________________________________________________________________ -->
5366<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5367 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5368</div>
5369
5370<div class="doc_text">
5371
5372<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5373<p>This is an overloaded intrinsic function. You can use bswap on any integer
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5374type that is an even number of bytes (i.e. BitWidth % 16 == 0).
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5375<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5376 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5377 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5378 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5379</pre>
5380
5381<h5>Overview:</h5>
5382
5383<p>
Reid Spencer338ea092007-04-02 02:25:19 +0000[diff] [blame]5384The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5385values with an even number of bytes (positive multiple of 16 bits). These are
5386useful for performing operations on data that is not in the target's native
5387byte order.
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5388</p>
5389
5390<h5>Semantics:</h5>
5391
5392<p>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5393The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5394and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
5395intrinsic returns an i32 value that has the four bytes of the input i32
5396swapped, 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]5397i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
5398<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5399additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5400</p>
5401
5402</div>
5403
5404<!-- _______________________________________________________________________ -->
5405<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5406 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5407</div>
5408
5409<div class="doc_text">
5410
5411<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5412<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
5413width. Not all targets support all bit widths however.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5414<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5415 declare i8 @llvm.ctpop.i8 (i8 &lt;src&gt;)
5416 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5417 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5418 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5419 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5420</pre>
5421
5422<h5>Overview:</h5>
5423
5424<p>
Chris Lattnerec6cb612006-01-16 22:38:59 +0000[diff] [blame]5425The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
5426value.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5427</p>
5428
5429<h5>Arguments:</h5>
5430
5431<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]5432The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5433integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5434</p>
5435
5436<h5>Semantics:</h5>
5437
5438<p>
5439The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
5440</p>
5441</div>
5442
5443<!-- _______________________________________________________________________ -->
5444<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5445 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5446</div>
5447
5448<div class="doc_text">
5449
5450<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5451<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
5452integer bit width. Not all targets support all bit widths however.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5453<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5454 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5455 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5456 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5457 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5458 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5459</pre>
5460
5461<h5>Overview:</h5>
5462
5463<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5464The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5465leading zeros in a variable.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5466</p>
5467
5468<h5>Arguments:</h5>
5469
5470<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]5471The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5472integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5473</p>
5474
5475<h5>Semantics:</h5>
5476
5477<p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5478The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
5479in 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]5480of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5481</p>
5482</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5483
5484
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5485
5486<!-- _______________________________________________________________________ -->
5487<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5488 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +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 <tt>llvm.cttz</tt> on any
5495integer bit width. Not all targets support all bit widths however.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5496<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5497 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5498 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5499 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5500 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5501 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5502</pre>
5503
5504<h5>Overview:</h5>
5505
5506<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5507The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5508trailing zeros.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5509</p>
5510
5511<h5>Arguments:</h5>
5512
5513<p>
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.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5516</p>
5517
5518<h5>Semantics:</h5>
5519
5520<p>
5521The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
5522in a variable. If the src == 0 then the result is the size in bits of the type
5523of src. For example, <tt>llvm.cttz(2) = 1</tt>.
5524</p>
5525</div>
5526
Reid Spencer497d93e2007-04-01 08:27:01 +0000[diff] [blame]5527<!-- _______________________________________________________________________ -->
5528<div class="doc_subsubsection">
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5529 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5530</div>
5531
5532<div class="doc_text">
5533
5534<h5>Syntax:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5535<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5536on any integer bit width.
5537<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5538 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
5539 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5540</pre>
5541
5542<h5>Overview:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5543<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5544range of bits from an integer value and returns them in the same bit width as
5545the original value.</p>
5546
5547<h5>Arguments:</h5>
5548<p>The first argument, <tt>%val</tt> and the result may be integer types of
5549any bit width but they must have the same bit width. The second and third
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5550arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5551
5552<h5>Semantics:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5553<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5554of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
5555<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
5556operates in forward mode.</p>
5557<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
5558right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5559only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
5560<ol>
5561 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
5562 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
5563 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
5564 to determine the number of bits to retain.</li>
5565 <li>A mask of the retained bits is created by shifting a -1 value.</li>
5566 <li>The mask is ANDed with <tt>%val</tt> to produce the result.
5567</ol>
Reid Spencerd6a85b52007-05-14 16:14:57 +0000[diff] [blame]5568<p>In reverse mode, a similar computation is made except that the bits are
5569returned in the reverse order. So, for example, if <tt>X</tt> has the value
5570<tt>i16 0x0ACF (101011001111)</tt> and we apply
5571<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
5572<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5573</div>
5574
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5575<div class="doc_subsubsection">
5576 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
5577</div>
5578
5579<div class="doc_text">
5580
5581<h5>Syntax:</h5>
5582<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
5583on any integer bit width.
5584<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5585 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
5586 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]5587</pre>
5588
5589<h5>Overview:</h5>
5590<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
5591of bits in an integer value with another integer value. It returns the integer
5592with the replaced bits.</p>
5593
5594<h5>Arguments:</h5>
5595<p>The first argument, <tt>%val</tt> and the result may be integer types of
5596any bit width but they must have the same bit width. <tt>%val</tt> is the value
5597whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
5598integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
5599type since they specify only a bit index.</p>
5600
5601<h5>Semantics:</h5>
5602<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
5603of operation: forwards and reverse. If <tt>%lo</tt> is greater than
5604<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
5605operates in forward mode.</p>
5606<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
5607truncating it down to the size of the replacement area or zero extending it
5608up to that size.</p>
5609<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5610are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5611in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
5612to the <tt>%hi</tt>th bit.
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5613<p>In reverse mode, a similar computation is made except that the bits are
5614reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
5615<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5616<h5>Examples:</h5>
5617<pre>
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5618 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5619 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5620 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5621 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5622 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]5623</pre>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5624</div>
5625
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5626<!-- ======================================================================= -->
5627<div class="doc_subsection">
5628 <a name="int_debugger">Debugger Intrinsics</a>
5629</div>
5630
5631<div class="doc_text">
5632<p>
5633The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
5634are described in the <a
5635href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
5636Debugging</a> document.
5637</p>
5638</div>
5639
5640
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]5641<!-- ======================================================================= -->
5642<div class="doc_subsection">
5643 <a name="int_eh">Exception Handling Intrinsics</a>
5644</div>
5645
5646<div class="doc_text">
5647<p> The LLVM exception handling intrinsics (which all start with
5648<tt>llvm.eh.</tt> prefix), are described in the <a
5649href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
5650Handling</a> document. </p>
5651</div>
5652
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5653<!-- ======================================================================= -->
5654<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5655 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5656</div>
5657
5658<div class="doc_text">
5659<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5660 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5661 the <tt>nest</tt> attribute, from a function. The result is a callable
5662 function pointer lacking the nest parameter - the caller does not need
5663 to provide a value for it. Instead, the value to use is stored in
5664 advance in a "trampoline", a block of memory usually allocated
5665 on the stack, which also contains code to splice the nest value into the
5666 argument list. This is used to implement the GCC nested function address
5667 extension.
5668</p>
5669<p>
5670 For example, if the function is
5671 <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]5672 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]5673<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5674 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
5675 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
5676 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
5677 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5678</pre>
Bill Wendling03295ca2007-09-22 09:23:55 +0000[diff] [blame]5679 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
5680 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5681</div>
5682
5683<!-- _______________________________________________________________________ -->
5684<div class="doc_subsubsection">
5685 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
5686</div>
5687<div class="doc_text">
5688<h5>Syntax:</h5>
5689<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5690declare 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]5691</pre>
5692<h5>Overview:</h5>
5693<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5694 This fills the memory pointed to by <tt>tramp</tt> with code
5695 and returns a function pointer suitable for executing it.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5696</p>
5697<h5>Arguments:</h5>
5698<p>
5699 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
5700 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
5701 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsc00c2ba2007-08-22 23:39:54 +0000[diff] [blame]5702 intrinsic. Note that the size and the alignment are target-specific - LLVM
5703 currently provides no portable way of determining them, so a front-end that
5704 generates this intrinsic needs to have some target-specific knowledge.
5705 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]5706</p>
5707<h5>Semantics:</h5>
5708<p>
5709 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5710 dependent code, turning it into a function. A pointer to this function is
5711 returned, but needs to be bitcast to an
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5712 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5713 before being called. The new function's signature is the same as that of
5714 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
5715 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
5716 of pointer type. Calling the new function is equivalent to calling
5717 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
5718 missing <tt>nest</tt> argument. If, after calling
5719 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
5720 modified, then the effect of any later call to the returned function pointer is
5721 undefined.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5722</p>
5723</div>
5724
5725<!-- ======================================================================= -->
5726<div class="doc_subsection">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]5727 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
5728</div>
5729
5730<div class="doc_text">
5731<p>
5732 These intrinsic functions expand the "universal IR" of LLVM to represent
5733 hardware constructs for atomic operations and memory synchronization. This
5734 provides an interface to the hardware, not an interface to the programmer. It
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5735 is aimed at a low enough level to allow any programming models or APIs
5736 (Application Programming Interfaces) which
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]5737 need atomic behaviors to map cleanly onto it. It is also modeled primarily on
5738 hardware behavior. Just as hardware provides a "universal IR" for source
5739 languages, it also provides a starting point for developing a "universal"
5740 atomic operation and synchronization IR.
5741</p>
5742<p>
5743 These do <em>not</em> form an API such as high-level threading libraries,
5744 software transaction memory systems, atomic primitives, and intrinsic
5745 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
5746 application libraries. The hardware interface provided by LLVM should allow
5747 a clean implementation of all of these APIs and parallel programming models.
5748 No one model or paradigm should be selected above others unless the hardware
5749 itself ubiquitously does so.
5750
5751</p>
5752</div>
5753
5754<!-- _______________________________________________________________________ -->
5755<div class="doc_subsubsection">
5756 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
5757</div>
5758<div class="doc_text">
5759<h5>Syntax:</h5>
5760<pre>
5761declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;,
5762i1 &lt;device&gt; )
5763
5764</pre>
5765<h5>Overview:</h5>
5766<p>
5767 The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
5768 specific pairs of memory access types.
5769</p>
5770<h5>Arguments:</h5>
5771<p>
5772 The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
5773 The first four arguments enables a specific barrier as listed below. The fith
5774 argument specifies that the barrier applies to io or device or uncached memory.
5775
5776</p>
5777 <ul>
5778 <li><tt>ll</tt>: load-load barrier</li>
5779 <li><tt>ls</tt>: load-store barrier</li>
5780 <li><tt>sl</tt>: store-load barrier</li>
5781 <li><tt>ss</tt>: store-store barrier</li>
5782 <li><tt>device</tt>: barrier applies to device and uncached memory also.
5783 </ul>
5784<h5>Semantics:</h5>
5785<p>
5786 This intrinsic causes the system to enforce some ordering constraints upon
5787 the loads and stores of the program. This barrier does not indicate
5788 <em>when</em> any events will occur, it only enforces an <em>order</em> in
5789 which they occur. For any of the specified pairs of load and store operations
5790 (f.ex. load-load, or store-load), all of the first operations preceding the
5791 barrier will complete before any of the second operations succeeding the
5792 barrier begin. Specifically the semantics for each pairing is as follows:
5793</p>
5794 <ul>
5795 <li><tt>ll</tt>: All loads before the barrier must complete before any load
5796 after the barrier begins.</li>
5797
5798 <li><tt>ls</tt>: All loads before the barrier must complete before any
5799 store after the barrier begins.</li>
5800 <li><tt>ss</tt>: All stores before the barrier must complete before any
5801 store after the barrier begins.</li>
5802 <li><tt>sl</tt>: All stores before the barrier must complete before any
5803 load after the barrier begins.</li>
5804 </ul>
5805<p>
5806 These semantics are applied with a logical "and" behavior when more than one
5807 is enabled in a single memory barrier intrinsic.
5808</p>
5809<p>
5810 Backends may implement stronger barriers than those requested when they do not
5811 support as fine grained a barrier as requested. Some architectures do not
5812 need all types of barriers and on such architectures, these become noops.
5813</p>
5814<h5>Example:</h5>
5815<pre>
5816%ptr = malloc i32
5817 store i32 4, %ptr
5818
5819%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
5820 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
5821 <i>; guarantee the above finishes</i>
5822 store i32 8, %ptr <i>; before this begins</i>
5823</pre>
5824</div>
5825
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5826<!-- _______________________________________________________________________ -->
5827<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]5828 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5829</div>
5830<div class="doc_text">
5831<h5>Syntax:</h5>
5832<p>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]5833 This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
5834 any integer bit width and for different address spaces. Not all targets
5835 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5836
5837<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]5838declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
5839declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
5840declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
5841declare 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]5842
5843</pre>
5844<h5>Overview:</h5>
5845<p>
5846 This loads a value in memory and compares it to a given value. If they are
5847 equal, it stores a new value into the memory.
5848</p>
5849<h5>Arguments:</h5>
5850<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]5851 The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5852 well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
5853 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
5854 this integer type. While any bit width integer may be used, targets may only
5855 lower representations they support in hardware.
5856
5857</p>
5858<h5>Semantics:</h5>
5859<p>
5860 This entire intrinsic must be executed atomically. It first loads the value
5861 in memory pointed to by <tt>ptr</tt> and compares it with the value
5862 <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
5863 loaded value is yielded in all cases. This provides the equivalent of an
5864 atomic compare-and-swap operation within the SSA framework.
5865</p>
5866<h5>Examples:</h5>
5867
5868<pre>
5869%ptr = malloc i32
5870 store i32 4, %ptr
5871
5872%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]5873%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5874 <i>; yields {i32}:result1 = 4</i>
5875%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
5876%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
5877
5878%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]5879%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5880 <i>; yields {i32}:result2 = 8</i>
5881%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
5882
5883%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
5884</pre>
5885</div>
5886
5887<!-- _______________________________________________________________________ -->
5888<div class="doc_subsubsection">
5889 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
5890</div>
5891<div class="doc_text">
5892<h5>Syntax:</h5>
5893
5894<p>
5895 This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
5896 integer bit width. Not all targets support all bit widths however.</p>
5897<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]5898declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
5899declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
5900declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
5901declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5902
5903</pre>
5904<h5>Overview:</h5>
5905<p>
5906 This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
5907 the value from memory. It then stores the value in <tt>val</tt> in the memory
5908 at <tt>ptr</tt>.
5909</p>
5910<h5>Arguments:</h5>
5911
5912<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]5913 The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5914 <tt>val</tt> argument and the result must be integers of the same bit width.
5915 The first argument, <tt>ptr</tt>, must be a pointer to a value of this
5916 integer type. The targets may only lower integer representations they
5917 support.
5918</p>
5919<h5>Semantics:</h5>
5920<p>
5921 This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
5922 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
5923 equivalent of an atomic swap operation within the SSA framework.
5924
5925</p>
5926<h5>Examples:</h5>
5927<pre>
5928%ptr = malloc i32
5929 store i32 4, %ptr
5930
5931%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]5932%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5933 <i>; yields {i32}:result1 = 4</i>
5934%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
5935%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
5936
5937%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]5938%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5939 <i>; yields {i32}:result2 = 8</i>
5940
5941%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
5942%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
5943</pre>
5944</div>
5945
5946<!-- _______________________________________________________________________ -->
5947<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]5948 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5949
5950</div>
5951<div class="doc_text">
5952<h5>Syntax:</h5>
5953<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]5954 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]5955 integer bit width. Not all targets support all bit widths however.</p>
5956<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]5957declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
5958declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
5959declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
5960declare 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]5961
5962</pre>
5963<h5>Overview:</h5>
5964<p>
5965 This intrinsic adds <tt>delta</tt> to the value stored in memory at
5966 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
5967</p>
5968<h5>Arguments:</h5>
5969<p>
5970
5971 The intrinsic takes two arguments, the first a pointer to an integer value
5972 and the second an integer value. The result is also an integer value. These
5973 integer types can have any bit width, but they must all have the same bit
5974 width. The targets may only lower integer representations they support.
5975</p>
5976<h5>Semantics:</h5>
5977<p>
5978 This intrinsic does a series of operations atomically. It first loads the
5979 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
5980 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
5981</p>
5982
5983<h5>Examples:</h5>
5984<pre>
5985%ptr = malloc i32
5986 store i32 4, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]5987%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5988 <i>; yields {i32}:result1 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]5989%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5990 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]5991%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5992 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]5993%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5994</pre>
5995</div>
5996
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]5997<!-- _______________________________________________________________________ -->
5998<div class="doc_subsubsection">
5999 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6000
6001</div>
6002<div class="doc_text">
6003<h5>Syntax:</h5>
6004<p>
6005 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]6006 any integer bit width and for different address spaces. Not all targets
6007 support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6008<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6009declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6010declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6011declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6012declare 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]6013
6014</pre>
6015<h5>Overview:</h5>
6016<p>
6017 This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6018 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6019</p>
6020<h5>Arguments:</h5>
6021<p>
6022
6023 The intrinsic takes two arguments, the first a pointer to an integer value
6024 and the second an integer value. The result is also an integer value. These
6025 integer types can have any bit width, but they must all have the same bit
6026 width. The targets may only lower integer representations they support.
6027</p>
6028<h5>Semantics:</h5>
6029<p>
6030 This intrinsic does a series of operations atomically. It first loads the
6031 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6032 result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6033</p>
6034
6035<h5>Examples:</h5>
6036<pre>
6037%ptr = malloc i32
6038 store i32 8, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6039%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6040 <i>; yields {i32}:result1 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6041%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6042 <i>; yields {i32}:result2 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6043%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6044 <i>; yields {i32}:result3 = 2</i>
6045%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6046</pre>
6047</div>
6048
6049<!-- _______________________________________________________________________ -->
6050<div class="doc_subsubsection">
6051 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6052 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6053 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6054 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
6055
6056</div>
6057<div class="doc_text">
6058<h5>Syntax:</h5>
6059<p>
6060 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
6061 <tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6062 <tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
6063 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6064<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6065declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6066declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6067declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6068declare 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]6069
6070</pre>
6071
6072<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6073declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6074declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6075declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6076declare 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]6077
6078</pre>
6079
6080<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6081declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6082declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6083declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6084declare 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]6085
6086</pre>
6087
6088<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6089declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6090declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6091declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6092declare 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]6093
6094</pre>
6095<h5>Overview:</h5>
6096<p>
6097 These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6098 the value stored in memory at <tt>ptr</tt>. It yields the original value
6099 at <tt>ptr</tt>.
6100</p>
6101<h5>Arguments:</h5>
6102<p>
6103
6104 These intrinsics take two arguments, the first a pointer to an integer value
6105 and the second an integer value. The result is also an integer value. These
6106 integer types can have any bit width, but they must all have the same bit
6107 width. The targets may only lower integer representations they support.
6108</p>
6109<h5>Semantics:</h5>
6110<p>
6111 These intrinsics does a series of operations atomically. They first load the
6112 value stored at <tt>ptr</tt>. They then do the bitwise operation
6113 <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
6114 value stored at <tt>ptr</tt>.
6115</p>
6116
6117<h5>Examples:</h5>
6118<pre>
6119%ptr = malloc i32
6120 store i32 0x0F0F, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6121%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6122 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6123%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6124 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6125%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6126 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6127%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6128 <i>; yields {i32}:result3 = FF</i>
6129%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6130</pre>
6131</div>
6132
6133
6134<!-- _______________________________________________________________________ -->
6135<div class="doc_subsubsection">
6136 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6137 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6138 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6139 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
6140
6141</div>
6142<div class="doc_text">
6143<h5>Syntax:</h5>
6144<p>
6145 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6146 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6147 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6148 address spaces. Not all targets
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6149 support all bit widths however.</p>
6150<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6151declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6152declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6153declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6154declare 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]6155
6156</pre>
6157
6158<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6159declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6160declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6161declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6162declare 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]6163
6164</pre>
6165
6166<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6167declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6168declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6169declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6170declare 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]6171
6172</pre>
6173
6174<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6175declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6176declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6177declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6178declare 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]6179
6180</pre>
6181<h5>Overview:</h5>
6182<p>
6183 These intrinsics takes the signed or unsigned minimum or maximum of
6184 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6185 original value at <tt>ptr</tt>.
6186</p>
6187<h5>Arguments:</h5>
6188<p>
6189
6190 These intrinsics take two arguments, the first a pointer to an integer value
6191 and the second an integer value. The result is also an integer value. These
6192 integer types can have any bit width, but they must all have the same bit
6193 width. The targets may only lower integer representations they support.
6194</p>
6195<h5>Semantics:</h5>
6196<p>
6197 These intrinsics does a series of operations atomically. They first load the
6198 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
6199 <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
6200 the original value stored at <tt>ptr</tt>.
6201</p>
6202
6203<h5>Examples:</h5>
6204<pre>
6205%ptr = malloc i32
6206 store i32 7, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6207%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6208 <i>; yields {i32}:result0 = 7</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6209%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6210 <i>; yields {i32}:result1 = -2</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6211%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6212 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6213%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6214 <i>; yields {i32}:result3 = 8</i>
6215%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6216</pre>
6217</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6218
6219<!-- ======================================================================= -->
6220<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6221 <a name="int_general">General Intrinsics</a>
6222</div>
6223
6224<div class="doc_text">
6225<p> This class of intrinsics is designed to be generic and has
6226no specific purpose. </p>
6227</div>
6228
6229<!-- _______________________________________________________________________ -->
6230<div class="doc_subsubsection">
6231 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6232</div>
6233
6234<div class="doc_text">
6235
6236<h5>Syntax:</h5>
6237<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]6238 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]6239</pre>
6240
6241<h5>Overview:</h5>
6242
6243<p>
6244The '<tt>llvm.var.annotation</tt>' intrinsic
6245</p>
6246
6247<h5>Arguments:</h5>
6248
6249<p>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]6250The first argument is a pointer to a value, the second is a pointer to a
6251global string, the third is a pointer to a global string which is the source
6252file name, and the last argument is the line number.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6253</p>
6254
6255<h5>Semantics:</h5>
6256
6257<p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6258This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6259This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6260annotations. These have no other defined use, they are ignored by code
6261generation and optimization.
6262</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6263</div>
6264
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6265<!-- _______________________________________________________________________ -->
6266<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]6267 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6268</div>
6269
6270<div class="doc_text">
6271
6272<h5>Syntax:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6273<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6274any integer bit width.
6275</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6276<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]6277 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6278 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6279 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6280 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6281 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]6282</pre>
6283
6284<h5>Overview:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6285
6286<p>
6287The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6288</p>
6289
6290<h5>Arguments:</h5>
6291
6292<p>
6293The first argument is an integer value (result of some expression),
6294the second is a pointer to a global string, the third is a pointer to a global
6295string which is the source file name, and the last argument is the line number.
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6296It returns the value of the first argument.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6297</p>
6298
6299<h5>Semantics:</h5>
6300
6301<p>
6302This intrinsic allows annotations to be put on arbitrary expressions
6303with arbitrary strings. This can be useful for special purpose optimizations
6304that want to look for these annotations. These have no other defined use, they
6305are ignored by code generation and optimization.
6306</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6307
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6308<!-- _______________________________________________________________________ -->
6309<div class="doc_subsubsection">
6310 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6311</div>
6312
6313<div class="doc_text">
6314
6315<h5>Syntax:</h5>
6316<pre>
6317 declare void @llvm.trap()
6318</pre>
6319
6320<h5>Overview:</h5>
6321
6322<p>
6323The '<tt>llvm.trap</tt>' intrinsic
6324</p>
6325
6326<h5>Arguments:</h5>
6327
6328<p>
6329None
6330</p>
6331
6332<h5>Semantics:</h5>
6333
6334<p>
6335This intrinsics is lowered to the target dependent trap instruction. If the
6336target does not have a trap instruction, this intrinsic will be lowered to the
6337call of the abort() function.
6338</p>
6339</div>
6340
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6341<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6342<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6343<address>
6344 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
6345 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
6346 <a href="http://validator.w3.org/check/referer"><img
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]6347 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6348
6349 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]6350 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6351 Last modified: $Date$
6352</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]6353
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6354</body>
6355</html>