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5 <title>LLVM Assembly Language Reference Manual</title>
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9 content="LLVM Assembly Language Reference Manual.">
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11</head>
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Chris Lattnerd7923912004-05-23 21:06:01 +000014
Chris Lattner261efe92003-11-25 01:02:51 +000015<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner00950542001-06-06 20:29:01 +000016<ol>
Misha Brukman9d0919f2003-11-08 01:05:38 +000017 <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 +000020 <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 +000023 <li><a href="#linkage">Linkage Types</a></li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +000024 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +000025 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +000026 <li><a href="#functionstructure">Functions</a></li>
Anton Korobeynikovc6c98af2007-04-29 18:02:48 +000027 <li><a href="#aliasstructure">Aliases</a>
Reid Spencerca86e162006-12-31 07:07:53 +000028 <li><a href="#paramattrs">Parameter Attributes</a></li>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +000029 <li><a href="#gc">Garbage Collector Names</a></li>
Devang Patelcdc06692008-09-04 23:10:26 +000030 <li><a href="#notes">Function Notes</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +000031 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencerde151942007-02-19 23:54:10 +000032 <li><a href="#datalayout">Data Layout</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +000033 </ol>
34 </li>
Chris Lattner00950542001-06-06 20:29:01 +000035 <li><a href="#typesystem">Type System</a>
36 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +000037 <li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +000038 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +000039 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +000040 <li><a href="#t_floating">Floating Point Types</a></li>
41 <li><a href="#t_void">Void Type</a></li>
42 <li><a href="#t_label">Label Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +000043 </ol>
44 </li>
Chris Lattner00950542001-06-06 20:29:01 +000045 <li><a href="#t_derived">Derived Types</a>
46 <ol>
Chris Lattnerb9488a62007-12-18 06:18:21 +000047 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +000048 <li><a href="#t_array">Array Type</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +000049 <li><a href="#t_function">Function Type</a></li>
50 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +000051 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth75e10682006-12-08 17:13:00 +000052 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer485bad12007-02-15 03:07:05 +000053 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner69c11bb2005-04-25 17:34:15 +000054 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +000055 </ol>
56 </li>
57 </ol>
58 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +000059 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +000060 <ol>
61 <li><a href="#simpleconstants">Simple Constants</a>
62 <li><a href="#aggregateconstants">Aggregate Constants</a>
63 <li><a href="#globalconstants">Global Variable and Function Addresses</a>
64 <li><a href="#undefvalues">Undefined Values</a>
65 <li><a href="#constantexprs">Constant Expressions</a>
66 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +000067 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +000068 <li><a href="#othervalues">Other Values</a>
69 <ol>
70 <li><a href="#inlineasm">Inline Assembler Expressions</a>
71 </ol>
72 </li>
Chris Lattner00950542001-06-06 20:29:01 +000073 <li><a href="#instref">Instruction Reference</a>
74 <ol>
75 <li><a href="#terminators">Terminator Instructions</a>
76 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +000077 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
78 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +000079 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
80 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +000081 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +000082 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +000083 </ol>
84 </li>
Chris Lattner00950542001-06-06 20:29:01 +000085 <li><a href="#binaryops">Binary Operations</a>
86 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +000087 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
88 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
89 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +000090 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
91 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
92 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +000093 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
94 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
95 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +000096 </ol>
97 </li>
Chris Lattner00950542001-06-06 20:29:01 +000098 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
99 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000100 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
101 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
102 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000103 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000104 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000105 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000106 </ol>
107 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000108 <li><a href="#vectorops">Vector Operations</a>
109 <ol>
110 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
111 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
112 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000113 </ol>
114 </li>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000115 <li><a href="#aggregateops">Aggregate Operations</a>
116 <ol>
117 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
118 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
119 </ol>
120 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000121 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000122 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000123 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
124 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
125 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000126 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
127 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
128 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000129 </ol>
130 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000131 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000132 <ol>
133 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
134 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
135 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
136 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
137 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000138 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
139 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
140 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
141 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000142 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
143 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000144 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000145 </ol>
Chris Lattner00950542001-06-06 20:29:01 +0000146 <li><a href="#otherops">Other Operations</a>
147 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000148 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
149 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begemanac80ade2008-05-12 19:01:56 +0000150 <li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
151 <li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000152 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000153 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000154 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000155 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000156 <li><a href="#i_getresult">'<tt>getresult</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000157 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000158 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000159 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000160 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000161 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000162 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000163 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
164 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000165 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
166 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
167 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000168 </ol>
169 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000170 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
171 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000172 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
173 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
174 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000175 </ol>
176 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000177 <li><a href="#int_codegen">Code Generator Intrinsics</a>
178 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000179 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
180 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
181 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
182 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
183 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
184 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
185 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000186 </ol>
187 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000188 <li><a href="#int_libc">Standard C Library Intrinsics</a>
189 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000190 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
191 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
192 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
193 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
194 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000195 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
196 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
197 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000198 </ol>
199 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000200 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000201 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000202 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000203 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
204 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
205 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencerf86037f2007-04-11 23:23:49 +0000206 <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
207 <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000208 </ol>
209 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000210 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000211 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000212 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000213 <ol>
214 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000215 </ol>
216 </li>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000217 <li><a href="#int_atomics">Atomic intrinsics</a>
218 <ol>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000219 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
Mon P Wang28873102008-06-25 08:15:39 +0000220 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000221 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
Mon P Wang28873102008-06-25 08:15:39 +0000222 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
223 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
224 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
225 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
226 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
227 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
228 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
229 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
230 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
231 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000232 </ol>
233 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000234 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000235 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000236 <li><a href="#int_var_annotation">
Tanya Lattner91d0b882007-09-22 00:01:26 +0000237 <tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000238 <li><a href="#int_annotation">
Tanya Lattner91d0b882007-09-22 00:01:26 +0000239 <tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000240 <li><a href="#int_trap">
241 <tt>llvm.trap</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000242 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000243 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000244 </ol>
245 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000246</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000247
248<div class="doc_author">
249 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
250 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000251</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000252
Chris Lattner00950542001-06-06 20:29:01 +0000253<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000254<div class="doc_section"> <a name="abstract">Abstract </a></div>
255<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000256
Misha Brukman9d0919f2003-11-08 01:05:38 +0000257<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000258<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling837f39b2008-08-05 22:29:16 +0000259LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattnerd3eda892008-08-05 18:29:16 +0000260type safety, low-level operations, flexibility, and the capability of
261representing 'all' high-level languages cleanly. It is the common code
Chris Lattner261efe92003-11-25 01:02:51 +0000262representation used throughout all phases of the LLVM compilation
263strategy.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000264</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000265
Chris Lattner00950542001-06-06 20:29:01 +0000266<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000267<div class="doc_section"> <a name="introduction">Introduction</a> </div>
268<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000269
Misha Brukman9d0919f2003-11-08 01:05:38 +0000270<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000271
Chris Lattner261efe92003-11-25 01:02:51 +0000272<p>The LLVM code representation is designed to be used in three
Gabor Greif04367bf2007-07-06 22:07:22 +0000273different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner261efe92003-11-25 01:02:51 +0000274representation (suitable for fast loading by a Just-In-Time compiler),
275and as a human readable assembly language representation. This allows
276LLVM to provide a powerful intermediate representation for efficient
277compiler transformations and analysis, while providing a natural means
278to debug and visualize the transformations. The three different forms
279of LLVM are all equivalent. This document describes the human readable
280representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000281
John Criswellc1f786c2005-05-13 22:25:59 +0000282<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner261efe92003-11-25 01:02:51 +0000283while being expressive, typed, and extensible at the same time. It
284aims to be a "universal IR" of sorts, by being at a low enough level
285that high-level ideas may be cleanly mapped to it (similar to how
286microprocessors are "universal IR's", allowing many source languages to
287be mapped to them). By providing type information, LLVM can be used as
288the target of optimizations: for example, through pointer analysis, it
289can be proven that a C automatic variable is never accessed outside of
290the current function... allowing it to be promoted to a simple SSA
291value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000292
Misha Brukman9d0919f2003-11-08 01:05:38 +0000293</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000294
Chris Lattner00950542001-06-06 20:29:01 +0000295<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000296<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000297
Misha Brukman9d0919f2003-11-08 01:05:38 +0000298<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000299
Chris Lattner261efe92003-11-25 01:02:51 +0000300<p>It is important to note that this document describes 'well formed'
301LLVM assembly language. There is a difference between what the parser
302accepts and what is considered 'well formed'. For example, the
303following instruction is syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000304
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000305<div class="doc_code">
Chris Lattnerd7923912004-05-23 21:06:01 +0000306<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000307%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000308</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000309</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000310
Chris Lattner261efe92003-11-25 01:02:51 +0000311<p>...because the definition of <tt>%x</tt> does not dominate all of
312its uses. The LLVM infrastructure provides a verification pass that may
313be used to verify that an LLVM module is well formed. This pass is
John Criswellc1f786c2005-05-13 22:25:59 +0000314automatically run by the parser after parsing input assembly and by
Gabor Greif04367bf2007-07-06 22:07:22 +0000315the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner261efe92003-11-25 01:02:51 +0000316by the verifier pass indicate bugs in transformation passes or input to
317the parser.</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000318</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000319
Chris Lattnercc689392007-10-03 17:34:29 +0000320<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000321
Chris Lattner00950542001-06-06 20:29:01 +0000322<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000323<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner00950542001-06-06 20:29:01 +0000324<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000325
Misha Brukman9d0919f2003-11-08 01:05:38 +0000326<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000327
Reid Spencer2c452282007-08-07 14:34:28 +0000328 <p>LLVM identifiers come in two basic types: global and local. Global
329 identifiers (functions, global variables) begin with the @ character. Local
330 identifiers (register names, types) begin with the % character. Additionally,
331 there are three different formats for identifiers, for different purposes:
Chris Lattnerd7923912004-05-23 21:06:01 +0000332
Chris Lattner00950542001-06-06 20:29:01 +0000333<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000334 <li>Named values are represented as a string of characters with their prefix.
335 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
336 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnere5d947b2004-12-09 16:36:40 +0000337 Identifiers which require other characters in their names can be surrounded
Reid Spencer2c452282007-08-07 14:34:28 +0000338 with quotes. In this way, anything except a <tt>&quot;</tt> character can
339 be used in a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000340
Reid Spencer2c452282007-08-07 14:34:28 +0000341 <li>Unnamed values are represented as an unsigned numeric value with their
342 prefix. For example, %12, @2, %44.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000343
Reid Spencercc16dc32004-12-09 18:02:53 +0000344 <li>Constants, which are described in a <a href="#constants">section about
345 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000346</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000347
Reid Spencer2c452282007-08-07 14:34:28 +0000348<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnere5d947b2004-12-09 16:36:40 +0000349don't need to worry about name clashes with reserved words, and the set of
350reserved words may be expanded in the future without penalty. Additionally,
351unnamed identifiers allow a compiler to quickly come up with a temporary
352variable without having to avoid symbol table conflicts.</p>
353
Chris Lattner261efe92003-11-25 01:02:51 +0000354<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5c0ef472006-11-11 23:08:07 +0000355languages. There are keywords for different opcodes
356('<tt><a href="#i_add">add</a></tt>',
357 '<tt><a href="#i_bitcast">bitcast</a></tt>',
358 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names ('<tt><a
Reid Spencerca86e162006-12-31 07:07:53 +0000359href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnere5d947b2004-12-09 16:36:40 +0000360and others. These reserved words cannot conflict with variable names, because
Reid Spencer2c452282007-08-07 14:34:28 +0000361none of them start with a prefix character ('%' or '@').</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000362
363<p>Here is an example of LLVM code to multiply the integer variable
364'<tt>%X</tt>' by 8:</p>
365
Misha Brukman9d0919f2003-11-08 01:05:38 +0000366<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000367
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000368<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000369<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000370%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000371</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000372</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000373
Misha Brukman9d0919f2003-11-08 01:05:38 +0000374<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000375
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000376<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000377<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000378%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000379</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000380</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000381
Misha Brukman9d0919f2003-11-08 01:05:38 +0000382<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000383
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000384<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000385<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000386<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
387<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
388%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000389</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000390</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000391
Chris Lattner261efe92003-11-25 01:02:51 +0000392<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
393important lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000394
Chris Lattner00950542001-06-06 20:29:01 +0000395<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000396
397 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
398 line.</li>
399
400 <li>Unnamed temporaries are created when the result of a computation is not
401 assigned to a named value.</li>
402
Misha Brukman9d0919f2003-11-08 01:05:38 +0000403 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000404
Misha Brukman9d0919f2003-11-08 01:05:38 +0000405</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000406
John Criswelle4c57cc2005-05-12 16:52:32 +0000407<p>...and it also shows a convention that we follow in this document. When
Chris Lattnere5d947b2004-12-09 16:36:40 +0000408demonstrating instructions, we will follow an instruction with a comment that
409defines the type and name of value produced. Comments are shown in italic
410text.</p>
411
Misha Brukman9d0919f2003-11-08 01:05:38 +0000412</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000413
414<!-- *********************************************************************** -->
415<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
416<!-- *********************************************************************** -->
417
418<!-- ======================================================================= -->
419<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
420</div>
421
422<div class="doc_text">
423
424<p>LLVM programs are composed of "Module"s, each of which is a
425translation unit of the input programs. Each module consists of
426functions, global variables, and symbol table entries. Modules may be
427combined together with the LLVM linker, which merges function (and
428global variable) definitions, resolves forward declarations, and merges
429symbol table entries. Here is an example of the "hello world" module:</p>
430
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000431<div class="doc_code">
Chris Lattnerfa730212004-12-09 16:11:40 +0000432<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000433<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
434 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 +0000435
436<i>; External declaration of the puts function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000437<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000438
439<i>; Definition of main function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000440define i32 @main() { <i>; i32()* </i>
Reid Spencerca86e162006-12-31 07:07:53 +0000441 <i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000442 %cast210 = <a
Chris Lattner6c0955b2007-06-12 17:01:15 +0000443 href="#i_getelementptr">getelementptr</a> [13 x i8 ]* @.LC0, i64 0, i64 0 <i>; i8 *</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000444
445 <i>; Call puts function to write out the string to stdout...</i>
446 <a
Chris Lattnera89e5f12007-06-12 17:00:26 +0000447 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000448 <a
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000449 href="#i_ret">ret</a> i32 0<br>}<br>
450</pre>
451</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000452
453<p>This example is made up of a <a href="#globalvars">global variable</a>
454named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
455function, and a <a href="#functionstructure">function definition</a>
456for "<tt>main</tt>".</p>
457
Chris Lattnere5d947b2004-12-09 16:36:40 +0000458<p>In general, a module is made up of a list of global values,
459where both functions and global variables are global values. Global values are
460represented by a pointer to a memory location (in this case, a pointer to an
461array of char, and a pointer to a function), and have one of the following <a
462href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000463
Chris Lattnere5d947b2004-12-09 16:36:40 +0000464</div>
465
466<!-- ======================================================================= -->
467<div class="doc_subsection">
468 <a name="linkage">Linkage Types</a>
469</div>
470
471<div class="doc_text">
472
473<p>
474All Global Variables and Functions have one of the following types of linkage:
475</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000476
477<dl>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000478
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000479 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000480
481 <dd>Global values with internal linkage are only directly accessible by
482 objects in the current module. In particular, linking code into a module with
483 an internal global value may cause the internal to be renamed as necessary to
484 avoid collisions. Because the symbol is internal to the module, all
485 references can be updated. This corresponds to the notion of the
Chris Lattner4887bd82007-01-14 06:51:48 +0000486 '<tt>static</tt>' keyword in C.
Chris Lattnerfa730212004-12-09 16:11:40 +0000487 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000488
Chris Lattnerfa730212004-12-09 16:11:40 +0000489 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000490
Chris Lattner4887bd82007-01-14 06:51:48 +0000491 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
492 the same name when linkage occurs. This is typically used to implement
493 inline functions, templates, or other code which must be generated in each
494 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
495 allowed to be discarded.
Chris Lattnerfa730212004-12-09 16:11:40 +0000496 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000497
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000498 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
499
500 <dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
501 linkage, except that unreferenced <tt>common</tt> globals may not be
502 discarded. This is used for globals that may be emitted in multiple
503 translation units, but that are not guaranteed to be emitted into every
504 translation unit that uses them. One example of this is tentative
505 definitions in C, such as "<tt>int X;</tt>" at global scope.
506 </dd>
507
Chris Lattnerfa730212004-12-09 16:11:40 +0000508 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000509
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000510 <dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
511 that some targets may choose to emit different assembly sequences for them
512 for target-dependent reasons. This is used for globals that are declared
513 "weak" in C source code.
Chris Lattnerfa730212004-12-09 16:11:40 +0000514 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000515
Chris Lattnerfa730212004-12-09 16:11:40 +0000516 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000517
518 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
519 pointer to array type. When two global variables with appending linkage are
520 linked together, the two global arrays are appended together. This is the
521 LLVM, typesafe, equivalent of having the system linker append together
522 "sections" with identical names when .o files are linked.
Chris Lattnerfa730212004-12-09 16:11:40 +0000523 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000524
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000525 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000526 <dd>The semantics of this linkage follow the ELF object file model: the
527 symbol is weak until linked, if not linked, the symbol becomes null instead
528 of being an undefined reference.
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000529 </dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000530
Chris Lattnerfa730212004-12-09 16:11:40 +0000531 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000532
533 <dd>If none of the above identifiers are used, the global is externally
534 visible, meaning that it participates in linkage and can be used to resolve
535 external symbol references.
Chris Lattnerfa730212004-12-09 16:11:40 +0000536 </dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000537</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000538
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000539 <p>
540 The next two types of linkage are targeted for Microsoft Windows platform
541 only. They are designed to support importing (exporting) symbols from (to)
Chris Lattnerd3eda892008-08-05 18:29:16 +0000542 DLLs (Dynamic Link Libraries).
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000543 </p>
544
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000545 <dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000546 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
547
548 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
549 or variable via a global pointer to a pointer that is set up by the DLL
550 exporting the symbol. On Microsoft Windows targets, the pointer name is
551 formed by combining <code>_imp__</code> and the function or variable name.
552 </dd>
553
554 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
555
556 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
557 pointer to a pointer in a DLL, so that it can be referenced with the
558 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
559 name is formed by combining <code>_imp__</code> and the function or variable
560 name.
561 </dd>
562
Chris Lattnerfa730212004-12-09 16:11:40 +0000563</dl>
564
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000565<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
Chris Lattnerfa730212004-12-09 16:11:40 +0000566variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
567variable and was linked with this one, one of the two would be renamed,
568preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
569external (i.e., lacking any linkage declarations), they are accessible
Reid Spencerac8d2762007-01-05 00:59:10 +0000570outside of the current module.</p>
571<p>It is illegal for a function <i>declaration</i>
572to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000573or <tt>extern_weak</tt>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000574<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
575linkages.
Chris Lattnerfa730212004-12-09 16:11:40 +0000576</div>
577
578<!-- ======================================================================= -->
579<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000580 <a name="callingconv">Calling Conventions</a>
581</div>
582
583<div class="doc_text">
584
585<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
586and <a href="#i_invoke">invokes</a> can all have an optional calling convention
587specified for the call. The calling convention of any pair of dynamic
588caller/callee must match, or the behavior of the program is undefined. The
589following calling conventions are supported by LLVM, and more may be added in
590the future:</p>
591
592<dl>
593 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
594
595 <dd>This calling convention (the default if no other calling convention is
596 specified) matches the target C calling conventions. This calling convention
John Criswelle4c57cc2005-05-12 16:52:32 +0000597 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencerc28d2bc2006-12-31 21:30:18 +0000598 prototype and implemented declaration of the function (as does normal C).
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000599 </dd>
600
601 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
602
603 <dd>This calling convention attempts to make calls as fast as possible
604 (e.g. by passing things in registers). This calling convention allows the
605 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattnerd3eda892008-08-05 18:29:16 +0000606 without having to conform to an externally specified ABI (Application Binary
607 Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer9097d142008-05-14 09:17:12 +0000608 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
609 supported. This calling convention does not support varargs and requires the
610 prototype of all callees to exactly match the prototype of the function
611 definition.
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000612 </dd>
613
614 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
615
616 <dd>This calling convention attempts to make code in the caller as efficient
617 as possible under the assumption that the call is not commonly executed. As
618 such, these calls often preserve all registers so that the call does not break
619 any live ranges in the caller side. This calling convention does not support
620 varargs and requires the prototype of all callees to exactly match the
621 prototype of the function definition.
622 </dd>
623
Chris Lattnercfe6b372005-05-07 01:46:40 +0000624 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000625
626 <dd>Any calling convention may be specified by number, allowing
627 target-specific calling conventions to be used. Target specific calling
628 conventions start at 64.
629 </dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000630</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000631
632<p>More calling conventions can be added/defined on an as-needed basis, to
633support pascal conventions or any other well-known target-independent
634convention.</p>
635
636</div>
637
638<!-- ======================================================================= -->
639<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000640 <a name="visibility">Visibility Styles</a>
641</div>
642
643<div class="doc_text">
644
645<p>
646All Global Variables and Functions have one of the following visibility styles:
647</p>
648
649<dl>
650 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
651
Chris Lattnerd3eda892008-08-05 18:29:16 +0000652 <dd>On targets that use the ELF object file format, default visibility means
653 that the declaration is visible to other
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000654 modules and, in shared libraries, means that the declared entity may be
655 overridden. On Darwin, default visibility means that the declaration is
656 visible to other modules. Default visibility corresponds to "external
657 linkage" in the language.
658 </dd>
659
660 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
661
662 <dd>Two declarations of an object with hidden visibility refer to the same
663 object if they are in the same shared object. Usually, hidden visibility
664 indicates that the symbol will not be placed into the dynamic symbol table,
665 so no other module (executable or shared library) can reference it
666 directly.
667 </dd>
668
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000669 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
670
671 <dd>On ELF, protected visibility indicates that the symbol will be placed in
672 the dynamic symbol table, but that references within the defining module will
673 bind to the local symbol. That is, the symbol cannot be overridden by another
674 module.
675 </dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000676</dl>
677
678</div>
679
680<!-- ======================================================================= -->
681<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000682 <a name="globalvars">Global Variables</a>
683</div>
684
685<div class="doc_text">
686
Chris Lattner3689a342005-02-12 19:30:21 +0000687<p>Global variables define regions of memory allocated at compilation time
Chris Lattner88f6c462005-11-12 00:45:07 +0000688instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000689an explicit section to be placed in, and may have an optional explicit alignment
690specified. A variable may be defined as "thread_local", which means that it
691will not be shared by threads (each thread will have a separated copy of the
692variable). A variable may be defined as a global "constant," which indicates
693that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner3689a342005-02-12 19:30:21 +0000694optimization, allowing the global data to be placed in the read-only section of
695an executable, etc). Note that variables that need runtime initialization
John Criswell0ec250c2005-10-24 16:17:18 +0000696cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000697
698<p>
699LLVM explicitly allows <em>declarations</em> of global variables to be marked
700constant, even if the final definition of the global is not. This capability
701can be used to enable slightly better optimization of the program, but requires
702the language definition to guarantee that optimizations based on the
703'constantness' are valid for the translation units that do not include the
704definition.
705</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000706
707<p>As SSA values, global variables define pointer values that are in
708scope (i.e. they dominate) all basic blocks in the program. Global
709variables always define a pointer to their "content" type because they
710describe a region of memory, and all memory objects in LLVM are
711accessed through pointers.</p>
712
Christopher Lamb284d9922007-12-11 09:31:00 +0000713<p>A global variable may be declared to reside in a target-specifc numbered
714address space. For targets that support them, address spaces may affect how
715optimizations are performed and/or what target instructions are used to access
Christopher Lambd49e18d2007-12-12 08:44:39 +0000716the variable. The default address space is zero. The address space qualifier
717must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000718
Chris Lattner88f6c462005-11-12 00:45:07 +0000719<p>LLVM allows an explicit section to be specified for globals. If the target
720supports it, it will emit globals to the section specified.</p>
721
Chris Lattner2cbdc452005-11-06 08:02:57 +0000722<p>An explicit alignment may be specified for a global. If not present, or if
723the alignment is set to zero, the alignment of the global is set by the target
724to whatever it feels convenient. If an explicit alignment is specified, the
725global is forced to have at least that much alignment. All alignments must be
726a power of 2.</p>
727
Christopher Lamb284d9922007-12-11 09:31:00 +0000728<p>For example, the following defines a global in a numbered address space with
729an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000730
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000731<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000732<pre>
Christopher Lamb284d9922007-12-11 09:31:00 +0000733@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000734</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000735</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000736
Chris Lattnerfa730212004-12-09 16:11:40 +0000737</div>
738
739
740<!-- ======================================================================= -->
741<div class="doc_subsection">
742 <a name="functionstructure">Functions</a>
743</div>
744
745<div class="doc_text">
746
Reid Spencerca86e162006-12-31 07:07:53 +0000747<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
748an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000749<a href="#visibility">visibility style</a>, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000750<a href="#callingconv">calling convention</a>, a return type, an optional
751<a href="#paramattrs">parameter attribute</a> for the return type, a function
752name, a (possibly empty) argument list (each with optional
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000753<a href="#paramattrs">parameter attributes</a>), an optional section, an
Devang Patelf8b94812008-09-04 23:05:13 +0000754optional alignment, an optional <a href="#gc">garbage collector name</a>,
755an optional <a href="#notes">function notes</a>, an
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000756opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000757
758LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
759optional <a href="#linkage">linkage type</a>, an optional
760<a href="#visibility">visibility style</a>, an optional
761<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000762<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000763name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksene754abe2007-12-10 03:30:21 +0000764<a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000765
Chris Lattnerd3eda892008-08-05 18:29:16 +0000766<p>A function definition contains a list of basic blocks, forming the CFG
767(Control Flow Graph) for
Chris Lattnerfa730212004-12-09 16:11:40 +0000768the function. Each basic block may optionally start with a label (giving the
769basic block a symbol table entry), contains a list of instructions, and ends
770with a <a href="#terminators">terminator</a> instruction (such as a branch or
771function return).</p>
772
Chris Lattner4a3c9012007-06-08 16:52:14 +0000773<p>The first basic block in a function is special in two ways: it is immediately
Chris Lattnerfa730212004-12-09 16:11:40 +0000774executed on entrance to the function, and it is not allowed to have predecessor
775basic blocks (i.e. there can not be any branches to the entry block of a
776function). Because the block can have no predecessors, it also cannot have any
777<a href="#i_phi">PHI nodes</a>.</p>
778
Chris Lattner88f6c462005-11-12 00:45:07 +0000779<p>LLVM allows an explicit section to be specified for functions. If the target
780supports it, it will emit functions to the section specified.</p>
781
Chris Lattner2cbdc452005-11-06 08:02:57 +0000782<p>An explicit alignment may be specified for a function. If not present, or if
783the alignment is set to zero, the alignment of the function is set by the target
784to whatever it feels convenient. If an explicit alignment is specified, the
785function is forced to have at least that much alignment. All alignments must be
786a power of 2.</p>
787
Chris Lattnerfa730212004-12-09 16:11:40 +0000788</div>
789
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000790
791<!-- ======================================================================= -->
792<div class="doc_subsection">
793 <a name="aliasstructure">Aliases</a>
794</div>
795<div class="doc_text">
796 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov726d45c2008-03-22 08:36:14 +0000797 function, global variable, another alias or bitcast of global value). Aliases
798 may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000799 optional <a href="#visibility">visibility style</a>.</p>
800
801 <h5>Syntax:</h5>
802
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000803<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000804<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000805@&lt;Name&gt; = [Linkage] [Visibility] alias &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000806</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000807</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000808
809</div>
810
811
812
Chris Lattner4e9aba72006-01-23 23:23:47 +0000813<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000814<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
815<div class="doc_text">
816 <p>The return type and each parameter of a function type may have a set of
817 <i>parameter attributes</i> associated with them. Parameter attributes are
818 used to communicate additional information about the result or parameters of
Duncan Sandsdc024672007-11-27 13:23:08 +0000819 a function. Parameter attributes are considered to be part of the function,
820 not of the function type, so functions with different parameter attributes
821 can have the same function type.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000822
Reid Spencer950e9f82007-01-15 18:27:39 +0000823 <p>Parameter attributes are simple keywords that follow the type specified. If
824 multiple parameter attributes are needed, they are space separated. For
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000825 example:</p>
826
827<div class="doc_code">
828<pre>
Duncan Sandsdc024672007-11-27 13:23:08 +0000829declare i32 @printf(i8* noalias , ...) nounwind
830declare i32 @atoi(i8*) nounwind readonly
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000831</pre>
832</div>
833
Duncan Sandsdc024672007-11-27 13:23:08 +0000834 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
835 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000836
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000837 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000838 <dl>
Reid Spencer9445e9a2007-07-19 23:13:04 +0000839 <dt><tt>zeroext</tt></dt>
Reid Spencerca86e162006-12-31 07:07:53 +0000840 <dd>This indicates that the parameter should be zero extended just before
841 a call to this function.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000842
Reid Spencer9445e9a2007-07-19 23:13:04 +0000843 <dt><tt>signext</tt></dt>
Reid Spencerca86e162006-12-31 07:07:53 +0000844 <dd>This indicates that the parameter should be sign extended just before
845 a call to this function.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000846
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000847 <dt><tt>inreg</tt></dt>
848 <dd>This indicates that the parameter should be placed in register (if
Anton Korobeynikov66a8c8c2007-01-28 15:27:21 +0000849 possible) during assembling function call. Support for this attribute is
850 target-specific</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000851
852 <dt><tt>byval</tt></dt>
Chris Lattner0747baa2008-01-15 04:34:22 +0000853 <dd>This indicates that the pointer parameter should really be passed by
854 value to the function. The attribute implies that a hidden copy of the
855 pointee is made between the caller and the callee, so the callee is unable
Chris Lattnerebec6782008-08-05 18:21:08 +0000856 to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner0747baa2008-01-15 04:34:22 +0000857 pointer arguments. It is generally used to pass structs and arrays by
858 value, but is also valid on scalars (even though this is silly).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000859
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000860 <dt><tt>sret</tt></dt>
Duncan Sandse26dec62008-02-18 04:19:38 +0000861 <dd>This indicates that the pointer parameter specifies the address of a
862 structure that is the return value of the function in the source program.
Duncan Sandsb7f0c082008-03-17 12:17:41 +0000863 Loads and stores to the structure are assumed not to trap.
Duncan Sandse26dec62008-02-18 04:19:38 +0000864 May only be applied to the first parameter.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000865
Zhou Shengfebca342007-06-05 05:28:26 +0000866 <dt><tt>noalias</tt></dt>
Owen Anderson117bbd32008-02-18 04:09:01 +0000867 <dd>This indicates that the parameter does not alias any global or any other
868 parameter. The caller is responsible for ensuring that this is the case,
869 usually by placing the value in a stack allocation.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000870
Reid Spencer2dc52012007-03-22 02:18:56 +0000871 <dt><tt>noreturn</tt></dt>
872 <dd>This function attribute indicates that the function never returns. This
873 indicates to LLVM that every call to this function should be treated as if
874 an <tt>unreachable</tt> instruction immediately followed the call.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000875
Reid Spencer67606122007-03-22 02:02:11 +0000876 <dt><tt>nounwind</tt></dt>
Duncan Sandsb7f0c082008-03-17 12:17:41 +0000877 <dd>This function attribute indicates that no exceptions unwind out of the
878 function. Usually this is because the function makes no use of exceptions,
879 but it may also be that the function catches any exceptions thrown when
880 executing it.</dd>
881
Duncan Sands50f19f52007-07-27 19:57:41 +0000882 <dt><tt>nest</tt></dt>
Duncan Sands0789b8b2008-07-08 09:27:25 +0000883 <dd>This indicates that the pointer parameter can be excised using the
Duncan Sands50f19f52007-07-27 19:57:41 +0000884 <a href="#int_trampoline">trampoline intrinsics</a>.</dd>
Duncan Sandsed4a2f12007-11-22 20:23:04 +0000885 <dt><tt>readonly</tt></dt>
Duncan Sandsf04d5842007-11-14 21:14:02 +0000886 <dd>This function attribute indicates that the function has no side-effects
Duncan Sandsed4a2f12007-11-22 20:23:04 +0000887 except for producing a return value or throwing an exception. The value
888 returned must only depend on the function arguments and/or global variables.
889 It may use values obtained by dereferencing pointers.</dd>
890 <dt><tt>readnone</tt></dt>
891 <dd>A <tt>readnone</tt> function has the same restrictions as a <tt>readonly</tt>
Duncan Sandsf04d5842007-11-14 21:14:02 +0000892 function, but in addition it is not allowed to dereference any pointer arguments
893 or global variables.
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000894 </dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000895
Reid Spencerca86e162006-12-31 07:07:53 +0000896</div>
897
898<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000899<div class="doc_subsection">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000900 <a name="gc">Garbage Collector Names</a>
901</div>
902
903<div class="doc_text">
904<p>Each function may specify a garbage collector name, which is simply a
905string.</p>
906
907<div class="doc_code"><pre
908>define void @f() gc "name" { ...</pre></div>
909
910<p>The compiler declares the supported values of <i>name</i>. Specifying a
911collector which will cause the compiler to alter its output in order to support
912the named garbage collection algorithm.</p>
913</div>
914
915<!-- ======================================================================= -->
916<div class="doc_subsection">
Devang Patelf8b94812008-09-04 23:05:13 +0000917 <a name="notes">Function Notes</a>
918</div>
919
920<div class="doc_text">
Devang Patelcdc06692008-09-04 23:10:26 +0000921<p>The function definition may list function notes which are used by
922various passes.</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000923
924<div class="doc_code">
925<pre>define void @f() notes(inline=Always) { ... }</pre>
926<pre>define void @f() notes(inline=Always,opt-size) { ... }</pre>
927<pre>define void @f() notes(inline=Never,opt-size) { ... }</pre>
928<pre>define void @f() notes(opt-size) { ... }</pre>
929</div>
930
931<p>
932<li>inline=Always
933<p>
934This note requests inliner to inline this function irrespective of
935inlining size threshold for this function.
936</p></li>
937<li>inline=Never
938<p>
939This note requests inliner to never inline this function in any situation.
940This note may not be used together with inline=Always note.
941</p></li>
942<li>opt-size
943<p>
944This note suggests optimization passes and code generator passes to make
945choices that help reduce code size.
946</p></li>
947<p>
948The notes that are not documented here are considered invalid notes.
949</div>
950
951<!-- ======================================================================= -->
952<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000953 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000954</div>
955
956<div class="doc_text">
957<p>
958Modules may contain "module-level inline asm" blocks, which corresponds to the
959GCC "file scope inline asm" blocks. These blocks are internally concatenated by
960LLVM and treated as a single unit, but may be separated in the .ll file if
961desired. The syntax is very simple:
962</p>
963
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000964<div class="doc_code">
965<pre>
966module asm "inline asm code goes here"
967module asm "more can go here"
968</pre>
969</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000970
971<p>The strings can contain any character by escaping non-printable characters.
972 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
973 for the number.
974</p>
975
976<p>
977 The inline asm code is simply printed to the machine code .s file when
978 assembly code is generated.
979</p>
980</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000981
Reid Spencerde151942007-02-19 23:54:10 +0000982<!-- ======================================================================= -->
983<div class="doc_subsection">
984 <a name="datalayout">Data Layout</a>
985</div>
986
987<div class="doc_text">
988<p>A module may specify a target specific data layout string that specifies how
Reid Spencerc8910842007-04-11 23:49:50 +0000989data is to be laid out in memory. The syntax for the data layout is simply:</p>
990<pre> target datalayout = "<i>layout specification</i>"</pre>
991<p>The <i>layout specification</i> consists of a list of specifications
992separated by the minus sign character ('-'). Each specification starts with a
993letter and may include other information after the letter to define some
994aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencerde151942007-02-19 23:54:10 +0000995<dl>
996 <dt><tt>E</tt></dt>
997 <dd>Specifies that the target lays out data in big-endian form. That is, the
998 bits with the most significance have the lowest address location.</dd>
999 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +00001000 <dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencerde151942007-02-19 23:54:10 +00001001 the bits with the least significance have the lowest address location.</dd>
1002 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1003 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
1004 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
1005 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
1006 too.</dd>
1007 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1008 <dd>This specifies the alignment for an integer type of a given bit
1009 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1010 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1011 <dd>This specifies the alignment for a vector type of a given bit
1012 <i>size</i>.</dd>
1013 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1014 <dd>This specifies the alignment for a floating point type of a given bit
1015 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1016 (double).</dd>
1017 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1018 <dd>This specifies the alignment for an aggregate type of a given bit
1019 <i>size</i>.</dd>
1020</dl>
1021<p>When constructing the data layout for a given target, LLVM starts with a
1022default set of specifications which are then (possibly) overriden by the
1023specifications in the <tt>datalayout</tt> keyword. The default specifications
1024are given in this list:</p>
1025<ul>
1026 <li><tt>E</tt> - big endian</li>
1027 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1028 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1029 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1030 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1031 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +00001032 <li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Reid Spencerde151942007-02-19 23:54:10 +00001033 alignment of 64-bits</li>
1034 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1035 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1036 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1037 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1038 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
1039</ul>
Chris Lattnerebec6782008-08-05 18:21:08 +00001040<p>When LLVM is determining the alignment for a given type, it uses the
Reid Spencerde151942007-02-19 23:54:10 +00001041following rules:
1042<ol>
1043 <li>If the type sought is an exact match for one of the specifications, that
1044 specification is used.</li>
1045 <li>If no match is found, and the type sought is an integer type, then the
1046 smallest integer type that is larger than the bitwidth of the sought type is
1047 used. If none of the specifications are larger than the bitwidth then the the
1048 largest integer type is used. For example, given the default specifications
1049 above, the i7 type will use the alignment of i8 (next largest) while both
1050 i65 and i256 will use the alignment of i64 (largest specified).</li>
1051 <li>If no match is found, and the type sought is a vector type, then the
1052 largest vector type that is smaller than the sought vector type will be used
1053 as a fall back. This happens because <128 x double> can be implemented in
1054 terms of 64 <2 x double>, for example.</li>
1055</ol>
1056</div>
Chris Lattnerfa730212004-12-09 16:11:40 +00001057
Chris Lattner00950542001-06-06 20:29:01 +00001058<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +00001059<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1060<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +00001061
Misha Brukman9d0919f2003-11-08 01:05:38 +00001062<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +00001063
Misha Brukman9d0919f2003-11-08 01:05:38 +00001064<p>The LLVM type system is one of the most important features of the
Chris Lattner261efe92003-11-25 01:02:51 +00001065intermediate representation. Being typed enables a number of
Chris Lattnerd3eda892008-08-05 18:29:16 +00001066optimizations to be performed on the intermediate representation directly,
1067without having to do
Chris Lattner261efe92003-11-25 01:02:51 +00001068extra analyses on the side before the transformation. A strong type
1069system makes it easier to read the generated code and enables novel
1070analyses and transformations that are not feasible to perform on normal
1071three address code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +00001072
1073</div>
1074
Chris Lattner00950542001-06-06 20:29:01 +00001075<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +00001076<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner261efe92003-11-25 01:02:51 +00001077Classifications</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +00001078<div class="doc_text">
Chris Lattner4f69f462008-01-04 04:32:38 +00001079<p>The types fall into a few useful
Chris Lattner261efe92003-11-25 01:02:51 +00001080classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +00001081
1082<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +00001083 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +00001084 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +00001085 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +00001086 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +00001087 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +00001088 </tr>
1089 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +00001090 <td><a href="#t_floating">floating point</a></td>
1091 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +00001092 </tr>
1093 <tr>
1094 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +00001095 <td><a href="#t_integer">integer</a>,
1096 <a href="#t_floating">floating point</a>,
1097 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +00001098 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +00001099 <a href="#t_struct">structure</a>,
1100 <a href="#t_array">array</a>,
Dan Gohmanade5faa2008-05-23 22:50:26 +00001101 <a href="#t_label">label</a>.
Reid Spencerca86e162006-12-31 07:07:53 +00001102 </td>
Chris Lattner261efe92003-11-25 01:02:51 +00001103 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +00001104 <tr>
1105 <td><a href="#t_primitive">primitive</a></td>
1106 <td><a href="#t_label">label</a>,
1107 <a href="#t_void">void</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +00001108 <a href="#t_floating">floating point</a>.</td>
1109 </tr>
1110 <tr>
1111 <td><a href="#t_derived">derived</a></td>
1112 <td><a href="#t_integer">integer</a>,
1113 <a href="#t_array">array</a>,
1114 <a href="#t_function">function</a>,
1115 <a href="#t_pointer">pointer</a>,
1116 <a href="#t_struct">structure</a>,
1117 <a href="#t_pstruct">packed structure</a>,
1118 <a href="#t_vector">vector</a>,
1119 <a href="#t_opaque">opaque</a>.
1120 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +00001121 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +00001122</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +00001123
Chris Lattner261efe92003-11-25 01:02:51 +00001124<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1125most important. Values of these types are the only ones which can be
1126produced by instructions, passed as arguments, or used as operands to
Dan Gohmanc4b49eb2008-05-23 21:53:15 +00001127instructions.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +00001128</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +00001129
Chris Lattner00950542001-06-06 20:29:01 +00001130<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +00001131<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner8f8c7b72008-01-04 04:34:14 +00001132
Chris Lattner4f69f462008-01-04 04:32:38 +00001133<div class="doc_text">
1134<p>The primitive types are the fundamental building blocks of the LLVM
1135system.</p>
1136
Chris Lattner8f8c7b72008-01-04 04:34:14 +00001137</div>
1138
Chris Lattner4f69f462008-01-04 04:32:38 +00001139<!-- _______________________________________________________________________ -->
1140<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1141
1142<div class="doc_text">
1143 <table>
1144 <tbody>
1145 <tr><th>Type</th><th>Description</th></tr>
1146 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1147 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1148 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1149 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1150 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1151 </tbody>
1152 </table>
1153</div>
1154
1155<!-- _______________________________________________________________________ -->
1156<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1157
1158<div class="doc_text">
1159<h5>Overview:</h5>
1160<p>The void type does not represent any value and has no size.</p>
1161
1162<h5>Syntax:</h5>
1163
1164<pre>
1165 void
1166</pre>
1167</div>
1168
1169<!-- _______________________________________________________________________ -->
1170<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1171
1172<div class="doc_text">
1173<h5>Overview:</h5>
1174<p>The label type represents code labels.</p>
1175
1176<h5>Syntax:</h5>
1177
1178<pre>
1179 label
1180</pre>
1181</div>
1182
1183
1184<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +00001185<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +00001186
Misha Brukman9d0919f2003-11-08 01:05:38 +00001187<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +00001188
Chris Lattner261efe92003-11-25 01:02:51 +00001189<p>The real power in LLVM comes from the derived types in the system.
1190This is what allows a programmer to represent arrays, functions,
1191pointers, and other useful types. Note that these derived types may be
1192recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +00001193
Misha Brukman9d0919f2003-11-08 01:05:38 +00001194</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +00001195
Chris Lattner00950542001-06-06 20:29:01 +00001196<!-- _______________________________________________________________________ -->
Reid Spencer2b916312007-05-16 18:44:01 +00001197<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1198
1199<div class="doc_text">
1200
1201<h5>Overview:</h5>
1202<p>The integer type is a very simple derived type that simply specifies an
1203arbitrary bit width for the integer type desired. Any bit width from 1 bit to
12042^23-1 (about 8 million) can be specified.</p>
1205
1206<h5>Syntax:</h5>
1207
1208<pre>
1209 iN
1210</pre>
1211
1212<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1213value.</p>
1214
1215<h5>Examples:</h5>
1216<table class="layout">
Chris Lattnerb9488a62007-12-18 06:18:21 +00001217 <tbody>
1218 <tr>
1219 <td><tt>i1</tt></td>
1220 <td>a single-bit integer.</td>
1221 </tr><tr>
1222 <td><tt>i32</tt></td>
1223 <td>a 32-bit integer.</td>
1224 </tr><tr>
1225 <td><tt>i1942652</tt></td>
1226 <td>a really big integer of over 1 million bits.</td>
Reid Spencer2b916312007-05-16 18:44:01 +00001227 </tr>
Chris Lattnerb9488a62007-12-18 06:18:21 +00001228 </tbody>
Reid Spencer2b916312007-05-16 18:44:01 +00001229</table>
Bill Wendling2f7a8b02007-05-29 09:04:49 +00001230</div>
Reid Spencer2b916312007-05-16 18:44:01 +00001231
1232<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +00001233<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +00001234
Misha Brukman9d0919f2003-11-08 01:05:38 +00001235<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +00001236
Chris Lattner00950542001-06-06 20:29:01 +00001237<h5>Overview:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +00001238
Misha Brukman9d0919f2003-11-08 01:05:38 +00001239<p>The array type is a very simple derived type that arranges elements
Chris Lattner261efe92003-11-25 01:02:51 +00001240sequentially in memory. The array type requires a size (number of
1241elements) and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +00001242
Chris Lattner7faa8832002-04-14 06:13:44 +00001243<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +00001244
1245<pre>
1246 [&lt;# elements&gt; x &lt;elementtype&gt;]
1247</pre>
1248
John Criswelle4c57cc2005-05-12 16:52:32 +00001249<p>The number of elements is a constant integer value; elementtype may
Chris Lattner261efe92003-11-25 01:02:51 +00001250be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +00001251
Chris Lattner7faa8832002-04-14 06:13:44 +00001252<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +00001253<table class="layout">
1254 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +00001255 <td class="left"><tt>[40 x i32]</tt></td>
1256 <td class="left">Array of 40 32-bit integer values.</td>
1257 </tr>
1258 <tr class="layout">
1259 <td class="left"><tt>[41 x i32]</tt></td>
1260 <td class="left">Array of 41 32-bit integer values.</td>
1261 </tr>
1262 <tr class="layout">
1263 <td class="left"><tt>[4 x i8]</tt></td>
1264 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +00001265 </tr>
Chris Lattner00950542001-06-06 20:29:01 +00001266</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +00001267<p>Here are some examples of multidimensional arrays:</p>
1268<table class="layout">
1269 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +00001270 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1271 <td class="left">3x4 array of 32-bit integer values.</td>
1272 </tr>
1273 <tr class="layout">
1274 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1275 <td class="left">12x10 array of single precision floating point values.</td>
1276 </tr>
1277 <tr class="layout">
1278 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1279 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +00001280 </tr>
1281</table>
Chris Lattnere67a9512005-06-24 17:22:57 +00001282
John Criswell0ec250c2005-10-24 16:17:18 +00001283<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1284length array. Normally, accesses past the end of an array are undefined in
Chris Lattnere67a9512005-06-24 17:22:57 +00001285LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1286As a special case, however, zero length arrays are recognized to be variable
1287length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerca86e162006-12-31 07:07:53 +00001288type "{ i32, [0 x float]}", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +00001289
Misha Brukman9d0919f2003-11-08 01:05:38 +00001290</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +00001291
Chris Lattner00950542001-06-06 20:29:01 +00001292<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +00001293<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +00001294<div class="doc_text">
Chris Lattnerf4cde4e2008-04-23 04:59:35 +00001295
Chris Lattner00950542001-06-06 20:29:01 +00001296<h5>Overview:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +00001297
Chris Lattner261efe92003-11-25 01:02:51 +00001298<p>The function type can be thought of as a function signature. It
Devang Patela582f402008-03-24 05:35:41 +00001299consists of a return type and a list of formal parameter types. The
Chris Lattnerf4cde4e2008-04-23 04:59:35 +00001300return type of a function type is a scalar type, a void type, or a struct type.
Devang Patel7a3ad1a2008-03-24 20:52:42 +00001301If the return type is a struct type then all struct elements must be of first
Chris Lattnerf4cde4e2008-04-23 04:59:35 +00001302class types, and the struct must have at least one element.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +00001303
Chris Lattner00950542001-06-06 20:29:01 +00001304<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +00001305
1306<pre>
1307 &lt;returntype list&gt; (&lt;parameter list&gt;)
1308</pre>
1309
John Criswell0ec250c2005-10-24 16:17:18 +00001310<p>...where '<tt>&lt;parameter list&gt;</tt>' is a comma-separated list of type
Misha Brukmanc24b7582004-08-12 20:16:08 +00001311specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner27f71f22003-09-03 00:41:47 +00001312which indicates that the function takes a variable number of arguments.
1313Variable argument functions can access their arguments with the <a
Devang Patelc3fc6df2008-03-10 20:49:15 +00001314 href="#int_varargs">variable argument handling intrinsic</a> functions.
1315'<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1316<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +00001317
Chris Lattner00950542001-06-06 20:29:01 +00001318<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +00001319<table class="layout">
1320 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +00001321 <td class="left"><tt>i32 (i32)</tt></td>
1322 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +00001323 </td>
Reid Spencer92f82302006-12-31 07:18:34 +00001324 </tr><tr class="layout">
Reid Spencer9445e9a2007-07-19 23:13:04 +00001325 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +00001326 </tt></td>
Reid Spencer92f82302006-12-31 07:18:34 +00001327 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1328 an <tt>i16</tt> that should be sign extended and a
Reid Spencerca86e162006-12-31 07:07:53 +00001329 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer92f82302006-12-31 07:18:34 +00001330 <tt>float</tt>.
1331 </td>
1332 </tr><tr class="layout">
1333 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1334 <td class="left">A vararg function that takes at least one
Reid Spencera5173382007-01-04 16:43:23 +00001335 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer92f82302006-12-31 07:18:34 +00001336 which returns an integer. This is the signature for <tt>printf</tt> in
1337 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +00001338 </td>
Devang Patela582f402008-03-24 05:35:41 +00001339 </tr><tr class="layout">
1340 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Devang Patel3a5bff82008-03-24 18:10:52 +00001341 <td class="left">A function taking an <tt>i32></tt>, returning two
1342 <tt> i32 </tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patela582f402008-03-24 05:35:41 +00001343 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +00001344 </tr>
Chris Lattner00950542001-06-06 20:29:01 +00001345</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +00001346
Misha Brukman9d0919f2003-11-08 01:05:38 +00001347</div>
Chris Lattner00950542001-06-06 20:29:01 +00001348<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +00001349<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +00001350<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +00001351<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +00001352<p>The structure type is used to represent a collection of data members
1353together in memory. The packing of the field types is defined to match
1354the ABI of the underlying processor. The elements of a structure may
1355be any type that has a size.</p>
1356<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1357and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1358field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1359instruction.</p>
Chris Lattner00950542001-06-06 20:29:01 +00001360<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +00001361<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner00950542001-06-06 20:29:01 +00001362<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +00001363<table class="layout">
1364 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +00001365 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1366 <td class="left">A triple of three <tt>i32</tt> values</td>
1367 </tr><tr class="layout">
1368 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1369 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1370 second element is a <a href="#t_pointer">pointer</a> to a
1371 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1372 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +00001373 </tr>
Chris Lattner00950542001-06-06 20:29:01 +00001374</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +00001375</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +00001376
Chris Lattner00950542001-06-06 20:29:01 +00001377<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +00001378<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1379</div>
1380<div class="doc_text">
1381<h5>Overview:</h5>
1382<p>The packed structure type is used to represent a collection of data members
1383together in memory. There is no padding between fields. Further, the alignment
1384of a packed structure is 1 byte. The elements of a packed structure may
1385be any type that has a size.</p>
1386<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1387and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1388field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1389instruction.</p>
1390<h5>Syntax:</h5>
1391<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1392<h5>Examples:</h5>
1393<table class="layout">
1394 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +00001395 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1396 <td class="left">A triple of three <tt>i32</tt> values</td>
1397 </tr><tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +00001398 <td class="left"><tt>&lt; { float, i32 (i32)* } &gt;</tt></td>
Jeff Cohen6f1cc772007-04-22 01:17:39 +00001399 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1400 second element is a <a href="#t_pointer">pointer</a> to a
1401 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1402 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +00001403 </tr>
1404</table>
1405</div>
1406
1407<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +00001408<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +00001409<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +00001410<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +00001411<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb284d9922007-12-11 09:31:00 +00001412reference to another object, which must live in memory. Pointer types may have
1413an optional address space attribute defining the target-specific numbered
1414address space where the pointed-to object resides. The default address space is
1415zero.</p>
Chris Lattner7faa8832002-04-14 06:13:44 +00001416<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +00001417<pre> &lt;type&gt; *<br></pre>
Chris Lattner7faa8832002-04-14 06:13:44 +00001418<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +00001419<table class="layout">
1420 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +00001421 <td class="left"><tt>[4x i32]*</tt></td>
1422 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1423 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1424 </tr>
1425 <tr class="layout">
1426 <td class="left"><tt>i32 (i32 *) *</tt></td>
1427 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +00001428 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +00001429 <tt>i32</tt>.</td>
1430 </tr>
1431 <tr class="layout">
1432 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1433 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1434 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +00001435 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +00001436</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +00001437</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +00001438
Chris Lattnera58561b2004-08-12 19:12:28 +00001439<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +00001440<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +00001441<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +00001442
Chris Lattnera58561b2004-08-12 19:12:28 +00001443<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +00001444
Reid Spencer485bad12007-02-15 03:07:05 +00001445<p>A vector type is a simple derived type that represents a vector
1446of elements. Vector types are used when multiple primitive data
Chris Lattnera58561b2004-08-12 19:12:28 +00001447are operated in parallel using a single instruction (SIMD).
Reid Spencer485bad12007-02-15 03:07:05 +00001448A vector type requires a size (number of
Chris Lattnerb8d172f2005-11-10 01:44:22 +00001449elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer485bad12007-02-15 03:07:05 +00001450of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnera58561b2004-08-12 19:12:28 +00001451considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +00001452
Chris Lattnera58561b2004-08-12 19:12:28 +00001453<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +00001454
1455<pre>
1456 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1457</pre>
1458
John Criswellc1f786c2005-05-13 22:25:59 +00001459<p>The number of elements is a constant integer value; elementtype may
Chris Lattner3b19d652007-01-15 01:54:13 +00001460be any integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +00001461
Chris Lattnera58561b2004-08-12 19:12:28 +00001462<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +00001463
Reid Spencerd3f876c2004-11-01 08:19:36 +00001464<table class="layout">
1465 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +00001466 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1467 <td class="left">Vector of 4 32-bit integer values.</td>
1468 </tr>
1469 <tr class="layout">
1470 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1471 <td class="left">Vector of 8 32-bit floating-point values.</td>
1472 </tr>
1473 <tr class="layout">
1474 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1475 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +00001476 </tr>
1477</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +00001478</div>
1479
Chris Lattner69c11bb2005-04-25 17:34:15 +00001480<!-- _______________________________________________________________________ -->
1481<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1482<div class="doc_text">
1483
1484<h5>Overview:</h5>
1485
1486<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksen8ac04ff2007-10-14 00:34:53 +00001487corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner69c11bb2005-04-25 17:34:15 +00001488In LLVM, opaque types can eventually be resolved to any type (not just a
1489structure type).</p>
1490
1491<h5>Syntax:</h5>
1492
1493<pre>
1494 opaque
1495</pre>
1496
1497<h5>Examples:</h5>
1498
1499<table class="layout">
1500 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +00001501 <td class="left"><tt>opaque</tt></td>
1502 <td class="left">An opaque type.</td>
Chris Lattner69c11bb2005-04-25 17:34:15 +00001503 </tr>
1504</table>
1505</div>
1506
1507
Chris Lattnerc3f59762004-12-09 17:30:23 +00001508<!-- *********************************************************************** -->
1509<div class="doc_section"> <a name="constants">Constants</a> </div>
1510<!-- *********************************************************************** -->
1511
1512<div class="doc_text">
1513
1514<p>LLVM has several different basic types of constants. This section describes
1515them all and their syntax.</p>
1516
1517</div>
1518
1519<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +00001520<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +00001521
1522<div class="doc_text">
1523
1524<dl>
1525 <dt><b>Boolean constants</b></dt>
1526
1527 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencerc78f3372007-01-12 03:35:51 +00001528 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattnerc3f59762004-12-09 17:30:23 +00001529 </dd>
1530
1531 <dt><b>Integer constants</b></dt>
1532
Reid Spencercc16dc32004-12-09 18:02:53 +00001533 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencera5173382007-01-04 16:43:23 +00001534 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattnerc3f59762004-12-09 17:30:23 +00001535 integer types.
1536 </dd>
1537
1538 <dt><b>Floating point constants</b></dt>
1539
1540 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1541 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattnera73afe02008-04-01 18:45:27 +00001542 notation (see below). The assembler requires the exact decimal value of
1543 a floating-point constant. For example, the assembler accepts 1.25 but
1544 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1545 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +00001546
1547 <dt><b>Null pointer constants</b></dt>
1548
John Criswell9e2485c2004-12-10 15:51:16 +00001549 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattnerc3f59762004-12-09 17:30:23 +00001550 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1551
1552</dl>
1553
John Criswell9e2485c2004-12-10 15:51:16 +00001554<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattnerc3f59762004-12-09 17:30:23 +00001555of floating point constants. For example, the form '<tt>double
15560x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
15574.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencercc16dc32004-12-09 18:02:53 +00001558(and the only time that they are generated by the disassembler) is when a
1559floating point constant must be emitted but it cannot be represented as a
1560decimal floating point number. For example, NaN's, infinities, and other
1561special values are represented in their IEEE hexadecimal format so that
1562assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +00001563
1564</div>
1565
1566<!-- ======================================================================= -->
1567<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1568</div>
1569
1570<div class="doc_text">
Chris Lattnerd4f6b172005-03-07 22:13:59 +00001571<p>Aggregate constants arise from aggregation of simple constants
1572and smaller aggregate constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +00001573
1574<dl>
1575 <dt><b>Structure constants</b></dt>
1576
1577 <dd>Structure constants are represented with notation similar to structure
1578 type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner64910ee2007-12-25 20:34:52 +00001579 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1580 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>". Structure constants
Chris Lattnerd4f6b172005-03-07 22:13:59 +00001581 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattnerc3f59762004-12-09 17:30:23 +00001582 types of elements must match those specified by the type.
1583 </dd>
1584
1585 <dt><b>Array constants</b></dt>
1586
1587 <dd>Array constants are represented with notation similar to array type
1588 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerca86e162006-12-31 07:07:53 +00001589 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattnerc3f59762004-12-09 17:30:23 +00001590 constants must have <a href="#t_array">array type</a>, and the number and
1591 types of elements must match those specified by the type.
1592 </dd>
1593
Reid Spencer485bad12007-02-15 03:07:05 +00001594 <dt><b>Vector constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +00001595
Reid Spencer485bad12007-02-15 03:07:05 +00001596 <dd>Vector constants are represented with notation similar to vector type
Chris Lattnerc3f59762004-12-09 17:30:23 +00001597 definitions (a comma separated list of elements, surrounded by
Reid Spencerca86e162006-12-31 07:07:53 +00001598 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32 42,
Jeff Cohen6f1cc772007-04-22 01:17:39 +00001599 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer485bad12007-02-15 03:07:05 +00001600 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattnerc3f59762004-12-09 17:30:23 +00001601 match those specified by the type.
1602 </dd>
1603
1604 <dt><b>Zero initialization</b></dt>
1605
1606 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1607 value to zero of <em>any</em> type, including scalar and aggregate types.
1608 This is often used to avoid having to print large zero initializers (e.g. for
John Criswell0ec250c2005-10-24 16:17:18 +00001609 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattnerc3f59762004-12-09 17:30:23 +00001610 initializers.
1611 </dd>
1612</dl>
1613
1614</div>
1615
1616<!-- ======================================================================= -->
1617<div class="doc_subsection">
1618 <a name="globalconstants">Global Variable and Function Addresses</a>
1619</div>
1620
1621<div class="doc_text">
1622
1623<p>The addresses of <a href="#globalvars">global variables</a> and <a
1624href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell9e2485c2004-12-10 15:51:16 +00001625constants. These constants are explicitly referenced when the <a
1626href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattnerc3f59762004-12-09 17:30:23 +00001627href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1628file:</p>
1629
Bill Wendling2f7a8b02007-05-29 09:04:49 +00001630<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +00001631<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +00001632@X = global i32 17
1633@Y = global i32 42
1634@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +00001635</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +00001636</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +00001637
1638</div>
1639
1640<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +00001641<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +00001642<div class="doc_text">
Reid Spencer2dc45b82004-12-09 18:13:12 +00001643 <p>The string '<tt>undef</tt>' is recognized as a type-less constant that has
John Criswellc1f786c2005-05-13 22:25:59 +00001644 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer2dc45b82004-12-09 18:13:12 +00001645 a constant is permitted.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +00001646
Reid Spencer2dc45b82004-12-09 18:13:12 +00001647 <p>Undefined values indicate to the compiler that the program is well defined
1648 no matter what value is used, giving the compiler more freedom to optimize.
1649 </p>
Chris Lattnerc3f59762004-12-09 17:30:23 +00001650</div>
1651
1652<!-- ======================================================================= -->
1653<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1654</div>
1655
1656<div class="doc_text">
1657
1658<p>Constant expressions are used to allow expressions involving other constants
1659to be used as constants. Constant expressions may be of any <a
John Criswellc1f786c2005-05-13 22:25:59 +00001660href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattnerc3f59762004-12-09 17:30:23 +00001661that does not have side effects (e.g. load and call are not supported). The
1662following is the syntax for constant expressions:</p>
1663
1664<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00001665 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1666 <dd>Truncate a constant to another type. The bit size of CST must be larger
Chris Lattner3b19d652007-01-15 01:54:13 +00001667 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +00001668
Reid Spencer9dee3ac2006-11-08 01:11:31 +00001669 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1670 <dd>Zero extend a constant to another type. The bit size of CST must be
Chris Lattner3b19d652007-01-15 01:54:13 +00001671 smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00001672
1673 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1674 <dd>Sign extend a constant to another type. The bit size of CST must be
Chris Lattner3b19d652007-01-15 01:54:13 +00001675 smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00001676
1677 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1678 <dd>Truncate a floating point constant to another floating point type. The
1679 size of CST must be larger than the size of TYPE. Both types must be
1680 floating point.</dd>
1681
1682 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1683 <dd>Floating point extend a constant to another type. The size of CST must be
1684 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1685
Reid Spencer1539a1c2007-07-31 14:40:14 +00001686 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00001687 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemanb348d182007-11-17 03:58:34 +00001688 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1689 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1690 of the same number of elements. If the value won't fit in the integer type,
1691 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00001692
Reid Spencerd4448792006-11-09 23:03:26 +00001693 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00001694 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemanb348d182007-11-17 03:58:34 +00001695 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1696 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1697 of the same number of elements. If the value won't fit in the integer type,
1698 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00001699
Reid Spencerd4448792006-11-09 23:03:26 +00001700 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00001701 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +00001702 constant. TYPE must be a scalar or vector floating point type. CST must be of
1703 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1704 of the same number of elements. If the value won't fit in the floating point
1705 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00001706
Reid Spencerd4448792006-11-09 23:03:26 +00001707 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00001708 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +00001709 constant. TYPE must be a scalar or vector floating point type. CST must be of
1710 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1711 of the same number of elements. If the value won't fit in the floating point
1712 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00001713
Reid Spencer5c0ef472006-11-11 23:08:07 +00001714 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1715 <dd>Convert a pointer typed constant to the corresponding integer constant
1716 TYPE must be an integer type. CST must be of pointer type. The CST value is
1717 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1718
1719 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1720 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1721 pointer type. CST must be of integer type. The CST value is zero extended,
1722 truncated, or unchanged to make it fit in a pointer size. This one is
1723 <i>really</i> dangerous!</dd>
1724
1725 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00001726 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1727 identical (same number of bits). The conversion is done as if the CST value
1728 was stored to memory and read back as TYPE. In other words, no bits change
Reid Spencer5c0ef472006-11-11 23:08:07 +00001729 with this operator, just the type. This can be used for conversion of
Reid Spencer485bad12007-02-15 03:07:05 +00001730 vector types to any other type, as long as they have the same bit width. For
Reid Spencer5c0ef472006-11-11 23:08:07 +00001731 pointers it is only valid to cast to another pointer type.
Reid Spencer9dee3ac2006-11-08 01:11:31 +00001732 </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +00001733
1734 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1735
1736 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1737 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1738 instruction, the index list may have zero or more indexes, which are required
1739 to make sense for the type of "CSTPTR".</dd>
1740
Robert Bocchino9fbe1452006-01-10 19:31:34 +00001741 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1742
1743 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer01c42592006-12-04 19:23:19 +00001744 constants.</dd>
1745
1746 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1747 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1748
1749 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1750 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +00001751
Nate Begemanac80ade2008-05-12 19:01:56 +00001752 <dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
1753 <dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
1754
1755 <dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
1756 <dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
1757
Robert Bocchino9fbe1452006-01-10 19:31:34 +00001758 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1759
1760 <dd>Perform the <a href="#i_extractelement">extractelement
1761 operation</a> on constants.
1762
Robert Bocchino05ccd702006-01-15 20:48:27 +00001763 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1764
1765 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer01c42592006-12-04 19:23:19 +00001766 operation</a> on constants.</dd>
Robert Bocchino05ccd702006-01-15 20:48:27 +00001767
Chris Lattnerc1989542006-04-08 00:13:41 +00001768
1769 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1770
1771 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer01c42592006-12-04 19:23:19 +00001772 operation</a> on constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +00001773
Chris Lattnerc3f59762004-12-09 17:30:23 +00001774 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1775
Reid Spencer2dc45b82004-12-09 18:13:12 +00001776 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1777 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattnerc3f59762004-12-09 17:30:23 +00001778 binary</a> operations. The constraints on operands are the same as those for
1779 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswelle4c57cc2005-05-12 16:52:32 +00001780 values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +00001781</dl>
Chris Lattnerc3f59762004-12-09 17:30:23 +00001782</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +00001783
Chris Lattner00950542001-06-06 20:29:01 +00001784<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +00001785<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1786<!-- *********************************************************************** -->
1787
1788<!-- ======================================================================= -->
1789<div class="doc_subsection">
1790<a name="inlineasm">Inline Assembler Expressions</a>
1791</div>
1792
1793<div class="doc_text">
1794
1795<p>
1796LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1797Module-Level Inline Assembly</a>) through the use of a special value. This
1798value represents the inline assembler as a string (containing the instructions
1799to emit), a list of operand constraints (stored as a string), and a flag that
1800indicates whether or not the inline asm expression has side effects. An example
1801inline assembler expression is:
1802</p>
1803
Bill Wendling2f7a8b02007-05-29 09:04:49 +00001804<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +00001805<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +00001806i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +00001807</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +00001808</div>
Chris Lattnere87d6532006-01-25 23:47:57 +00001809
1810<p>
1811Inline assembler expressions may <b>only</b> be used as the callee operand of
1812a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
1813</p>
1814
Bill Wendling2f7a8b02007-05-29 09:04:49 +00001815<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +00001816<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +00001817%X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y)
Chris Lattnere87d6532006-01-25 23:47:57 +00001818</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +00001819</div>
Chris Lattnere87d6532006-01-25 23:47:57 +00001820
1821<p>
1822Inline asms with side effects not visible in the constraint list must be marked
1823as having side effects. This is done through the use of the
1824'<tt>sideeffect</tt>' keyword, like so:
1825</p>
1826
Bill Wendling2f7a8b02007-05-29 09:04:49 +00001827<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +00001828<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +00001829call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +00001830</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +00001831</div>
Chris Lattnere87d6532006-01-25 23:47:57 +00001832
1833<p>TODO: The format of the asm and constraints string still need to be
1834documented here. Constraints on what can be done (e.g. duplication, moving, etc
1835need to be documented).
1836</p>
1837
1838</div>
1839
1840<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +00001841<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
1842<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +00001843
Misha Brukman9d0919f2003-11-08 01:05:38 +00001844<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +00001845
Chris Lattner261efe92003-11-25 01:02:51 +00001846<p>The LLVM instruction set consists of several different
1847classifications of instructions: <a href="#terminators">terminator
John Criswellc1f786c2005-05-13 22:25:59 +00001848instructions</a>, <a href="#binaryops">binary instructions</a>,
1849<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner261efe92003-11-25 01:02:51 +00001850 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
1851instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +00001852
Misha Brukman9d0919f2003-11-08 01:05:38 +00001853</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +00001854
Chris Lattner00950542001-06-06 20:29:01 +00001855<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +00001856<div class="doc_subsection"> <a name="terminators">Terminator
1857Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +00001858
Misha Brukman9d0919f2003-11-08 01:05:38 +00001859<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +00001860
Chris Lattner261efe92003-11-25 01:02:51 +00001861<p>As mentioned <a href="#functionstructure">previously</a>, every
1862basic block in a program ends with a "Terminator" instruction, which
1863indicates which block should be executed after the current block is
1864finished. These terminator instructions typically yield a '<tt>void</tt>'
1865value: they produce control flow, not values (the one exception being
1866the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell9e2485c2004-12-10 15:51:16 +00001867<p>There are six different terminator instructions: the '<a
Chris Lattner261efe92003-11-25 01:02:51 +00001868 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
1869instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner35eca582004-10-16 18:04:13 +00001870the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
1871 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
1872 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +00001873
Misha Brukman9d0919f2003-11-08 01:05:38 +00001874</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +00001875
Chris Lattner00950542001-06-06 20:29:01 +00001876<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +00001877<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
1878Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +00001879<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +00001880<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +00001881<pre> ret &lt;type&gt; &lt;value&gt; <i>; Return a value from a non-void function</i>
Chris Lattner7faa8832002-04-14 06:13:44 +00001882 ret void <i>; Return from void function</i>
Devang Patelc3fc6df2008-03-10 20:49:15 +00001883 ret &lt;type&gt; &lt;value&gt;, &lt;type&gt; &lt;value&gt; <i>; Return two values from a non-void function </i>
Chris Lattner00950542001-06-06 20:29:01 +00001884</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +00001885
Chris Lattner00950542001-06-06 20:29:01 +00001886<h5>Overview:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +00001887
Chris Lattner261efe92003-11-25 01:02:51 +00001888<p>The '<tt>ret</tt>' instruction is used to return control flow (and a
John Criswellc1f786c2005-05-13 22:25:59 +00001889value) from a function back to the caller.</p>
John Criswell4457dc92004-04-09 16:48:45 +00001890<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Chris Lattnerf4cde4e2008-04-23 04:59:35 +00001891returns value(s) and then causes control flow, and one that just causes
Chris Lattner261efe92003-11-25 01:02:51 +00001892control flow to occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +00001893
Chris Lattner00950542001-06-06 20:29:01 +00001894<h5>Arguments:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +00001895
1896<p>The '<tt>ret</tt>' instruction may return zero, one or multiple values.
1897The type of each return value must be a '<a href="#t_firstclass">first
1898class</a>' type. Note that a function is not <a href="#wellformed">well
1899formed</a> if there exists a '<tt>ret</tt>' instruction inside of the
1900function that returns values that do not match the return type of the
1901function.</p>
1902
Chris Lattner00950542001-06-06 20:29:01 +00001903<h5>Semantics:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +00001904
Chris Lattner261efe92003-11-25 01:02:51 +00001905<p>When the '<tt>ret</tt>' instruction is executed, control flow
1906returns back to the calling function's context. If the caller is a "<a
John Criswellfa081872004-06-25 15:16:57 +00001907 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner261efe92003-11-25 01:02:51 +00001908the instruction after the call. If the caller was an "<a
1909 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswelle4c57cc2005-05-12 16:52:32 +00001910at the beginning of the "normal" destination block. If the instruction
Chris Lattner261efe92003-11-25 01:02:51 +00001911returns a value, that value shall set the call or invoke instruction's
Devang Patelc3fc6df2008-03-10 20:49:15 +00001912return value. If the instruction returns multiple values then these
Devang Patel0dbb4a12008-03-11 05:51:59 +00001913values can only be accessed through a '<a href="#i_getresult"><tt>getresult</tt>
1914</a>' instruction.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +00001915
Chris Lattner00950542001-06-06 20:29:01 +00001916<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +00001917
1918<pre>
1919 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +00001920 ret void <i>; Return from a void function</i>
Devang Patelc3fc6df2008-03-10 20:49:15 +00001921 ret i32 4, i8 2 <i>; Return two values 4 and 2 </i>
Chris Lattner00950542001-06-06 20:29:01 +00001922</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +00001923</div>
Chris Lattner00950542001-06-06 20:29:01 +00001924<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +00001925<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +00001926<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +00001927<h5>Syntax:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +00001928<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 +00001929</pre>
Chris Lattner00950542001-06-06 20:29:01 +00001930<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +00001931<p>The '<tt>br</tt>' instruction is used to cause control flow to
1932transfer to a different basic block in the current function. There are
1933two forms of this instruction, corresponding to a conditional branch
1934and an unconditional branch.</p>
Chris Lattner00950542001-06-06 20:29:01 +00001935<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +00001936<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencerc78f3372007-01-12 03:35:51 +00001937single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencerde151942007-02-19 23:54:10 +00001938unconditional form of the '<tt>br</tt>' instruction takes a single
1939'<tt>label</tt>' value as a target.</p>
Chris Lattner00950542001-06-06 20:29:01 +00001940<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +00001941<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +00001942argument is evaluated. If the value is <tt>true</tt>, control flows
1943to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
1944control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner00950542001-06-06 20:29:01 +00001945<h5>Example:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +00001946<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 +00001947 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 +00001948</div>
Chris Lattner00950542001-06-06 20:29:01 +00001949<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +00001950<div class="doc_subsubsection">
1951 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
1952</div>
1953
Misha Brukman9d0919f2003-11-08 01:05:38 +00001954<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +00001955<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +00001956
1957<pre>
1958 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
1959</pre>
1960
Chris Lattner00950542001-06-06 20:29:01 +00001961<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +00001962
1963<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
1964several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman9d0919f2003-11-08 01:05:38 +00001965instruction, allowing a branch to occur to one of many possible
1966destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +00001967
1968
Chris Lattner00950542001-06-06 20:29:01 +00001969<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +00001970
1971<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
1972comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
1973an array of pairs of comparison value constants and '<tt>label</tt>'s. The
1974table is not allowed to contain duplicate constant entries.</p>
1975
Chris Lattner00950542001-06-06 20:29:01 +00001976<h5>Semantics:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +00001977
Chris Lattner261efe92003-11-25 01:02:51 +00001978<p>The <tt>switch</tt> instruction specifies a table of values and
1979destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell84114752004-06-25 16:05:06 +00001980table is searched for the given value. If the value is found, control flow is
1981transfered to the corresponding destination; otherwise, control flow is
1982transfered to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +00001983
Chris Lattnerc88c17b2004-02-24 04:54:45 +00001984<h5>Implementation:</h5>
1985
1986<p>Depending on properties of the target machine and the particular
1987<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell84114752004-06-25 16:05:06 +00001988ways. For example, it could be generated as a series of chained conditional
1989branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +00001990
1991<h5>Example:</h5>
1992
1993<pre>
1994 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +00001995 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencerca86e162006-12-31 07:07:53 +00001996 switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +00001997
1998 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +00001999 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +00002000
2001 <i>; Implement a jump table:</i>
Reid Spencerca86e162006-12-31 07:07:53 +00002002 switch i32 %val, label %otherwise [ i32 0, label %onzero
2003 i32 1, label %onone
2004 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +00002005</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +00002006</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +00002007
Chris Lattner00950542001-06-06 20:29:01 +00002008<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +00002009<div class="doc_subsubsection">
2010 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2011</div>
2012
Misha Brukman9d0919f2003-11-08 01:05:38 +00002013<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +00002014
Chris Lattner00950542001-06-06 20:29:01 +00002015<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +00002016
2017<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +00002018 &lt;result&gt; = invoke [<a href="#callingconv">cconv</a>] &lt;ptr to function ty&gt; &lt;function ptr val&gt;(&lt;function args&gt;)
Chris Lattner76b8a332006-05-14 18:23:06 +00002019 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +00002020</pre>
2021
Chris Lattner6536cfe2002-05-06 22:08:29 +00002022<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +00002023
2024<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
2025function, with the possibility of control flow transfer to either the
John Criswelle4c57cc2005-05-12 16:52:32 +00002026'<tt>normal</tt>' label or the
2027'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattnerbad10ee2005-05-06 22:57:40 +00002028"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
2029"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswelle4c57cc2005-05-12 16:52:32 +00002030href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Devang Patelc3fc6df2008-03-10 20:49:15 +00002031continued at the dynamically nearest "exception" label. If the callee function
Devang Patel0dbb4a12008-03-11 05:51:59 +00002032returns multiple values then individual return values are only accessible through
2033a '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +00002034
Chris Lattner00950542001-06-06 20:29:01 +00002035<h5>Arguments:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +00002036
Misha Brukman9d0919f2003-11-08 01:05:38 +00002037<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +00002038
Chris Lattner00950542001-06-06 20:29:01 +00002039<ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +00002040 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +00002041 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +00002042 convention</a> the call should use. If none is specified, the call defaults
2043 to using C calling conventions.
2044 </li>
2045 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
2046 function value being invoked. In most cases, this is a direct function
2047 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
2048 an arbitrary pointer to function value.
2049 </li>
2050
2051 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
2052 function to be invoked. </li>
2053
2054 <li>'<tt>function args</tt>': argument list whose types match the function
2055 signature argument types. If the function signature indicates the function
2056 accepts a variable number of arguments, the extra arguments can be
2057 specified. </li>
2058
2059 <li>'<tt>normal label</tt>': the label reached when the called function
2060 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
2061
2062 <li>'<tt>exception label</tt>': the label reached when a callee returns with
2063 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
2064
Chris Lattner00950542001-06-06 20:29:01 +00002065</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +00002066
Chris Lattner00950542001-06-06 20:29:01 +00002067<h5>Semantics:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +00002068
Misha Brukman9d0919f2003-11-08 01:05:38 +00002069<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattnerbad10ee2005-05-06 22:57:40 +00002070href="#i_call">call</a></tt>' instruction in most regards. The primary
2071difference is that it establishes an association with a label, which is used by
2072the runtime library to unwind the stack.</p>
2073
2074<p>This instruction is used in languages with destructors to ensure that proper
2075cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2076exception. Additionally, this is important for implementation of
2077'<tt>catch</tt>' clauses in high-level languages that support them.</p>
2078
Chris Lattner00950542001-06-06 20:29:01 +00002079<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +00002080<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +00002081 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +00002082 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +00002083 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +00002084 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +00002085</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +00002086</div>
Chris Lattner35eca582004-10-16 18:04:13 +00002087
2088
Chris Lattner27f71f22003-09-03 00:41:47 +00002089<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +00002090
Chris Lattner261efe92003-11-25 01:02:51 +00002091<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2092Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +00002093
Misha Brukman9d0919f2003-11-08 01:05:38 +00002094<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +00002095
Chris Lattner27f71f22003-09-03 00:41:47 +00002096<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +00002097<pre>
2098 unwind
2099</pre>
2100
Chris Lattner27f71f22003-09-03 00:41:47 +00002101<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +00002102
2103<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
2104at the first callee in the dynamic call stack which used an <a
2105href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
2106primarily used to implement exception handling.</p>
2107
Chris Lattner27f71f22003-09-03 00:41:47 +00002108<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +00002109
Chris Lattner72ed2002008-04-19 21:01:16 +00002110<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner35eca582004-10-16 18:04:13 +00002111immediately halt. The dynamic call stack is then searched for the first <a
2112href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
2113execution continues at the "exceptional" destination block specified by the
2114<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
2115dynamic call chain, undefined behavior results.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +00002116</div>
Chris Lattner35eca582004-10-16 18:04:13 +00002117
2118<!-- _______________________________________________________________________ -->
2119
2120<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2121Instruction</a> </div>
2122
2123<div class="doc_text">
2124
2125<h5>Syntax:</h5>
2126<pre>
2127 unreachable
2128</pre>
2129
2130<h5>Overview:</h5>
2131
2132<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
2133instruction is used to inform the optimizer that a particular portion of the
2134code is not reachable. This can be used to indicate that the code after a
2135no-return function cannot be reached, and other facts.</p>
2136
2137<h5>Semantics:</h5>
2138
2139<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
2140</div>
2141
2142
2143
Chris Lattner00950542001-06-06 20:29:01 +00002144<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +00002145<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +00002146<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +00002147<p>Binary operators are used to do most of the computation in a
Chris Lattner5a158142008-04-01 18:47:32 +00002148program. They require two operands of the same type, execute an operation on them, and
John Criswell9e2485c2004-12-10 15:51:16 +00002149produce a single value. The operands might represent
Reid Spencer485bad12007-02-15 03:07:05 +00002150multiple data, as is the case with the <a href="#t_vector">vector</a> data type.
Chris Lattner5a158142008-04-01 18:47:32 +00002151The result value has the same type as its operands.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +00002152<p>There are several different binary operators:</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +00002153</div>
Chris Lattner00950542001-06-06 20:29:01 +00002154<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +00002155<div class="doc_subsubsection">
2156 <a name="i_add">'<tt>add</tt>' Instruction</a>
2157</div>
2158
Misha Brukman9d0919f2003-11-08 01:05:38 +00002159<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +00002160
Chris Lattner00950542001-06-06 20:29:01 +00002161<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002162
2163<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +00002164 &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 +00002165</pre>
Chris Lattner5568e942008-05-20 20:48:21 +00002166
Chris Lattner00950542001-06-06 20:29:01 +00002167<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002168
Misha Brukman9d0919f2003-11-08 01:05:38 +00002169<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +00002170
Chris Lattner00950542001-06-06 20:29:01 +00002171<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002172
2173<p>The two arguments to the '<tt>add</tt>' instruction must be <a
2174 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
2175 <a href="#t_vector">vector</a> values. Both arguments must have identical
2176 types.</p>
2177
Chris Lattner00950542001-06-06 20:29:01 +00002178<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002179
Misha Brukman9d0919f2003-11-08 01:05:38 +00002180<p>The value produced is the integer or floating point sum of the two
2181operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +00002182
Chris Lattner5ec89832008-01-28 00:36:27 +00002183<p>If an integer sum has unsigned overflow, the result returned is the
2184mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2185the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +00002186
Chris Lattner5ec89832008-01-28 00:36:27 +00002187<p>Because LLVM integers use a two's complement representation, this
2188instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +00002189
Chris Lattner00950542001-06-06 20:29:01 +00002190<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002191
2192<pre>
2193 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +00002194</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +00002195</div>
Chris Lattner00950542001-06-06 20:29:01 +00002196<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +00002197<div class="doc_subsubsection">
2198 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2199</div>
2200
Misha Brukman9d0919f2003-11-08 01:05:38 +00002201<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +00002202
Chris Lattner00950542001-06-06 20:29:01 +00002203<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002204
2205<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +00002206 &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 +00002207</pre>
Chris Lattner5568e942008-05-20 20:48:21 +00002208
Chris Lattner00950542001-06-06 20:29:01 +00002209<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002210
Misha Brukman9d0919f2003-11-08 01:05:38 +00002211<p>The '<tt>sub</tt>' instruction returns the difference of its two
2212operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +00002213
2214<p>Note that the '<tt>sub</tt>' instruction is used to represent the
2215'<tt>neg</tt>' instruction present in most other intermediate
2216representations.</p>
2217
Chris Lattner00950542001-06-06 20:29:01 +00002218<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002219
2220<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
2221 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2222 or <a href="#t_vector">vector</a> values. Both arguments must have identical
2223 types.</p>
2224
Chris Lattner00950542001-06-06 20:29:01 +00002225<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002226
Chris Lattner261efe92003-11-25 01:02:51 +00002227<p>The value produced is the integer or floating point difference of
2228the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +00002229
Chris Lattner5ec89832008-01-28 00:36:27 +00002230<p>If an integer difference has unsigned overflow, the result returned is the
2231mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2232the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +00002233
Chris Lattner5ec89832008-01-28 00:36:27 +00002234<p>Because LLVM integers use a two's complement representation, this
2235instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +00002236
Chris Lattner00950542001-06-06 20:29:01 +00002237<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +00002238<pre>
2239 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +00002240 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +00002241</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +00002242</div>
Chris Lattner5568e942008-05-20 20:48:21 +00002243
Chris Lattner00950542001-06-06 20:29:01 +00002244<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +00002245<div class="doc_subsubsection">
2246 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2247</div>
2248
Misha Brukman9d0919f2003-11-08 01:05:38 +00002249<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +00002250
Chris Lattner00950542001-06-06 20:29:01 +00002251<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +00002252<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 +00002253</pre>
Chris Lattner00950542001-06-06 20:29:01 +00002254<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +00002255<p>The '<tt>mul</tt>' instruction returns the product of its two
2256operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +00002257
Chris Lattner00950542001-06-06 20:29:01 +00002258<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002259
2260<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
2261href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2262or <a href="#t_vector">vector</a> values. Both arguments must have identical
2263types.</p>
2264
Chris Lattner00950542001-06-06 20:29:01 +00002265<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002266
Chris Lattner261efe92003-11-25 01:02:51 +00002267<p>The value produced is the integer or floating point product of the
Misha Brukman9d0919f2003-11-08 01:05:38 +00002268two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +00002269
Chris Lattner5ec89832008-01-28 00:36:27 +00002270<p>If the result of an integer multiplication has unsigned overflow,
2271the result returned is the mathematical result modulo
22722<sup>n</sup>, where n is the bit width of the result.</p>
2273<p>Because LLVM integers use a two's complement representation, and the
2274result is the same width as the operands, this instruction returns the
2275correct result for both signed and unsigned integers. If a full product
2276(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
2277should be sign-extended or zero-extended as appropriate to the
2278width of the full product.</p>
Chris Lattner00950542001-06-06 20:29:01 +00002279<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +00002280<pre> &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +00002281</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +00002282</div>
Chris Lattner5568e942008-05-20 20:48:21 +00002283
Chris Lattner00950542001-06-06 20:29:01 +00002284<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +00002285<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2286</a></div>
2287<div class="doc_text">
2288<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +00002289<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 +00002290</pre>
2291<h5>Overview:</h5>
2292<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2293operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +00002294
Reid Spencer1628cec2006-10-26 06:15:43 +00002295<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002296
Reid Spencer1628cec2006-10-26 06:15:43 +00002297<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +00002298<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2299values. Both arguments must have identical types.</p>
2300
Reid Spencer1628cec2006-10-26 06:15:43 +00002301<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002302
Chris Lattner5ec89832008-01-28 00:36:27 +00002303<p>The value produced is the unsigned integer quotient of the two operands.</p>
2304<p>Note that unsigned integer division and signed integer division are distinct
2305operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2306<p>Division by zero leads to undefined behavior.</p>
Reid Spencer1628cec2006-10-26 06:15:43 +00002307<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +00002308<pre> &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +00002309</pre>
2310</div>
2311<!-- _______________________________________________________________________ -->
2312<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2313</a> </div>
2314<div class="doc_text">
2315<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002316<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +00002317 &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 +00002318</pre>
Chris Lattner5568e942008-05-20 20:48:21 +00002319
Reid Spencer1628cec2006-10-26 06:15:43 +00002320<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002321
Reid Spencer1628cec2006-10-26 06:15:43 +00002322<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2323operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +00002324
Reid Spencer1628cec2006-10-26 06:15:43 +00002325<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002326
2327<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2328<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2329values. Both arguments must have identical types.</p>
2330
Reid Spencer1628cec2006-10-26 06:15:43 +00002331<h5>Semantics:</h5>
Chris Lattnera73afe02008-04-01 18:45:27 +00002332<p>The value produced is the signed integer quotient of the two operands rounded towards zero.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +00002333<p>Note that signed integer division and unsigned integer division are distinct
2334operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2335<p>Division by zero leads to undefined behavior. Overflow also leads to
2336undefined behavior; this is a rare case, but can occur, for example,
2337by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer1628cec2006-10-26 06:15:43 +00002338<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +00002339<pre> &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +00002340</pre>
2341</div>
2342<!-- _______________________________________________________________________ -->
2343<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +00002344Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +00002345<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +00002346<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002347<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +00002348 &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 +00002349</pre>
2350<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002351
Reid Spencer1628cec2006-10-26 06:15:43 +00002352<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner261efe92003-11-25 01:02:51 +00002353operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +00002354
Chris Lattner261efe92003-11-25 01:02:51 +00002355<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002356
Jeff Cohen6f1cc772007-04-22 01:17:39 +00002357<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +00002358<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2359of floating point values. Both arguments must have identical types.</p>
2360
Chris Lattner261efe92003-11-25 01:02:51 +00002361<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002362
Reid Spencer1628cec2006-10-26 06:15:43 +00002363<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +00002364
Chris Lattner261efe92003-11-25 01:02:51 +00002365<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002366
2367<pre>
2368 &lt;result&gt; = fdiv float 4.0, %var <i>; yields {float}:result = 4.0 / %var</i>
Chris Lattner261efe92003-11-25 01:02:51 +00002369</pre>
2370</div>
Chris Lattner5568e942008-05-20 20:48:21 +00002371
Chris Lattner261efe92003-11-25 01:02:51 +00002372<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +00002373<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2374</div>
2375<div class="doc_text">
2376<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +00002377<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 +00002378</pre>
2379<h5>Overview:</h5>
2380<p>The '<tt>urem</tt>' instruction returns the remainder from the
2381unsigned division of its two arguments.</p>
2382<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002383<p>The two arguments to the '<tt>urem</tt>' instruction must be
2384<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2385values. Both arguments must have identical types.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +00002386<h5>Semantics:</h5>
2387<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattnera73afe02008-04-01 18:45:27 +00002388This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +00002389<p>Note that unsigned integer remainder and signed integer remainder are
2390distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
2391<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +00002392<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +00002393<pre> &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +00002394</pre>
2395
2396</div>
2397<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +00002398<div class="doc_subsubsection">
2399 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
2400</div>
2401
Chris Lattner261efe92003-11-25 01:02:51 +00002402<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +00002403
Chris Lattner261efe92003-11-25 01:02:51 +00002404<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002405
2406<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +00002407 &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 +00002408</pre>
Chris Lattner5568e942008-05-20 20:48:21 +00002409
Chris Lattner261efe92003-11-25 01:02:51 +00002410<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002411
Reid Spencer0a783f72006-11-02 01:53:59 +00002412<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman80176312007-11-05 23:35:22 +00002413signed division of its two operands. This instruction can also take
2414<a href="#t_vector">vector</a> versions of the values in which case
2415the elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +00002416
Chris Lattner261efe92003-11-25 01:02:51 +00002417<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002418
Reid Spencer0a783f72006-11-02 01:53:59 +00002419<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +00002420<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2421values. Both arguments must have identical types.</p>
2422
Chris Lattner261efe92003-11-25 01:02:51 +00002423<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002424
Reid Spencer0a783f72006-11-02 01:53:59 +00002425<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greiffb224a22008-08-07 21:46:00 +00002426has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
2427operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencerc9fdfc82007-03-24 22:23:39 +00002428a value. For more information about the difference, see <a
Chris Lattner261efe92003-11-25 01:02:51 +00002429 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencerc9fdfc82007-03-24 22:23:39 +00002430Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencer64f5c6c2007-03-24 22:40:44 +00002431please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencerc9fdfc82007-03-24 22:23:39 +00002432Wikipedia: modulo operation</a>.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +00002433<p>Note that signed integer remainder and unsigned integer remainder are
2434distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
2435<p>Taking the remainder of a division by zero leads to undefined behavior.
2436Overflow also leads to undefined behavior; this is a rare case, but can occur,
2437for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
2438(The remainder doesn't actually overflow, but this rule lets srem be
2439implemented using instructions that return both the result of the division
2440and the remainder.)</p>
Chris Lattner261efe92003-11-25 01:02:51 +00002441<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +00002442<pre> &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +00002443</pre>
2444
2445</div>
2446<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +00002447<div class="doc_subsubsection">
2448 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
2449
Reid Spencer0a783f72006-11-02 01:53:59 +00002450<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +00002451
Reid Spencer0a783f72006-11-02 01:53:59 +00002452<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +00002453<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 +00002454</pre>
2455<h5>Overview:</h5>
2456<p>The '<tt>frem</tt>' instruction returns the remainder from the
2457division of its two operands.</p>
2458<h5>Arguments:</h5>
2459<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +00002460<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2461of floating point values. Both arguments must have identical types.</p>
2462
Reid Spencer0a783f72006-11-02 01:53:59 +00002463<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002464
Chris Lattnera73afe02008-04-01 18:45:27 +00002465<p>This instruction returns the <i>remainder</i> of a division.
2466The remainder has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +00002467
Reid Spencer0a783f72006-11-02 01:53:59 +00002468<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002469
2470<pre>
2471 &lt;result&gt; = frem float 4.0, %var <i>; yields {float}:result = 4.0 % %var</i>
Chris Lattner261efe92003-11-25 01:02:51 +00002472</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +00002473</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +00002474
Reid Spencer8e11bf82007-02-02 13:57:07 +00002475<!-- ======================================================================= -->
2476<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2477Operations</a> </div>
2478<div class="doc_text">
2479<p>Bitwise binary operators are used to do various forms of
2480bit-twiddling in a program. They are generally very efficient
2481instructions and can commonly be strength reduced from other
Chris Lattnera73afe02008-04-01 18:45:27 +00002482instructions. They require two operands of the same type, execute an operation on them,
2483and produce a single value. The resulting value is the same type as its operands.</p>
Reid Spencer8e11bf82007-02-02 13:57:07 +00002484</div>
2485
Reid Spencer569f2fa2007-01-31 21:39:12 +00002486<!-- _______________________________________________________________________ -->
2487<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2488Instruction</a> </div>
2489<div class="doc_text">
2490<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +00002491<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 +00002492</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +00002493
Reid Spencer569f2fa2007-01-31 21:39:12 +00002494<h5>Overview:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +00002495
Reid Spencer569f2fa2007-01-31 21:39:12 +00002496<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2497the left a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +00002498
Reid Spencer569f2fa2007-01-31 21:39:12 +00002499<h5>Arguments:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +00002500
Reid Spencer569f2fa2007-01-31 21:39:12 +00002501<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begeman5bc1ea02008-07-29 15:49:41 +00002502 href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greiffb224a22008-08-07 21:46:00 +00002503type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +00002504
Reid Spencer569f2fa2007-01-31 21:39:12 +00002505<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +00002506
Gabor Greiffb224a22008-08-07 21:46:00 +00002507<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
2508where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
2509equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +00002510
Reid Spencer569f2fa2007-01-31 21:39:12 +00002511<h5>Example:</h5><pre>
2512 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2513 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2514 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +00002515 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +00002516</pre>
2517</div>
2518<!-- _______________________________________________________________________ -->
2519<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2520Instruction</a> </div>
2521<div class="doc_text">
2522<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +00002523<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 +00002524</pre>
2525
2526<h5>Overview:</h5>
2527<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +00002528operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +00002529
2530<h5>Arguments:</h5>
2531<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begeman5bc1ea02008-07-29 15:49:41 +00002532<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greiffb224a22008-08-07 21:46:00 +00002533type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +00002534
2535<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +00002536
Reid Spencer569f2fa2007-01-31 21:39:12 +00002537<p>This instruction always performs a logical shift right operation. The most
2538significant bits of the result will be filled with zero bits after the
Gabor Greiffb224a22008-08-07 21:46:00 +00002539shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
2540the number of bits in <tt>op1</tt>, the result is undefined.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +00002541
2542<h5>Example:</h5>
2543<pre>
2544 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2545 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2546 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2547 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +00002548 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +00002549</pre>
2550</div>
2551
Reid Spencer8e11bf82007-02-02 13:57:07 +00002552<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +00002553<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2554Instruction</a> </div>
2555<div class="doc_text">
2556
2557<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +00002558<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 +00002559</pre>
2560
2561<h5>Overview:</h5>
2562<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +00002563operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +00002564
2565<h5>Arguments:</h5>
2566<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begeman5bc1ea02008-07-29 15:49:41 +00002567<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greiffb224a22008-08-07 21:46:00 +00002568type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +00002569
2570<h5>Semantics:</h5>
2571<p>This instruction always performs an arithmetic shift right operation,
2572The most significant bits of the result will be filled with the sign bit
Gabor Greiffb224a22008-08-07 21:46:00 +00002573of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
2574larger than the number of bits in <tt>op1</tt>, the result is undefined.
Chris Lattner6ccc2d52007-10-03 21:01:14 +00002575</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +00002576
2577<h5>Example:</h5>
2578<pre>
2579 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2580 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2581 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2582 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +00002583 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +00002584</pre>
2585</div>
2586
Chris Lattner00950542001-06-06 20:29:01 +00002587<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +00002588<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2589Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +00002590
Misha Brukman9d0919f2003-11-08 01:05:38 +00002591<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +00002592
Chris Lattner00950542001-06-06 20:29:01 +00002593<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002594
2595<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +00002596 &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 +00002597</pre>
Chris Lattner5568e942008-05-20 20:48:21 +00002598
Chris Lattner00950542001-06-06 20:29:01 +00002599<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002600
Chris Lattner261efe92003-11-25 01:02:51 +00002601<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2602its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +00002603
Chris Lattner00950542001-06-06 20:29:01 +00002604<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002605
2606<p>The two arguments to the '<tt>and</tt>' instruction must be
2607<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2608values. Both arguments must have identical types.</p>
2609
Chris Lattner00950542001-06-06 20:29:01 +00002610<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +00002611<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +00002612<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +00002613<div style="align: center">
Misha Brukman9d0919f2003-11-08 01:05:38 +00002614<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +00002615 <tbody>
2616 <tr>
2617 <td>In0</td>
2618 <td>In1</td>
2619 <td>Out</td>
2620 </tr>
2621 <tr>
2622 <td>0</td>
2623 <td>0</td>
2624 <td>0</td>
2625 </tr>
2626 <tr>
2627 <td>0</td>
2628 <td>1</td>
2629 <td>0</td>
2630 </tr>
2631 <tr>
2632 <td>1</td>
2633 <td>0</td>
2634 <td>0</td>
2635 </tr>
2636 <tr>
2637 <td>1</td>
2638 <td>1</td>
2639 <td>1</td>
2640 </tr>
2641 </tbody>
2642</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +00002643</div>
Chris Lattner00950542001-06-06 20:29:01 +00002644<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002645<pre>
2646 &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +00002647 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2648 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +00002649</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +00002650</div>
Chris Lattner00950542001-06-06 20:29:01 +00002651<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +00002652<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +00002653<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +00002654<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +00002655<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 +00002656</pre>
Chris Lattner261efe92003-11-25 01:02:51 +00002657<h5>Overview:</h5>
2658<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2659or of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +00002660<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002661
2662<p>The two arguments to the '<tt>or</tt>' instruction must be
2663<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2664values. Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +00002665<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +00002666<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +00002667<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +00002668<div style="align: center">
Chris Lattner261efe92003-11-25 01:02:51 +00002669<table border="1" cellspacing="0" cellpadding="4">
2670 <tbody>
2671 <tr>
2672 <td>In0</td>
2673 <td>In1</td>
2674 <td>Out</td>
2675 </tr>
2676 <tr>
2677 <td>0</td>
2678 <td>0</td>
2679 <td>0</td>
2680 </tr>
2681 <tr>
2682 <td>0</td>
2683 <td>1</td>
2684 <td>1</td>
2685 </tr>
2686 <tr>
2687 <td>1</td>
2688 <td>0</td>
2689 <td>1</td>
2690 </tr>
2691 <tr>
2692 <td>1</td>
2693 <td>1</td>
2694 <td>1</td>
2695 </tr>
2696 </tbody>
2697</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +00002698</div>
Chris Lattner00950542001-06-06 20:29:01 +00002699<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +00002700<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2701 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2702 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +00002703</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +00002704</div>
Chris Lattner00950542001-06-06 20:29:01 +00002705<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +00002706<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2707Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +00002708<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +00002709<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +00002710<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 +00002711</pre>
Chris Lattner00950542001-06-06 20:29:01 +00002712<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +00002713<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2714or of its two operands. The <tt>xor</tt> is used to implement the
2715"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner00950542001-06-06 20:29:01 +00002716<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002717<p>The two arguments to the '<tt>xor</tt>' instruction must be
2718<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2719values. Both arguments must have identical types.</p>
2720
Chris Lattner00950542001-06-06 20:29:01 +00002721<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00002722
Misha Brukman9d0919f2003-11-08 01:05:38 +00002723<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +00002724<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +00002725<div style="align: center">
Chris Lattner261efe92003-11-25 01:02:51 +00002726<table border="1" cellspacing="0" cellpadding="4">
2727 <tbody>
2728 <tr>
2729 <td>In0</td>
2730 <td>In1</td>
2731 <td>Out</td>
2732 </tr>
2733 <tr>
2734 <td>0</td>
2735 <td>0</td>
2736 <td>0</td>
2737 </tr>
2738 <tr>
2739 <td>0</td>
2740 <td>1</td>
2741 <td>1</td>
2742 </tr>
2743 <tr>
2744 <td>1</td>
2745 <td>0</td>
2746 <td>1</td>
2747 </tr>
2748 <tr>
2749 <td>1</td>
2750 <td>1</td>
2751 <td>0</td>
2752 </tr>
2753 </tbody>
2754</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +00002755</div>
Chris Lattner261efe92003-11-25 01:02:51 +00002756<p> </p>
Chris Lattner00950542001-06-06 20:29:01 +00002757<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +00002758<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2759 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2760 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2761 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +00002762</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +00002763</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +00002764
Chris Lattner00950542001-06-06 20:29:01 +00002765<!-- ======================================================================= -->
Chris Lattner2cbdc452005-11-06 08:02:57 +00002766<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +00002767 <a name="vectorops">Vector Operations</a>
2768</div>
2769
2770<div class="doc_text">
2771
2772<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen6f1cc772007-04-22 01:17:39 +00002773target-independent manner. These instructions cover the element-access and
Chris Lattner3df241e2006-04-08 23:07:04 +00002774vector-specific operations needed to process vectors effectively. While LLVM
2775does directly support these vector operations, many sophisticated algorithms
2776will want to use target-specific intrinsics to take full advantage of a specific
2777target.</p>
2778
2779</div>
2780
2781<!-- _______________________________________________________________________ -->
2782<div class="doc_subsubsection">
2783 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
2784</div>
2785
2786<div class="doc_text">
2787
2788<h5>Syntax:</h5>
2789
2790<pre>
Reid Spencerca86e162006-12-31 07:07:53 +00002791 &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 +00002792</pre>
2793
2794<h5>Overview:</h5>
2795
2796<p>
2797The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer485bad12007-02-15 03:07:05 +00002798element from a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +00002799</p>
2800
2801
2802<h5>Arguments:</h5>
2803
2804<p>
2805The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +00002806value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattner3df241e2006-04-08 23:07:04 +00002807an index indicating the position from which to extract the element.
2808The index may be a variable.</p>
2809
2810<h5>Semantics:</h5>
2811
2812<p>
2813The result is a scalar of the same type as the element type of
2814<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
2815<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
2816results are undefined.
2817</p>
2818
2819<h5>Example:</h5>
2820
2821<pre>
Reid Spencerca86e162006-12-31 07:07:53 +00002822 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +00002823</pre>
2824</div>
2825
2826
2827<!-- _______________________________________________________________________ -->
2828<div class="doc_subsubsection">
2829 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
2830</div>
2831
2832<div class="doc_text">
2833
2834<h5>Syntax:</h5>
2835
2836<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +00002837 &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 +00002838</pre>
2839
2840<h5>Overview:</h5>
2841
2842<p>
2843The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer485bad12007-02-15 03:07:05 +00002844element into a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +00002845</p>
2846
2847
2848<h5>Arguments:</h5>
2849
2850<p>
2851The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +00002852value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattner3df241e2006-04-08 23:07:04 +00002853scalar value whose type must equal the element type of the first
2854operand. The third operand is an index indicating the position at
2855which to insert the value. The index may be a variable.</p>
2856
2857<h5>Semantics:</h5>
2858
2859<p>
Reid Spencer485bad12007-02-15 03:07:05 +00002860The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattner3df241e2006-04-08 23:07:04 +00002861element values are those of <tt>val</tt> except at position
2862<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
2863exceeds the length of <tt>val</tt>, the results are undefined.
2864</p>
2865
2866<h5>Example:</h5>
2867
2868<pre>
Reid Spencerca86e162006-12-31 07:07:53 +00002869 %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 +00002870</pre>
2871</div>
2872
2873<!-- _______________________________________________________________________ -->
2874<div class="doc_subsubsection">
2875 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
2876</div>
2877
2878<div class="doc_text">
2879
2880<h5>Syntax:</h5>
2881
2882<pre>
Reid Spencerca86e162006-12-31 07:07:53 +00002883 &lt;result&gt; = shufflevector &lt;n x &lt;ty&gt;&gt; &lt;v1&gt;, &lt;n x &lt;ty&gt;&gt; &lt;v2&gt;, &lt;n x i32&gt; &lt;mask&gt; <i>; yields &lt;n x &lt;ty&gt;&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +00002884</pre>
2885
2886<h5>Overview:</h5>
2887
2888<p>
2889The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
2890from two input vectors, returning a vector of the same type.
2891</p>
2892
2893<h5>Arguments:</h5>
2894
2895<p>
2896The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
2897with types that match each other and types that match the result of the
2898instruction. The third argument is a shuffle mask, which has the same number
Reid Spencerca86e162006-12-31 07:07:53 +00002899of elements as the other vector type, but whose element type is always 'i32'.
Chris Lattner3df241e2006-04-08 23:07:04 +00002900</p>
2901
2902<p>
2903The shuffle mask operand is required to be a constant vector with either
2904constant integer or undef values.
2905</p>
2906
2907<h5>Semantics:</h5>
2908
2909<p>
2910The elements of the two input vectors are numbered from left to right across
2911both of the vectors. The shuffle mask operand specifies, for each element of
2912the result vector, which element of the two input registers the result element
2913gets. The element selector may be undef (meaning "don't care") and the second
2914operand may be undef if performing a shuffle from only one vector.
2915</p>
2916
2917<h5>Example:</h5>
2918
2919<pre>
Reid Spencerca86e162006-12-31 07:07:53 +00002920 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +00002921 &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 +00002922 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
2923 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i> - Identity shuffle.
Chris Lattner3df241e2006-04-08 23:07:04 +00002924</pre>
2925</div>
2926
Tanya Lattner09474292006-04-14 19:24:33 +00002927
Chris Lattner3df241e2006-04-08 23:07:04 +00002928<!-- ======================================================================= -->
2929<div class="doc_subsection">
Dan Gohmana334d5f2008-05-12 23:51:09 +00002930 <a name="aggregateops">Aggregate Operations</a>
2931</div>
2932
2933<div class="doc_text">
2934
2935<p>LLVM supports several instructions for working with aggregate values.
2936</p>
2937
2938</div>
2939
2940<!-- _______________________________________________________________________ -->
2941<div class="doc_subsubsection">
2942 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
2943</div>
2944
2945<div class="doc_text">
2946
2947<h5>Syntax:</h5>
2948
2949<pre>
2950 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
2951</pre>
2952
2953<h5>Overview:</h5>
2954
2955<p>
Dan Gohmanc3dac5c2008-05-13 18:16:06 +00002956The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
2957or array element from an aggregate value.
Dan Gohmana334d5f2008-05-12 23:51:09 +00002958</p>
2959
2960
2961<h5>Arguments:</h5>
2962
2963<p>
2964The first operand of an '<tt>extractvalue</tt>' instruction is a
2965value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohmanc3dac5c2008-05-13 18:16:06 +00002966type. The operands are constant indices to specify which value to extract
Dan Gohman81a0c0b2008-05-31 00:58:22 +00002967in a similar manner as indices in a
Dan Gohmana334d5f2008-05-12 23:51:09 +00002968'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
2969</p>
2970
2971<h5>Semantics:</h5>
2972
2973<p>
2974The result is the value at the position in the aggregate specified by
2975the index operands.
2976</p>
2977
2978<h5>Example:</h5>
2979
2980<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +00002981 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +00002982</pre>
2983</div>
2984
2985
2986<!-- _______________________________________________________________________ -->
2987<div class="doc_subsubsection">
2988 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
2989</div>
2990
2991<div class="doc_text">
2992
2993<h5>Syntax:</h5>
2994
2995<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +00002996 &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 +00002997</pre>
2998
2999<h5>Overview:</h5>
3000
3001<p>
3002The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohmanc3dac5c2008-05-13 18:16:06 +00003003into a struct field or array element in an aggregate.
Dan Gohmana334d5f2008-05-12 23:51:09 +00003004</p>
3005
3006
3007<h5>Arguments:</h5>
3008
3009<p>
3010The first operand of an '<tt>insertvalue</tt>' instruction is a
3011value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
3012The second operand is a first-class value to insert.
Dan Gohmanc4b49eb2008-05-23 21:53:15 +00003013The following operands are constant indices
Dan Gohman81a0c0b2008-05-31 00:58:22 +00003014indicating the position at which to insert the value in a similar manner as
Dan Gohmanc3dac5c2008-05-13 18:16:06 +00003015indices in a
Dan Gohmana334d5f2008-05-12 23:51:09 +00003016'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3017The value to insert must have the same type as the value identified
Dan Gohmanc3dac5c2008-05-13 18:16:06 +00003018by the indices.
Dan Gohmana334d5f2008-05-12 23:51:09 +00003019
3020<h5>Semantics:</h5>
3021
3022<p>
3023The result is an aggregate of the same type as <tt>val</tt>. Its
3024value is that of <tt>val</tt> except that the value at the position
Dan Gohmanc3dac5c2008-05-13 18:16:06 +00003025specified by the indices is that of <tt>elt</tt>.
Dan Gohmana334d5f2008-05-12 23:51:09 +00003026</p>
3027
3028<h5>Example:</h5>
3029
3030<pre>
Dan Gohman52bb2db2008-06-23 15:26:37 +00003031 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +00003032</pre>
3033</div>
3034
3035
3036<!-- ======================================================================= -->
3037<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +00003038 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003039</div>
3040
Misha Brukman9d0919f2003-11-08 01:05:38 +00003041<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +00003042
Chris Lattner261efe92003-11-25 01:02:51 +00003043<p>A key design point of an SSA-based representation is how it
3044represents memory. In LLVM, no memory locations are in SSA form, which
3045makes things very simple. This section describes how to read, write,
John Criswell9e2485c2004-12-10 15:51:16 +00003046allocate, and free memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003047
Misha Brukman9d0919f2003-11-08 01:05:38 +00003048</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003049
Chris Lattner00950542001-06-06 20:29:01 +00003050<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +00003051<div class="doc_subsubsection">
3052 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3053</div>
3054
Misha Brukman9d0919f2003-11-08 01:05:38 +00003055<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +00003056
Chris Lattner00950542001-06-06 20:29:01 +00003057<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003058
3059<pre>
Reid Spencerca86e162006-12-31 07:07:53 +00003060 &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 +00003061</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003062
Chris Lattner00950542001-06-06 20:29:01 +00003063<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003064
Chris Lattner261efe92003-11-25 01:02:51 +00003065<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb303dae92007-12-17 01:00:21 +00003066heap and returns a pointer to it. The object is always allocated in the generic
3067address space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003068
Chris Lattner00950542001-06-06 20:29:01 +00003069<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003070
3071<p>The '<tt>malloc</tt>' instruction allocates
3072<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswell6e4ca612004-02-24 16:13:56 +00003073bytes of memory from the operating system and returns a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +00003074appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif1acd2ee2008-02-09 22:24:34 +00003075number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner4316dec2008-04-02 00:38:26 +00003076If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greif1acd2ee2008-02-09 22:24:34 +00003077be aligned to at least that boundary. If not specified, or if zero, the target can
3078choose to align the allocation on any convenient boundary.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003079
Misha Brukman9d0919f2003-11-08 01:05:38 +00003080<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003081
Chris Lattner00950542001-06-06 20:29:01 +00003082<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003083
Chris Lattner261efe92003-11-25 01:02:51 +00003084<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Chris Lattner72ed2002008-04-19 21:01:16 +00003085a pointer is returned. The result of a zero byte allocattion is undefined. The
3086result is null if there is insufficient memory available.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +00003087
Chris Lattner2cbdc452005-11-06 08:02:57 +00003088<h5>Example:</h5>
3089
3090<pre>
Reid Spencerca86e162006-12-31 07:07:53 +00003091 %array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003092
Bill Wendlingaac388b2007-05-29 09:42:13 +00003093 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3094 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3095 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3096 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3097 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner00950542001-06-06 20:29:01 +00003098</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +00003099</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003100
Chris Lattner00950542001-06-06 20:29:01 +00003101<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +00003102<div class="doc_subsubsection">
3103 <a name="i_free">'<tt>free</tt>' Instruction</a>
3104</div>
3105
Misha Brukman9d0919f2003-11-08 01:05:38 +00003106<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +00003107
Chris Lattner00950542001-06-06 20:29:01 +00003108<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003109
3110<pre>
3111 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner00950542001-06-06 20:29:01 +00003112</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003113
Chris Lattner00950542001-06-06 20:29:01 +00003114<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003115
Chris Lattner261efe92003-11-25 01:02:51 +00003116<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswellc1f786c2005-05-13 22:25:59 +00003117memory heap to be reallocated in the future.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003118
Chris Lattner00950542001-06-06 20:29:01 +00003119<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003120
Chris Lattner261efe92003-11-25 01:02:51 +00003121<p>'<tt>value</tt>' shall be a pointer value that points to a value
3122that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
3123instruction.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003124
Chris Lattner00950542001-06-06 20:29:01 +00003125<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003126
John Criswell9e2485c2004-12-10 15:51:16 +00003127<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattnere0db56d2008-04-19 22:41:32 +00003128after this instruction executes. If the pointer is null, the operation
3129is a noop.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003130
Chris Lattner00950542001-06-06 20:29:01 +00003131<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003132
3133<pre>
Reid Spencerca86e162006-12-31 07:07:53 +00003134 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
3135 free [4 x i8]* %array
Chris Lattner00950542001-06-06 20:29:01 +00003136</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +00003137</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003138
Chris Lattner00950542001-06-06 20:29:01 +00003139<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +00003140<div class="doc_subsubsection">
3141 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3142</div>
3143
Misha Brukman9d0919f2003-11-08 01:05:38 +00003144<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +00003145
Chris Lattner00950542001-06-06 20:29:01 +00003146<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003147
3148<pre>
Reid Spencerca86e162006-12-31 07:07:53 +00003149 &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 +00003150</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003151
Chris Lattner00950542001-06-06 20:29:01 +00003152<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003153
Jeff Cohen6f1cc772007-04-22 01:17:39 +00003154<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
3155currently executing function, to be automatically released when this function
Christopher Lamb303dae92007-12-17 01:00:21 +00003156returns to its caller. The object is always allocated in the generic address
3157space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003158
Chris Lattner00950542001-06-06 20:29:01 +00003159<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003160
John Criswell9e2485c2004-12-10 15:51:16 +00003161<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner261efe92003-11-25 01:02:51 +00003162bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif1acd2ee2008-02-09 22:24:34 +00003163appropriate type to the program. If "NumElements" is specified, it is the
3164number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner4316dec2008-04-02 00:38:26 +00003165If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greif1acd2ee2008-02-09 22:24:34 +00003166to be aligned to at least that boundary. If not specified, or if zero, the target
3167can choose to align the allocation on any convenient boundary.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003168
Misha Brukman9d0919f2003-11-08 01:05:38 +00003169<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003170
Chris Lattner00950542001-06-06 20:29:01 +00003171<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003172
Chris Lattner72ed2002008-04-19 21:01:16 +00003173<p>Memory is allocated; a pointer is returned. The operation is undefiend if
3174there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner261efe92003-11-25 01:02:51 +00003175memory is automatically released when the function returns. The '<tt>alloca</tt>'
3176instruction is commonly used to represent automatic variables that must
3177have an address available. When the function returns (either with the <tt><a
John Criswelldae2e932005-05-12 16:55:34 +00003178 href="#i_ret">ret</a></tt> or <tt><a href="#i_unwind">unwind</a></tt>
Chris Lattner4316dec2008-04-02 00:38:26 +00003179instructions), the memory is reclaimed. Allocating zero bytes
3180is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003181
Chris Lattner00950542001-06-06 20:29:01 +00003182<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003183
3184<pre>
Reid Spencerca86e162006-12-31 07:07:53 +00003185 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling2f7a8b02007-05-29 09:04:49 +00003186 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3187 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencerca86e162006-12-31 07:07:53 +00003188 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +00003189</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +00003190</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +00003191
Chris Lattner00950542001-06-06 20:29:01 +00003192<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +00003193<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3194Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +00003195<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +00003196<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +00003197<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 +00003198<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +00003199<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +00003200<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +00003201<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell0ec250c2005-10-24 16:17:18 +00003202address from which to load. The pointer must point to a <a
Chris Lattnere53e5082004-06-03 22:57:15 +00003203 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell0ec250c2005-10-24 16:17:18 +00003204marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner261efe92003-11-25 01:02:51 +00003205the number or order of execution of this <tt>load</tt> with other
3206volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3207instructions. </p>
Chris Lattnera31d1d72008-01-06 21:04:43 +00003208<p>
Chris Lattner4316dec2008-04-02 00:38:26 +00003209The optional constant "align" argument specifies the alignment of the operation
Chris Lattnera31d1d72008-01-06 21:04:43 +00003210(that is, the alignment of the memory address). A value of 0 or an
3211omitted "align" argument means that the operation has the preferential
3212alignment for the target. It is the responsibility of the code emitter
3213to ensure that the alignment information is correct. Overestimating
3214the alignment results in an undefined behavior. Underestimating the
3215alignment may produce less efficient code. An alignment of 1 is always
3216safe.
3217</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +00003218<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +00003219<p>The location of memory pointed to is loaded.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +00003220<h5>Examples:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +00003221<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner261efe92003-11-25 01:02:51 +00003222 <a
Reid Spencerca86e162006-12-31 07:07:53 +00003223 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
3224 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +00003225</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +00003226</div>
Chris Lattner2b7d3202002-05-06 03:03:22 +00003227<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +00003228<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3229Instruction</a> </div>
Reid Spencer035ab572006-11-09 21:18:01 +00003230<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +00003231<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +00003232<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
3233 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 +00003234</pre>
Chris Lattner2b7d3202002-05-06 03:03:22 +00003235<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +00003236<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +00003237<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +00003238<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen6f1cc772007-04-22 01:17:39 +00003239to 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 +00003240operand must be a pointer to the <a href="#t_firstclass">first class</a> type
3241of the '<tt>&lt;value&gt;</tt>'
John Criswellc1f786c2005-05-13 22:25:59 +00003242operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner261efe92003-11-25 01:02:51 +00003243optimizer is not allowed to modify the number or order of execution of
3244this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
3245 href="#i_store">store</a></tt> instructions.</p>
Chris Lattnera31d1d72008-01-06 21:04:43 +00003246<p>
Chris Lattner4316dec2008-04-02 00:38:26 +00003247The optional constant "align" argument specifies the alignment of the operation
Chris Lattnera31d1d72008-01-06 21:04:43 +00003248(that is, the alignment of the memory address). A value of 0 or an
3249omitted "align" argument means that the operation has the preferential
3250alignment for the target. It is the responsibility of the code emitter
3251to ensure that the alignment information is correct. Overestimating
3252the alignment results in an undefined behavior. Underestimating the
3253alignment may produce less efficient code. An alignment of 1 is always
3254safe.
3255</p>
Chris Lattner261efe92003-11-25 01:02:51 +00003256<h5>Semantics:</h5>
3257<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
3258at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +00003259<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +00003260<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +00003261 store i32 3, i32* %ptr <i>; yields {void}</i>
3262 %val = <a href="#i_load">load</a> i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +00003263</pre>
Reid Spencer47ce1792006-11-09 21:15:49 +00003264</div>
3265
Chris Lattner2b7d3202002-05-06 03:03:22 +00003266<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +00003267<div class="doc_subsubsection">
3268 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3269</div>
3270
Misha Brukman9d0919f2003-11-08 01:05:38 +00003271<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +00003272<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +00003273<pre>
3274 &lt;result&gt; = getelementptr &lt;ty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
3275</pre>
3276
Chris Lattner7faa8832002-04-14 06:13:44 +00003277<h5>Overview:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +00003278
3279<p>
3280The '<tt>getelementptr</tt>' instruction is used to get the address of a
3281subelement of an aggregate data structure.</p>
3282
Chris Lattner7faa8832002-04-14 06:13:44 +00003283<h5>Arguments:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +00003284
Reid Spencer85f5b5b2006-12-04 21:29:24 +00003285<p>This instruction takes a list of integer operands that indicate what
Chris Lattnerf74d5c72004-04-05 01:30:49 +00003286elements of the aggregate object to index to. The actual types of the arguments
3287provided depend on the type of the first pointer argument. The
3288'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswellfc6b8952005-05-16 16:17:45 +00003289levels of a structure or to a specific index in an array. When indexing into a
Reid Spencerca86e162006-12-31 07:07:53 +00003290structure, only <tt>i32</tt> integer constants are allowed. When indexing
Chris Lattner05d67092008-04-24 05:59:56 +00003291into an array or pointer, only integers of 32 or 64 bits are allowed; 32-bit
3292values will be sign extended to 64-bits if required.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +00003293
Chris Lattner261efe92003-11-25 01:02:51 +00003294<p>For example, let's consider a C code fragment and how it gets
3295compiled to LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +00003296
Bill Wendling2f7a8b02007-05-29 09:04:49 +00003297<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +00003298<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +00003299struct RT {
3300 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +00003301 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +00003302 char C;
3303};
3304struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +00003305 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +00003306 double Y;
3307 struct RT Z;
3308};
Chris Lattnerf74d5c72004-04-05 01:30:49 +00003309
Chris Lattnercabc8462007-05-29 15:43:56 +00003310int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +00003311 return &amp;s[1].Z.B[5][13];
3312}
Chris Lattnerf74d5c72004-04-05 01:30:49 +00003313</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +00003314</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +00003315
Misha Brukman9d0919f2003-11-08 01:05:38 +00003316<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +00003317
Bill Wendling2f7a8b02007-05-29 09:04:49 +00003318<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +00003319<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +00003320%RT = type { i8 , [10 x [20 x i32]], i8 }
3321%ST = type { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +00003322
Bill Wendling2f7a8b02007-05-29 09:04:49 +00003323define i32* %foo(%ST* %s) {
3324entry:
3325 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3326 ret i32* %reg
3327}
Chris Lattnerf74d5c72004-04-05 01:30:49 +00003328</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +00003329</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +00003330
Chris Lattner7faa8832002-04-14 06:13:44 +00003331<h5>Semantics:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +00003332
3333<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswellc1f786c2005-05-13 22:25:59 +00003334on the pointer type that is being indexed into. <a href="#t_pointer">Pointer</a>
Reid Spencer85f5b5b2006-12-04 21:29:24 +00003335and <a href="#t_array">array</a> types can use a 32-bit or 64-bit
Reid Spencer42ddd842006-12-03 16:53:48 +00003336<a href="#t_integer">integer</a> type but the value will always be sign extended
Chris Lattner4316dec2008-04-02 00:38:26 +00003337to 64-bits. <a href="#t_struct">Structure</a> and <a href="#t_pstruct">packed
3338structure</a> types require <tt>i32</tt> <b>constants</b>.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +00003339
Misha Brukman9d0919f2003-11-08 01:05:38 +00003340<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Reid Spencerca86e162006-12-31 07:07:53 +00003341type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattnerf74d5c72004-04-05 01:30:49 +00003342}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerca86e162006-12-31 07:07:53 +00003343the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3344i8 }</tt>' type, another structure. The third index indexes into the second
3345element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattnerf74d5c72004-04-05 01:30:49 +00003346array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerca86e162006-12-31 07:07:53 +00003347'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
3348to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +00003349
Chris Lattner261efe92003-11-25 01:02:51 +00003350<p>Note that it is perfectly legal to index partially through a
3351structure, returning a pointer to an inner element. Because of this,
3352the LLVM code for the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +00003353
3354<pre>
Reid Spencerca86e162006-12-31 07:07:53 +00003355 define i32* %foo(%ST* %s) {
3356 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +00003357 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3358 %t3 = getelementptr %RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i>
Reid Spencerca86e162006-12-31 07:07:53 +00003359 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3360 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
3361 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +00003362 }
Chris Lattner6536cfe2002-05-06 22:08:29 +00003363</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +00003364
3365<p>Note that it is undefined to access an array out of bounds: array and
3366pointer indexes must always be within the defined bounds of the array type.
Chris Lattner05d67092008-04-24 05:59:56 +00003367The one exception for this rule is zero length arrays. These arrays are
Chris Lattnere67a9512005-06-24 17:22:57 +00003368defined to be accessible as variable length arrays, which requires access
3369beyond the zero'th element.</p>
3370
Chris Lattner884a9702006-08-15 00:45:58 +00003371<p>The getelementptr instruction is often confusing. For some more insight
3372into how it works, see <a href="GetElementPtr.html">the getelementptr
3373FAQ</a>.</p>
3374
Chris Lattner7faa8832002-04-14 06:13:44 +00003375<h5>Example:</h5>
Chris Lattnere67a9512005-06-24 17:22:57 +00003376
Chris Lattnerf74d5c72004-04-05 01:30:49 +00003377<pre>
Reid Spencerca86e162006-12-31 07:07:53 +00003378 <i>; yields [12 x i8]*:aptr</i>
3379 %aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattnerf74d5c72004-04-05 01:30:49 +00003380</pre>
Chris Lattnerf74d5c72004-04-05 01:30:49 +00003381</div>
Reid Spencer47ce1792006-11-09 21:15:49 +00003382
Chris Lattner00950542001-06-06 20:29:01 +00003383<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +00003384<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +00003385</div>
Misha Brukman9d0919f2003-11-08 01:05:38 +00003386<div class="doc_text">
Reid Spencer2fd21e62006-11-08 01:18:52 +00003387<p>The instructions in this category are the conversion instructions (casting)
3388which all take a single operand and a type. They perform various bit conversions
3389on the operand.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +00003390</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +00003391
Chris Lattner6536cfe2002-05-06 22:08:29 +00003392<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +00003393<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003394 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
3395</div>
3396<div class="doc_text">
3397
3398<h5>Syntax:</h5>
3399<pre>
3400 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3401</pre>
3402
3403<h5>Overview:</h5>
3404<p>
3405The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
3406</p>
3407
3408<h5>Arguments:</h5>
3409<p>
3410The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
3411be an <a href="#t_integer">integer</a> type, and a type that specifies the size
Chris Lattner3b19d652007-01-15 01:54:13 +00003412and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencerd4448792006-11-09 23:03:26 +00003413type. The bit size of <tt>value</tt> must be larger than the bit size of
3414<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003415
3416<h5>Semantics:</h5>
3417<p>
3418The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencerd4448792006-11-09 23:03:26 +00003419and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
3420larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
3421It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003422
3423<h5>Example:</h5>
3424<pre>
Reid Spencerca86e162006-12-31 07:07:53 +00003425 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +00003426 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
3427 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003428</pre>
3429</div>
3430
3431<!-- _______________________________________________________________________ -->
3432<div class="doc_subsubsection">
3433 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
3434</div>
3435<div class="doc_text">
3436
3437<h5>Syntax:</h5>
3438<pre>
3439 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3440</pre>
3441
3442<h5>Overview:</h5>
3443<p>The '<tt>zext</tt>' instruction zero extends its operand to type
3444<tt>ty2</tt>.</p>
3445
3446
3447<h5>Arguments:</h5>
3448<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Chris Lattner3b19d652007-01-15 01:54:13 +00003449<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3450also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +00003451<tt>value</tt> must be smaller than the bit size of the destination type,
3452<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003453
3454<h5>Semantics:</h5>
3455<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Chris Lattnerd1d25172007-05-24 19:13:27 +00003456bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003457
Reid Spencerb5929522007-01-12 15:46:11 +00003458<p>When zero extending from i1, the result will always be either 0 or 1.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003459
3460<h5>Example:</h5>
3461<pre>
Reid Spencerca86e162006-12-31 07:07:53 +00003462 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +00003463 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003464</pre>
3465</div>
3466
3467<!-- _______________________________________________________________________ -->
3468<div class="doc_subsubsection">
3469 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3470</div>
3471<div class="doc_text">
3472
3473<h5>Syntax:</h5>
3474<pre>
3475 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3476</pre>
3477
3478<h5>Overview:</h5>
3479<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3480
3481<h5>Arguments:</h5>
3482<p>
3483The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattner3b19d652007-01-15 01:54:13 +00003484<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3485also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +00003486<tt>value</tt> must be smaller than the bit size of the destination type,
3487<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003488
3489<h5>Semantics:</h5>
3490<p>
3491The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3492bit (highest order bit) of the <tt>value</tt> until it reaches the bit size of
Chris Lattnerd1d25172007-05-24 19:13:27 +00003493the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003494
Reid Spencerc78f3372007-01-12 03:35:51 +00003495<p>When sign extending from i1, the extension always results in -1 or 0.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003496
3497<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003498<pre>
Reid Spencerca86e162006-12-31 07:07:53 +00003499 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +00003500 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003501</pre>
3502</div>
3503
3504<!-- _______________________________________________________________________ -->
3505<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +00003506 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3507</div>
3508
3509<div class="doc_text">
3510
3511<h5>Syntax:</h5>
3512
3513<pre>
3514 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3515</pre>
3516
3517<h5>Overview:</h5>
3518<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3519<tt>ty2</tt>.</p>
3520
3521
3522<h5>Arguments:</h5>
3523<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3524 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3525cast it to. The size of <tt>value</tt> must be larger than the size of
3526<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3527<i>no-op cast</i>.</p>
3528
3529<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +00003530<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3531<a href="#t_floating">floating point</a> type to a smaller
3532<a href="#t_floating">floating point</a> type. If the value cannot fit within
3533the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +00003534
3535<h5>Example:</h5>
3536<pre>
3537 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3538 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3539</pre>
3540</div>
3541
3542<!-- _______________________________________________________________________ -->
3543<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003544 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3545</div>
3546<div class="doc_text">
3547
3548<h5>Syntax:</h5>
3549<pre>
3550 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3551</pre>
3552
3553<h5>Overview:</h5>
3554<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3555floating point value.</p>
3556
3557<h5>Arguments:</h5>
3558<p>The '<tt>fpext</tt>' instruction takes a
3559<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencerd4448792006-11-09 23:03:26 +00003560and a <a href="#t_floating">floating point</a> type to cast it to. The source
3561type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003562
3563<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +00003564<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands8036ca42007-03-30 12:22:09 +00003565<a href="#t_floating">floating point</a> type to a larger
3566<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencerd4448792006-11-09 23:03:26 +00003567used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5c0ef472006-11-11 23:08:07 +00003568<tt>bitcast</tt> to make a <i>no-op cast</i> for a floating point cast.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003569
3570<h5>Example:</h5>
3571<pre>
3572 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3573 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3574</pre>
3575</div>
3576
3577<!-- _______________________________________________________________________ -->
3578<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +00003579 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003580</div>
3581<div class="doc_text">
3582
3583<h5>Syntax:</h5>
3584<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +00003585 &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 +00003586</pre>
3587
3588<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +00003589<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003590unsigned integer equivalent of type <tt>ty2</tt>.
3591</p>
3592
3593<h5>Arguments:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +00003594<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
Nate Begemanb348d182007-11-17 03:58:34 +00003595scalar or vector <a href="#t_floating">floating point</a> value, and a type
3596to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3597type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3598vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003599
3600<h5>Semantics:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +00003601<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003602<a href="#t_floating">floating point</a> operand into the nearest (rounding
3603towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3604the results are undefined.</p>
3605
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003606<h5>Example:</h5>
3607<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +00003608 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +00003609 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer1539a1c2007-07-31 14:40:14 +00003610 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003611</pre>
3612</div>
3613
3614<!-- _______________________________________________________________________ -->
3615<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +00003616 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003617</div>
3618<div class="doc_text">
3619
3620<h5>Syntax:</h5>
3621<pre>
Reid Spencerd4448792006-11-09 23:03:26 +00003622 &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 +00003623</pre>
3624
3625<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +00003626<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003627<a href="#t_floating">floating point</a> <tt>value</tt> to type <tt>ty2</tt>.
Chris Lattnercc37aae2004-03-12 05:50:16 +00003628</p>
3629
Chris Lattner6536cfe2002-05-06 22:08:29 +00003630<h5>Arguments:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +00003631<p> The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
Nate Begemanb348d182007-11-17 03:58:34 +00003632scalar or vector <a href="#t_floating">floating point</a> value, and a type
3633to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3634type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3635vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +00003636
Chris Lattner6536cfe2002-05-06 22:08:29 +00003637<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +00003638<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003639<a href="#t_floating">floating point</a> operand into the nearest (rounding
3640towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3641the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +00003642
Chris Lattner33ba0d92001-07-09 00:26:23 +00003643<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +00003644<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +00003645 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +00003646 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerca86e162006-12-31 07:07:53 +00003647 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003648</pre>
3649</div>
3650
3651<!-- _______________________________________________________________________ -->
3652<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +00003653 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003654</div>
3655<div class="doc_text">
3656
3657<h5>Syntax:</h5>
3658<pre>
Reid Spencerd4448792006-11-09 23:03:26 +00003659 &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 +00003660</pre>
3661
3662<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +00003663<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003664integer and converts that value to the <tt>ty2</tt> type.</p>
3665
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003666<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +00003667<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3668scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3669to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3670type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3671floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003672
3673<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +00003674<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003675integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +00003676the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003677
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003678<h5>Example:</h5>
3679<pre>
Reid Spencerca86e162006-12-31 07:07:53 +00003680 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohenb627eab2007-04-29 01:07:00 +00003681 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003682</pre>
3683</div>
3684
3685<!-- _______________________________________________________________________ -->
3686<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +00003687 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003688</div>
3689<div class="doc_text">
3690
3691<h5>Syntax:</h5>
3692<pre>
Reid Spencerd4448792006-11-09 23:03:26 +00003693 &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 +00003694</pre>
3695
3696<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +00003697<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003698integer and converts that value to the <tt>ty2</tt> type.</p>
3699
3700<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +00003701<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3702scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3703to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3704type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3705floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003706
3707<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +00003708<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003709integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +00003710the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003711
3712<h5>Example:</h5>
3713<pre>
Reid Spencerca86e162006-12-31 07:07:53 +00003714 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohenb627eab2007-04-29 01:07:00 +00003715 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003716</pre>
3717</div>
3718
3719<!-- _______________________________________________________________________ -->
3720<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +00003721 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3722</div>
3723<div class="doc_text">
3724
3725<h5>Syntax:</h5>
3726<pre>
3727 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3728</pre>
3729
3730<h5>Overview:</h5>
3731<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3732the integer type <tt>ty2</tt>.</p>
3733
3734<h5>Arguments:</h5>
3735<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands8036ca42007-03-30 12:22:09 +00003736must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Reid Spencer72679252006-11-11 21:00:47 +00003737<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
3738
3739<h5>Semantics:</h5>
3740<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3741<tt>ty2</tt> by interpreting the pointer value as an integer and either
3742truncating or zero extending that value to the size of the integer type. If
3743<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3744<tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
Jeff Cohenb627eab2007-04-29 01:07:00 +00003745are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3746change.</p>
Reid Spencer72679252006-11-11 21:00:47 +00003747
3748<h5>Example:</h5>
3749<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +00003750 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3751 %Y = ptrtoint i32* %x to i64 <i>; yields zero extension on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +00003752</pre>
3753</div>
3754
3755<!-- _______________________________________________________________________ -->
3756<div class="doc_subsubsection">
3757 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3758</div>
3759<div class="doc_text">
3760
3761<h5>Syntax:</h5>
3762<pre>
3763 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3764</pre>
3765
3766<h5>Overview:</h5>
3767<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
3768a pointer type, <tt>ty2</tt>.</p>
3769
3770<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +00003771<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencer72679252006-11-11 21:00:47 +00003772value to cast, and a type to cast it to, which must be a
Anton Korobeynikov7f705592007-01-12 19:20:47 +00003773<a href="#t_pointer">pointer</a> type.
Reid Spencer72679252006-11-11 21:00:47 +00003774
3775<h5>Semantics:</h5>
3776<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
3777<tt>ty2</tt> by applying either a zero extension or a truncation depending on
3778the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
3779size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
3780the size of a pointer then a zero extension is done. If they are the same size,
3781nothing is done (<i>no-op cast</i>).</p>
3782
3783<h5>Example:</h5>
3784<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +00003785 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
3786 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
3787 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +00003788</pre>
3789</div>
3790
3791<!-- _______________________________________________________________________ -->
3792<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +00003793 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003794</div>
3795<div class="doc_text">
3796
3797<h5>Syntax:</h5>
3798<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +00003799 &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 +00003800</pre>
3801
3802<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00003803
Reid Spencer5c0ef472006-11-11 23:08:07 +00003804<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003805<tt>ty2</tt> without changing any bits.</p>
3806
3807<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00003808
Reid Spencer5c0ef472006-11-11 23:08:07 +00003809<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003810a first class value, and a type to cast it to, which must also be a <a
3811 href="#t_firstclass">first class</a> type. The bit sizes of <tt>value</tt>
Reid Spencer19b569f2007-01-09 20:08:58 +00003812and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattner5568e942008-05-20 20:48:21 +00003813type is a pointer, the destination type must also be a pointer. This
3814instruction supports bitwise conversion of vectors to integers and to vectors
3815of other types (as long as they have the same size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003816
3817<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +00003818<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer72679252006-11-11 21:00:47 +00003819<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
3820this conversion. The conversion is done as if the <tt>value</tt> had been
3821stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
3822converted to other pointer types with this instruction. To convert pointers to
3823other types, use the <a href="#i_inttoptr">inttoptr</a> or
3824<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +00003825
3826<h5>Example:</h5>
3827<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +00003828 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +00003829 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
3830 %Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner33ba0d92001-07-09 00:26:23 +00003831</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +00003832</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +00003833
Reid Spencer2fd21e62006-11-08 01:18:52 +00003834<!-- ======================================================================= -->
3835<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
3836<div class="doc_text">
3837<p>The instructions in this category are the "miscellaneous"
3838instructions, which defy better classification.</p>
3839</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +00003840
3841<!-- _______________________________________________________________________ -->
3842<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
3843</div>
3844<div class="doc_text">
3845<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +00003846<pre> &lt;result&gt; = icmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1}:result</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +00003847</pre>
3848<h5>Overview:</h5>
3849<p>The '<tt>icmp</tt>' instruction returns a boolean value based on comparison
Chris Lattner4316dec2008-04-02 00:38:26 +00003850of its two integer or pointer operands.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +00003851<h5>Arguments:</h5>
3852<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +00003853the condition code indicating the kind of comparison to perform. It is not
3854a value, just a keyword. The possible condition code are:
Reid Spencerf3a70a62006-11-18 21:50:54 +00003855<ol>
3856 <li><tt>eq</tt>: equal</li>
3857 <li><tt>ne</tt>: not equal </li>
3858 <li><tt>ugt</tt>: unsigned greater than</li>
3859 <li><tt>uge</tt>: unsigned greater or equal</li>
3860 <li><tt>ult</tt>: unsigned less than</li>
3861 <li><tt>ule</tt>: unsigned less or equal</li>
3862 <li><tt>sgt</tt>: signed greater than</li>
3863 <li><tt>sge</tt>: signed greater or equal</li>
3864 <li><tt>slt</tt>: signed less than</li>
3865 <li><tt>sle</tt>: signed less or equal</li>
3866</ol>
Chris Lattner3b19d652007-01-15 01:54:13 +00003867<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Reid Spencer350f8aa2007-01-04 05:19:58 +00003868<a href="#t_pointer">pointer</a> typed. They must also be identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +00003869<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +00003870<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to
Reid Spencerf3a70a62006-11-18 21:50:54 +00003871the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencerc78f3372007-01-12 03:35:51 +00003872yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerf3a70a62006-11-18 21:50:54 +00003873<ol>
3874 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
3875 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3876 </li>
3877 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
3878 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3879 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +00003880 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +00003881 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +00003882 <tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +00003883 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +00003884 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +00003885 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +00003886 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +00003887 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +00003888 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +00003889 <li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +00003890 <tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +00003891 <li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +00003892 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +00003893 <li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +00003894 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +00003895</ol>
3896<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohenb627eab2007-04-29 01:07:00 +00003897values are compared as if they were integers.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +00003898
3899<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +00003900<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
3901 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
3902 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
3903 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
3904 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
3905 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +00003906</pre>
3907</div>
3908
3909<!-- _______________________________________________________________________ -->
3910<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
3911</div>
3912<div class="doc_text">
3913<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +00003914<pre> &lt;result&gt; = fcmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1}:result</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +00003915</pre>
3916<h5>Overview:</h5>
3917<p>The '<tt>fcmp</tt>' instruction returns a boolean value based on comparison
3918of its floating point operands.</p>
3919<h5>Arguments:</h5>
3920<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +00003921the condition code indicating the kind of comparison to perform. It is not
3922a value, just a keyword. The possible condition code are:
Reid Spencerf3a70a62006-11-18 21:50:54 +00003923<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +00003924 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +00003925 <li><tt>oeq</tt>: ordered and equal</li>
3926 <li><tt>ogt</tt>: ordered and greater than </li>
3927 <li><tt>oge</tt>: ordered and greater than or equal</li>
3928 <li><tt>olt</tt>: ordered and less than </li>
3929 <li><tt>ole</tt>: ordered and less than or equal</li>
3930 <li><tt>one</tt>: ordered and not equal</li>
3931 <li><tt>ord</tt>: ordered (no nans)</li>
3932 <li><tt>ueq</tt>: unordered or equal</li>
3933 <li><tt>ugt</tt>: unordered or greater than </li>
3934 <li><tt>uge</tt>: unordered or greater than or equal</li>
3935 <li><tt>ult</tt>: unordered or less than </li>
3936 <li><tt>ule</tt>: unordered or less than or equal</li>
3937 <li><tt>une</tt>: unordered or not equal</li>
3938 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +00003939 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +00003940</ol>
Jeff Cohenb627eab2007-04-29 01:07:00 +00003941<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer93a49852006-12-06 07:08:07 +00003942<i>unordered</i> means that either operand may be a QNAN.</p>
Reid Spencer350f8aa2007-01-04 05:19:58 +00003943<p>The <tt>val1</tt> and <tt>val2</tt> arguments must be
3944<a href="#t_floating">floating point</a> typed. They must have identical
3945types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +00003946<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +00003947<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemanac80ade2008-05-12 19:01:56 +00003948according to the condition code given as <tt>cond</tt>. The comparison performed
3949always yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerf3a70a62006-11-18 21:50:54 +00003950<ol>
3951 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +00003952 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greiffb224a22008-08-07 21:46:00 +00003953 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +00003954 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greiffb224a22008-08-07 21:46:00 +00003955 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +00003956 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greiffb224a22008-08-07 21:46:00 +00003957 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +00003958 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greiffb224a22008-08-07 21:46:00 +00003959 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +00003960 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greiffb224a22008-08-07 21:46:00 +00003961 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +00003962 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greiffb224a22008-08-07 21:46:00 +00003963 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +00003964 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
3965 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greiffb224a22008-08-07 21:46:00 +00003966 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +00003967 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greiffb224a22008-08-07 21:46:00 +00003968 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +00003969 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greiffb224a22008-08-07 21:46:00 +00003970 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +00003971 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greiffb224a22008-08-07 21:46:00 +00003972 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +00003973 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greiffb224a22008-08-07 21:46:00 +00003974 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +00003975 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greiffb224a22008-08-07 21:46:00 +00003976 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +00003977 <li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +00003978 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
3979</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +00003980
3981<h5>Example:</h5>
3982<pre> &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
3983 &lt;result&gt; = icmp one float 4.0, 5.0 <i>; yields: result=true</i>
3984 &lt;result&gt; = icmp olt float 4.0, 5.0 <i>; yields: result=true</i>
3985 &lt;result&gt; = icmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
3986</pre>
3987</div>
3988
Reid Spencer2fd21e62006-11-08 01:18:52 +00003989<!-- _______________________________________________________________________ -->
Nate Begemanac80ade2008-05-12 19:01:56 +00003990<div class="doc_subsubsection">
3991 <a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
3992</div>
3993<div class="doc_text">
3994<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +00003995<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 +00003996</pre>
3997<h5>Overview:</h5>
3998<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
3999element-wise comparison of its two integer vector operands.</p>
4000<h5>Arguments:</h5>
4001<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
4002the condition code indicating the kind of comparison to perform. It is not
4003a value, just a keyword. The possible condition code are:
4004<ol>
4005 <li><tt>eq</tt>: equal</li>
4006 <li><tt>ne</tt>: not equal </li>
4007 <li><tt>ugt</tt>: unsigned greater than</li>
4008 <li><tt>uge</tt>: unsigned greater or equal</li>
4009 <li><tt>ult</tt>: unsigned less than</li>
4010 <li><tt>ule</tt>: unsigned less or equal</li>
4011 <li><tt>sgt</tt>: signed greater than</li>
4012 <li><tt>sge</tt>: signed greater or equal</li>
4013 <li><tt>slt</tt>: signed less than</li>
4014 <li><tt>sle</tt>: signed less or equal</li>
4015</ol>
4016<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
4017<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
4018<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +00004019<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemanac80ade2008-05-12 19:01:56 +00004020according to the condition code given as <tt>cond</tt>. The comparison yields a
4021<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
4022identical type as the values being compared. The most significant bit in each
4023element is 1 if the element-wise comparison evaluates to true, and is 0
4024otherwise. All other bits of the result are undefined. The condition codes
4025are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
4026instruction</a>.
4027
4028<h5>Example:</h5>
4029<pre>
Chris Lattner5568e942008-05-20 20:48:21 +00004030 &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>
4031 &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 +00004032</pre>
4033</div>
4034
4035<!-- _______________________________________________________________________ -->
4036<div class="doc_subsubsection">
4037 <a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
4038</div>
4039<div class="doc_text">
4040<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +00004041<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 +00004042<h5>Overview:</h5>
4043<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
4044element-wise comparison of its two floating point vector operands. The output
4045elements have the same width as the input elements.</p>
4046<h5>Arguments:</h5>
4047<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
4048the condition code indicating the kind of comparison to perform. It is not
4049a value, just a keyword. The possible condition code are:
4050<ol>
4051 <li><tt>false</tt>: no comparison, always returns false</li>
4052 <li><tt>oeq</tt>: ordered and equal</li>
4053 <li><tt>ogt</tt>: ordered and greater than </li>
4054 <li><tt>oge</tt>: ordered and greater than or equal</li>
4055 <li><tt>olt</tt>: ordered and less than </li>
4056 <li><tt>ole</tt>: ordered and less than or equal</li>
4057 <li><tt>one</tt>: ordered and not equal</li>
4058 <li><tt>ord</tt>: ordered (no nans)</li>
4059 <li><tt>ueq</tt>: unordered or equal</li>
4060 <li><tt>ugt</tt>: unordered or greater than </li>
4061 <li><tt>uge</tt>: unordered or greater than or equal</li>
4062 <li><tt>ult</tt>: unordered or less than </li>
4063 <li><tt>ule</tt>: unordered or less than or equal</li>
4064 <li><tt>une</tt>: unordered or not equal</li>
4065 <li><tt>uno</tt>: unordered (either nans)</li>
4066 <li><tt>true</tt>: no comparison, always returns true</li>
4067</ol>
4068<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
4069<a href="#t_floating">floating point</a> typed. They must also be identical
4070types.</p>
4071<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +00004072<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemanac80ade2008-05-12 19:01:56 +00004073according to the condition code given as <tt>cond</tt>. The comparison yields a
4074<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
4075an identical number of elements as the values being compared, and each element
4076having identical with to the width of the floating point elements. The most
4077significant bit in each element is 1 if the element-wise comparison evaluates to
4078true, and is 0 otherwise. All other bits of the result are undefined. The
4079condition codes are evaluated identically to the
4080<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.
4081
4082<h5>Example:</h5>
4083<pre>
Chris Lattner5568e942008-05-20 20:48:21 +00004084 &lt;result&gt; = vfcmp oeq &lt;2 x float&gt; &lt; float 4, float 0 &gt;, &lt; float 5, float 0 &gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0, i32 -1 &gt;</i>
4085 &lt;result&gt; = vfcmp ult &lt;2 x double&gt; &lt; double 1, double 2 &gt;, &lt; double 2, double 2&gt; <i>; yields: result=&lt;2 x i64&gt; &lt; i64 -1, i64 0 &gt;</i>
Nate Begemanac80ade2008-05-12 19:01:56 +00004086</pre>
4087</div>
4088
4089<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +00004090<div class="doc_subsubsection">
4091 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4092</div>
4093
Reid Spencer2fd21e62006-11-08 01:18:52 +00004094<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +00004095
Reid Spencer2fd21e62006-11-08 01:18:52 +00004096<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00004097
Reid Spencer2fd21e62006-11-08 01:18:52 +00004098<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
4099<h5>Overview:</h5>
4100<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
4101the SSA graph representing the function.</p>
4102<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00004103
Jeff Cohenb627eab2007-04-29 01:07:00 +00004104<p>The type of the incoming values is specified with the first type
Reid Spencer2fd21e62006-11-08 01:18:52 +00004105field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
4106as arguments, with one pair for each predecessor basic block of the
4107current block. Only values of <a href="#t_firstclass">first class</a>
4108type may be used as the value arguments to the PHI node. Only labels
4109may be used as the label arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +00004110
Reid Spencer2fd21e62006-11-08 01:18:52 +00004111<p>There must be no non-phi instructions between the start of a basic
4112block and the PHI instructions: i.e. PHI instructions must be first in
4113a basic block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +00004114
Reid Spencer2fd21e62006-11-08 01:18:52 +00004115<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00004116
Jeff Cohenb627eab2007-04-29 01:07:00 +00004117<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
4118specified by the pair corresponding to the predecessor basic block that executed
4119just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +00004120
Reid Spencer2fd21e62006-11-08 01:18:52 +00004121<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +00004122<pre>
4123Loop: ; Infinite loop that counts from 0 on up...
4124 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4125 %nextindvar = add i32 %indvar, 1
4126 br label %Loop
4127</pre>
Reid Spencer2fd21e62006-11-08 01:18:52 +00004128</div>
4129
Chris Lattnercc37aae2004-03-12 05:50:16 +00004130<!-- _______________________________________________________________________ -->
4131<div class="doc_subsubsection">
4132 <a name="i_select">'<tt>select</tt>' Instruction</a>
4133</div>
4134
4135<div class="doc_text">
4136
4137<h5>Syntax:</h5>
4138
4139<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +00004140 &lt;result&gt; = select i1 &lt;cond&gt;, &lt;ty&gt; &lt;val1&gt;, &lt;ty&gt; &lt;val2&gt; <i>; yields ty</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +00004141</pre>
4142
4143<h5>Overview:</h5>
4144
4145<p>
4146The '<tt>select</tt>' instruction is used to choose one value based on a
4147condition, without branching.
4148</p>
4149
4150
4151<h5>Arguments:</h5>
4152
4153<p>
Chris Lattner5568e942008-05-20 20:48:21 +00004154The '<tt>select</tt>' instruction requires an 'i1' value indicating the
4155condition, and two values of the same <a href="#t_firstclass">first class</a>
4156type. If the val1/val2 are vectors, the entire vectors are selected, not
4157individual elements.
Chris Lattnercc37aae2004-03-12 05:50:16 +00004158</p>
4159
4160<h5>Semantics:</h5>
4161
4162<p>
Chris Lattner5568e942008-05-20 20:48:21 +00004163If the i1 condition evaluates is 1, the instruction returns the first
John Criswellfc6b8952005-05-16 16:17:45 +00004164value argument; otherwise, it returns the second value argument.
Chris Lattnercc37aae2004-03-12 05:50:16 +00004165</p>
4166
4167<h5>Example:</h5>
4168
4169<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +00004170 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +00004171</pre>
4172</div>
4173
Robert Bocchino05ccd702006-01-15 20:48:27 +00004174
4175<!-- _______________________________________________________________________ -->
4176<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +00004177 <a name="i_call">'<tt>call</tt>' Instruction</a>
4178</div>
4179
Misha Brukman9d0919f2003-11-08 01:05:38 +00004180<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +00004181
Chris Lattner00950542001-06-06 20:29:01 +00004182<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +00004183<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +00004184 &lt;result&gt; = [tail] call [<a href="#callingconv">cconv</a>] &lt;ty&gt; [&lt;fnty&gt;*] &lt;fnptrval&gt;(&lt;param list&gt;)
Chris Lattner2bff5242005-05-06 05:47:36 +00004185</pre>
4186
Chris Lattner00950542001-06-06 20:29:01 +00004187<h5>Overview:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +00004188
Misha Brukman9d0919f2003-11-08 01:05:38 +00004189<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +00004190
Chris Lattner00950542001-06-06 20:29:01 +00004191<h5>Arguments:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +00004192
Misha Brukman9d0919f2003-11-08 01:05:38 +00004193<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +00004194
Chris Lattner6536cfe2002-05-06 22:08:29 +00004195<ol>
Chris Lattner261efe92003-11-25 01:02:51 +00004196 <li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +00004197 <p>The optional "tail" marker indicates whether the callee function accesses
4198 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattner2bff5242005-05-06 05:47:36 +00004199 function call is eligible for tail call optimization. Note that calls may
4200 be marked "tail" even if they do not occur before a <a
4201 href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner261efe92003-11-25 01:02:51 +00004202 </li>
4203 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +00004204 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +00004205 convention</a> the call should use. If none is specified, the call defaults
4206 to using C calling conventions.
4207 </li>
4208 <li>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +00004209 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
4210 the type of the return value. Functions that return no value are marked
4211 <tt><a href="#t_void">void</a></tt>.</p>
4212 </li>
4213 <li>
4214 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
4215 value being invoked. The argument types must match the types implied by
4216 this signature. This type can be omitted if the function is not varargs
4217 and if the function type does not return a pointer to a function.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +00004218 </li>
4219 <li>
4220 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4221 be invoked. In most cases, this is a direct function invocation, but
4222 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswellfc6b8952005-05-16 16:17:45 +00004223 to function value.</p>
Chris Lattner261efe92003-11-25 01:02:51 +00004224 </li>
4225 <li>
4226 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencera7e302a2005-05-01 22:22:57 +00004227 function signature argument types. All arguments must be of
4228 <a href="#t_firstclass">first class</a> type. If the function signature
4229 indicates the function accepts a variable number of arguments, the extra
4230 arguments can be specified.</p>
Chris Lattner261efe92003-11-25 01:02:51 +00004231 </li>
Chris Lattner6536cfe2002-05-06 22:08:29 +00004232</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +00004233
Chris Lattner00950542001-06-06 20:29:01 +00004234<h5>Semantics:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +00004235
Chris Lattner261efe92003-11-25 01:02:51 +00004236<p>The '<tt>call</tt>' instruction is used to cause control flow to
4237transfer to a specified function, with its incoming arguments bound to
4238the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
4239instruction in the called function, control flow continues with the
4240instruction after the function call, and the return value of the
Chris Lattner772fccf2008-03-21 17:24:17 +00004241function is bound to the result argument. If the callee returns multiple
4242values then the return values of the function are only accessible through
4243the '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +00004244
Chris Lattner00950542001-06-06 20:29:01 +00004245<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +00004246
4247<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +00004248 %retval = call i32 @test(i32 %argc)
Chris Lattner772fccf2008-03-21 17:24:17 +00004249 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4250 %X = tail call i32 @foo() <i>; yields i32</i>
4251 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4252 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +00004253
4254 %struct.A = type { i32, i8 }
Chris Lattner772fccf2008-03-21 17:24:17 +00004255 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
4256 %gr = getresult %struct.A %r, 0 <i>; yields i32</i>
4257 %gr1 = getresult %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner2bff5242005-05-06 05:47:36 +00004258</pre>
4259
Misha Brukman9d0919f2003-11-08 01:05:38 +00004260</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +00004261
Chris Lattnerd9ad5b32003-05-08 04:57:36 +00004262<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +00004263<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +00004264 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +00004265</div>
4266
Misha Brukman9d0919f2003-11-08 01:05:38 +00004267<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +00004268
Chris Lattner8d1a81d2003-10-18 05:51:36 +00004269<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +00004270
4271<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +00004272 &lt;resultval&gt; = va_arg &lt;va_list*&gt; &lt;arglist&gt;, &lt;argty&gt;
Chris Lattnere19d7a72004-09-27 21:51:25 +00004273</pre>
4274
Chris Lattner8d1a81d2003-10-18 05:51:36 +00004275<h5>Overview:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +00004276
Andrew Lenharth8bf607a2005-06-18 18:28:17 +00004277<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattnere19d7a72004-09-27 21:51:25 +00004278the "variable argument" area of a function call. It is used to implement the
4279<tt>va_arg</tt> macro in C.</p>
4280
Chris Lattner8d1a81d2003-10-18 05:51:36 +00004281<h5>Arguments:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +00004282
Andrew Lenharth8bf607a2005-06-18 18:28:17 +00004283<p>This instruction takes a <tt>va_list*</tt> value and the type of
4284the argument. It returns a value of the specified argument type and
Jeff Cohenb627eab2007-04-29 01:07:00 +00004285increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth8bf607a2005-06-18 18:28:17 +00004286actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +00004287
Chris Lattner8d1a81d2003-10-18 05:51:36 +00004288<h5>Semantics:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +00004289
Andrew Lenharth8bf607a2005-06-18 18:28:17 +00004290<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
4291type from the specified <tt>va_list</tt> and causes the
4292<tt>va_list</tt> to point to the next argument. For more information,
4293see the variable argument handling <a href="#int_varargs">Intrinsic
4294Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +00004295
4296<p>It is legal for this instruction to be called in a function which does not
4297take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman9d0919f2003-11-08 01:05:38 +00004298function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +00004299
Andrew Lenharth8bf607a2005-06-18 18:28:17 +00004300<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswellfc6b8952005-05-16 16:17:45 +00004301href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattnere19d7a72004-09-27 21:51:25 +00004302argument.</p>
4303
Chris Lattner8d1a81d2003-10-18 05:51:36 +00004304<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +00004305
4306<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4307
Misha Brukman9d0919f2003-11-08 01:05:38 +00004308</div>
Chris Lattner8ff75902004-01-06 05:31:32 +00004309
Devang Patelc3fc6df2008-03-10 20:49:15 +00004310<!-- _______________________________________________________________________ -->
4311<div class="doc_subsubsection">
4312 <a name="i_getresult">'<tt>getresult</tt>' Instruction</a>
4313</div>
4314
4315<div class="doc_text">
4316
4317<h5>Syntax:</h5>
4318<pre>
Chris Lattner45c5e8b2008-03-21 17:20:51 +00004319 &lt;resultval&gt; = getresult &lt;type&gt; &lt;retval&gt;, &lt;index&gt;
Devang Patelc3fc6df2008-03-10 20:49:15 +00004320</pre>
Chris Lattner45c5e8b2008-03-21 17:20:51 +00004321
Devang Patelc3fc6df2008-03-10 20:49:15 +00004322<h5>Overview:</h5>
4323
4324<p> The '<tt>getresult</tt>' instruction is used to extract individual values
Chris Lattner45c5e8b2008-03-21 17:20:51 +00004325from a '<tt><a href="#i_call">call</a></tt>'
4326or '<tt><a href="#i_invoke">invoke</a></tt>' instruction that returns multiple
4327results.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +00004328
4329<h5>Arguments:</h5>
4330
Chris Lattner45c5e8b2008-03-21 17:20:51 +00004331<p>The '<tt>getresult</tt>' instruction takes a call or invoke value as its
Chris Lattner1c406d72008-04-23 04:06:52 +00004332first argument, or an undef value. The value must have <a
4333href="#t_struct">structure type</a>. The second argument is a constant
4334unsigned index value which must be in range for the number of values returned
4335by the call.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +00004336
4337<h5>Semantics:</h5>
4338
Chris Lattner45c5e8b2008-03-21 17:20:51 +00004339<p>The '<tt>getresult</tt>' instruction extracts the element identified by
4340'<tt>index</tt>' from the aggregate value.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +00004341
4342<h5>Example:</h5>
4343
4344<pre>
4345 %struct.A = type { i32, i8 }
4346
4347 %r = call %struct.A @foo()
Chris Lattner45c5e8b2008-03-21 17:20:51 +00004348 %gr = getresult %struct.A %r, 0 <i>; yields i32:%gr</i>
4349 %gr1 = getresult %struct.A %r, 1 <i>; yields i8:%gr1</i>
Devang Patelc3fc6df2008-03-10 20:49:15 +00004350 add i32 %gr, 42
4351 add i8 %gr1, 41
4352</pre>
4353
4354</div>
4355
Chris Lattnerd9ad5b32003-05-08 04:57:36 +00004356<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +00004357<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4358<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +00004359
Misha Brukman9d0919f2003-11-08 01:05:38 +00004360<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +00004361
4362<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer409e28f2007-04-01 08:04:23 +00004363well known names and semantics and are required to follow certain restrictions.
4364Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohenb627eab2007-04-29 01:07:00 +00004365language that does not require changing all of the transformations in LLVM when
Gabor Greif04367bf2007-07-06 22:07:22 +00004366adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +00004367
John Criswellfc6b8952005-05-16 16:17:45 +00004368<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohenb627eab2007-04-29 01:07:00 +00004369prefix is reserved in LLVM for intrinsic names; thus, function names may not
4370begin with this prefix. Intrinsic functions must always be external functions:
4371you cannot define the body of intrinsic functions. Intrinsic functions may
4372only be used in call or invoke instructions: it is illegal to take the address
4373of an intrinsic function. Additionally, because intrinsic functions are part
4374of the LLVM language, it is required if any are added that they be documented
4375here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +00004376
Chandler Carruth69940402007-08-04 01:51:18 +00004377<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
4378a family of functions that perform the same operation but on different data
4379types. Because LLVM can represent over 8 million different integer types,
4380overloading is used commonly to allow an intrinsic function to operate on any
4381integer type. One or more of the argument types or the result type can be
4382overloaded to accept any integer type. Argument types may also be defined as
4383exactly matching a previous argument's type or the result type. This allows an
4384intrinsic function which accepts multiple arguments, but needs all of them to
4385be of the same type, to only be overloaded with respect to a single argument or
4386the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +00004387
Chandler Carruth69940402007-08-04 01:51:18 +00004388<p>Overloaded intrinsics will have the names of its overloaded argument types
4389encoded into its function name, each preceded by a period. Only those types
4390which are overloaded result in a name suffix. Arguments whose type is matched
4391against another type do not. For example, the <tt>llvm.ctpop</tt> function can
4392take an integer of any width and returns an integer of exactly the same integer
4393width. This leads to a family of functions such as
4394<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
4395Only one type, the return type, is overloaded, and only one type suffix is
4396required. Because the argument's type is matched against the return type, it
4397does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +00004398
4399<p>To learn how to add an intrinsic function, please see the
4400<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner33aec9e2004-02-12 17:01:32 +00004401</p>
4402
Misha Brukman9d0919f2003-11-08 01:05:38 +00004403</div>
Chris Lattner8ff75902004-01-06 05:31:32 +00004404
Chris Lattnerd9ad5b32003-05-08 04:57:36 +00004405<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +00004406<div class="doc_subsection">
4407 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
4408</div>
4409
Misha Brukman9d0919f2003-11-08 01:05:38 +00004410<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +00004411
Misha Brukman9d0919f2003-11-08 01:05:38 +00004412<p>Variable argument support is defined in LLVM with the <a
Chris Lattnerfb6977d2006-01-13 23:26:01 +00004413 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner261efe92003-11-25 01:02:51 +00004414intrinsic functions. These functions are related to the similarly
4415named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +00004416
Chris Lattner261efe92003-11-25 01:02:51 +00004417<p>All of these functions operate on arguments that use a
4418target-specific value type "<tt>va_list</tt>". The LLVM assembly
4419language reference manual does not define what this type is, so all
Jeff Cohenb627eab2007-04-29 01:07:00 +00004420transformations should be prepared to handle these functions regardless of
4421the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +00004422
Chris Lattner374ab302006-05-15 17:26:46 +00004423<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Chris Lattner261efe92003-11-25 01:02:51 +00004424instruction and the variable argument handling intrinsic functions are
4425used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +00004426
Bill Wendling2f7a8b02007-05-29 09:04:49 +00004427<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +00004428<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +00004429define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +00004430 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +00004431 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +00004432 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +00004433 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +00004434
4435 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +00004436 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +00004437
4438 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +00004439 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +00004440 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +00004441 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +00004442 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +00004443
4444 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +00004445 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +00004446 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +00004447}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +00004448
4449declare void @llvm.va_start(i8*)
4450declare void @llvm.va_copy(i8*, i8*)
4451declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +00004452</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +00004453</div>
Chris Lattner8ff75902004-01-06 05:31:32 +00004454
Bill Wendling2f7a8b02007-05-29 09:04:49 +00004455</div>
4456
Chris Lattnerd9ad5b32003-05-08 04:57:36 +00004457<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +00004458<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +00004459 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +00004460</div>
4461
4462
Misha Brukman9d0919f2003-11-08 01:05:38 +00004463<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +00004464<h5>Syntax:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +00004465<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +00004466<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +00004467<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
4468<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
4469href="#i_va_arg">va_arg</a></tt>.</p>
4470
4471<h5>Arguments:</h5>
4472
4473<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
4474
Chris Lattnerd9ad5b32003-05-08 04:57:36 +00004475<h5>Semantics:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +00004476
4477<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
4478macro available in C. In a target-dependent way, it initializes the
Jeff Cohenb627eab2007-04-29 01:07:00 +00004479<tt>va_list</tt> element to which the argument points, so that the next call to
Andrew Lenharth8bf607a2005-06-18 18:28:17 +00004480<tt>va_arg</tt> will produce the first variable argument passed to the function.
4481Unlike the C <tt>va_start</tt> macro, this intrinsic does not need to know the
Jeff Cohenb627eab2007-04-29 01:07:00 +00004482last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +00004483
Misha Brukman9d0919f2003-11-08 01:05:38 +00004484</div>
Chris Lattner8ff75902004-01-06 05:31:32 +00004485
Chris Lattnerd9ad5b32003-05-08 04:57:36 +00004486<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +00004487<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +00004488 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +00004489</div>
4490
Misha Brukman9d0919f2003-11-08 01:05:38 +00004491<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +00004492<h5>Syntax:</h5>
Anton Korobeynikovec43a062007-03-22 00:02:17 +00004493<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +00004494<h5>Overview:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +00004495
Jeff Cohenb627eab2007-04-29 01:07:00 +00004496<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencera3e435f2007-04-04 02:42:35 +00004497which has been initialized previously with <tt><a href="#int_va_start">llvm.va_start</a></tt>
Chris Lattner261efe92003-11-25 01:02:51 +00004498or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +00004499
Chris Lattnerd9ad5b32003-05-08 04:57:36 +00004500<h5>Arguments:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +00004501
Jeff Cohenb627eab2007-04-29 01:07:00 +00004502<p>The argument is a pointer to a <tt>va_list</tt> to destroy.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +00004503
Chris Lattnerd9ad5b32003-05-08 04:57:36 +00004504<h5>Semantics:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +00004505
Misha Brukman9d0919f2003-11-08 01:05:38 +00004506<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Jeff Cohenb627eab2007-04-29 01:07:00 +00004507macro available in C. In a target-dependent way, it destroys the
4508<tt>va_list</tt> element to which the argument points. Calls to <a
4509href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
4510<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
4511<tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +00004512
Misha Brukman9d0919f2003-11-08 01:05:38 +00004513</div>
Chris Lattner8ff75902004-01-06 05:31:32 +00004514
Chris Lattnerd9ad5b32003-05-08 04:57:36 +00004515<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +00004516<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +00004517 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +00004518</div>
4519
Misha Brukman9d0919f2003-11-08 01:05:38 +00004520<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +00004521
Chris Lattnerd9ad5b32003-05-08 04:57:36 +00004522<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +00004523
4524<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +00004525 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +00004526</pre>
4527
Chris Lattnerd9ad5b32003-05-08 04:57:36 +00004528<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +00004529
Jeff Cohenb627eab2007-04-29 01:07:00 +00004530<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
4531from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +00004532
Chris Lattnerd9ad5b32003-05-08 04:57:36 +00004533<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +00004534
Andrew Lenharth8bf607a2005-06-18 18:28:17 +00004535<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Andrew Lenharthd0a4c622005-06-22 20:38:11 +00004536The second argument is a pointer to a <tt>va_list</tt> element to copy from.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +00004537
Chris Lattnerd7923912004-05-23 21:06:01 +00004538
Chris Lattnerd9ad5b32003-05-08 04:57:36 +00004539<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +00004540
Jeff Cohenb627eab2007-04-29 01:07:00 +00004541<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
4542macro available in C. In a target-dependent way, it copies the source
4543<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
4544intrinsic is necessary because the <tt><a href="#int_va_start">
4545llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
4546example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +00004547
Misha Brukman9d0919f2003-11-08 01:05:38 +00004548</div>
Chris Lattner8ff75902004-01-06 05:31:32 +00004549
Chris Lattner33aec9e2004-02-12 17:01:32 +00004550<!-- ======================================================================= -->
4551<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +00004552 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
4553</div>
4554
4555<div class="doc_text">
4556
4557<p>
4558LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +00004559Collection</a> (GC) requires the implementation and generation of these
4560intrinsics.
Reid Spencera3e435f2007-04-04 02:42:35 +00004561These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattnerd7923912004-05-23 21:06:01 +00004562stack</a>, as well as garbage collector implementations that require <a
Reid Spencera3e435f2007-04-04 02:42:35 +00004563href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattnerd7923912004-05-23 21:06:01 +00004564Front-ends for type-safe garbage collected languages should generate these
4565intrinsics to make use of the LLVM garbage collectors. For more details, see <a
4566href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
4567</p>
Christopher Lamb303dae92007-12-17 01:00:21 +00004568
4569<p>The garbage collection intrinsics only operate on objects in the generic
4570 address space (address space zero).</p>
4571
Chris Lattnerd7923912004-05-23 21:06:01 +00004572</div>
4573
4574<!-- _______________________________________________________________________ -->
4575<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +00004576 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +00004577</div>
4578
4579<div class="doc_text">
4580
4581<h5>Syntax:</h5>
4582
4583<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +00004584 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +00004585</pre>
4586
4587<h5>Overview:</h5>
4588
John Criswell9e2485c2004-12-10 15:51:16 +00004589<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Chris Lattnerd7923912004-05-23 21:06:01 +00004590the code generator, and allows some metadata to be associated with it.</p>
4591
4592<h5>Arguments:</h5>
4593
4594<p>The first argument specifies the address of a stack object that contains the
4595root pointer. The second pointer (which must be either a constant or a global
4596value address) contains the meta-data to be associated with the root.</p>
4597
4598<h5>Semantics:</h5>
4599
Chris Lattner05d67092008-04-24 05:59:56 +00004600<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Chris Lattnerd7923912004-05-23 21:06:01 +00004601location. At compile-time, the code generator generates information to allow
Gordon Henriksene1433f22007-12-25 02:31:26 +00004602the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
4603intrinsic may only be used in a function which <a href="#gc">specifies a GC
4604algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +00004605
4606</div>
4607
4608
4609<!-- _______________________________________________________________________ -->
4610<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +00004611 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +00004612</div>
4613
4614<div class="doc_text">
4615
4616<h5>Syntax:</h5>
4617
4618<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +00004619 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +00004620</pre>
4621
4622<h5>Overview:</h5>
4623
4624<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4625locations, allowing garbage collector implementations that require read
4626barriers.</p>
4627
4628<h5>Arguments:</h5>
4629
Chris Lattner80626e92006-03-14 20:02:51 +00004630<p>The second argument is the address to read from, which should be an address
4631allocated from the garbage collector. The first object is a pointer to the
4632start of the referenced object, if needed by the language runtime (otherwise
4633null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +00004634
4635<h5>Semantics:</h5>
4636
4637<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4638instruction, but may be replaced with substantially more complex code by the
Gordon Henriksene1433f22007-12-25 02:31:26 +00004639garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
4640may only be used in a function which <a href="#gc">specifies a GC
4641algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +00004642
4643</div>
4644
4645
4646<!-- _______________________________________________________________________ -->
4647<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +00004648 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +00004649</div>
4650
4651<div class="doc_text">
4652
4653<h5>Syntax:</h5>
4654
4655<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +00004656 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +00004657</pre>
4658
4659<h5>Overview:</h5>
4660
4661<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4662locations, allowing garbage collector implementations that require write
4663barriers (such as generational or reference counting collectors).</p>
4664
4665<h5>Arguments:</h5>
4666
Chris Lattner80626e92006-03-14 20:02:51 +00004667<p>The first argument is the reference to store, the second is the start of the
4668object to store it to, and the third is the address of the field of Obj to
4669store to. If the runtime does not require a pointer to the object, Obj may be
4670null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +00004671
4672<h5>Semantics:</h5>
4673
4674<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4675instruction, but may be replaced with substantially more complex code by the
Gordon Henriksene1433f22007-12-25 02:31:26 +00004676garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
4677may only be used in a function which <a href="#gc">specifies a GC
4678algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +00004679
4680</div>
4681
4682
4683
4684<!-- ======================================================================= -->
4685<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +00004686 <a name="int_codegen">Code Generator Intrinsics</a>
4687</div>
4688
4689<div class="doc_text">
4690<p>
4691These intrinsics are provided by LLVM to expose special features that may only
4692be implemented with code generator support.
4693</p>
4694
4695</div>
4696
4697<!-- _______________________________________________________________________ -->
4698<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +00004699 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +00004700</div>
4701
4702<div class="doc_text">
4703
4704<h5>Syntax:</h5>
4705<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +00004706 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +00004707</pre>
4708
4709<h5>Overview:</h5>
4710
4711<p>
Chris Lattner32b5d712006-10-15 20:05:59 +00004712The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4713target-specific value indicating the return address of the current function
4714or one of its callers.
Chris Lattner10610642004-02-14 04:08:35 +00004715</p>
4716
4717<h5>Arguments:</h5>
4718
4719<p>
4720The argument to this intrinsic indicates which function to return the address
4721for. Zero indicates the calling function, one indicates its caller, etc. The
4722argument is <b>required</b> to be a constant integer value.
4723</p>
4724
4725<h5>Semantics:</h5>
4726
4727<p>
4728The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4729the return address of the specified call frame, or zero if it cannot be
4730identified. The value returned by this intrinsic is likely to be incorrect or 0
4731for arguments other than zero, so it should only be used for debugging purposes.
4732</p>
4733
4734<p>
4735Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +00004736aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +00004737source-language caller.
4738</p>
4739</div>
4740
4741
4742<!-- _______________________________________________________________________ -->
4743<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +00004744 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +00004745</div>
4746
4747<div class="doc_text">
4748
4749<h5>Syntax:</h5>
4750<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +00004751 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +00004752</pre>
4753
4754<h5>Overview:</h5>
4755
4756<p>
Chris Lattner32b5d712006-10-15 20:05:59 +00004757The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
4758target-specific frame pointer value for the specified stack frame.
Chris Lattner10610642004-02-14 04:08:35 +00004759</p>
4760
4761<h5>Arguments:</h5>
4762
4763<p>
4764The argument to this intrinsic indicates which function to return the frame
4765pointer for. Zero indicates the calling function, one indicates its caller,
4766etc. The argument is <b>required</b> to be a constant integer value.
4767</p>
4768
4769<h5>Semantics:</h5>
4770
4771<p>
4772The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
4773the frame address of the specified call frame, or zero if it cannot be
4774identified. The value returned by this intrinsic is likely to be incorrect or 0
4775for arguments other than zero, so it should only be used for debugging purposes.
4776</p>
4777
4778<p>
4779Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +00004780aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +00004781source-language caller.
4782</p>
4783</div>
4784
Chris Lattner9a9d7ac2005-02-28 19:24:19 +00004785<!-- _______________________________________________________________________ -->
4786<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +00004787 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +00004788</div>
4789
4790<div class="doc_text">
4791
4792<h5>Syntax:</h5>
4793<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +00004794 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +00004795</pre>
4796
4797<h5>Overview:</h5>
4798
4799<p>
4800The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencera3e435f2007-04-04 02:42:35 +00004801the function stack, for use with <a href="#int_stackrestore">
Chris Lattner57e1f392006-01-13 02:03:13 +00004802<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
4803features like scoped automatic variable sized arrays in C99.
4804</p>
4805
4806<h5>Semantics:</h5>
4807
4808<p>
4809This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencera3e435f2007-04-04 02:42:35 +00004810href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner57e1f392006-01-13 02:03:13 +00004811<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
4812<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
4813state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
4814practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
4815that were allocated after the <tt>llvm.stacksave</tt> was executed.
4816</p>
4817
4818</div>
4819
4820<!-- _______________________________________________________________________ -->
4821<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +00004822 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +00004823</div>
4824
4825<div class="doc_text">
4826
4827<h5>Syntax:</h5>
4828<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +00004829 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +00004830</pre>
4831
4832<h5>Overview:</h5>
4833
4834<p>
4835The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
4836the function stack to the state it was in when the corresponding <a
Reid Spencera3e435f2007-04-04 02:42:35 +00004837href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner57e1f392006-01-13 02:03:13 +00004838useful for implementing language features like scoped automatic variable sized
4839arrays in C99.
4840</p>
4841
4842<h5>Semantics:</h5>
4843
4844<p>
Reid Spencera3e435f2007-04-04 02:42:35 +00004845See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner57e1f392006-01-13 02:03:13 +00004846</p>
4847
4848</div>
4849
4850
4851<!-- _______________________________________________________________________ -->
4852<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +00004853 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +00004854</div>
4855
4856<div class="doc_text">
4857
4858<h5>Syntax:</h5>
4859<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +00004860 declare void @llvm.prefetch(i8* &lt;address&gt;, i32 &lt;rw&gt;, i32 &lt;locality&gt;)
Chris Lattner9a9d7ac2005-02-28 19:24:19 +00004861</pre>
4862
4863<h5>Overview:</h5>
4864
4865
4866<p>
4867The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswellfc6b8952005-05-16 16:17:45 +00004868a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
4869no
4870effect on the behavior of the program but can change its performance
Chris Lattner2a615362005-02-28 19:47:14 +00004871characteristics.
Chris Lattner9a9d7ac2005-02-28 19:24:19 +00004872</p>
4873
4874<h5>Arguments:</h5>
4875
4876<p>
4877<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
4878determining if the fetch should be for a read (0) or write (1), and
4879<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattneraeffb4a2005-03-07 20:31:38 +00004880locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattner9a9d7ac2005-02-28 19:24:19 +00004881<tt>locality</tt> arguments must be constant integers.
4882</p>
4883
4884<h5>Semantics:</h5>
4885
4886<p>
4887This intrinsic does not modify the behavior of the program. In particular,
4888prefetches cannot trap and do not produce a value. On targets that support this
4889intrinsic, the prefetch can provide hints to the processor cache for better
4890performance.
4891</p>
4892
4893</div>
4894
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +00004895<!-- _______________________________________________________________________ -->
4896<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +00004897 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +00004898</div>
4899
4900<div class="doc_text">
4901
4902<h5>Syntax:</h5>
4903<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +00004904 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +00004905</pre>
4906
4907<h5>Overview:</h5>
4908
4909
4910<p>
John Criswellfc6b8952005-05-16 16:17:45 +00004911The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattnerd3eda892008-08-05 18:29:16 +00004912(PC) in a region of
4913code to simulators and other tools. The method is target specific, but it is
4914expected that the marker will use exported symbols to transmit the PC of the
4915marker.
4916The marker makes no guarantees that it will remain with any specific instruction
4917after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb3e7afd2006-03-24 07:16:10 +00004918optimizations. The intended use is to be inserted after optimizations to allow
John Criswellfc6b8952005-05-16 16:17:45 +00004919correlations of simulation runs.
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +00004920</p>
4921
4922<h5>Arguments:</h5>
4923
4924<p>
4925<tt>id</tt> is a numerical id identifying the marker.
4926</p>
4927
4928<h5>Semantics:</h5>
4929
4930<p>
4931This intrinsic does not modify the behavior of the program. Backends that do not
4932support this intrinisic may ignore it.
4933</p>
4934
4935</div>
4936
Andrew Lenharth51b8d542005-11-11 16:47:30 +00004937<!-- _______________________________________________________________________ -->
4938<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +00004939 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +00004940</div>
4941
4942<div class="doc_text">
4943
4944<h5>Syntax:</h5>
4945<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +00004946 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +00004947</pre>
4948
4949<h5>Overview:</h5>
4950
4951
4952<p>
4953The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
4954counter register (or similar low latency, high accuracy clocks) on those targets
4955that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
4956As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
4957should only be used for small timings.
4958</p>
4959
4960<h5>Semantics:</h5>
4961
4962<p>
4963When directly supported, reading the cycle counter should not modify any memory.
4964Implementations are allowed to either return a application specific value or a
4965system wide value. On backends without support, this is lowered to a constant 0.
4966</p>
4967
4968</div>
4969
Chris Lattner10610642004-02-14 04:08:35 +00004970<!-- ======================================================================= -->
4971<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +00004972 <a name="int_libc">Standard C Library Intrinsics</a>
4973</div>
4974
4975<div class="doc_text">
4976<p>
Chris Lattner10610642004-02-14 04:08:35 +00004977LLVM provides intrinsics for a few important standard C library functions.
4978These intrinsics allow source-language front-ends to pass information about the
4979alignment of the pointer arguments to the code generator, providing opportunity
4980for more efficient code generation.
Chris Lattner33aec9e2004-02-12 17:01:32 +00004981</p>
4982
4983</div>
4984
4985<!-- _______________________________________________________________________ -->
4986<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +00004987 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +00004988</div>
4989
4990<div class="doc_text">
4991
4992<h5>Syntax:</h5>
4993<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +00004994 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +00004995 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +00004996 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +00004997 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +00004998</pre>
4999
5000<h5>Overview:</h5>
5001
5002<p>
Chris Lattner5b310c32006-03-03 00:07:20 +00005003The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +00005004location to the destination location.
5005</p>
5006
5007<p>
Chris Lattner5b310c32006-03-03 00:07:20 +00005008Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5009intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner33aec9e2004-02-12 17:01:32 +00005010</p>
5011
5012<h5>Arguments:</h5>
5013
5014<p>
5015The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +00005016the source. The third argument is an integer argument
Chris Lattner33aec9e2004-02-12 17:01:32 +00005017specifying the number of bytes to copy, and the fourth argument is the alignment
5018of the source and destination locations.
5019</p>
5020
Chris Lattner3301ced2004-02-12 21:18:15 +00005021<p>
5022If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattnerf0afc2c2006-03-04 00:02:10 +00005023the caller guarantees that both the source and destination pointers are aligned
5024to that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +00005025</p>
5026
Chris Lattner33aec9e2004-02-12 17:01:32 +00005027<h5>Semantics:</h5>
5028
5029<p>
Chris Lattner5b310c32006-03-03 00:07:20 +00005030The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +00005031location to the destination location, which are not allowed to overlap. It
5032copies "len" bytes of memory over. If the argument is known to be aligned to
5033some boundary, this can be specified as the fourth argument, otherwise it should
5034be set to 0 or 1.
5035</p>
5036</div>
5037
5038
Chris Lattner0eb51b42004-02-12 18:10:10 +00005039<!-- _______________________________________________________________________ -->
5040<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +00005041 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +00005042</div>
5043
5044<div class="doc_text">
5045
5046<h5>Syntax:</h5>
5047<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +00005048 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +00005049 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +00005050 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +00005051 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +00005052</pre>
5053
5054<h5>Overview:</h5>
5055
5056<p>
Chris Lattner5b310c32006-03-03 00:07:20 +00005057The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
5058location to the destination location. It is similar to the
Chris Lattner4b2cbcf2008-01-06 19:51:52 +00005059'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattner0eb51b42004-02-12 18:10:10 +00005060</p>
5061
5062<p>
Chris Lattner5b310c32006-03-03 00:07:20 +00005063Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5064intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner0eb51b42004-02-12 18:10:10 +00005065</p>
5066
5067<h5>Arguments:</h5>
5068
5069<p>
5070The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +00005071the source. The third argument is an integer argument
Chris Lattner0eb51b42004-02-12 18:10:10 +00005072specifying the number of bytes to copy, and the fourth argument is the alignment
5073of the source and destination locations.
5074</p>
5075
Chris Lattner3301ced2004-02-12 21:18:15 +00005076<p>
5077If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattnerf0afc2c2006-03-04 00:02:10 +00005078the caller guarantees that the source and destination pointers are aligned to
5079that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +00005080</p>
5081
Chris Lattner0eb51b42004-02-12 18:10:10 +00005082<h5>Semantics:</h5>
5083
5084<p>
Chris Lattner5b310c32006-03-03 00:07:20 +00005085The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner0eb51b42004-02-12 18:10:10 +00005086location to the destination location, which may overlap. It
5087copies "len" bytes of memory over. If the argument is known to be aligned to
5088some boundary, this can be specified as the fourth argument, otherwise it should
5089be set to 0 or 1.
5090</p>
5091</div>
5092
Chris Lattner8ff75902004-01-06 05:31:32 +00005093
Chris Lattner10610642004-02-14 04:08:35 +00005094<!-- _______________________________________________________________________ -->
5095<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +00005096 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +00005097</div>
5098
5099<div class="doc_text">
5100
5101<h5>Syntax:</h5>
5102<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +00005103 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +00005104 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +00005105 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +00005106 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +00005107</pre>
5108
5109<h5>Overview:</h5>
5110
5111<p>
Chris Lattner5b310c32006-03-03 00:07:20 +00005112The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner10610642004-02-14 04:08:35 +00005113byte value.
5114</p>
5115
5116<p>
5117Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
5118does not return a value, and takes an extra alignment argument.
5119</p>
5120
5121<h5>Arguments:</h5>
5122
5123<p>
5124The first argument is a pointer to the destination to fill, the second is the
Chris Lattner5b310c32006-03-03 00:07:20 +00005125byte value to fill it with, the third argument is an integer
Chris Lattner10610642004-02-14 04:08:35 +00005126argument specifying the number of bytes to fill, and the fourth argument is the
5127known alignment of destination location.
5128</p>
5129
5130<p>
5131If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattnerf0afc2c2006-03-04 00:02:10 +00005132the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner10610642004-02-14 04:08:35 +00005133</p>
5134
5135<h5>Semantics:</h5>
5136
5137<p>
Chris Lattner5b310c32006-03-03 00:07:20 +00005138The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
5139the
Chris Lattner10610642004-02-14 04:08:35 +00005140destination location. If the argument is known to be aligned to some boundary,
5141this can be specified as the fourth argument, otherwise it should be set to 0 or
51421.
5143</p>
5144</div>
5145
5146
Chris Lattner32006282004-06-11 02:28:03 +00005147<!-- _______________________________________________________________________ -->
5148<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +00005149 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +00005150</div>
5151
5152<div class="doc_text">
5153
5154<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +00005155<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
Dan Gohman91c284c2007-10-15 20:30:11 +00005156floating point or vector of floating point type. Not all targets support all
5157types however.
Chris Lattnera4d74142005-07-21 01:29:16 +00005158<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +00005159 declare float @llvm.sqrt.f32(float %Val)
5160 declare double @llvm.sqrt.f64(double %Val)
5161 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5162 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5163 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +00005164</pre>
5165
5166<h5>Overview:</h5>
5167
5168<p>
Reid Spencer0b118202006-01-16 21:12:35 +00005169The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohman91c284c2007-10-15 20:30:11 +00005170returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattnera4d74142005-07-21 01:29:16 +00005171<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner103e2d72008-01-29 07:00:44 +00005172negative numbers other than -0.0 (which allows for better optimization, because
5173there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
5174defined to return -0.0 like IEEE sqrt.
Chris Lattnera4d74142005-07-21 01:29:16 +00005175</p>
5176
5177<h5>Arguments:</h5>
5178
5179<p>
5180The argument and return value are floating point numbers of the same type.
5181</p>
5182
5183<h5>Semantics:</h5>
5184
5185<p>
Dan Gohmand6257fe2007-07-16 14:37:41 +00005186This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattnera4d74142005-07-21 01:29:16 +00005187floating point number.
5188</p>
5189</div>
5190
Chris Lattnerf4d252d2006-09-08 06:34:02 +00005191<!-- _______________________________________________________________________ -->
5192<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +00005193 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +00005194</div>
5195
5196<div class="doc_text">
5197
5198<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +00005199<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
Dan Gohman91c284c2007-10-15 20:30:11 +00005200floating point or vector of floating point type. Not all targets support all
5201types however.
Chris Lattnerf4d252d2006-09-08 06:34:02 +00005202<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +00005203 declare float @llvm.powi.f32(float %Val, i32 %power)
5204 declare double @llvm.powi.f64(double %Val, i32 %power)
5205 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5206 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5207 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +00005208</pre>
5209
5210<h5>Overview:</h5>
5211
5212<p>
5213The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5214specified (positive or negative) power. The order of evaluation of
Dan Gohman91c284c2007-10-15 20:30:11 +00005215multiplications is not defined. When a vector of floating point type is
5216used, the second argument remains a scalar integer value.
Chris Lattnerf4d252d2006-09-08 06:34:02 +00005217</p>
5218
5219<h5>Arguments:</h5>
5220
5221<p>
5222The second argument is an integer power, and the first is a value to raise to
5223that power.
5224</p>
5225
5226<h5>Semantics:</h5>
5227
5228<p>
5229This function returns the first value raised to the second power with an
5230unspecified sequence of rounding operations.</p>
5231</div>
5232
Dan Gohman91c284c2007-10-15 20:30:11 +00005233<!-- _______________________________________________________________________ -->
5234<div class="doc_subsubsection">
5235 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5236</div>
5237
5238<div class="doc_text">
5239
5240<h5>Syntax:</h5>
5241<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5242floating point or vector of floating point type. Not all targets support all
5243types however.
5244<pre>
5245 declare float @llvm.sin.f32(float %Val)
5246 declare double @llvm.sin.f64(double %Val)
5247 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5248 declare fp128 @llvm.sin.f128(fp128 %Val)
5249 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5250</pre>
5251
5252<h5>Overview:</h5>
5253
5254<p>
5255The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
5256</p>
5257
5258<h5>Arguments:</h5>
5259
5260<p>
5261The argument and return value are floating point numbers of the same type.
5262</p>
5263
5264<h5>Semantics:</h5>
5265
5266<p>
5267This function returns the sine of the specified operand, returning the
5268same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +00005269conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +00005270</div>
5271
5272<!-- _______________________________________________________________________ -->
5273<div class="doc_subsubsection">
5274 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5275</div>
5276
5277<div class="doc_text">
5278
5279<h5>Syntax:</h5>
5280<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5281floating point or vector of floating point type. Not all targets support all
5282types however.
5283<pre>
5284 declare float @llvm.cos.f32(float %Val)
5285 declare double @llvm.cos.f64(double %Val)
5286 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5287 declare fp128 @llvm.cos.f128(fp128 %Val)
5288 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5289</pre>
5290
5291<h5>Overview:</h5>
5292
5293<p>
5294The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
5295</p>
5296
5297<h5>Arguments:</h5>
5298
5299<p>
5300The argument and return value are floating point numbers of the same type.
5301</p>
5302
5303<h5>Semantics:</h5>
5304
5305<p>
5306This function returns the cosine of the specified operand, returning the
5307same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +00005308conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +00005309</div>
5310
5311<!-- _______________________________________________________________________ -->
5312<div class="doc_subsubsection">
5313 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5314</div>
5315
5316<div class="doc_text">
5317
5318<h5>Syntax:</h5>
5319<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5320floating point or vector of floating point type. Not all targets support all
5321types however.
5322<pre>
5323 declare float @llvm.pow.f32(float %Val, float %Power)
5324 declare double @llvm.pow.f64(double %Val, double %Power)
5325 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5326 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5327 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5328</pre>
5329
5330<h5>Overview:</h5>
5331
5332<p>
5333The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5334specified (positive or negative) power.
5335</p>
5336
5337<h5>Arguments:</h5>
5338
5339<p>
5340The second argument is a floating point power, and the first is a value to
5341raise to that power.
5342</p>
5343
5344<h5>Semantics:</h5>
5345
5346<p>
5347This function returns the first value raised to the second power,
5348returning the
5349same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +00005350conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +00005351</div>
5352
Chris Lattnerf4d252d2006-09-08 06:34:02 +00005353
Andrew Lenharthec370fd2005-05-03 18:01:48 +00005354<!-- ======================================================================= -->
5355<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +00005356 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +00005357</div>
5358
5359<div class="doc_text">
5360<p>
Nate Begeman7e36c472006-01-13 23:26:38 +00005361LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharthec370fd2005-05-03 18:01:48 +00005362These allow efficient code generation for some algorithms.
5363</p>
5364
5365</div>
5366
5367<!-- _______________________________________________________________________ -->
5368<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +00005369 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +00005370</div>
5371
5372<div class="doc_text">
5373
5374<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +00005375<p>This is an overloaded intrinsic function. You can use bswap on any integer
Chandler Carruth69940402007-08-04 01:51:18 +00005376type that is an even number of bytes (i.e. BitWidth % 16 == 0).
Nate Begeman7e36c472006-01-13 23:26:38 +00005377<pre>
Chandler Carruth69940402007-08-04 01:51:18 +00005378 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5379 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5380 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +00005381</pre>
5382
5383<h5>Overview:</h5>
5384
5385<p>
Reid Spencer338ea092007-04-02 02:25:19 +00005386The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer409e28f2007-04-01 08:04:23 +00005387values with an even number of bytes (positive multiple of 16 bits). These are
5388useful for performing operations on data that is not in the target's native
5389byte order.
Nate Begeman7e36c472006-01-13 23:26:38 +00005390</p>
5391
5392<h5>Semantics:</h5>
5393
5394<p>
Chandler Carruth69940402007-08-04 01:51:18 +00005395The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerca86e162006-12-31 07:07:53 +00005396and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
5397intrinsic returns an i32 value that has the four bytes of the input i32
5398swapped, so that if the input bytes are numbered 0, 1, 2, 3 then the returned
Chandler Carruth69940402007-08-04 01:51:18 +00005399i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
5400<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer409e28f2007-04-01 08:04:23 +00005401additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman7e36c472006-01-13 23:26:38 +00005402</p>
5403
5404</div>
5405
5406<!-- _______________________________________________________________________ -->
5407<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +00005408 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +00005409</div>
5410
5411<div class="doc_text">
5412
5413<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +00005414<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
5415width. Not all targets support all bit widths however.
Andrew Lenharthec370fd2005-05-03 18:01:48 +00005416<pre>
Chandler Carruth69940402007-08-04 01:51:18 +00005417 declare i8 @llvm.ctpop.i8 (i8 &lt;src&gt;)
5418 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +00005419 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +00005420 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5421 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +00005422</pre>
5423
5424<h5>Overview:</h5>
5425
5426<p>
Chris Lattnerec6cb612006-01-16 22:38:59 +00005427The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
5428value.
Andrew Lenharthec370fd2005-05-03 18:01:48 +00005429</p>
5430
5431<h5>Arguments:</h5>
5432
5433<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +00005434The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +00005435integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +00005436</p>
5437
5438<h5>Semantics:</h5>
5439
5440<p>
5441The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
5442</p>
5443</div>
5444
5445<!-- _______________________________________________________________________ -->
5446<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +00005447 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +00005448</div>
5449
5450<div class="doc_text">
5451
5452<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +00005453<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
5454integer bit width. Not all targets support all bit widths however.
Andrew Lenharthec370fd2005-05-03 18:01:48 +00005455<pre>
Chandler Carruth69940402007-08-04 01:51:18 +00005456 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5457 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +00005458 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +00005459 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5460 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +00005461</pre>
5462
5463<h5>Overview:</h5>
5464
5465<p>
Reid Spencer0b118202006-01-16 21:12:35 +00005466The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5467leading zeros in a variable.
Andrew Lenharthec370fd2005-05-03 18:01:48 +00005468</p>
5469
5470<h5>Arguments:</h5>
5471
5472<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +00005473The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +00005474integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +00005475</p>
5476
5477<h5>Semantics:</h5>
5478
5479<p>
Chris Lattnereff29ab2005-05-15 19:39:26 +00005480The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
5481in a variable. If the src == 0 then the result is the size in bits of the type
Reid Spencerca86e162006-12-31 07:07:53 +00005482of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharthec370fd2005-05-03 18:01:48 +00005483</p>
5484</div>
Chris Lattner32006282004-06-11 02:28:03 +00005485
5486
Chris Lattnereff29ab2005-05-15 19:39:26 +00005487
5488<!-- _______________________________________________________________________ -->
5489<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +00005490 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +00005491</div>
5492
5493<div class="doc_text">
5494
5495<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +00005496<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
5497integer bit width. Not all targets support all bit widths however.
Chris Lattnereff29ab2005-05-15 19:39:26 +00005498<pre>
Chandler Carruth69940402007-08-04 01:51:18 +00005499 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5500 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +00005501 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +00005502 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5503 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +00005504</pre>
5505
5506<h5>Overview:</h5>
5507
5508<p>
Reid Spencer0b118202006-01-16 21:12:35 +00005509The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5510trailing zeros.
Chris Lattnereff29ab2005-05-15 19:39:26 +00005511</p>
5512
5513<h5>Arguments:</h5>
5514
5515<p>
5516The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +00005517integer type. The return type must match the argument type.
Chris Lattnereff29ab2005-05-15 19:39:26 +00005518</p>
5519
5520<h5>Semantics:</h5>
5521
5522<p>
5523The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
5524in a variable. If the src == 0 then the result is the size in bits of the type
5525of src. For example, <tt>llvm.cttz(2) = 1</tt>.
5526</p>
5527</div>
5528
Reid Spencer497d93e2007-04-01 08:27:01 +00005529<!-- _______________________________________________________________________ -->
5530<div class="doc_subsubsection">
Reid Spencerbeacf662007-04-10 02:51:31 +00005531 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencera13ba7d2007-04-01 19:00:37 +00005532</div>
5533
5534<div class="doc_text">
5535
5536<h5>Syntax:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +00005537<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Reid Spencera13ba7d2007-04-01 19:00:37 +00005538on any integer bit width.
5539<pre>
Chandler Carruth69940402007-08-04 01:51:18 +00005540 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
5541 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencera13ba7d2007-04-01 19:00:37 +00005542</pre>
5543
5544<h5>Overview:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +00005545<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencera13ba7d2007-04-01 19:00:37 +00005546range of bits from an integer value and returns them in the same bit width as
5547the original value.</p>
5548
5549<h5>Arguments:</h5>
5550<p>The first argument, <tt>%val</tt> and the result may be integer types of
5551any bit width but they must have the same bit width. The second and third
Reid Spencera3e435f2007-04-04 02:42:35 +00005552arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +00005553
5554<h5>Semantics:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +00005555<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencera3e435f2007-04-04 02:42:35 +00005556of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
5557<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
5558operates in forward mode.</p>
5559<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
5560right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencera13ba7d2007-04-01 19:00:37 +00005561only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
5562<ol>
5563 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
5564 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
5565 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
5566 to determine the number of bits to retain.</li>
5567 <li>A mask of the retained bits is created by shifting a -1 value.</li>
5568 <li>The mask is ANDed with <tt>%val</tt> to produce the result.
5569</ol>
Reid Spencerd6a85b52007-05-14 16:14:57 +00005570<p>In reverse mode, a similar computation is made except that the bits are
5571returned in the reverse order. So, for example, if <tt>X</tt> has the value
5572<tt>i16 0x0ACF (101011001111)</tt> and we apply
5573<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
5574<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +00005575</div>
5576
Reid Spencerf86037f2007-04-11 23:23:49 +00005577<div class="doc_subsubsection">
5578 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
5579</div>
5580
5581<div class="doc_text">
5582
5583<h5>Syntax:</h5>
5584<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
5585on any integer bit width.
5586<pre>
Chandler Carruth69940402007-08-04 01:51:18 +00005587 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
5588 declare i29 @llvm.part.set.i29.i9 (i29 %val, i9 %repl, i32 %lo, i32 %hi)
Reid Spencerf86037f2007-04-11 23:23:49 +00005589</pre>
5590
5591<h5>Overview:</h5>
5592<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
5593of bits in an integer value with another integer value. It returns the integer
5594with the replaced bits.</p>
5595
5596<h5>Arguments:</h5>
5597<p>The first argument, <tt>%val</tt> and the result may be integer types of
5598any bit width but they must have the same bit width. <tt>%val</tt> is the value
5599whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
5600integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
5601type since they specify only a bit index.</p>
5602
5603<h5>Semantics:</h5>
5604<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
5605of operation: forwards and reverse. If <tt>%lo</tt> is greater than
5606<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
5607operates in forward mode.</p>
5608<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
5609truncating it down to the size of the replacement area or zero extending it
5610up to that size.</p>
5611<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5612are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5613in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
5614to the <tt>%hi</tt>th bit.
Reid Spencerc6749c42007-05-14 16:50:20 +00005615<p>In reverse mode, a similar computation is made except that the bits are
5616reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
5617<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.
Reid Spencerf86037f2007-04-11 23:23:49 +00005618<h5>Examples:</h5>
5619<pre>
Reid Spencerf0dbf642007-04-12 01:03:03 +00005620 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencerc6749c42007-05-14 16:50:20 +00005621 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5622 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5623 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerf0dbf642007-04-12 01:03:03 +00005624 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencerc8910842007-04-11 23:49:50 +00005625</pre>
Reid Spencerf86037f2007-04-11 23:23:49 +00005626</div>
5627
Chris Lattner8ff75902004-01-06 05:31:32 +00005628<!-- ======================================================================= -->
5629<div class="doc_subsection">
5630 <a name="int_debugger">Debugger Intrinsics</a>
5631</div>
5632
5633<div class="doc_text">
5634<p>
5635The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
5636are described in the <a
5637href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
5638Debugging</a> document.
5639</p>
5640</div>
5641
5642
Jim Laskeydd4ef1b2007-03-14 19:31:19 +00005643<!-- ======================================================================= -->
5644<div class="doc_subsection">
5645 <a name="int_eh">Exception Handling Intrinsics</a>
5646</div>
5647
5648<div class="doc_text">
5649<p> The LLVM exception handling intrinsics (which all start with
5650<tt>llvm.eh.</tt> prefix), are described in the <a
5651href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
5652Handling</a> document. </p>
5653</div>
5654
Tanya Lattner6d806e92007-06-15 20:50:54 +00005655<!-- ======================================================================= -->
5656<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +00005657 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +00005658</div>
5659
5660<div class="doc_text">
5661<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +00005662 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands36397f52007-07-27 12:58:54 +00005663 the <tt>nest</tt> attribute, from a function. The result is a callable
5664 function pointer lacking the nest parameter - the caller does not need
5665 to provide a value for it. Instead, the value to use is stored in
5666 advance in a "trampoline", a block of memory usually allocated
5667 on the stack, which also contains code to splice the nest value into the
5668 argument list. This is used to implement the GCC nested function address
5669 extension.
5670</p>
5671<p>
5672 For example, if the function is
5673 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
Bill Wendling03295ca2007-09-22 09:23:55 +00005674 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as follows:</p>
Duncan Sands36397f52007-07-27 12:58:54 +00005675<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +00005676 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
5677 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
5678 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
5679 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +00005680</pre>
Bill Wendling03295ca2007-09-22 09:23:55 +00005681 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
5682 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands36397f52007-07-27 12:58:54 +00005683</div>
5684
5685<!-- _______________________________________________________________________ -->
5686<div class="doc_subsubsection">
5687 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
5688</div>
5689<div class="doc_text">
5690<h5>Syntax:</h5>
5691<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +00005692declare i8* @llvm.init.trampoline(i8* &lt;tramp&gt;, i8* &lt;func&gt;, i8* &lt;nval&gt;)
Duncan Sands36397f52007-07-27 12:58:54 +00005693</pre>
5694<h5>Overview:</h5>
5695<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +00005696 This fills the memory pointed to by <tt>tramp</tt> with code
5697 and returns a function pointer suitable for executing it.
Duncan Sands36397f52007-07-27 12:58:54 +00005698</p>
5699<h5>Arguments:</h5>
5700<p>
5701 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
5702 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
5703 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsc00c2ba2007-08-22 23:39:54 +00005704 intrinsic. Note that the size and the alignment are target-specific - LLVM
5705 currently provides no portable way of determining them, so a front-end that
5706 generates this intrinsic needs to have some target-specific knowledge.
5707 The <tt>func</tt> argument must hold a function bitcast to an <tt>i8*</tt>.
Duncan Sands36397f52007-07-27 12:58:54 +00005708</p>
5709<h5>Semantics:</h5>
5710<p>
5711 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sandsf7331b32007-09-11 14:10:23 +00005712 dependent code, turning it into a function. A pointer to this function is
5713 returned, but needs to be bitcast to an
Duncan Sands36397f52007-07-27 12:58:54 +00005714 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sandsf7331b32007-09-11 14:10:23 +00005715 before being called. The new function's signature is the same as that of
5716 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
5717 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
5718 of pointer type. Calling the new function is equivalent to calling
5719 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
5720 missing <tt>nest</tt> argument. If, after calling
5721 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
5722 modified, then the effect of any later call to the returned function pointer is
5723 undefined.
Duncan Sands36397f52007-07-27 12:58:54 +00005724</p>
5725</div>
5726
5727<!-- ======================================================================= -->
5728<div class="doc_subsection">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +00005729 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
5730</div>
5731
5732<div class="doc_text">
5733<p>
5734 These intrinsic functions expand the "universal IR" of LLVM to represent
5735 hardware constructs for atomic operations and memory synchronization. This
5736 provides an interface to the hardware, not an interface to the programmer. It
Chris Lattnerd3eda892008-08-05 18:29:16 +00005737 is aimed at a low enough level to allow any programming models or APIs
5738 (Application Programming Interfaces) which
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +00005739 need atomic behaviors to map cleanly onto it. It is also modeled primarily on
5740 hardware behavior. Just as hardware provides a "universal IR" for source
5741 languages, it also provides a starting point for developing a "universal"
5742 atomic operation and synchronization IR.
5743</p>
5744<p>
5745 These do <em>not</em> form an API such as high-level threading libraries,
5746 software transaction memory systems, atomic primitives, and intrinsic
5747 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
5748 application libraries. The hardware interface provided by LLVM should allow
5749 a clean implementation of all of these APIs and parallel programming models.
5750 No one model or paradigm should be selected above others unless the hardware
5751 itself ubiquitously does so.
5752
5753</p>
5754</div>
5755
5756<!-- _______________________________________________________________________ -->
5757<div class="doc_subsubsection">
5758 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
5759</div>
5760<div class="doc_text">
5761<h5>Syntax:</h5>
5762<pre>
5763declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;,
5764i1 &lt;device&gt; )
5765
5766</pre>
5767<h5>Overview:</h5>
5768<p>
5769 The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
5770 specific pairs of memory access types.
5771</p>
5772<h5>Arguments:</h5>
5773<p>
5774 The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
5775 The first four arguments enables a specific barrier as listed below. The fith
5776 argument specifies that the barrier applies to io or device or uncached memory.
5777
5778</p>
5779 <ul>
5780 <li><tt>ll</tt>: load-load barrier</li>
5781 <li><tt>ls</tt>: load-store barrier</li>
5782 <li><tt>sl</tt>: store-load barrier</li>
5783 <li><tt>ss</tt>: store-store barrier</li>
5784 <li><tt>device</tt>: barrier applies to device and uncached memory also.
5785 </ul>
5786<h5>Semantics:</h5>
5787<p>
5788 This intrinsic causes the system to enforce some ordering constraints upon
5789 the loads and stores of the program. This barrier does not indicate
5790 <em>when</em> any events will occur, it only enforces an <em>order</em> in
5791 which they occur. For any of the specified pairs of load and store operations
5792 (f.ex. load-load, or store-load), all of the first operations preceding the
5793 barrier will complete before any of the second operations succeeding the
5794 barrier begin. Specifically the semantics for each pairing is as follows:
5795</p>
5796 <ul>
5797 <li><tt>ll</tt>: All loads before the barrier must complete before any load
5798 after the barrier begins.</li>
5799
5800 <li><tt>ls</tt>: All loads before the barrier must complete before any
5801 store after the barrier begins.</li>
5802 <li><tt>ss</tt>: All stores before the barrier must complete before any
5803 store after the barrier begins.</li>
5804 <li><tt>sl</tt>: All stores before the barrier must complete before any
5805 load after the barrier begins.</li>
5806 </ul>
5807<p>
5808 These semantics are applied with a logical "and" behavior when more than one
5809 is enabled in a single memory barrier intrinsic.
5810</p>
5811<p>
5812 Backends may implement stronger barriers than those requested when they do not
5813 support as fine grained a barrier as requested. Some architectures do not
5814 need all types of barriers and on such architectures, these become noops.
5815</p>
5816<h5>Example:</h5>
5817<pre>
5818%ptr = malloc i32
5819 store i32 4, %ptr
5820
5821%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
5822 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
5823 <i>; guarantee the above finishes</i>
5824 store i32 8, %ptr <i>; before this begins</i>
5825</pre>
5826</div>
5827
Andrew Lenharthab0b9492008-02-21 06:45:13 +00005828<!-- _______________________________________________________________________ -->
5829<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +00005830 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +00005831</div>
5832<div class="doc_text">
5833<h5>Syntax:</h5>
5834<p>
Mon P Wange3b3a722008-07-30 04:36:53 +00005835 This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
5836 any integer bit width and for different address spaces. Not all targets
5837 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +00005838
5839<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +00005840declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
5841declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
5842declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
5843declare 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 +00005844
5845</pre>
5846<h5>Overview:</h5>
5847<p>
5848 This loads a value in memory and compares it to a given value. If they are
5849 equal, it stores a new value into the memory.
5850</p>
5851<h5>Arguments:</h5>
5852<p>
Mon P Wang28873102008-06-25 08:15:39 +00005853 The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharthab0b9492008-02-21 06:45:13 +00005854 well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
5855 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
5856 this integer type. While any bit width integer may be used, targets may only
5857 lower representations they support in hardware.
5858
5859</p>
5860<h5>Semantics:</h5>
5861<p>
5862 This entire intrinsic must be executed atomically. It first loads the value
5863 in memory pointed to by <tt>ptr</tt> and compares it with the value
5864 <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
5865 loaded value is yielded in all cases. This provides the equivalent of an
5866 atomic compare-and-swap operation within the SSA framework.
5867</p>
5868<h5>Examples:</h5>
5869
5870<pre>
5871%ptr = malloc i32
5872 store i32 4, %ptr
5873
5874%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +00005875%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +00005876 <i>; yields {i32}:result1 = 4</i>
5877%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
5878%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
5879
5880%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +00005881%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +00005882 <i>; yields {i32}:result2 = 8</i>
5883%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
5884
5885%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
5886</pre>
5887</div>
5888
5889<!-- _______________________________________________________________________ -->
5890<div class="doc_subsubsection">
5891 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
5892</div>
5893<div class="doc_text">
5894<h5>Syntax:</h5>
5895
5896<p>
5897 This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
5898 integer bit width. Not all targets support all bit widths however.</p>
5899<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +00005900declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
5901declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
5902declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
5903declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharthab0b9492008-02-21 06:45:13 +00005904
5905</pre>
5906<h5>Overview:</h5>
5907<p>
5908 This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
5909 the value from memory. It then stores the value in <tt>val</tt> in the memory
5910 at <tt>ptr</tt>.
5911</p>
5912<h5>Arguments:</h5>
5913
5914<p>
Mon P Wang28873102008-06-25 08:15:39 +00005915 The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharthab0b9492008-02-21 06:45:13 +00005916 <tt>val</tt> argument and the result must be integers of the same bit width.
5917 The first argument, <tt>ptr</tt>, must be a pointer to a value of this
5918 integer type. The targets may only lower integer representations they
5919 support.
5920</p>
5921<h5>Semantics:</h5>
5922<p>
5923 This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
5924 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
5925 equivalent of an atomic swap operation within the SSA framework.
5926
5927</p>
5928<h5>Examples:</h5>
5929<pre>
5930%ptr = malloc i32
5931 store i32 4, %ptr
5932
5933%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +00005934%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +00005935 <i>; yields {i32}:result1 = 4</i>
5936%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
5937%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
5938
5939%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +00005940%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +00005941 <i>; yields {i32}:result2 = 8</i>
5942
5943%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
5944%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
5945</pre>
5946</div>
5947
5948<!-- _______________________________________________________________________ -->
5949<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +00005950 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +00005951
5952</div>
5953<div class="doc_text">
5954<h5>Syntax:</h5>
5955<p>
Mon P Wang28873102008-06-25 08:15:39 +00005956 This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on any
Andrew Lenharthab0b9492008-02-21 06:45:13 +00005957 integer bit width. Not all targets support all bit widths however.</p>
5958<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +00005959declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
5960declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
5961declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
5962declare i64 @llvm.atomic.load.add.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Andrew Lenharthab0b9492008-02-21 06:45:13 +00005963
5964</pre>
5965<h5>Overview:</h5>
5966<p>
5967 This intrinsic adds <tt>delta</tt> to the value stored in memory at
5968 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
5969</p>
5970<h5>Arguments:</h5>
5971<p>
5972
5973 The intrinsic takes two arguments, the first a pointer to an integer value
5974 and the second an integer value. The result is also an integer value. These
5975 integer types can have any bit width, but they must all have the same bit
5976 width. The targets may only lower integer representations they support.
5977</p>
5978<h5>Semantics:</h5>
5979<p>
5980 This intrinsic does a series of operations atomically. It first loads the
5981 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
5982 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
5983</p>
5984
5985<h5>Examples:</h5>
5986<pre>
5987%ptr = malloc i32
5988 store i32 4, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +00005989%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +00005990 <i>; yields {i32}:result1 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +00005991%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +00005992 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +00005993%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +00005994 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +00005995%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +00005996</pre>
5997</div>
5998
Mon P Wang28873102008-06-25 08:15:39 +00005999<!-- _______________________________________________________________________ -->
6000<div class="doc_subsubsection">
6001 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6002
6003</div>
6004<div class="doc_text">
6005<h5>Syntax:</h5>
6006<p>
6007 This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
Mon P Wange3b3a722008-07-30 04:36:53 +00006008 any integer bit width and for different address spaces. Not all targets
6009 support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +00006010<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +00006011declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6012declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6013declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6014declare i64 @llvm.atomic.load.sub.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +00006015
6016</pre>
6017<h5>Overview:</h5>
6018<p>
6019 This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6020 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6021</p>
6022<h5>Arguments:</h5>
6023<p>
6024
6025 The intrinsic takes two arguments, the first a pointer to an integer value
6026 and the second an integer value. The result is also an integer value. These
6027 integer types can have any bit width, but they must all have the same bit
6028 width. The targets may only lower integer representations they support.
6029</p>
6030<h5>Semantics:</h5>
6031<p>
6032 This intrinsic does a series of operations atomically. It first loads the
6033 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6034 result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6035</p>
6036
6037<h5>Examples:</h5>
6038<pre>
6039%ptr = malloc i32
6040 store i32 8, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +00006041%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang28873102008-06-25 08:15:39 +00006042 <i>; yields {i32}:result1 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +00006043%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang28873102008-06-25 08:15:39 +00006044 <i>; yields {i32}:result2 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +00006045%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang28873102008-06-25 08:15:39 +00006046 <i>; yields {i32}:result3 = 2</i>
6047%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6048</pre>
6049</div>
6050
6051<!-- _______________________________________________________________________ -->
6052<div class="doc_subsubsection">
6053 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6054 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6055 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6056 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
6057
6058</div>
6059<div class="doc_text">
6060<h5>Syntax:</h5>
6061<p>
6062 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
6063 <tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wange3b3a722008-07-30 04:36:53 +00006064 <tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
6065 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +00006066<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +00006067declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6068declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6069declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6070declare i64 @llvm.atomic.load.and.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +00006071
6072</pre>
6073
6074<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +00006075declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6076declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6077declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6078declare i64 @llvm.atomic.load.or.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +00006079
6080</pre>
6081
6082<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +00006083declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6084declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6085declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6086declare i64 @llvm.atomic.load.nand.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +00006087
6088</pre>
6089
6090<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +00006091declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6092declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6093declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6094declare i64 @llvm.atomic.load.xor.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +00006095
6096</pre>
6097<h5>Overview:</h5>
6098<p>
6099 These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6100 the value stored in memory at <tt>ptr</tt>. It yields the original value
6101 at <tt>ptr</tt>.
6102</p>
6103<h5>Arguments:</h5>
6104<p>
6105
6106 These intrinsics take two arguments, the first a pointer to an integer value
6107 and the second an integer value. The result is also an integer value. These
6108 integer types can have any bit width, but they must all have the same bit
6109 width. The targets may only lower integer representations they support.
6110</p>
6111<h5>Semantics:</h5>
6112<p>
6113 These intrinsics does a series of operations atomically. They first load the
6114 value stored at <tt>ptr</tt>. They then do the bitwise operation
6115 <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
6116 value stored at <tt>ptr</tt>.
6117</p>
6118
6119<h5>Examples:</h5>
6120<pre>
6121%ptr = malloc i32
6122 store i32 0x0F0F, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +00006123%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +00006124 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wange3b3a722008-07-30 04:36:53 +00006125%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +00006126 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +00006127%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +00006128 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +00006129%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +00006130 <i>; yields {i32}:result3 = FF</i>
6131%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6132</pre>
6133</div>
6134
6135
6136<!-- _______________________________________________________________________ -->
6137<div class="doc_subsubsection">
6138 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6139 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6140 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6141 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
6142
6143</div>
6144<div class="doc_text">
6145<h5>Syntax:</h5>
6146<p>
6147 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6148 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wange3b3a722008-07-30 04:36:53 +00006149 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6150 address spaces. Not all targets
Mon P Wang28873102008-06-25 08:15:39 +00006151 support all bit widths however.</p>
6152<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +00006153declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6154declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6155declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6156declare i64 @llvm.atomic.load.max.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +00006157
6158</pre>
6159
6160<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +00006161declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6162declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6163declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6164declare i64 @llvm.atomic.load.min.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +00006165
6166</pre>
6167
6168<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +00006169declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6170declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6171declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6172declare i64 @llvm.atomic.load.umax.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +00006173
6174</pre>
6175
6176<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +00006177declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6178declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6179declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6180declare i64 @llvm.atomic.load.umin.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +00006181
6182</pre>
6183<h5>Overview:</h5>
6184<p>
6185 These intrinsics takes the signed or unsigned minimum or maximum of
6186 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6187 original value at <tt>ptr</tt>.
6188</p>
6189<h5>Arguments:</h5>
6190<p>
6191
6192 These intrinsics take two arguments, the first a pointer to an integer value
6193 and the second an integer value. The result is also an integer value. These
6194 integer types can have any bit width, but they must all have the same bit
6195 width. The targets may only lower integer representations they support.
6196</p>
6197<h5>Semantics:</h5>
6198<p>
6199 These intrinsics does a series of operations atomically. They first load the
6200 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
6201 <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
6202 the original value stored at <tt>ptr</tt>.
6203</p>
6204
6205<h5>Examples:</h5>
6206<pre>
6207%ptr = malloc i32
6208 store i32 7, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +00006209%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang28873102008-06-25 08:15:39 +00006210 <i>; yields {i32}:result0 = 7</i>
Mon P Wange3b3a722008-07-30 04:36:53 +00006211%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang28873102008-06-25 08:15:39 +00006212 <i>; yields {i32}:result1 = -2</i>
Mon P Wange3b3a722008-07-30 04:36:53 +00006213%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang28873102008-06-25 08:15:39 +00006214 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +00006215%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang28873102008-06-25 08:15:39 +00006216 <i>; yields {i32}:result3 = 8</i>
6217%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6218</pre>
6219</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +00006220
6221<!-- ======================================================================= -->
6222<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +00006223 <a name="int_general">General Intrinsics</a>
6224</div>
6225
6226<div class="doc_text">
6227<p> This class of intrinsics is designed to be generic and has
6228no specific purpose. </p>
6229</div>
6230
6231<!-- _______________________________________________________________________ -->
6232<div class="doc_subsubsection">
6233 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6234</div>
6235
6236<div class="doc_text">
6237
6238<h5>Syntax:</h5>
6239<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +00006240 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 +00006241</pre>
6242
6243<h5>Overview:</h5>
6244
6245<p>
6246The '<tt>llvm.var.annotation</tt>' intrinsic
6247</p>
6248
6249<h5>Arguments:</h5>
6250
6251<p>
Tanya Lattnerd2e84422007-06-18 23:42:37 +00006252The first argument is a pointer to a value, the second is a pointer to a
6253global string, the third is a pointer to a global string which is the source
6254file name, and the last argument is the line number.
Tanya Lattner6d806e92007-06-15 20:50:54 +00006255</p>
6256
6257<h5>Semantics:</h5>
6258
6259<p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +00006260This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner6d806e92007-06-15 20:50:54 +00006261This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov4cb86182008-01-15 22:31:34 +00006262annotations. These have no other defined use, they are ignored by code
6263generation and optimization.
6264</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +00006265</div>
6266
Tanya Lattnerb6367882007-09-21 22:59:12 +00006267<!-- _______________________________________________________________________ -->
6268<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +00006269 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +00006270</div>
6271
6272<div class="doc_text">
6273
6274<h5>Syntax:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +00006275<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6276any integer bit width.
6277</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +00006278<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +00006279 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6280 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6281 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6282 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6283 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 +00006284</pre>
6285
6286<h5>Overview:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +00006287
6288<p>
6289The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattnerb6367882007-09-21 22:59:12 +00006290</p>
6291
6292<h5>Arguments:</h5>
6293
6294<p>
6295The first argument is an integer value (result of some expression),
6296the second is a pointer to a global string, the third is a pointer to a global
6297string which is the source file name, and the last argument is the line number.
Tanya Lattner39cfba62007-09-21 23:56:27 +00006298It returns the value of the first argument.
Tanya Lattnerb6367882007-09-21 22:59:12 +00006299</p>
6300
6301<h5>Semantics:</h5>
6302
6303<p>
6304This intrinsic allows annotations to be put on arbitrary expressions
6305with arbitrary strings. This can be useful for special purpose optimizations
6306that want to look for these annotations. These have no other defined use, they
6307are ignored by code generation and optimization.
6308</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +00006309
Anton Korobeynikov4cb86182008-01-15 22:31:34 +00006310<!-- _______________________________________________________________________ -->
6311<div class="doc_subsubsection">
6312 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6313</div>
6314
6315<div class="doc_text">
6316
6317<h5>Syntax:</h5>
6318<pre>
6319 declare void @llvm.trap()
6320</pre>
6321
6322<h5>Overview:</h5>
6323
6324<p>
6325The '<tt>llvm.trap</tt>' intrinsic
6326</p>
6327
6328<h5>Arguments:</h5>
6329
6330<p>
6331None
6332</p>
6333
6334<h5>Semantics:</h5>
6335
6336<p>
6337This intrinsics is lowered to the target dependent trap instruction. If the
6338target does not have a trap instruction, this intrinsic will be lowered to the
6339call of the abort() function.
6340</p>
6341</div>
6342
Chris Lattner00950542001-06-06 20:29:01 +00006343<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +00006344<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +00006345<address>
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6347 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
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Misha Brukmandaa4cb02004-03-01 17:47:27 +00006350
6351 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +00006352 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
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6354</address>
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