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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 7956412470b2e1f48c6be6fcd8e2363509358839 / . / docs / LangRef.html
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4<head>
5 <title>LLVM Assembly Language Reference Manual</title>
Reid Spencer3921c742004-08-26 20:44:00 +0000[diff] [blame]6 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
7 <meta name="author" content="Chris Lattner">
8 <meta name="description"
9 content="LLVM Assembly Language Reference Manual.">
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]10 <link rel="stylesheet" href="llvm.css" type="text/css">
11</head>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]14
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]15<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]16<ol>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]17 <li><a href="#abstract">Abstract</a></li>
18 <li><a href="#introduction">Introduction</a></li>
19 <li><a href="#identifiers">Identifiers</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]20 <li><a href="#highlevel">High Level Structure</a>
21 <ol>
22 <li><a href="#modulestructure">Module Structure</a></li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a></li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]24 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]25 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]26 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]27 <li><a href="#functionstructure">Functions</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]28 <li><a href="#aliasstructure">Aliases</a></li>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]29 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]30 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]31 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]32 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]33 <li><a href="#datalayout">Data Layout</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]34 </ol>
35 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]36 <li><a href="#typesystem">Type System</a>
37 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]38 <li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]39 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]40 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]41 <li><a href="#t_floating">Floating Point Types</a></li>
42 <li><a href="#t_void">Void Type</a></li>
43 <li><a href="#t_label">Label Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]44 </ol>
45 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]46 <li><a href="#t_derived">Derived Types</a>
47 <ol>
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]48 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]49 <li><a href="#t_array">Array Type</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]50 <li><a href="#t_function">Function Type</a></li>
51 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]52 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]53 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]54 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]55 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]56 </ol>
57 </li>
58 </ol>
59 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]60 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]61 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]62 <li><a href="#simpleconstants">Simple Constants</a></li>
63 <li><a href="#aggregateconstants">Aggregate Constants</a></li>
64 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
65 <li><a href="#undefvalues">Undefined Values</a></li>
66 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]67 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]68 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]69 <li><a href="#othervalues">Other Values</a>
70 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]71 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]72 </ol>
73 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]74 <li><a href="#instref">Instruction Reference</a>
75 <ol>
76 <li><a href="#terminators">Terminator Instructions</a>
77 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]78 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
79 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]80 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
81 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]82 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]83 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]84 </ol>
85 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]86 <li><a href="#binaryops">Binary Operations</a>
87 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]88 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
89 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
90 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]91 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
92 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
93 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]94 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
95 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
96 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]97 </ol>
98 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]99 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
100 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]101 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
102 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
103 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]104 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]105 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]106 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]107 </ol>
108 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]109 <li><a href="#vectorops">Vector Operations</a>
110 <ol>
111 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
112 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
113 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]114 </ol>
115 </li>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]116 <li><a href="#aggregateops">Aggregate Operations</a>
117 <ol>
118 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
119 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
120 </ol>
121 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]122 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]123 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]124 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
125 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
126 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]127 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
128 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
129 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]130 </ol>
131 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]132 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]133 <ol>
134 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
135 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
136 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
137 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
138 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]139 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
140 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
141 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
142 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]143 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
144 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]145 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]146 </ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]147 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]148 <li><a href="#otherops">Other Operations</a>
149 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]150 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
151 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]152 <li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
153 <li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]154 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]155 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]156 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]157 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]158 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]159 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]160 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]161 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]162 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]163 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]164 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
165 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]166 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
167 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
168 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]169 </ol>
170 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]171 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
172 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]173 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
174 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
175 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]176 </ol>
177 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]178 <li><a href="#int_codegen">Code Generator Intrinsics</a>
179 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]180 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
181 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
182 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
183 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
184 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
185 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
186 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]187 </ol>
188 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]189 <li><a href="#int_libc">Standard C Library Intrinsics</a>
190 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]191 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
192 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
193 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
194 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
195 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]196 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
197 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
198 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]199 </ol>
200 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]201 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]202 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]203 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]204 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
205 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
206 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]207 <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
208 <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]209 </ol>
210 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]211 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]212 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]213 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]214 <ol>
215 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]216 </ol>
217 </li>
Bill Wendling3c44f5b2008-11-18 22:10:53 +0000[diff] [blame]218 <li><a href="#int_atomics">Atomic intrinsics</a>
219 <ol>
220 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
221 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
222 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
223 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
224 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
225 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
226 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
227 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
228 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
229 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
230 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
231 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
232 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
233 </ol>
234 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]235 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]236 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]237 <li><a href="#int_var_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]238 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]239 <li><a href="#int_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]240 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]241 <li><a href="#int_trap">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]242 '<tt>llvm.trap</tt>' Intrinsic</a></li>
243 <li><a href="#int_stackprotector">
244 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]245 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]246 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]247 </ol>
248 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]249</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]250
251<div class="doc_author">
252 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
253 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]254</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]255
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]256<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]257<div class="doc_section"> <a name="abstract">Abstract </a></div>
258<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]259
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]260<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]261<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling837f39b2008-08-05 22:29:16 +0000[diff] [blame]262LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]263type safety, low-level operations, flexibility, and the capability of
264representing 'all' high-level languages cleanly. It is the common code
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]265representation used throughout all phases of the LLVM compilation
266strategy.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]267</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]268
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]269<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]270<div class="doc_section"> <a name="introduction">Introduction</a> </div>
271<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]272
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]273<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]274
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]275<p>The LLVM code representation is designed to be used in three
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]276different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]277representation (suitable for fast loading by a Just-In-Time compiler),
278and as a human readable assembly language representation. This allows
279LLVM to provide a powerful intermediate representation for efficient
280compiler transformations and analysis, while providing a natural means
281to debug and visualize the transformations. The three different forms
282of LLVM are all equivalent. This document describes the human readable
283representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]284
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]285<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]286while being expressive, typed, and extensible at the same time. It
287aims to be a "universal IR" of sorts, by being at a low enough level
288that high-level ideas may be cleanly mapped to it (similar to how
289microprocessors are "universal IR's", allowing many source languages to
290be mapped to them). By providing type information, LLVM can be used as
291the target of optimizations: for example, through pointer analysis, it
292can be proven that a C automatic variable is never accessed outside of
293the current function... allowing it to be promoted to a simple SSA
294value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]295
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]296</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]297
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]298<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]299<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]300
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]301<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]302
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]303<p>It is important to note that this document describes 'well formed'
304LLVM assembly language. There is a difference between what the parser
305accepts and what is considered 'well formed'. For example, the
306following instruction is syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]307
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]308<div class="doc_code">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]309<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]310%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]311</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]312</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]313
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]314<p>...because the definition of <tt>%x</tt> does not dominate all of
315its uses. The LLVM infrastructure provides a verification pass that may
316be used to verify that an LLVM module is well formed. This pass is
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]317automatically run by the parser after parsing input assembly and by
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]318the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]319by the verifier pass indicate bugs in transformation passes or input to
320the parser.</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]321</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]322
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]323<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]324
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]325<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]326<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]327<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]328
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]329<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]330
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]331 <p>LLVM identifiers come in two basic types: global and local. Global
332 identifiers (functions, global variables) begin with the @ character. Local
333 identifiers (register names, types) begin with the % character. Additionally,
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]334 there are three different formats for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]335
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]336<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]337 <li>Named values are represented as a string of characters with their prefix.
338 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
339 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]340 Identifiers which require other characters in their names can be surrounded
Daniel Dunbar76dea952008-10-14 23:51:43 +0000[diff] [blame]341 with quotes. Special characters may be escaped using "\xx" where xx is the
342 ASCII code for the character in hexadecimal. In this way, any character can
343 be used in a name value, even quotes themselves.
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]344
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]345 <li>Unnamed values are represented as an unsigned numeric value with their
346 prefix. For example, %12, @2, %44.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]347
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]348 <li>Constants, which are described in a <a href="#constants">section about
349 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]350</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]351
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]352<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]353don't need to worry about name clashes with reserved words, and the set of
354reserved words may be expanded in the future without penalty. Additionally,
355unnamed identifiers allow a compiler to quickly come up with a temporary
356variable without having to avoid symbol table conflicts.</p>
357
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]358<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]359languages. There are keywords for different opcodes
360('<tt><a href="#i_add">add</a></tt>',
361 '<tt><a href="#i_bitcast">bitcast</a></tt>',
362 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names ('<tt><a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]363href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]364and others. These reserved words cannot conflict with variable names, because
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]365none of them start with a prefix character ('%' or '@').</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]366
367<p>Here is an example of LLVM code to multiply the integer variable
368'<tt>%X</tt>' by 8:</p>
369
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]370<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]371
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]372<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]373<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]374%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]375</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]376</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]377
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]378<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]379
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]380<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]381<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]382%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]383</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]384</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]385
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]386<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]387
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]388<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]389<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]390<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
391<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
392%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]393</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]394</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]395
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]396<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
397important lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]398
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]399<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]400
401 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
402 line.</li>
403
404 <li>Unnamed temporaries are created when the result of a computation is not
405 assigned to a named value.</li>
406
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]407 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]408
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]409</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]410
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]411<p>...and it also shows a convention that we follow in this document. When
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]412demonstrating instructions, we will follow an instruction with a comment that
413defines the type and name of value produced. Comments are shown in italic
414text.</p>
415
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]416</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]417
418<!-- *********************************************************************** -->
419<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
420<!-- *********************************************************************** -->
421
422<!-- ======================================================================= -->
423<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
424</div>
425
426<div class="doc_text">
427
428<p>LLVM programs are composed of "Module"s, each of which is a
429translation unit of the input programs. Each module consists of
430functions, global variables, and symbol table entries. Modules may be
431combined together with the LLVM linker, which merges function (and
432global variable) definitions, resolves forward declarations, and merges
433symbol table entries. Here is an example of the "hello world" module:</p>
434
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]435<div class="doc_code">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]436<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]437<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
438 href="#globalvars">constant</a> <a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]439
440<i>; External declaration of the puts function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]441<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]442
443<i>; Definition of main function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]444define i32 @main() { <i>; i32()* </i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]445 <i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]446 %cast210 = <a
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]447 href="#i_getelementptr">getelementptr</a> [13 x i8]* @.LC0, i64 0, i64 0 <i>; i8 *</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]448
449 <i>; Call puts function to write out the string to stdout...</i>
450 <a
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]451 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]452 <a
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]453 href="#i_ret">ret</a> i32 0<br>}<br>
454</pre>
455</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]456
457<p>This example is made up of a <a href="#globalvars">global variable</a>
458named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
459function, and a <a href="#functionstructure">function definition</a>
460for "<tt>main</tt>".</p>
461
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]462<p>In general, a module is made up of a list of global values,
463where both functions and global variables are global values. Global values are
464represented by a pointer to a memory location (in this case, a pointer to an
465array of char, and a pointer to a function), and have one of the following <a
466href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]467
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]468</div>
469
470<!-- ======================================================================= -->
471<div class="doc_subsection">
472 <a name="linkage">Linkage Types</a>
473</div>
474
475<div class="doc_text">
476
477<p>
478All Global Variables and Functions have one of the following types of linkage:
479</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]480
481<dl>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]482
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]483 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]484
485 <dd>Global values with internal linkage are only directly accessible by
486 objects in the current module. In particular, linking code into a module with
487 an internal global value may cause the internal to be renamed as necessary to
488 avoid collisions. Because the symbol is internal to the module, all
489 references can be updated. This corresponds to the notion of the
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]490 '<tt>static</tt>' keyword in C.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]491 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]492
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]493 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]494
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]495 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
496 the same name when linkage occurs. This is typically used to implement
497 inline functions, templates, or other code which must be generated in each
498 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
499 allowed to be discarded.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]500 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]501
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]502 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
503
504 <dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
505 linkage, except that unreferenced <tt>common</tt> globals may not be
506 discarded. This is used for globals that may be emitted in multiple
507 translation units, but that are not guaranteed to be emitted into every
508 translation unit that uses them. One example of this is tentative
509 definitions in C, such as "<tt>int X;</tt>" at global scope.
510 </dd>
511
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]512 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]513
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]514 <dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
515 that some targets may choose to emit different assembly sequences for them
516 for target-dependent reasons. This is used for globals that are declared
517 "weak" in C source code.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]518 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]519
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]520 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]521
522 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
523 pointer to array type. When two global variables with appending linkage are
524 linked together, the two global arrays are appended together. This is the
525 LLVM, typesafe, equivalent of having the system linker append together
526 "sections" with identical names when .o files are linked.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]527 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]528
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]529 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]530 <dd>The semantics of this linkage follow the ELF object file model: the
531 symbol is weak until linked, if not linked, the symbol becomes null instead
532 of being an undefined reference.
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]533 </dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]534
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]535 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]536
537 <dd>If none of the above identifiers are used, the global is externally
538 visible, meaning that it participates in linkage and can be used to resolve
539 external symbol references.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]540 </dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]541</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]542
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]543 <p>
544 The next two types of linkage are targeted for Microsoft Windows platform
545 only. They are designed to support importing (exporting) symbols from (to)
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]546 DLLs (Dynamic Link Libraries).
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]547 </p>
548
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]549 <dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]550 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
551
552 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
553 or variable via a global pointer to a pointer that is set up by the DLL
554 exporting the symbol. On Microsoft Windows targets, the pointer name is
Dan Gohman79564122009-01-12 21:35:55 +0000[diff] [blame^]555 formed by combining <code>__imp_</code> and the function or variable name.
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]556 </dd>
557
558 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
559
560 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
561 pointer to a pointer in a DLL, so that it can be referenced with the
562 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
Dan Gohman79564122009-01-12 21:35:55 +0000[diff] [blame^]563 name is formed by combining <code>__imp_</code> and the function or variable
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]564 name.
565 </dd>
566
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]567</dl>
568
Dan Gohmanf0032762008-11-24 17:18:39 +0000[diff] [blame]569<p>For example, since the "<tt>.LC0</tt>"
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]570variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
571variable and was linked with this one, one of the two would be renamed,
572preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
573external (i.e., lacking any linkage declarations), they are accessible
Reid Spencerac8d2762007-01-05 00:59:10 +0000[diff] [blame]574outside of the current module.</p>
575<p>It is illegal for a function <i>declaration</i>
576to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]577or <tt>extern_weak</tt>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]578<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]579linkages.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]580</div>
581
582<!-- ======================================================================= -->
583<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]584 <a name="callingconv">Calling Conventions</a>
585</div>
586
587<div class="doc_text">
588
589<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
590and <a href="#i_invoke">invokes</a> can all have an optional calling convention
591specified for the call. The calling convention of any pair of dynamic
592caller/callee must match, or the behavior of the program is undefined. The
593following calling conventions are supported by LLVM, and more may be added in
594the future:</p>
595
596<dl>
597 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
598
599 <dd>This calling convention (the default if no other calling convention is
600 specified) matches the target C calling conventions. This calling convention
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]601 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencerc28d2bc2006-12-31 21:30:18 +0000[diff] [blame]602 prototype and implemented declaration of the function (as does normal C).
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]603 </dd>
604
605 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
606
607 <dd>This calling convention attempts to make calls as fast as possible
608 (e.g. by passing things in registers). This calling convention allows the
609 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]610 without having to conform to an externally specified ABI (Application Binary
611 Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer9097d142008-05-14 09:17:12 +0000[diff] [blame]612 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
613 supported. This calling convention does not support varargs and requires the
614 prototype of all callees to exactly match the prototype of the function
615 definition.
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]616 </dd>
617
618 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
619
620 <dd>This calling convention attempts to make code in the caller as efficient
621 as possible under the assumption that the call is not commonly executed. As
622 such, these calls often preserve all registers so that the call does not break
623 any live ranges in the caller side. This calling convention does not support
624 varargs and requires the prototype of all callees to exactly match the
625 prototype of the function definition.
626 </dd>
627
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]628 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]629
630 <dd>Any calling convention may be specified by number, allowing
631 target-specific calling conventions to be used. Target specific calling
632 conventions start at 64.
633 </dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]634</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]635
636<p>More calling conventions can be added/defined on an as-needed basis, to
637support pascal conventions or any other well-known target-independent
638convention.</p>
639
640</div>
641
642<!-- ======================================================================= -->
643<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]644 <a name="visibility">Visibility Styles</a>
645</div>
646
647<div class="doc_text">
648
649<p>
650All Global Variables and Functions have one of the following visibility styles:
651</p>
652
653<dl>
654 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
655
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]656 <dd>On targets that use the ELF object file format, default visibility means
657 that the declaration is visible to other
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]658 modules and, in shared libraries, means that the declared entity may be
659 overridden. On Darwin, default visibility means that the declaration is
660 visible to other modules. Default visibility corresponds to "external
661 linkage" in the language.
662 </dd>
663
664 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
665
666 <dd>Two declarations of an object with hidden visibility refer to the same
667 object if they are in the same shared object. Usually, hidden visibility
668 indicates that the symbol will not be placed into the dynamic symbol table,
669 so no other module (executable or shared library) can reference it
670 directly.
671 </dd>
672
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]673 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
674
675 <dd>On ELF, protected visibility indicates that the symbol will be placed in
676 the dynamic symbol table, but that references within the defining module will
677 bind to the local symbol. That is, the symbol cannot be overridden by another
678 module.
679 </dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]680</dl>
681
682</div>
683
684<!-- ======================================================================= -->
685<div class="doc_subsection">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]686 <a name="namedtypes">Named Types</a>
687</div>
688
689<div class="doc_text">
690
691<p>LLVM IR allows you to specify name aliases for certain types. This can make
692it easier to read the IR and make the IR more condensed (particularly when
693recursive types are involved). An example of a name specification is:
694</p>
695
696<div class="doc_code">
697<pre>
698%mytype = type { %mytype*, i32 }
699</pre>
700</div>
701
702<p>You may give a name to any <a href="#typesystem">type</a> except "<a
703href="t_void">void</a>". Type name aliases may be used anywhere a type is
704expected with the syntax "%mytype".</p>
705
706<p>Note that type names are aliases for the structural type that they indicate,
707and that you can therefore specify multiple names for the same type. This often
708leads to confusing behavior when dumping out a .ll file. Since LLVM IR uses
709structural typing, the name is not part of the type. When printing out LLVM IR,
710the printer will pick <em>one name</em> to render all types of a particular
711shape. This means that if you have code where two different source types end up
712having the same LLVM type, that the dumper will sometimes print the "wrong" or
713unexpected type. This is an important design point and isn't going to
714change.</p>
715
716</div>
717
718
719<!-- ======================================================================= -->
720<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]721 <a name="globalvars">Global Variables</a>
722</div>
723
724<div class="doc_text">
725
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]726<p>Global variables define regions of memory allocated at compilation time
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]727instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]728an explicit section to be placed in, and may have an optional explicit alignment
729specified. A variable may be defined as "thread_local", which means that it
730will not be shared by threads (each thread will have a separated copy of the
731variable). A variable may be defined as a global "constant," which indicates
732that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]733optimization, allowing the global data to be placed in the read-only section of
734an executable, etc). Note that variables that need runtime initialization
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]735cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]736
737<p>
738LLVM explicitly allows <em>declarations</em> of global variables to be marked
739constant, even if the final definition of the global is not. This capability
740can be used to enable slightly better optimization of the program, but requires
741the language definition to guarantee that optimizations based on the
742'constantness' are valid for the translation units that do not include the
743definition.
744</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]745
746<p>As SSA values, global variables define pointer values that are in
747scope (i.e. they dominate) all basic blocks in the program. Global
748variables always define a pointer to their "content" type because they
749describe a region of memory, and all memory objects in LLVM are
750accessed through pointers.</p>
751
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]752<p>A global variable may be declared to reside in a target-specifc numbered
753address space. For targets that support them, address spaces may affect how
754optimizations are performed and/or what target instructions are used to access
Christopher Lambd49e18d2007-12-12 08:44:39 +0000[diff] [blame]755the variable. The default address space is zero. The address space qualifier
756must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]757
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]758<p>LLVM allows an explicit section to be specified for globals. If the target
759supports it, it will emit globals to the section specified.</p>
760
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]761<p>An explicit alignment may be specified for a global. If not present, or if
762the alignment is set to zero, the alignment of the global is set by the target
763to whatever it feels convenient. If an explicit alignment is specified, the
764global is forced to have at least that much alignment. All alignments must be
765a power of 2.</p>
766
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]767<p>For example, the following defines a global in a numbered address space with
768an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]769
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]770<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]771<pre>
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]772@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]773</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]774</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]775
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]776</div>
777
778
779<!-- ======================================================================= -->
780<div class="doc_subsection">
781 <a name="functionstructure">Functions</a>
782</div>
783
784<div class="doc_text">
785
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]786<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
787an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]788<a href="#visibility">visibility style</a>, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]789<a href="#callingconv">calling convention</a>, a return type, an optional
790<a href="#paramattrs">parameter attribute</a> for the return type, a function
791name, a (possibly empty) argument list (each with optional
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]792<a href="#paramattrs">parameter attributes</a>), optional
793<a href="#fnattrs">function attributes</a>, an optional section,
794an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner0c46a7d2008-10-04 18:10:21 +0000[diff] [blame]795an opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]796
797LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
798optional <a href="#linkage">linkage type</a>, an optional
799<a href="#visibility">visibility style</a>, an optional
800<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]801<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]802name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksene754abe2007-12-10 03:30:21 +0000[diff] [blame]803<a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]804
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]805<p>A function definition contains a list of basic blocks, forming the CFG
806(Control Flow Graph) for
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]807the function. Each basic block may optionally start with a label (giving the
808basic block a symbol table entry), contains a list of instructions, and ends
809with a <a href="#terminators">terminator</a> instruction (such as a branch or
810function return).</p>
811
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]812<p>The first basic block in a function is special in two ways: it is immediately
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]813executed on entrance to the function, and it is not allowed to have predecessor
814basic blocks (i.e. there can not be any branches to the entry block of a
815function). Because the block can have no predecessors, it also cannot have any
816<a href="#i_phi">PHI nodes</a>.</p>
817
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]818<p>LLVM allows an explicit section to be specified for functions. If the target
819supports it, it will emit functions to the section specified.</p>
820
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]821<p>An explicit alignment may be specified for a function. If not present, or if
822the alignment is set to zero, the alignment of the function is set by the target
823to whatever it feels convenient. If an explicit alignment is specified, the
824function is forced to have at least that much alignment. All alignments must be
825a power of 2.</p>
826
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]827 <h5>Syntax:</h5>
828
829<div class="doc_code">
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]830<tt>
831define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
832 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
833 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
834 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
835 [<a href="#gc">gc</a>] { ... }
836</tt>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]837</div>
838
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]839</div>
840
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]841
842<!-- ======================================================================= -->
843<div class="doc_subsection">
844 <a name="aliasstructure">Aliases</a>
845</div>
846<div class="doc_text">
847 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov726d45c2008-03-22 08:36:14 +0000[diff] [blame]848 function, global variable, another alias or bitcast of global value). Aliases
849 may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]850 optional <a href="#visibility">visibility style</a>.</p>
851
852 <h5>Syntax:</h5>
853
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]854<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]855<pre>
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]856@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]857</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]858</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]859
860</div>
861
862
863
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]864<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]865<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
866<div class="doc_text">
867 <p>The return type and each parameter of a function type may have a set of
868 <i>parameter attributes</i> associated with them. Parameter attributes are
869 used to communicate additional information about the result or parameters of
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]870 a function. Parameter attributes are considered to be part of the function,
871 not of the function type, so functions with different parameter attributes
872 can have the same function type.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]873
Reid Spencer950e9f82007-01-15 18:27:39 +0000[diff] [blame]874 <p>Parameter attributes are simple keywords that follow the type specified. If
875 multiple parameter attributes are needed, they are space separated. For
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]876 example:</p>
877
878<div class="doc_code">
879<pre>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]880declare i32 @printf(i8* noalias , ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]881declare i32 @atoi(i8 zeroext)
882declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]883</pre>
884</div>
885
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]886 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
887 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]888
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]889 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]890 <dl>
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]891 <dt><tt>zeroext</tt></dt>
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]892 <dd>This indicates to the code generator that the parameter or return value
893 should be zero-extended to a 32-bit value by the caller (for a parameter)
894 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]895
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]896 <dt><tt>signext</tt></dt>
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]897 <dd>This indicates to the code generator that the parameter or return value
898 should be sign-extended to a 32-bit value by the caller (for a parameter)
899 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]900
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]901 <dt><tt>inreg</tt></dt>
Dale Johannesenc9c6da62008-09-25 20:47:45 +0000[diff] [blame]902 <dd>This indicates that this parameter or return value should be treated
903 in a special target-dependent fashion during while emitting code for a
904 function call or return (usually, by putting it in a register as opposed
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]905 to memory, though some targets use it to distinguish between two different
906 kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]907
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]908 <dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner0747baa2008-01-15 04:34:22 +0000[diff] [blame]909 <dd>This indicates that the pointer parameter should really be passed by
910 value to the function. The attribute implies that a hidden copy of the
911 pointee is made between the caller and the callee, so the callee is unable
Chris Lattnerebec6782008-08-05 18:21:08 +0000[diff] [blame]912 to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner0747baa2008-01-15 04:34:22 +0000[diff] [blame]913 pointer arguments. It is generally used to pass structs and arrays by
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]914 value, but is also valid on pointers to scalars. The copy is considered to
915 belong to the caller not the callee (for example,
916 <tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]917 <tt>byval</tt> parameters). This is not a valid attribute for return
918 values. </dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]919
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]920 <dt><tt>sret</tt></dt>
Duncan Sandse26dec62008-02-18 04:19:38 +0000[diff] [blame]921 <dd>This indicates that the pointer parameter specifies the address of a
922 structure that is the return value of the function in the source program.
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]923 This pointer must be guaranteed by the caller to be valid: loads and stores
924 to the structure may be assumed by the callee to not to trap. This may only
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]925 be applied to the first parameter. This is not a valid attribute for
926 return values. </dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]927
Zhou Shengfebca342007-06-05 05:28:26 +0000[diff] [blame]928 <dt><tt>noalias</tt></dt>
Nick Lewycky02ff3082008-11-24 03:41:24 +0000[diff] [blame]929 <dd>This indicates that the pointer does not alias any global or any other
930 parameter. The caller is responsible for ensuring that this is the
Nick Lewyckyb2b32fd2008-11-24 05:00:44 +0000[diff] [blame]931 case. On a function return value, <tt>noalias</tt> additionally indicates
932 that the pointer does not alias any other pointers visible to the
Nick Lewyckyf23d0d32008-12-19 06:39:12 +0000[diff] [blame]933 caller. For further details, please see the discussion of the NoAlias
934 response in
935 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
936 analysis</a>.</dd>
937
938 <dt><tt>nocapture</tt></dt>
939 <dd>This indicates that the callee does not make any copies of the pointer
940 that outlive the callee itself. This is not a valid attribute for return
941 values.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]942
Duncan Sands50f19f52007-07-27 19:57:41 +0000[diff] [blame]943 <dt><tt>nest</tt></dt>
Duncan Sands0789b8b2008-07-08 09:27:25 +0000[diff] [blame]944 <dd>This indicates that the pointer parameter can be excised using the
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]945 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
946 attribute for return values.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]947 </dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]948
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]949</div>
950
951<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]952<div class="doc_subsection">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]953 <a name="gc">Garbage Collector Names</a>
954</div>
955
956<div class="doc_text">
957<p>Each function may specify a garbage collector name, which is simply a
958string.</p>
959
960<div class="doc_code"><pre
961>define void @f() gc "name" { ...</pre></div>
962
963<p>The compiler declares the supported values of <i>name</i>. Specifying a
964collector which will cause the compiler to alter its output in order to support
965the named garbage collection algorithm.</p>
966</div>
967
968<!-- ======================================================================= -->
969<div class="doc_subsection">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]970 <a name="fnattrs">Function Attributes</a>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]971</div>
972
973<div class="doc_text">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]974
975<p>Function attributes are set to communicate additional information about
976 a function. Function attributes are considered to be part of the function,
977 not of the function type, so functions with different parameter attributes
978 can have the same function type.</p>
979
980 <p>Function attributes are simple keywords that follow the type specified. If
981 multiple attributes are needed, they are space separated. For
982 example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]983
984<div class="doc_code">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]985<pre>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]986define void @f() noinline { ... }
987define void @f() alwaysinline { ... }
988define void @f() alwaysinline optsize { ... }
989define void @f() optsize
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]990</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]991</div>
992
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]993<dl>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]994<dt><tt>alwaysinline</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]995<dd>This attribute indicates that the inliner should attempt to inline this
996function into callers whenever possible, ignoring any active inlining size
997threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]998
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]999<dt><tt>noinline</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1000<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner94b5f7d2008-10-05 17:14:59 +0000[diff] [blame]1001in any situation. This attribute may not be used together with the
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1002<tt>alwaysinline</tt> attribute.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1003
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1004<dt><tt>optsize</tt></dt>
Devang Patel66c6c652008-09-29 18:34:44 +0000[diff] [blame]1005<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1006make choices that keep the code size of this function low, and otherwise do
1007optimizations specifically to reduce code size.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1008
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1009<dt><tt>noreturn</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1010<dd>This function attribute indicates that the function never returns normally.
1011This produces undefined behavior at runtime if the function ever does
1012dynamically return.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1013
1014<dt><tt>nounwind</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1015<dd>This function attribute indicates that the function never returns with an
1016unwind or exceptional control flow. If the function does unwind, its runtime
1017behavior is undefined.</dd>
1018
1019<dt><tt>readnone</tt></dt>
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]1020<dd>This attribute indicates that the function computes its result (or the
1021exception it throws) based strictly on its arguments, without dereferencing any
1022pointer arguments or otherwise accessing any mutable state (e.g. memory, control
1023registers, etc) visible to caller functions. It does not write through any
1024pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
1025never changes any state visible to callers.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1026
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]1027<dt><tt><a name="readonly">readonly</a></tt></dt>
1028<dd>This attribute indicates that the function does not write through any
1029pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
1030or otherwise modify any state (e.g. memory, control registers, etc) visible to
1031caller functions. It may dereference pointer arguments and read state that may
1032be set in the caller. A readonly function always returns the same value (or
1033throws the same exception) when called with the same set of arguments and global
1034state.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1035
1036<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1037<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1038protector. It is in the form of a "canary"&mdash;a random value placed on the
1039stack before the local variables that's checked upon return from the function to
1040see if it has been overwritten. A heuristic is used to determine if a function
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1041needs stack protectors or not.
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1042
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1043<p>If a function that has an <tt>ssp</tt> attribute is inlined into a function
1044that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
1045have an <tt>ssp</tt> attribute.</p></dd>
1046
1047<dt><tt>sspreq</tt></dt>
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1048<dd>This attribute indicates that the function should <em>always</em> emit a
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1049stack smashing protector. This overrides the <tt><a href="#ssp">ssp</a></tt>
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1050function attribute.
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1051
1052<p>If a function that has an <tt>sspreq</tt> attribute is inlined into a
1053function that doesn't have an <tt>sspreq</tt> attribute or which has
1054an <tt>ssp</tt> attribute, then the resulting function will have
1055an <tt>sspreq</tt> attribute.</p></dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1056</dl>
1057
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1058</div>
1059
1060<!-- ======================================================================= -->
1061<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1062 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1063</div>
1064
1065<div class="doc_text">
1066<p>
1067Modules may contain "module-level inline asm" blocks, which corresponds to the
1068GCC "file scope inline asm" blocks. These blocks are internally concatenated by
1069LLVM and treated as a single unit, but may be separated in the .ll file if
1070desired. The syntax is very simple:
1071</p>
1072
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1073<div class="doc_code">
1074<pre>
1075module asm "inline asm code goes here"
1076module asm "more can go here"
1077</pre>
1078</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1079
1080<p>The strings can contain any character by escaping non-printable characters.
1081 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
1082 for the number.
1083</p>
1084
1085<p>
1086 The inline asm code is simply printed to the machine code .s file when
1087 assembly code is generated.
1088</p>
1089</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1090
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1091<!-- ======================================================================= -->
1092<div class="doc_subsection">
1093 <a name="datalayout">Data Layout</a>
1094</div>
1095
1096<div class="doc_text">
1097<p>A module may specify a target specific data layout string that specifies how
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]1098data is to be laid out in memory. The syntax for the data layout is simply:</p>
1099<pre> target datalayout = "<i>layout specification</i>"</pre>
1100<p>The <i>layout specification</i> consists of a list of specifications
1101separated by the minus sign character ('-'). Each specification starts with a
1102letter and may include other information after the letter to define some
1103aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1104<dl>
1105 <dt><tt>E</tt></dt>
1106 <dd>Specifies that the target lays out data in big-endian form. That is, the
1107 bits with the most significance have the lowest address location.</dd>
1108 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1109 <dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1110 the bits with the least significance have the lowest address location.</dd>
1111 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1112 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
1113 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
1114 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
1115 too.</dd>
1116 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1117 <dd>This specifies the alignment for an integer type of a given bit
1118 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1119 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1120 <dd>This specifies the alignment for a vector type of a given bit
1121 <i>size</i>.</dd>
1122 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1123 <dd>This specifies the alignment for a floating point type of a given bit
1124 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1125 (double).</dd>
1126 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1127 <dd>This specifies the alignment for an aggregate type of a given bit
1128 <i>size</i>.</dd>
1129</dl>
1130<p>When constructing the data layout for a given target, LLVM starts with a
1131default set of specifications which are then (possibly) overriden by the
1132specifications in the <tt>datalayout</tt> keyword. The default specifications
1133are given in this list:</p>
1134<ul>
1135 <li><tt>E</tt> - big endian</li>
1136 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1137 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1138 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1139 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1140 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1141 <li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1142 alignment of 64-bits</li>
1143 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1144 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1145 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1146 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1147 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
1148</ul>
Chris Lattnerebec6782008-08-05 18:21:08 +0000[diff] [blame]1149<p>When LLVM is determining the alignment for a given type, it uses the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1150following rules:</p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1151<ol>
1152 <li>If the type sought is an exact match for one of the specifications, that
1153 specification is used.</li>
1154 <li>If no match is found, and the type sought is an integer type, then the
1155 smallest integer type that is larger than the bitwidth of the sought type is
1156 used. If none of the specifications are larger than the bitwidth then the the
1157 largest integer type is used. For example, given the default specifications
1158 above, the i7 type will use the alignment of i8 (next largest) while both
1159 i65 and i256 will use the alignment of i64 (largest specified).</li>
1160 <li>If no match is found, and the type sought is a vector type, then the
1161 largest vector type that is smaller than the sought vector type will be used
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1162 as a fall back. This happens because &lt;128 x double&gt; can be implemented
1163 in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1164</ol>
1165</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1166
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1167<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1168<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1169<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1170
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1171<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1172
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1173<p>The LLVM type system is one of the most important features of the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1174intermediate representation. Being typed enables a number of
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1175optimizations to be performed on the intermediate representation directly,
1176without having to do
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1177extra analyses on the side before the transformation. A strong type
1178system makes it easier to read the generated code and enables novel
1179analyses and transformations that are not feasible to perform on normal
1180three address code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1181
1182</div>
1183
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1184<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1185<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1186Classifications</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1187<div class="doc_text">
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1188<p>The types fall into a few useful
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1189classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1190
1191<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1192 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1193 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1194 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1195 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1196 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1197 </tr>
1198 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1199 <td><a href="#t_floating">floating point</a></td>
1200 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1201 </tr>
1202 <tr>
1203 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1204 <td><a href="#t_integer">integer</a>,
1205 <a href="#t_floating">floating point</a>,
1206 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1207 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1208 <a href="#t_struct">structure</a>,
1209 <a href="#t_array">array</a>,
Dan Gohmanade5faa2008-05-23 22:50:26 +0000[diff] [blame]1210 <a href="#t_label">label</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1211 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1212 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1213 <tr>
1214 <td><a href="#t_primitive">primitive</a></td>
1215 <td><a href="#t_label">label</a>,
1216 <a href="#t_void">void</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1217 <a href="#t_floating">floating point</a>.</td>
1218 </tr>
1219 <tr>
1220 <td><a href="#t_derived">derived</a></td>
1221 <td><a href="#t_integer">integer</a>,
1222 <a href="#t_array">array</a>,
1223 <a href="#t_function">function</a>,
1224 <a href="#t_pointer">pointer</a>,
1225 <a href="#t_struct">structure</a>,
1226 <a href="#t_pstruct">packed structure</a>,
1227 <a href="#t_vector">vector</a>,
1228 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1229 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1230 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1231 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1232</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1233
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1234<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1235most important. Values of these types are the only ones which can be
1236produced by instructions, passed as arguments, or used as operands to
Dan Gohmanc4b49eb2008-05-23 21:53:15 +0000[diff] [blame]1237instructions.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1238</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1239
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1240<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1241<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1242
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1243<div class="doc_text">
1244<p>The primitive types are the fundamental building blocks of the LLVM
1245system.</p>
1246
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1247</div>
1248
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1249<!-- _______________________________________________________________________ -->
1250<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1251
1252<div class="doc_text">
1253 <table>
1254 <tbody>
1255 <tr><th>Type</th><th>Description</th></tr>
1256 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1257 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1258 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1259 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1260 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1261 </tbody>
1262 </table>
1263</div>
1264
1265<!-- _______________________________________________________________________ -->
1266<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1267
1268<div class="doc_text">
1269<h5>Overview:</h5>
1270<p>The void type does not represent any value and has no size.</p>
1271
1272<h5>Syntax:</h5>
1273
1274<pre>
1275 void
1276</pre>
1277</div>
1278
1279<!-- _______________________________________________________________________ -->
1280<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1281
1282<div class="doc_text">
1283<h5>Overview:</h5>
1284<p>The label type represents code labels.</p>
1285
1286<h5>Syntax:</h5>
1287
1288<pre>
1289 label
1290</pre>
1291</div>
1292
1293
1294<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1295<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1296
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1297<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1298
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1299<p>The real power in LLVM comes from the derived types in the system.
1300This is what allows a programmer to represent arrays, functions,
1301pointers, and other useful types. Note that these derived types may be
1302recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1303
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1304</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1305
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1306<!-- _______________________________________________________________________ -->
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1307<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1308
1309<div class="doc_text">
1310
1311<h5>Overview:</h5>
1312<p>The integer type is a very simple derived type that simply specifies an
1313arbitrary bit width for the integer type desired. Any bit width from 1 bit to
13142^23-1 (about 8 million) can be specified.</p>
1315
1316<h5>Syntax:</h5>
1317
1318<pre>
1319 iN
1320</pre>
1321
1322<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1323value.</p>
1324
1325<h5>Examples:</h5>
1326<table class="layout">
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]1327 <tbody>
1328 <tr>
1329 <td><tt>i1</tt></td>
1330 <td>a single-bit integer.</td>
1331 </tr><tr>
1332 <td><tt>i32</tt></td>
1333 <td>a 32-bit integer.</td>
1334 </tr><tr>
1335 <td><tt>i1942652</tt></td>
1336 <td>a really big integer of over 1 million bits.</td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1337 </tr>
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]1338 </tbody>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1339</table>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1340</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1341
1342<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1343<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1344
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1345<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1346
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1347<h5>Overview:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1348
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1349<p>The array type is a very simple derived type that arranges elements
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1350sequentially in memory. The array type requires a size (number of
1351elements) and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1352
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1353<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1354
1355<pre>
1356 [&lt;# elements&gt; x &lt;elementtype&gt;]
1357</pre>
1358
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1359<p>The number of elements is a constant integer value; elementtype may
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1360be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1361
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1362<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1363<table class="layout">
1364 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1365 <td class="left"><tt>[40 x i32]</tt></td>
1366 <td class="left">Array of 40 32-bit integer values.</td>
1367 </tr>
1368 <tr class="layout">
1369 <td class="left"><tt>[41 x i32]</tt></td>
1370 <td class="left">Array of 41 32-bit integer values.</td>
1371 </tr>
1372 <tr class="layout">
1373 <td class="left"><tt>[4 x i8]</tt></td>
1374 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1375 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1376</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1377<p>Here are some examples of multidimensional arrays:</p>
1378<table class="layout">
1379 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1380 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1381 <td class="left">3x4 array of 32-bit integer values.</td>
1382 </tr>
1383 <tr class="layout">
1384 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1385 <td class="left">12x10 array of single precision floating point values.</td>
1386 </tr>
1387 <tr class="layout">
1388 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1389 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1390 </tr>
1391</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1392
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1393<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1394length array. Normally, accesses past the end of an array are undefined in
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1395LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1396As a special case, however, zero length arrays are recognized to be variable
1397length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1398type "{ i32, [0 x float]}", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1399
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1400</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1401
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1402<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1403<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1404<div class="doc_text">
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1405
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1406<h5>Overview:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1407
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1408<p>The function type can be thought of as a function signature. It
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1409consists of a return type and a list of formal parameter types. The
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1410return type of a function type is a scalar type, a void type, or a struct type.
Devang Patel7a3ad1a2008-03-24 20:52:42 +0000[diff] [blame]1411If the return type is a struct type then all struct elements must be of first
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1412class types, and the struct must have at least one element.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1413
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1414<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1415
1416<pre>
1417 &lt;returntype list&gt; (&lt;parameter list&gt;)
1418</pre>
1419
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1420<p>...where '<tt>&lt;parameter list&gt;</tt>' is a comma-separated list of type
Misha Brukmanc24b7582004-08-12 20:16:08 +0000[diff] [blame]1421specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1422which indicates that the function takes a variable number of arguments.
1423Variable argument functions can access their arguments with the <a
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1424 href="#int_varargs">variable argument handling intrinsic</a> functions.
1425'<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1426<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1427
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1428<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1429<table class="layout">
1430 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1431 <td class="left"><tt>i32 (i32)</tt></td>
1432 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1433 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1434 </tr><tr class="layout">
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]1435 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1436 </tt></td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1437 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1438 an <tt>i16</tt> that should be sign extended and a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1439 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1440 <tt>float</tt>.
1441 </td>
1442 </tr><tr class="layout">
1443 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1444 <td class="left">A vararg function that takes at least one
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1445 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1446 which returns an integer. This is the signature for <tt>printf</tt> in
1447 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1448 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1449 </tr><tr class="layout">
1450 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukmanb0a57aa2008-11-27 06:41:20 +0000[diff] [blame]1451 <td class="left">A function taking an <tt>i32</tt>, returning two
1452 <tt>i32</tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1453 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1454 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1455</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1456
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1457</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1458<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1459<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1460<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1461<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1462<p>The structure type is used to represent a collection of data members
1463together in memory. The packing of the field types is defined to match
1464the ABI of the underlying processor. The elements of a structure may
1465be any type that has a size.</p>
1466<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1467and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1468field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1469instruction.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1470<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1471<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1472<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1473<table class="layout">
1474 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1475 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1476 <td class="left">A triple of three <tt>i32</tt> values</td>
1477 </tr><tr class="layout">
1478 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1479 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1480 second element is a <a href="#t_pointer">pointer</a> to a
1481 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1482 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1483 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1484</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1485</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1486
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1487<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1488<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1489</div>
1490<div class="doc_text">
1491<h5>Overview:</h5>
1492<p>The packed structure type is used to represent a collection of data members
1493together in memory. There is no padding between fields. Further, the alignment
1494of a packed structure is 1 byte. The elements of a packed structure may
1495be any type that has a size.</p>
1496<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1497and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1498field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1499instruction.</p>
1500<h5>Syntax:</h5>
1501<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1502<h5>Examples:</h5>
1503<table class="layout">
1504 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1505 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1506 <td class="left">A triple of three <tt>i32</tt> values</td>
1507 </tr><tr class="layout">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1508 <td class="left">
1509<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1510 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1511 second element is a <a href="#t_pointer">pointer</a> to a
1512 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1513 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1514 </tr>
1515</table>
1516</div>
1517
1518<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1519<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1520<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1521<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1522<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]1523reference to another object, which must live in memory. Pointer types may have
1524an optional address space attribute defining the target-specific numbered
1525address space where the pointed-to object resides. The default address space is
1526zero.</p>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1527<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1528<pre> &lt;type&gt; *<br></pre>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1529<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1530<table class="layout">
1531 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]1532 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1533 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1534 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1535 </tr>
1536 <tr class="layout">
1537 <td class="left"><tt>i32 (i32 *) *</tt></td>
1538 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1539 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1540 <tt>i32</tt>.</td>
1541 </tr>
1542 <tr class="layout">
1543 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1544 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1545 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1546 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1547</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1548</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1549
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1550<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1551<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1552<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1553
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1554<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1555
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1556<p>A vector type is a simple derived type that represents a vector
1557of elements. Vector types are used when multiple primitive data
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1558are operated in parallel using a single instruction (SIMD).
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1559A vector type requires a size (number of
Chris Lattnerb8d172f2005-11-10 01:44:22 +0000[diff] [blame]1560elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1561of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1562considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1563
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1564<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1565
1566<pre>
1567 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1568</pre>
1569
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1570<p>The number of elements is a constant integer value; elementtype may
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1571be any integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1572
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1573<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1574
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1575<table class="layout">
1576 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1577 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1578 <td class="left">Vector of 4 32-bit integer values.</td>
1579 </tr>
1580 <tr class="layout">
1581 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1582 <td class="left">Vector of 8 32-bit floating-point values.</td>
1583 </tr>
1584 <tr class="layout">
1585 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1586 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1587 </tr>
1588</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1589</div>
1590
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1591<!-- _______________________________________________________________________ -->
1592<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1593<div class="doc_text">
1594
1595<h5>Overview:</h5>
1596
1597<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksen8ac04ff2007-10-14 00:34:53 +0000[diff] [blame]1598corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1599In LLVM, opaque types can eventually be resolved to any type (not just a
1600structure type).</p>
1601
1602<h5>Syntax:</h5>
1603
1604<pre>
1605 opaque
1606</pre>
1607
1608<h5>Examples:</h5>
1609
1610<table class="layout">
1611 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1612 <td class="left"><tt>opaque</tt></td>
1613 <td class="left">An opaque type.</td>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1614 </tr>
1615</table>
1616</div>
1617
1618
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1619<!-- *********************************************************************** -->
1620<div class="doc_section"> <a name="constants">Constants</a> </div>
1621<!-- *********************************************************************** -->
1622
1623<div class="doc_text">
1624
1625<p>LLVM has several different basic types of constants. This section describes
1626them all and their syntax.</p>
1627
1628</div>
1629
1630<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1631<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1632
1633<div class="doc_text">
1634
1635<dl>
1636 <dt><b>Boolean constants</b></dt>
1637
1638 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1639 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1640 </dd>
1641
1642 <dt><b>Integer constants</b></dt>
1643
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1644 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1645 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1646 integer types.
1647 </dd>
1648
1649 <dt><b>Floating point constants</b></dt>
1650
1651 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1652 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]1653 notation (see below). The assembler requires the exact decimal value of
1654 a floating-point constant. For example, the assembler accepts 1.25 but
1655 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1656 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1657
1658 <dt><b>Null pointer constants</b></dt>
1659
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1660 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1661 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1662
1663</dl>
1664
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1665<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1666of floating point constants. For example, the form '<tt>double
16670x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
16684.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1669(and the only time that they are generated by the disassembler) is when a
1670floating point constant must be emitted but it cannot be represented as a
1671decimal floating point number. For example, NaN's, infinities, and other
1672special values are represented in their IEEE hexadecimal format so that
1673assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1674
1675</div>
1676
1677<!-- ======================================================================= -->
1678<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1679</div>
1680
1681<div class="doc_text">
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]1682<p>Aggregate constants arise from aggregation of simple constants
1683and smaller aggregate constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1684
1685<dl>
1686 <dt><b>Structure constants</b></dt>
1687
1688 <dd>Structure constants are represented with notation similar to structure
1689 type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner64910ee2007-12-25 20:34:52 +0000[diff] [blame]1690 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1691 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>". Structure constants
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]1692 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1693 types of elements must match those specified by the type.
1694 </dd>
1695
1696 <dt><b>Array constants</b></dt>
1697
1698 <dd>Array constants are represented with notation similar to array type
1699 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1700 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1701 constants must have <a href="#t_array">array type</a>, and the number and
1702 types of elements must match those specified by the type.
1703 </dd>
1704
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1705 <dt><b>Vector constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1706
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1707 <dd>Vector constants are represented with notation similar to vector type
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1708 definitions (a comma separated list of elements, surrounded by
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1709 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32 42,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1710 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1711 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1712 match those specified by the type.
1713 </dd>
1714
1715 <dt><b>Zero initialization</b></dt>
1716
1717 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1718 value to zero of <em>any</em> type, including scalar and aggregate types.
1719 This is often used to avoid having to print large zero initializers (e.g. for
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1720 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1721 initializers.
1722 </dd>
1723</dl>
1724
1725</div>
1726
1727<!-- ======================================================================= -->
1728<div class="doc_subsection">
1729 <a name="globalconstants">Global Variable and Function Addresses</a>
1730</div>
1731
1732<div class="doc_text">
1733
1734<p>The addresses of <a href="#globalvars">global variables</a> and <a
1735href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1736constants. These constants are explicitly referenced when the <a
1737href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1738href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1739file:</p>
1740
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1741<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1742<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]1743@X = global i32 17
1744@Y = global i32 42
1745@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1746</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1747</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1748
1749</div>
1750
1751<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1752<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1753<div class="doc_text">
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1754 <p>The string '<tt>undef</tt>' is recognized as a type-less constant that has
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1755 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1756 a constant is permitted.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1757
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1758 <p>Undefined values indicate to the compiler that the program is well defined
1759 no matter what value is used, giving the compiler more freedom to optimize.
1760 </p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1761</div>
1762
1763<!-- ======================================================================= -->
1764<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1765</div>
1766
1767<div class="doc_text">
1768
1769<p>Constant expressions are used to allow expressions involving other constants
1770to be used as constants. Constant expressions may be of any <a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1771href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1772that does not have side effects (e.g. load and call are not supported). The
1773following is the syntax for constant expressions:</p>
1774
1775<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1776 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1777 <dd>Truncate a constant to another type. The bit size of CST must be larger
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1778 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1779
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1780 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1781 <dd>Zero extend a constant to another type. The bit size of CST must be
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1782 smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1783
1784 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1785 <dd>Sign extend a constant to another type. The bit size of CST must be
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1786 smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1787
1788 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1789 <dd>Truncate a floating point constant to another floating point type. The
1790 size of CST must be larger than the size of TYPE. Both types must be
1791 floating point.</dd>
1792
1793 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1794 <dd>Floating point extend a constant to another type. The size of CST must be
1795 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1796
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]1797 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1798 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1799 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1800 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1801 of the same number of elements. If the value won't fit in the integer type,
1802 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1803
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1804 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1805 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1806 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1807 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1808 of the same number of elements. If the value won't fit in the integer type,
1809 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1810
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1811 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1812 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1813 constant. TYPE must be a scalar or vector floating point type. CST must be of
1814 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1815 of the same number of elements. If the value won't fit in the floating point
1816 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1817
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1818 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1819 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1820 constant. TYPE must be a scalar or vector floating point type. CST must be of
1821 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1822 of the same number of elements. If the value won't fit in the floating point
1823 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1824
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1825 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1826 <dd>Convert a pointer typed constant to the corresponding integer constant
1827 TYPE must be an integer type. CST must be of pointer type. The CST value is
1828 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1829
1830 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1831 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1832 pointer type. CST must be of integer type. The CST value is zero extended,
1833 truncated, or unchanged to make it fit in a pointer size. This one is
1834 <i>really</i> dangerous!</dd>
1835
1836 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1837 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1838 identical (same number of bits). The conversion is done as if the CST value
1839 was stored to memory and read back as TYPE. In other words, no bits change
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1840 with this operator, just the type. This can be used for conversion of
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1841 vector types to any other type, as long as they have the same bit width. For
Dan Gohman500233a2008-09-08 16:45:59 +0000[diff] [blame]1842 pointers it is only valid to cast to another pointer type. It is not valid
1843 to bitcast to or from an aggregate type.
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1844 </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1845
1846 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1847
1848 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1849 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1850 instruction, the index list may have zero or more indexes, which are required
1851 to make sense for the type of "CSTPTR".</dd>
1852
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1853 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1854
1855 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1856 constants.</dd>
1857
1858 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1859 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1860
1861 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1862 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1863
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]1864 <dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
1865 <dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
1866
1867 <dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
1868 <dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
1869
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1870 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1871
1872 <dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1873 operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1874
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1875 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1876
1877 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1878 operation</a> on constants.</dd>
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1879
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1880
1881 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1882
1883 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1884 operation</a> on constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1885
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1886 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1887
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1888 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1889 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1890 binary</a> operations. The constraints on operands are the same as those for
1891 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1892 values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1893</dl>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1894</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]1895
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1896<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1897<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1898<!-- *********************************************************************** -->
1899
1900<!-- ======================================================================= -->
1901<div class="doc_subsection">
1902<a name="inlineasm">Inline Assembler Expressions</a>
1903</div>
1904
1905<div class="doc_text">
1906
1907<p>
1908LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1909Module-Level Inline Assembly</a>) through the use of a special value. This
1910value represents the inline assembler as a string (containing the instructions
1911to emit), a list of operand constraints (stored as a string), and a flag that
1912indicates whether or not the inline asm expression has side effects. An example
1913inline assembler expression is:
1914</p>
1915
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1916<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1917<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1918i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1919</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1920</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1921
1922<p>
1923Inline assembler expressions may <b>only</b> be used as the callee operand of
1924a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
1925</p>
1926
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1927<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1928<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1929%X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y)
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1930</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1931</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1932
1933<p>
1934Inline asms with side effects not visible in the constraint list must be marked
1935as having side effects. This is done through the use of the
1936'<tt>sideeffect</tt>' keyword, like so:
1937</p>
1938
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1939<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1940<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1941call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1942</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1943</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1944
1945<p>TODO: The format of the asm and constraints string still need to be
1946documented here. Constraints on what can be done (e.g. duplication, moving, etc
Chris Lattner4f993352008-10-04 18:36:02 +0000[diff] [blame]1947need to be documented). This is probably best done by reference to another
1948document that covers inline asm from a holistic perspective.
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1949</p>
1950
1951</div>
1952
1953<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1954<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
1955<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1956
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1957<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1958
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1959<p>The LLVM instruction set consists of several different
1960classifications of instructions: <a href="#terminators">terminator
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1961instructions</a>, <a href="#binaryops">binary instructions</a>,
1962<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1963 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
1964instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1965
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1966</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1967
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1968<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1969<div class="doc_subsection"> <a name="terminators">Terminator
1970Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1971
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1972<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1973
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1974<p>As mentioned <a href="#functionstructure">previously</a>, every
1975basic block in a program ends with a "Terminator" instruction, which
1976indicates which block should be executed after the current block is
1977finished. These terminator instructions typically yield a '<tt>void</tt>'
1978value: they produce control flow, not values (the one exception being
1979the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1980<p>There are six different terminator instructions: the '<a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1981 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
1982instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1983the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
1984 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
1985 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1986
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1987</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1988
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1989<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1990<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
1991Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1992<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1993<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]1994<pre>
1995 ret &lt;type&gt; &lt;value&gt; <i>; Return a value from a non-void function</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1996 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1997</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1998
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1999<h5>Overview:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2000
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2001<p>The '<tt>ret</tt>' instruction is used to return control flow (and
2002optionally a value) from a function back to the caller.</p>
John Criswell4457dc92004-04-09 16:48:45 +0000[diff] [blame]2003<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2004returns a value and then causes control flow, and one that just causes
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2005control flow to occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2006
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2007<h5>Arguments:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2008
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2009<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
2010the return value. The type of the return value must be a
2011'<a href="#t_firstclass">first class</a>' type.</p>
2012
2013<p>A function is not <a href="#wellformed">well formed</a> if
2014it it has a non-void return type and contains a '<tt>ret</tt>'
2015instruction with no return value or a return value with a type that
2016does not match its type, or if it has a void return type and contains
2017a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2018
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2019<h5>Semantics:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2020
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2021<p>When the '<tt>ret</tt>' instruction is executed, control flow
2022returns back to the calling function's context. If the caller is a "<a
John Criswellfa081872004-06-25 15:16:57 +0000[diff] [blame]2023 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2024the instruction after the call. If the caller was an "<a
2025 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2026at the beginning of the "normal" destination block. If the instruction
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2027returns a value, that value shall set the call or invoke instruction's
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]2028return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2029
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2030<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2031
2032<pre>
2033 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2034 ret void <i>; Return from a void function</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2035 ret { i32, i8 } { i32 4, i8 2 } <i>; Return an aggregate of values 4 and 2</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2036</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2037</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2038<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2039<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2040<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2041<h5>Syntax:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2042<pre> br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;<br> br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2043</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2044<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2045<p>The '<tt>br</tt>' instruction is used to cause control flow to
2046transfer to a different basic block in the current function. There are
2047two forms of this instruction, corresponding to a conditional branch
2048and an unconditional branch.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2049<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2050<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2051single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]2052unconditional form of the '<tt>br</tt>' instruction takes a single
2053'<tt>label</tt>' value as a target.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2054<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2055<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2056argument is evaluated. If the value is <tt>true</tt>, control flows
2057to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2058control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2059<h5>Example:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2060<pre>Test:<br> %cond = <a href="#i_icmp">icmp</a> eq, i32 %a, %b<br> br i1 %cond, label %IfEqual, label %IfUnequal<br>IfEqual:<br> <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2061 href="#i_ret">ret</a> i32 1<br>IfUnequal:<br> <a href="#i_ret">ret</a> i32 0<br></pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2062</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2063<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2064<div class="doc_subsubsection">
2065 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2066</div>
2067
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2068<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2069<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2070
2071<pre>
2072 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2073</pre>
2074
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2075<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2076
2077<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
2078several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2079instruction, allowing a branch to occur to one of many possible
2080destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2081
2082
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2083<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2084
2085<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
2086comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
2087an array of pairs of comparison value constants and '<tt>label</tt>'s. The
2088table is not allowed to contain duplicate constant entries.</p>
2089
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2090<h5>Semantics:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2091
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2092<p>The <tt>switch</tt> instruction specifies a table of values and
2093destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]2094table is searched for the given value. If the value is found, control flow is
2095transfered to the corresponding destination; otherwise, control flow is
2096transfered to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2097
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2098<h5>Implementation:</h5>
2099
2100<p>Depending on properties of the target machine and the particular
2101<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]2102ways. For example, it could be generated as a series of chained conditional
2103branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2104
2105<h5>Example:</h5>
2106
2107<pre>
2108 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2109 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2110 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2111
2112 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2113 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2114
2115 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2116 switch i32 %val, label %otherwise [ i32 0, label %onzero
2117 i32 1, label %onone
2118 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2119</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2120</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2121
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2122<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2123<div class="doc_subsubsection">
2124 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2125</div>
2126
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2127<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2128
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2129<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2130
2131<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2132 &lt;result&gt; = invoke [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] &lt;ptr to function ty&gt; &lt;function ptr val&gt;(&lt;function args&gt;) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner76b8a332006-05-14 18:23:06 +0000[diff] [blame]2133 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2134</pre>
2135
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2136<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2137
2138<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
2139function, with the possibility of control flow transfer to either the
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2140'<tt>normal</tt>' label or the
2141'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2142"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
2143"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2144href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]2145continued at the dynamically nearest "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2146
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2147<h5>Arguments:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2148
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2149<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2150
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2151<ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2152 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]2153 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2154 convention</a> the call should use. If none is specified, the call defaults
2155 to using C calling conventions.
2156 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2157
2158 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
2159 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
2160 and '<tt>inreg</tt>' attributes are valid here.</li>
2161
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2162 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
2163 function value being invoked. In most cases, this is a direct function
2164 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
2165 an arbitrary pointer to function value.
2166 </li>
2167
2168 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
2169 function to be invoked. </li>
2170
2171 <li>'<tt>function args</tt>': argument list whose types match the function
2172 signature argument types. If the function signature indicates the function
2173 accepts a variable number of arguments, the extra arguments can be
2174 specified. </li>
2175
2176 <li>'<tt>normal label</tt>': the label reached when the called function
2177 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
2178
2179 <li>'<tt>exception label</tt>': the label reached when a callee returns with
2180 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
2181
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2182 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2183 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2184 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2185</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2186
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2187<h5>Semantics:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2188
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2189<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2190href="#i_call">call</a></tt>' instruction in most regards. The primary
2191difference is that it establishes an association with a label, which is used by
2192the runtime library to unwind the stack.</p>
2193
2194<p>This instruction is used in languages with destructors to ensure that proper
2195cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2196exception. Additionally, this is important for implementation of
2197'<tt>catch</tt>' clauses in high-level languages that support them.</p>
2198
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2199<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2200<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2201 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2202 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2203 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2204 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2205</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2206</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2207
2208
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2209<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2210
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2211<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2212Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2213
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2214<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2215
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2216<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2217<pre>
2218 unwind
2219</pre>
2220
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2221<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2222
2223<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
2224at the first callee in the dynamic call stack which used an <a
2225href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
2226primarily used to implement exception handling.</p>
2227
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2228<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2229
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]2230<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2231immediately halt. The dynamic call stack is then searched for the first <a
2232href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
2233execution continues at the "exceptional" destination block specified by the
2234<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
2235dynamic call chain, undefined behavior results.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2236</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2237
2238<!-- _______________________________________________________________________ -->
2239
2240<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2241Instruction</a> </div>
2242
2243<div class="doc_text">
2244
2245<h5>Syntax:</h5>
2246<pre>
2247 unreachable
2248</pre>
2249
2250<h5>Overview:</h5>
2251
2252<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
2253instruction is used to inform the optimizer that a particular portion of the
2254code is not reachable. This can be used to indicate that the code after a
2255no-return function cannot be reached, and other facts.</p>
2256
2257<h5>Semantics:</h5>
2258
2259<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
2260</div>
2261
2262
2263
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2264<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2265<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2266<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2267<p>Binary operators are used to do most of the computation in a
Chris Lattner5a158142008-04-01 18:47:32 +0000[diff] [blame]2268program. They require two operands of the same type, execute an operation on them, and
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2269produce a single value. The operands might represent
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2270multiple data, as is the case with the <a href="#t_vector">vector</a> data type.
Chris Lattner5a158142008-04-01 18:47:32 +0000[diff] [blame]2271The result value has the same type as its operands.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2272<p>There are several different binary operators:</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2273</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2274<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2275<div class="doc_subsubsection">
2276 <a name="i_add">'<tt>add</tt>' Instruction</a>
2277</div>
2278
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2279<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2280
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2281<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2282
2283<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2284 &lt;result&gt; = add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2285</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2286
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2287<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2288
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2289<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2290
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2291<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2292
2293<p>The two arguments to the '<tt>add</tt>' instruction must be <a
2294 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
2295 <a href="#t_vector">vector</a> values. Both arguments must have identical
2296 types.</p>
2297
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2298<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2299
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2300<p>The value produced is the integer or floating point sum of the two
2301operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2302
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2303<p>If an integer sum has unsigned overflow, the result returned is the
2304mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2305the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2306
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2307<p>Because LLVM integers use a two's complement representation, this
2308instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2309
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2310<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2311
2312<pre>
2313 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2314</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2315</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2316<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2317<div class="doc_subsubsection">
2318 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2319</div>
2320
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2321<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2322
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2323<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2324
2325<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2326 &lt;result&gt; = sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2327</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2328
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2329<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2330
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2331<p>The '<tt>sub</tt>' instruction returns the difference of its two
2332operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2333
2334<p>Note that the '<tt>sub</tt>' instruction is used to represent the
2335'<tt>neg</tt>' instruction present in most other intermediate
2336representations.</p>
2337
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2338<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2339
2340<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
2341 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2342 or <a href="#t_vector">vector</a> values. Both arguments must have identical
2343 types.</p>
2344
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2345<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2346
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2347<p>The value produced is the integer or floating point difference of
2348the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2349
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2350<p>If an integer difference has unsigned overflow, the result returned is the
2351mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2352the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2353
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2354<p>Because LLVM integers use a two's complement representation, this
2355instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2356
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2357<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2358<pre>
2359 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2360 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2361</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2362</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2363
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2364<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2365<div class="doc_subsubsection">
2366 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2367</div>
2368
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2369<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2370
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2371<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2372<pre> &lt;result&gt; = mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2373</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2374<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2375<p>The '<tt>mul</tt>' instruction returns the product of its two
2376operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2377
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2378<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2379
2380<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
2381href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2382or <a href="#t_vector">vector</a> values. Both arguments must have identical
2383types.</p>
2384
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2385<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2386
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2387<p>The value produced is the integer or floating point product of the
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2388two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2389
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2390<p>If the result of an integer multiplication has unsigned overflow,
2391the result returned is the mathematical result modulo
23922<sup>n</sup>, where n is the bit width of the result.</p>
2393<p>Because LLVM integers use a two's complement representation, and the
2394result is the same width as the operands, this instruction returns the
2395correct result for both signed and unsigned integers. If a full product
2396(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
2397should be sign-extended or zero-extended as appropriate to the
2398width of the full product.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2399<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2400<pre> &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2401</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2402</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2403
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2404<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2405<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2406</a></div>
2407<div class="doc_text">
2408<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2409<pre> &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2410</pre>
2411<h5>Overview:</h5>
2412<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2413operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2414
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2415<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2416
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2417<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2418<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2419values. Both arguments must have identical types.</p>
2420
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2421<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2422
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2423<p>The value produced is the unsigned integer quotient of the two operands.</p>
2424<p>Note that unsigned integer division and signed integer division are distinct
2425operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2426<p>Division by zero leads to undefined behavior.</p>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2427<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2428<pre> &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2429</pre>
2430</div>
2431<!-- _______________________________________________________________________ -->
2432<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2433</a> </div>
2434<div class="doc_text">
2435<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2436<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2437 &lt;result&gt; = sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2438</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2439
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2440<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2441
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2442<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2443operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2444
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2445<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2446
2447<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2448<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2449values. Both arguments must have identical types.</p>
2450
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2451<h5>Semantics:</h5>
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2452<p>The value produced is the signed integer quotient of the two operands rounded towards zero.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2453<p>Note that signed integer division and unsigned integer division are distinct
2454operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2455<p>Division by zero leads to undefined behavior. Overflow also leads to
2456undefined behavior; this is a rare case, but can occur, for example,
2457by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2458<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2459<pre> &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2460</pre>
2461</div>
2462<!-- _______________________________________________________________________ -->
2463<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2464Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2465<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2466<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2467<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2468 &lt;result&gt; = fdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2469</pre>
2470<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2471
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2472<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2473operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2474
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2475<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2476
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2477<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2478<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2479of floating point values. Both arguments must have identical types.</p>
2480
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2481<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2482
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2483<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2484
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2485<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2486
2487<pre>
2488 &lt;result&gt; = fdiv float 4.0, %var <i>; yields {float}:result = 4.0 / %var</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2489</pre>
2490</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2491
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2492<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2493<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2494</div>
2495<div class="doc_text">
2496<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2497<pre> &lt;result&gt; = urem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2498</pre>
2499<h5>Overview:</h5>
2500<p>The '<tt>urem</tt>' instruction returns the remainder from the
2501unsigned division of its two arguments.</p>
2502<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2503<p>The two arguments to the '<tt>urem</tt>' instruction must be
2504<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2505values. Both arguments must have identical types.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2506<h5>Semantics:</h5>
2507<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2508This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2509<p>Note that unsigned integer remainder and signed integer remainder are
2510distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
2511<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2512<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2513<pre> &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2514</pre>
2515
2516</div>
2517<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2518<div class="doc_subsubsection">
2519 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
2520</div>
2521
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2522<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2523
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2524<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2525
2526<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2527 &lt;result&gt; = srem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2528</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2529
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2530<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2531
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2532<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2533signed division of its two operands. This instruction can also take
2534<a href="#t_vector">vector</a> versions of the values in which case
2535the elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]2536
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2537<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2538
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2539<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2540<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2541values. Both arguments must have identical types.</p>
2542
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2543<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2544
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2545<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2546has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
2547operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2548a value. For more information about the difference, see <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2549 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2550Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencer64f5c6c2007-03-24 22:40:44 +0000[diff] [blame]2551please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2552Wikipedia: modulo operation</a>.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2553<p>Note that signed integer remainder and unsigned integer remainder are
2554distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
2555<p>Taking the remainder of a division by zero leads to undefined behavior.
2556Overflow also leads to undefined behavior; this is a rare case, but can occur,
2557for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
2558(The remainder doesn't actually overflow, but this rule lets srem be
2559implemented using instructions that return both the result of the division
2560and the remainder.)</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2561<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2562<pre> &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2563</pre>
2564
2565</div>
2566<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2567<div class="doc_subsubsection">
2568 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
2569
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2570<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2571
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2572<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2573<pre> &lt;result&gt; = frem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2574</pre>
2575<h5>Overview:</h5>
2576<p>The '<tt>frem</tt>' instruction returns the remainder from the
2577division of its two operands.</p>
2578<h5>Arguments:</h5>
2579<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2580<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2581of floating point values. Both arguments must have identical types.</p>
2582
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2583<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2584
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2585<p>This instruction returns the <i>remainder</i> of a division.
2586The remainder has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2587
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2588<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2589
2590<pre>
2591 &lt;result&gt; = frem float 4.0, %var <i>; yields {float}:result = 4.0 % %var</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2592</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2593</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]2594
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2595<!-- ======================================================================= -->
2596<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2597Operations</a> </div>
2598<div class="doc_text">
2599<p>Bitwise binary operators are used to do various forms of
2600bit-twiddling in a program. They are generally very efficient
2601instructions and can commonly be strength reduced from other
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2602instructions. They require two operands of the same type, execute an operation on them,
2603and produce a single value. The resulting value is the same type as its operands.</p>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2604</div>
2605
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2606<!-- _______________________________________________________________________ -->
2607<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2608Instruction</a> </div>
2609<div class="doc_text">
2610<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2611<pre> &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2612</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2613
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2614<h5>Overview:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2615
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2616<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2617the left a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2618
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2619<h5>Arguments:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2620
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2621<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2622 href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2623type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2624
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2625<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2626
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2627<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
2628where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
Mon P Wang01f8d092008-12-10 08:55:09 +0000[diff] [blame]2629equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
2630If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
2631corresponding shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2632
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2633<h5>Example:</h5><pre>
2634 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2635 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2636 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2637 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]2638 &lt;result&gt; = shl &lt;2 x i32&gt; &lt; i32 1, i32 1&gt;, &lt; i32 1, i32 2&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 2, i32 4&gt;</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2639</pre>
2640</div>
2641<!-- _______________________________________________________________________ -->
2642<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2643Instruction</a> </div>
2644<div class="doc_text">
2645<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2646<pre> &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2647</pre>
2648
2649<h5>Overview:</h5>
2650<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2651operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2652
2653<h5>Arguments:</h5>
2654<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2655<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2656type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2657
2658<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2659
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2660<p>This instruction always performs a logical shift right operation. The most
2661significant bits of the result will be filled with zero bits after the
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2662shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
Mon P Wang01f8d092008-12-10 08:55:09 +0000[diff] [blame]2663the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
2664vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
2665amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2666
2667<h5>Example:</h5>
2668<pre>
2669 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2670 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2671 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2672 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2673 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]2674 &lt;result&gt; = lshr &lt;2 x i32&gt; &lt; i32 -2, i32 4&gt;, &lt; i32 1, i32 2&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0x7FFFFFFF, i32 1&gt;</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2675</pre>
2676</div>
2677
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2678<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2679<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2680Instruction</a> </div>
2681<div class="doc_text">
2682
2683<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2684<pre> &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2685</pre>
2686
2687<h5>Overview:</h5>
2688<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2689operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2690
2691<h5>Arguments:</h5>
2692<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2693<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2694type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2695
2696<h5>Semantics:</h5>
2697<p>This instruction always performs an arithmetic shift right operation,
2698The most significant bits of the result will be filled with the sign bit
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2699of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
Mon P Wang01f8d092008-12-10 08:55:09 +0000[diff] [blame]2700larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
2701arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
2702corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2703
2704<h5>Example:</h5>
2705<pre>
2706 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2707 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2708 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2709 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2710 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]2711 &lt;result&gt; = ashr &lt;2 x i32&gt; &lt; i32 -2, i32 4&gt;, &lt; i32 1, i32 3&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 -1, i32 0&gt;</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2712</pre>
2713</div>
2714
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2715<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2716<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2717Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2718
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2719<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2720
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2721<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2722
2723<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2724 &lt;result&gt; = and &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2725</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2726
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2727<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2728
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2729<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2730its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2731
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2732<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2733
2734<p>The two arguments to the '<tt>and</tt>' instruction must be
2735<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2736values. Both arguments must have identical types.</p>
2737
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2738<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2739<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2740<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2741<div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2742<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2743 <tbody>
2744 <tr>
2745 <td>In0</td>
2746 <td>In1</td>
2747 <td>Out</td>
2748 </tr>
2749 <tr>
2750 <td>0</td>
2751 <td>0</td>
2752 <td>0</td>
2753 </tr>
2754 <tr>
2755 <td>0</td>
2756 <td>1</td>
2757 <td>0</td>
2758 </tr>
2759 <tr>
2760 <td>1</td>
2761 <td>0</td>
2762 <td>0</td>
2763 </tr>
2764 <tr>
2765 <td>1</td>
2766 <td>1</td>
2767 <td>1</td>
2768 </tr>
2769 </tbody>
2770</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2771</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2772<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2773<pre>
2774 &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2775 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2776 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2777</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2778</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2779<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2780<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2781<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2782<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2783<pre> &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2784</pre>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2785<h5>Overview:</h5>
2786<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2787or of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2788<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2789
2790<p>The two arguments to the '<tt>or</tt>' instruction must be
2791<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2792values. Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2793<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2794<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2795<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2796<div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2797<table border="1" cellspacing="0" cellpadding="4">
2798 <tbody>
2799 <tr>
2800 <td>In0</td>
2801 <td>In1</td>
2802 <td>Out</td>
2803 </tr>
2804 <tr>
2805 <td>0</td>
2806 <td>0</td>
2807 <td>0</td>
2808 </tr>
2809 <tr>
2810 <td>0</td>
2811 <td>1</td>
2812 <td>1</td>
2813 </tr>
2814 <tr>
2815 <td>1</td>
2816 <td>0</td>
2817 <td>1</td>
2818 </tr>
2819 <tr>
2820 <td>1</td>
2821 <td>1</td>
2822 <td>1</td>
2823 </tr>
2824 </tbody>
2825</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2826</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2827<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2828<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2829 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2830 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2831</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2832</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2833<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2834<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2835Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2836<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2837<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2838<pre> &lt;result&gt; = xor &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2839</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2840<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2841<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2842or of its two operands. The <tt>xor</tt> is used to implement the
2843"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2844<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2845<p>The two arguments to the '<tt>xor</tt>' instruction must be
2846<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2847values. Both arguments must have identical types.</p>
2848
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2849<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2850
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2851<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2852<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2853<div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2854<table border="1" cellspacing="0" cellpadding="4">
2855 <tbody>
2856 <tr>
2857 <td>In0</td>
2858 <td>In1</td>
2859 <td>Out</td>
2860 </tr>
2861 <tr>
2862 <td>0</td>
2863 <td>0</td>
2864 <td>0</td>
2865 </tr>
2866 <tr>
2867 <td>0</td>
2868 <td>1</td>
2869 <td>1</td>
2870 </tr>
2871 <tr>
2872 <td>1</td>
2873 <td>0</td>
2874 <td>1</td>
2875 </tr>
2876 <tr>
2877 <td>1</td>
2878 <td>1</td>
2879 <td>0</td>
2880 </tr>
2881 </tbody>
2882</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2883</div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2884<p> </p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2885<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2886<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2887 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2888 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2889 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2890</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2891</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2892
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2893<!-- ======================================================================= -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2894<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2895 <a name="vectorops">Vector Operations</a>
2896</div>
2897
2898<div class="doc_text">
2899
2900<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2901target-independent manner. These instructions cover the element-access and
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2902vector-specific operations needed to process vectors effectively. While LLVM
2903does directly support these vector operations, many sophisticated algorithms
2904will want to use target-specific intrinsics to take full advantage of a specific
2905target.</p>
2906
2907</div>
2908
2909<!-- _______________________________________________________________________ -->
2910<div class="doc_subsubsection">
2911 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
2912</div>
2913
2914<div class="doc_text">
2915
2916<h5>Syntax:</h5>
2917
2918<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2919 &lt;result&gt; = extractelement &lt;n x &lt;ty&gt;&gt; &lt;val&gt;, i32 &lt;idx&gt; <i>; yields &lt;ty&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2920</pre>
2921
2922<h5>Overview:</h5>
2923
2924<p>
2925The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2926element from a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2927</p>
2928
2929
2930<h5>Arguments:</h5>
2931
2932<p>
2933The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2934value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2935an index indicating the position from which to extract the element.
2936The index may be a variable.</p>
2937
2938<h5>Semantics:</h5>
2939
2940<p>
2941The result is a scalar of the same type as the element type of
2942<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
2943<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
2944results are undefined.
2945</p>
2946
2947<h5>Example:</h5>
2948
2949<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2950 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2951</pre>
2952</div>
2953
2954
2955<!-- _______________________________________________________________________ -->
2956<div class="doc_subsubsection">
2957 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
2958</div>
2959
2960<div class="doc_text">
2961
2962<h5>Syntax:</h5>
2963
2964<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]2965 &lt;result&gt; = insertelement &lt;n x &lt;ty&gt;&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, i32 &lt;idx&gt; <i>; yields &lt;n x &lt;ty&gt;&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2966</pre>
2967
2968<h5>Overview:</h5>
2969
2970<p>
2971The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2972element into a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2973</p>
2974
2975
2976<h5>Arguments:</h5>
2977
2978<p>
2979The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2980value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2981scalar value whose type must equal the element type of the first
2982operand. The third operand is an index indicating the position at
2983which to insert the value. The index may be a variable.</p>
2984
2985<h5>Semantics:</h5>
2986
2987<p>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2988The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2989element values are those of <tt>val</tt> except at position
2990<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
2991exceeds the length of <tt>val</tt>, the results are undefined.
2992</p>
2993
2994<h5>Example:</h5>
2995
2996<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2997 %result = insertelement &lt;4 x i32&gt; %vec, i32 1, i32 0 <i>; yields &lt;4 x i32&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2998</pre>
2999</div>
3000
3001<!-- _______________________________________________________________________ -->
3002<div class="doc_subsubsection">
3003 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3004</div>
3005
3006<div class="doc_text">
3007
3008<h5>Syntax:</h5>
3009
3010<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3011 &lt;result&gt; = shufflevector &lt;n x &lt;ty&gt;&gt; &lt;v1&gt;, &lt;n x &lt;ty&gt;&gt; &lt;v2&gt;, &lt;m x i32&gt; &lt;mask&gt; <i>; yields &lt;m x &lt;ty&gt;&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3012</pre>
3013
3014<h5>Overview:</h5>
3015
3016<p>
3017The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3018from two input vectors, returning a vector with the same element type as
3019the input and length that is the same as the shuffle mask.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3020</p>
3021
3022<h5>Arguments:</h5>
3023
3024<p>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3025The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
3026with types that match each other. The third argument is a shuffle mask whose
3027element type is always 'i32'. The result of the instruction is a vector whose
3028length is the same as the shuffle mask and whose element type is the same as
3029the element type of the first two operands.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3030</p>
3031
3032<p>
3033The shuffle mask operand is required to be a constant vector with either
3034constant integer or undef values.
3035</p>
3036
3037<h5>Semantics:</h5>
3038
3039<p>
3040The elements of the two input vectors are numbered from left to right across
3041both of the vectors. The shuffle mask operand specifies, for each element of
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3042the result vector, which element of the two input vectors the result element
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3043gets. The element selector may be undef (meaning "don't care") and the second
3044operand may be undef if performing a shuffle from only one vector.
3045</p>
3046
3047<h5>Example:</h5>
3048
3049<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3050 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3051 &lt;4 x i32&gt; &lt;i32 0, i32 4, i32 1, i32 5&gt; <i>; yields &lt;4 x i32&gt;</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3052 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
3053 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i> - Identity shuffle.
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3054 %result = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
3055 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
3056 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
3057 &lt;8 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7 &gt; <i>; yields &lt;8 x i32&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3058</pre>
3059</div>
3060
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]3061
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3062<!-- ======================================================================= -->
3063<div class="doc_subsection">
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3064 <a name="aggregateops">Aggregate Operations</a>
3065</div>
3066
3067<div class="doc_text">
3068
3069<p>LLVM supports several instructions for working with aggregate values.
3070</p>
3071
3072</div>
3073
3074<!-- _______________________________________________________________________ -->
3075<div class="doc_subsubsection">
3076 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3077</div>
3078
3079<div class="doc_text">
3080
3081<h5>Syntax:</h5>
3082
3083<pre>
3084 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3085</pre>
3086
3087<h5>Overview:</h5>
3088
3089<p>
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3090The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3091or array element from an aggregate value.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3092</p>
3093
3094
3095<h5>Arguments:</h5>
3096
3097<p>
3098The first operand of an '<tt>extractvalue</tt>' instruction is a
3099value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3100type. The operands are constant indices to specify which value to extract
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3101in a similar manner as indices in a
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3102'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3103</p>
3104
3105<h5>Semantics:</h5>
3106
3107<p>
3108The result is the value at the position in the aggregate specified by
3109the index operands.
3110</p>
3111
3112<h5>Example:</h5>
3113
3114<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3115 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3116</pre>
3117</div>
3118
3119
3120<!-- _______________________________________________________________________ -->
3121<div class="doc_subsubsection">
3122 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3123</div>
3124
3125<div class="doc_text">
3126
3127<h5>Syntax:</h5>
3128
3129<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3130 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;val&gt;, &lt;idx&gt; <i>; yields &lt;n x &lt;ty&gt;&gt;</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3131</pre>
3132
3133<h5>Overview:</h5>
3134
3135<p>
3136The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3137into a struct field or array element in an aggregate.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3138</p>
3139
3140
3141<h5>Arguments:</h5>
3142
3143<p>
3144The first operand of an '<tt>insertvalue</tt>' instruction is a
3145value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
3146The second operand is a first-class value to insert.
Dan Gohmanc4b49eb2008-05-23 21:53:15 +0000[diff] [blame]3147The following operands are constant indices
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3148indicating the position at which to insert the value in a similar manner as
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3149indices in a
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3150'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3151The value to insert must have the same type as the value identified
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3152by the indices.
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3153</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3154
3155<h5>Semantics:</h5>
3156
3157<p>
3158The result is an aggregate of the same type as <tt>val</tt>. Its
3159value is that of <tt>val</tt> except that the value at the position
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3160specified by the indices is that of <tt>elt</tt>.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3161</p>
3162
3163<h5>Example:</h5>
3164
3165<pre>
Dan Gohman52bb2db2008-06-23 15:26:37 +0000[diff] [blame]3166 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3167</pre>
3168</div>
3169
3170
3171<!-- ======================================================================= -->
3172<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3173 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3174</div>
3175
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3176<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3177
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3178<p>A key design point of an SSA-based representation is how it
3179represents memory. In LLVM, no memory locations are in SSA form, which
3180makes things very simple. This section describes how to read, write,
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3181allocate, and free memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3182
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3183</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3184
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3185<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3186<div class="doc_subsubsection">
3187 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3188</div>
3189
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3190<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3191
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3192<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3193
3194<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3195 &lt;result&gt; = malloc &lt;type&gt;[, i32 &lt;NumElements&gt;][, align &lt;alignment&gt;] <i>; yields {type*}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3196</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3197
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3198<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3199
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3200<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]3201heap and returns a pointer to it. The object is always allocated in the generic
3202address space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3203
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3204<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3205
3206<p>The '<tt>malloc</tt>' instruction allocates
3207<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswell6e4ca612004-02-24 16:13:56 +0000[diff] [blame]3208bytes of memory from the operating system and returns a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3209appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3210number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3211If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3212be aligned to at least that boundary. If not specified, or if zero, the target can
3213choose to align the allocation on any convenient boundary.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3214
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3215<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3216
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3217<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3218
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3219<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewycky02ff3082008-11-24 03:41:24 +0000[diff] [blame]3220a pointer is returned. The result of a zero byte allocation is undefined. The
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3221result is null if there is insufficient memory available.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3222
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3223<h5>Example:</h5>
3224
3225<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3226 %array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3227
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3228 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3229 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3230 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3231 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3232 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3233</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3234</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3235
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3236<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3237<div class="doc_subsubsection">
3238 <a name="i_free">'<tt>free</tt>' Instruction</a>
3239</div>
3240
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3241<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3242
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3243<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3244
3245<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3246 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3247</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3248
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3249<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3250
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3251<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]3252memory heap to be reallocated in the future.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3253
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3254<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3255
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3256<p>'<tt>value</tt>' shall be a pointer value that points to a value
3257that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
3258instruction.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3259
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3260<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3261
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3262<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattnere0db56d2008-04-19 22:41:32 +0000[diff] [blame]3263after this instruction executes. If the pointer is null, the operation
3264is a noop.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3265
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3266<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3267
3268<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3269 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3270 free [4 x i8]* %array
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3271</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3272</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3273
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3274<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3275<div class="doc_subsubsection">
3276 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3277</div>
3278
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3279<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3280
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3281<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3282
3283<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3284 &lt;result&gt; = alloca &lt;type&gt;[, i32 &lt;NumElements&gt;][, align &lt;alignment&gt;] <i>; yields {type*}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3285</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3286
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3287<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3288
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3289<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
3290currently executing function, to be automatically released when this function
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]3291returns to its caller. The object is always allocated in the generic address
3292space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3293
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3294<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3295
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3296<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3297bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3298appropriate type to the program. If "NumElements" is specified, it is the
3299number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3300If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3301to be aligned to at least that boundary. If not specified, or if zero, the target
3302can choose to align the allocation on any convenient boundary.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3303
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3304<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3305
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3306<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3307
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3308<p>Memory is allocated; a pointer is returned. The operation is undefiend if
3309there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3310memory is automatically released when the function returns. The '<tt>alloca</tt>'
3311instruction is commonly used to represent automatic variables that must
3312have an address available. When the function returns (either with the <tt><a
John Criswelldae2e932005-05-12 16:55:34 +0000[diff] [blame]3313 href="#i_ret">ret</a></tt> or <tt><a href="#i_unwind">unwind</a></tt>
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3314instructions), the memory is reclaimed. Allocating zero bytes
3315is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3316
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3317<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3318
3319<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3320 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
3321 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3322 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
3323 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3324</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3325</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3326
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3327<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3328<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3329Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3330<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3331<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]3332<pre> &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]<br> &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]<br></pre>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3333<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3334<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3335<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3336<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]3337address from which to load. The pointer must point to a <a
Chris Lattnere53e5082004-06-03 22:57:15 +0000[diff] [blame]3338 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]3339marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3340the number or order of execution of this <tt>load</tt> with other
3341volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3342instructions. </p>
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3343<p>
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3344The optional constant "align" argument specifies the alignment of the operation
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3345(that is, the alignment of the memory address). A value of 0 or an
3346omitted "align" argument means that the operation has the preferential
3347alignment for the target. It is the responsibility of the code emitter
3348to ensure that the alignment information is correct. Overestimating
3349the alignment results in an undefined behavior. Underestimating the
3350alignment may produce less efficient code. An alignment of 1 is always
3351safe.
3352</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3353<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3354<p>The location of memory pointed to is loaded.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3355<h5>Examples:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3356<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3357 <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3358 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
3359 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3360</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3361</div>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3362<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3363<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3364Instruction</a> </div>
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]3365<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3366<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]3367<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
3368 volatile store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3369</pre>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3370<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3371<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3372<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3373<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3374to store and an address at which to store it. The type of the '<tt>&lt;pointer&gt;</tt>'
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3375operand must be a pointer to the <a href="#t_firstclass">first class</a> type
3376of the '<tt>&lt;value&gt;</tt>'
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]3377operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3378optimizer is not allowed to modify the number or order of execution of
3379this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
3380 href="#i_store">store</a></tt> instructions.</p>
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3381<p>
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3382The optional constant "align" argument specifies the alignment of the operation
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3383(that is, the alignment of the memory address). A value of 0 or an
3384omitted "align" argument means that the operation has the preferential
3385alignment for the target. It is the responsibility of the code emitter
3386to ensure that the alignment information is correct. Overestimating
3387the alignment results in an undefined behavior. Underestimating the
3388alignment may produce less efficient code. An alignment of 1 is always
3389safe.
3390</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3391<h5>Semantics:</h5>
3392<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
3393at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3394<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3395<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]3396 store i32 3, i32* %ptr <i>; yields {void}</i>
3397 %val = <a href="#i_load">load</a> i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3398</pre>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3399</div>
3400
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3401<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3402<div class="doc_subsubsection">
3403 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3404</div>
3405
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3406<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3407<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3408<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3409 &lt;result&gt; = getelementptr &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3410</pre>
3411
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3412<h5>Overview:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3413
3414<p>
3415The '<tt>getelementptr</tt>' instruction is used to get the address of a
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3416subelement of an aggregate data structure. It performs address calculation only
3417and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3418
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3419<h5>Arguments:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3420
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3421<p>The first argument is always a pointer, and forms the basis of the
3422calculation. The remaining arguments are indices, that indicate which of the
3423elements of the aggregate object are indexed. The interpretation of each index
3424is dependent on the type being indexed into. The first index always indexes the
3425pointer value given as the first argument, the second index indexes a value of
3426the type pointed to (not necessarily the value directly pointed to, since the
3427first index can be non-zero), etc. The first type indexed into must be a pointer
3428value, subsequent types can be arrays, vectors and structs. Note that subsequent
3429types being indexed into can never be pointers, since that would require loading
3430the pointer before continuing calculation.</p>
3431
3432<p>The type of each index argument depends on the type it is indexing into.
3433When indexing into a (packed) structure, only <tt>i32</tt> integer
3434<b>constants</b> are allowed. When indexing into an array, pointer or vector,
3435only integers of 32 or 64 bits are allowed (also non-constants). 32-bit values
3436will be sign extended to 64-bits if required.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3437
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3438<p>For example, let's consider a C code fragment and how it gets
3439compiled to LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3440
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3441<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3442<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3443struct RT {
3444 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3445 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3446 char C;
3447};
3448struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3449 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3450 double Y;
3451 struct RT Z;
3452};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3453
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3454int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3455 return &amp;s[1].Z.B[5][13];
3456}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3457</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3458</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3459
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3460<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3461
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3462<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3463<pre>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]3464%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
3465%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3466
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3467define i32* %foo(%ST* %s) {
3468entry:
3469 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3470 ret i32* %reg
3471}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3472</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3473</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3474
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3475<h5>Semantics:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3476
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3477<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3478type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3479}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3480the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3481i8 }</tt>' type, another structure. The third index indexes into the second
3482element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3483array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3484'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
3485to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3486
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3487<p>Note that it is perfectly legal to index partially through a
3488structure, returning a pointer to an inner element. Because of this,
3489the LLVM code for the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3490
3491<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3492 define i32* %foo(%ST* %s) {
3493 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3494 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3495 %t3 = getelementptr %RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3496 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3497 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
3498 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3499 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3500</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3501
3502<p>Note that it is undefined to access an array out of bounds: array and
3503pointer indexes must always be within the defined bounds of the array type.
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]3504The one exception for this rule is zero length arrays. These arrays are
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3505defined to be accessible as variable length arrays, which requires access
3506beyond the zero'th element.</p>
3507
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3508<p>The getelementptr instruction is often confusing. For some more insight
3509into how it works, see <a href="GetElementPtr.html">the getelementptr
3510FAQ</a>.</p>
3511
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3512<h5>Example:</h5>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3513
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3514<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3515 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3516 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
3517 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3518 %vptr = getelementptr {i32, &lt;2 x i8&gt;}* %svptr, i64 0, i32 1, i32 1
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3519 <i>; yields i8*:eptr</i>
3520 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3521</pre>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3522</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3523
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3524<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3525<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3526</div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3527<div class="doc_text">
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3528<p>The instructions in this category are the conversion instructions (casting)
3529which all take a single operand and a type. They perform various bit conversions
3530on the operand.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3531</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3532
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3533<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3534<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3535 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
3536</div>
3537<div class="doc_text">
3538
3539<h5>Syntax:</h5>
3540<pre>
3541 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3542</pre>
3543
3544<h5>Overview:</h5>
3545<p>
3546The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
3547</p>
3548
3549<h5>Arguments:</h5>
3550<p>
3551The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
3552be an <a href="#t_integer">integer</a> type, and a type that specifies the size
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3553and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3554type. The bit size of <tt>value</tt> must be larger than the bit size of
3555<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3556
3557<h5>Semantics:</h5>
3558<p>
3559The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3560and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
3561larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
3562It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3563
3564<h5>Example:</h5>
3565<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3566 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3567 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
3568 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3569</pre>
3570</div>
3571
3572<!-- _______________________________________________________________________ -->
3573<div class="doc_subsubsection">
3574 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
3575</div>
3576<div class="doc_text">
3577
3578<h5>Syntax:</h5>
3579<pre>
3580 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3581</pre>
3582
3583<h5>Overview:</h5>
3584<p>The '<tt>zext</tt>' instruction zero extends its operand to type
3585<tt>ty2</tt>.</p>
3586
3587
3588<h5>Arguments:</h5>
3589<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3590<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3591also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3592<tt>value</tt> must be smaller than the bit size of the destination type,
3593<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3594
3595<h5>Semantics:</h5>
3596<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Chris Lattnerd1d25172007-05-24 19:13:27 +0000[diff] [blame]3597bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3598
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]3599<p>When zero extending from i1, the result will always be either 0 or 1.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3600
3601<h5>Example:</h5>
3602<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3603 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3604 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3605</pre>
3606</div>
3607
3608<!-- _______________________________________________________________________ -->
3609<div class="doc_subsubsection">
3610 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3611</div>
3612<div class="doc_text">
3613
3614<h5>Syntax:</h5>
3615<pre>
3616 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3617</pre>
3618
3619<h5>Overview:</h5>
3620<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3621
3622<h5>Arguments:</h5>
3623<p>
3624The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3625<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3626also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3627<tt>value</tt> must be smaller than the bit size of the destination type,
3628<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3629
3630<h5>Semantics:</h5>
3631<p>
3632The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3633bit (highest order bit) of the <tt>value</tt> until it reaches the bit size of
Chris Lattnerd1d25172007-05-24 19:13:27 +0000[diff] [blame]3634the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3635
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3636<p>When sign extending from i1, the extension always results in -1 or 0.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3637
3638<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3639<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3640 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3641 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3642</pre>
3643</div>
3644
3645<!-- _______________________________________________________________________ -->
3646<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3647 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3648</div>
3649
3650<div class="doc_text">
3651
3652<h5>Syntax:</h5>
3653
3654<pre>
3655 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3656</pre>
3657
3658<h5>Overview:</h5>
3659<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3660<tt>ty2</tt>.</p>
3661
3662
3663<h5>Arguments:</h5>
3664<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3665 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3666cast it to. The size of <tt>value</tt> must be larger than the size of
3667<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3668<i>no-op cast</i>.</p>
3669
3670<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3671<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3672<a href="#t_floating">floating point</a> type to a smaller
3673<a href="#t_floating">floating point</a> type. If the value cannot fit within
3674the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3675
3676<h5>Example:</h5>
3677<pre>
3678 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3679 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3680</pre>
3681</div>
3682
3683<!-- _______________________________________________________________________ -->
3684<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3685 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3686</div>
3687<div class="doc_text">
3688
3689<h5>Syntax:</h5>
3690<pre>
3691 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3692</pre>
3693
3694<h5>Overview:</h5>
3695<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3696floating point value.</p>
3697
3698<h5>Arguments:</h5>
3699<p>The '<tt>fpext</tt>' instruction takes a
3700<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3701and a <a href="#t_floating">floating point</a> type to cast it to. The source
3702type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3703
3704<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3705<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3706<a href="#t_floating">floating point</a> type to a larger
3707<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3708used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3709<tt>bitcast</tt> to make a <i>no-op cast</i> for a floating point cast.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3710
3711<h5>Example:</h5>
3712<pre>
3713 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3714 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3715</pre>
3716</div>
3717
3718<!-- _______________________________________________________________________ -->
3719<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]3720 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3721</div>
3722<div class="doc_text">
3723
3724<h5>Syntax:</h5>
3725<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3726 &lt;result&gt; = fptoui &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3727</pre>
3728
3729<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3730<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3731unsigned integer equivalent of type <tt>ty2</tt>.
3732</p>
3733
3734<h5>Arguments:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3735<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3736scalar or vector <a href="#t_floating">floating point</a> value, and a type
3737to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3738type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3739vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3740
3741<h5>Semantics:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3742<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3743<a href="#t_floating">floating point</a> operand into the nearest (rounding
3744towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3745the results are undefined.</p>
3746
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3747<h5>Example:</h5>
3748<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3749 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3750 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3751 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3752</pre>
3753</div>
3754
3755<!-- _______________________________________________________________________ -->
3756<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3757 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3758</div>
3759<div class="doc_text">
3760
3761<h5>Syntax:</h5>
3762<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3763 &lt;result&gt; = fptosi &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3764</pre>
3765
3766<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3767<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3768<a href="#t_floating">floating point</a> <tt>value</tt> to type <tt>ty2</tt>.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3769</p>
3770
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3771<h5>Arguments:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3772<p> The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3773scalar or vector <a href="#t_floating">floating point</a> value, and a type
3774to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3775type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3776vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3777
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3778<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3779<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3780<a href="#t_floating">floating point</a> operand into the nearest (rounding
3781towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3782the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3783
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3784<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3785<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3786 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3787 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3788 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3789</pre>
3790</div>
3791
3792<!-- _______________________________________________________________________ -->
3793<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3794 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3795</div>
3796<div class="doc_text">
3797
3798<h5>Syntax:</h5>
3799<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3800 &lt;result&gt; = uitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3801</pre>
3802
3803<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3804<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3805integer and converts that value to the <tt>ty2</tt> type.</p>
3806
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3807<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3808<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3809scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3810to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3811type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3812floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3813
3814<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3815<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3816integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3817the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3818
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3819<h5>Example:</h5>
3820<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3821 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3822 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3823</pre>
3824</div>
3825
3826<!-- _______________________________________________________________________ -->
3827<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3828 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3829</div>
3830<div class="doc_text">
3831
3832<h5>Syntax:</h5>
3833<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3834 &lt;result&gt; = sitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3835</pre>
3836
3837<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3838<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3839integer and converts that value to the <tt>ty2</tt> type.</p>
3840
3841<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3842<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3843scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3844to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3845type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3846floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3847
3848<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3849<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3850integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3851the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3852
3853<h5>Example:</h5>
3854<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3855 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3856 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3857</pre>
3858</div>
3859
3860<!-- _______________________________________________________________________ -->
3861<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3862 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3863</div>
3864<div class="doc_text">
3865
3866<h5>Syntax:</h5>
3867<pre>
3868 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3869</pre>
3870
3871<h5>Overview:</h5>
3872<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3873the integer type <tt>ty2</tt>.</p>
3874
3875<h5>Arguments:</h5>
3876<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3877must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3878<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3879
3880<h5>Semantics:</h5>
3881<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3882<tt>ty2</tt> by interpreting the pointer value as an integer and either
3883truncating or zero extending that value to the size of the integer type. If
3884<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3885<tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3886are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3887change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3888
3889<h5>Example:</h5>
3890<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3891 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3892 %Y = ptrtoint i32* %x to i64 <i>; yields zero extension on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3893</pre>
3894</div>
3895
3896<!-- _______________________________________________________________________ -->
3897<div class="doc_subsubsection">
3898 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3899</div>
3900<div class="doc_text">
3901
3902<h5>Syntax:</h5>
3903<pre>
3904 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3905</pre>
3906
3907<h5>Overview:</h5>
3908<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
3909a pointer type, <tt>ty2</tt>.</p>
3910
3911<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3912<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3913value to cast, and a type to cast it to, which must be a
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3914<a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3915
3916<h5>Semantics:</h5>
3917<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
3918<tt>ty2</tt> by applying either a zero extension or a truncation depending on
3919the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
3920size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
3921the size of a pointer then a zero extension is done. If they are the same size,
3922nothing is done (<i>no-op cast</i>).</p>
3923
3924<h5>Example:</h5>
3925<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3926 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
3927 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
3928 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3929</pre>
3930</div>
3931
3932<!-- _______________________________________________________________________ -->
3933<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3934 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3935</div>
3936<div class="doc_text">
3937
3938<h5>Syntax:</h5>
3939<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3940 &lt;result&gt; = bitcast &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3941</pre>
3942
3943<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3944
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3945<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3946<tt>ty2</tt> without changing any bits.</p>
3947
3948<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3949
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3950<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Dan Gohman500233a2008-09-08 16:45:59 +0000[diff] [blame]3951a non-aggregate first class value, and a type to cast it to, which must also be
3952a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
3953<tt>value</tt>
Reid Spencer19b569f2007-01-09 20:08:58 +0000[diff] [blame]3954and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3955type is a pointer, the destination type must also be a pointer. This
3956instruction supports bitwise conversion of vectors to integers and to vectors
3957of other types (as long as they have the same size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3958
3959<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3960<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3961<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
3962this conversion. The conversion is done as if the <tt>value</tt> had been
3963stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
3964converted to other pointer types with this instruction. To convert pointers to
3965other types, use the <a href="#i_inttoptr">inttoptr</a> or
3966<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3967
3968<h5>Example:</h5>
3969<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3970 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3971 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3972 %Z = bitcast &lt;2 x int&gt; %V to i64; <i>; yields i64: %V</i>
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3973</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3974</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3975
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3976<!-- ======================================================================= -->
3977<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
3978<div class="doc_text">
3979<p>The instructions in this category are the "miscellaneous"
3980instructions, which defy better classification.</p>
3981</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3982
3983<!-- _______________________________________________________________________ -->
3984<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
3985</div>
3986<div class="doc_text">
3987<h5>Syntax:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3988<pre> &lt;result&gt; = icmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt;}:result</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3989</pre>
3990<h5>Overview:</h5>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]3991<p>The '<tt>icmp</tt>' instruction returns a boolean value or
3992a vector of boolean values based on comparison
3993of its two integer, integer vector, or pointer operands.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3994<h5>Arguments:</h5>
3995<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3996the condition code indicating the kind of comparison to perform. It is not
3997a value, just a keyword. The possible condition code are:
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3998</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3999<ol>
4000 <li><tt>eq</tt>: equal</li>
4001 <li><tt>ne</tt>: not equal </li>
4002 <li><tt>ugt</tt>: unsigned greater than</li>
4003 <li><tt>uge</tt>: unsigned greater or equal</li>
4004 <li><tt>ult</tt>: unsigned less than</li>
4005 <li><tt>ule</tt>: unsigned less or equal</li>
4006 <li><tt>sgt</tt>: signed greater than</li>
4007 <li><tt>sge</tt>: signed greater or equal</li>
4008 <li><tt>slt</tt>: signed less than</li>
4009 <li><tt>sle</tt>: signed less or equal</li>
4010</ol>
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]4011<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4012<a href="#t_pointer">pointer</a>
4013or integer <a href="#t_vector">vector</a> typed.
4014They must also be identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4015<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4016<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4017the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4018yields either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt> result, as follows:
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4019</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4020<ol>
4021 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
4022 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
4023 </li>
4024 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4025 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4026 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4027 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4028 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4029 <tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4030 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4031 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4032 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4033 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4034 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4035 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4036 <li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4037 <tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4038 <li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4039 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4040 <li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4041 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4042</ol>
4043<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4044values are compared as if they were integers.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4045<p>If the operands are integer vectors, then they are compared
4046element by element. The result is an <tt>i1</tt> vector with
4047the same number of elements as the values being compared.
4048Otherwise, the result is an <tt>i1</tt>.
4049</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4050
4051<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4052<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
4053 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4054 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4055 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4056 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4057 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4058</pre>
4059</div>
4060
4061<!-- _______________________________________________________________________ -->
4062<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4063</div>
4064<div class="doc_text">
4065<h5>Syntax:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4066<pre> &lt;result&gt; = fcmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt;}:result</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4067</pre>
4068<h5>Overview:</h5>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4069<p>The '<tt>fcmp</tt>' instruction returns a boolean value
4070or vector of boolean values based on comparison
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4071of its operands.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4072<p>
4073If the operands are floating point scalars, then the result
4074type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
4075</p>
4076<p>If the operands are floating point vectors, then the result type
4077is a vector of boolean with the same number of elements as the
4078operands being compared.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4079<h5>Arguments:</h5>
4080<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4081the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4082a value, just a keyword. The possible condition code are:</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4083<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4084 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4085 <li><tt>oeq</tt>: ordered and equal</li>
4086 <li><tt>ogt</tt>: ordered and greater than </li>
4087 <li><tt>oge</tt>: ordered and greater than or equal</li>
4088 <li><tt>olt</tt>: ordered and less than </li>
4089 <li><tt>ole</tt>: ordered and less than or equal</li>
4090 <li><tt>one</tt>: ordered and not equal</li>
4091 <li><tt>ord</tt>: ordered (no nans)</li>
4092 <li><tt>ueq</tt>: unordered or equal</li>
4093 <li><tt>ugt</tt>: unordered or greater than </li>
4094 <li><tt>uge</tt>: unordered or greater than or equal</li>
4095 <li><tt>ult</tt>: unordered or less than </li>
4096 <li><tt>ule</tt>: unordered or less than or equal</li>
4097 <li><tt>une</tt>: unordered or not equal</li>
4098 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4099 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4100</ol>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4101<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer93a49852006-12-06 07:08:07 +0000[diff] [blame]4102<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4103<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
4104either a <a href="#t_floating">floating point</a> type
4105or a <a href="#t_vector">vector</a> of floating point type.
4106They must have identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4107<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4108<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4109according to the condition code given as <tt>cond</tt>.
4110If the operands are vectors, then the vectors are compared
4111element by element.
4112Each comparison performed
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4113always yields an <a href="#t_primitive">i1</a> result, as follows:</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4114<ol>
4115 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4116 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4117 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4118 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4119 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4120 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4121 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4122 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4123 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4124 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4125 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4126 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4127 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4128 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
4129 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4130 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4131 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4132 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4133 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4134 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4135 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4136 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4137 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4138 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4139 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4140 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4141 <li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4142 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4143</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4144
4145<h5>Example:</h5>
4146<pre> &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4147 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4148 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4149 &lt;result&gt; = fcmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4150</pre>
4151</div>
4152
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4153<!-- _______________________________________________________________________ -->
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4154<div class="doc_subsubsection">
4155 <a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
4156</div>
4157<div class="doc_text">
4158<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4159<pre> &lt;result&gt; = vicmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4160</pre>
4161<h5>Overview:</h5>
4162<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
4163element-wise comparison of its two integer vector operands.</p>
4164<h5>Arguments:</h5>
4165<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
4166the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4167a value, just a keyword. The possible condition code are:</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4168<ol>
4169 <li><tt>eq</tt>: equal</li>
4170 <li><tt>ne</tt>: not equal </li>
4171 <li><tt>ugt</tt>: unsigned greater than</li>
4172 <li><tt>uge</tt>: unsigned greater or equal</li>
4173 <li><tt>ult</tt>: unsigned less than</li>
4174 <li><tt>ule</tt>: unsigned less or equal</li>
4175 <li><tt>sgt</tt>: signed greater than</li>
4176 <li><tt>sge</tt>: signed greater or equal</li>
4177 <li><tt>slt</tt>: signed less than</li>
4178 <li><tt>sle</tt>: signed less or equal</li>
4179</ol>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4180<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4181<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
4182<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4183<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4184according to the condition code given as <tt>cond</tt>. The comparison yields a
4185<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
4186identical type as the values being compared. The most significant bit in each
4187element is 1 if the element-wise comparison evaluates to true, and is 0
4188otherwise. All other bits of the result are undefined. The condition codes
4189are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4190instruction</a>.</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4191
4192<h5>Example:</h5>
4193<pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4194 &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>
4195 &lt;result&gt; = vicmp ult &lt;2 x i8 &gt; &lt; i8 1, i8 2&gt;, &lt; i8 2, i8 2 &gt; <i>; yields: result=&lt;2 x i8&gt; &lt; i8 -1, i8 0 &gt;</i>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4196</pre>
4197</div>
4198
4199<!-- _______________________________________________________________________ -->
4200<div class="doc_subsubsection">
4201 <a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
4202</div>
4203<div class="doc_text">
4204<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4205<pre> &lt;result&gt; = vfcmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt;</pre>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4206<h5>Overview:</h5>
4207<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
4208element-wise comparison of its two floating point vector operands. The output
4209elements have the same width as the input elements.</p>
4210<h5>Arguments:</h5>
4211<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
4212the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4213a value, just a keyword. The possible condition code are:</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4214<ol>
4215 <li><tt>false</tt>: no comparison, always returns false</li>
4216 <li><tt>oeq</tt>: ordered and equal</li>
4217 <li><tt>ogt</tt>: ordered and greater than </li>
4218 <li><tt>oge</tt>: ordered and greater than or equal</li>
4219 <li><tt>olt</tt>: ordered and less than </li>
4220 <li><tt>ole</tt>: ordered and less than or equal</li>
4221 <li><tt>one</tt>: ordered and not equal</li>
4222 <li><tt>ord</tt>: ordered (no nans)</li>
4223 <li><tt>ueq</tt>: unordered or equal</li>
4224 <li><tt>ugt</tt>: unordered or greater than </li>
4225 <li><tt>uge</tt>: unordered or greater than or equal</li>
4226 <li><tt>ult</tt>: unordered or less than </li>
4227 <li><tt>ule</tt>: unordered or less than or equal</li>
4228 <li><tt>une</tt>: unordered or not equal</li>
4229 <li><tt>uno</tt>: unordered (either nans)</li>
4230 <li><tt>true</tt>: no comparison, always returns true</li>
4231</ol>
4232<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
4233<a href="#t_floating">floating point</a> typed. They must also be identical
4234types.</p>
4235<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4236<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4237according to the condition code given as <tt>cond</tt>. The comparison yields a
4238<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
4239an identical number of elements as the values being compared, and each element
4240having identical with to the width of the floating point elements. The most
4241significant bit in each element is 1 if the element-wise comparison evaluates to
4242true, and is 0 otherwise. All other bits of the result are undefined. The
4243condition codes are evaluated identically to the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4244<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4245
4246<h5>Example:</h5>
4247<pre>
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]4248 <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0, i32 -1 &gt;</i>
4249 &lt;result&gt; = vfcmp oeq &lt;2 x float&gt; &lt; float 4, float 0 &gt;, &lt; float 5, float 0 &gt;
4250
4251 <i>; yields: result=&lt;2 x i64&gt; &lt; i64 -1, i64 0 &gt;</i>
4252 &lt;result&gt; = vfcmp ult &lt;2 x double&gt; &lt; double 1, double 2 &gt;, &lt; double 2, double 2&gt;
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4253</pre>
4254</div>
4255
4256<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4257<div class="doc_subsubsection">
4258 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4259</div>
4260
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4261<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4262
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4263<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4264
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4265<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
4266<h5>Overview:</h5>
4267<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
4268the SSA graph representing the function.</p>
4269<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4270
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4271<p>The type of the incoming values is specified with the first type
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4272field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
4273as arguments, with one pair for each predecessor basic block of the
4274current block. Only values of <a href="#t_firstclass">first class</a>
4275type may be used as the value arguments to the PHI node. Only labels
4276may be used as the label arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4277
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4278<p>There must be no non-phi instructions between the start of a basic
4279block and the PHI instructions: i.e. PHI instructions must be first in
4280a basic block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4281
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4282<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4283
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4284<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
4285specified by the pair corresponding to the predecessor basic block that executed
4286just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4287
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4288<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4289<pre>
4290Loop: ; Infinite loop that counts from 0 on up...
4291 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4292 %nextindvar = add i32 %indvar, 1
4293 br label %Loop
4294</pre>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4295</div>
4296
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4297<!-- _______________________________________________________________________ -->
4298<div class="doc_subsubsection">
4299 <a name="i_select">'<tt>select</tt>' Instruction</a>
4300</div>
4301
4302<div class="doc_text">
4303
4304<h5>Syntax:</h5>
4305
4306<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4307 &lt;result&gt; = select <i>selty</i> &lt;cond&gt;, &lt;ty&gt; &lt;val1&gt;, &lt;ty&gt; &lt;val2&gt; <i>; yields ty</i>
4308
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4309 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4310</pre>
4311
4312<h5>Overview:</h5>
4313
4314<p>
4315The '<tt>select</tt>' instruction is used to choose one value based on a
4316condition, without branching.
4317</p>
4318
4319
4320<h5>Arguments:</h5>
4321
4322<p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4323The '<tt>select</tt>' instruction requires an 'i1' value or
4324a vector of 'i1' values indicating the
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4325condition, and two values of the same <a href="#t_firstclass">first class</a>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4326type. If the val1/val2 are vectors and
4327the condition is a scalar, then entire vectors are selected, not
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4328individual elements.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4329</p>
4330
4331<h5>Semantics:</h5>
4332
4333<p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4334If the condition is an i1 and it evaluates to 1, the instruction returns the first
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4335value argument; otherwise, it returns the second value argument.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4336</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4337<p>
4338If the condition is a vector of i1, then the value arguments must
4339be vectors of the same size, and the selection is done element
4340by element.
4341</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4342
4343<h5>Example:</h5>
4344
4345<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4346 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4347</pre>
4348</div>
4349
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]4350
4351<!-- _______________________________________________________________________ -->
4352<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4353 <a name="i_call">'<tt>call</tt>' Instruction</a>
4354</div>
4355
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4356<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4357
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4358<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4359<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]4360 &lt;result&gt; = [tail] call [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] &lt;ty&gt; [&lt;fnty&gt;*] &lt;fnptrval&gt;(&lt;function args&gt;) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4361</pre>
4362
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4363<h5>Overview:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4364
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4365<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4366
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4367<h5>Arguments:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4368
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4369<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4370
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4371<ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4372 <li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4373 <p>The optional "tail" marker indicates whether the callee function accesses
4374 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4375 function call is eligible for tail call optimization. Note that calls may
4376 be marked "tail" even if they do not occur before a <a
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4377 href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4378 </li>
4379 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4380 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4381 convention</a> the call should use. If none is specified, the call defaults
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4382 to using C calling conventions.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4383 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4384
4385 <li>
4386 <p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4387 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
4388 and '<tt>inreg</tt>' attributes are valid here.</p>
4389 </li>
4390
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4391 <li>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4392 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
4393 the type of the return value. Functions that return no value are marked
4394 <tt><a href="#t_void">void</a></tt>.</p>
4395 </li>
4396 <li>
4397 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
4398 value being invoked. The argument types must match the types implied by
4399 this signature. This type can be omitted if the function is not varargs
4400 and if the function type does not return a pointer to a function.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4401 </li>
4402 <li>
4403 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4404 be invoked. In most cases, this is a direct function invocation, but
4405 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4406 to function value.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4407 </li>
4408 <li>
4409 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencera7e302a2005-05-01 22:22:57 +0000[diff] [blame]4410 function signature argument types. All arguments must be of
4411 <a href="#t_firstclass">first class</a> type. If the function signature
4412 indicates the function accepts a variable number of arguments, the extra
4413 arguments can be specified.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4414 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4415 <li>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]4416 <p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4417 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
4418 '<tt>readnone</tt>' attributes are valid here.</p>
4419 </li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4420</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4421
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4422<h5>Semantics:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4423
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4424<p>The '<tt>call</tt>' instruction is used to cause control flow to
4425transfer to a specified function, with its incoming arguments bound to
4426the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
4427instruction in the called function, control flow continues with the
4428instruction after the function call, and the return value of the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4429function is bound to the result argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4430
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4431<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4432
4433<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4434 %retval = call i32 @test(i32 %argc)
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]4435 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4436 %X = tail call i32 @foo() <i>; yields i32</i>
4437 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4438 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]4439
4440 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4441 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]4442 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
4443 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]4444 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]4445 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4446</pre>
4447
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4448</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4449
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4450<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4451<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]4452 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4453</div>
4454
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4455<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4456
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4457<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4458
4459<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4460 &lt;resultval&gt; = va_arg &lt;va_list*&gt; &lt;arglist&gt;, &lt;argty&gt;
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4461</pre>
4462
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4463<h5>Overview:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4464
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4465<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4466the "variable argument" area of a function call. It is used to implement the
4467<tt>va_arg</tt> macro in C.</p>
4468
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4469<h5>Arguments:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4470
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4471<p>This instruction takes a <tt>va_list*</tt> value and the type of
4472the argument. It returns a value of the specified argument type and
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4473increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4474actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4475
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4476<h5>Semantics:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4477
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4478<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
4479type from the specified <tt>va_list</tt> and causes the
4480<tt>va_list</tt> to point to the next argument. For more information,
4481see the variable argument handling <a href="#int_varargs">Intrinsic
4482Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4483
4484<p>It is legal for this instruction to be called in a function which does not
4485take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4486function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4487
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4488<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4489href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4490argument.</p>
4491
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4492<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4493
4494<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4495
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4496</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4497
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4498<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4499<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4500<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4501
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4502<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4503
4504<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4505well known names and semantics and are required to follow certain restrictions.
4506Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4507language that does not require changing all of the transformations in LLVM when
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]4508adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4509
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4510<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4511prefix is reserved in LLVM for intrinsic names; thus, function names may not
4512begin with this prefix. Intrinsic functions must always be external functions:
4513you cannot define the body of intrinsic functions. Intrinsic functions may
4514only be used in call or invoke instructions: it is illegal to take the address
4515of an intrinsic function. Additionally, because intrinsic functions are part
4516of the LLVM language, it is required if any are added that they be documented
4517here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4518
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4519<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
4520a family of functions that perform the same operation but on different data
4521types. Because LLVM can represent over 8 million different integer types,
4522overloading is used commonly to allow an intrinsic function to operate on any
4523integer type. One or more of the argument types or the result type can be
4524overloaded to accept any integer type. Argument types may also be defined as
4525exactly matching a previous argument's type or the result type. This allows an
4526intrinsic function which accepts multiple arguments, but needs all of them to
4527be of the same type, to only be overloaded with respect to a single argument or
4528the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4529
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4530<p>Overloaded intrinsics will have the names of its overloaded argument types
4531encoded into its function name, each preceded by a period. Only those types
4532which are overloaded result in a name suffix. Arguments whose type is matched
4533against another type do not. For example, the <tt>llvm.ctpop</tt> function can
4534take an integer of any width and returns an integer of exactly the same integer
4535width. This leads to a family of functions such as
4536<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
4537Only one type, the return type, is overloaded, and only one type suffix is
4538required. Because the argument's type is matched against the return type, it
4539does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4540
4541<p>To learn how to add an intrinsic function, please see the
4542<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4543</p>
4544
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4545</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4546
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4547<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4548<div class="doc_subsection">
4549 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
4550</div>
4551
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4552<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4553
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4554<p>Variable argument support is defined in LLVM with the <a
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]4555 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4556intrinsic functions. These functions are related to the similarly
4557named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4558
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4559<p>All of these functions operate on arguments that use a
4560target-specific value type "<tt>va_list</tt>". The LLVM assembly
4561language reference manual does not define what this type is, so all
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4562transformations should be prepared to handle these functions regardless of
4563the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4564
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]4565<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4566instruction and the variable argument handling intrinsic functions are
4567used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4568
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4569<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4570<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4571define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4572 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4573 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4574 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4575 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4576
4577 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4578 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4579
4580 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4581 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4582 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4583 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4584 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4585
4586 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4587 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4588 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4589}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4590
4591declare void @llvm.va_start(i8*)
4592declare void @llvm.va_copy(i8*, i8*)
4593declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4594</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4595</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4596
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4597</div>
4598
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4599<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4600<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4601 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4602</div>
4603
4604
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4605<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4606<h5>Syntax:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4607<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4608<h5>Overview:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4609<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4610<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
4611href="#i_va_arg">va_arg</a></tt>.</p>
4612
4613<h5>Arguments:</h5>
4614
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4615<p>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4616
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4617<h5>Semantics:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4618
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4619<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4620macro available in C. In a target-dependent way, it initializes the
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4621<tt>va_list</tt> element to which the argument points, so that the next call to
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4622<tt>va_arg</tt> will produce the first variable argument passed to the function.
4623Unlike the C <tt>va_start</tt> macro, this intrinsic does not need to know the
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4624last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4625
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4626</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4627
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4628<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4629<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4630 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4631</div>
4632
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4633<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4634<h5>Syntax:</h5>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4635<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4636<h5>Overview:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4637
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4638<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4639which has been initialized previously with <tt><a href="#int_va_start">llvm.va_start</a></tt>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4640or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4641
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4642<h5>Arguments:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4643
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4644<p>The argument is a pointer to a <tt>va_list</tt> to destroy.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4645
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4646<h5>Semantics:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4647
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4648<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4649macro available in C. In a target-dependent way, it destroys the
4650<tt>va_list</tt> element to which the argument points. Calls to <a
4651href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
4652<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
4653<tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4654
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4655</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4656
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4657<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4658<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4659 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4660</div>
4661
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4662<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4663
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4664<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4665
4666<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4667 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4668</pre>
4669
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4670<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4671
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4672<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
4673from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4674
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4675<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4676
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4677<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Andrew Lenharthd0a4c622005-06-22 20:38:11 +0000[diff] [blame]4678The second argument is a pointer to a <tt>va_list</tt> element to copy from.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4679
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4680
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4681<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4682
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4683<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
4684macro available in C. In a target-dependent way, it copies the source
4685<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
4686intrinsic is necessary because the <tt><a href="#int_va_start">
4687llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
4688example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4689
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4690</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4691
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4692<!-- ======================================================================= -->
4693<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4694 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
4695</div>
4696
4697<div class="doc_text">
4698
4699<p>
4700LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]4701Collection</a> (GC) requires the implementation and generation of these
4702intrinsics.
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4703These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4704stack</a>, as well as garbage collector implementations that require <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4705href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4706Front-ends for type-safe garbage collected languages should generate these
4707intrinsics to make use of the LLVM garbage collectors. For more details, see <a
4708href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
4709</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]4710
4711<p>The garbage collection intrinsics only operate on objects in the generic
4712 address space (address space zero).</p>
4713
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4714</div>
4715
4716<!-- _______________________________________________________________________ -->
4717<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4718 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4719</div>
4720
4721<div class="doc_text">
4722
4723<h5>Syntax:</h5>
4724
4725<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4726 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4727</pre>
4728
4729<h5>Overview:</h5>
4730
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]4731<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4732the code generator, and allows some metadata to be associated with it.</p>
4733
4734<h5>Arguments:</h5>
4735
4736<p>The first argument specifies the address of a stack object that contains the
4737root pointer. The second pointer (which must be either a constant or a global
4738value address) contains the meta-data to be associated with the root.</p>
4739
4740<h5>Semantics:</h5>
4741
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]4742<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4743location. At compile-time, the code generator generates information to allow
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4744the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
4745intrinsic may only be used in a function which <a href="#gc">specifies a GC
4746algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4747
4748</div>
4749
4750
4751<!-- _______________________________________________________________________ -->
4752<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4753 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4754</div>
4755
4756<div class="doc_text">
4757
4758<h5>Syntax:</h5>
4759
4760<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4761 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4762</pre>
4763
4764<h5>Overview:</h5>
4765
4766<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4767locations, allowing garbage collector implementations that require read
4768barriers.</p>
4769
4770<h5>Arguments:</h5>
4771
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4772<p>The second argument is the address to read from, which should be an address
4773allocated from the garbage collector. The first object is a pointer to the
4774start of the referenced object, if needed by the language runtime (otherwise
4775null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4776
4777<h5>Semantics:</h5>
4778
4779<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4780instruction, but may be replaced with substantially more complex code by the
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4781garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
4782may only be used in a function which <a href="#gc">specifies a GC
4783algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4784
4785</div>
4786
4787
4788<!-- _______________________________________________________________________ -->
4789<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4790 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4791</div>
4792
4793<div class="doc_text">
4794
4795<h5>Syntax:</h5>
4796
4797<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4798 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4799</pre>
4800
4801<h5>Overview:</h5>
4802
4803<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4804locations, allowing garbage collector implementations that require write
4805barriers (such as generational or reference counting collectors).</p>
4806
4807<h5>Arguments:</h5>
4808
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4809<p>The first argument is the reference to store, the second is the start of the
4810object to store it to, and the third is the address of the field of Obj to
4811store to. If the runtime does not require a pointer to the object, Obj may be
4812null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4813
4814<h5>Semantics:</h5>
4815
4816<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4817instruction, but may be replaced with substantially more complex code by the
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4818garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
4819may only be used in a function which <a href="#gc">specifies a GC
4820algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4821
4822</div>
4823
4824
4825
4826<!-- ======================================================================= -->
4827<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4828 <a name="int_codegen">Code Generator Intrinsics</a>
4829</div>
4830
4831<div class="doc_text">
4832<p>
4833These intrinsics are provided by LLVM to expose special features that may only
4834be implemented with code generator support.
4835</p>
4836
4837</div>
4838
4839<!-- _______________________________________________________________________ -->
4840<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4841 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4842</div>
4843
4844<div class="doc_text">
4845
4846<h5>Syntax:</h5>
4847<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4848 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4849</pre>
4850
4851<h5>Overview:</h5>
4852
4853<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4854The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4855target-specific value indicating the return address of the current function
4856or one of its callers.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4857</p>
4858
4859<h5>Arguments:</h5>
4860
4861<p>
4862The argument to this intrinsic indicates which function to return the address
4863for. Zero indicates the calling function, one indicates its caller, etc. The
4864argument is <b>required</b> to be a constant integer value.
4865</p>
4866
4867<h5>Semantics:</h5>
4868
4869<p>
4870The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4871the return address of the specified call frame, or zero if it cannot be
4872identified. The value returned by this intrinsic is likely to be incorrect or 0
4873for arguments other than zero, so it should only be used for debugging purposes.
4874</p>
4875
4876<p>
4877Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4878aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4879source-language caller.
4880</p>
4881</div>
4882
4883
4884<!-- _______________________________________________________________________ -->
4885<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4886 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4887</div>
4888
4889<div class="doc_text">
4890
4891<h5>Syntax:</h5>
4892<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4893 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4894</pre>
4895
4896<h5>Overview:</h5>
4897
4898<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4899The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
4900target-specific frame pointer value for the specified stack frame.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4901</p>
4902
4903<h5>Arguments:</h5>
4904
4905<p>
4906The argument to this intrinsic indicates which function to return the frame
4907pointer for. Zero indicates the calling function, one indicates its caller,
4908etc. The argument is <b>required</b> to be a constant integer value.
4909</p>
4910
4911<h5>Semantics:</h5>
4912
4913<p>
4914The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
4915the frame address of the specified call frame, or zero if it cannot be
4916identified. The value returned by this intrinsic is likely to be incorrect or 0
4917for arguments other than zero, so it should only be used for debugging purposes.
4918</p>
4919
4920<p>
4921Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4922aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4923source-language caller.
4924</p>
4925</div>
4926
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4927<!-- _______________________________________________________________________ -->
4928<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4929 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4930</div>
4931
4932<div class="doc_text">
4933
4934<h5>Syntax:</h5>
4935<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4936 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4937</pre>
4938
4939<h5>Overview:</h5>
4940
4941<p>
4942The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4943the function stack, for use with <a href="#int_stackrestore">
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4944<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
4945features like scoped automatic variable sized arrays in C99.
4946</p>
4947
4948<h5>Semantics:</h5>
4949
4950<p>
4951This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4952href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4953<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
4954<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
4955state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
4956practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
4957that were allocated after the <tt>llvm.stacksave</tt> was executed.
4958</p>
4959
4960</div>
4961
4962<!-- _______________________________________________________________________ -->
4963<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4964 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4965</div>
4966
4967<div class="doc_text">
4968
4969<h5>Syntax:</h5>
4970<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4971 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4972</pre>
4973
4974<h5>Overview:</h5>
4975
4976<p>
4977The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
4978the function stack to the state it was in when the corresponding <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4979href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4980useful for implementing language features like scoped automatic variable sized
4981arrays in C99.
4982</p>
4983
4984<h5>Semantics:</h5>
4985
4986<p>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4987See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4988</p>
4989
4990</div>
4991
4992
4993<!-- _______________________________________________________________________ -->
4994<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4995 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4996</div>
4997
4998<div class="doc_text">
4999
5000<h5>Syntax:</h5>
5001<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5002 declare void @llvm.prefetch(i8* &lt;address&gt;, i32 &lt;rw&gt;, i32 &lt;locality&gt;)
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5003</pre>
5004
5005<h5>Overview:</h5>
5006
5007
5008<p>
5009The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5010a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
5011no
5012effect on the behavior of the program but can change its performance
Chris Lattner2a615362005-02-28 19:47:14 +0000[diff] [blame]5013characteristics.
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5014</p>
5015
5016<h5>Arguments:</h5>
5017
5018<p>
5019<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
5020determining if the fetch should be for a read (0) or write (1), and
5021<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattneraeffb4a2005-03-07 20:31:38 +0000[diff] [blame]5022locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5023<tt>locality</tt> arguments must be constant integers.
5024</p>
5025
5026<h5>Semantics:</h5>
5027
5028<p>
5029This intrinsic does not modify the behavior of the program. In particular,
5030prefetches cannot trap and do not produce a value. On targets that support this
5031intrinsic, the prefetch can provide hints to the processor cache for better
5032performance.
5033</p>
5034
5035</div>
5036
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5037<!-- _______________________________________________________________________ -->
5038<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5039 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5040</div>
5041
5042<div class="doc_text">
5043
5044<h5>Syntax:</h5>
5045<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5046 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5047</pre>
5048
5049<h5>Overview:</h5>
5050
5051
5052<p>
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5053The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5054(PC) in a region of
5055code to simulators and other tools. The method is target specific, but it is
5056expected that the marker will use exported symbols to transmit the PC of the
5057marker.
5058The marker makes no guarantees that it will remain with any specific instruction
5059after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb3e7afd2006-03-24 07:16:10 +0000[diff] [blame]5060optimizations. The intended use is to be inserted after optimizations to allow
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5061correlations of simulation runs.
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5062</p>
5063
5064<h5>Arguments:</h5>
5065
5066<p>
5067<tt>id</tt> is a numerical id identifying the marker.
5068</p>
5069
5070<h5>Semantics:</h5>
5071
5072<p>
5073This intrinsic does not modify the behavior of the program. Backends that do not
5074support this intrinisic may ignore it.
5075</p>
5076
5077</div>
5078
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5079<!-- _______________________________________________________________________ -->
5080<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5081 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5082</div>
5083
5084<div class="doc_text">
5085
5086<h5>Syntax:</h5>
5087<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5088 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5089</pre>
5090
5091<h5>Overview:</h5>
5092
5093
5094<p>
5095The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5096counter register (or similar low latency, high accuracy clocks) on those targets
5097that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
5098As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
5099should only be used for small timings.
5100</p>
5101
5102<h5>Semantics:</h5>
5103
5104<p>
5105When directly supported, reading the cycle counter should not modify any memory.
5106Implementations are allowed to either return a application specific value or a
5107system wide value. On backends without support, this is lowered to a constant 0.
5108</p>
5109
5110</div>
5111
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5112<!-- ======================================================================= -->
5113<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5114 <a name="int_libc">Standard C Library Intrinsics</a>
5115</div>
5116
5117<div class="doc_text">
5118<p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5119LLVM provides intrinsics for a few important standard C library functions.
5120These intrinsics allow source-language front-ends to pass information about the
5121alignment of the pointer arguments to the code generator, providing opportunity
5122for more efficient code generation.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5123</p>
5124
5125</div>
5126
5127<!-- _______________________________________________________________________ -->
5128<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5129 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5130</div>
5131
5132<div class="doc_text">
5133
5134<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5135<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
5136width. Not all targets support all bit widths however.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5137<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5138 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5139 i8 &lt;len&gt;, i32 &lt;align&gt;)
5140 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5141 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5142 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5143 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5144 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5145 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5146</pre>
5147
5148<h5>Overview:</h5>
5149
5150<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5151The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5152location to the destination location.
5153</p>
5154
5155<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5156Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5157intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5158</p>
5159
5160<h5>Arguments:</h5>
5161
5162<p>
5163The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5164the source. The third argument is an integer argument
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5165specifying the number of bytes to copy, and the fourth argument is the alignment
5166of the source and destination locations.
5167</p>
5168
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5169<p>
5170If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattnerf0afc2c2006-03-04 00:02:10 +0000[diff] [blame]5171the caller guarantees that both the source and destination pointers are aligned
5172to that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5173</p>
5174
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5175<h5>Semantics:</h5>
5176
5177<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5178The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5179location to the destination location, which are not allowed to overlap. It
5180copies "len" bytes of memory over. If the argument is known to be aligned to
5181some boundary, this can be specified as the fourth argument, otherwise it should
5182be set to 0 or 1.
5183</p>
5184</div>
5185
5186
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5187<!-- _______________________________________________________________________ -->
5188<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5189 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5190</div>
5191
5192<div class="doc_text">
5193
5194<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5195<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
5196width. Not all targets support all bit widths however.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5197<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5198 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5199 i8 &lt;len&gt;, i32 &lt;align&gt;)
5200 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5201 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5202 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5203 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5204 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5205 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5206</pre>
5207
5208<h5>Overview:</h5>
5209
5210<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5211The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
5212location to the destination location. It is similar to the
Chris Lattner4b2cbcf2008-01-06 19:51:52 +0000[diff] [blame]5213'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5214</p>
5215
5216<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5217Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5218intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5219</p>
5220
5221<h5>Arguments:</h5>
5222
5223<p>
5224The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5225the source. The third argument is an integer argument
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5226specifying the number of bytes to copy, and the fourth argument is the alignment
5227of the source and destination locations.
5228</p>
5229
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5230<p>
5231If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattnerf0afc2c2006-03-04 00:02:10 +0000[diff] [blame]5232the caller guarantees that the source and destination pointers are aligned to
5233that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5234</p>
5235
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5236<h5>Semantics:</h5>
5237
5238<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5239The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5240location to the destination location, which may overlap. It
5241copies "len" bytes of memory over. If the argument is known to be aligned to
5242some boundary, this can be specified as the fourth argument, otherwise it should
5243be set to 0 or 1.
5244</p>
5245</div>
5246
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5247
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5248<!-- _______________________________________________________________________ -->
5249<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5250 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5251</div>
5252
5253<div class="doc_text">
5254
5255<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5256<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
5257width. Not all targets support all bit widths however.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5258<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5259 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5260 i8 &lt;len&gt;, i32 &lt;align&gt;)
5261 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5262 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5263 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5264 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5265 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5266 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5267</pre>
5268
5269<h5>Overview:</h5>
5270
5271<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5272The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5273byte value.
5274</p>
5275
5276<p>
5277Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
5278does not return a value, and takes an extra alignment argument.
5279</p>
5280
5281<h5>Arguments:</h5>
5282
5283<p>
5284The first argument is a pointer to the destination to fill, the second is the
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5285byte value to fill it with, the third argument is an integer
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5286argument specifying the number of bytes to fill, and the fourth argument is the
5287known alignment of destination location.
5288</p>
5289
5290<p>
5291If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattnerf0afc2c2006-03-04 00:02:10 +0000[diff] [blame]5292the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5293</p>
5294
5295<h5>Semantics:</h5>
5296
5297<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5298The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
5299the
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5300destination location. If the argument is known to be aligned to some boundary,
5301this can be specified as the fourth argument, otherwise it should be set to 0 or
53021.
5303</p>
5304</div>
5305
5306
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5307<!-- _______________________________________________________________________ -->
5308<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5309 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5310</div>
5311
5312<div class="doc_text">
5313
5314<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5315<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5316floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5317types however.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5318<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5319 declare float @llvm.sqrt.f32(float %Val)
5320 declare double @llvm.sqrt.f64(double %Val)
5321 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5322 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5323 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5324</pre>
5325
5326<h5>Overview:</h5>
5327
5328<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5329The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5330returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5331<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner103e2d72008-01-29 07:00:44 +0000[diff] [blame]5332negative numbers other than -0.0 (which allows for better optimization, because
5333there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
5334defined to return -0.0 like IEEE sqrt.
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5335</p>
5336
5337<h5>Arguments:</h5>
5338
5339<p>
5340The argument and return value are floating point numbers of the same type.
5341</p>
5342
5343<h5>Semantics:</h5>
5344
5345<p>
Dan Gohmand6257fe2007-07-16 14:37:41 +0000[diff] [blame]5346This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5347floating point number.
5348</p>
5349</div>
5350
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5351<!-- _______________________________________________________________________ -->
5352<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5353 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5354</div>
5355
5356<div class="doc_text">
5357
5358<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5359<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5360floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5361types however.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5362<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5363 declare float @llvm.powi.f32(float %Val, i32 %power)
5364 declare double @llvm.powi.f64(double %Val, i32 %power)
5365 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5366 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5367 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5368</pre>
5369
5370<h5>Overview:</h5>
5371
5372<p>
5373The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5374specified (positive or negative) power. The order of evaluation of
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5375multiplications is not defined. When a vector of floating point type is
5376used, the second argument remains a scalar integer value.
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5377</p>
5378
5379<h5>Arguments:</h5>
5380
5381<p>
5382The second argument is an integer power, and the first is a value to raise to
5383that power.
5384</p>
5385
5386<h5>Semantics:</h5>
5387
5388<p>
5389This function returns the first value raised to the second power with an
5390unspecified sequence of rounding operations.</p>
5391</div>
5392
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5393<!-- _______________________________________________________________________ -->
5394<div class="doc_subsubsection">
5395 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5396</div>
5397
5398<div class="doc_text">
5399
5400<h5>Syntax:</h5>
5401<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5402floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5403types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5404<pre>
5405 declare float @llvm.sin.f32(float %Val)
5406 declare double @llvm.sin.f64(double %Val)
5407 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5408 declare fp128 @llvm.sin.f128(fp128 %Val)
5409 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5410</pre>
5411
5412<h5>Overview:</h5>
5413
5414<p>
5415The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
5416</p>
5417
5418<h5>Arguments:</h5>
5419
5420<p>
5421The argument and return value are floating point numbers of the same type.
5422</p>
5423
5424<h5>Semantics:</h5>
5425
5426<p>
5427This function returns the sine of the specified operand, returning the
5428same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5429conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5430</div>
5431
5432<!-- _______________________________________________________________________ -->
5433<div class="doc_subsubsection">
5434 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5435</div>
5436
5437<div class="doc_text">
5438
5439<h5>Syntax:</h5>
5440<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5441floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5442types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5443<pre>
5444 declare float @llvm.cos.f32(float %Val)
5445 declare double @llvm.cos.f64(double %Val)
5446 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5447 declare fp128 @llvm.cos.f128(fp128 %Val)
5448 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5449</pre>
5450
5451<h5>Overview:</h5>
5452
5453<p>
5454The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
5455</p>
5456
5457<h5>Arguments:</h5>
5458
5459<p>
5460The argument and return value are floating point numbers of the same type.
5461</p>
5462
5463<h5>Semantics:</h5>
5464
5465<p>
5466This function returns the cosine of the specified operand, returning the
5467same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5468conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5469</div>
5470
5471<!-- _______________________________________________________________________ -->
5472<div class="doc_subsubsection">
5473 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5474</div>
5475
5476<div class="doc_text">
5477
5478<h5>Syntax:</h5>
5479<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5480floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5481types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5482<pre>
5483 declare float @llvm.pow.f32(float %Val, float %Power)
5484 declare double @llvm.pow.f64(double %Val, double %Power)
5485 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5486 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5487 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5488</pre>
5489
5490<h5>Overview:</h5>
5491
5492<p>
5493The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5494specified (positive or negative) power.
5495</p>
5496
5497<h5>Arguments:</h5>
5498
5499<p>
5500The second argument is a floating point power, and the first is a value to
5501raise to that power.
5502</p>
5503
5504<h5>Semantics:</h5>
5505
5506<p>
5507This function returns the first value raised to the second power,
5508returning the
5509same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5510conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5511</div>
5512
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5513
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5514<!-- ======================================================================= -->
5515<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5516 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5517</div>
5518
5519<div class="doc_text">
5520<p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5521LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5522These allow efficient code generation for some algorithms.
5523</p>
5524
5525</div>
5526
5527<!-- _______________________________________________________________________ -->
5528<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5529 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5530</div>
5531
5532<div class="doc_text">
5533
5534<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5535<p>This is an overloaded intrinsic function. You can use bswap on any integer
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5536type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5537<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5538 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5539 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5540 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5541</pre>
5542
5543<h5>Overview:</h5>
5544
5545<p>
Reid Spencer338ea092007-04-02 02:25:19 +0000[diff] [blame]5546The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5547values with an even number of bytes (positive multiple of 16 bits). These are
5548useful for performing operations on data that is not in the target's native
5549byte order.
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5550</p>
5551
5552<h5>Semantics:</h5>
5553
5554<p>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5555The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5556and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
5557intrinsic returns an i32 value that has the four bytes of the input i32
5558swapped, so that if the input bytes are numbered 0, 1, 2, 3 then the returned
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5559i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
5560<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5561additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5562</p>
5563
5564</div>
5565
5566<!-- _______________________________________________________________________ -->
5567<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5568 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5569</div>
5570
5571<div class="doc_text">
5572
5573<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5574<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5575width. Not all targets support all bit widths however.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5576<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5577 declare i8 @llvm.ctpop.i8 (i8 &lt;src&gt;)
5578 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5579 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5580 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5581 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5582</pre>
5583
5584<h5>Overview:</h5>
5585
5586<p>
Chris Lattnerec6cb612006-01-16 22:38:59 +0000[diff] [blame]5587The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
5588value.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5589</p>
5590
5591<h5>Arguments:</h5>
5592
5593<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]5594The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5595integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5596</p>
5597
5598<h5>Semantics:</h5>
5599
5600<p>
5601The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
5602</p>
5603</div>
5604
5605<!-- _______________________________________________________________________ -->
5606<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5607 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5608</div>
5609
5610<div class="doc_text">
5611
5612<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5613<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5614integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5615<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5616 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5617 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5618 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5619 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5620 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5621</pre>
5622
5623<h5>Overview:</h5>
5624
5625<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5626The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5627leading zeros in a variable.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5628</p>
5629
5630<h5>Arguments:</h5>
5631
5632<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]5633The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5634integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5635</p>
5636
5637<h5>Semantics:</h5>
5638
5639<p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5640The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
5641in a variable. If the src == 0 then the result is the size in bits of the type
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5642of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5643</p>
5644</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5645
5646
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5647
5648<!-- _______________________________________________________________________ -->
5649<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5650 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5651</div>
5652
5653<div class="doc_text">
5654
5655<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5656<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5657integer bit width. Not all targets support all bit widths however.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5658<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5659 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5660 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5661 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5662 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5663 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5664</pre>
5665
5666<h5>Overview:</h5>
5667
5668<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5669The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5670trailing zeros.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5671</p>
5672
5673<h5>Arguments:</h5>
5674
5675<p>
5676The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5677integer type. The return type must match the argument type.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5678</p>
5679
5680<h5>Semantics:</h5>
5681
5682<p>
5683The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
5684in a variable. If the src == 0 then the result is the size in bits of the type
5685of src. For example, <tt>llvm.cttz(2) = 1</tt>.
5686</p>
5687</div>
5688
Reid Spencer497d93e2007-04-01 08:27:01 +0000[diff] [blame]5689<!-- _______________________________________________________________________ -->
5690<div class="doc_subsubsection">
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5691 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5692</div>
5693
5694<div class="doc_text">
5695
5696<h5>Syntax:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5697<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5698on any integer bit width.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5699<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5700 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
5701 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5702</pre>
5703
5704<h5>Overview:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5705<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5706range of bits from an integer value and returns them in the same bit width as
5707the original value.</p>
5708
5709<h5>Arguments:</h5>
5710<p>The first argument, <tt>%val</tt> and the result may be integer types of
5711any bit width but they must have the same bit width. The second and third
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5712arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5713
5714<h5>Semantics:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5715<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5716of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
5717<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
5718operates in forward mode.</p>
5719<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
5720right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5721only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
5722<ol>
5723 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
5724 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
5725 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
5726 to determine the number of bits to retain.</li>
5727 <li>A mask of the retained bits is created by shifting a -1 value.</li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5728 <li>The mask is ANDed with <tt>%val</tt> to produce the result.</li>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5729</ol>
Reid Spencerd6a85b52007-05-14 16:14:57 +0000[diff] [blame]5730<p>In reverse mode, a similar computation is made except that the bits are
5731returned in the reverse order. So, for example, if <tt>X</tt> has the value
5732<tt>i16 0x0ACF (101011001111)</tt> and we apply
5733<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
5734<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5735</div>
5736
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5737<div class="doc_subsubsection">
5738 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
5739</div>
5740
5741<div class="doc_text">
5742
5743<h5>Syntax:</h5>
5744<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5745on any integer bit width.</p>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5746<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5747 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
5748 declare i29 @llvm.part.set.i29.i9 (i29 %val, i9 %repl, i32 %lo, i32 %hi)
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5749</pre>
5750
5751<h5>Overview:</h5>
5752<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
5753of bits in an integer value with another integer value. It returns the integer
5754with the replaced bits.</p>
5755
5756<h5>Arguments:</h5>
5757<p>The first argument, <tt>%val</tt> and the result may be integer types of
5758any bit width but they must have the same bit width. <tt>%val</tt> is the value
5759whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
5760integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
5761type since they specify only a bit index.</p>
5762
5763<h5>Semantics:</h5>
5764<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
5765of operation: forwards and reverse. If <tt>%lo</tt> is greater than
5766<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
5767operates in forward mode.</p>
5768<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
5769truncating it down to the size of the replacement area or zero extending it
5770up to that size.</p>
5771<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5772are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5773in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5774to the <tt>%hi</tt>th bit.</p>
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5775<p>In reverse mode, a similar computation is made except that the bits are
5776reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5777<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.</p>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5778<h5>Examples:</h5>
5779<pre>
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5780 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5781 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5782 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5783 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5784 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]5785</pre>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5786</div>
5787
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5788<!-- ======================================================================= -->
5789<div class="doc_subsection">
5790 <a name="int_debugger">Debugger Intrinsics</a>
5791</div>
5792
5793<div class="doc_text">
5794<p>
5795The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
5796are described in the <a
5797href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
5798Debugging</a> document.
5799</p>
5800</div>
5801
5802
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]5803<!-- ======================================================================= -->
5804<div class="doc_subsection">
5805 <a name="int_eh">Exception Handling Intrinsics</a>
5806</div>
5807
5808<div class="doc_text">
5809<p> The LLVM exception handling intrinsics (which all start with
5810<tt>llvm.eh.</tt> prefix), are described in the <a
5811href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
5812Handling</a> document. </p>
5813</div>
5814
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5815<!-- ======================================================================= -->
5816<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5817 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5818</div>
5819
5820<div class="doc_text">
5821<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5822 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5823 the <tt>nest</tt> attribute, from a function. The result is a callable
5824 function pointer lacking the nest parameter - the caller does not need
5825 to provide a value for it. Instead, the value to use is stored in
5826 advance in a "trampoline", a block of memory usually allocated
5827 on the stack, which also contains code to splice the nest value into the
5828 argument list. This is used to implement the GCC nested function address
5829 extension.
5830</p>
5831<p>
5832 For example, if the function is
5833 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
Bill Wendling03295ca2007-09-22 09:23:55 +0000[diff] [blame]5834 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as follows:</p>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5835<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5836 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
5837 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
5838 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
5839 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5840</pre>
Bill Wendling03295ca2007-09-22 09:23:55 +0000[diff] [blame]5841 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
5842 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5843</div>
5844
5845<!-- _______________________________________________________________________ -->
5846<div class="doc_subsubsection">
5847 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
5848</div>
5849<div class="doc_text">
5850<h5>Syntax:</h5>
5851<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5852declare i8* @llvm.init.trampoline(i8* &lt;tramp&gt;, i8* &lt;func&gt;, i8* &lt;nval&gt;)
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5853</pre>
5854<h5>Overview:</h5>
5855<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5856 This fills the memory pointed to by <tt>tramp</tt> with code
5857 and returns a function pointer suitable for executing it.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5858</p>
5859<h5>Arguments:</h5>
5860<p>
5861 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
5862 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
5863 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsc00c2ba2007-08-22 23:39:54 +0000[diff] [blame]5864 intrinsic. Note that the size and the alignment are target-specific - LLVM
5865 currently provides no portable way of determining them, so a front-end that
5866 generates this intrinsic needs to have some target-specific knowledge.
5867 The <tt>func</tt> argument must hold a function bitcast to an <tt>i8*</tt>.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5868</p>
5869<h5>Semantics:</h5>
5870<p>
5871 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5872 dependent code, turning it into a function. A pointer to this function is
5873 returned, but needs to be bitcast to an
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5874 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5875 before being called. The new function's signature is the same as that of
5876 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
5877 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
5878 of pointer type. Calling the new function is equivalent to calling
5879 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
5880 missing <tt>nest</tt> argument. If, after calling
5881 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
5882 modified, then the effect of any later call to the returned function pointer is
5883 undefined.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5884</p>
5885</div>
5886
5887<!-- ======================================================================= -->
5888<div class="doc_subsection">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]5889 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
5890</div>
5891
5892<div class="doc_text">
5893<p>
5894 These intrinsic functions expand the "universal IR" of LLVM to represent
5895 hardware constructs for atomic operations and memory synchronization. This
5896 provides an interface to the hardware, not an interface to the programmer. It
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5897 is aimed at a low enough level to allow any programming models or APIs
5898 (Application Programming Interfaces) which
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]5899 need atomic behaviors to map cleanly onto it. It is also modeled primarily on
5900 hardware behavior. Just as hardware provides a "universal IR" for source
5901 languages, it also provides a starting point for developing a "universal"
5902 atomic operation and synchronization IR.
5903</p>
5904<p>
5905 These do <em>not</em> form an API such as high-level threading libraries,
5906 software transaction memory systems, atomic primitives, and intrinsic
5907 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
5908 application libraries. The hardware interface provided by LLVM should allow
5909 a clean implementation of all of these APIs and parallel programming models.
5910 No one model or paradigm should be selected above others unless the hardware
5911 itself ubiquitously does so.
5912
5913</p>
5914</div>
5915
5916<!-- _______________________________________________________________________ -->
5917<div class="doc_subsubsection">
5918 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
5919</div>
5920<div class="doc_text">
5921<h5>Syntax:</h5>
5922<pre>
5923declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;,
5924i1 &lt;device&gt; )
5925
5926</pre>
5927<h5>Overview:</h5>
5928<p>
5929 The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
5930 specific pairs of memory access types.
5931</p>
5932<h5>Arguments:</h5>
5933<p>
5934 The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
5935 The first four arguments enables a specific barrier as listed below. The fith
5936 argument specifies that the barrier applies to io or device or uncached memory.
5937
5938</p>
5939 <ul>
5940 <li><tt>ll</tt>: load-load barrier</li>
5941 <li><tt>ls</tt>: load-store barrier</li>
5942 <li><tt>sl</tt>: store-load barrier</li>
5943 <li><tt>ss</tt>: store-store barrier</li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5944 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]5945 </ul>
5946<h5>Semantics:</h5>
5947<p>
5948 This intrinsic causes the system to enforce some ordering constraints upon
5949 the loads and stores of the program. This barrier does not indicate
5950 <em>when</em> any events will occur, it only enforces an <em>order</em> in
5951 which they occur. For any of the specified pairs of load and store operations
5952 (f.ex. load-load, or store-load), all of the first operations preceding the
5953 barrier will complete before any of the second operations succeeding the
5954 barrier begin. Specifically the semantics for each pairing is as follows:
5955</p>
5956 <ul>
5957 <li><tt>ll</tt>: All loads before the barrier must complete before any load
5958 after the barrier begins.</li>
5959
5960 <li><tt>ls</tt>: All loads before the barrier must complete before any
5961 store after the barrier begins.</li>
5962 <li><tt>ss</tt>: All stores before the barrier must complete before any
5963 store after the barrier begins.</li>
5964 <li><tt>sl</tt>: All stores before the barrier must complete before any
5965 load after the barrier begins.</li>
5966 </ul>
5967<p>
5968 These semantics are applied with a logical "and" behavior when more than one
5969 is enabled in a single memory barrier intrinsic.
5970</p>
5971<p>
5972 Backends may implement stronger barriers than those requested when they do not
5973 support as fine grained a barrier as requested. Some architectures do not
5974 need all types of barriers and on such architectures, these become noops.
5975</p>
5976<h5>Example:</h5>
5977<pre>
5978%ptr = malloc i32
5979 store i32 4, %ptr
5980
5981%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
5982 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
5983 <i>; guarantee the above finishes</i>
5984 store i32 8, %ptr <i>; before this begins</i>
5985</pre>
5986</div>
5987
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5988<!-- _______________________________________________________________________ -->
5989<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]5990 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5991</div>
5992<div class="doc_text">
5993<h5>Syntax:</h5>
5994<p>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]5995 This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
5996 any integer bit width and for different address spaces. Not all targets
5997 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]5998
5999<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6000declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6001declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6002declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
6003declare i64 @llvm.atomic.cmp.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;cmp&gt;, i64 &lt;val&gt; )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6004
6005</pre>
6006<h5>Overview:</h5>
6007<p>
6008 This loads a value in memory and compares it to a given value. If they are
6009 equal, it stores a new value into the memory.
6010</p>
6011<h5>Arguments:</h5>
6012<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6013 The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6014 well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
6015 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
6016 this integer type. While any bit width integer may be used, targets may only
6017 lower representations they support in hardware.
6018
6019</p>
6020<h5>Semantics:</h5>
6021<p>
6022 This entire intrinsic must be executed atomically. It first loads the value
6023 in memory pointed to by <tt>ptr</tt> and compares it with the value
6024 <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
6025 loaded value is yielded in all cases. This provides the equivalent of an
6026 atomic compare-and-swap operation within the SSA framework.
6027</p>
6028<h5>Examples:</h5>
6029
6030<pre>
6031%ptr = malloc i32
6032 store i32 4, %ptr
6033
6034%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6035%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6036 <i>; yields {i32}:result1 = 4</i>
6037%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6038%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6039
6040%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6041%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6042 <i>; yields {i32}:result2 = 8</i>
6043%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6044
6045%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6046</pre>
6047</div>
6048
6049<!-- _______________________________________________________________________ -->
6050<div class="doc_subsubsection">
6051 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6052</div>
6053<div class="doc_text">
6054<h5>Syntax:</h5>
6055
6056<p>
6057 This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6058 integer bit width. Not all targets support all bit widths however.</p>
6059<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6060declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6061declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6062declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6063declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6064
6065</pre>
6066<h5>Overview:</h5>
6067<p>
6068 This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6069 the value from memory. It then stores the value in <tt>val</tt> in the memory
6070 at <tt>ptr</tt>.
6071</p>
6072<h5>Arguments:</h5>
6073
6074<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6075 The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6076 <tt>val</tt> argument and the result must be integers of the same bit width.
6077 The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6078 integer type. The targets may only lower integer representations they
6079 support.
6080</p>
6081<h5>Semantics:</h5>
6082<p>
6083 This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6084 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6085 equivalent of an atomic swap operation within the SSA framework.
6086
6087</p>
6088<h5>Examples:</h5>
6089<pre>
6090%ptr = malloc i32
6091 store i32 4, %ptr
6092
6093%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6094%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6095 <i>; yields {i32}:result1 = 4</i>
6096%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6097%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6098
6099%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6100%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6101 <i>; yields {i32}:result2 = 8</i>
6102
6103%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6104%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6105</pre>
6106</div>
6107
6108<!-- _______________________________________________________________________ -->
6109<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6110 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6111
6112</div>
6113<div class="doc_text">
6114<h5>Syntax:</h5>
6115<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6116 This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on any
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6117 integer bit width. Not all targets support all bit widths however.</p>
6118<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6119declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6120declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6121declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6122declare i64 @llvm.atomic.load.add.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6123
6124</pre>
6125<h5>Overview:</h5>
6126<p>
6127 This intrinsic adds <tt>delta</tt> to the value stored in memory at
6128 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6129</p>
6130<h5>Arguments:</h5>
6131<p>
6132
6133 The intrinsic takes two arguments, the first a pointer to an integer value
6134 and the second an integer value. The result is also an integer value. These
6135 integer types can have any bit width, but they must all have the same bit
6136 width. The targets may only lower integer representations they support.
6137</p>
6138<h5>Semantics:</h5>
6139<p>
6140 This intrinsic does a series of operations atomically. It first loads the
6141 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6142 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6143</p>
6144
6145<h5>Examples:</h5>
6146<pre>
6147%ptr = malloc i32
6148 store i32 4, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6149%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6150 <i>; yields {i32}:result1 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6151%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6152 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6153%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6154 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6155%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6156</pre>
6157</div>
6158
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6159<!-- _______________________________________________________________________ -->
6160<div class="doc_subsubsection">
6161 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6162
6163</div>
6164<div class="doc_text">
6165<h5>Syntax:</h5>
6166<p>
6167 This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6168 any integer bit width and for different address spaces. Not all targets
6169 support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6170<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6171declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6172declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6173declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6174declare i64 @llvm.atomic.load.sub.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6175
6176</pre>
6177<h5>Overview:</h5>
6178<p>
6179 This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6180 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6181</p>
6182<h5>Arguments:</h5>
6183<p>
6184
6185 The intrinsic takes two arguments, the first a pointer to an integer value
6186 and the second an integer value. The result is also an integer value. These
6187 integer types can have any bit width, but they must all have the same bit
6188 width. The targets may only lower integer representations they support.
6189</p>
6190<h5>Semantics:</h5>
6191<p>
6192 This intrinsic does a series of operations atomically. It first loads the
6193 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6194 result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6195</p>
6196
6197<h5>Examples:</h5>
6198<pre>
6199%ptr = malloc i32
6200 store i32 8, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6201%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6202 <i>; yields {i32}:result1 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6203%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6204 <i>; yields {i32}:result2 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6205%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6206 <i>; yields {i32}:result3 = 2</i>
6207%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6208</pre>
6209</div>
6210
6211<!-- _______________________________________________________________________ -->
6212<div class="doc_subsubsection">
6213 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6214 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6215 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6216 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
6217
6218</div>
6219<div class="doc_text">
6220<h5>Syntax:</h5>
6221<p>
6222 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
6223 <tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6224 <tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
6225 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6226<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6227declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6228declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6229declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6230declare i64 @llvm.atomic.load.and.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6231
6232</pre>
6233
6234<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6235declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6236declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6237declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6238declare i64 @llvm.atomic.load.or.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6239
6240</pre>
6241
6242<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6243declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6244declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6245declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6246declare i64 @llvm.atomic.load.nand.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6247
6248</pre>
6249
6250<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6251declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6252declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6253declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6254declare i64 @llvm.atomic.load.xor.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6255
6256</pre>
6257<h5>Overview:</h5>
6258<p>
6259 These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6260 the value stored in memory at <tt>ptr</tt>. It yields the original value
6261 at <tt>ptr</tt>.
6262</p>
6263<h5>Arguments:</h5>
6264<p>
6265
6266 These intrinsics take two arguments, the first a pointer to an integer value
6267 and the second an integer value. The result is also an integer value. These
6268 integer types can have any bit width, but they must all have the same bit
6269 width. The targets may only lower integer representations they support.
6270</p>
6271<h5>Semantics:</h5>
6272<p>
6273 These intrinsics does a series of operations atomically. They first load the
6274 value stored at <tt>ptr</tt>. They then do the bitwise operation
6275 <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
6276 value stored at <tt>ptr</tt>.
6277</p>
6278
6279<h5>Examples:</h5>
6280<pre>
6281%ptr = malloc i32
6282 store i32 0x0F0F, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6283%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6284 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6285%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6286 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6287%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6288 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6289%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6290 <i>; yields {i32}:result3 = FF</i>
6291%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6292</pre>
6293</div>
6294
6295
6296<!-- _______________________________________________________________________ -->
6297<div class="doc_subsubsection">
6298 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6299 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6300 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6301 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
6302
6303</div>
6304<div class="doc_text">
6305<h5>Syntax:</h5>
6306<p>
6307 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6308 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6309 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6310 address spaces. Not all targets
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6311 support all bit widths however.</p>
6312<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6313declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6314declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6315declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6316declare i64 @llvm.atomic.load.max.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6317
6318</pre>
6319
6320<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6321declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6322declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6323declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6324declare i64 @llvm.atomic.load.min.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6325
6326</pre>
6327
6328<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6329declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6330declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6331declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6332declare i64 @llvm.atomic.load.umax.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6333
6334</pre>
6335
6336<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6337declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6338declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6339declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6340declare i64 @llvm.atomic.load.umin.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6341
6342</pre>
6343<h5>Overview:</h5>
6344<p>
6345 These intrinsics takes the signed or unsigned minimum or maximum of
6346 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6347 original value at <tt>ptr</tt>.
6348</p>
6349<h5>Arguments:</h5>
6350<p>
6351
6352 These intrinsics take two arguments, the first a pointer to an integer value
6353 and the second an integer value. The result is also an integer value. These
6354 integer types can have any bit width, but they must all have the same bit
6355 width. The targets may only lower integer representations they support.
6356</p>
6357<h5>Semantics:</h5>
6358<p>
6359 These intrinsics does a series of operations atomically. They first load the
6360 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
6361 <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
6362 the original value stored at <tt>ptr</tt>.
6363</p>
6364
6365<h5>Examples:</h5>
6366<pre>
6367%ptr = malloc i32
6368 store i32 7, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6369%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6370 <i>; yields {i32}:result0 = 7</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6371%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6372 <i>; yields {i32}:result1 = -2</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6373%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6374 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6375%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6376 <i>; yields {i32}:result3 = 8</i>
6377%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6378</pre>
6379</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6380
6381<!-- ======================================================================= -->
6382<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6383 <a name="int_general">General Intrinsics</a>
6384</div>
6385
6386<div class="doc_text">
6387<p> This class of intrinsics is designed to be generic and has
6388no specific purpose. </p>
6389</div>
6390
6391<!-- _______________________________________________________________________ -->
6392<div class="doc_subsubsection">
6393 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6394</div>
6395
6396<div class="doc_text">
6397
6398<h5>Syntax:</h5>
6399<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]6400 declare void @llvm.var.annotation(i8* &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6401</pre>
6402
6403<h5>Overview:</h5>
6404
6405<p>
6406The '<tt>llvm.var.annotation</tt>' intrinsic
6407</p>
6408
6409<h5>Arguments:</h5>
6410
6411<p>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]6412The first argument is a pointer to a value, the second is a pointer to a
6413global string, the third is a pointer to a global string which is the source
6414file name, and the last argument is the line number.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6415</p>
6416
6417<h5>Semantics:</h5>
6418
6419<p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6420This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6421This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6422annotations. These have no other defined use, they are ignored by code
6423generation and optimization.
6424</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6425</div>
6426
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6427<!-- _______________________________________________________________________ -->
6428<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]6429 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6430</div>
6431
6432<div class="doc_text">
6433
6434<h5>Syntax:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6435<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6436any integer bit width.
6437</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6438<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]6439 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6440 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6441 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6442 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6443 declare i256 @llvm.annotation.i256(i256 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6444</pre>
6445
6446<h5>Overview:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6447
6448<p>
6449The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6450</p>
6451
6452<h5>Arguments:</h5>
6453
6454<p>
6455The first argument is an integer value (result of some expression),
6456the second is a pointer to a global string, the third is a pointer to a global
6457string which is the source file name, and the last argument is the line number.
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6458It returns the value of the first argument.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6459</p>
6460
6461<h5>Semantics:</h5>
6462
6463<p>
6464This intrinsic allows annotations to be put on arbitrary expressions
6465with arbitrary strings. This can be useful for special purpose optimizations
6466that want to look for these annotations. These have no other defined use, they
6467are ignored by code generation and optimization.
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6468</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6469</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6470
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6471<!-- _______________________________________________________________________ -->
6472<div class="doc_subsubsection">
6473 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6474</div>
6475
6476<div class="doc_text">
6477
6478<h5>Syntax:</h5>
6479<pre>
6480 declare void @llvm.trap()
6481</pre>
6482
6483<h5>Overview:</h5>
6484
6485<p>
6486The '<tt>llvm.trap</tt>' intrinsic
6487</p>
6488
6489<h5>Arguments:</h5>
6490
6491<p>
6492None
6493</p>
6494
6495<h5>Semantics:</h5>
6496
6497<p>
6498This intrinsics is lowered to the target dependent trap instruction. If the
6499target does not have a trap instruction, this intrinsic will be lowered to the
6500call of the abort() function.
6501</p>
6502</div>
6503
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6504<!-- _______________________________________________________________________ -->
6505<div class="doc_subsubsection">
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]6506 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6507</div>
6508<div class="doc_text">
6509<h5>Syntax:</h5>
6510<pre>
6511declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
6512
6513</pre>
6514<h5>Overview:</h5>
6515<p>
6516 The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
6517 it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
6518 it is placed on the stack before local variables.
6519</p>
6520<h5>Arguments:</h5>
6521<p>
6522 The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
6523 first argument is the value loaded from the stack guard
6524 <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
6525 has enough space to hold the value of the guard.
6526</p>
6527<h5>Semantics:</h5>
6528<p>
6529 This intrinsic causes the prologue/epilogue inserter to force the position of
6530 the <tt>AllocaInst</tt> stack slot to be before local variables on the
6531 stack. This is to ensure that if a local variable on the stack is overwritten,
6532 it will destroy the value of the guard. When the function exits, the guard on
6533 the stack is checked against the original guard. If they're different, then
6534 the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
6535</p>
6536</div>
6537
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6538<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6539<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6540<address>
6541 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]6542 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6543 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]6544 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6545
6546 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]6547 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6548 Last modified: $Date$
6549</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]6550
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6551</body>
6552</html>