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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 98245c7060a0a5399ca9e53f25541a5751ce4689 / . / 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 Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]25 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]26 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]27 <li><a href="#functionstructure">Functions</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]28 <li><a href="#aliasstructure">Aliases</a></li>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]29 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]30 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]31 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]32 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]33 <li><a href="#datalayout">Data Layout</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]34 </ol>
35 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]36 <li><a href="#typesystem">Type System</a>
37 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]38 <li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]39 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]40 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]41 <li><a href="#t_floating">Floating Point Types</a></li>
42 <li><a href="#t_void">Void Type</a></li>
43 <li><a href="#t_label">Label Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]44 </ol>
45 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]46 <li><a href="#t_derived">Derived Types</a>
47 <ol>
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]48 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]49 <li><a href="#t_array">Array Type</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]50 <li><a href="#t_function">Function Type</a></li>
51 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]52 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]53 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]54 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]55 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]56 </ol>
57 </li>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]58 <li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]59 </ol>
60 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]61 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]62 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]63 <li><a href="#simpleconstants">Simple Constants</a></li>
64 <li><a href="#aggregateconstants">Aggregate Constants</a></li>
65 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
66 <li><a href="#undefvalues">Undefined Values</a></li>
67 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]68 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]69 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]70 <li><a href="#othervalues">Other Values</a>
71 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]72 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]73 </ol>
74 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]75 <li><a href="#instref">Instruction Reference</a>
76 <ol>
77 <li><a href="#terminators">Terminator Instructions</a>
78 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]79 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
80 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]81 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
82 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]83 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]84 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]85 </ol>
86 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]87 <li><a href="#binaryops">Binary Operations</a>
88 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]89 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
90 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
91 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]92 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
93 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
94 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]95 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
96 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
97 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]98 </ol>
99 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]100 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
101 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]102 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
103 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
104 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]105 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]106 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]107 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]108 </ol>
109 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]110 <li><a href="#vectorops">Vector Operations</a>
111 <ol>
112 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
113 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
114 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]115 </ol>
116 </li>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]117 <li><a href="#aggregateops">Aggregate Operations</a>
118 <ol>
119 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
120 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
121 </ol>
122 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]123 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]124 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]125 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
126 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
127 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]128 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
129 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
130 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]131 </ol>
132 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]133 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]134 <ol>
135 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
136 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
137 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
138 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
139 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]140 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
141 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
142 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
143 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]144 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
145 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]146 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]147 </ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]148 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]149 <li><a href="#otherops">Other Operations</a>
150 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]151 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
152 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]153 <li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
154 <li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]155 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]156 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]157 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]158 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]159 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]160 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]161 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]162 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]163 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]164 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]165 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
166 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]167 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
168 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
169 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]170 </ol>
171 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]172 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
173 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]174 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
175 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
176 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]177 </ol>
178 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]179 <li><a href="#int_codegen">Code Generator Intrinsics</a>
180 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]181 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
182 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
183 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
184 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
185 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
186 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
187 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]188 </ol>
189 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]190 <li><a href="#int_libc">Standard C Library Intrinsics</a>
191 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]192 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
193 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
194 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
195 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
196 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]197 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
198 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
199 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]200 </ol>
201 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]202 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]203 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]204 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]205 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
206 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
207 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]208 <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
209 <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]210 </ol>
211 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]212 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]213 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]214 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]215 <ol>
216 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]217 </ol>
218 </li>
Bill Wendling3c44f5b2008-11-18 22:10:53 +0000[diff] [blame]219 <li><a href="#int_atomics">Atomic intrinsics</a>
220 <ol>
221 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
222 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
223 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
224 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
225 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
226 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
227 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
228 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
229 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
230 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
231 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
232 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
233 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
234 </ol>
235 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]236 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]237 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]238 <li><a href="#int_var_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]239 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]240 <li><a href="#int_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]241 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]242 <li><a href="#int_trap">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]243 '<tt>llvm.trap</tt>' Intrinsic</a></li>
244 <li><a href="#int_stackprotector">
245 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]246 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]247 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]248 </ol>
249 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]250</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]251
252<div class="doc_author">
253 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
254 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]255</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]256
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]257<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]258<div class="doc_section"> <a name="abstract">Abstract </a></div>
259<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]260
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]261<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]262<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling837f39b2008-08-05 22:29:16 +0000[diff] [blame]263LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]264type safety, low-level operations, flexibility, and the capability of
265representing 'all' high-level languages cleanly. It is the common code
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]266representation used throughout all phases of the LLVM compilation
267strategy.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]268</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]269
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]270<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]271<div class="doc_section"> <a name="introduction">Introduction</a> </div>
272<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]273
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]274<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]275
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]276<p>The LLVM code representation is designed to be used in three
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]277different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]278representation (suitable for fast loading by a Just-In-Time compiler),
279and as a human readable assembly language representation. This allows
280LLVM to provide a powerful intermediate representation for efficient
281compiler transformations and analysis, while providing a natural means
282to debug and visualize the transformations. The three different forms
283of LLVM are all equivalent. This document describes the human readable
284representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]285
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]286<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]287while being expressive, typed, and extensible at the same time. It
288aims to be a "universal IR" of sorts, by being at a low enough level
289that high-level ideas may be cleanly mapped to it (similar to how
290microprocessors are "universal IR's", allowing many source languages to
291be mapped to them). By providing type information, LLVM can be used as
292the target of optimizations: for example, through pointer analysis, it
293can be proven that a C automatic variable is never accessed outside of
294the current function... allowing it to be promoted to a simple SSA
295value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]296
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]297</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]298
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]299<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]300<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]301
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]302<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]303
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]304<p>It is important to note that this document describes 'well formed'
305LLVM assembly language. There is a difference between what the parser
306accepts and what is considered 'well formed'. For example, the
307following instruction is syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]308
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]309<div class="doc_code">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]310<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]311%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]312</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]313</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]314
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]315<p>...because the definition of <tt>%x</tt> does not dominate all of
316its uses. The LLVM infrastructure provides a verification pass that may
317be used to verify that an LLVM module is well formed. This pass is
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]318automatically run by the parser after parsing input assembly and by
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]319the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]320by the verifier pass indicate bugs in transformation passes or input to
321the parser.</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]322</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]323
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]324<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]325
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]326<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]327<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]328<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]329
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]330<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]331
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]332 <p>LLVM identifiers come in two basic types: global and local. Global
333 identifiers (functions, global variables) begin with the @ character. Local
334 identifiers (register names, types) begin with the % character. Additionally,
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]335 there are three different formats for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]336
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]337<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]338 <li>Named values are represented as a string of characters with their prefix.
339 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
340 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]341 Identifiers which require other characters in their names can be surrounded
Daniel Dunbar76dea952008-10-14 23:51:43 +0000[diff] [blame]342 with quotes. Special characters may be escaped using "\xx" where xx is the
343 ASCII code for the character in hexadecimal. In this way, any character can
344 be used in a name value, even quotes themselves.
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]345
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]346 <li>Unnamed values are represented as an unsigned numeric value with their
347 prefix. For example, %12, @2, %44.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]348
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]349 <li>Constants, which are described in a <a href="#constants">section about
350 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]351</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]352
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]353<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]354don't need to worry about name clashes with reserved words, and the set of
355reserved words may be expanded in the future without penalty. Additionally,
356unnamed identifiers allow a compiler to quickly come up with a temporary
357variable without having to avoid symbol table conflicts.</p>
358
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]359<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]360languages. There are keywords for different opcodes
361('<tt><a href="#i_add">add</a></tt>',
362 '<tt><a href="#i_bitcast">bitcast</a></tt>',
363 '<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]364href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]365and others. These reserved words cannot conflict with variable names, because
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]366none of them start with a prefix character ('%' or '@').</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]367
368<p>Here is an example of LLVM code to multiply the integer variable
369'<tt>%X</tt>' by 8:</p>
370
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]371<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]372
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]373<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]374<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]375%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]376</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]377</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]378
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]379<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]380
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]381<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]382<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]383%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]384</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]385</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]386
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]387<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]388
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]389<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]390<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]391<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
392<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
393%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]394</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]395</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]396
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]397<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
398important lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]399
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]400<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]401
402 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
403 line.</li>
404
405 <li>Unnamed temporaries are created when the result of a computation is not
406 assigned to a named value.</li>
407
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]408 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]409
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]410</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]411
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]412<p>...and it also shows a convention that we follow in this document. When
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]413demonstrating instructions, we will follow an instruction with a comment that
414defines the type and name of value produced. Comments are shown in italic
415text.</p>
416
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]417</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]418
419<!-- *********************************************************************** -->
420<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
421<!-- *********************************************************************** -->
422
423<!-- ======================================================================= -->
424<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
425</div>
426
427<div class="doc_text">
428
429<p>LLVM programs are composed of "Module"s, each of which is a
430translation unit of the input programs. Each module consists of
431functions, global variables, and symbol table entries. Modules may be
432combined together with the LLVM linker, which merges function (and
433global variable) definitions, resolves forward declarations, and merges
434symbol table entries. Here is an example of the "hello world" module:</p>
435
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]436<div class="doc_code">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]437<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]438<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
439 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]440
441<i>; External declaration of the puts function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]442<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]443
444<i>; Definition of main function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]445define i32 @main() { <i>; i32()* </i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]446 <i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]447 %cast210 = <a
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]448 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]449
450 <i>; Call puts function to write out the string to stdout...</i>
451 <a
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]452 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]453 <a
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]454 href="#i_ret">ret</a> i32 0<br>}<br>
455</pre>
456</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]457
458<p>This example is made up of a <a href="#globalvars">global variable</a>
459named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
460function, and a <a href="#functionstructure">function definition</a>
461for "<tt>main</tt>".</p>
462
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]463<p>In general, a module is made up of a list of global values,
464where both functions and global variables are global values. Global values are
465represented by a pointer to a memory location (in this case, a pointer to an
466array of char, and a pointer to a function), and have one of the following <a
467href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]468
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]469</div>
470
471<!-- ======================================================================= -->
472<div class="doc_subsection">
473 <a name="linkage">Linkage Types</a>
474</div>
475
476<div class="doc_text">
477
478<p>
479All Global Variables and Functions have one of the following types of linkage:
480</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]481
482<dl>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]483
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]484 <dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
485
486 <dd>Global values with private linkage are only directly accessible by
487 objects in the current module. In particular, linking code into a module with
488 an private global value may cause the private to be renamed as necessary to
489 avoid collisions. Because the symbol is private to the module, all
490 references can be updated. This doesn't show up in any symbol table in the
491 object file.
492 </dd>
493
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]494 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]495
Duncan Sands81d05c22009-01-16 09:29:46 +0000[diff] [blame]496 <dd> Similar to private, but the value shows as a local symbol (STB_LOCAL in
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]497 the case of ELF) in the object file. This corresponds to the notion of the
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]498 '<tt>static</tt>' keyword in C.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]499 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]500
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]501 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]502
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]503 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
504 the same name when linkage occurs. This is typically used to implement
505 inline functions, templates, or other code which must be generated in each
506 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
507 allowed to be discarded.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]508 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]509
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]510 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
511
512 <dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
513 linkage, except that unreferenced <tt>common</tt> globals may not be
514 discarded. This is used for globals that may be emitted in multiple
515 translation units, but that are not guaranteed to be emitted into every
516 translation unit that uses them. One example of this is tentative
517 definitions in C, such as "<tt>int X;</tt>" at global scope.
518 </dd>
519
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]520 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]521
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]522 <dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
523 that some targets may choose to emit different assembly sequences for them
524 for target-dependent reasons. This is used for globals that are declared
525 "weak" in C source code.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]526 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]527
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]528 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]529
530 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
531 pointer to array type. When two global variables with appending linkage are
532 linked together, the two global arrays are appended together. This is the
533 LLVM, typesafe, equivalent of having the system linker append together
534 "sections" with identical names when .o files are linked.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]535 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]536
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]537 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]538 <dd>The semantics of this linkage follow the ELF object file model: the
539 symbol is weak until linked, if not linked, the symbol becomes null instead
540 of being an undefined reference.
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]541 </dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]542
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]543 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]544
545 <dd>If none of the above identifiers are used, the global is externally
546 visible, meaning that it participates in linkage and can be used to resolve
547 external symbol references.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]548 </dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]549</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]550
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]551 <p>
552 The next two types of linkage are targeted for Microsoft Windows platform
553 only. They are designed to support importing (exporting) symbols from (to)
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]554 DLLs (Dynamic Link Libraries).
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]555 </p>
556
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]557 <dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]558 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
559
560 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
561 or variable via a global pointer to a pointer that is set up by the DLL
562 exporting the symbol. On Microsoft Windows targets, the pointer name is
Dan Gohman79564122009-01-12 21:35:55 +0000[diff] [blame]563 formed by combining <code>__imp_</code> and the function or variable name.
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]564 </dd>
565
566 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
567
568 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
569 pointer to a pointer in a DLL, so that it can be referenced with the
570 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
Dan Gohman79564122009-01-12 21:35:55 +0000[diff] [blame]571 name is formed by combining <code>__imp_</code> and the function or variable
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]572 name.
573 </dd>
574
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]575</dl>
576
Dan Gohmanf0032762008-11-24 17:18:39 +0000[diff] [blame]577<p>For example, since the "<tt>.LC0</tt>"
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]578variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
579variable and was linked with this one, one of the two would be renamed,
580preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
581external (i.e., lacking any linkage declarations), they are accessible
Reid Spencerac8d2762007-01-05 00:59:10 +0000[diff] [blame]582outside of the current module.</p>
583<p>It is illegal for a function <i>declaration</i>
584to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]585or <tt>extern_weak</tt>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]586<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]587linkages.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]588</div>
589
590<!-- ======================================================================= -->
591<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]592 <a name="callingconv">Calling Conventions</a>
593</div>
594
595<div class="doc_text">
596
597<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
598and <a href="#i_invoke">invokes</a> can all have an optional calling convention
599specified for the call. The calling convention of any pair of dynamic
600caller/callee must match, or the behavior of the program is undefined. The
601following calling conventions are supported by LLVM, and more may be added in
602the future:</p>
603
604<dl>
605 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
606
607 <dd>This calling convention (the default if no other calling convention is
608 specified) matches the target C calling conventions. This calling convention
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]609 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencerc28d2bc2006-12-31 21:30:18 +0000[diff] [blame]610 prototype and implemented declaration of the function (as does normal C).
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]611 </dd>
612
613 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
614
615 <dd>This calling convention attempts to make calls as fast as possible
616 (e.g. by passing things in registers). This calling convention allows the
617 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]618 without having to conform to an externally specified ABI (Application Binary
619 Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer9097d142008-05-14 09:17:12 +0000[diff] [blame]620 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
621 supported. This calling convention does not support varargs and requires the
622 prototype of all callees to exactly match the prototype of the function
623 definition.
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]624 </dd>
625
626 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
627
628 <dd>This calling convention attempts to make code in the caller as efficient
629 as possible under the assumption that the call is not commonly executed. As
630 such, these calls often preserve all registers so that the call does not break
631 any live ranges in the caller side. This calling convention does not support
632 varargs and requires the prototype of all callees to exactly match the
633 prototype of the function definition.
634 </dd>
635
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]636 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]637
638 <dd>Any calling convention may be specified by number, allowing
639 target-specific calling conventions to be used. Target specific calling
640 conventions start at 64.
641 </dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]642</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]643
644<p>More calling conventions can be added/defined on an as-needed basis, to
645support pascal conventions or any other well-known target-independent
646convention.</p>
647
648</div>
649
650<!-- ======================================================================= -->
651<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]652 <a name="visibility">Visibility Styles</a>
653</div>
654
655<div class="doc_text">
656
657<p>
658All Global Variables and Functions have one of the following visibility styles:
659</p>
660
661<dl>
662 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
663
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]664 <dd>On targets that use the ELF object file format, default visibility means
665 that the declaration is visible to other
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]666 modules and, in shared libraries, means that the declared entity may be
667 overridden. On Darwin, default visibility means that the declaration is
668 visible to other modules. Default visibility corresponds to "external
669 linkage" in the language.
670 </dd>
671
672 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
673
674 <dd>Two declarations of an object with hidden visibility refer to the same
675 object if they are in the same shared object. Usually, hidden visibility
676 indicates that the symbol will not be placed into the dynamic symbol table,
677 so no other module (executable or shared library) can reference it
678 directly.
679 </dd>
680
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]681 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
682
683 <dd>On ELF, protected visibility indicates that the symbol will be placed in
684 the dynamic symbol table, but that references within the defining module will
685 bind to the local symbol. That is, the symbol cannot be overridden by another
686 module.
687 </dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]688</dl>
689
690</div>
691
692<!-- ======================================================================= -->
693<div class="doc_subsection">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]694 <a name="namedtypes">Named Types</a>
695</div>
696
697<div class="doc_text">
698
699<p>LLVM IR allows you to specify name aliases for certain types. This can make
700it easier to read the IR and make the IR more condensed (particularly when
701recursive types are involved). An example of a name specification is:
702</p>
703
704<div class="doc_code">
705<pre>
706%mytype = type { %mytype*, i32 }
707</pre>
708</div>
709
710<p>You may give a name to any <a href="#typesystem">type</a> except "<a
711href="t_void">void</a>". Type name aliases may be used anywhere a type is
712expected with the syntax "%mytype".</p>
713
714<p>Note that type names are aliases for the structural type that they indicate,
715and that you can therefore specify multiple names for the same type. This often
716leads to confusing behavior when dumping out a .ll file. Since LLVM IR uses
717structural typing, the name is not part of the type. When printing out LLVM IR,
718the printer will pick <em>one name</em> to render all types of a particular
719shape. This means that if you have code where two different source types end up
720having the same LLVM type, that the dumper will sometimes print the "wrong" or
721unexpected type. This is an important design point and isn't going to
722change.</p>
723
724</div>
725
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]726<!-- ======================================================================= -->
727<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]728 <a name="globalvars">Global Variables</a>
729</div>
730
731<div class="doc_text">
732
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]733<p>Global variables define regions of memory allocated at compilation time
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]734instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]735an explicit section to be placed in, and may have an optional explicit alignment
736specified. A variable may be defined as "thread_local", which means that it
737will not be shared by threads (each thread will have a separated copy of the
738variable). A variable may be defined as a global "constant," which indicates
739that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]740optimization, allowing the global data to be placed in the read-only section of
741an executable, etc). Note that variables that need runtime initialization
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]742cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]743
744<p>
745LLVM explicitly allows <em>declarations</em> of global variables to be marked
746constant, even if the final definition of the global is not. This capability
747can be used to enable slightly better optimization of the program, but requires
748the language definition to guarantee that optimizations based on the
749'constantness' are valid for the translation units that do not include the
750definition.
751</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]752
753<p>As SSA values, global variables define pointer values that are in
754scope (i.e. they dominate) all basic blocks in the program. Global
755variables always define a pointer to their "content" type because they
756describe a region of memory, and all memory objects in LLVM are
757accessed through pointers.</p>
758
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]759<p>A global variable may be declared to reside in a target-specifc numbered
760address space. For targets that support them, address spaces may affect how
761optimizations are performed and/or what target instructions are used to access
Christopher Lambd49e18d2007-12-12 08:44:39 +0000[diff] [blame]762the variable. The default address space is zero. The address space qualifier
763must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]764
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]765<p>LLVM allows an explicit section to be specified for globals. If the target
766supports it, it will emit globals to the section specified.</p>
767
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]768<p>An explicit alignment may be specified for a global. If not present, or if
769the alignment is set to zero, the alignment of the global is set by the target
770to whatever it feels convenient. If an explicit alignment is specified, the
771global is forced to have at least that much alignment. All alignments must be
772a power of 2.</p>
773
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]774<p>For example, the following defines a global in a numbered address space with
775an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]776
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]777<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]778<pre>
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]779@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]780</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]781</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]782
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]783</div>
784
785
786<!-- ======================================================================= -->
787<div class="doc_subsection">
788 <a name="functionstructure">Functions</a>
789</div>
790
791<div class="doc_text">
792
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]793<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
794an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]795<a href="#visibility">visibility style</a>, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]796<a href="#callingconv">calling convention</a>, a return type, an optional
797<a href="#paramattrs">parameter attribute</a> for the return type, a function
798name, a (possibly empty) argument list (each with optional
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]799<a href="#paramattrs">parameter attributes</a>), optional
800<a href="#fnattrs">function attributes</a>, an optional section,
801an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner0c46a7d2008-10-04 18:10:21 +0000[diff] [blame]802an opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]803
804LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
805optional <a href="#linkage">linkage type</a>, an optional
806<a href="#visibility">visibility style</a>, an optional
807<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]808<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]809name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksene754abe2007-12-10 03:30:21 +0000[diff] [blame]810<a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]811
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]812<p>A function definition contains a list of basic blocks, forming the CFG
813(Control Flow Graph) for
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]814the function. Each basic block may optionally start with a label (giving the
815basic block a symbol table entry), contains a list of instructions, and ends
816with a <a href="#terminators">terminator</a> instruction (such as a branch or
817function return).</p>
818
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]819<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]820executed on entrance to the function, and it is not allowed to have predecessor
821basic blocks (i.e. there can not be any branches to the entry block of a
822function). Because the block can have no predecessors, it also cannot have any
823<a href="#i_phi">PHI nodes</a>.</p>
824
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]825<p>LLVM allows an explicit section to be specified for functions. If the target
826supports it, it will emit functions to the section specified.</p>
827
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]828<p>An explicit alignment may be specified for a function. If not present, or if
829the alignment is set to zero, the alignment of the function is set by the target
830to whatever it feels convenient. If an explicit alignment is specified, the
831function is forced to have at least that much alignment. All alignments must be
832a power of 2.</p>
833
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]834 <h5>Syntax:</h5>
835
836<div class="doc_code">
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]837<tt>
838define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
839 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
840 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
841 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
842 [<a href="#gc">gc</a>] { ... }
843</tt>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]844</div>
845
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]846</div>
847
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]848
849<!-- ======================================================================= -->
850<div class="doc_subsection">
851 <a name="aliasstructure">Aliases</a>
852</div>
853<div class="doc_text">
854 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov726d45c2008-03-22 08:36:14 +0000[diff] [blame]855 function, global variable, another alias or bitcast of global value). Aliases
856 may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]857 optional <a href="#visibility">visibility style</a>.</p>
858
859 <h5>Syntax:</h5>
860
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]861<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]862<pre>
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]863@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]864</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]865</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]866
867</div>
868
869
870
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]871<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]872<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
873<div class="doc_text">
874 <p>The return type and each parameter of a function type may have a set of
875 <i>parameter attributes</i> associated with them. Parameter attributes are
876 used to communicate additional information about the result or parameters of
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]877 a function. Parameter attributes are considered to be part of the function,
878 not of the function type, so functions with different parameter attributes
879 can have the same function type.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]880
Reid Spencer950e9f82007-01-15 18:27:39 +0000[diff] [blame]881 <p>Parameter attributes are simple keywords that follow the type specified. If
882 multiple parameter attributes are needed, they are space separated. For
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]883 example:</p>
884
885<div class="doc_code">
886<pre>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]887declare i32 @printf(i8* noalias , ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]888declare i32 @atoi(i8 zeroext)
889declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]890</pre>
891</div>
892
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]893 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
894 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]895
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]896 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]897 <dl>
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]898 <dt><tt>zeroext</tt></dt>
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]899 <dd>This indicates to the code generator that the parameter or return value
900 should be zero-extended to a 32-bit value by the caller (for a parameter)
901 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]902
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]903 <dt><tt>signext</tt></dt>
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]904 <dd>This indicates to the code generator that the parameter or return value
905 should be sign-extended to a 32-bit value by the caller (for a parameter)
906 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]907
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]908 <dt><tt>inreg</tt></dt>
Dale Johannesenc9c6da62008-09-25 20:47:45 +0000[diff] [blame]909 <dd>This indicates that this parameter or return value should be treated
910 in a special target-dependent fashion during while emitting code for a
911 function call or return (usually, by putting it in a register as opposed
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]912 to memory, though some targets use it to distinguish between two different
913 kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]914
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]915 <dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner0747baa2008-01-15 04:34:22 +0000[diff] [blame]916 <dd>This indicates that the pointer parameter should really be passed by
917 value to the function. The attribute implies that a hidden copy of the
918 pointee is made between the caller and the callee, so the callee is unable
Chris Lattnerebec6782008-08-05 18:21:08 +0000[diff] [blame]919 to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner0747baa2008-01-15 04:34:22 +0000[diff] [blame]920 pointer arguments. It is generally used to pass structs and arrays by
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]921 value, but is also valid on pointers to scalars. The copy is considered to
922 belong to the caller not the callee (for example,
923 <tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]924 <tt>byval</tt> parameters). This is not a valid attribute for return
925 values. </dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]926
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]927 <dt><tt>sret</tt></dt>
Duncan Sandse26dec62008-02-18 04:19:38 +0000[diff] [blame]928 <dd>This indicates that the pointer parameter specifies the address of a
929 structure that is the return value of the function in the source program.
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]930 This pointer must be guaranteed by the caller to be valid: loads and stores
931 to the structure may be assumed by the callee to not to trap. This may only
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]932 be applied to the first parameter. This is not a valid attribute for
933 return values. </dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]934
Zhou Shengfebca342007-06-05 05:28:26 +0000[diff] [blame]935 <dt><tt>noalias</tt></dt>
Nick Lewycky02ff3082008-11-24 03:41:24 +0000[diff] [blame]936 <dd>This indicates that the pointer does not alias any global or any other
937 parameter. The caller is responsible for ensuring that this is the
Nick Lewyckyb2b32fd2008-11-24 05:00:44 +0000[diff] [blame]938 case. On a function return value, <tt>noalias</tt> additionally indicates
939 that the pointer does not alias any other pointers visible to the
Nick Lewyckyf23d0d32008-12-19 06:39:12 +0000[diff] [blame]940 caller. For further details, please see the discussion of the NoAlias
941 response in
942 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
943 analysis</a>.</dd>
944
945 <dt><tt>nocapture</tt></dt>
946 <dd>This indicates that the callee does not make any copies of the pointer
947 that outlive the callee itself. This is not a valid attribute for return
948 values.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]949
Duncan Sands50f19f52007-07-27 19:57:41 +0000[diff] [blame]950 <dt><tt>nest</tt></dt>
Duncan Sands0789b8b2008-07-08 09:27:25 +0000[diff] [blame]951 <dd>This indicates that the pointer parameter can be excised using the
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]952 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
953 attribute for return values.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]954 </dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]955
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]956</div>
957
958<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]959<div class="doc_subsection">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]960 <a name="gc">Garbage Collector Names</a>
961</div>
962
963<div class="doc_text">
964<p>Each function may specify a garbage collector name, which is simply a
965string.</p>
966
967<div class="doc_code"><pre
968>define void @f() gc "name" { ...</pre></div>
969
970<p>The compiler declares the supported values of <i>name</i>. Specifying a
971collector which will cause the compiler to alter its output in order to support
972the named garbage collection algorithm.</p>
973</div>
974
975<!-- ======================================================================= -->
976<div class="doc_subsection">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]977 <a name="fnattrs">Function Attributes</a>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]978</div>
979
980<div class="doc_text">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]981
982<p>Function attributes are set to communicate additional information about
983 a function. Function attributes are considered to be part of the function,
984 not of the function type, so functions with different parameter attributes
985 can have the same function type.</p>
986
987 <p>Function attributes are simple keywords that follow the type specified. If
988 multiple attributes are needed, they are space separated. For
989 example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]990
991<div class="doc_code">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]992<pre>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]993define void @f() noinline { ... }
994define void @f() alwaysinline { ... }
995define void @f() alwaysinline optsize { ... }
996define void @f() optsize
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]997</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]998</div>
999
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1000<dl>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1001<dt><tt>alwaysinline</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1002<dd>This attribute indicates that the inliner should attempt to inline this
1003function into callers whenever possible, ignoring any active inlining size
1004threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1005
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1006<dt><tt>noinline</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1007<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner94b5f7d2008-10-05 17:14:59 +0000[diff] [blame]1008in any situation. This attribute may not be used together with the
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1009<tt>alwaysinline</tt> attribute.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1010
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1011<dt><tt>optsize</tt></dt>
Devang Patel66c6c652008-09-29 18:34:44 +0000[diff] [blame]1012<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1013make choices that keep the code size of this function low, and otherwise do
1014optimizations specifically to reduce code size.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1015
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1016<dt><tt>noreturn</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1017<dd>This function attribute indicates that the function never returns normally.
1018This produces undefined behavior at runtime if the function ever does
1019dynamically return.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1020
1021<dt><tt>nounwind</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1022<dd>This function attribute indicates that the function never returns with an
1023unwind or exceptional control flow. If the function does unwind, its runtime
1024behavior is undefined.</dd>
1025
1026<dt><tt>readnone</tt></dt>
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]1027<dd>This attribute indicates that the function computes its result (or the
1028exception it throws) based strictly on its arguments, without dereferencing any
1029pointer arguments or otherwise accessing any mutable state (e.g. memory, control
1030registers, etc) visible to caller functions. It does not write through any
1031pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
1032never changes any state visible to callers.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1033
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]1034<dt><tt><a name="readonly">readonly</a></tt></dt>
1035<dd>This attribute indicates that the function does not write through any
1036pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
1037or otherwise modify any state (e.g. memory, control registers, etc) visible to
1038caller functions. It may dereference pointer arguments and read state that may
1039be set in the caller. A readonly function always returns the same value (or
1040throws the same exception) when called with the same set of arguments and global
1041state.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1042
1043<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1044<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1045protector. It is in the form of a "canary"&mdash;a random value placed on the
1046stack before the local variables that's checked upon return from the function to
1047see if it has been overwritten. A heuristic is used to determine if a function
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1048needs stack protectors or not.
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1049
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1050<p>If a function that has an <tt>ssp</tt> attribute is inlined into a function
1051that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
1052have an <tt>ssp</tt> attribute.</p></dd>
1053
1054<dt><tt>sspreq</tt></dt>
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1055<dd>This attribute indicates that the function should <em>always</em> emit a
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1056stack smashing protector. This overrides the <tt><a href="#ssp">ssp</a></tt>
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1057function attribute.
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1058
1059<p>If a function that has an <tt>sspreq</tt> attribute is inlined into a
1060function that doesn't have an <tt>sspreq</tt> attribute or which has
1061an <tt>ssp</tt> attribute, then the resulting function will have
1062an <tt>sspreq</tt> attribute.</p></dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1063</dl>
1064
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1065</div>
1066
1067<!-- ======================================================================= -->
1068<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1069 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1070</div>
1071
1072<div class="doc_text">
1073<p>
1074Modules may contain "module-level inline asm" blocks, which corresponds to the
1075GCC "file scope inline asm" blocks. These blocks are internally concatenated by
1076LLVM and treated as a single unit, but may be separated in the .ll file if
1077desired. The syntax is very simple:
1078</p>
1079
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1080<div class="doc_code">
1081<pre>
1082module asm "inline asm code goes here"
1083module asm "more can go here"
1084</pre>
1085</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1086
1087<p>The strings can contain any character by escaping non-printable characters.
1088 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
1089 for the number.
1090</p>
1091
1092<p>
1093 The inline asm code is simply printed to the machine code .s file when
1094 assembly code is generated.
1095</p>
1096</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1097
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1098<!-- ======================================================================= -->
1099<div class="doc_subsection">
1100 <a name="datalayout">Data Layout</a>
1101</div>
1102
1103<div class="doc_text">
1104<p>A module may specify a target specific data layout string that specifies how
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]1105data is to be laid out in memory. The syntax for the data layout is simply:</p>
1106<pre> target datalayout = "<i>layout specification</i>"</pre>
1107<p>The <i>layout specification</i> consists of a list of specifications
1108separated by the minus sign character ('-'). Each specification starts with a
1109letter and may include other information after the letter to define some
1110aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1111<dl>
1112 <dt><tt>E</tt></dt>
1113 <dd>Specifies that the target lays out data in big-endian form. That is, the
1114 bits with the most significance have the lowest address location.</dd>
1115 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1116 <dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1117 the bits with the least significance have the lowest address location.</dd>
1118 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1119 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
1120 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
1121 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
1122 too.</dd>
1123 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1124 <dd>This specifies the alignment for an integer type of a given bit
1125 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1126 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1127 <dd>This specifies the alignment for a vector type of a given bit
1128 <i>size</i>.</dd>
1129 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1130 <dd>This specifies the alignment for a floating point type of a given bit
1131 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1132 (double).</dd>
1133 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1134 <dd>This specifies the alignment for an aggregate type of a given bit
1135 <i>size</i>.</dd>
1136</dl>
1137<p>When constructing the data layout for a given target, LLVM starts with a
1138default set of specifications which are then (possibly) overriden by the
1139specifications in the <tt>datalayout</tt> keyword. The default specifications
1140are given in this list:</p>
1141<ul>
1142 <li><tt>E</tt> - big endian</li>
1143 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1144 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1145 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1146 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1147 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1148 <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]1149 alignment of 64-bits</li>
1150 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1151 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1152 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1153 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1154 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
1155</ul>
Chris Lattnerebec6782008-08-05 18:21:08 +0000[diff] [blame]1156<p>When LLVM is determining the alignment for a given type, it uses the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1157following rules:</p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1158<ol>
1159 <li>If the type sought is an exact match for one of the specifications, that
1160 specification is used.</li>
1161 <li>If no match is found, and the type sought is an integer type, then the
1162 smallest integer type that is larger than the bitwidth of the sought type is
1163 used. If none of the specifications are larger than the bitwidth then the the
1164 largest integer type is used. For example, given the default specifications
1165 above, the i7 type will use the alignment of i8 (next largest) while both
1166 i65 and i256 will use the alignment of i64 (largest specified).</li>
1167 <li>If no match is found, and the type sought is a vector type, then the
1168 largest vector type that is smaller than the sought vector type will be used
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1169 as a fall back. This happens because &lt;128 x double&gt; can be implemented
1170 in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1171</ol>
1172</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1173
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1174<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1175<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1176<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1177
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1178<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1179
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1180<p>The LLVM type system is one of the most important features of the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1181intermediate representation. Being typed enables a number of
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1182optimizations to be performed on the intermediate representation directly,
1183without having to do
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1184extra analyses on the side before the transformation. A strong type
1185system makes it easier to read the generated code and enables novel
1186analyses and transformations that are not feasible to perform on normal
1187three address code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1188
1189</div>
1190
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1191<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1192<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1193Classifications</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1194<div class="doc_text">
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1195<p>The types fall into a few useful
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1196classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1197
1198<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1199 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1200 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1201 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1202 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1203 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1204 </tr>
1205 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1206 <td><a href="#t_floating">floating point</a></td>
1207 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1208 </tr>
1209 <tr>
1210 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1211 <td><a href="#t_integer">integer</a>,
1212 <a href="#t_floating">floating point</a>,
1213 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1214 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1215 <a href="#t_struct">structure</a>,
1216 <a href="#t_array">array</a>,
Dan Gohmanade5faa2008-05-23 22:50:26 +0000[diff] [blame]1217 <a href="#t_label">label</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1218 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1219 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1220 <tr>
1221 <td><a href="#t_primitive">primitive</a></td>
1222 <td><a href="#t_label">label</a>,
1223 <a href="#t_void">void</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1224 <a href="#t_floating">floating point</a>.</td>
1225 </tr>
1226 <tr>
1227 <td><a href="#t_derived">derived</a></td>
1228 <td><a href="#t_integer">integer</a>,
1229 <a href="#t_array">array</a>,
1230 <a href="#t_function">function</a>,
1231 <a href="#t_pointer">pointer</a>,
1232 <a href="#t_struct">structure</a>,
1233 <a href="#t_pstruct">packed structure</a>,
1234 <a href="#t_vector">vector</a>,
1235 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1236 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1237 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1238 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1239</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1240
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1241<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1242most important. Values of these types are the only ones which can be
1243produced by instructions, passed as arguments, or used as operands to
Dan Gohmanc4b49eb2008-05-23 21:53:15 +0000[diff] [blame]1244instructions.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1245</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1246
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1247<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1248<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1249
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1250<div class="doc_text">
1251<p>The primitive types are the fundamental building blocks of the LLVM
1252system.</p>
1253
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1254</div>
1255
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1256<!-- _______________________________________________________________________ -->
1257<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1258
1259<div class="doc_text">
1260 <table>
1261 <tbody>
1262 <tr><th>Type</th><th>Description</th></tr>
1263 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1264 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1265 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1266 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1267 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1268 </tbody>
1269 </table>
1270</div>
1271
1272<!-- _______________________________________________________________________ -->
1273<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1274
1275<div class="doc_text">
1276<h5>Overview:</h5>
1277<p>The void type does not represent any value and has no size.</p>
1278
1279<h5>Syntax:</h5>
1280
1281<pre>
1282 void
1283</pre>
1284</div>
1285
1286<!-- _______________________________________________________________________ -->
1287<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1288
1289<div class="doc_text">
1290<h5>Overview:</h5>
1291<p>The label type represents code labels.</p>
1292
1293<h5>Syntax:</h5>
1294
1295<pre>
1296 label
1297</pre>
1298</div>
1299
1300
1301<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1302<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1303
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1304<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1305
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1306<p>The real power in LLVM comes from the derived types in the system.
1307This is what allows a programmer to represent arrays, functions,
1308pointers, and other useful types. Note that these derived types may be
1309recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1310
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1311</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1312
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1313<!-- _______________________________________________________________________ -->
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1314<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1315
1316<div class="doc_text">
1317
1318<h5>Overview:</h5>
1319<p>The integer type is a very simple derived type that simply specifies an
1320arbitrary bit width for the integer type desired. Any bit width from 1 bit to
13212^23-1 (about 8 million) can be specified.</p>
1322
1323<h5>Syntax:</h5>
1324
1325<pre>
1326 iN
1327</pre>
1328
1329<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1330value.</p>
1331
1332<h5>Examples:</h5>
1333<table class="layout">
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]1334 <tbody>
1335 <tr>
1336 <td><tt>i1</tt></td>
1337 <td>a single-bit integer.</td>
1338 </tr><tr>
1339 <td><tt>i32</tt></td>
1340 <td>a 32-bit integer.</td>
1341 </tr><tr>
1342 <td><tt>i1942652</tt></td>
1343 <td>a really big integer of over 1 million bits.</td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1344 </tr>
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]1345 </tbody>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1346</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1347
1348<p>Note that the code generator does not yet support large integer types
1349to be used as function return types. The specific limit on how large a
1350return type the code generator can currently handle is target-dependent;
1351currently it's often 64 bits for 32-bit targets and 128 bits for 64-bit
1352targets.</p>
1353
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1354</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1355
1356<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1357<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1358
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1359<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1360
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1361<h5>Overview:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1362
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1363<p>The array type is a very simple derived type that arranges elements
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1364sequentially in memory. The array type requires a size (number of
1365elements) and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1366
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1367<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1368
1369<pre>
1370 [&lt;# elements&gt; x &lt;elementtype&gt;]
1371</pre>
1372
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1373<p>The number of elements is a constant integer value; elementtype may
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1374be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1375
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1376<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1377<table class="layout">
1378 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1379 <td class="left"><tt>[40 x i32]</tt></td>
1380 <td class="left">Array of 40 32-bit integer values.</td>
1381 </tr>
1382 <tr class="layout">
1383 <td class="left"><tt>[41 x i32]</tt></td>
1384 <td class="left">Array of 41 32-bit integer values.</td>
1385 </tr>
1386 <tr class="layout">
1387 <td class="left"><tt>[4 x i8]</tt></td>
1388 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1389 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1390</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1391<p>Here are some examples of multidimensional arrays:</p>
1392<table class="layout">
1393 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1394 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1395 <td class="left">3x4 array of 32-bit integer values.</td>
1396 </tr>
1397 <tr class="layout">
1398 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1399 <td class="left">12x10 array of single precision floating point values.</td>
1400 </tr>
1401 <tr class="layout">
1402 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1403 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1404 </tr>
1405</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1406
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1407<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1408length array. Normally, accesses past the end of an array are undefined in
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1409LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1410As a special case, however, zero length arrays are recognized to be variable
1411length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1412type "{ i32, [0 x float]}", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1413
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1414<p>Note that the code generator does not yet support large aggregate types
1415to be used as function return types. The specific limit on how large an
1416aggregate return type the code generator can currently handle is
1417target-dependent, and also dependent on the aggregate element types.</p>
1418
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1419</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1420
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1421<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1422<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1423<div class="doc_text">
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1424
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1425<h5>Overview:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1426
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1427<p>The function type can be thought of as a function signature. It
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1428consists of a return type and a list of formal parameter types. The
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1429return 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]1430If 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]1431class types, and the struct must have at least one element.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1432
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1433<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1434
1435<pre>
1436 &lt;returntype list&gt; (&lt;parameter list&gt;)
1437</pre>
1438
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1439<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]1440specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1441which indicates that the function takes a variable number of arguments.
1442Variable argument functions can access their arguments with the <a
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1443 href="#int_varargs">variable argument handling intrinsic</a> functions.
1444'<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1445<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1446
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1447<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1448<table class="layout">
1449 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1450 <td class="left"><tt>i32 (i32)</tt></td>
1451 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1452 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1453 </tr><tr class="layout">
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]1454 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1455 </tt></td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1456 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1457 an <tt>i16</tt> that should be sign extended and a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1458 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1459 <tt>float</tt>.
1460 </td>
1461 </tr><tr class="layout">
1462 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1463 <td class="left">A vararg function that takes at least one
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1464 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1465 which returns an integer. This is the signature for <tt>printf</tt> in
1466 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1467 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1468 </tr><tr class="layout">
1469 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukmanb0a57aa2008-11-27 06:41:20 +0000[diff] [blame]1470 <td class="left">A function taking an <tt>i32</tt>, returning two
1471 <tt>i32</tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1472 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1473 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1474</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1475
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1476</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1477<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1478<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1479<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1480<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1481<p>The structure type is used to represent a collection of data members
1482together in memory. The packing of the field types is defined to match
1483the ABI of the underlying processor. The elements of a structure may
1484be any type that has a size.</p>
1485<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1486and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1487field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1488instruction.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1489<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1490<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1491<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1492<table class="layout">
1493 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1494 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1495 <td class="left">A triple of three <tt>i32</tt> values</td>
1496 </tr><tr class="layout">
1497 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1498 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1499 second element is a <a href="#t_pointer">pointer</a> to a
1500 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1501 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1502 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1503</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1504
1505<p>Note that the code generator does not yet support large aggregate types
1506to be used as function return types. The specific limit on how large an
1507aggregate return type the code generator can currently handle is
1508target-dependent, and also dependent on the aggregate element types.</p>
1509
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1510</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1511
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1512<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1513<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1514</div>
1515<div class="doc_text">
1516<h5>Overview:</h5>
1517<p>The packed structure type is used to represent a collection of data members
1518together in memory. There is no padding between fields. Further, the alignment
1519of a packed structure is 1 byte. The elements of a packed structure may
1520be any type that has a size.</p>
1521<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1522and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1523field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1524instruction.</p>
1525<h5>Syntax:</h5>
1526<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1527<h5>Examples:</h5>
1528<table class="layout">
1529 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1530 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1531 <td class="left">A triple of three <tt>i32</tt> values</td>
1532 </tr><tr class="layout">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1533 <td class="left">
1534<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1535 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1536 second element is a <a href="#t_pointer">pointer</a> to a
1537 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1538 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1539 </tr>
1540</table>
1541</div>
1542
1543<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1544<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1545<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1546<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1547<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]1548reference to another object, which must live in memory. Pointer types may have
1549an optional address space attribute defining the target-specific numbered
1550address space where the pointed-to object resides. The default address space is
1551zero.</p>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1552<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1553<pre> &lt;type&gt; *<br></pre>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1554<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1555<table class="layout">
1556 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]1557 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1558 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1559 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1560 </tr>
1561 <tr class="layout">
1562 <td class="left"><tt>i32 (i32 *) *</tt></td>
1563 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1564 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1565 <tt>i32</tt>.</td>
1566 </tr>
1567 <tr class="layout">
1568 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1569 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1570 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1571 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1572</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1573</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1574
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1575<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1576<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1577<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1578
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1579<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1580
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1581<p>A vector type is a simple derived type that represents a vector
1582of elements. Vector types are used when multiple primitive data
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1583are operated in parallel using a single instruction (SIMD).
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1584A vector type requires a size (number of
Chris Lattnerb8d172f2005-11-10 01:44:22 +0000[diff] [blame]1585elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1586of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1587considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1588
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1589<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1590
1591<pre>
1592 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1593</pre>
1594
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1595<p>The number of elements is a constant integer value; elementtype may
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1596be any integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1597
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1598<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1599
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1600<table class="layout">
1601 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1602 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1603 <td class="left">Vector of 4 32-bit integer values.</td>
1604 </tr>
1605 <tr class="layout">
1606 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1607 <td class="left">Vector of 8 32-bit floating-point values.</td>
1608 </tr>
1609 <tr class="layout">
1610 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1611 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1612 </tr>
1613</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1614
1615<p>Note that the code generator does not yet support large vector types
1616to be used as function return types. The specific limit on how large a
1617vector return type codegen can currently handle is target-dependent;
1618currently it's often a few times longer than a hardware vector register.</p>
1619
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1620</div>
1621
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1622<!-- _______________________________________________________________________ -->
1623<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1624<div class="doc_text">
1625
1626<h5>Overview:</h5>
1627
1628<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksen8ac04ff2007-10-14 00:34:53 +0000[diff] [blame]1629corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1630In LLVM, opaque types can eventually be resolved to any type (not just a
1631structure type).</p>
1632
1633<h5>Syntax:</h5>
1634
1635<pre>
1636 opaque
1637</pre>
1638
1639<h5>Examples:</h5>
1640
1641<table class="layout">
1642 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1643 <td class="left"><tt>opaque</tt></td>
1644 <td class="left">An opaque type.</td>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1645 </tr>
1646</table>
1647</div>
1648
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1649<!-- ======================================================================= -->
1650<div class="doc_subsection">
1651 <a name="t_uprefs">Type Up-references</a>
1652</div>
1653
1654<div class="doc_text">
1655<h5>Overview:</h5>
1656<p>
1657An "up reference" allows you to refer to a lexically enclosing type without
1658requiring it to have a name. For instance, a structure declaration may contain a
1659pointer to any of the types it is lexically a member of. Example of up
1660references (with their equivalent as named type declarations) include:</p>
1661
1662<pre>
1663 { \2 * } %x = type { %t* }
1664 { \2 }* %y = type { %y }*
1665 \1* %z = type %z*
1666</pre>
1667
1668<p>
1669An up reference is needed by the asmprinter for printing out cyclic types when
1670there is no declared name for a type in the cycle. Because the asmprinter does
1671not want to print out an infinite type string, it needs a syntax to handle
1672recursive types that have no names (all names are optional in llvm IR).
1673</p>
1674
1675<h5>Syntax:</h5>
1676<pre>
1677 \&lt;level&gt;
1678</pre>
1679
1680<p>
1681The level is the count of the lexical type that is being referred to.
1682</p>
1683
1684<h5>Examples:</h5>
1685
1686<table class="layout">
1687 <tr class="layout">
1688 <td class="left"><tt>\1*</tt></td>
1689 <td class="left">Self-referential pointer.</td>
1690 </tr>
1691 <tr class="layout">
1692 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
1693 <td class="left">Recursive structure where the upref refers to the out-most
1694 structure.</td>
1695 </tr>
1696</table>
1697</div>
1698
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1699
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1700<!-- *********************************************************************** -->
1701<div class="doc_section"> <a name="constants">Constants</a> </div>
1702<!-- *********************************************************************** -->
1703
1704<div class="doc_text">
1705
1706<p>LLVM has several different basic types of constants. This section describes
1707them all and their syntax.</p>
1708
1709</div>
1710
1711<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1712<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1713
1714<div class="doc_text">
1715
1716<dl>
1717 <dt><b>Boolean constants</b></dt>
1718
1719 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1720 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1721 </dd>
1722
1723 <dt><b>Integer constants</b></dt>
1724
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1725 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1726 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1727 integer types.
1728 </dd>
1729
1730 <dt><b>Floating point constants</b></dt>
1731
1732 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1733 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]1734 notation (see below). The assembler requires the exact decimal value of
1735 a floating-point constant. For example, the assembler accepts 1.25 but
1736 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1737 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1738
1739 <dt><b>Null pointer constants</b></dt>
1740
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1741 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1742 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1743
1744</dl>
1745
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1746<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1747of floating point constants. For example, the form '<tt>double
17480x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
17494.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1750(and the only time that they are generated by the disassembler) is when a
1751floating point constant must be emitted but it cannot be represented as a
1752decimal floating point number. For example, NaN's, infinities, and other
1753special values are represented in their IEEE hexadecimal format so that
1754assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1755
1756</div>
1757
1758<!-- ======================================================================= -->
1759<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1760</div>
1761
1762<div class="doc_text">
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]1763<p>Aggregate constants arise from aggregation of simple constants
1764and smaller aggregate constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1765
1766<dl>
1767 <dt><b>Structure constants</b></dt>
1768
1769 <dd>Structure constants are represented with notation similar to structure
1770 type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner64910ee2007-12-25 20:34:52 +0000[diff] [blame]1771 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1772 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]1773 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1774 types of elements must match those specified by the type.
1775 </dd>
1776
1777 <dt><b>Array constants</b></dt>
1778
1779 <dd>Array constants are represented with notation similar to array type
1780 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1781 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1782 constants must have <a href="#t_array">array type</a>, and the number and
1783 types of elements must match those specified by the type.
1784 </dd>
1785
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1786 <dt><b>Vector constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1787
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1788 <dd>Vector constants are represented with notation similar to vector type
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1789 definitions (a comma separated list of elements, surrounded by
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1790 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]1791 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1792 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1793 match those specified by the type.
1794 </dd>
1795
1796 <dt><b>Zero initialization</b></dt>
1797
1798 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1799 value to zero of <em>any</em> type, including scalar and aggregate types.
1800 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]1801 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1802 initializers.
1803 </dd>
1804</dl>
1805
1806</div>
1807
1808<!-- ======================================================================= -->
1809<div class="doc_subsection">
1810 <a name="globalconstants">Global Variable and Function Addresses</a>
1811</div>
1812
1813<div class="doc_text">
1814
1815<p>The addresses of <a href="#globalvars">global variables</a> and <a
1816href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1817constants. These constants are explicitly referenced when the <a
1818href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1819href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1820file:</p>
1821
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1822<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1823<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]1824@X = global i32 17
1825@Y = global i32 42
1826@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1827</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1828</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1829
1830</div>
1831
1832<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1833<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1834<div class="doc_text">
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1835 <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]1836 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1837 a constant is permitted.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1838
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1839 <p>Undefined values indicate to the compiler that the program is well defined
1840 no matter what value is used, giving the compiler more freedom to optimize.
1841 </p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1842</div>
1843
1844<!-- ======================================================================= -->
1845<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1846</div>
1847
1848<div class="doc_text">
1849
1850<p>Constant expressions are used to allow expressions involving other constants
1851to be used as constants. Constant expressions may be of any <a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1852href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1853that does not have side effects (e.g. load and call are not supported). The
1854following is the syntax for constant expressions:</p>
1855
1856<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1857 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1858 <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]1859 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1860
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1861 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1862 <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]1863 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]1864
1865 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1866 <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]1867 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]1868
1869 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1870 <dd>Truncate a floating point constant to another floating point type. The
1871 size of CST must be larger than the size of TYPE. Both types must be
1872 floating point.</dd>
1873
1874 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1875 <dd>Floating point extend a constant to another type. The size of CST must be
1876 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1877
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]1878 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1879 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1880 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1881 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1882 of the same number of elements. If the value won't fit in the integer type,
1883 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1884
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1885 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1886 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1887 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1888 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1889 of the same number of elements. If the value won't fit in the integer type,
1890 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1891
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1892 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1893 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1894 constant. TYPE must be a scalar or vector floating point type. CST must be of
1895 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1896 of the same number of elements. If the value won't fit in the floating point
1897 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1898
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1899 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1900 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1901 constant. TYPE must be a scalar or vector floating point type. CST must be of
1902 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1903 of the same number of elements. If the value won't fit in the floating point
1904 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1905
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1906 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1907 <dd>Convert a pointer typed constant to the corresponding integer constant
1908 TYPE must be an integer type. CST must be of pointer type. The CST value is
1909 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1910
1911 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1912 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1913 pointer type. CST must be of integer type. The CST value is zero extended,
1914 truncated, or unchanged to make it fit in a pointer size. This one is
1915 <i>really</i> dangerous!</dd>
1916
1917 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1918 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1919 identical (same number of bits). The conversion is done as if the CST value
1920 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]1921 with this operator, just the type. This can be used for conversion of
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1922 vector types to any other type, as long as they have the same bit width. For
Dan Gohman500233a2008-09-08 16:45:59 +0000[diff] [blame]1923 pointers it is only valid to cast to another pointer type. It is not valid
1924 to bitcast to or from an aggregate type.
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1925 </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1926
1927 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1928
1929 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1930 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1931 instruction, the index list may have zero or more indexes, which are required
1932 to make sense for the type of "CSTPTR".</dd>
1933
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1934 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1935
1936 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1937 constants.</dd>
1938
1939 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1940 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1941
1942 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1943 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1944
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]1945 <dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
1946 <dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
1947
1948 <dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
1949 <dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
1950
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1951 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1952
1953 <dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1954 operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1955
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1956 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1957
1958 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1959 operation</a> on constants.</dd>
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1960
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1961
1962 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1963
1964 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1965 operation</a> on constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1966
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1967 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1968
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1969 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1970 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1971 binary</a> operations. The constraints on operands are the same as those for
1972 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1973 values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1974</dl>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1975</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]1976
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1977<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1978<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1979<!-- *********************************************************************** -->
1980
1981<!-- ======================================================================= -->
1982<div class="doc_subsection">
1983<a name="inlineasm">Inline Assembler Expressions</a>
1984</div>
1985
1986<div class="doc_text">
1987
1988<p>
1989LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1990Module-Level Inline Assembly</a>) through the use of a special value. This
1991value represents the inline assembler as a string (containing the instructions
1992to emit), a list of operand constraints (stored as a string), and a flag that
1993indicates whether or not the inline asm expression has side effects. An example
1994inline assembler expression is:
1995</p>
1996
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1997<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1998<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1999i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2000</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2001</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2002
2003<p>
2004Inline assembler expressions may <b>only</b> be used as the callee operand of
2005a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
2006</p>
2007
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2008<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2009<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2010%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]2011</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2012</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2013
2014<p>
2015Inline asms with side effects not visible in the constraint list must be marked
2016as having side effects. This is done through the use of the
2017'<tt>sideeffect</tt>' keyword, like so:
2018</p>
2019
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2020<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2021<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2022call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2023</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2024</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2025
2026<p>TODO: The format of the asm and constraints string still need to be
2027documented here. Constraints on what can be done (e.g. duplication, moving, etc
Chris Lattner4f993352008-10-04 18:36:02 +0000[diff] [blame]2028need to be documented). This is probably best done by reference to another
2029document that covers inline asm from a holistic perspective.
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2030</p>
2031
2032</div>
2033
2034<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2035<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
2036<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2037
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2038<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2039
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2040<p>The LLVM instruction set consists of several different
2041classifications of instructions: <a href="#terminators">terminator
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2042instructions</a>, <a href="#binaryops">binary instructions</a>,
2043<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2044 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
2045instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2046
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2047</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2048
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2049<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2050<div class="doc_subsection"> <a name="terminators">Terminator
2051Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2052
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2053<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2054
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2055<p>As mentioned <a href="#functionstructure">previously</a>, every
2056basic block in a program ends with a "Terminator" instruction, which
2057indicates which block should be executed after the current block is
2058finished. These terminator instructions typically yield a '<tt>void</tt>'
2059value: they produce control flow, not values (the one exception being
2060the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2061<p>There are six different terminator instructions: the '<a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2062 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
2063instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2064the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
2065 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
2066 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2067
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2068</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2069
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2070<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2071<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
2072Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2073<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2074<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2075<pre>
2076 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]2077 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2078</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2079
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2080<h5>Overview:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2081
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2082<p>The '<tt>ret</tt>' instruction is used to return control flow (and
2083optionally a value) from a function back to the caller.</p>
John Criswell4457dc92004-04-09 16:48:45 +0000[diff] [blame]2084<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2085returns a value and then causes control flow, and one that just causes
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2086control flow to occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2087
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2088<h5>Arguments:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2089
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2090<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
2091the return value. The type of the return value must be a
2092'<a href="#t_firstclass">first class</a>' type.</p>
2093
2094<p>A function is not <a href="#wellformed">well formed</a> if
2095it it has a non-void return type and contains a '<tt>ret</tt>'
2096instruction with no return value or a return value with a type that
2097does not match its type, or if it has a void return type and contains
2098a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2099
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2100<h5>Semantics:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2101
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2102<p>When the '<tt>ret</tt>' instruction is executed, control flow
2103returns back to the calling function's context. If the caller is a "<a
John Criswellfa081872004-06-25 15:16:57 +0000[diff] [blame]2104 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2105the instruction after the call. If the caller was an "<a
2106 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2107at the beginning of the "normal" destination block. If the instruction
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2108returns a value, that value shall set the call or invoke instruction's
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]2109return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2110
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2111<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2112
2113<pre>
2114 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2115 ret void <i>; Return from a void function</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2116 ret { i32, i8 } { i32 4, i8 2 } <i>; Return an aggregate of values 4 and 2</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2117</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2118
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]2119<p>Note that the code generator does not yet fully support large
2120 return values. The specific sizes that are currently supported are
2121 dependent on the target. For integers, on 32-bit targets the limit
2122 is often 64 bits, and on 64-bit targets the limit is often 128 bits.
2123 For aggregate types, the current limits are dependent on the element
2124 types; for example targets are often limited to 2 total integer
2125 elements and 2 total floating-point elements.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2126
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2127</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2128<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2129<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2130<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2131<h5>Syntax:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2132<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]2133</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2134<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2135<p>The '<tt>br</tt>' instruction is used to cause control flow to
2136transfer to a different basic block in the current function. There are
2137two forms of this instruction, corresponding to a conditional branch
2138and an unconditional branch.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2139<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2140<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2141single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]2142unconditional form of the '<tt>br</tt>' instruction takes a single
2143'<tt>label</tt>' value as a target.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2144<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2145<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2146argument is evaluated. If the value is <tt>true</tt>, control flows
2147to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2148control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2149<h5>Example:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2150<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]2151 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]2152</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2153<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2154<div class="doc_subsubsection">
2155 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2156</div>
2157
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2158<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2159<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2160
2161<pre>
2162 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2163</pre>
2164
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2165<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2166
2167<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
2168several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2169instruction, allowing a branch to occur to one of many possible
2170destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2171
2172
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2173<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2174
2175<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
2176comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
2177an array of pairs of comparison value constants and '<tt>label</tt>'s. The
2178table is not allowed to contain duplicate constant entries.</p>
2179
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2180<h5>Semantics:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2181
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2182<p>The <tt>switch</tt> instruction specifies a table of values and
2183destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]2184table is searched for the given value. If the value is found, control flow is
2185transfered to the corresponding destination; otherwise, control flow is
2186transfered to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2187
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2188<h5>Implementation:</h5>
2189
2190<p>Depending on properties of the target machine and the particular
2191<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]2192ways. For example, it could be generated as a series of chained conditional
2193branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2194
2195<h5>Example:</h5>
2196
2197<pre>
2198 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2199 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2200 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2201
2202 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2203 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2204
2205 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2206 switch i32 %val, label %otherwise [ i32 0, label %onzero
2207 i32 1, label %onone
2208 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2209</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2210</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2211
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2212<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2213<div class="doc_subsubsection">
2214 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2215</div>
2216
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2217<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2218
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2219<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2220
2221<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2222 &lt;result&gt; = invoke [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] &lt;ptr to function ty&gt; &lt;function ptr val&gt;(&lt;function args&gt;) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner76b8a332006-05-14 18:23:06 +0000[diff] [blame]2223 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2224</pre>
2225
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2226<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2227
2228<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
2229function, with the possibility of control flow transfer to either the
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2230'<tt>normal</tt>' label or the
2231'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2232"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
2233"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2234href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]2235continued at the dynamically nearest "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2236
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2237<h5>Arguments:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2238
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2239<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2240
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2241<ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2242 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]2243 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2244 convention</a> the call should use. If none is specified, the call defaults
2245 to using C calling conventions.
2246 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2247
2248 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
2249 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
2250 and '<tt>inreg</tt>' attributes are valid here.</li>
2251
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2252 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
2253 function value being invoked. In most cases, this is a direct function
2254 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
2255 an arbitrary pointer to function value.
2256 </li>
2257
2258 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
2259 function to be invoked. </li>
2260
2261 <li>'<tt>function args</tt>': argument list whose types match the function
2262 signature argument types. If the function signature indicates the function
2263 accepts a variable number of arguments, the extra arguments can be
2264 specified. </li>
2265
2266 <li>'<tt>normal label</tt>': the label reached when the called function
2267 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
2268
2269 <li>'<tt>exception label</tt>': the label reached when a callee returns with
2270 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
2271
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2272 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2273 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2274 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2275</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2276
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2277<h5>Semantics:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2278
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2279<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2280href="#i_call">call</a></tt>' instruction in most regards. The primary
2281difference is that it establishes an association with a label, which is used by
2282the runtime library to unwind the stack.</p>
2283
2284<p>This instruction is used in languages with destructors to ensure that proper
2285cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2286exception. Additionally, this is important for implementation of
2287'<tt>catch</tt>' clauses in high-level languages that support them.</p>
2288
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2289<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2290<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2291 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2292 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2293 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2294 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2295</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2296</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2297
2298
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2299<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2300
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2301<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2302Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2303
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2304<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2305
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2306<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2307<pre>
2308 unwind
2309</pre>
2310
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2311<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2312
2313<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
2314at the first callee in the dynamic call stack which used an <a
2315href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
2316primarily used to implement exception handling.</p>
2317
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2318<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2319
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]2320<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2321immediately halt. The dynamic call stack is then searched for the first <a
2322href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
2323execution continues at the "exceptional" destination block specified by the
2324<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
2325dynamic call chain, undefined behavior results.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2326</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2327
2328<!-- _______________________________________________________________________ -->
2329
2330<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2331Instruction</a> </div>
2332
2333<div class="doc_text">
2334
2335<h5>Syntax:</h5>
2336<pre>
2337 unreachable
2338</pre>
2339
2340<h5>Overview:</h5>
2341
2342<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
2343instruction is used to inform the optimizer that a particular portion of the
2344code is not reachable. This can be used to indicate that the code after a
2345no-return function cannot be reached, and other facts.</p>
2346
2347<h5>Semantics:</h5>
2348
2349<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
2350</div>
2351
2352
2353
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2354<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2355<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2356<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2357<p>Binary operators are used to do most of the computation in a
Chris Lattner5a158142008-04-01 18:47:32 +0000[diff] [blame]2358program. They require two operands of the same type, execute an operation on them, and
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2359produce a single value. The operands might represent
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2360multiple 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]2361The result value has the same type as its operands.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2362<p>There are several different binary operators:</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2363</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2364<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2365<div class="doc_subsubsection">
2366 <a name="i_add">'<tt>add</tt>' Instruction</a>
2367</div>
2368
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2369<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2370
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2371<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2372
2373<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2374 &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]2375</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2376
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2377<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2378
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2379<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2380
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2381<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2382
2383<p>The two arguments to the '<tt>add</tt>' instruction must be <a
2384 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
2385 <a href="#t_vector">vector</a> values. Both arguments must have identical
2386 types.</p>
2387
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2388<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2389
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2390<p>The value produced is the integer or floating point sum of the two
2391operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2392
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2393<p>If an integer sum has unsigned overflow, the result returned is the
2394mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2395the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2396
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2397<p>Because LLVM integers use a two's complement representation, this
2398instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2399
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2400<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2401
2402<pre>
2403 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2404</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2405</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2406<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2407<div class="doc_subsubsection">
2408 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2409</div>
2410
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2411<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2412
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2413<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2414
2415<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2416 &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]2417</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2418
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2419<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2420
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2421<p>The '<tt>sub</tt>' instruction returns the difference of its two
2422operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2423
2424<p>Note that the '<tt>sub</tt>' instruction is used to represent the
2425'<tt>neg</tt>' instruction present in most other intermediate
2426representations.</p>
2427
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2428<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2429
2430<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
2431 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2432 or <a href="#t_vector">vector</a> values. Both arguments must have identical
2433 types.</p>
2434
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2435<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2436
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2437<p>The value produced is the integer or floating point difference of
2438the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2439
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2440<p>If an integer difference has unsigned overflow, the result returned is the
2441mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2442the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2443
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2444<p>Because LLVM integers use a two's complement representation, this
2445instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2446
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2447<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2448<pre>
2449 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2450 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2451</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2452</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2453
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2454<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2455<div class="doc_subsubsection">
2456 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2457</div>
2458
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2459<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2460
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2461<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2462<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]2463</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2464<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2465<p>The '<tt>mul</tt>' instruction returns the product of its two
2466operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2467
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2468<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2469
2470<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
2471href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2472or <a href="#t_vector">vector</a> values. Both arguments must have identical
2473types.</p>
2474
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2475<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2476
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2477<p>The value produced is the integer or floating point product of the
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2478two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2479
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2480<p>If the result of an integer multiplication has unsigned overflow,
2481the result returned is the mathematical result modulo
24822<sup>n</sup>, where n is the bit width of the result.</p>
2483<p>Because LLVM integers use a two's complement representation, and the
2484result is the same width as the operands, this instruction returns the
2485correct result for both signed and unsigned integers. If a full product
2486(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
2487should be sign-extended or zero-extended as appropriate to the
2488width of the full product.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2489<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2490<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]2491</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2492</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2493
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2494<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2495<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2496</a></div>
2497<div class="doc_text">
2498<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2499<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]2500</pre>
2501<h5>Overview:</h5>
2502<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2503operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2504
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2505<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2506
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2507<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2508<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2509values. Both arguments must have identical types.</p>
2510
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2511<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2512
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2513<p>The value produced is the unsigned integer quotient of the two operands.</p>
2514<p>Note that unsigned integer division and signed integer division are distinct
2515operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2516<p>Division by zero leads to undefined behavior.</p>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2517<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2518<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]2519</pre>
2520</div>
2521<!-- _______________________________________________________________________ -->
2522<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2523</a> </div>
2524<div class="doc_text">
2525<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2526<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2527 &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]2528</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2529
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2530<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2531
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2532<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2533operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2534
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2535<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2536
2537<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2538<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2539values. Both arguments must have identical types.</p>
2540
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2541<h5>Semantics:</h5>
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2542<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]2543<p>Note that signed integer division and unsigned integer division are distinct
2544operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2545<p>Division by zero leads to undefined behavior. Overflow also leads to
2546undefined behavior; this is a rare case, but can occur, for example,
2547by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2548<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2549<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]2550</pre>
2551</div>
2552<!-- _______________________________________________________________________ -->
2553<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2554Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2555<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2556<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2557<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2558 &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]2559</pre>
2560<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2561
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2562<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2563operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2564
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2565<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2566
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2567<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2568<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2569of floating point values. Both arguments must have identical types.</p>
2570
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2571<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2572
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2573<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2574
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2575<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2576
2577<pre>
2578 &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]2579</pre>
2580</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2581
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2582<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2583<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2584</div>
2585<div class="doc_text">
2586<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2587<pre> &lt;result&gt; = 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]2588</pre>
2589<h5>Overview:</h5>
2590<p>The '<tt>urem</tt>' instruction returns the remainder from the
2591unsigned division of its two arguments.</p>
2592<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2593<p>The two arguments to the '<tt>urem</tt>' instruction must be
2594<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2595values. Both arguments must have identical types.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2596<h5>Semantics:</h5>
2597<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2598This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2599<p>Note that unsigned integer remainder and signed integer remainder are
2600distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
2601<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2602<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2603<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]2604</pre>
2605
2606</div>
2607<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2608<div class="doc_subsubsection">
2609 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
2610</div>
2611
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2612<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2613
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2614<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2615
2616<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2617 &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]2618</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2619
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2620<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2621
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2622<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2623signed division of its two operands. This instruction can also take
2624<a href="#t_vector">vector</a> versions of the values in which case
2625the elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]2626
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2627<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2628
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2629<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2630<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2631values. Both arguments must have identical types.</p>
2632
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2633<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2634
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2635<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2636has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
2637operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2638a value. For more information about the difference, see <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2639 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2640Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencer64f5c6c2007-03-24 22:40:44 +0000[diff] [blame]2641please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2642Wikipedia: modulo operation</a>.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2643<p>Note that signed integer remainder and unsigned integer remainder are
2644distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
2645<p>Taking the remainder of a division by zero leads to undefined behavior.
2646Overflow also leads to undefined behavior; this is a rare case, but can occur,
2647for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
2648(The remainder doesn't actually overflow, but this rule lets srem be
2649implemented using instructions that return both the result of the division
2650and the remainder.)</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2651<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2652<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]2653</pre>
2654
2655</div>
2656<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2657<div class="doc_subsubsection">
2658 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
2659
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2660<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2661
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2662<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2663<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]2664</pre>
2665<h5>Overview:</h5>
2666<p>The '<tt>frem</tt>' instruction returns the remainder from the
2667division of its two operands.</p>
2668<h5>Arguments:</h5>
2669<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2670<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2671of floating point values. Both arguments must have identical types.</p>
2672
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2673<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2674
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2675<p>This instruction returns the <i>remainder</i> of a division.
2676The remainder has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2677
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2678<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2679
2680<pre>
2681 &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]2682</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2683</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]2684
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2685<!-- ======================================================================= -->
2686<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2687Operations</a> </div>
2688<div class="doc_text">
2689<p>Bitwise binary operators are used to do various forms of
2690bit-twiddling in a program. They are generally very efficient
2691instructions and can commonly be strength reduced from other
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2692instructions. They require two operands of the same type, execute an operation on them,
2693and 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]2694</div>
2695
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2696<!-- _______________________________________________________________________ -->
2697<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2698Instruction</a> </div>
2699<div class="doc_text">
2700<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2701<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]2702</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2703
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2704<h5>Overview:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2705
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2706<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2707the left a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2708
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2709<h5>Arguments:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2710
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2711<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2712 href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2713type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2714
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2715<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2716
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2717<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
2718where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
Mon P Wang01f8d092008-12-10 08:55:09 +0000[diff] [blame]2719equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
2720If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
2721corresponding shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2722
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2723<h5>Example:</h5><pre>
2724 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2725 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2726 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2727 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]2728 &lt;result&gt; = shl &lt;2 x i32&gt; &lt; i32 1, i32 1&gt;, &lt; i32 1, i32 2&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 2, i32 4&gt;</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2729</pre>
2730</div>
2731<!-- _______________________________________________________________________ -->
2732<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2733Instruction</a> </div>
2734<div class="doc_text">
2735<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2736<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]2737</pre>
2738
2739<h5>Overview:</h5>
2740<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2741operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2742
2743<h5>Arguments:</h5>
2744<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2745<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]2746type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2747
2748<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2749
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2750<p>This instruction always performs a logical shift right operation. The most
2751significant bits of the result will be filled with zero bits after the
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2752shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
Mon P Wang01f8d092008-12-10 08:55:09 +0000[diff] [blame]2753the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
2754vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
2755amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2756
2757<h5>Example:</h5>
2758<pre>
2759 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2760 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2761 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2762 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2763 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]2764 &lt;result&gt; = lshr &lt;2 x i32&gt; &lt; i32 -2, i32 4&gt;, &lt; i32 1, i32 2&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0x7FFFFFFF, i32 1&gt;</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2765</pre>
2766</div>
2767
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2768<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2769<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2770Instruction</a> </div>
2771<div class="doc_text">
2772
2773<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2774<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]2775</pre>
2776
2777<h5>Overview:</h5>
2778<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2779operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2780
2781<h5>Arguments:</h5>
2782<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2783<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]2784type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2785
2786<h5>Semantics:</h5>
2787<p>This instruction always performs an arithmetic shift right operation,
2788The most significant bits of the result will be filled with the sign bit
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2789of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
Mon P Wang01f8d092008-12-10 08:55:09 +0000[diff] [blame]2790larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
2791arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
2792corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2793
2794<h5>Example:</h5>
2795<pre>
2796 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2797 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2798 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2799 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2800 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]2801 &lt;result&gt; = ashr &lt;2 x i32&gt; &lt; i32 -2, i32 4&gt;, &lt; i32 1, i32 3&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 -1, i32 0&gt;</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2802</pre>
2803</div>
2804
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2805<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2806<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2807Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2808
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2809<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2810
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2811<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2812
2813<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2814 &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]2815</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2816
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2817<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2818
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2819<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2820its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2821
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2822<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2823
2824<p>The two arguments to the '<tt>and</tt>' instruction must be
2825<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2826values. Both arguments must have identical types.</p>
2827
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2828<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2829<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2830<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2831<div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2832<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2833 <tbody>
2834 <tr>
2835 <td>In0</td>
2836 <td>In1</td>
2837 <td>Out</td>
2838 </tr>
2839 <tr>
2840 <td>0</td>
2841 <td>0</td>
2842 <td>0</td>
2843 </tr>
2844 <tr>
2845 <td>0</td>
2846 <td>1</td>
2847 <td>0</td>
2848 </tr>
2849 <tr>
2850 <td>1</td>
2851 <td>0</td>
2852 <td>0</td>
2853 </tr>
2854 <tr>
2855 <td>1</td>
2856 <td>1</td>
2857 <td>1</td>
2858 </tr>
2859 </tbody>
2860</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2861</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2862<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2863<pre>
2864 &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]2865 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2866 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2867</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2868</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2869<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2870<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2871<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2872<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2873<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]2874</pre>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2875<h5>Overview:</h5>
2876<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2877or of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2878<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2879
2880<p>The two arguments to the '<tt>or</tt>' instruction must be
2881<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2882values. Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2883<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2884<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2885<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2886<div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2887<table border="1" cellspacing="0" cellpadding="4">
2888 <tbody>
2889 <tr>
2890 <td>In0</td>
2891 <td>In1</td>
2892 <td>Out</td>
2893 </tr>
2894 <tr>
2895 <td>0</td>
2896 <td>0</td>
2897 <td>0</td>
2898 </tr>
2899 <tr>
2900 <td>0</td>
2901 <td>1</td>
2902 <td>1</td>
2903 </tr>
2904 <tr>
2905 <td>1</td>
2906 <td>0</td>
2907 <td>1</td>
2908 </tr>
2909 <tr>
2910 <td>1</td>
2911 <td>1</td>
2912 <td>1</td>
2913 </tr>
2914 </tbody>
2915</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2916</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2917<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2918<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2919 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2920 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2921</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2922</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2923<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2924<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2925Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2926<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2927<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2928<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]2929</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2930<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2931<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2932or of its two operands. The <tt>xor</tt> is used to implement the
2933"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2934<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2935<p>The two arguments to the '<tt>xor</tt>' instruction must be
2936<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2937values. Both arguments must have identical types.</p>
2938
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2939<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2940
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2941<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2942<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2943<div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2944<table border="1" cellspacing="0" cellpadding="4">
2945 <tbody>
2946 <tr>
2947 <td>In0</td>
2948 <td>In1</td>
2949 <td>Out</td>
2950 </tr>
2951 <tr>
2952 <td>0</td>
2953 <td>0</td>
2954 <td>0</td>
2955 </tr>
2956 <tr>
2957 <td>0</td>
2958 <td>1</td>
2959 <td>1</td>
2960 </tr>
2961 <tr>
2962 <td>1</td>
2963 <td>0</td>
2964 <td>1</td>
2965 </tr>
2966 <tr>
2967 <td>1</td>
2968 <td>1</td>
2969 <td>0</td>
2970 </tr>
2971 </tbody>
2972</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2973</div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2974<p> </p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2975<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2976<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2977 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2978 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2979 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2980</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2981</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2982
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2983<!-- ======================================================================= -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2984<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2985 <a name="vectorops">Vector Operations</a>
2986</div>
2987
2988<div class="doc_text">
2989
2990<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2991target-independent manner. These instructions cover the element-access and
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2992vector-specific operations needed to process vectors effectively. While LLVM
2993does directly support these vector operations, many sophisticated algorithms
2994will want to use target-specific intrinsics to take full advantage of a specific
2995target.</p>
2996
2997</div>
2998
2999<!-- _______________________________________________________________________ -->
3000<div class="doc_subsubsection">
3001 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
3002</div>
3003
3004<div class="doc_text">
3005
3006<h5>Syntax:</h5>
3007
3008<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3009 &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]3010</pre>
3011
3012<h5>Overview:</h5>
3013
3014<p>
3015The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3016element from a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3017</p>
3018
3019
3020<h5>Arguments:</h5>
3021
3022<p>
3023The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3024value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3025an index indicating the position from which to extract the element.
3026The index may be a variable.</p>
3027
3028<h5>Semantics:</h5>
3029
3030<p>
3031The result is a scalar of the same type as the element type of
3032<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
3033<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3034results are undefined.
3035</p>
3036
3037<h5>Example:</h5>
3038
3039<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3040 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3041</pre>
3042</div>
3043
3044
3045<!-- _______________________________________________________________________ -->
3046<div class="doc_subsubsection">
3047 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
3048</div>
3049
3050<div class="doc_text">
3051
3052<h5>Syntax:</h5>
3053
3054<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]3055 &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]3056</pre>
3057
3058<h5>Overview:</h5>
3059
3060<p>
3061The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3062element into a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3063</p>
3064
3065
3066<h5>Arguments:</h5>
3067
3068<p>
3069The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3070value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3071scalar value whose type must equal the element type of the first
3072operand. The third operand is an index indicating the position at
3073which to insert the value. The index may be a variable.</p>
3074
3075<h5>Semantics:</h5>
3076
3077<p>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3078The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3079element values are those of <tt>val</tt> except at position
3080<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
3081exceeds the length of <tt>val</tt>, the results are undefined.
3082</p>
3083
3084<h5>Example:</h5>
3085
3086<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3087 %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]3088</pre>
3089</div>
3090
3091<!-- _______________________________________________________________________ -->
3092<div class="doc_subsubsection">
3093 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3094</div>
3095
3096<div class="doc_text">
3097
3098<h5>Syntax:</h5>
3099
3100<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3101 &lt;result&gt; = shufflevector &lt;n x &lt;ty&gt;&gt; &lt;v1&gt;, &lt;n x &lt;ty&gt;&gt; &lt;v2&gt;, &lt;m x i32&gt; &lt;mask&gt; <i>; yields &lt;m x &lt;ty&gt;&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3102</pre>
3103
3104<h5>Overview:</h5>
3105
3106<p>
3107The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3108from two input vectors, returning a vector with the same element type as
3109the input and length that is the same as the shuffle mask.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3110</p>
3111
3112<h5>Arguments:</h5>
3113
3114<p>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3115The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
3116with types that match each other. The third argument is a shuffle mask whose
3117element type is always 'i32'. The result of the instruction is a vector whose
3118length is the same as the shuffle mask and whose element type is the same as
3119the element type of the first two operands.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3120</p>
3121
3122<p>
3123The shuffle mask operand is required to be a constant vector with either
3124constant integer or undef values.
3125</p>
3126
3127<h5>Semantics:</h5>
3128
3129<p>
3130The elements of the two input vectors are numbered from left to right across
3131both of the vectors. The shuffle mask operand specifies, for each element of
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3132the result vector, which element of the two input vectors the result element
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3133gets. The element selector may be undef (meaning "don't care") and the second
3134operand may be undef if performing a shuffle from only one vector.
3135</p>
3136
3137<h5>Example:</h5>
3138
3139<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3140 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3141 &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]3142 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
3143 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i> - Identity shuffle.
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3144 %result = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
3145 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
3146 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
3147 &lt;8 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7 &gt; <i>; yields &lt;8 x i32&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3148</pre>
3149</div>
3150
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]3151
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3152<!-- ======================================================================= -->
3153<div class="doc_subsection">
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3154 <a name="aggregateops">Aggregate Operations</a>
3155</div>
3156
3157<div class="doc_text">
3158
3159<p>LLVM supports several instructions for working with aggregate values.
3160</p>
3161
3162</div>
3163
3164<!-- _______________________________________________________________________ -->
3165<div class="doc_subsubsection">
3166 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3167</div>
3168
3169<div class="doc_text">
3170
3171<h5>Syntax:</h5>
3172
3173<pre>
3174 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3175</pre>
3176
3177<h5>Overview:</h5>
3178
3179<p>
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3180The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3181or array element from an aggregate value.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3182</p>
3183
3184
3185<h5>Arguments:</h5>
3186
3187<p>
3188The first operand of an '<tt>extractvalue</tt>' instruction is a
3189value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3190type. The operands are constant indices to specify which value to extract
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3191in a similar manner as indices in a
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3192'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3193</p>
3194
3195<h5>Semantics:</h5>
3196
3197<p>
3198The result is the value at the position in the aggregate specified by
3199the index operands.
3200</p>
3201
3202<h5>Example:</h5>
3203
3204<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3205 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3206</pre>
3207</div>
3208
3209
3210<!-- _______________________________________________________________________ -->
3211<div class="doc_subsubsection">
3212 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3213</div>
3214
3215<div class="doc_text">
3216
3217<h5>Syntax:</h5>
3218
3219<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3220 &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]3221</pre>
3222
3223<h5>Overview:</h5>
3224
3225<p>
3226The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3227into a struct field or array element in an aggregate.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3228</p>
3229
3230
3231<h5>Arguments:</h5>
3232
3233<p>
3234The first operand of an '<tt>insertvalue</tt>' instruction is a
3235value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
3236The second operand is a first-class value to insert.
Dan Gohmanc4b49eb2008-05-23 21:53:15 +0000[diff] [blame]3237The following operands are constant indices
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3238indicating the position at which to insert the value in a similar manner as
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3239indices in a
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3240'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3241The value to insert must have the same type as the value identified
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3242by the indices.
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3243</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3244
3245<h5>Semantics:</h5>
3246
3247<p>
3248The result is an aggregate of the same type as <tt>val</tt>. Its
3249value is that of <tt>val</tt> except that the value at the position
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3250specified by the indices is that of <tt>elt</tt>.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3251</p>
3252
3253<h5>Example:</h5>
3254
3255<pre>
Dan Gohman52bb2db2008-06-23 15:26:37 +0000[diff] [blame]3256 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3257</pre>
3258</div>
3259
3260
3261<!-- ======================================================================= -->
3262<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3263 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3264</div>
3265
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3266<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3267
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3268<p>A key design point of an SSA-based representation is how it
3269represents memory. In LLVM, no memory locations are in SSA form, which
3270makes things very simple. This section describes how to read, write,
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3271allocate, and free memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3272
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3273</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3274
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3275<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3276<div class="doc_subsubsection">
3277 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3278</div>
3279
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3280<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3281
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3282<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3283
3284<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3285 &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]3286</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3287
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3288<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3289
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3290<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]3291heap and returns a pointer to it. The object is always allocated in the generic
3292address space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3293
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3294<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3295
3296<p>The '<tt>malloc</tt>' instruction allocates
3297<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswell6e4ca612004-02-24 16:13:56 +0000[diff] [blame]3298bytes of memory from the operating system and returns a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3299appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3300number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3301If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3302be aligned to at least that boundary. If not specified, or if zero, the target can
3303choose to align the allocation on any convenient boundary.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3304
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3305<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3306
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3307<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3308
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3309<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewycky02ff3082008-11-24 03:41:24 +0000[diff] [blame]3310a pointer is returned. The result of a zero byte allocation is undefined. The
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3311result is null if there is insufficient memory available.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3312
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3313<h5>Example:</h5>
3314
3315<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3316 %array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3317
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3318 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3319 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3320 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3321 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3322 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3323</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]3324
3325<p>Note that the code generator does not yet respect the
3326 alignment value.</p>
3327
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3328</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3329
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3330<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3331<div class="doc_subsubsection">
3332 <a name="i_free">'<tt>free</tt>' Instruction</a>
3333</div>
3334
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3335<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3336
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3337<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3338
3339<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3340 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3341</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3342
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3343<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3344
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3345<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]3346memory heap to be reallocated in the future.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3347
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3348<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3349
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3350<p>'<tt>value</tt>' shall be a pointer value that points to a value
3351that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
3352instruction.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3353
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3354<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3355
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3356<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattnere0db56d2008-04-19 22:41:32 +0000[diff] [blame]3357after this instruction executes. If the pointer is null, the operation
3358is a noop.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3359
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3360<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3361
3362<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3363 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3364 free [4 x i8]* %array
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3365</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3366</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3367
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3368<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3369<div class="doc_subsubsection">
3370 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3371</div>
3372
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3373<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3374
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3375<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3376
3377<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3378 &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]3379</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3380
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3381<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3382
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3383<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
3384currently executing function, to be automatically released when this function
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]3385returns to its caller. The object is always allocated in the generic address
3386space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3387
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3388<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3389
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3390<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3391bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3392appropriate type to the program. If "NumElements" is specified, it is the
3393number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3394If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3395to be aligned to at least that boundary. If not specified, or if zero, the target
3396can choose to align the allocation on any convenient boundary.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3397
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3398<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3399
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3400<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3401
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3402<p>Memory is allocated; a pointer is returned. The operation is undefiend if
3403there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3404memory is automatically released when the function returns. The '<tt>alloca</tt>'
3405instruction is commonly used to represent automatic variables that must
3406have an address available. When the function returns (either with the <tt><a
John Criswelldae2e932005-05-12 16:55:34 +0000[diff] [blame]3407 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]3408instructions), the memory is reclaimed. Allocating zero bytes
3409is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3410
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3411<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3412
3413<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3414 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
3415 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3416 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
3417 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3418</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3419</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3420
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3421<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3422<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3423Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3424<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3425<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]3426<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]3427<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3428<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3429<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3430<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]3431address from which to load. The pointer must point to a <a
Chris Lattnere53e5082004-06-03 22:57:15 +0000[diff] [blame]3432 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]3433marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3434the number or order of execution of this <tt>load</tt> with other
3435volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3436instructions. </p>
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3437<p>
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3438The optional constant "align" argument specifies the alignment of the operation
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3439(that is, the alignment of the memory address). A value of 0 or an
3440omitted "align" argument means that the operation has the preferential
3441alignment for the target. It is the responsibility of the code emitter
3442to ensure that the alignment information is correct. Overestimating
3443the alignment results in an undefined behavior. Underestimating the
3444alignment may produce less efficient code. An alignment of 1 is always
3445safe.
3446</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3447<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3448<p>The location of memory pointed to is loaded.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3449<h5>Examples:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3450<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3451 <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3452 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
3453 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3454</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3455</div>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3456<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3457<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3458Instruction</a> </div>
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]3459<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3460<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]3461<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
3462 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]3463</pre>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3464<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3465<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3466<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3467<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3468to 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]3469operand must be a pointer to the <a href="#t_firstclass">first class</a> type
3470of the '<tt>&lt;value&gt;</tt>'
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]3471operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3472optimizer is not allowed to modify the number or order of execution of
3473this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
3474 href="#i_store">store</a></tt> instructions.</p>
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3475<p>
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3476The optional constant "align" argument specifies the alignment of the operation
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3477(that is, the alignment of the memory address). A value of 0 or an
3478omitted "align" argument means that the operation has the preferential
3479alignment for the target. It is the responsibility of the code emitter
3480to ensure that the alignment information is correct. Overestimating
3481the alignment results in an undefined behavior. Underestimating the
3482alignment may produce less efficient code. An alignment of 1 is always
3483safe.
3484</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3485<h5>Semantics:</h5>
3486<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
3487at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3488<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3489<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]3490 store i32 3, i32* %ptr <i>; yields {void}</i>
3491 %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]3492</pre>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3493</div>
3494
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3495<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3496<div class="doc_subsubsection">
3497 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3498</div>
3499
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3500<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3501<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3502<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3503 &lt;result&gt; = getelementptr &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3504</pre>
3505
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3506<h5>Overview:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3507
3508<p>
3509The '<tt>getelementptr</tt>' instruction is used to get the address of a
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3510subelement of an aggregate data structure. It performs address calculation only
3511and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3512
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3513<h5>Arguments:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3514
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3515<p>The first argument is always a pointer, and forms the basis of the
3516calculation. The remaining arguments are indices, that indicate which of the
3517elements of the aggregate object are indexed. The interpretation of each index
3518is dependent on the type being indexed into. The first index always indexes the
3519pointer value given as the first argument, the second index indexes a value of
3520the type pointed to (not necessarily the value directly pointed to, since the
3521first index can be non-zero), etc. The first type indexed into must be a pointer
3522value, subsequent types can be arrays, vectors and structs. Note that subsequent
3523types being indexed into can never be pointers, since that would require loading
3524the pointer before continuing calculation.</p>
3525
3526<p>The type of each index argument depends on the type it is indexing into.
3527When indexing into a (packed) structure, only <tt>i32</tt> integer
3528<b>constants</b> are allowed. When indexing into an array, pointer or vector,
3529only integers of 32 or 64 bits are allowed (also non-constants). 32-bit values
3530will be sign extended to 64-bits if required.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3531
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3532<p>For example, let's consider a C code fragment and how it gets
3533compiled to LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3534
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3535<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3536<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3537struct RT {
3538 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3539 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3540 char C;
3541};
3542struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3543 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3544 double Y;
3545 struct RT Z;
3546};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3547
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3548int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3549 return &amp;s[1].Z.B[5][13];
3550}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3551</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3552</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3553
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3554<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3555
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3556<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3557<pre>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]3558%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
3559%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3560
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3561define i32* %foo(%ST* %s) {
3562entry:
3563 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3564 ret i32* %reg
3565}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3566</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3567</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3568
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3569<h5>Semantics:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3570
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3571<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]3572type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3573}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3574the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3575i8 }</tt>' type, another structure. The third index indexes into the second
3576element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3577array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3578'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
3579to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3580
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3581<p>Note that it is perfectly legal to index partially through a
3582structure, returning a pointer to an inner element. Because of this,
3583the LLVM code for the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3584
3585<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3586 define i32* %foo(%ST* %s) {
3587 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3588 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3589 %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]3590 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3591 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
3592 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3593 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3594</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3595
3596<p>Note that it is undefined to access an array out of bounds: array and
3597pointer indexes must always be within the defined bounds of the array type.
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]3598The one exception for this rule is zero length arrays. These arrays are
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3599defined to be accessible as variable length arrays, which requires access
3600beyond the zero'th element.</p>
3601
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3602<p>The getelementptr instruction is often confusing. For some more insight
3603into how it works, see <a href="GetElementPtr.html">the getelementptr
3604FAQ</a>.</p>
3605
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3606<h5>Example:</h5>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3607
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3608<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3609 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3610 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
3611 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3612 %vptr = getelementptr {i32, &lt;2 x i8&gt;}* %svptr, i64 0, i32 1, i32 1
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3613 <i>; yields i8*:eptr</i>
3614 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3615</pre>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3616</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3617
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3618<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3619<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3620</div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3621<div class="doc_text">
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3622<p>The instructions in this category are the conversion instructions (casting)
3623which all take a single operand and a type. They perform various bit conversions
3624on the operand.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3625</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3626
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3627<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3628<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3629 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
3630</div>
3631<div class="doc_text">
3632
3633<h5>Syntax:</h5>
3634<pre>
3635 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3636</pre>
3637
3638<h5>Overview:</h5>
3639<p>
3640The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
3641</p>
3642
3643<h5>Arguments:</h5>
3644<p>
3645The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
3646be 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]3647and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3648type. The bit size of <tt>value</tt> must be larger than the bit size of
3649<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3650
3651<h5>Semantics:</h5>
3652<p>
3653The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3654and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
3655larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
3656It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3657
3658<h5>Example:</h5>
3659<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3660 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3661 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
3662 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3663</pre>
3664</div>
3665
3666<!-- _______________________________________________________________________ -->
3667<div class="doc_subsubsection">
3668 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
3669</div>
3670<div class="doc_text">
3671
3672<h5>Syntax:</h5>
3673<pre>
3674 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3675</pre>
3676
3677<h5>Overview:</h5>
3678<p>The '<tt>zext</tt>' instruction zero extends its operand to type
3679<tt>ty2</tt>.</p>
3680
3681
3682<h5>Arguments:</h5>
3683<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]3684<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3685also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3686<tt>value</tt> must be smaller than the bit size of the destination type,
3687<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3688
3689<h5>Semantics:</h5>
3690<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]3691bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3692
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]3693<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]3694
3695<h5>Example:</h5>
3696<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3697 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3698 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3699</pre>
3700</div>
3701
3702<!-- _______________________________________________________________________ -->
3703<div class="doc_subsubsection">
3704 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3705</div>
3706<div class="doc_text">
3707
3708<h5>Syntax:</h5>
3709<pre>
3710 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3711</pre>
3712
3713<h5>Overview:</h5>
3714<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3715
3716<h5>Arguments:</h5>
3717<p>
3718The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3719<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3720also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3721<tt>value</tt> must be smaller than the bit size of the destination type,
3722<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3723
3724<h5>Semantics:</h5>
3725<p>
3726The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3727bit (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]3728the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3729
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3730<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]3731
3732<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3733<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3734 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3735 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3736</pre>
3737</div>
3738
3739<!-- _______________________________________________________________________ -->
3740<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3741 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3742</div>
3743
3744<div class="doc_text">
3745
3746<h5>Syntax:</h5>
3747
3748<pre>
3749 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3750</pre>
3751
3752<h5>Overview:</h5>
3753<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3754<tt>ty2</tt>.</p>
3755
3756
3757<h5>Arguments:</h5>
3758<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3759 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3760cast it to. The size of <tt>value</tt> must be larger than the size of
3761<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3762<i>no-op cast</i>.</p>
3763
3764<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3765<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3766<a href="#t_floating">floating point</a> type to a smaller
3767<a href="#t_floating">floating point</a> type. If the value cannot fit within
3768the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3769
3770<h5>Example:</h5>
3771<pre>
3772 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3773 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3774</pre>
3775</div>
3776
3777<!-- _______________________________________________________________________ -->
3778<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3779 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3780</div>
3781<div class="doc_text">
3782
3783<h5>Syntax:</h5>
3784<pre>
3785 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3786</pre>
3787
3788<h5>Overview:</h5>
3789<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3790floating point value.</p>
3791
3792<h5>Arguments:</h5>
3793<p>The '<tt>fpext</tt>' instruction takes a
3794<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3795and a <a href="#t_floating">floating point</a> type to cast it to. The source
3796type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3797
3798<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3799<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3800<a href="#t_floating">floating point</a> type to a larger
3801<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3802used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3803<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]3804
3805<h5>Example:</h5>
3806<pre>
3807 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3808 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3809</pre>
3810</div>
3811
3812<!-- _______________________________________________________________________ -->
3813<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]3814 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3815</div>
3816<div class="doc_text">
3817
3818<h5>Syntax:</h5>
3819<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3820 &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]3821</pre>
3822
3823<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3824<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3825unsigned integer equivalent of type <tt>ty2</tt>.
3826</p>
3827
3828<h5>Arguments:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3829<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]3830scalar or vector <a href="#t_floating">floating point</a> value, and a type
3831to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3832type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3833vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3834
3835<h5>Semantics:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3836<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3837<a href="#t_floating">floating point</a> operand into the nearest (rounding
3838towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3839the results are undefined.</p>
3840
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3841<h5>Example:</h5>
3842<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3843 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3844 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3845 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3846</pre>
3847</div>
3848
3849<!-- _______________________________________________________________________ -->
3850<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3851 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3852</div>
3853<div class="doc_text">
3854
3855<h5>Syntax:</h5>
3856<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3857 &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]3858</pre>
3859
3860<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3861<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3862<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]3863</p>
3864
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3865<h5>Arguments:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3866<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]3867scalar or vector <a href="#t_floating">floating point</a> value, and a type
3868to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3869type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3870vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3871
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3872<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3873<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3874<a href="#t_floating">floating point</a> operand into the nearest (rounding
3875towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3876the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3877
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3878<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3879<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3880 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3881 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3882 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3883</pre>
3884</div>
3885
3886<!-- _______________________________________________________________________ -->
3887<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3888 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3889</div>
3890<div class="doc_text">
3891
3892<h5>Syntax:</h5>
3893<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3894 &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]3895</pre>
3896
3897<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3898<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3899integer and converts that value to the <tt>ty2</tt> type.</p>
3900
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3901<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3902<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3903scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3904to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3905type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3906floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3907
3908<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3909<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3910integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3911the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3912
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3913<h5>Example:</h5>
3914<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3915 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3916 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3917</pre>
3918</div>
3919
3920<!-- _______________________________________________________________________ -->
3921<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3922 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3923</div>
3924<div class="doc_text">
3925
3926<h5>Syntax:</h5>
3927<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3928 &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]3929</pre>
3930
3931<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3932<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3933integer and converts that value to the <tt>ty2</tt> type.</p>
3934
3935<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3936<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3937scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3938to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3939type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3940floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3941
3942<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3943<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3944integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3945the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3946
3947<h5>Example:</h5>
3948<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3949 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3950 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3951</pre>
3952</div>
3953
3954<!-- _______________________________________________________________________ -->
3955<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3956 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3957</div>
3958<div class="doc_text">
3959
3960<h5>Syntax:</h5>
3961<pre>
3962 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3963</pre>
3964
3965<h5>Overview:</h5>
3966<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3967the integer type <tt>ty2</tt>.</p>
3968
3969<h5>Arguments:</h5>
3970<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3971must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3972<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3973
3974<h5>Semantics:</h5>
3975<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3976<tt>ty2</tt> by interpreting the pointer value as an integer and either
3977truncating or zero extending that value to the size of the integer type. If
3978<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3979<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]3980are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3981change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3982
3983<h5>Example:</h5>
3984<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3985 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3986 %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]3987</pre>
3988</div>
3989
3990<!-- _______________________________________________________________________ -->
3991<div class="doc_subsubsection">
3992 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3993</div>
3994<div class="doc_text">
3995
3996<h5>Syntax:</h5>
3997<pre>
3998 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3999</pre>
4000
4001<h5>Overview:</h5>
4002<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
4003a pointer type, <tt>ty2</tt>.</p>
4004
4005<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4006<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4007value to cast, and a type to cast it to, which must be a
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4008<a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4009
4010<h5>Semantics:</h5>
4011<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
4012<tt>ty2</tt> by applying either a zero extension or a truncation depending on
4013the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
4014size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
4015the size of a pointer then a zero extension is done. If they are the same size,
4016nothing is done (<i>no-op cast</i>).</p>
4017
4018<h5>Example:</h5>
4019<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4020 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
4021 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
4022 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4023</pre>
4024</div>
4025
4026<!-- _______________________________________________________________________ -->
4027<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4028 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4029</div>
4030<div class="doc_text">
4031
4032<h5>Syntax:</h5>
4033<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4034 &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]4035</pre>
4036
4037<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4038
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4039<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4040<tt>ty2</tt> without changing any bits.</p>
4041
4042<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4043
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4044<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Dan Gohman500233a2008-09-08 16:45:59 +0000[diff] [blame]4045a non-aggregate first class value, and a type to cast it to, which must also be
4046a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
4047<tt>value</tt>
Reid Spencer19b569f2007-01-09 20:08:58 +0000[diff] [blame]4048and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4049type is a pointer, the destination type must also be a pointer. This
4050instruction supports bitwise conversion of vectors to integers and to vectors
4051of other types (as long as they have the same size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4052
4053<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4054<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4055<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
4056this conversion. The conversion is done as if the <tt>value</tt> had been
4057stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
4058converted to other pointer types with this instruction. To convert pointers to
4059other types, use the <a href="#i_inttoptr">inttoptr</a> or
4060<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4061
4062<h5>Example:</h5>
4063<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4064 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4065 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4066 %Z = bitcast &lt;2 x int&gt; %V to i64; <i>; yields i64: %V</i>
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]4067</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4068</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4069
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4070<!-- ======================================================================= -->
4071<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
4072<div class="doc_text">
4073<p>The instructions in this category are the "miscellaneous"
4074instructions, which defy better classification.</p>
4075</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4076
4077<!-- _______________________________________________________________________ -->
4078<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4079</div>
4080<div class="doc_text">
4081<h5>Syntax:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4082<pre> &lt;result&gt; = icmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt;}:result</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4083</pre>
4084<h5>Overview:</h5>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4085<p>The '<tt>icmp</tt>' instruction returns a boolean value or
4086a vector of boolean values based on comparison
4087of its two integer, integer vector, or pointer operands.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4088<h5>Arguments:</h5>
4089<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4090the condition code indicating the kind of comparison to perform. It is not
4091a value, just a keyword. The possible condition code are:
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4092</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4093<ol>
4094 <li><tt>eq</tt>: equal</li>
4095 <li><tt>ne</tt>: not equal </li>
4096 <li><tt>ugt</tt>: unsigned greater than</li>
4097 <li><tt>uge</tt>: unsigned greater or equal</li>
4098 <li><tt>ult</tt>: unsigned less than</li>
4099 <li><tt>ule</tt>: unsigned less or equal</li>
4100 <li><tt>sgt</tt>: signed greater than</li>
4101 <li><tt>sge</tt>: signed greater or equal</li>
4102 <li><tt>slt</tt>: signed less than</li>
4103 <li><tt>sle</tt>: signed less or equal</li>
4104</ol>
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]4105<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4106<a href="#t_pointer">pointer</a>
4107or integer <a href="#t_vector">vector</a> typed.
4108They must also be identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4109<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4110<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]4111the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4112yields either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt> result, as follows:
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4113</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4114<ol>
4115 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
4116 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
4117 </li>
4118 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4119 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4120 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4121 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4122 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4123 <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]4124 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4125 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4126 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4127 <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]4128 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4129 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4130 <li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4131 <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]4132 <li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4133 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4134 <li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4135 <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]4136</ol>
4137<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4138values are compared as if they were integers.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4139<p>If the operands are integer vectors, then they are compared
4140element by element. The result is an <tt>i1</tt> vector with
4141the same number of elements as the values being compared.
4142Otherwise, the result is an <tt>i1</tt>.
4143</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4144
4145<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4146<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
4147 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4148 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4149 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4150 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4151 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4152</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4153
4154<p>Note that the code generator does not yet support vector types with
4155 the <tt>icmp</tt> instruction.</p>
4156
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4157</div>
4158
4159<!-- _______________________________________________________________________ -->
4160<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4161</div>
4162<div class="doc_text">
4163<h5>Syntax:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4164<pre> &lt;result&gt; = fcmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt;}:result</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4165</pre>
4166<h5>Overview:</h5>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4167<p>The '<tt>fcmp</tt>' instruction returns a boolean value
4168or vector of boolean values based on comparison
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4169of its operands.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4170<p>
4171If the operands are floating point scalars, then the result
4172type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
4173</p>
4174<p>If the operands are floating point vectors, then the result type
4175is a vector of boolean with the same number of elements as the
4176operands being compared.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4177<h5>Arguments:</h5>
4178<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4179the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4180a value, just a keyword. The possible condition code are:</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4181<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4182 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4183 <li><tt>oeq</tt>: ordered and equal</li>
4184 <li><tt>ogt</tt>: ordered and greater than </li>
4185 <li><tt>oge</tt>: ordered and greater than or equal</li>
4186 <li><tt>olt</tt>: ordered and less than </li>
4187 <li><tt>ole</tt>: ordered and less than or equal</li>
4188 <li><tt>one</tt>: ordered and not equal</li>
4189 <li><tt>ord</tt>: ordered (no nans)</li>
4190 <li><tt>ueq</tt>: unordered or equal</li>
4191 <li><tt>ugt</tt>: unordered or greater than </li>
4192 <li><tt>uge</tt>: unordered or greater than or equal</li>
4193 <li><tt>ult</tt>: unordered or less than </li>
4194 <li><tt>ule</tt>: unordered or less than or equal</li>
4195 <li><tt>une</tt>: unordered or not equal</li>
4196 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4197 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4198</ol>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4199<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer93a49852006-12-06 07:08:07 +0000[diff] [blame]4200<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4201<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
4202either a <a href="#t_floating">floating point</a> type
4203or a <a href="#t_vector">vector</a> of floating point type.
4204They must have identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4205<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4206<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4207according to the condition code given as <tt>cond</tt>.
4208If the operands are vectors, then the vectors are compared
4209element by element.
4210Each comparison performed
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4211always yields an <a href="#t_primitive">i1</a> result, as follows:</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4212<ol>
4213 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4214 <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]4215 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4216 <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]4217 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4218 <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]4219 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4220 <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]4221 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4222 <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]4223 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4224 <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]4225 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4226 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
4227 <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]4228 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4229 <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]4230 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4231 <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]4232 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4233 <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]4234 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4235 <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]4236 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4237 <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]4238 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4239 <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]4240 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4241</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4242
4243<h5>Example:</h5>
4244<pre> &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4245 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4246 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4247 &lt;result&gt; = fcmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4248</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4249
4250<p>Note that the code generator does not yet support vector types with
4251 the <tt>fcmp</tt> instruction.</p>
4252
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4253</div>
4254
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4255<!-- _______________________________________________________________________ -->
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4256<div class="doc_subsubsection">
4257 <a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
4258</div>
4259<div class="doc_text">
4260<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4261<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]4262</pre>
4263<h5>Overview:</h5>
4264<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
4265element-wise comparison of its two integer vector operands.</p>
4266<h5>Arguments:</h5>
4267<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
4268the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4269a value, just a keyword. The possible condition code are:</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4270<ol>
4271 <li><tt>eq</tt>: equal</li>
4272 <li><tt>ne</tt>: not equal </li>
4273 <li><tt>ugt</tt>: unsigned greater than</li>
4274 <li><tt>uge</tt>: unsigned greater or equal</li>
4275 <li><tt>ult</tt>: unsigned less than</li>
4276 <li><tt>ule</tt>: unsigned less or equal</li>
4277 <li><tt>sgt</tt>: signed greater than</li>
4278 <li><tt>sge</tt>: signed greater or equal</li>
4279 <li><tt>slt</tt>: signed less than</li>
4280 <li><tt>sle</tt>: signed less or equal</li>
4281</ol>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4282<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4283<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
4284<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4285<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4286according to the condition code given as <tt>cond</tt>. The comparison yields a
4287<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
4288identical type as the values being compared. The most significant bit in each
4289element is 1 if the element-wise comparison evaluates to true, and is 0
4290otherwise. All other bits of the result are undefined. The condition codes
4291are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4292instruction</a>.</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4293
4294<h5>Example:</h5>
4295<pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4296 &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>
4297 &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]4298</pre>
4299</div>
4300
4301<!-- _______________________________________________________________________ -->
4302<div class="doc_subsubsection">
4303 <a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
4304</div>
4305<div class="doc_text">
4306<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4307<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]4308<h5>Overview:</h5>
4309<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
4310element-wise comparison of its two floating point vector operands. The output
4311elements have the same width as the input elements.</p>
4312<h5>Arguments:</h5>
4313<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
4314the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4315a value, just a keyword. The possible condition code are:</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4316<ol>
4317 <li><tt>false</tt>: no comparison, always returns false</li>
4318 <li><tt>oeq</tt>: ordered and equal</li>
4319 <li><tt>ogt</tt>: ordered and greater than </li>
4320 <li><tt>oge</tt>: ordered and greater than or equal</li>
4321 <li><tt>olt</tt>: ordered and less than </li>
4322 <li><tt>ole</tt>: ordered and less than or equal</li>
4323 <li><tt>one</tt>: ordered and not equal</li>
4324 <li><tt>ord</tt>: ordered (no nans)</li>
4325 <li><tt>ueq</tt>: unordered or equal</li>
4326 <li><tt>ugt</tt>: unordered or greater than </li>
4327 <li><tt>uge</tt>: unordered or greater than or equal</li>
4328 <li><tt>ult</tt>: unordered or less than </li>
4329 <li><tt>ule</tt>: unordered or less than or equal</li>
4330 <li><tt>une</tt>: unordered or not equal</li>
4331 <li><tt>uno</tt>: unordered (either nans)</li>
4332 <li><tt>true</tt>: no comparison, always returns true</li>
4333</ol>
4334<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
4335<a href="#t_floating">floating point</a> typed. They must also be identical
4336types.</p>
4337<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4338<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4339according to the condition code given as <tt>cond</tt>. The comparison yields a
4340<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
4341an identical number of elements as the values being compared, and each element
4342having identical with to the width of the floating point elements. The most
4343significant bit in each element is 1 if the element-wise comparison evaluates to
4344true, and is 0 otherwise. All other bits of the result are undefined. The
4345condition codes are evaluated identically to the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4346<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4347
4348<h5>Example:</h5>
4349<pre>
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]4350 <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0, i32 -1 &gt;</i>
4351 &lt;result&gt; = vfcmp oeq &lt;2 x float&gt; &lt; float 4, float 0 &gt;, &lt; float 5, float 0 &gt;
4352
4353 <i>; yields: result=&lt;2 x i64&gt; &lt; i64 -1, i64 0 &gt;</i>
4354 &lt;result&gt; = vfcmp ult &lt;2 x double&gt; &lt; double 1, double 2 &gt;, &lt; double 2, double 2&gt;
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4355</pre>
4356</div>
4357
4358<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4359<div class="doc_subsubsection">
4360 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4361</div>
4362
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4363<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4364
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4365<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4366
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4367<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
4368<h5>Overview:</h5>
4369<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
4370the SSA graph representing the function.</p>
4371<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4372
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4373<p>The type of the incoming values is specified with the first type
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4374field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
4375as arguments, with one pair for each predecessor basic block of the
4376current block. Only values of <a href="#t_firstclass">first class</a>
4377type may be used as the value arguments to the PHI node. Only labels
4378may be used as the label arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4379
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4380<p>There must be no non-phi instructions between the start of a basic
4381block and the PHI instructions: i.e. PHI instructions must be first in
4382a basic block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4383
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4384<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4385
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4386<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
4387specified by the pair corresponding to the predecessor basic block that executed
4388just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4389
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4390<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4391<pre>
4392Loop: ; Infinite loop that counts from 0 on up...
4393 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4394 %nextindvar = add i32 %indvar, 1
4395 br label %Loop
4396</pre>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4397</div>
4398
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4399<!-- _______________________________________________________________________ -->
4400<div class="doc_subsubsection">
4401 <a name="i_select">'<tt>select</tt>' Instruction</a>
4402</div>
4403
4404<div class="doc_text">
4405
4406<h5>Syntax:</h5>
4407
4408<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4409 &lt;result&gt; = select <i>selty</i> &lt;cond&gt;, &lt;ty&gt; &lt;val1&gt;, &lt;ty&gt; &lt;val2&gt; <i>; yields ty</i>
4410
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4411 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4412</pre>
4413
4414<h5>Overview:</h5>
4415
4416<p>
4417The '<tt>select</tt>' instruction is used to choose one value based on a
4418condition, without branching.
4419</p>
4420
4421
4422<h5>Arguments:</h5>
4423
4424<p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4425The '<tt>select</tt>' instruction requires an 'i1' value or
4426a vector of 'i1' values indicating the
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4427condition, and two values of the same <a href="#t_firstclass">first class</a>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4428type. If the val1/val2 are vectors and
4429the condition is a scalar, then entire vectors are selected, not
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4430individual elements.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4431</p>
4432
4433<h5>Semantics:</h5>
4434
4435<p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4436If the condition is an i1 and it evaluates to 1, the instruction returns the first
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4437value argument; otherwise, it returns the second value argument.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4438</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4439<p>
4440If the condition is a vector of i1, then the value arguments must
4441be vectors of the same size, and the selection is done element
4442by element.
4443</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4444
4445<h5>Example:</h5>
4446
4447<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4448 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4449</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4450
4451<p>Note that the code generator does not yet support conditions
4452 with vector type.</p>
4453
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4454</div>
4455
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]4456
4457<!-- _______________________________________________________________________ -->
4458<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4459 <a name="i_call">'<tt>call</tt>' Instruction</a>
4460</div>
4461
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4462<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4463
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4464<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4465<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]4466 &lt;result&gt; = [tail] call [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] &lt;ty&gt; [&lt;fnty&gt;*] &lt;fnptrval&gt;(&lt;function args&gt;) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4467</pre>
4468
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4469<h5>Overview:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4470
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4471<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4472
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4473<h5>Arguments:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4474
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4475<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4476
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4477<ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4478 <li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4479 <p>The optional "tail" marker indicates whether the callee function accesses
4480 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4481 function call is eligible for tail call optimization. Note that calls may
4482 be marked "tail" even if they do not occur before a <a
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4483 href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4484 </li>
4485 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4486 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4487 convention</a> the call should use. If none is specified, the call defaults
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4488 to using C calling conventions.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4489 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4490
4491 <li>
4492 <p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4493 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
4494 and '<tt>inreg</tt>' attributes are valid here.</p>
4495 </li>
4496
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4497 <li>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4498 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
4499 the type of the return value. Functions that return no value are marked
4500 <tt><a href="#t_void">void</a></tt>.</p>
4501 </li>
4502 <li>
4503 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
4504 value being invoked. The argument types must match the types implied by
4505 this signature. This type can be omitted if the function is not varargs
4506 and if the function type does not return a pointer to a function.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4507 </li>
4508 <li>
4509 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4510 be invoked. In most cases, this is a direct function invocation, but
4511 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4512 to function value.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4513 </li>
4514 <li>
4515 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencera7e302a2005-05-01 22:22:57 +0000[diff] [blame]4516 function signature argument types. All arguments must be of
4517 <a href="#t_firstclass">first class</a> type. If the function signature
4518 indicates the function accepts a variable number of arguments, the extra
4519 arguments can be specified.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4520 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4521 <li>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]4522 <p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4523 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
4524 '<tt>readnone</tt>' attributes are valid here.</p>
4525 </li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4526</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4527
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4528<h5>Semantics:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4529
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4530<p>The '<tt>call</tt>' instruction is used to cause control flow to
4531transfer to a specified function, with its incoming arguments bound to
4532the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
4533instruction in the called function, control flow continues with the
4534instruction after the function call, and the return value of the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4535function is bound to the result argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4536
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4537<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4538
4539<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4540 %retval = call i32 @test(i32 %argc)
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]4541 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4542 %X = tail call i32 @foo() <i>; yields i32</i>
4543 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4544 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]4545
4546 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4547 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]4548 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
4549 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]4550 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]4551 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4552</pre>
4553
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4554</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4555
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4556<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4557<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]4558 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4559</div>
4560
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4561<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4562
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4563<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4564
4565<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4566 &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]4567</pre>
4568
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4569<h5>Overview:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4570
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4571<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4572the "variable argument" area of a function call. It is used to implement the
4573<tt>va_arg</tt> macro in C.</p>
4574
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4575<h5>Arguments:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4576
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4577<p>This instruction takes a <tt>va_list*</tt> value and the type of
4578the argument. It returns a value of the specified argument type and
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4579increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4580actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4581
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4582<h5>Semantics:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4583
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4584<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
4585type from the specified <tt>va_list</tt> and causes the
4586<tt>va_list</tt> to point to the next argument. For more information,
4587see the variable argument handling <a href="#int_varargs">Intrinsic
4588Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4589
4590<p>It is legal for this instruction to be called in a function which does not
4591take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4592function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4593
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4594<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4595href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4596argument.</p>
4597
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4598<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4599
4600<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4601
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]4602<p>Note that the code generator does not yet fully support va_arg
4603 on many targets. Also, it does not currently support va_arg with
4604 aggregate types on any target.</p>
4605
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4606</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4607
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4608<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4609<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4610<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4611
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4612<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4613
4614<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4615well known names and semantics and are required to follow certain restrictions.
4616Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4617language that does not require changing all of the transformations in LLVM when
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]4618adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4619
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4620<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4621prefix is reserved in LLVM for intrinsic names; thus, function names may not
4622begin with this prefix. Intrinsic functions must always be external functions:
4623you cannot define the body of intrinsic functions. Intrinsic functions may
4624only be used in call or invoke instructions: it is illegal to take the address
4625of an intrinsic function. Additionally, because intrinsic functions are part
4626of the LLVM language, it is required if any are added that they be documented
4627here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4628
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4629<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
4630a family of functions that perform the same operation but on different data
4631types. Because LLVM can represent over 8 million different integer types,
4632overloading is used commonly to allow an intrinsic function to operate on any
4633integer type. One or more of the argument types or the result type can be
4634overloaded to accept any integer type. Argument types may also be defined as
4635exactly matching a previous argument's type or the result type. This allows an
4636intrinsic function which accepts multiple arguments, but needs all of them to
4637be of the same type, to only be overloaded with respect to a single argument or
4638the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4639
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4640<p>Overloaded intrinsics will have the names of its overloaded argument types
4641encoded into its function name, each preceded by a period. Only those types
4642which are overloaded result in a name suffix. Arguments whose type is matched
4643against another type do not. For example, the <tt>llvm.ctpop</tt> function can
4644take an integer of any width and returns an integer of exactly the same integer
4645width. This leads to a family of functions such as
4646<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
4647Only one type, the return type, is overloaded, and only one type suffix is
4648required. Because the argument's type is matched against the return type, it
4649does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4650
4651<p>To learn how to add an intrinsic function, please see the
4652<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4653</p>
4654
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4655</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4656
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4657<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4658<div class="doc_subsection">
4659 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
4660</div>
4661
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4662<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4663
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4664<p>Variable argument support is defined in LLVM with the <a
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]4665 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4666intrinsic functions. These functions are related to the similarly
4667named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4668
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4669<p>All of these functions operate on arguments that use a
4670target-specific value type "<tt>va_list</tt>". The LLVM assembly
4671language reference manual does not define what this type is, so all
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4672transformations should be prepared to handle these functions regardless of
4673the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4674
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]4675<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]4676instruction and the variable argument handling intrinsic functions are
4677used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4678
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4679<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4680<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4681define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4682 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4683 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4684 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4685 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4686
4687 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4688 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4689
4690 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4691 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4692 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4693 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4694 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4695
4696 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4697 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4698 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4699}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4700
4701declare void @llvm.va_start(i8*)
4702declare void @llvm.va_copy(i8*, i8*)
4703declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4704</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4705</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4706
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4707</div>
4708
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4709<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4710<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4711 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4712</div>
4713
4714
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4715<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4716<h5>Syntax:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4717<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4718<h5>Overview:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4719<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4720<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
4721href="#i_va_arg">va_arg</a></tt>.</p>
4722
4723<h5>Arguments:</h5>
4724
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4725<p>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4726
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4727<h5>Semantics:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4728
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4729<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4730macro available in C. In a target-dependent way, it initializes the
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4731<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]4732<tt>va_arg</tt> will produce the first variable argument passed to the function.
4733Unlike 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]4734last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4735
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4736</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4737
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4738<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4739<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4740 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4741</div>
4742
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4743<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4744<h5>Syntax:</h5>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4745<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4746<h5>Overview:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4747
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4748<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4749which 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]4750or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4751
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4752<h5>Arguments:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4753
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4754<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]4755
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4756<h5>Semantics:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4757
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4758<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]4759macro available in C. In a target-dependent way, it destroys the
4760<tt>va_list</tt> element to which the argument points. Calls to <a
4761href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
4762<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
4763<tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4764
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4765</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4766
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4767<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4768<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4769 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4770</div>
4771
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4772<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4773
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4774<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4775
4776<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4777 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4778</pre>
4779
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4780<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4781
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4782<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
4783from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4784
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4785<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4786
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4787<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]4788The 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]4789
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4790
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4791<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4792
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4793<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
4794macro available in C. In a target-dependent way, it copies the source
4795<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
4796intrinsic is necessary because the <tt><a href="#int_va_start">
4797llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
4798example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4799
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4800</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4801
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4802<!-- ======================================================================= -->
4803<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4804 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
4805</div>
4806
4807<div class="doc_text">
4808
4809<p>
4810LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]4811Collection</a> (GC) requires the implementation and generation of these
4812intrinsics.
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4813These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4814stack</a>, as well as garbage collector implementations that require <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4815href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4816Front-ends for type-safe garbage collected languages should generate these
4817intrinsics to make use of the LLVM garbage collectors. For more details, see <a
4818href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
4819</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]4820
4821<p>The garbage collection intrinsics only operate on objects in the generic
4822 address space (address space zero).</p>
4823
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4824</div>
4825
4826<!-- _______________________________________________________________________ -->
4827<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4828 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4829</div>
4830
4831<div class="doc_text">
4832
4833<h5>Syntax:</h5>
4834
4835<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4836 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4837</pre>
4838
4839<h5>Overview:</h5>
4840
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]4841<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]4842the code generator, and allows some metadata to be associated with it.</p>
4843
4844<h5>Arguments:</h5>
4845
4846<p>The first argument specifies the address of a stack object that contains the
4847root pointer. The second pointer (which must be either a constant or a global
4848value address) contains the meta-data to be associated with the root.</p>
4849
4850<h5>Semantics:</h5>
4851
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]4852<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]4853location. At compile-time, the code generator generates information to allow
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4854the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
4855intrinsic may only be used in a function which <a href="#gc">specifies a GC
4856algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4857
4858</div>
4859
4860
4861<!-- _______________________________________________________________________ -->
4862<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4863 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4864</div>
4865
4866<div class="doc_text">
4867
4868<h5>Syntax:</h5>
4869
4870<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4871 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4872</pre>
4873
4874<h5>Overview:</h5>
4875
4876<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4877locations, allowing garbage collector implementations that require read
4878barriers.</p>
4879
4880<h5>Arguments:</h5>
4881
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4882<p>The second argument is the address to read from, which should be an address
4883allocated from the garbage collector. The first object is a pointer to the
4884start of the referenced object, if needed by the language runtime (otherwise
4885null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4886
4887<h5>Semantics:</h5>
4888
4889<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4890instruction, but may be replaced with substantially more complex code by the
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4891garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
4892may only be used in a function which <a href="#gc">specifies a GC
4893algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4894
4895</div>
4896
4897
4898<!-- _______________________________________________________________________ -->
4899<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4900 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4901</div>
4902
4903<div class="doc_text">
4904
4905<h5>Syntax:</h5>
4906
4907<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4908 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4909</pre>
4910
4911<h5>Overview:</h5>
4912
4913<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4914locations, allowing garbage collector implementations that require write
4915barriers (such as generational or reference counting collectors).</p>
4916
4917<h5>Arguments:</h5>
4918
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4919<p>The first argument is the reference to store, the second is the start of the
4920object to store it to, and the third is the address of the field of Obj to
4921store to. If the runtime does not require a pointer to the object, Obj may be
4922null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4923
4924<h5>Semantics:</h5>
4925
4926<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4927instruction, but may be replaced with substantially more complex code by the
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4928garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
4929may only be used in a function which <a href="#gc">specifies a GC
4930algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4931
4932</div>
4933
4934
4935
4936<!-- ======================================================================= -->
4937<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4938 <a name="int_codegen">Code Generator Intrinsics</a>
4939</div>
4940
4941<div class="doc_text">
4942<p>
4943These intrinsics are provided by LLVM to expose special features that may only
4944be implemented with code generator support.
4945</p>
4946
4947</div>
4948
4949<!-- _______________________________________________________________________ -->
4950<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4951 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4952</div>
4953
4954<div class="doc_text">
4955
4956<h5>Syntax:</h5>
4957<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4958 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4959</pre>
4960
4961<h5>Overview:</h5>
4962
4963<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4964The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4965target-specific value indicating the return address of the current function
4966or one of its callers.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4967</p>
4968
4969<h5>Arguments:</h5>
4970
4971<p>
4972The argument to this intrinsic indicates which function to return the address
4973for. Zero indicates the calling function, one indicates its caller, etc. The
4974argument is <b>required</b> to be a constant integer value.
4975</p>
4976
4977<h5>Semantics:</h5>
4978
4979<p>
4980The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4981the return address of the specified call frame, or zero if it cannot be
4982identified. The value returned by this intrinsic is likely to be incorrect or 0
4983for arguments other than zero, so it should only be used for debugging purposes.
4984</p>
4985
4986<p>
4987Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4988aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4989source-language caller.
4990</p>
4991</div>
4992
4993
4994<!-- _______________________________________________________________________ -->
4995<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4996 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4997</div>
4998
4999<div class="doc_text">
5000
5001<h5>Syntax:</h5>
5002<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5003 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5004</pre>
5005
5006<h5>Overview:</h5>
5007
5008<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]5009The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5010target-specific frame pointer value for the specified stack frame.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5011</p>
5012
5013<h5>Arguments:</h5>
5014
5015<p>
5016The argument to this intrinsic indicates which function to return the frame
5017pointer for. Zero indicates the calling function, one indicates its caller,
5018etc. The argument is <b>required</b> to be a constant integer value.
5019</p>
5020
5021<h5>Semantics:</h5>
5022
5023<p>
5024The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
5025the frame address of the specified call frame, or zero if it cannot be
5026identified. The value returned by this intrinsic is likely to be incorrect or 0
5027for arguments other than zero, so it should only be used for debugging purposes.
5028</p>
5029
5030<p>
5031Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]5032aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5033source-language caller.
5034</p>
5035</div>
5036
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5037<!-- _______________________________________________________________________ -->
5038<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5039 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5040</div>
5041
5042<div class="doc_text">
5043
5044<h5>Syntax:</h5>
5045<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5046 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5047</pre>
5048
5049<h5>Overview:</h5>
5050
5051<p>
5052The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5053the function stack, for use with <a href="#int_stackrestore">
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5054<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
5055features like scoped automatic variable sized arrays in C99.
5056</p>
5057
5058<h5>Semantics:</h5>
5059
5060<p>
5061This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5062href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5063<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
5064<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
5065state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
5066practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
5067that were allocated after the <tt>llvm.stacksave</tt> was executed.
5068</p>
5069
5070</div>
5071
5072<!-- _______________________________________________________________________ -->
5073<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5074 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5075</div>
5076
5077<div class="doc_text">
5078
5079<h5>Syntax:</h5>
5080<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5081 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5082</pre>
5083
5084<h5>Overview:</h5>
5085
5086<p>
5087The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5088the function stack to the state it was in when the corresponding <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5089href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5090useful for implementing language features like scoped automatic variable sized
5091arrays in C99.
5092</p>
5093
5094<h5>Semantics:</h5>
5095
5096<p>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5097See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5098</p>
5099
5100</div>
5101
5102
5103<!-- _______________________________________________________________________ -->
5104<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5105 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5106</div>
5107
5108<div class="doc_text">
5109
5110<h5>Syntax:</h5>
5111<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5112 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]5113</pre>
5114
5115<h5>Overview:</h5>
5116
5117
5118<p>
5119The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5120a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
5121no
5122effect on the behavior of the program but can change its performance
Chris Lattner2a615362005-02-28 19:47:14 +0000[diff] [blame]5123characteristics.
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5124</p>
5125
5126<h5>Arguments:</h5>
5127
5128<p>
5129<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
5130determining if the fetch should be for a read (0) or write (1), and
5131<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattneraeffb4a2005-03-07 20:31:38 +0000[diff] [blame]5132locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5133<tt>locality</tt> arguments must be constant integers.
5134</p>
5135
5136<h5>Semantics:</h5>
5137
5138<p>
5139This intrinsic does not modify the behavior of the program. In particular,
5140prefetches cannot trap and do not produce a value. On targets that support this
5141intrinsic, the prefetch can provide hints to the processor cache for better
5142performance.
5143</p>
5144
5145</div>
5146
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5147<!-- _______________________________________________________________________ -->
5148<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5149 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5150</div>
5151
5152<div class="doc_text">
5153
5154<h5>Syntax:</h5>
5155<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5156 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5157</pre>
5158
5159<h5>Overview:</h5>
5160
5161
5162<p>
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5163The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5164(PC) in a region of
5165code to simulators and other tools. The method is target specific, but it is
5166expected that the marker will use exported symbols to transmit the PC of the
5167marker.
5168The marker makes no guarantees that it will remain with any specific instruction
5169after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb3e7afd2006-03-24 07:16:10 +0000[diff] [blame]5170optimizations. The intended use is to be inserted after optimizations to allow
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5171correlations of simulation runs.
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5172</p>
5173
5174<h5>Arguments:</h5>
5175
5176<p>
5177<tt>id</tt> is a numerical id identifying the marker.
5178</p>
5179
5180<h5>Semantics:</h5>
5181
5182<p>
5183This intrinsic does not modify the behavior of the program. Backends that do not
5184support this intrinisic may ignore it.
5185</p>
5186
5187</div>
5188
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5189<!-- _______________________________________________________________________ -->
5190<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5191 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5192</div>
5193
5194<div class="doc_text">
5195
5196<h5>Syntax:</h5>
5197<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5198 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5199</pre>
5200
5201<h5>Overview:</h5>
5202
5203
5204<p>
5205The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5206counter register (or similar low latency, high accuracy clocks) on those targets
5207that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
5208As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
5209should only be used for small timings.
5210</p>
5211
5212<h5>Semantics:</h5>
5213
5214<p>
5215When directly supported, reading the cycle counter should not modify any memory.
5216Implementations are allowed to either return a application specific value or a
5217system wide value. On backends without support, this is lowered to a constant 0.
5218</p>
5219
5220</div>
5221
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5222<!-- ======================================================================= -->
5223<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5224 <a name="int_libc">Standard C Library Intrinsics</a>
5225</div>
5226
5227<div class="doc_text">
5228<p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5229LLVM provides intrinsics for a few important standard C library functions.
5230These intrinsics allow source-language front-ends to pass information about the
5231alignment of the pointer arguments to the code generator, providing opportunity
5232for more efficient code generation.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5233</p>
5234
5235</div>
5236
5237<!-- _______________________________________________________________________ -->
5238<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5239 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5240</div>
5241
5242<div class="doc_text">
5243
5244<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5245<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
5246width. Not all targets support all bit widths however.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5247<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5248 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5249 i8 &lt;len&gt;, i32 &lt;align&gt;)
5250 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5251 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5252 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5253 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5254 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5255 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5256</pre>
5257
5258<h5>Overview:</h5>
5259
5260<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5261The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5262location to the destination location.
5263</p>
5264
5265<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5266Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5267intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5268</p>
5269
5270<h5>Arguments:</h5>
5271
5272<p>
5273The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5274the source. The third argument is an integer argument
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5275specifying the number of bytes to copy, and the fourth argument is the alignment
5276of the source and destination locations.
5277</p>
5278
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5279<p>
5280If 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]5281the caller guarantees that both the source and destination pointers are aligned
5282to that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5283</p>
5284
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5285<h5>Semantics:</h5>
5286
5287<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5288The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5289location to the destination location, which are not allowed to overlap. It
5290copies "len" bytes of memory over. If the argument is known to be aligned to
5291some boundary, this can be specified as the fourth argument, otherwise it should
5292be set to 0 or 1.
5293</p>
5294</div>
5295
5296
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5297<!-- _______________________________________________________________________ -->
5298<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5299 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5300</div>
5301
5302<div class="doc_text">
5303
5304<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5305<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
5306width. Not all targets support all bit widths however.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5307<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5308 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5309 i8 &lt;len&gt;, i32 &lt;align&gt;)
5310 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5311 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5312 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5313 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5314 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5315 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5316</pre>
5317
5318<h5>Overview:</h5>
5319
5320<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5321The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
5322location to the destination location. It is similar to the
Chris Lattner4b2cbcf2008-01-06 19:51:52 +0000[diff] [blame]5323'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5324</p>
5325
5326<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5327Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5328intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5329</p>
5330
5331<h5>Arguments:</h5>
5332
5333<p>
5334The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5335the source. The third argument is an integer argument
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5336specifying the number of bytes to copy, and the fourth argument is the alignment
5337of the source and destination locations.
5338</p>
5339
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5340<p>
5341If 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]5342the caller guarantees that the source and destination pointers are aligned to
5343that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5344</p>
5345
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5346<h5>Semantics:</h5>
5347
5348<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5349The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5350location to the destination location, which may overlap. It
5351copies "len" bytes of memory over. If the argument is known to be aligned to
5352some boundary, this can be specified as the fourth argument, otherwise it should
5353be set to 0 or 1.
5354</p>
5355</div>
5356
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5357
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5358<!-- _______________________________________________________________________ -->
5359<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5360 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5361</div>
5362
5363<div class="doc_text">
5364
5365<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5366<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
5367width. Not all targets support all bit widths however.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5368<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5369 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5370 i8 &lt;len&gt;, i32 &lt;align&gt;)
5371 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5372 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5373 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5374 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5375 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5376 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5377</pre>
5378
5379<h5>Overview:</h5>
5380
5381<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5382The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5383byte value.
5384</p>
5385
5386<p>
5387Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
5388does not return a value, and takes an extra alignment argument.
5389</p>
5390
5391<h5>Arguments:</h5>
5392
5393<p>
5394The first argument is a pointer to the destination to fill, the second is the
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5395byte value to fill it with, the third argument is an integer
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5396argument specifying the number of bytes to fill, and the fourth argument is the
5397known alignment of destination location.
5398</p>
5399
5400<p>
5401If 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]5402the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5403</p>
5404
5405<h5>Semantics:</h5>
5406
5407<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5408The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
5409the
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5410destination location. If the argument is known to be aligned to some boundary,
5411this can be specified as the fourth argument, otherwise it should be set to 0 or
54121.
5413</p>
5414</div>
5415
5416
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5417<!-- _______________________________________________________________________ -->
5418<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5419 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5420</div>
5421
5422<div class="doc_text">
5423
5424<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5425<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]5426floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5427types however.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5428<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5429 declare float @llvm.sqrt.f32(float %Val)
5430 declare double @llvm.sqrt.f64(double %Val)
5431 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5432 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5433 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5434</pre>
5435
5436<h5>Overview:</h5>
5437
5438<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5439The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5440returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5441<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner103e2d72008-01-29 07:00:44 +0000[diff] [blame]5442negative numbers other than -0.0 (which allows for better optimization, because
5443there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
5444defined to return -0.0 like IEEE sqrt.
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5445</p>
5446
5447<h5>Arguments:</h5>
5448
5449<p>
5450The argument and return value are floating point numbers of the same type.
5451</p>
5452
5453<h5>Semantics:</h5>
5454
5455<p>
Dan Gohmand6257fe2007-07-16 14:37:41 +0000[diff] [blame]5456This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5457floating point number.
5458</p>
5459</div>
5460
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5461<!-- _______________________________________________________________________ -->
5462<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5463 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5464</div>
5465
5466<div class="doc_text">
5467
5468<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5469<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]5470floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5471types however.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5472<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5473 declare float @llvm.powi.f32(float %Val, i32 %power)
5474 declare double @llvm.powi.f64(double %Val, i32 %power)
5475 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5476 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5477 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5478</pre>
5479
5480<h5>Overview:</h5>
5481
5482<p>
5483The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5484specified (positive or negative) power. The order of evaluation of
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5485multiplications is not defined. When a vector of floating point type is
5486used, the second argument remains a scalar integer value.
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5487</p>
5488
5489<h5>Arguments:</h5>
5490
5491<p>
5492The second argument is an integer power, and the first is a value to raise to
5493that power.
5494</p>
5495
5496<h5>Semantics:</h5>
5497
5498<p>
5499This function returns the first value raised to the second power with an
5500unspecified sequence of rounding operations.</p>
5501</div>
5502
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5503<!-- _______________________________________________________________________ -->
5504<div class="doc_subsubsection">
5505 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5506</div>
5507
5508<div class="doc_text">
5509
5510<h5>Syntax:</h5>
5511<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5512floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5513types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5514<pre>
5515 declare float @llvm.sin.f32(float %Val)
5516 declare double @llvm.sin.f64(double %Val)
5517 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5518 declare fp128 @llvm.sin.f128(fp128 %Val)
5519 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5520</pre>
5521
5522<h5>Overview:</h5>
5523
5524<p>
5525The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
5526</p>
5527
5528<h5>Arguments:</h5>
5529
5530<p>
5531The argument and return value are floating point numbers of the same type.
5532</p>
5533
5534<h5>Semantics:</h5>
5535
5536<p>
5537This function returns the sine of the specified operand, returning the
5538same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5539conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5540</div>
5541
5542<!-- _______________________________________________________________________ -->
5543<div class="doc_subsubsection">
5544 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5545</div>
5546
5547<div class="doc_text">
5548
5549<h5>Syntax:</h5>
5550<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5551floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5552types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5553<pre>
5554 declare float @llvm.cos.f32(float %Val)
5555 declare double @llvm.cos.f64(double %Val)
5556 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5557 declare fp128 @llvm.cos.f128(fp128 %Val)
5558 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5559</pre>
5560
5561<h5>Overview:</h5>
5562
5563<p>
5564The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
5565</p>
5566
5567<h5>Arguments:</h5>
5568
5569<p>
5570The argument and return value are floating point numbers of the same type.
5571</p>
5572
5573<h5>Semantics:</h5>
5574
5575<p>
5576This function returns the cosine of the specified operand, returning the
5577same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5578conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5579</div>
5580
5581<!-- _______________________________________________________________________ -->
5582<div class="doc_subsubsection">
5583 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5584</div>
5585
5586<div class="doc_text">
5587
5588<h5>Syntax:</h5>
5589<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5590floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5591types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5592<pre>
5593 declare float @llvm.pow.f32(float %Val, float %Power)
5594 declare double @llvm.pow.f64(double %Val, double %Power)
5595 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5596 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5597 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5598</pre>
5599
5600<h5>Overview:</h5>
5601
5602<p>
5603The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5604specified (positive or negative) power.
5605</p>
5606
5607<h5>Arguments:</h5>
5608
5609<p>
5610The second argument is a floating point power, and the first is a value to
5611raise to that power.
5612</p>
5613
5614<h5>Semantics:</h5>
5615
5616<p>
5617This function returns the first value raised to the second power,
5618returning the
5619same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5620conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5621</div>
5622
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5623
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5624<!-- ======================================================================= -->
5625<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5626 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5627</div>
5628
5629<div class="doc_text">
5630<p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5631LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5632These allow efficient code generation for some algorithms.
5633</p>
5634
5635</div>
5636
5637<!-- _______________________________________________________________________ -->
5638<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5639 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5640</div>
5641
5642<div class="doc_text">
5643
5644<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5645<p>This is an overloaded intrinsic function. You can use bswap on any integer
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5646type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5647<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5648 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5649 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5650 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5651</pre>
5652
5653<h5>Overview:</h5>
5654
5655<p>
Reid Spencer338ea092007-04-02 02:25:19 +0000[diff] [blame]5656The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5657values with an even number of bytes (positive multiple of 16 bits). These are
5658useful for performing operations on data that is not in the target's native
5659byte order.
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5660</p>
5661
5662<h5>Semantics:</h5>
5663
5664<p>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5665The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5666and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
5667intrinsic returns an i32 value that has the four bytes of the input i32
5668swapped, 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]5669i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
5670<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5671additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5672</p>
5673
5674</div>
5675
5676<!-- _______________________________________________________________________ -->
5677<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5678 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5679</div>
5680
5681<div class="doc_text">
5682
5683<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5684<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5685width. Not all targets support all bit widths however.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5686<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5687 declare i8 @llvm.ctpop.i8 (i8 &lt;src&gt;)
5688 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5689 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5690 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5691 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5692</pre>
5693
5694<h5>Overview:</h5>
5695
5696<p>
Chris Lattnerec6cb612006-01-16 22:38:59 +0000[diff] [blame]5697The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
5698value.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5699</p>
5700
5701<h5>Arguments:</h5>
5702
5703<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]5704The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5705integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5706</p>
5707
5708<h5>Semantics:</h5>
5709
5710<p>
5711The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
5712</p>
5713</div>
5714
5715<!-- _______________________________________________________________________ -->
5716<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5717 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5718</div>
5719
5720<div class="doc_text">
5721
5722<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5723<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5724integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5725<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5726 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5727 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5728 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5729 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5730 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5731</pre>
5732
5733<h5>Overview:</h5>
5734
5735<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5736The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5737leading zeros in a variable.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5738</p>
5739
5740<h5>Arguments:</h5>
5741
5742<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]5743The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5744integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5745</p>
5746
5747<h5>Semantics:</h5>
5748
5749<p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5750The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
5751in 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]5752of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5753</p>
5754</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5755
5756
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5757
5758<!-- _______________________________________________________________________ -->
5759<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5760 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5761</div>
5762
5763<div class="doc_text">
5764
5765<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5766<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5767integer bit width. Not all targets support all bit widths however.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5768<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5769 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5770 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5771 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5772 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5773 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5774</pre>
5775
5776<h5>Overview:</h5>
5777
5778<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5779The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5780trailing zeros.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5781</p>
5782
5783<h5>Arguments:</h5>
5784
5785<p>
5786The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5787integer type. The return type must match the argument type.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5788</p>
5789
5790<h5>Semantics:</h5>
5791
5792<p>
5793The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
5794in a variable. If the src == 0 then the result is the size in bits of the type
5795of src. For example, <tt>llvm.cttz(2) = 1</tt>.
5796</p>
5797</div>
5798
Reid Spencer497d93e2007-04-01 08:27:01 +0000[diff] [blame]5799<!-- _______________________________________________________________________ -->
5800<div class="doc_subsubsection">
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5801 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5802</div>
5803
5804<div class="doc_text">
5805
5806<h5>Syntax:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5807<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5808on any integer bit width.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5809<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5810 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
5811 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5812</pre>
5813
5814<h5>Overview:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5815<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5816range of bits from an integer value and returns them in the same bit width as
5817the original value.</p>
5818
5819<h5>Arguments:</h5>
5820<p>The first argument, <tt>%val</tt> and the result may be integer types of
5821any bit width but they must have the same bit width. The second and third
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5822arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5823
5824<h5>Semantics:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5825<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5826of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
5827<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
5828operates in forward mode.</p>
5829<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
5830right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5831only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
5832<ol>
5833 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
5834 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
5835 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
5836 to determine the number of bits to retain.</li>
5837 <li>A mask of the retained bits is created by shifting a -1 value.</li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5838 <li>The mask is ANDed with <tt>%val</tt> to produce the result.</li>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5839</ol>
Reid Spencerd6a85b52007-05-14 16:14:57 +0000[diff] [blame]5840<p>In reverse mode, a similar computation is made except that the bits are
5841returned in the reverse order. So, for example, if <tt>X</tt> has the value
5842<tt>i16 0x0ACF (101011001111)</tt> and we apply
5843<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
5844<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5845</div>
5846
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5847<div class="doc_subsubsection">
5848 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
5849</div>
5850
5851<div class="doc_text">
5852
5853<h5>Syntax:</h5>
5854<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5855on any integer bit width.</p>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5856<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5857 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
5858 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]5859</pre>
5860
5861<h5>Overview:</h5>
5862<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
5863of bits in an integer value with another integer value. It returns the integer
5864with the replaced bits.</p>
5865
5866<h5>Arguments:</h5>
5867<p>The first argument, <tt>%val</tt> and the result may be integer types of
5868any bit width but they must have the same bit width. <tt>%val</tt> is the value
5869whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
5870integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
5871type since they specify only a bit index.</p>
5872
5873<h5>Semantics:</h5>
5874<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
5875of operation: forwards and reverse. If <tt>%lo</tt> is greater than
5876<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
5877operates in forward mode.</p>
5878<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
5879truncating it down to the size of the replacement area or zero extending it
5880up to that size.</p>
5881<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5882are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5883in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5884to the <tt>%hi</tt>th bit.</p>
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5885<p>In reverse mode, a similar computation is made except that the bits are
5886reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5887<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.</p>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5888<h5>Examples:</h5>
5889<pre>
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5890 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5891 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5892 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5893 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5894 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]5895</pre>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5896</div>
5897
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5898<!-- ======================================================================= -->
5899<div class="doc_subsection">
5900 <a name="int_debugger">Debugger Intrinsics</a>
5901</div>
5902
5903<div class="doc_text">
5904<p>
5905The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
5906are described in the <a
5907href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
5908Debugging</a> document.
5909</p>
5910</div>
5911
5912
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]5913<!-- ======================================================================= -->
5914<div class="doc_subsection">
5915 <a name="int_eh">Exception Handling Intrinsics</a>
5916</div>
5917
5918<div class="doc_text">
5919<p> The LLVM exception handling intrinsics (which all start with
5920<tt>llvm.eh.</tt> prefix), are described in the <a
5921href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
5922Handling</a> document. </p>
5923</div>
5924
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5925<!-- ======================================================================= -->
5926<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5927 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5928</div>
5929
5930<div class="doc_text">
5931<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5932 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5933 the <tt>nest</tt> attribute, from a function. The result is a callable
5934 function pointer lacking the nest parameter - the caller does not need
5935 to provide a value for it. Instead, the value to use is stored in
5936 advance in a "trampoline", a block of memory usually allocated
5937 on the stack, which also contains code to splice the nest value into the
5938 argument list. This is used to implement the GCC nested function address
5939 extension.
5940</p>
5941<p>
5942 For example, if the function is
5943 <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]5944 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]5945<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5946 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
5947 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
5948 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
5949 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5950</pre>
Bill Wendling03295ca2007-09-22 09:23:55 +0000[diff] [blame]5951 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
5952 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5953</div>
5954
5955<!-- _______________________________________________________________________ -->
5956<div class="doc_subsubsection">
5957 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
5958</div>
5959<div class="doc_text">
5960<h5>Syntax:</h5>
5961<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5962declare 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]5963</pre>
5964<h5>Overview:</h5>
5965<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5966 This fills the memory pointed to by <tt>tramp</tt> with code
5967 and returns a function pointer suitable for executing it.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5968</p>
5969<h5>Arguments:</h5>
5970<p>
5971 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
5972 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
5973 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsc00c2ba2007-08-22 23:39:54 +0000[diff] [blame]5974 intrinsic. Note that the size and the alignment are target-specific - LLVM
5975 currently provides no portable way of determining them, so a front-end that
5976 generates this intrinsic needs to have some target-specific knowledge.
5977 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]5978</p>
5979<h5>Semantics:</h5>
5980<p>
5981 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5982 dependent code, turning it into a function. A pointer to this function is
5983 returned, but needs to be bitcast to an
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5984 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5985 before being called. The new function's signature is the same as that of
5986 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
5987 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
5988 of pointer type. Calling the new function is equivalent to calling
5989 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
5990 missing <tt>nest</tt> argument. If, after calling
5991 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
5992 modified, then the effect of any later call to the returned function pointer is
5993 undefined.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5994</p>
5995</div>
5996
5997<!-- ======================================================================= -->
5998<div class="doc_subsection">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]5999 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
6000</div>
6001
6002<div class="doc_text">
6003<p>
6004 These intrinsic functions expand the "universal IR" of LLVM to represent
6005 hardware constructs for atomic operations and memory synchronization. This
6006 provides an interface to the hardware, not an interface to the programmer. It
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]6007 is aimed at a low enough level to allow any programming models or APIs
6008 (Application Programming Interfaces) which
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6009 need atomic behaviors to map cleanly onto it. It is also modeled primarily on
6010 hardware behavior. Just as hardware provides a "universal IR" for source
6011 languages, it also provides a starting point for developing a "universal"
6012 atomic operation and synchronization IR.
6013</p>
6014<p>
6015 These do <em>not</em> form an API such as high-level threading libraries,
6016 software transaction memory systems, atomic primitives, and intrinsic
6017 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
6018 application libraries. The hardware interface provided by LLVM should allow
6019 a clean implementation of all of these APIs and parallel programming models.
6020 No one model or paradigm should be selected above others unless the hardware
6021 itself ubiquitously does so.
6022
6023</p>
6024</div>
6025
6026<!-- _______________________________________________________________________ -->
6027<div class="doc_subsubsection">
6028 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
6029</div>
6030<div class="doc_text">
6031<h5>Syntax:</h5>
6032<pre>
6033declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;,
6034i1 &lt;device&gt; )
6035
6036</pre>
6037<h5>Overview:</h5>
6038<p>
6039 The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
6040 specific pairs of memory access types.
6041</p>
6042<h5>Arguments:</h5>
6043<p>
6044 The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
6045 The first four arguments enables a specific barrier as listed below. The fith
6046 argument specifies that the barrier applies to io or device or uncached memory.
6047
6048</p>
6049 <ul>
6050 <li><tt>ll</tt>: load-load barrier</li>
6051 <li><tt>ls</tt>: load-store barrier</li>
6052 <li><tt>sl</tt>: store-load barrier</li>
6053 <li><tt>ss</tt>: store-store barrier</li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6054 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6055 </ul>
6056<h5>Semantics:</h5>
6057<p>
6058 This intrinsic causes the system to enforce some ordering constraints upon
6059 the loads and stores of the program. This barrier does not indicate
6060 <em>when</em> any events will occur, it only enforces an <em>order</em> in
6061 which they occur. For any of the specified pairs of load and store operations
6062 (f.ex. load-load, or store-load), all of the first operations preceding the
6063 barrier will complete before any of the second operations succeeding the
6064 barrier begin. Specifically the semantics for each pairing is as follows:
6065</p>
6066 <ul>
6067 <li><tt>ll</tt>: All loads before the barrier must complete before any load
6068 after the barrier begins.</li>
6069
6070 <li><tt>ls</tt>: All loads before the barrier must complete before any
6071 store after the barrier begins.</li>
6072 <li><tt>ss</tt>: All stores before the barrier must complete before any
6073 store after the barrier begins.</li>
6074 <li><tt>sl</tt>: All stores before the barrier must complete before any
6075 load after the barrier begins.</li>
6076 </ul>
6077<p>
6078 These semantics are applied with a logical "and" behavior when more than one
6079 is enabled in a single memory barrier intrinsic.
6080</p>
6081<p>
6082 Backends may implement stronger barriers than those requested when they do not
6083 support as fine grained a barrier as requested. Some architectures do not
6084 need all types of barriers and on such architectures, these become noops.
6085</p>
6086<h5>Example:</h5>
6087<pre>
6088%ptr = malloc i32
6089 store i32 4, %ptr
6090
6091%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
6092 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
6093 <i>; guarantee the above finishes</i>
6094 store i32 8, %ptr <i>; before this begins</i>
6095</pre>
6096</div>
6097
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6098<!-- _______________________________________________________________________ -->
6099<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6100 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6101</div>
6102<div class="doc_text">
6103<h5>Syntax:</h5>
6104<p>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6105 This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
6106 any integer bit width and for different address spaces. Not all targets
6107 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6108
6109<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6110declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6111declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6112declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
6113declare 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]6114
6115</pre>
6116<h5>Overview:</h5>
6117<p>
6118 This loads a value in memory and compares it to a given value. If they are
6119 equal, it stores a new value into the memory.
6120</p>
6121<h5>Arguments:</h5>
6122<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6123 The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6124 well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
6125 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
6126 this integer type. While any bit width integer may be used, targets may only
6127 lower representations they support in hardware.
6128
6129</p>
6130<h5>Semantics:</h5>
6131<p>
6132 This entire intrinsic must be executed atomically. It first loads the value
6133 in memory pointed to by <tt>ptr</tt> and compares it with the value
6134 <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
6135 loaded value is yielded in all cases. This provides the equivalent of an
6136 atomic compare-and-swap operation within the SSA framework.
6137</p>
6138<h5>Examples:</h5>
6139
6140<pre>
6141%ptr = malloc i32
6142 store i32 4, %ptr
6143
6144%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6145%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6146 <i>; yields {i32}:result1 = 4</i>
6147%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6148%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6149
6150%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6151%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6152 <i>; yields {i32}:result2 = 8</i>
6153%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6154
6155%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6156</pre>
6157</div>
6158
6159<!-- _______________________________________________________________________ -->
6160<div class="doc_subsubsection">
6161 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6162</div>
6163<div class="doc_text">
6164<h5>Syntax:</h5>
6165
6166<p>
6167 This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6168 integer bit width. Not all targets support all bit widths however.</p>
6169<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6170declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6171declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6172declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6173declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6174
6175</pre>
6176<h5>Overview:</h5>
6177<p>
6178 This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6179 the value from memory. It then stores the value in <tt>val</tt> in the memory
6180 at <tt>ptr</tt>.
6181</p>
6182<h5>Arguments:</h5>
6183
6184<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6185 The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6186 <tt>val</tt> argument and the result must be integers of the same bit width.
6187 The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6188 integer type. The targets may only lower integer representations they
6189 support.
6190</p>
6191<h5>Semantics:</h5>
6192<p>
6193 This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6194 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6195 equivalent of an atomic swap operation within the SSA framework.
6196
6197</p>
6198<h5>Examples:</h5>
6199<pre>
6200%ptr = malloc i32
6201 store i32 4, %ptr
6202
6203%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6204%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6205 <i>; yields {i32}:result1 = 4</i>
6206%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6207%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6208
6209%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6210%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6211 <i>; yields {i32}:result2 = 8</i>
6212
6213%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6214%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6215</pre>
6216</div>
6217
6218<!-- _______________________________________________________________________ -->
6219<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6220 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6221
6222</div>
6223<div class="doc_text">
6224<h5>Syntax:</h5>
6225<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6226 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]6227 integer bit width. Not all targets support all bit widths however.</p>
6228<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6229declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6230declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6231declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6232declare 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]6233
6234</pre>
6235<h5>Overview:</h5>
6236<p>
6237 This intrinsic adds <tt>delta</tt> to the value stored in memory at
6238 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6239</p>
6240<h5>Arguments:</h5>
6241<p>
6242
6243 The intrinsic takes two arguments, the first a pointer to an integer value
6244 and the second an integer value. The result is also an integer value. These
6245 integer types can have any bit width, but they must all have the same bit
6246 width. The targets may only lower integer representations they support.
6247</p>
6248<h5>Semantics:</h5>
6249<p>
6250 This intrinsic does a series of operations atomically. It first loads the
6251 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6252 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6253</p>
6254
6255<h5>Examples:</h5>
6256<pre>
6257%ptr = malloc i32
6258 store i32 4, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6259%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6260 <i>; yields {i32}:result1 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6261%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6262 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6263%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6264 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6265%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6266</pre>
6267</div>
6268
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6269<!-- _______________________________________________________________________ -->
6270<div class="doc_subsubsection">
6271 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6272
6273</div>
6274<div class="doc_text">
6275<h5>Syntax:</h5>
6276<p>
6277 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]6278 any integer bit width and for different address spaces. Not all targets
6279 support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6280<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6281declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6282declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6283declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6284declare 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]6285
6286</pre>
6287<h5>Overview:</h5>
6288<p>
6289 This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6290 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6291</p>
6292<h5>Arguments:</h5>
6293<p>
6294
6295 The intrinsic takes two arguments, the first a pointer to an integer value
6296 and the second an integer value. The result is also an integer value. These
6297 integer types can have any bit width, but they must all have the same bit
6298 width. The targets may only lower integer representations they support.
6299</p>
6300<h5>Semantics:</h5>
6301<p>
6302 This intrinsic does a series of operations atomically. It first loads the
6303 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6304 result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6305</p>
6306
6307<h5>Examples:</h5>
6308<pre>
6309%ptr = malloc i32
6310 store i32 8, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6311%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6312 <i>; yields {i32}:result1 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6313%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6314 <i>; yields {i32}:result2 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6315%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6316 <i>; yields {i32}:result3 = 2</i>
6317%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6318</pre>
6319</div>
6320
6321<!-- _______________________________________________________________________ -->
6322<div class="doc_subsubsection">
6323 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6324 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6325 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6326 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
6327
6328</div>
6329<div class="doc_text">
6330<h5>Syntax:</h5>
6331<p>
6332 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
6333 <tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6334 <tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
6335 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6336<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6337declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6338declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6339declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6340declare 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]6341
6342</pre>
6343
6344<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6345declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6346declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6347declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6348declare 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]6349
6350</pre>
6351
6352<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6353declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6354declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6355declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6356declare 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]6357
6358</pre>
6359
6360<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6361declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6362declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6363declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6364declare 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]6365
6366</pre>
6367<h5>Overview:</h5>
6368<p>
6369 These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6370 the value stored in memory at <tt>ptr</tt>. It yields the original value
6371 at <tt>ptr</tt>.
6372</p>
6373<h5>Arguments:</h5>
6374<p>
6375
6376 These intrinsics take two arguments, the first a pointer to an integer value
6377 and the second an integer value. The result is also an integer value. These
6378 integer types can have any bit width, but they must all have the same bit
6379 width. The targets may only lower integer representations they support.
6380</p>
6381<h5>Semantics:</h5>
6382<p>
6383 These intrinsics does a series of operations atomically. They first load the
6384 value stored at <tt>ptr</tt>. They then do the bitwise operation
6385 <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
6386 value stored at <tt>ptr</tt>.
6387</p>
6388
6389<h5>Examples:</h5>
6390<pre>
6391%ptr = malloc i32
6392 store i32 0x0F0F, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6393%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6394 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6395%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6396 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6397%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6398 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6399%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6400 <i>; yields {i32}:result3 = FF</i>
6401%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6402</pre>
6403</div>
6404
6405
6406<!-- _______________________________________________________________________ -->
6407<div class="doc_subsubsection">
6408 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6409 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6410 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6411 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
6412
6413</div>
6414<div class="doc_text">
6415<h5>Syntax:</h5>
6416<p>
6417 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6418 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6419 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6420 address spaces. Not all targets
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6421 support all bit widths however.</p>
6422<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6423declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6424declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6425declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6426declare 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]6427
6428</pre>
6429
6430<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6431declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6432declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6433declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6434declare 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]6435
6436</pre>
6437
6438<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6439declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6440declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6441declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6442declare 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]6443
6444</pre>
6445
6446<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6447declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6448declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6449declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6450declare 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]6451
6452</pre>
6453<h5>Overview:</h5>
6454<p>
6455 These intrinsics takes the signed or unsigned minimum or maximum of
6456 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6457 original value at <tt>ptr</tt>.
6458</p>
6459<h5>Arguments:</h5>
6460<p>
6461
6462 These intrinsics take two arguments, the first a pointer to an integer value
6463 and the second an integer value. The result is also an integer value. These
6464 integer types can have any bit width, but they must all have the same bit
6465 width. The targets may only lower integer representations they support.
6466</p>
6467<h5>Semantics:</h5>
6468<p>
6469 These intrinsics does a series of operations atomically. They first load the
6470 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
6471 <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
6472 the original value stored at <tt>ptr</tt>.
6473</p>
6474
6475<h5>Examples:</h5>
6476<pre>
6477%ptr = malloc i32
6478 store i32 7, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6479%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6480 <i>; yields {i32}:result0 = 7</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6481%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6482 <i>; yields {i32}:result1 = -2</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6483%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6484 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6485%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6486 <i>; yields {i32}:result3 = 8</i>
6487%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6488</pre>
6489</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6490
6491<!-- ======================================================================= -->
6492<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6493 <a name="int_general">General Intrinsics</a>
6494</div>
6495
6496<div class="doc_text">
6497<p> This class of intrinsics is designed to be generic and has
6498no specific purpose. </p>
6499</div>
6500
6501<!-- _______________________________________________________________________ -->
6502<div class="doc_subsubsection">
6503 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6504</div>
6505
6506<div class="doc_text">
6507
6508<h5>Syntax:</h5>
6509<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]6510 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]6511</pre>
6512
6513<h5>Overview:</h5>
6514
6515<p>
6516The '<tt>llvm.var.annotation</tt>' intrinsic
6517</p>
6518
6519<h5>Arguments:</h5>
6520
6521<p>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]6522The first argument is a pointer to a value, the second is a pointer to a
6523global string, the third is a pointer to a global string which is the source
6524file name, and the last argument is the line number.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6525</p>
6526
6527<h5>Semantics:</h5>
6528
6529<p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6530This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6531This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6532annotations. These have no other defined use, they are ignored by code
6533generation and optimization.
6534</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6535</div>
6536
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6537<!-- _______________________________________________________________________ -->
6538<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]6539 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6540</div>
6541
6542<div class="doc_text">
6543
6544<h5>Syntax:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6545<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6546any integer bit width.
6547</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6548<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]6549 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6550 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6551 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6552 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6553 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]6554</pre>
6555
6556<h5>Overview:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6557
6558<p>
6559The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6560</p>
6561
6562<h5>Arguments:</h5>
6563
6564<p>
6565The first argument is an integer value (result of some expression),
6566the second is a pointer to a global string, the third is a pointer to a global
6567string which is the source file name, and the last argument is the line number.
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6568It returns the value of the first argument.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6569</p>
6570
6571<h5>Semantics:</h5>
6572
6573<p>
6574This intrinsic allows annotations to be put on arbitrary expressions
6575with arbitrary strings. This can be useful for special purpose optimizations
6576that want to look for these annotations. These have no other defined use, they
6577are ignored by code generation and optimization.
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6578</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6579</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6580
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6581<!-- _______________________________________________________________________ -->
6582<div class="doc_subsubsection">
6583 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6584</div>
6585
6586<div class="doc_text">
6587
6588<h5>Syntax:</h5>
6589<pre>
6590 declare void @llvm.trap()
6591</pre>
6592
6593<h5>Overview:</h5>
6594
6595<p>
6596The '<tt>llvm.trap</tt>' intrinsic
6597</p>
6598
6599<h5>Arguments:</h5>
6600
6601<p>
6602None
6603</p>
6604
6605<h5>Semantics:</h5>
6606
6607<p>
6608This intrinsics is lowered to the target dependent trap instruction. If the
6609target does not have a trap instruction, this intrinsic will be lowered to the
6610call of the abort() function.
6611</p>
6612</div>
6613
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6614<!-- _______________________________________________________________________ -->
6615<div class="doc_subsubsection">
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]6616 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6617</div>
6618<div class="doc_text">
6619<h5>Syntax:</h5>
6620<pre>
6621declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
6622
6623</pre>
6624<h5>Overview:</h5>
6625<p>
6626 The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
6627 it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
6628 it is placed on the stack before local variables.
6629</p>
6630<h5>Arguments:</h5>
6631<p>
6632 The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
6633 first argument is the value loaded from the stack guard
6634 <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
6635 has enough space to hold the value of the guard.
6636</p>
6637<h5>Semantics:</h5>
6638<p>
6639 This intrinsic causes the prologue/epilogue inserter to force the position of
6640 the <tt>AllocaInst</tt> stack slot to be before local variables on the
6641 stack. This is to ensure that if a local variable on the stack is overwritten,
6642 it will destroy the value of the guard. When the function exits, the guard on
6643 the stack is checked against the original guard. If they're different, then
6644 the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
6645</p>
6646</div>
6647
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6648<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6649<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6650<address>
6651 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]6652 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6653 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]6654 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6655
6656 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]6657 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6658 Last modified: $Date$
6659</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]6660
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6661</body>
6662</html>