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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 55e459aa7508fb7f7de89886060f5fb5526efa44 / . / 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>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a>
24 <ol>
Bill Wendling987e7eb2009-07-20 02:41:50 +0000[diff] [blame]25 <li><a href="#linkage_private">'<tt>private</tt>' Linkage</a></li>
26 <li><a href="#linkage_linker_private">'<tt>linker_private</tt>' Linkage</a></li>
27 <li><a href="#linkage_internal">'<tt>internal</tt>' Linkage</a></li>
28 <li><a href="#linkage_available_externally">'<tt>available_externally</tt>' Linkage</a></li>
29 <li><a href="#linkage_linkonce">'<tt>linkonce</tt>' Linkage</a></li>
30 <li><a href="#linkage_common">'<tt>common</tt>' Linkage</a></li>
31 <li><a href="#linkage_weak">'<tt>weak</tt>' Linkage</a></li>
32 <li><a href="#linkage_appending">'<tt>appending</tt>' Linkage</a></li>
33 <li><a href="#linkage_externweak">'<tt>extern_weak</tt>' Linkage</a></li>
34 <li><a href="#linkage_linkonce">'<tt>linkonce_odr</tt>' Linkage</a></li>
35 <li><a href="#linkage_weak">'<tt>weak_odr</tt>' Linkage</a></li>
36 <li><a href="#linkage_external">'<tt>externally visible</tt>' Linkage</a></li>
37 <li><a href="#linkage_dllimport">'<tt>dllimport</tt>' Linkage</a></li>
38 <li><a href="#linkage_dllexport">'<tt>dllexport</tt>' Linkage</a></li>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]39 </ol>
40 </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]41 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]42 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]43 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]44 <li><a href="#functionstructure">Functions</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]45 <li><a href="#aliasstructure">Aliases</a></li>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]46 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]47 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]48 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]49 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]50 <li><a href="#datalayout">Data Layout</a></li>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]51 <li><a href="#pointeraliasing">Pointer Aliasing Rules</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]52 </ol>
53 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]54 <li><a href="#typesystem">Type System</a>
55 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]56 <li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]57 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]58 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]59 <li><a href="#t_floating">Floating Point Types</a></li>
60 <li><a href="#t_void">Void Type</a></li>
61 <li><a href="#t_label">Label Type</a></li>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]62 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]63 </ol>
64 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]65 <li><a href="#t_derived">Derived Types</a>
66 <ol>
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]67 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]68 <li><a href="#t_array">Array Type</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]69 <li><a href="#t_function">Function Type</a></li>
70 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]71 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]72 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]73 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]74 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]75 </ol>
76 </li>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]77 <li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]78 </ol>
79 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]80 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]81 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]82 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]83 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]84 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
85 <li><a href="#undefvalues">Undefined Values</a></li>
86 <li><a href="#constantexprs">Constant Expressions</a></li>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]87 <li><a href="#metadata">Embedded Metadata</a></li>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]88 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]89 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]90 <li><a href="#othervalues">Other Values</a>
91 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]92 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]93 </ol>
94 </li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]95 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
96 <ol>
97 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]98 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
99 Global Variable</a></li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]100 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
101 Global Variable</a></li>
102 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
103 Global Variable</a></li>
104 </ol>
105 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]106 <li><a href="#instref">Instruction Reference</a>
107 <ol>
108 <li><a href="#terminators">Terminator Instructions</a>
109 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]110 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
111 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]112 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
113 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]114 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]115 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]116 </ol>
117 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]118 <li><a href="#binaryops">Binary Operations</a>
119 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]120 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]121 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]122 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]123 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]124 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]125 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]126 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
127 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
128 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]129 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
130 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
131 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]132 </ol>
133 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]134 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
135 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]136 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
137 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
138 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]139 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]140 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]141 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]142 </ol>
143 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]144 <li><a href="#vectorops">Vector Operations</a>
145 <ol>
146 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
147 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
148 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]149 </ol>
150 </li>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]151 <li><a href="#aggregateops">Aggregate Operations</a>
152 <ol>
153 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
154 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
155 </ol>
156 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]157 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]158 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]159 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
160 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
161 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]162 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
163 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
164 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]165 </ol>
166 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]167 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]168 <ol>
169 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
170 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
171 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
172 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
173 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]174 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
175 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
176 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
177 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]178 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
179 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]180 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]181 </ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]182 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]183 <li><a href="#otherops">Other Operations</a>
184 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]185 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
186 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]187 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]188 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]189 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]190 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]191 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]192 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]193 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]194 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]195 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]196 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]197 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
198 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]199 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
200 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
201 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]202 </ol>
203 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]204 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
205 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]206 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
207 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
208 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]209 </ol>
210 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]211 <li><a href="#int_codegen">Code Generator Intrinsics</a>
212 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]213 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
214 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
215 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
216 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
217 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
218 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
219 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]220 </ol>
221 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]222 <li><a href="#int_libc">Standard C Library Intrinsics</a>
223 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]224 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
225 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
226 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
227 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
228 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]229 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
230 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
231 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]232 </ol>
233 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]234 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]235 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]236 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]237 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
238 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
239 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]240 </ol>
241 </li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]242 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
243 <ol>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]244 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
245 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
246 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
247 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
248 <li><a href="#int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]249 <li><a href="#int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]250 </ol>
251 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]252 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]253 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]254 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]255 <ol>
256 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]257 </ol>
258 </li>
Bill Wendling3c44f5b2008-11-18 22:10:53 +0000[diff] [blame]259 <li><a href="#int_atomics">Atomic intrinsics</a>
260 <ol>
261 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
262 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
263 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
264 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
265 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
266 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
267 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
268 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
269 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
270 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
271 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
272 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
273 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
274 </ol>
275 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]276 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]277 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]278 <li><a href="#int_var_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]279 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]280 <li><a href="#int_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]281 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]282 <li><a href="#int_trap">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]283 '<tt>llvm.trap</tt>' Intrinsic</a></li>
284 <li><a href="#int_stackprotector">
285 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]286 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]287 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]288 </ol>
289 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]290</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]291
292<div class="doc_author">
293 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
294 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]295</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]296
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]297<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]298<div class="doc_section"> <a name="abstract">Abstract </a></div>
299<!-- *********************************************************************** -->
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">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]302
303<p>This document is a reference manual for the LLVM assembly language. LLVM is
304 a Static Single Assignment (SSA) based representation that provides type
305 safety, low-level operations, flexibility, and the capability of representing
306 'all' high-level languages cleanly. It is the common code representation
307 used throughout all phases of the LLVM compilation strategy.</p>
308
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]309</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]310
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]311<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]312<div class="doc_section"> <a name="introduction">Introduction</a> </div>
313<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]314
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]315<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]316
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]317<p>The LLVM code representation is designed to be used in three different forms:
318 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
319 for fast loading by a Just-In-Time compiler), and as a human readable
320 assembly language representation. This allows LLVM to provide a powerful
321 intermediate representation for efficient compiler transformations and
322 analysis, while providing a natural means to debug and visualize the
323 transformations. The three different forms of LLVM are all equivalent. This
324 document describes the human readable representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]325
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]326<p>The LLVM representation aims to be light-weight and low-level while being
327 expressive, typed, and extensible at the same time. It aims to be a
328 "universal IR" of sorts, by being at a low enough level that high-level ideas
329 may be cleanly mapped to it (similar to how microprocessors are "universal
330 IR's", allowing many source languages to be mapped to them). By providing
331 type information, LLVM can be used as the target of optimizations: for
332 example, through pointer analysis, it can be proven that a C automatic
333 variable is never accessed outside of the current function... allowing it to
334 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]335
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]336</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]337
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]338<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]339<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]340
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]341<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]342
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]343<p>It is important to note that this document describes 'well formed' LLVM
344 assembly language. There is a difference between what the parser accepts and
345 what is considered 'well formed'. For example, the following instruction is
346 syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]347
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]348<div class="doc_code">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]349<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]350%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]351</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]352</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]353
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]354<p>...because the definition of <tt>%x</tt> does not dominate all of its
355 uses. The LLVM infrastructure provides a verification pass that may be used
356 to verify that an LLVM module is well formed. This pass is automatically run
357 by the parser after parsing input assembly and by the optimizer before it
358 outputs bitcode. The violations pointed out by the verifier pass indicate
359 bugs in transformation passes or input to the parser.</p>
360
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]361</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]362
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]363<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]364
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]365<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]366<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]367<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]368
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]369<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]370
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]371<p>LLVM identifiers come in two basic types: global and local. Global
372 identifiers (functions, global variables) begin with the <tt>'@'</tt>
373 character. Local identifiers (register names, types) begin with
374 the <tt>'%'</tt> character. Additionally, there are three different formats
375 for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]376
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]377<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]378 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]379 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
380 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
381 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
382 other characters in their names can be surrounded with quotes. Special
383 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
384 ASCII code for the character in hexadecimal. In this way, any character
385 can be used in a name value, even quotes themselves.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]386
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]387 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]388 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]389
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]390 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]391 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]392</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]393
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]394<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]395 don't need to worry about name clashes with reserved words, and the set of
396 reserved words may be expanded in the future without penalty. Additionally,
397 unnamed identifiers allow a compiler to quickly come up with a temporary
398 variable without having to avoid symbol table conflicts.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]399
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]400<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]401 languages. There are keywords for different opcodes
402 ('<tt><a href="#i_add">add</a></tt>',
403 '<tt><a href="#i_bitcast">bitcast</a></tt>',
404 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
405 ('<tt><a href="#t_void">void</a></tt>',
406 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
407 reserved words cannot conflict with variable names, because none of them
408 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]409
410<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]411 '<tt>%X</tt>' by 8:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]412
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]413<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]414
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]415<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]416<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]417%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]418</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]419</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]420
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]421<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]422
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]423<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]424<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]425%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]426</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]427</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]428
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]429<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]430
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]431<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]432<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]433<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
434<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
435%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]436</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]437</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]438
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]439<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
440 lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]441
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]442<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]443 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]444 line.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]445
446 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]447 assigned to a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]448
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]449 <li>Unnamed temporaries are numbered sequentially</li>
450</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]451
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]452<p>...and it also shows a convention that we follow in this document. When
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]453 demonstrating instructions, we will follow an instruction with a comment that
454 defines the type and name of value produced. Comments are shown in italic
455 text.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]456
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]457</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]458
459<!-- *********************************************************************** -->
460<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
461<!-- *********************************************************************** -->
462
463<!-- ======================================================================= -->
464<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
465</div>
466
467<div class="doc_text">
468
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]469<p>LLVM programs are composed of "Module"s, each of which is a translation unit
470 of the input programs. Each module consists of functions, global variables,
471 and symbol table entries. Modules may be combined together with the LLVM
472 linker, which merges function (and global variable) definitions, resolves
473 forward declarations, and merges symbol table entries. Here is an example of
474 the "hello world" module:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]475
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]476<div class="doc_code">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]477<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]478<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
479 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]480
481<i>; External declaration of the puts function</i>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]482<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]483
484<i>; Definition of main function</i>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]485define i32 @main() { <i>; i32()* </i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]486 <i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]487 %cast210 = <a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]488 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]489
490 <i>; Call puts function to write out the string to stdout...</i>
491 <a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]492 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]493 <a
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]494 href="#i_ret">ret</a> i32 0<br>}<br>
495</pre>
496</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]497
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]498<p>This example is made up of a <a href="#globalvars">global variable</a> named
499 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function, and
500 a <a href="#functionstructure">function definition</a> for
501 "<tt>main</tt>".</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]502
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]503<p>In general, a module is made up of a list of global values, where both
504 functions and global variables are global values. Global values are
505 represented by a pointer to a memory location (in this case, a pointer to an
506 array of char, and a pointer to a function), and have one of the
507 following <a href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]508
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]509</div>
510
511<!-- ======================================================================= -->
512<div class="doc_subsection">
513 <a name="linkage">Linkage Types</a>
514</div>
515
516<div class="doc_text">
517
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]518<p>All Global Variables and Functions have one of the following types of
519 linkage:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]520
521<dl>
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]522 <dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]523 <dd>Global values with private linkage are only directly accessible by objects
524 in the current module. In particular, linking code into a module with an
525 private global value may cause the private to be renamed as necessary to
526 avoid collisions. Because the symbol is private to the module, all
527 references can be updated. This doesn't show up in any symbol table in the
528 object file.</dd>
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]529
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]530 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt>: </dt>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]531 <dd>Similar to private, but the symbol is passed through the assembler and
532 removed by the linker after evaluation.</dd>
533
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]534 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]535 <dd>Similar to private, but the value shows as a local symbol
536 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
537 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]538
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]539 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt>: </dt>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]540 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]541 into the object file corresponding to the LLVM module. They exist to
542 allow inlining and other optimizations to take place given knowledge of
543 the definition of the global, which is known to be somewhere outside the
544 module. Globals with <tt>available_externally</tt> linkage are allowed to
545 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
546 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]547
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]548 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]549 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]550 the same name when linkage occurs. This is typically used to implement
551 inline functions, templates, or other code which must be generated in each
552 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
553 allowed to be discarded.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]554
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]555 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]556 <dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
557 linkage, except that unreferenced <tt>common</tt> globals may not be
558 discarded. This is used for globals that may be emitted in multiple
559 translation units, but that are not guaranteed to be emitted into every
560 translation unit that uses them. One example of this is tentative
561 definitions in C, such as "<tt>int X;</tt>" at global scope.</dd>
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]562
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]563 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]564 <dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]565 that some targets may choose to emit different assembly sequences for them
566 for target-dependent reasons. This is used for globals that are declared
567 "weak" in C source code.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]568
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]569 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]570 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]571 pointer to array type. When two global variables with appending linkage
572 are linked together, the two global arrays are appended together. This is
573 the LLVM, typesafe, equivalent of having the system linker append together
574 "sections" with identical names when .o files are linked.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]575
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]576 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]577 <dd>The semantics of this linkage follow the ELF object file model: the symbol
578 is weak until linked, if not linked, the symbol becomes null instead of
579 being an undefined reference.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]580
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]581 <dt><tt><b><a name="linkage_linkonce">linkonce_odr</a></b></tt>: </dt>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]582 <dt><tt><b><a name="linkage_weak">weak_odr</a></b></tt>: </dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]583 <dd>Some languages allow differing globals to be merged, such as two functions
584 with different semantics. Other languages, such as <tt>C++</tt>, ensure
585 that only equivalent globals are ever merged (the "one definition rule" -
586 "ODR"). Such languages can use the <tt>linkonce_odr</tt>
587 and <tt>weak_odr</tt> linkage types to indicate that the global will only
588 be merged with equivalent globals. These linkage types are otherwise the
589 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]590
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]591 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]592 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]593 visible, meaning that it participates in linkage and can be used to
594 resolve external symbol references.</dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]595</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]596
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]597<p>The next two types of linkage are targeted for Microsoft Windows platform
598 only. They are designed to support importing (exporting) symbols from (to)
599 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]600
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]601<dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]602 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]603 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]604 or variable via a global pointer to a pointer that is set up by the DLL
605 exporting the symbol. On Microsoft Windows targets, the pointer name is
606 formed by combining <code>__imp_</code> and the function or variable
607 name.</dd>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]608
609 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]610 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]611 pointer to a pointer in a DLL, so that it can be referenced with the
612 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
613 name is formed by combining <code>__imp_</code> and the function or
614 variable name.</dd>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]615</dl>
616
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]617<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
618 another module defined a "<tt>.LC0</tt>" variable and was linked with this
619 one, one of the two would be renamed, preventing a collision. Since
620 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
621 declarations), they are accessible outside of the current module.</p>
622
623<p>It is illegal for a function <i>declaration</i> to have any linkage type
624 other than "externally visible", <tt>dllimport</tt>
625 or <tt>extern_weak</tt>.</p>
626
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]627<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]628 or <tt>weak_odr</tt> linkages.</p>
629
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]630</div>
631
632<!-- ======================================================================= -->
633<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]634 <a name="callingconv">Calling Conventions</a>
635</div>
636
637<div class="doc_text">
638
639<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]640 and <a href="#i_invoke">invokes</a> can all have an optional calling
641 convention specified for the call. The calling convention of any pair of
642 dynamic caller/callee must match, or the behavior of the program is
643 undefined. The following calling conventions are supported by LLVM, and more
644 may be added in the future:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]645
646<dl>
647 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]648 <dd>This calling convention (the default if no other calling convention is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]649 specified) matches the target C calling conventions. This calling
650 convention supports varargs function calls and tolerates some mismatch in
651 the declared prototype and implemented declaration of the function (as
652 does normal C).</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]653
654 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]655 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]656 (e.g. by passing things in registers). This calling convention allows the
657 target to use whatever tricks it wants to produce fast code for the
658 target, without having to conform to an externally specified ABI
659 (Application Binary Interface). Implementations of this convention should
660 allow arbitrary <a href="CodeGenerator.html#tailcallopt">tail call
661 optimization</a> to be supported. This calling convention does not
662 support varargs and requires the prototype of all callees to exactly match
663 the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]664
665 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]666 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]667 as possible under the assumption that the call is not commonly executed.
668 As such, these calls often preserve all registers so that the call does
669 not break any live ranges in the caller side. This calling convention
670 does not support varargs and requires the prototype of all callees to
671 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]672
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]673 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]674 <dd>Any calling convention may be specified by number, allowing
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]675 target-specific calling conventions to be used. Target specific calling
676 conventions start at 64.</dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]677</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]678
679<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]680 support Pascal conventions or any other well-known target-independent
681 convention.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]682
683</div>
684
685<!-- ======================================================================= -->
686<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]687 <a name="visibility">Visibility Styles</a>
688</div>
689
690<div class="doc_text">
691
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]692<p>All Global Variables and Functions have one of the following visibility
693 styles:</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]694
695<dl>
696 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]697 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]698 that the declaration is visible to other modules and, in shared libraries,
699 means that the declared entity may be overridden. On Darwin, default
700 visibility means that the declaration is visible to other modules. Default
701 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]702
703 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]704 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]705 object if they are in the same shared object. Usually, hidden visibility
706 indicates that the symbol will not be placed into the dynamic symbol
707 table, so no other module (executable or shared library) can reference it
708 directly.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]709
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]710 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]711 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]712 the dynamic symbol table, but that references within the defining module
713 will bind to the local symbol. That is, the symbol cannot be overridden by
714 another module.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]715</dl>
716
717</div>
718
719<!-- ======================================================================= -->
720<div class="doc_subsection">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]721 <a name="namedtypes">Named Types</a>
722</div>
723
724<div class="doc_text">
725
726<p>LLVM IR allows you to specify name aliases for certain types. This can make
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]727 it easier to read the IR and make the IR more condensed (particularly when
728 recursive types are involved). An example of a name specification is:</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]729
730<div class="doc_code">
731<pre>
732%mytype = type { %mytype*, i32 }
733</pre>
734</div>
735
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]736<p>You may give a name to any <a href="#typesystem">type</a> except
737 "<a href="t_void">void</a>". Type name aliases may be used anywhere a type
738 is expected with the syntax "%mytype".</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]739
740<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]741 and that you can therefore specify multiple names for the same type. This
742 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
743 uses structural typing, the name is not part of the type. When printing out
744 LLVM IR, the printer will pick <em>one name</em> to render all types of a
745 particular shape. This means that if you have code where two different
746 source types end up having the same LLVM type, that the dumper will sometimes
747 print the "wrong" or unexpected type. This is an important design point and
748 isn't going to change.</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]749
750</div>
751
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]752<!-- ======================================================================= -->
753<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]754 <a name="globalvars">Global Variables</a>
755</div>
756
757<div class="doc_text">
758
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]759<p>Global variables define regions of memory allocated at compilation time
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]760 instead of run-time. Global variables may optionally be initialized, may
761 have an explicit section to be placed in, and may have an optional explicit
762 alignment specified. A variable may be defined as "thread_local", which
763 means that it will not be shared by threads (each thread will have a
764 separated copy of the variable). A variable may be defined as a global
765 "constant," which indicates that the contents of the variable
766 will <b>never</b> be modified (enabling better optimization, allowing the
767 global data to be placed in the read-only section of an executable, etc).
768 Note that variables that need runtime initialization cannot be marked
769 "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]770
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]771<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
772 constant, even if the final definition of the global is not. This capability
773 can be used to enable slightly better optimization of the program, but
774 requires the language definition to guarantee that optimizations based on the
775 'constantness' are valid for the translation units that do not include the
776 definition.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]777
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]778<p>As SSA values, global variables define pointer values that are in scope
779 (i.e. they dominate) all basic blocks in the program. Global variables
780 always define a pointer to their "content" type because they describe a
781 region of memory, and all memory objects in LLVM are accessed through
782 pointers.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]783
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]784<p>A global variable may be declared to reside in a target-specific numbered
785 address space. For targets that support them, address spaces may affect how
786 optimizations are performed and/or what target instructions are used to
787 access the variable. The default address space is zero. The address space
788 qualifier must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]789
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]790<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]791 supports it, it will emit globals to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]792
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]793<p>An explicit alignment may be specified for a global. If not present, or if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]794 the alignment is set to zero, the alignment of the global is set by the
795 target to whatever it feels convenient. If an explicit alignment is
796 specified, the global is forced to have at least that much alignment. All
797 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]798
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]799<p>For example, the following defines a global in a numbered address space with
800 an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]801
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]802<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]803<pre>
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]804@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]805</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]806</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]807
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]808</div>
809
810
811<!-- ======================================================================= -->
812<div class="doc_subsection">
813 <a name="functionstructure">Functions</a>
814</div>
815
816<div class="doc_text">
817
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]818<p>LLVM function definitions consist of the "<tt>define</tt>" keyord, an
819 optional <a href="#linkage">linkage type</a>, an optional
820 <a href="#visibility">visibility style</a>, an optional
821 <a href="#callingconv">calling convention</a>, a return type, an optional
822 <a href="#paramattrs">parameter attribute</a> for the return type, a function
823 name, a (possibly empty) argument list (each with optional
824 <a href="#paramattrs">parameter attributes</a>), optional
825 <a href="#fnattrs">function attributes</a>, an optional section, an optional
826 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
827 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]828
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]829<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
830 optional <a href="#linkage">linkage type</a>, an optional
831 <a href="#visibility">visibility style</a>, an optional
832 <a href="#callingconv">calling convention</a>, a return type, an optional
833 <a href="#paramattrs">parameter attribute</a> for the return type, a function
834 name, a possibly empty list of arguments, an optional alignment, and an
835 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]836
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]837<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]838 (Control Flow Graph) for the function. Each basic block may optionally start
839 with a label (giving the basic block a symbol table entry), contains a list
840 of instructions, and ends with a <a href="#terminators">terminator</a>
841 instruction (such as a branch or function return).</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]842
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]843<p>The first basic block in a function is special in two ways: it is immediately
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]844 executed on entrance to the function, and it is not allowed to have
845 predecessor basic blocks (i.e. there can not be any branches to the entry
846 block of a function). Because the block can have no predecessors, it also
847 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]848
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]849<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]850 supports it, it will emit functions to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]851
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]852<p>An explicit alignment may be specified for a function. If not present, or if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]853 the alignment is set to zero, the alignment of the function is set by the
854 target to whatever it feels convenient. If an explicit alignment is
855 specified, the function is forced to have at least that much alignment. All
856 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]857
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]858<h5>Syntax:</h5>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]859<div class="doc_code">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]860<pre>
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]861define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]862 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
863 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
864 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
865 [<a href="#gc">gc</a>] { ... }
866</pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]867</div>
868
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]869</div>
870
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]871<!-- ======================================================================= -->
872<div class="doc_subsection">
873 <a name="aliasstructure">Aliases</a>
874</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]875
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]876<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]877
878<p>Aliases act as "second name" for the aliasee value (which can be either
879 function, global variable, another alias or bitcast of global value). Aliases
880 may have an optional <a href="#linkage">linkage type</a>, and an
881 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]882
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]883<h5>Syntax:</h5>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]884<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]885<pre>
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]886@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]887</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]888</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]889
890</div>
891
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]892<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]893<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]894
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]895<div class="doc_text">
896
897<p>The return type and each parameter of a function type may have a set of
898 <i>parameter attributes</i> associated with them. Parameter attributes are
899 used to communicate additional information about the result or parameters of
900 a function. Parameter attributes are considered to be part of the function,
901 not of the function type, so functions with different parameter attributes
902 can have the same function type.</p>
903
904<p>Parameter attributes are simple keywords that follow the type specified. If
905 multiple parameter attributes are needed, they are space separated. For
906 example:</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]907
908<div class="doc_code">
909<pre>
Nick Lewyckyb6a7d252009-02-15 23:06:14 +0000[diff] [blame]910declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]911declare i32 @atoi(i8 zeroext)
912declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]913</pre>
914</div>
915
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]916<p>Note that any attributes for the function result (<tt>nounwind</tt>,
917 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]918
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]919<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]920
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]921<dl>
922 <dt><tt>zeroext</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]923 <dd>This indicates to the code generator that the parameter or return value
924 should be zero-extended to a 32-bit value by the caller (for a parameter)
925 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]926
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]927 <dt><tt>signext</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]928 <dd>This indicates to the code generator that the parameter or return value
929 should be sign-extended to a 32-bit value by the caller (for a parameter)
930 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]931
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]932 <dt><tt>inreg</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]933 <dd>This indicates that this parameter or return value should be treated in a
934 special target-dependent fashion during while emitting code for a function
935 call or return (usually, by putting it in a register as opposed to memory,
936 though some targets use it to distinguish between two different kinds of
937 registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]938
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]939 <dt><tt><a name="byval">byval</a></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]940 <dd>This indicates that the pointer parameter should really be passed by value
941 to the function. The attribute implies that a hidden copy of the pointee
942 is made between the caller and the callee, so the callee is unable to
943 modify the value in the callee. This attribute is only valid on LLVM
944 pointer arguments. It is generally used to pass structs and arrays by
945 value, but is also valid on pointers to scalars. The copy is considered
946 to belong to the caller not the callee (for example,
947 <tt><a href="#readonly">readonly</a></tt> functions should not write to
948 <tt>byval</tt> parameters). This is not a valid attribute for return
949 values. The byval attribute also supports specifying an alignment with
950 the align attribute. This has a target-specific effect on the code
951 generator that usually indicates a desired alignment for the synthesized
952 stack slot.</dd>
953
954 <dt><tt>sret</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]955 <dd>This indicates that the pointer parameter specifies the address of a
956 structure that is the return value of the function in the source program.
957 This pointer must be guaranteed by the caller to be valid: loads and
958 stores to the structure may be assumed by the callee to not to trap. This
959 may only be applied to the first parameter. This is not a valid attribute
960 for return values. </dd>
961
962 <dt><tt>noalias</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]963 <dd>This indicates that the pointer does not alias any global or any other
964 parameter. The caller is responsible for ensuring that this is the
965 case. On a function return value, <tt>noalias</tt> additionally indicates
966 that the pointer does not alias any other pointers visible to the
967 caller. For further details, please see the discussion of the NoAlias
968 response in
969 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
970 analysis</a>.</dd>
971
972 <dt><tt>nocapture</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]973 <dd>This indicates that the callee does not make any copies of the pointer
974 that outlive the callee itself. This is not a valid attribute for return
975 values.</dd>
976
977 <dt><tt>nest</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]978 <dd>This indicates that the pointer parameter can be excised using the
979 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
980 attribute for return values.</dd>
981</dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]982
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]983</div>
984
985<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]986<div class="doc_subsection">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]987 <a name="gc">Garbage Collector Names</a>
988</div>
989
990<div class="doc_text">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]991
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]992<p>Each function may specify a garbage collector name, which is simply a
993 string:</p>
994
995<div class="doc_code">
996<pre>
997define void @f() gc "name" { ...
998</pre>
999</div>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1000
1001<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1002 collector which will cause the compiler to alter its output in order to
1003 support the named garbage collection algorithm.</p>
1004
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1005</div>
1006
1007<!-- ======================================================================= -->
1008<div class="doc_subsection">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1009 <a name="fnattrs">Function Attributes</a>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1010</div>
1011
1012<div class="doc_text">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1013
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1014<p>Function attributes are set to communicate additional information about a
1015 function. Function attributes are considered to be part of the function, not
1016 of the function type, so functions with different parameter attributes can
1017 have the same function type.</p>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1018
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1019<p>Function attributes are simple keywords that follow the type specified. If
1020 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1021
1022<div class="doc_code">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1023<pre>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1024define void @f() noinline { ... }
1025define void @f() alwaysinline { ... }
1026define void @f() alwaysinline optsize { ... }
1027define void @f() optsize
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1028</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1029</div>
1030
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1031<dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1032 <dt><tt>alwaysinline</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1033 <dd>This attribute indicates that the inliner should attempt to inline this
1034 function into callers whenever possible, ignoring any active inlining size
1035 threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1036
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1037 <dt><tt>noinline</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1038 <dd>This attribute indicates that the inliner should never inline this
1039 function in any situation. This attribute may not be used together with
1040 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1041
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1042 <dt><tt>optsize</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1043 <dd>This attribute suggests that optimization passes and code generator passes
1044 make choices that keep the code size of this function low, and otherwise
1045 do optimizations specifically to reduce code size.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1046
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1047 <dt><tt>noreturn</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1048 <dd>This function attribute indicates that the function never returns
1049 normally. This produces undefined behavior at runtime if the function
1050 ever does dynamically return.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1051
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1052 <dt><tt>nounwind</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1053 <dd>This function attribute indicates that the function never returns with an
1054 unwind or exceptional control flow. If the function does unwind, its
1055 runtime behavior is undefined.</dd>
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1056
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1057 <dt><tt>readnone</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1058 <dd>This attribute indicates that the function computes its result (or decides
1059 to unwind an exception) based strictly on its arguments, without
1060 dereferencing any pointer arguments or otherwise accessing any mutable
1061 state (e.g. memory, control registers, etc) visible to caller functions.
1062 It does not write through any pointer arguments
1063 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1064 changes any state visible to callers. This means that it cannot unwind
1065 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1066 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel5d96fda2009-06-12 19:45:19 +0000[diff] [blame]1067
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1068 <dt><tt><a name="readonly">readonly</a></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1069 <dd>This attribute indicates that the function does not write through any
1070 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1071 arguments) or otherwise modify any state (e.g. memory, control registers,
1072 etc) visible to caller functions. It may dereference pointer arguments
1073 and read state that may be set in the caller. A readonly function always
1074 returns the same value (or unwinds an exception identically) when called
1075 with the same set of arguments and global state. It cannot unwind an
1076 exception by calling the <tt>C++</tt> exception throwing methods, but may
1077 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc5ec8a72009-07-17 18:07:26 +0000[diff] [blame]1078
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1079 <dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1080 <dd>This attribute indicates that the function should emit a stack smashing
1081 protector. It is in the form of a "canary"&mdash;a random value placed on
1082 the stack before the local variables that's checked upon return from the
1083 function to see if it has been overwritten. A heuristic is used to
1084 determine if a function needs stack protectors or not.<br>
1085<br>
1086 If a function that has an <tt>ssp</tt> attribute is inlined into a
1087 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1088 function will have an <tt>ssp</tt> attribute.</dd>
1089
1090 <dt><tt>sspreq</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1091 <dd>This attribute indicates that the function should <em>always</em> emit a
1092 stack smashing protector. This overrides
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1093 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1094<br>
1095 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1096 function that doesn't have an <tt>sspreq</tt> attribute or which has
1097 an <tt>ssp</tt> attribute, then the resulting function will have
1098 an <tt>sspreq</tt> attribute.</dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1099
1100 <dt><tt>noredzone</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1101 <dd>This attribute indicates that the code generator should not use a red
1102 zone, even if the target-specific ABI normally permits it.</dd>
1103
1104 <dt><tt>noimplicitfloat</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1105 <dd>This attributes disables implicit floating point instructions.</dd>
1106
1107 <dt><tt>naked</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1108 <dd>This attribute disables prologue / epilogue emission for the function.
1109 This can have very system-specific consequences.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1110</dl>
1111
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1112</div>
1113
1114<!-- ======================================================================= -->
1115<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1116 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1117</div>
1118
1119<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1120
1121<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1122 the GCC "file scope inline asm" blocks. These blocks are internally
1123 concatenated by LLVM and treated as a single unit, but may be separated in
1124 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1125
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1126<div class="doc_code">
1127<pre>
1128module asm "inline asm code goes here"
1129module asm "more can go here"
1130</pre>
1131</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1132
1133<p>The strings can contain any character by escaping non-printable characters.
1134 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1135 for the number.</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1136
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1137<p>The inline asm code is simply printed to the machine code .s file when
1138 assembly code is generated.</p>
1139
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1140</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1141
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1142<!-- ======================================================================= -->
1143<div class="doc_subsection">
1144 <a name="datalayout">Data Layout</a>
1145</div>
1146
1147<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1148
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1149<p>A module may specify a target specific data layout string that specifies how
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1150 data is to be laid out in memory. The syntax for the data layout is
1151 simply:</p>
1152
1153<div class="doc_code">
1154<pre>
1155target datalayout = "<i>layout specification</i>"
1156</pre>
1157</div>
1158
1159<p>The <i>layout specification</i> consists of a list of specifications
1160 separated by the minus sign character ('-'). Each specification starts with
1161 a letter and may include other information after the letter to define some
1162 aspect of the data layout. The specifications accepted are as follows:</p>
1163
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1164<dl>
1165 <dt><tt>E</tt></dt>
1166 <dd>Specifies that the target lays out data in big-endian form. That is, the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1167 bits with the most significance have the lowest address location.</dd>
1168
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1169 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1170 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1171 the bits with the least significance have the lowest address
1172 location.</dd>
1173
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1174 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1175 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1176 <i>preferred</i> alignments. All sizes are in bits. Specifying
1177 the <i>pref</i> alignment is optional. If omitted, the
1178 preceding <tt>:</tt> should be omitted too.</dd>
1179
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1180 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1181 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1182 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1183
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1184 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1185 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1186 <i>size</i>.</dd>
1187
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1188 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1189 <dd>This specifies the alignment for a floating point type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1190 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1191 (double).</dd>
1192
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1193 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1194 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1195 <i>size</i>.</dd>
1196
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1197 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1198 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1199 <i>size</i>.</dd>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1200</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1201
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1202<p>When constructing the data layout for a given target, LLVM starts with a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1203 default set of specifications which are then (possibly) overriden by the
1204 specifications in the <tt>datalayout</tt> keyword. The default specifications
1205 are given in this list:</p>
1206
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1207<ul>
1208 <li><tt>E</tt> - big endian</li>
1209 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1210 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1211 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1212 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1213 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1214 <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]1215 alignment of 64-bits</li>
1216 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1217 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1218 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1219 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1220 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1221 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1222</ul>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1223
1224<p>When LLVM is determining the alignment for a given type, it uses the
1225 following rules:</p>
1226
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1227<ol>
1228 <li>If the type sought is an exact match for one of the specifications, that
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1229 specification is used.</li>
1230
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1231 <li>If no match is found, and the type sought is an integer type, then the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1232 smallest integer type that is larger than the bitwidth of the sought type
1233 is used. If none of the specifications are larger than the bitwidth then
1234 the the largest integer type is used. For example, given the default
1235 specifications above, the i7 type will use the alignment of i8 (next
1236 largest) while both i65 and i256 will use the alignment of i64 (largest
1237 specified).</li>
1238
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1239 <li>If no match is found, and the type sought is a vector type, then the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1240 largest vector type that is smaller than the sought vector type will be
1241 used as a fall back. This happens because &lt;128 x double&gt; can be
1242 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1243</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1244
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1245</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1246
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1247<!-- ======================================================================= -->
1248<div class="doc_subsection">
1249 <a name="pointeraliasing">Pointer Aliasing Rules</a>
1250</div>
1251
1252<div class="doc_text">
1253
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame^]1254<p>Any memory access must be done through a pointer value associated
Andreas Bolka99a82052009-07-27 20:37:10 +0000[diff] [blame]1255with an address range of the memory access, otherwise the behavior
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1256is undefined. Pointer values are associated with address ranges
1257according to the following rules:</p>
1258
1259<ul>
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame^]1260 <li>A pointer value formed from a
1261 <tt><a href="#i_getelementptr">getelementptr</a></tt> instruction
1262 is associated with the addresses associated with the first operand
1263 of the <tt>getelementptr</tt>.</li>
1264 <li>An address of a global variable is associated with the address
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1265 range of the variable's storage.</li>
1266 <li>The result value of an allocation instruction is associated with
1267 the address range of the allocated storage.</li>
1268 <li>A null pointer in the default address-space is associated with
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame^]1269 no address.</li>
1270 <li>A pointer value formed by an
1271 <tt><a href="#i_inttoptr">inttoptr</a></tt> is associated with all
1272 address ranges of all pointer values that contribute (directly or
1273 indirectly) to the computation of the pointer's value.</li>
1274 <li>The result value of a
1275 <tt><a href="#i_bitcast">bitcast</a></tt> is associated with all
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1276 addresses associated with the operand of the <tt>bitcast</tt>.</li>
1277 <li>An integer constant other than zero or a pointer value returned
1278 from a function not defined within LLVM may be associated with address
1279 ranges allocated through mechanisms other than those provided by
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame^]1280 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1281 allocated by mechanisms provided by LLVM.</li>
1282 </ul>
1283
1284<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame^]1285<tt><a href="#i_load">load</a></tt> merely indicates the size and
1286alignment of the memory from which to load, as well as the
1287interpretation of the value. The first operand of a
1288<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1289and alignment of the store.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1290
1291<p>Consequently, type-based alias analysis, aka TBAA, aka
1292<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1293LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1294additional information which specialized optimization passes may use
1295to implement type-based alias analysis.</p>
1296
1297</div>
1298
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1299<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1300<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1301<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1302
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1303<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1304
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1305<p>The LLVM type system is one of the most important features of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1306 intermediate representation. Being typed enables a number of optimizations
1307 to be performed on the intermediate representation directly, without having
1308 to do extra analyses on the side before the transformation. A strong type
1309 system makes it easier to read the generated code and enables novel analyses
1310 and transformations that are not feasible to perform on normal three address
1311 code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1312
1313</div>
1314
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1315<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1316<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1317Classifications</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1318
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1319<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1320
1321<p>The types fall into a few useful classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1322
1323<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1324 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1325 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1326 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1327 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1328 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1329 </tr>
1330 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1331 <td><a href="#t_floating">floating point</a></td>
1332 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1333 </tr>
1334 <tr>
1335 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1336 <td><a href="#t_integer">integer</a>,
1337 <a href="#t_floating">floating point</a>,
1338 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1339 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1340 <a href="#t_struct">structure</a>,
1341 <a href="#t_array">array</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1342 <a href="#t_label">label</a>,
1343 <a href="#t_metadata">metadata</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1344 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1345 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1346 <tr>
1347 <td><a href="#t_primitive">primitive</a></td>
1348 <td><a href="#t_label">label</a>,
1349 <a href="#t_void">void</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1350 <a href="#t_floating">floating point</a>,
1351 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1352 </tr>
1353 <tr>
1354 <td><a href="#t_derived">derived</a></td>
1355 <td><a href="#t_integer">integer</a>,
1356 <a href="#t_array">array</a>,
1357 <a href="#t_function">function</a>,
1358 <a href="#t_pointer">pointer</a>,
1359 <a href="#t_struct">structure</a>,
1360 <a href="#t_pstruct">packed structure</a>,
1361 <a href="#t_vector">vector</a>,
1362 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1363 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1364 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1365 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1366</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1367
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1368<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1369 important. Values of these types are the only ones which can be produced by
1370 instructions, passed as arguments, or used as operands to instructions.</p>
1371
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1372</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1373
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1374<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1375<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1376
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1377<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1378
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1379<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1380 system.</p>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1381
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1382</div>
1383
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1384<!-- _______________________________________________________________________ -->
1385<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1386
1387<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1388
1389<table>
1390 <tbody>
1391 <tr><th>Type</th><th>Description</th></tr>
1392 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1393 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1394 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1395 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1396 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1397 </tbody>
1398</table>
1399
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1400</div>
1401
1402<!-- _______________________________________________________________________ -->
1403<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1404
1405<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1406
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1407<h5>Overview:</h5>
1408<p>The void type does not represent any value and has no size.</p>
1409
1410<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1411<pre>
1412 void
1413</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1414
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1415</div>
1416
1417<!-- _______________________________________________________________________ -->
1418<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1419
1420<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1421
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1422<h5>Overview:</h5>
1423<p>The label type represents code labels.</p>
1424
1425<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1426<pre>
1427 label
1428</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1429
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1430</div>
1431
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1432<!-- _______________________________________________________________________ -->
1433<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
1434
1435<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1436
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1437<h5>Overview:</h5>
1438<p>The metadata type represents embedded metadata. The only derived type that
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1439 may contain metadata is <tt>metadata*</tt> or a function type that returns or
1440 takes metadata typed parameters, but not pointer to metadata types.</p>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1441
1442<h5>Syntax:</h5>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1443<pre>
1444 metadata
1445</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1446
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1447</div>
1448
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1449
1450<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1451<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1452
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1453<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1454
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1455<p>The real power in LLVM comes from the derived types in the system. This is
1456 what allows a programmer to represent arrays, functions, pointers, and other
1457 useful types. Note that these derived types may be recursive: For example,
1458 it is possible to have a two dimensional array.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1459
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1460</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1461
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1462<!-- _______________________________________________________________________ -->
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1463<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1464
1465<div class="doc_text">
1466
1467<h5>Overview:</h5>
1468<p>The integer type is a very simple derived type that simply specifies an
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1469 arbitrary bit width for the integer type desired. Any bit width from 1 bit to
1470 2^23-1 (about 8 million) can be specified.</p>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1471
1472<h5>Syntax:</h5>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1473<pre>
1474 iN
1475</pre>
1476
1477<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1478 value.</p>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1479
1480<h5>Examples:</h5>
1481<table class="layout">
Nick Lewycky86c48642009-05-24 02:46:06 +0000[diff] [blame]1482 <tr class="layout">
1483 <td class="left"><tt>i1</tt></td>
1484 <td class="left">a single-bit integer.</td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1485 </tr>
Nick Lewycky86c48642009-05-24 02:46:06 +0000[diff] [blame]1486 <tr class="layout">
1487 <td class="left"><tt>i32</tt></td>
1488 <td class="left">a 32-bit integer.</td>
1489 </tr>
1490 <tr class="layout">
1491 <td class="left"><tt>i1942652</tt></td>
1492 <td class="left">a really big integer of over 1 million bits.</td>
1493 </tr>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1494</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1495
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1496<p>Note that the code generator does not yet support large integer types to be
1497 used as function return types. The specific limit on how large a return type
1498 the code generator can currently handle is target-dependent; currently it's
1499 often 64 bits for 32-bit targets and 128 bits for 64-bit targets.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1500
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1501</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1502
1503<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1504<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1505
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1506<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1507
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1508<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1509<p>The array type is a very simple derived type that arranges elements
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1510 sequentially in memory. The array type requires a size (number of elements)
1511 and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1512
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1513<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1514<pre>
1515 [&lt;# elements&gt; x &lt;elementtype&gt;]
1516</pre>
1517
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1518<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1519 be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1520
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1521<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1522<table class="layout">
1523 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1524 <td class="left"><tt>[40 x i32]</tt></td>
1525 <td class="left">Array of 40 32-bit integer values.</td>
1526 </tr>
1527 <tr class="layout">
1528 <td class="left"><tt>[41 x i32]</tt></td>
1529 <td class="left">Array of 41 32-bit integer values.</td>
1530 </tr>
1531 <tr class="layout">
1532 <td class="left"><tt>[4 x i8]</tt></td>
1533 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1534 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1535</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1536<p>Here are some examples of multidimensional arrays:</p>
1537<table class="layout">
1538 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1539 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1540 <td class="left">3x4 array of 32-bit integer values.</td>
1541 </tr>
1542 <tr class="layout">
1543 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1544 <td class="left">12x10 array of single precision floating point values.</td>
1545 </tr>
1546 <tr class="layout">
1547 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1548 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1549 </tr>
1550</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1551
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1552<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1553 length array. Normally, accesses past the end of an array are undefined in
1554 LLVM (e.g. it is illegal to access the 5th element of a 3 element array). As
1555 a special case, however, zero length arrays are recognized to be variable
1556 length. This allows implementation of 'pascal style arrays' with the LLVM
1557 type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1558
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1559<p>Note that the code generator does not yet support large aggregate types to be
1560 used as function return types. The specific limit on how large an aggregate
1561 return type the code generator can currently handle is target-dependent, and
1562 also dependent on the aggregate element types.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1563
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1564</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1565
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1566<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1567<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1568
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1569<div class="doc_text">
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1570
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1571<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1572<p>The function type can be thought of as a function signature. It consists of
1573 a return type and a list of formal parameter types. The return type of a
1574 function type is a scalar type, a void type, or a struct type. If the return
1575 type is a struct type then all struct elements must be of first class types,
1576 and the struct must have at least one element.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1577
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1578<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1579<pre>
1580 &lt;returntype list&gt; (&lt;parameter list&gt;)
1581</pre>
1582
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1583<p>...where '<tt>&lt;parameter list&gt;</tt>' is a comma-separated list of type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1584 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1585 which indicates that the function takes a variable number of arguments.
1586 Variable argument functions can access their arguments with
1587 the <a href="#int_varargs">variable argument handling intrinsic</a>
1588 functions. '<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1589 <a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1590
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1591<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1592<table class="layout">
1593 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1594 <td class="left"><tt>i32 (i32)</tt></td>
1595 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1596 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1597 </tr><tr class="layout">
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]1598 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1599 </tt></td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1600 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1601 an <tt>i16</tt> that should be sign extended and a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1602 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1603 <tt>float</tt>.
1604 </td>
1605 </tr><tr class="layout">
1606 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1607 <td class="left">A vararg function that takes at least one
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1608 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1609 which returns an integer. This is the signature for <tt>printf</tt> in
1610 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1611 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1612 </tr><tr class="layout">
1613 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukmanb0a57aa2008-11-27 06:41:20 +0000[diff] [blame]1614 <td class="left">A function taking an <tt>i32</tt>, returning two
1615 <tt>i32</tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1616 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1617 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1618</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1619
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1620</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1621
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1622<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1623<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1624
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1625<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1626
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1627<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1628<p>The structure type is used to represent a collection of data members together
1629 in memory. The packing of the field types is defined to match the ABI of the
1630 underlying processor. The elements of a structure may be any type that has a
1631 size.</p>
1632
1633<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1634 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1635 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1636
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1637<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1638<pre>
1639 { &lt;type list&gt; }
1640</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1641
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1642<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1643<table class="layout">
1644 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1645 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1646 <td class="left">A triple of three <tt>i32</tt> values</td>
1647 </tr><tr class="layout">
1648 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1649 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1650 second element is a <a href="#t_pointer">pointer</a> to a
1651 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1652 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1653 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1654</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1655
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1656<p>Note that the code generator does not yet support large aggregate types to be
1657 used as function return types. The specific limit on how large an aggregate
1658 return type the code generator can currently handle is target-dependent, and
1659 also dependent on the aggregate element types.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1660
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1661</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1662
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1663<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1664<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1665</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1666
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1667<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1668
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1669<h5>Overview:</h5>
1670<p>The packed structure type is used to represent a collection of data members
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1671 together in memory. There is no padding between fields. Further, the
1672 alignment of a packed structure is 1 byte. The elements of a packed
1673 structure may be any type that has a size.</p>
1674
1675<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1676 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1677 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1678
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1679<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1680<pre>
1681 &lt; { &lt;type list&gt; } &gt;
1682</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1683
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1684<h5>Examples:</h5>
1685<table class="layout">
1686 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1687 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1688 <td class="left">A triple of three <tt>i32</tt> values</td>
1689 </tr><tr class="layout">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1690 <td class="left">
1691<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1692 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1693 second element is a <a href="#t_pointer">pointer</a> to a
1694 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1695 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1696 </tr>
1697</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1698
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1699</div>
1700
1701<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1702<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1703
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1704<div class="doc_text">
1705
1706<h5>Overview:</h5>
1707<p>As in many languages, the pointer type represents a pointer or reference to
1708 another object, which must live in memory. Pointer types may have an optional
1709 address space attribute defining the target-specific numbered address space
1710 where the pointed-to object resides. The default address space is zero.</p>
1711
1712<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
1713 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1714
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1715<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1716<pre>
1717 &lt;type&gt; *
1718</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1719
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1720<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1721<table class="layout">
1722 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]1723 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1724 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1725 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1726 </tr>
1727 <tr class="layout">
1728 <td class="left"><tt>i32 (i32 *) *</tt></td>
1729 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1730 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1731 <tt>i32</tt>.</td>
1732 </tr>
1733 <tr class="layout">
1734 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1735 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1736 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1737 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1738</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1739
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1740</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1741
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1742<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1743<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1744
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1745<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1746
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1747<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1748<p>A vector type is a simple derived type that represents a vector of elements.
1749 Vector types are used when multiple primitive data are operated in parallel
1750 using a single instruction (SIMD). A vector type requires a size (number of
1751 elements) and an underlying primitive data type. Vectors must have a power
1752 of two length (1, 2, 4, 8, 16 ...). Vector types are considered
1753 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1754
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1755<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1756<pre>
1757 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1758</pre>
1759
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1760<p>The number of elements is a constant integer value; elementtype may be any
1761 integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1762
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1763<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1764<table class="layout">
1765 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1766 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1767 <td class="left">Vector of 4 32-bit integer values.</td>
1768 </tr>
1769 <tr class="layout">
1770 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1771 <td class="left">Vector of 8 32-bit floating-point values.</td>
1772 </tr>
1773 <tr class="layout">
1774 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1775 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1776 </tr>
1777</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1778
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1779<p>Note that the code generator does not yet support large vector types to be
1780 used as function return types. The specific limit on how large a vector
1781 return type codegen can currently handle is target-dependent; currently it's
1782 often a few times longer than a hardware vector register.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1783
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1784</div>
1785
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1786<!-- _______________________________________________________________________ -->
1787<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1788<div class="doc_text">
1789
1790<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1791<p>Opaque types are used to represent unknown types in the system. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1792 corresponds (for example) to the C notion of a forward declared structure
1793 type. In LLVM, opaque types can eventually be resolved to any type (not just
1794 a structure type).</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1795
1796<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1797<pre>
1798 opaque
1799</pre>
1800
1801<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1802<table class="layout">
1803 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1804 <td class="left"><tt>opaque</tt></td>
1805 <td class="left">An opaque type.</td>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1806 </tr>
1807</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1808
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1809</div>
1810
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1811<!-- ======================================================================= -->
1812<div class="doc_subsection">
1813 <a name="t_uprefs">Type Up-references</a>
1814</div>
1815
1816<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1817
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1818<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1819<p>An "up reference" allows you to refer to a lexically enclosing type without
1820 requiring it to have a name. For instance, a structure declaration may
1821 contain a pointer to any of the types it is lexically a member of. Example
1822 of up references (with their equivalent as named type declarations)
1823 include:</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1824
1825<pre>
Chris Lattner3060f5b2009-02-09 10:00:56 +0000[diff] [blame]1826 { \2 * } %x = type { %x* }
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1827 { \2 }* %y = type { %y }*
1828 \1* %z = type %z*
1829</pre>
1830
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1831<p>An up reference is needed by the asmprinter for printing out cyclic types
1832 when there is no declared name for a type in the cycle. Because the
1833 asmprinter does not want to print out an infinite type string, it needs a
1834 syntax to handle recursive types that have no names (all names are optional
1835 in llvm IR).</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1836
1837<h5>Syntax:</h5>
1838<pre>
1839 \&lt;level&gt;
1840</pre>
1841
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1842<p>The level is the count of the lexical type that is being referred to.</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1843
1844<h5>Examples:</h5>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1845<table class="layout">
1846 <tr class="layout">
1847 <td class="left"><tt>\1*</tt></td>
1848 <td class="left">Self-referential pointer.</td>
1849 </tr>
1850 <tr class="layout">
1851 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
1852 <td class="left">Recursive structure where the upref refers to the out-most
1853 structure.</td>
1854 </tr>
1855</table>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1856
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1857</div>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1858
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1859<!-- *********************************************************************** -->
1860<div class="doc_section"> <a name="constants">Constants</a> </div>
1861<!-- *********************************************************************** -->
1862
1863<div class="doc_text">
1864
1865<p>LLVM has several different basic types of constants. This section describes
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1866 them all and their syntax.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1867
1868</div>
1869
1870<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1871<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1872
1873<div class="doc_text">
1874
1875<dl>
1876 <dt><b>Boolean constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1877 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1878 constants of the <tt><a href="#t_primitive">i1</a></tt> type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1879
1880 <dt><b>Integer constants</b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1881 <dd>Standard integers (such as '4') are constants of
1882 the <a href="#t_integer">integer</a> type. Negative numbers may be used
1883 with integer types.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1884
1885 <dt><b>Floating point constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1886 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1887 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
1888 notation (see below). The assembler requires the exact decimal value of a
1889 floating-point constant. For example, the assembler accepts 1.25 but
1890 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1891 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1892
1893 <dt><b>Null pointer constants</b></dt>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1894 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1895 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1896</dl>
1897
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1898<p>The one non-intuitive notation for constants is the hexadecimal form of
1899 floating point constants. For example, the form '<tt>double
1900 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
1901 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
1902 constants are required (and the only time that they are generated by the
1903 disassembler) is when a floating point constant must be emitted but it cannot
1904 be represented as a decimal floating point number in a reasonable number of
1905 digits. For example, NaN's, infinities, and other special values are
1906 represented in their IEEE hexadecimal format so that assembly and disassembly
1907 do not cause any bits to change in the constants.</p>
1908
Dale Johannesenbd5e5a82009-02-11 22:14:51 +0000[diff] [blame]1909<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1910 represented using the 16-digit form shown above (which matches the IEEE754
1911 representation for double); float values must, however, be exactly
1912 representable as IEE754 single precision. Hexadecimal format is always used
1913 for long double, and there are three forms of long double. The 80-bit format
1914 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
1915 The 128-bit format used by PowerPC (two adjacent doubles) is represented
1916 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
1917 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
1918 currently supported target uses this format. Long doubles will only work if
1919 they match the long double format on your target. All hexadecimal formats
1920 are big-endian (sign bit at the left).</p>
1921
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1922</div>
1923
1924<!-- ======================================================================= -->
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]1925<div class="doc_subsection">
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]1926<a name="aggregateconstants"></a> <!-- old anchor -->
1927<a name="complexconstants">Complex Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1928</div>
1929
1930<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1931
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]1932<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1933 constants and smaller complex constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1934
1935<dl>
1936 <dt><b>Structure constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1937 <dd>Structure constants are represented with notation similar to structure
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1938 type definitions (a comma separated list of elements, surrounded by braces
1939 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1940 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
1941 Structure constants must have <a href="#t_struct">structure type</a>, and
1942 the number and types of elements must match those specified by the
1943 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1944
1945 <dt><b>Array constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1946 <dd>Array constants are represented with notation similar to array type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1947 definitions (a comma separated list of elements, surrounded by square
1948 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
1949 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
1950 the number and types of elements must match those specified by the
1951 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1952
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1953 <dt><b>Vector constants</b></dt>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1954 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1955 definitions (a comma separated list of elements, surrounded by
1956 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
1957 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
1958 have <a href="#t_vector">vector type</a>, and the number and types of
1959 elements must match those specified by the type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1960
1961 <dt><b>Zero initialization</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1962 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1963 value to zero of <em>any</em> type, including scalar and aggregate types.
1964 This is often used to avoid having to print large zero initializers
1965 (e.g. for large arrays) and is always exactly equivalent to using explicit
1966 zero initializers.</dd>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]1967
1968 <dt><b>Metadata node</b></dt>
Nick Lewycky1e8c7a62009-05-30 16:08:30 +0000[diff] [blame]1969 <dd>A metadata node is a structure-like constant with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1970 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
1971 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
1972 be interpreted as part of the instruction stream, metadata is a place to
1973 attach additional information such as debug info.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1974</dl>
1975
1976</div>
1977
1978<!-- ======================================================================= -->
1979<div class="doc_subsection">
1980 <a name="globalconstants">Global Variable and Function Addresses</a>
1981</div>
1982
1983<div class="doc_text">
1984
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1985<p>The addresses of <a href="#globalvars">global variables</a>
1986 and <a href="#functionstructure">functions</a> are always implicitly valid
1987 (link-time) constants. These constants are explicitly referenced when
1988 the <a href="#identifiers">identifier for the global</a> is used and always
1989 have <a href="#t_pointer">pointer</a> type. For example, the following is a
1990 legal LLVM file:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1991
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1992<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1993<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]1994@X = global i32 17
1995@Y = global i32 42
1996@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1997</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1998</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1999
2000</div>
2001
2002<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]2003<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2004<div class="doc_text">
2005
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2006<p>The string '<tt>undef</tt>' is recognized as a type-less constant that has no
2007 specific value. Undefined values may be of any type and be used anywhere a
2008 constant is permitted.</p>
2009
2010<p>Undefined values indicate to the compiler that the program is well defined no
2011 matter what value is used, giving the compiler more freedom to optimize.</p>
2012
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2013</div>
2014
2015<!-- ======================================================================= -->
2016<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
2017</div>
2018
2019<div class="doc_text">
2020
2021<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2022 to be used as constants. Constant expressions may be of
2023 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2024 operation that does not have side effects (e.g. load and call are not
2025 supported). The following is the syntax for constant expressions:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2026
2027<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2028 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2029 <dd>Truncate a constant to another type. The bit size of CST must be larger
2030 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2031
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2032 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2033 <dd>Zero extend a constant to another type. The bit size of CST must be
2034 smaller or equal to the bit size of TYPE. Both types must be
2035 integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2036
2037 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2038 <dd>Sign extend a constant to another type. The bit size of CST must be
2039 smaller or equal to the bit size of TYPE. Both types must be
2040 integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2041
2042 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2043 <dd>Truncate a floating point constant to another floating point type. The
2044 size of CST must be larger than the size of TYPE. Both types must be
2045 floating point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2046
2047 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2048 <dd>Floating point extend a constant to another type. The size of CST must be
2049 smaller or equal to the size of TYPE. Both types must be floating
2050 point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2051
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]2052 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2053 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2054 constant. TYPE must be a scalar or vector integer type. CST must be of
2055 scalar or vector floating point type. Both CST and TYPE must be scalars,
2056 or vectors of the same number of elements. If the value won't fit in the
2057 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2058
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2059 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2060 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2061 constant. TYPE must be a scalar or vector integer type. CST must be of
2062 scalar or vector floating point type. Both CST and TYPE must be scalars,
2063 or vectors of the same number of elements. If the value won't fit in the
2064 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2065
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2066 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2067 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2068 constant. TYPE must be a scalar or vector floating point type. CST must be
2069 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2070 vectors of the same number of elements. If the value won't fit in the
2071 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2072
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2073 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2074 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2075 constant. TYPE must be a scalar or vector floating point type. CST must be
2076 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2077 vectors of the same number of elements. If the value won't fit in the
2078 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2079
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2080 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
2081 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2082 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2083 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2084 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2085
2086 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2087 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2088 type. CST must be of integer type. The CST value is zero extended,
2089 truncated, or unchanged to make it fit in a pointer size. This one is
2090 <i>really</i> dangerous!</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2091
2092 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner03bbad62009-02-28 18:27:03 +0000[diff] [blame]2093 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2094 are the same as those for the <a href="#i_bitcast">bitcast
2095 instruction</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2096
2097 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]2098 <dt><b><tt>getelementptr inbounds ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2099 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2100 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2101 instruction, the index list may have zero or more indexes, which are
2102 required to make sense for the type of "CSTPTR".</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2103
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2104 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2105 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2106
2107 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
2108 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2109
2110 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
2111 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2112
2113 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2114 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2115 constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2116
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]2117 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2118 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2119 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2120
2121 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2122 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2123 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2124
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2125 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2126 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2127 be any of the <a href="#binaryops">binary</a>
2128 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2129 on operands are the same as those for the corresponding instruction
2130 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2131</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2132
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2133</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]2134
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2135<!-- ======================================================================= -->
2136<div class="doc_subsection"><a name="metadata">Embedded Metadata</a>
2137</div>
2138
2139<div class="doc_text">
2140
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2141<p>Embedded metadata provides a way to attach arbitrary data to the instruction
2142 stream without affecting the behaviour of the program. There are two
2143 metadata primitives, strings and nodes. All metadata has the
2144 <tt>metadata</tt> type and is identified in syntax by a preceding exclamation
2145 point ('<tt>!</tt>').</p>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2146
2147<p>A metadata string is a string surrounded by double quotes. It can contain
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2148 any character by escaping non-printable characters with "\xx" where "xx" is
2149 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2150
2151<p>Metadata nodes are represented with notation similar to structure constants
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2152 (a comma separated list of elements, surrounded by braces and preceeded by an
2153 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2154 10}</tt>".</p>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2155
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2156<p>A metadata node will attempt to track changes to the values it holds. In the
2157 event that a value is deleted, it will be replaced with a typeless
2158 "<tt>null</tt>", such as "<tt>metadata !{null, i32 10}</tt>".</p>
Nick Lewyckycb337992009-05-10 20:57:05 +0000[diff] [blame]2159
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2160<p>Optimizations may rely on metadata to provide additional information about
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2161 the program that isn't available in the instructions, or that isn't easily
2162 computable. Similarly, the code generator may expect a certain metadata
2163 format to be used to express debugging information.</p>
2164
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2165</div>
2166
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2167<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2168<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
2169<!-- *********************************************************************** -->
2170
2171<!-- ======================================================================= -->
2172<div class="doc_subsection">
2173<a name="inlineasm">Inline Assembler Expressions</a>
2174</div>
2175
2176<div class="doc_text">
2177
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2178<p>LLVM supports inline assembler expressions (as opposed
2179 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2180 a special value. This value represents the inline assembler as a string
2181 (containing the instructions to emit), a list of operand constraints (stored
2182 as a string), and a flag that indicates whether or not the inline asm
2183 expression has side effects. An example inline assembler expression is:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2184
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2185<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2186<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2187i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2188</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2189</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2190
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2191<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2192 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2193 have:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2194
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2195<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2196<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2197%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]2198</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2199</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2200
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2201<p>Inline asms with side effects not visible in the constraint list must be
2202 marked as having side effects. This is done through the use of the
2203 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2204
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2205<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2206<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2207call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2208</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2209</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2210
2211<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2212 documented here. Constraints on what can be done (e.g. duplication, moving,
2213 etc need to be documented). This is probably best done by reference to
2214 another document that covers inline asm from a holistic perspective.</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2215
2216</div>
2217
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2218
2219<!-- *********************************************************************** -->
2220<div class="doc_section">
2221 <a name="intrinsic_globals">Intrinsic Global Variables</a>
2222</div>
2223<!-- *********************************************************************** -->
2224
2225<p>LLVM has a number of "magic" global variables that contain data that affect
2226code generation or other IR semantics. These are documented here. All globals
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2227of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2228section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2229by LLVM.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2230
2231<!-- ======================================================================= -->
2232<div class="doc_subsection">
2233<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
2234</div>
2235
2236<div class="doc_text">
2237
2238<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2239href="#linkage_appending">appending linkage</a>. This array contains a list of
2240pointers to global variables and functions which may optionally have a pointer
2241cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2242
2243<pre>
2244 @X = global i8 4
2245 @Y = global i32 123
2246
2247 @llvm.used = appending global [2 x i8*] [
2248 i8* @X,
2249 i8* bitcast (i32* @Y to i8*)
2250 ], section "llvm.metadata"
2251</pre>
2252
2253<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2254compiler, assembler, and linker are required to treat the symbol as if there is
2255a reference to the global that it cannot see. For example, if a variable has
2256internal linkage and no references other than that from the <tt>@llvm.used</tt>
2257list, it cannot be deleted. This is commonly used to represent references from
2258inline asms and other things the compiler cannot "see", and corresponds to
2259"attribute((used))" in GNU C.</p>
2260
2261<p>On some targets, the code generator must emit a directive to the assembler or
2262object file to prevent the assembler and linker from molesting the symbol.</p>
2263
2264</div>
2265
2266<!-- ======================================================================= -->
2267<div class="doc_subsection">
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2268<a name="intg_compiler_used">The '<tt>llvm.compiler.used</tt>' Global Variable</a>
2269</div>
2270
2271<div class="doc_text">
2272
2273<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2274<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2275touching the symbol. On targets that support it, this allows an intelligent
2276linker to optimize references to the symbol without being impeded as it would be
2277by <tt>@llvm.used</tt>.</p>
2278
2279<p>This is a rare construct that should only be used in rare circumstances, and
2280should not be exposed to source languages.</p>
2281
2282</div>
2283
2284<!-- ======================================================================= -->
2285<div class="doc_subsection">
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2286<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
2287</div>
2288
2289<div class="doc_text">
2290
2291<p>TODO: Describe this.</p>
2292
2293</div>
2294
2295<!-- ======================================================================= -->
2296<div class="doc_subsection">
2297<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
2298</div>
2299
2300<div class="doc_text">
2301
2302<p>TODO: Describe this.</p>
2303
2304</div>
2305
2306
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2307<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2308<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
2309<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2310
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2311<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2312
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2313<p>The LLVM instruction set consists of several different classifications of
2314 instructions: <a href="#terminators">terminator
2315 instructions</a>, <a href="#binaryops">binary instructions</a>,
2316 <a href="#bitwiseops">bitwise binary instructions</a>,
2317 <a href="#memoryops">memory instructions</a>, and
2318 <a href="#otherops">other instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2319
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2320</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2321
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2322<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2323<div class="doc_subsection"> <a name="terminators">Terminator
2324Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2325
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2326<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2327
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2328<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2329 in a program ends with a "Terminator" instruction, which indicates which
2330 block should be executed after the current block is finished. These
2331 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2332 control flow, not values (the one exception being the
2333 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2334
2335<p>There are six different terminator instructions: the
2336 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2337 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2338 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
2339 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2340 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2341 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2342
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2343</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2344
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2345<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2346<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
2347Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2348
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2349<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2350
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2351<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2352<pre>
2353 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]2354 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2355</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2356
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2357<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2358<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2359 a value) from a function back to the caller.</p>
2360
2361<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2362 value and then causes control flow, and one that just causes control flow to
2363 occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2364
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2365<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2366<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2367 return value. The type of the return value must be a
2368 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2369
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2370<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2371 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2372 value or a return value with a type that does not match its type, or if it
2373 has a void return type and contains a '<tt>ret</tt>' instruction with a
2374 return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2375
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2376<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2377<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2378 the calling function's context. If the caller is a
2379 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2380 instruction after the call. If the caller was an
2381 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2382 the beginning of the "normal" destination block. If the instruction returns
2383 a value, that value shall set the call or invoke instruction's return
2384 value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2385
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2386<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2387<pre>
2388 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2389 ret void <i>; Return from a void function</i>
Bill Wendling0a4bbbf2009-02-28 22:12:54 +0000[diff] [blame]2390 ret { i32, i8 } { i32 4, i8 2 } <i>; Return a struct of values 4 and 2</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2391</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2392
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]2393<p>Note that the code generator does not yet fully support large
2394 return values. The specific sizes that are currently supported are
2395 dependent on the target. For integers, on 32-bit targets the limit
2396 is often 64 bits, and on 64-bit targets the limit is often 128 bits.
2397 For aggregate types, the current limits are dependent on the element
2398 types; for example targets are often limited to 2 total integer
2399 elements and 2 total floating-point elements.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2400
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2401</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2402<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2403<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2404
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2405<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2406
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2407<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2408<pre>
2409 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]2410</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2411
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2412<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2413<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
2414 different basic block in the current function. There are two forms of this
2415 instruction, corresponding to a conditional branch and an unconditional
2416 branch.</p>
2417
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2418<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2419<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
2420 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
2421 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
2422 target.</p>
2423
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2424<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2425<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2426 argument is evaluated. If the value is <tt>true</tt>, control flows to the
2427 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2428 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
2429
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2430<h5>Example:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2431<pre>
2432Test:
2433 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
2434 br i1 %cond, label %IfEqual, label %IfUnequal
2435IfEqual:
2436 <a href="#i_ret">ret</a> i32 1
2437IfUnequal:
2438 <a href="#i_ret">ret</a> i32 0
2439</pre>
2440
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2441</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2442
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2443<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2444<div class="doc_subsubsection">
2445 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2446</div>
2447
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2448<div class="doc_text">
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2449
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2450<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2451<pre>
2452 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2453</pre>
2454
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2455<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2456<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2457 several different places. It is a generalization of the '<tt>br</tt>'
2458 instruction, allowing a branch to occur to one of many possible
2459 destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2460
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2461<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2462<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2463 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
2464 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
2465 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2466
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2467<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2468<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2469 destinations. When the '<tt>switch</tt>' instruction is executed, this table
2470 is searched for the given value. If the value is found, control flow is
2471 transfered to the corresponding destination; otherwise, control flow is
2472 transfered to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2473
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2474<h5>Implementation:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2475<p>Depending on properties of the target machine and the particular
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2476 <tt>switch</tt> instruction, this instruction may be code generated in
2477 different ways. For example, it could be generated as a series of chained
2478 conditional branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2479
2480<h5>Example:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2481<pre>
2482 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2483 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2484 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2485
2486 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2487 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2488
2489 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2490 switch i32 %val, label %otherwise [ i32 0, label %onzero
2491 i32 1, label %onone
2492 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2493</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2494
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2495</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2496
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2497<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2498<div class="doc_subsubsection">
2499 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2500</div>
2501
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2502<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2503
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2504<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2505<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2506 &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]2507 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2508</pre>
2509
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2510<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2511<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2512 function, with the possibility of control flow transfer to either the
2513 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
2514 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
2515 control flow will return to the "normal" label. If the callee (or any
2516 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
2517 instruction, control is interrupted and continued at the dynamically nearest
2518 "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2519
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2520<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2521<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2522
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2523<ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2524 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
2525 convention</a> the call should use. If none is specified, the call
2526 defaults to using C calling conventions.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2527
2528 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2529 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
2530 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2531
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2532 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2533 function value being invoked. In most cases, this is a direct function
2534 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
2535 off an arbitrary pointer to function value.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2536
2537 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2538 function to be invoked. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2539
2540 <li>'<tt>function args</tt>': argument list whose types match the function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2541 signature argument types. If the function signature indicates the
2542 function accepts a variable number of arguments, the extra arguments can
2543 be specified.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2544
2545 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2546 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2547
2548 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2549 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2550
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2551 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2552 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2553 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2554</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2555
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2556<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2557<p>This instruction is designed to operate as a standard
2558 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
2559 primary difference is that it establishes an association with a label, which
2560 is used by the runtime library to unwind the stack.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2561
2562<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2563 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2564 exception. Additionally, this is important for implementation of
2565 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2566
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2567<p>For the purposes of the SSA form, the definition of the value returned by the
2568 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
2569 block to the "normal" label. If the callee unwinds then no return value is
2570 available.</p>
Dan Gohmanf96a4992009-05-22 21:47:08 +0000[diff] [blame]2571
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2572<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2573<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2574 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2575 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2576 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2577 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2578</pre>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2579
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2580</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2581
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2582<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2583
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2584<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2585Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2586
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2587<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2588
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2589<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2590<pre>
2591 unwind
2592</pre>
2593
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2594<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2595<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2596 at the first callee in the dynamic call stack which used
2597 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
2598 This is primarily used to implement exception handling.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2599
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2600<h5>Semantics:</h5>
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]2601<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2602 immediately halt. The dynamic call stack is then searched for the
2603 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
2604 Once found, execution continues at the "exceptional" destination block
2605 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
2606 instruction in the dynamic call chain, undefined behavior results.</p>
2607
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2608</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2609
2610<!-- _______________________________________________________________________ -->
2611
2612<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2613Instruction</a> </div>
2614
2615<div class="doc_text">
2616
2617<h5>Syntax:</h5>
2618<pre>
2619 unreachable
2620</pre>
2621
2622<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2623<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2624 instruction is used to inform the optimizer that a particular portion of the
2625 code is not reachable. This can be used to indicate that the code after a
2626 no-return function cannot be reached, and other facts.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2627
2628<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2629<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2630
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2631</div>
2632
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2633<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2634<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2635
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2636<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2637
2638<p>Binary operators are used to do most of the computation in a program. They
2639 require two operands of the same type, execute an operation on them, and
2640 produce a single value. The operands might represent multiple data, as is
2641 the case with the <a href="#t_vector">vector</a> data type. The result value
2642 has the same type as its operands.</p>
2643
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2644<p>There are several different binary operators:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2645
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2646</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2647
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2648<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2649<div class="doc_subsubsection">
2650 <a name="i_add">'<tt>add</tt>' Instruction</a>
2651</div>
2652
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2653<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2654
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2655<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2656<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2657 &lt;result&gt; = add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]2658 &lt;result&gt; = nuw add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2659 &lt;result&gt; = nsw add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2660 &lt;result&gt; = nuw nsw 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]2661</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2662
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2663<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2664<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2665
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2666<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2667<p>The two arguments to the '<tt>add</tt>' instruction must
2668 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2669 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2670
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2671<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2672<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2673
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2674<p>If the sum has unsigned overflow, the result returned is the mathematical
2675 result modulo 2<sup>n</sup>, where n is the bit width of the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2676
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2677<p>Because LLVM integers use a two's complement representation, this instruction
2678 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2679
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]2680<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2681 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2682 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
2683 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2684
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2685<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2686<pre>
2687 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2688</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2689
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2690</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2691
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2692<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2693<div class="doc_subsubsection">
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2694 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
2695</div>
2696
2697<div class="doc_text">
2698
2699<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2700<pre>
2701 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2702</pre>
2703
2704<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2705<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
2706
2707<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2708<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2709 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2710 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2711
2712<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2713<p>The value produced is the floating point sum of the two operands.</p>
2714
2715<h5>Example:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2716<pre>
2717 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
2718</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2719
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2720</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2721
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2722<!-- _______________________________________________________________________ -->
2723<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2724 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2725</div>
2726
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2727<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2728
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2729<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2730<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]2731 &lt;result&gt; = sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2732 &lt;result&gt; = nuw sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2733 &lt;result&gt; = nsw sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2734 &lt;result&gt; = nuw nsw 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]2735</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2736
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2737<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2738<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2739 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2740
2741<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2742 '<tt>neg</tt>' instruction present in most other intermediate
2743 representations.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2744
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2745<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2746<p>The two arguments to the '<tt>sub</tt>' instruction must
2747 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2748 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2749
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2750<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2751<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2752
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2753<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2754 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
2755 result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2756
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2757<p>Because LLVM integers use a two's complement representation, this instruction
2758 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2759
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]2760<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2761 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2762 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
2763 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2764
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2765<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2766<pre>
2767 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2768 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2769</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2770
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2771</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2772
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2773<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2774<div class="doc_subsubsection">
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2775 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
2776</div>
2777
2778<div class="doc_text">
2779
2780<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2781<pre>
2782 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2783</pre>
2784
2785<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2786<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2787 operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2788
2789<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2790 '<tt>fneg</tt>' instruction present in most other intermediate
2791 representations.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2792
2793<h5>Arguments:</h5>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]2794<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2795 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2796 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2797
2798<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2799<p>The value produced is the floating point difference of the two operands.</p>
2800
2801<h5>Example:</h5>
2802<pre>
2803 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
2804 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
2805</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2806
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2807</div>
2808
2809<!-- _______________________________________________________________________ -->
2810<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2811 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2812</div>
2813
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2814<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2815
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2816<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2817<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]2818 &lt;result&gt; = mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2819 &lt;result&gt; = nuw mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2820 &lt;result&gt; = nsw mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2821 &lt;result&gt; = nuw nsw 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]2822</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2823
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2824<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2825<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2826
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2827<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2828<p>The two arguments to the '<tt>mul</tt>' instruction must
2829 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2830 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2831
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2832<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2833<p>The value produced is the integer product of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2834
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2835<p>If the result of the multiplication has unsigned overflow, the result
2836 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
2837 width of the result.</p>
2838
2839<p>Because LLVM integers use a two's complement representation, and the result
2840 is the same width as the operands, this instruction returns the correct
2841 result for both signed and unsigned integers. If a full product
2842 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
2843 be sign-extended or zero-extended as appropriate to the width of the full
2844 product.</p>
2845
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]2846<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2847 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2848 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
2849 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2850
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2851<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2852<pre>
2853 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2854</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2855
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2856</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2857
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2858<!-- _______________________________________________________________________ -->
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2859<div class="doc_subsubsection">
2860 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
2861</div>
2862
2863<div class="doc_text">
2864
2865<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2866<pre>
2867 &lt;result&gt; = fmul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2868</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2869
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2870<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2871<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2872
2873<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2874<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2875 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2876 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2877
2878<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2879<p>The value produced is the floating point product of the two operands.</p>
2880
2881<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2882<pre>
2883 &lt;result&gt; = fmul float 4.0, %var <i>; yields {float}:result = 4.0 * %var</i>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2884</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2885
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2886</div>
2887
2888<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2889<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2890</a></div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2891
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2892<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2893
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2894<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2895<pre>
2896 &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]2897</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2898
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2899<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2900<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2901
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2902<h5>Arguments:</h5>
2903<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2904 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2905 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2906
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2907<h5>Semantics:</h5>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2908<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2909
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2910<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2911 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2912
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2913<p>Division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2914
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2915<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2916<pre>
2917 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2918</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2919
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2920</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2921
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2922<!-- _______________________________________________________________________ -->
2923<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2924</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2925
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2926<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2927
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2928<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2929<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2930 &lt;result&gt; = sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2931 &lt;result&gt; = exact 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]2932</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2933
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2934<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2935<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2936
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2937<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2938<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2939 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2940 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2941
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2942<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2943<p>The value produced is the signed integer quotient of the two operands rounded
2944 towards zero.</p>
2945
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2946<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2947 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2948
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2949<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2950 undefined behavior; this is a rare case, but can occur, for example, by doing
2951 a 32-bit division of -2147483648 by -1.</p>
2952
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame]2953<p>If the <tt>exact</tt> keyword is present, the result value of the
2954 <tt>sdiv</tt> is undefined if the result would be rounded or if overflow
2955 would occur.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2956
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2957<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2958<pre>
2959 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2960</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2961
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2962</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2963
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2964<!-- _______________________________________________________________________ -->
2965<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2966Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2967
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2968<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2969
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2970<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2971<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2972 &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]2973</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2974
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2975<h5>Overview:</h5>
2976<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2977
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2978<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2979<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2980 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2981 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2982
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2983<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2984<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2985
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2986<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2987<pre>
2988 &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]2989</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2990
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2991</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2992
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2993<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2994<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2995</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2996
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2997<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2998
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2999<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3000<pre>
3001 &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]3002</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3003
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3004<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3005<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3006 division of its two arguments.</p>
3007
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3008<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3009<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3010 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3011 values. Both arguments must have identical types.</p>
3012
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3013<h5>Semantics:</h5>
3014<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3015 This instruction always performs an unsigned division to get the
3016 remainder.</p>
3017
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3018<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3019 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3020
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3021<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3022
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3023<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3024<pre>
3025 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3026</pre>
3027
3028</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3029
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3030<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3031<div class="doc_subsubsection">
3032 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
3033</div>
3034
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3035<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3036
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3037<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3038<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3039 &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]3040</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3041
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3042<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3043<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3044 division of its two operands. This instruction can also take
3045 <a href="#t_vector">vector</a> versions of the values in which case the
3046 elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]3047
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3048<h5>Arguments:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3049<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3050 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3051 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3052
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3053<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3054<p>This instruction returns the <i>remainder</i> of a division (where the result
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3055 has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
3056 operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
3057 a value. For more information about the difference,
3058 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3059 Math Forum</a>. For a table of how this is implemented in various languages,
3060 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3061 Wikipedia: modulo operation</a>.</p>
3062
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3063<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3064 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3065
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3066<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3067 Overflow also leads to undefined behavior; this is a rare case, but can
3068 occur, for example, by taking the remainder of a 32-bit division of
3069 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3070 lets srem be implemented using instructions that return both the result of
3071 the division and the remainder.)</p>
3072
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3073<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3074<pre>
3075 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3076</pre>
3077
3078</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3079
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3080<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3081<div class="doc_subsubsection">
3082 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
3083
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3084<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3085
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3086<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3087<pre>
3088 &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]3089</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3090
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3091<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3092<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3093 its two operands.</p>
3094
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3095<h5>Arguments:</h5>
3096<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3097 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3098 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3099
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3100<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3101<p>This instruction returns the <i>remainder</i> of a division. The remainder
3102 has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3103
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3104<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3105<pre>
3106 &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]3107</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3108
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3109</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]3110
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3111<!-- ======================================================================= -->
3112<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
3113Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3114
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3115<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3116
3117<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3118 program. They are generally very efficient instructions and can commonly be
3119 strength reduced from other instructions. They require two operands of the
3120 same type, execute an operation on them, and produce a single value. The
3121 resulting value is the same type as its operands.</p>
3122
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3123</div>
3124
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3125<!-- _______________________________________________________________________ -->
3126<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
3127Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3128
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3129<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3130
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3131<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3132<pre>
3133 &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]3134</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3135
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3136<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3137<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3138 a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3139
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3140<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3141<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3142 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3143 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3144
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3145<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3146<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3147 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3148 is (statically or dynamically) negative or equal to or larger than the number
3149 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3150 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3151 shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3152
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3153<h5>Example:</h5>
3154<pre>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3155 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3156 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3157 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3158 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3159 &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]3160</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3161
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3162</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3163
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3164<!-- _______________________________________________________________________ -->
3165<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
3166Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3167
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3168<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3169
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3170<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3171<pre>
3172 &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]3173</pre>
3174
3175<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3176<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3177 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3178
3179<h5>Arguments:</h5>
3180<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3181 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3182 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3183
3184<h5>Semantics:</h5>
3185<p>This instruction always performs a logical shift right operation. The most
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3186 significant bits of the result will be filled with zero bits after the shift.
3187 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3188 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3189 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3190 shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3191
3192<h5>Example:</h5>
3193<pre>
3194 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3195 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3196 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3197 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3198 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3199 &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]3200</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3201
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3202</div>
3203
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3204<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3205<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
3206Instruction</a> </div>
3207<div class="doc_text">
3208
3209<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3210<pre>
3211 &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]3212</pre>
3213
3214<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3215<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3216 operand shifted to the right a specified number of bits with sign
3217 extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3218
3219<h5>Arguments:</h5>
3220<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3221 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3222 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3223
3224<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3225<p>This instruction always performs an arithmetic shift right operation, The
3226 most significant bits of the result will be filled with the sign bit
3227 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3228 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3229 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3230 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3231
3232<h5>Example:</h5>
3233<pre>
3234 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3235 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3236 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3237 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3238 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3239 &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]3240</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3241
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3242</div>
3243
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3244<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3245<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
3246Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3247
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3248<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3249
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3250<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3251<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3252 &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]3253</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3254
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3255<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3256<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3257 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3258
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3259<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3260<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3261 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3262 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3263
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3264<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3265<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3266
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3267<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3268 <tbody>
3269 <tr>
3270 <td>In0</td>
3271 <td>In1</td>
3272 <td>Out</td>
3273 </tr>
3274 <tr>
3275 <td>0</td>
3276 <td>0</td>
3277 <td>0</td>
3278 </tr>
3279 <tr>
3280 <td>0</td>
3281 <td>1</td>
3282 <td>0</td>
3283 </tr>
3284 <tr>
3285 <td>1</td>
3286 <td>0</td>
3287 <td>0</td>
3288 </tr>
3289 <tr>
3290 <td>1</td>
3291 <td>1</td>
3292 <td>1</td>
3293 </tr>
3294 </tbody>
3295</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3296
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3297<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3298<pre>
3299 &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]3300 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3301 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3302</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3303</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3304<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3305<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3306
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3307<div class="doc_text">
3308
3309<h5>Syntax:</h5>
3310<pre>
3311 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3312</pre>
3313
3314<h5>Overview:</h5>
3315<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
3316 two operands.</p>
3317
3318<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3319<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3320 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3321 values. Both arguments must have identical types.</p>
3322
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3323<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3324<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3325
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3326<table border="1" cellspacing="0" cellpadding="4">
3327 <tbody>
3328 <tr>
3329 <td>In0</td>
3330 <td>In1</td>
3331 <td>Out</td>
3332 </tr>
3333 <tr>
3334 <td>0</td>
3335 <td>0</td>
3336 <td>0</td>
3337 </tr>
3338 <tr>
3339 <td>0</td>
3340 <td>1</td>
3341 <td>1</td>
3342 </tr>
3343 <tr>
3344 <td>1</td>
3345 <td>0</td>
3346 <td>1</td>
3347 </tr>
3348 <tr>
3349 <td>1</td>
3350 <td>1</td>
3351 <td>1</td>
3352 </tr>
3353 </tbody>
3354</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3355
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3356<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3357<pre>
3358 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3359 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
3360 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3361</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3362
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3363</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3364
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3365<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3366<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
3367Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3368
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3369<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3370
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3371<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3372<pre>
3373 &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]3374</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3375
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3376<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3377<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
3378 its two operands. The <tt>xor</tt> is used to implement the "one's
3379 complement" operation, which is the "~" operator in C.</p>
3380
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3381<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3382<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3383 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3384 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3385
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3386<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3387<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3388
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3389<table border="1" cellspacing="0" cellpadding="4">
3390 <tbody>
3391 <tr>
3392 <td>In0</td>
3393 <td>In1</td>
3394 <td>Out</td>
3395 </tr>
3396 <tr>
3397 <td>0</td>
3398 <td>0</td>
3399 <td>0</td>
3400 </tr>
3401 <tr>
3402 <td>0</td>
3403 <td>1</td>
3404 <td>1</td>
3405 </tr>
3406 <tr>
3407 <td>1</td>
3408 <td>0</td>
3409 <td>1</td>
3410 </tr>
3411 <tr>
3412 <td>1</td>
3413 <td>1</td>
3414 <td>0</td>
3415 </tr>
3416 </tbody>
3417</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3418
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3419<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3420<pre>
3421 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3422 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
3423 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
3424 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3425</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3426
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3427</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3428
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3429<!-- ======================================================================= -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3430<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3431 <a name="vectorops">Vector Operations</a>
3432</div>
3433
3434<div class="doc_text">
3435
3436<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3437 target-independent manner. These instructions cover the element-access and
3438 vector-specific operations needed to process vectors effectively. While LLVM
3439 does directly support these vector operations, many sophisticated algorithms
3440 will want to use target-specific intrinsics to take full advantage of a
3441 specific target.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3442
3443</div>
3444
3445<!-- _______________________________________________________________________ -->
3446<div class="doc_subsubsection">
3447 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
3448</div>
3449
3450<div class="doc_text">
3451
3452<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3453<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3454 &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]3455</pre>
3456
3457<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3458<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
3459 from a vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3460
3461
3462<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3463<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
3464 of <a href="#t_vector">vector</a> type. The second operand is an index
3465 indicating the position from which to extract the element. The index may be
3466 a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3467
3468<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3469<p>The result is a scalar of the same type as the element type of
3470 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
3471 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3472 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3473
3474<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3475<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3476 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3477</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3478
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3479</div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3480
3481<!-- _______________________________________________________________________ -->
3482<div class="doc_subsubsection">
3483 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
3484</div>
3485
3486<div class="doc_text">
3487
3488<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3489<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]3490 &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]3491</pre>
3492
3493<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3494<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
3495 vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3496
3497<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3498<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
3499 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
3500 whose type must equal the element type of the first operand. The third
3501 operand is an index indicating the position at which to insert the value.
3502 The index may be a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3503
3504<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3505<p>The result is a vector of the same type as <tt>val</tt>. Its element values
3506 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
3507 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3508 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3509
3510<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3511<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3512 %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]3513</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3514
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3515</div>
3516
3517<!-- _______________________________________________________________________ -->
3518<div class="doc_subsubsection">
3519 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3520</div>
3521
3522<div class="doc_text">
3523
3524<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3525<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3526 &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]3527</pre>
3528
3529<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3530<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
3531 from two input vectors, returning a vector with the same element type as the
3532 input and length that is the same as the shuffle mask.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3533
3534<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3535<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
3536 with types that match each other. The third argument is a shuffle mask whose
3537 element type is always 'i32'. The result of the instruction is a vector
3538 whose length is the same as the shuffle mask and whose element type is the
3539 same as the element type of the first two operands.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3540
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3541<p>The shuffle mask operand is required to be a constant vector with either
3542 constant integer or undef values.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3543
3544<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3545<p>The elements of the two input vectors are numbered from left to right across
3546 both of the vectors. The shuffle mask operand specifies, for each element of
3547 the result vector, which element of the two input vectors the result element
3548 gets. The element selector may be undef (meaning "don't care") and the
3549 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3550
3551<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3552<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3553 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3554 &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]3555 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
3556 &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]3557 %result = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
3558 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
3559 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
3560 &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]3561</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3562
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3563</div>
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]3564
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3565<!-- ======================================================================= -->
3566<div class="doc_subsection">
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3567 <a name="aggregateops">Aggregate Operations</a>
3568</div>
3569
3570<div class="doc_text">
3571
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3572<p>LLVM supports several instructions for working with aggregate values.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3573
3574</div>
3575
3576<!-- _______________________________________________________________________ -->
3577<div class="doc_subsubsection">
3578 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3579</div>
3580
3581<div class="doc_text">
3582
3583<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3584<pre>
3585 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3586</pre>
3587
3588<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3589<p>The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3590 or array element from an aggregate value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3591
3592<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3593<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
3594 of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type. The
3595 operands are constant indices to specify which value to extract in a similar
3596 manner as indices in a
3597 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3598
3599<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3600<p>The result is the value at the position in the aggregate specified by the
3601 index operands.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3602
3603<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3604<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3605 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3606</pre>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3607
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3608</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3609
3610<!-- _______________________________________________________________________ -->
3611<div class="doc_subsubsection">
3612 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3613</div>
3614
3615<div class="doc_text">
3616
3617<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3618<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3619 &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]3620</pre>
3621
3622<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3623<p>The '<tt>insertvalue</tt>' instruction inserts a value into a struct field or
3624 array element in an aggregate.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3625
3626
3627<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3628<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
3629 of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type. The
3630 second operand is a first-class value to insert. The following operands are
3631 constant indices indicating the position at which to insert the value in a
3632 similar manner as indices in a
3633 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction. The
3634 value to insert must have the same type as the value identified by the
3635 indices.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3636
3637<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3638<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
3639 that of <tt>val</tt> except that the value at the position specified by the
3640 indices is that of <tt>elt</tt>.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3641
3642<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3643<pre>
Dan Gohman52bb2db2008-06-23 15:26:37 +0000[diff] [blame]3644 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3645</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3646
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3647</div>
3648
3649
3650<!-- ======================================================================= -->
3651<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3652 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3653</div>
3654
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3655<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3656
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3657<p>A key design point of an SSA-based representation is how it represents
3658 memory. In LLVM, no memory locations are in SSA form, which makes things
3659 very simple. This section describes how to read, write, allocate, and free
3660 memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3661
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3662</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3663
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3664<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3665<div class="doc_subsubsection">
3666 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3667</div>
3668
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3669<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3670
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3671<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3672<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3673 &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]3674</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3675
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3676<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3677<p>The '<tt>malloc</tt>' instruction allocates memory from the system heap and
3678 returns a pointer to it. The object is always allocated in the generic
3679 address space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3680
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3681<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3682<p>The '<tt>malloc</tt>' instruction allocates
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3683 <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory from the operating
3684 system and returns a pointer of the appropriate type to the program. If
3685 "NumElements" is specified, it is the number of elements allocated, otherwise
3686 "NumElements" is defaulted to be one. If a constant alignment is specified,
3687 the value result of the allocation is guaranteed to be aligned to at least
3688 that boundary. If not specified, or if zero, the target can choose to align
3689 the allocation on any convenient boundary compatible with the type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3690
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3691<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3692
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3693<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3694<p>Memory is allocated using the system "<tt>malloc</tt>" function, and a
3695 pointer is returned. The result of a zero byte allocation is undefined. The
3696 result is null if there is insufficient memory available.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3697
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3698<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3699<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3700 %array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3701
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3702 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3703 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3704 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3705 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3706 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3707</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]3708
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3709<p>Note that the code generator does not yet respect the alignment value.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]3710
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3711</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3712
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3713<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3714<div class="doc_subsubsection">
3715 <a name="i_free">'<tt>free</tt>' Instruction</a>
3716</div>
3717
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3718<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3719
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3720<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3721<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3722 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3723</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3724
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3725<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3726<p>The '<tt>free</tt>' instruction returns memory back to the unused memory heap
3727 to be reallocated in the future.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3728
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3729<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3730<p>'<tt>value</tt>' shall be a pointer value that points to a value that was
3731 allocated with the '<tt><a href="#i_malloc">malloc</a></tt>' instruction.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3732
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3733<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3734<p>Access to the memory pointed to by the pointer is no longer defined after
3735 this instruction executes. If the pointer is null, the operation is a
3736 noop.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3737
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3738<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3739<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3740 %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]3741 free [4 x i8]* %array
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3742</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3743
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3744</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3745
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3746<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3747<div class="doc_subsubsection">
3748 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3749</div>
3750
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3751<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3752
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3753<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3754<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3755 &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]3756</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3757
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3758<h5>Overview:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3759<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3760 currently executing function, to be automatically released when this function
3761 returns to its caller. The object is always allocated in the generic address
3762 space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3763
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3764<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3765<p>The '<tt>alloca</tt>' instruction
3766 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
3767 runtime stack, returning a pointer of the appropriate type to the program.
3768 If "NumElements" is specified, it is the number of elements allocated,
3769 otherwise "NumElements" is defaulted to be one. If a constant alignment is
3770 specified, the value result of the allocation is guaranteed to be aligned to
3771 at least that boundary. If not specified, or if zero, the target can choose
3772 to align the allocation on any convenient boundary compatible with the
3773 type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3774
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3775<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3776
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3777<h5>Semantics:</h5>
Bill Wendling871eb0a2009-05-08 20:49:29 +0000[diff] [blame]3778<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3779 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
3780 memory is automatically released when the function returns. The
3781 '<tt>alloca</tt>' instruction is commonly used to represent automatic
3782 variables that must have an address available. When the function returns
3783 (either with the <tt><a href="#i_ret">ret</a></tt>
3784 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
3785 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3786
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3787<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3788<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3789 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
3790 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3791 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
3792 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3793</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3794
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3795</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3796
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3797<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3798<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3799Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3800
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3801<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3802
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3803<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3804<pre>
3805 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]
3806 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]
3807</pre>
3808
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3809<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3810<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3811
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3812<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3813<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
3814 from which to load. The pointer must point to
3815 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
3816 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
3817 number or order of execution of this <tt>load</tt> with other
3818 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3819 instructions. </p>
3820
3821<p>The optional constant "align" argument specifies the alignment of the
3822 operation (that is, the alignment of the memory address). A value of 0 or an
3823 omitted "align" argument means that the operation has the preferential
3824 alignment for the target. It is the responsibility of the code emitter to
3825 ensure that the alignment information is correct. Overestimating the
3826 alignment results in an undefined behavior. Underestimating the alignment may
3827 produce less efficient code. An alignment of 1 is always safe.</p>
3828
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3829<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3830<p>The location of memory pointed to is loaded. If the value being loaded is of
3831 scalar type then the number of bytes read does not exceed the minimum number
3832 of bytes needed to hold all bits of the type. For example, loading an
3833 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
3834 <tt>i20</tt> with a size that is not an integral number of bytes, the result
3835 is undefined if the value was not originally written using a store of the
3836 same type.</p>
3837
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3838<h5>Examples:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3839<pre>
3840 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
3841 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3842 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3843</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3844
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3845</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3846
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3847<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3848<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3849Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3850
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]3851<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3852
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3853<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3854<pre>
3855 store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]3856 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]3857</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3858
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3859<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3860<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3861
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3862<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3863<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
3864 and an address at which to store it. The type of the
3865 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
3866 the <a href="#t_firstclass">first class</a> type of the
3867 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked
3868 as <tt>volatile</tt>, then the optimizer is not allowed to modify the number
3869 or order of execution of this <tt>store</tt> with other
3870 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3871 instructions.</p>
3872
3873<p>The optional constant "align" argument specifies the alignment of the
3874 operation (that is, the alignment of the memory address). A value of 0 or an
3875 omitted "align" argument means that the operation has the preferential
3876 alignment for the target. It is the responsibility of the code emitter to
3877 ensure that the alignment information is correct. Overestimating the
3878 alignment results in an undefined behavior. Underestimating the alignment may
3879 produce less efficient code. An alignment of 1 is always safe.</p>
3880
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3881<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3882<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
3883 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
3884 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
3885 does not exceed the minimum number of bytes needed to hold all bits of the
3886 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
3887 writing a value of a type like <tt>i20</tt> with a size that is not an
3888 integral number of bytes, it is unspecified what happens to the extra bits
3889 that do not belong to the type, but they will typically be overwritten.</p>
3890
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3891<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3892<pre>
3893 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]3894 store i32 3, i32* %ptr <i>; yields {void}</i>
3895 %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]3896</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3897
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3898</div>
3899
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3900<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3901<div class="doc_subsubsection">
3902 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3903</div>
3904
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3905<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3906
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3907<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3908<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3909 &lt;result&gt; = getelementptr &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]3910 &lt;result&gt; = getelementptr inbounds &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3911</pre>
3912
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3913<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3914<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
3915 subelement of an aggregate data structure. It performs address calculation
3916 only and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3917
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3918<h5>Arguments:</h5>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3919<p>The first argument is always a pointer, and forms the basis of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3920 calculation. The remaining arguments are indices, that indicate which of the
3921 elements of the aggregate object are indexed. The interpretation of each
3922 index is dependent on the type being indexed into. The first index always
3923 indexes the pointer value given as the first argument, the second index
3924 indexes a value of the type pointed to (not necessarily the value directly
3925 pointed to, since the first index can be non-zero), etc. The first type
3926 indexed into must be a pointer value, subsequent types can be arrays, vectors
3927 and structs. Note that subsequent types being indexed into can never be
3928 pointers, since that would require loading the pointer before continuing
3929 calculation.</p>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3930
3931<p>The type of each index argument depends on the type it is indexing into.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3932 When indexing into a (packed) structure, only <tt>i32</tt> integer
3933 <b>constants</b> are allowed. When indexing into an array, pointer or
3934 vector, integers of any width are allowed (also non-constants).</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3935
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3936<p>For example, let's consider a C code fragment and how it gets compiled to
3937 LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3938
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3939<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3940<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3941struct RT {
3942 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3943 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3944 char C;
3945};
3946struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3947 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3948 double Y;
3949 struct RT Z;
3950};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3951
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3952int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3953 return &amp;s[1].Z.B[5][13];
3954}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3955</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3956</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3957
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3958<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3959
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3960<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3961<pre>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]3962%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
3963%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3964
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]3965define i32* @foo(%ST* %s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3966entry:
3967 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3968 ret i32* %reg
3969}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3970</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3971</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3972
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3973<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3974<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3975 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
3976 }</tt>' type, a structure. The second index indexes into the third element
3977 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3978 i8 }</tt>' type, another structure. The third index indexes into the second
3979 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
3980 array. The two dimensions of the array are subscripted into, yielding an
3981 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
3982 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3983
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3984<p>Note that it is perfectly legal to index partially through a structure,
3985 returning a pointer to an inner element. Because of this, the LLVM code for
3986 the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3987
3988<pre>
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]3989 define i32* @foo(%ST* %s) {
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3990 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3991 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3992 %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]3993 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3994 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
3995 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3996 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3997</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3998
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]3999<p>If the <tt>inbounds</tt> keyword is present, the result value of the
4000 <tt>getelementptr</tt> is undefined if the base pointer is not pointing
4001 into an allocated object, or if any of the addresses formed by successive
4002 addition of the offsets implied by the indices to the base address is
4003 outside of the allocated object into which the base pointer points.</p>
4004
4005<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4006 the base address with silently-wrapping two's complement arithmetic, and
4007 the result value of the <tt>getelementptr</tt> may be outside the object
4008 pointed to by the base pointer. The result value may not necessarily be
4009 used to access memory though, even if it happens to point into allocated
4010 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4011 section for more information.</p>
4012
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4013<p>The getelementptr instruction is often confusing. For some more insight into
4014 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4015
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4016<h5>Example:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4017<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4018 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4019 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4020 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4021 %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]4022 <i>; yields i8*:eptr</i>
4023 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta9f805c22009-04-25 07:27:44 +0000[diff] [blame]4024 <i>; yields i32*:iptr</i>
Sanjiv Gupta16ffa802009-04-24 16:38:13 +0000[diff] [blame]4025 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4026</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4027
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4028</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4029
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4030<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4031<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4032</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4033
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4034<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4035
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4036<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4037 which all take a single operand and a type. They perform various bit
4038 conversions on the operand.</p>
4039
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4040</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4041
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4042<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4043<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4044 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
4045</div>
4046<div class="doc_text">
4047
4048<h5>Syntax:</h5>
4049<pre>
4050 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4051</pre>
4052
4053<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4054<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4055 type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4056
4057<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4058<p>The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
4059 be an <a href="#t_integer">integer</a> type, and a type that specifies the
4060 size and type of the result, which must be
4061 an <a href="#t_integer">integer</a> type. The bit size of <tt>value</tt> must
4062 be larger than the bit size of <tt>ty2</tt>. Equal sized types are not
4063 allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4064
4065<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4066<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4067 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4068 source size must be larger than the destination size, <tt>trunc</tt> cannot
4069 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4070
4071<h5>Example:</h5>
4072<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4073 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4074 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
4075 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4076</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4077
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4078</div>
4079
4080<!-- _______________________________________________________________________ -->
4081<div class="doc_subsubsection">
4082 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
4083</div>
4084<div class="doc_text">
4085
4086<h5>Syntax:</h5>
4087<pre>
4088 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4089</pre>
4090
4091<h5>Overview:</h5>
4092<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4093 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4094
4095
4096<h5>Arguments:</h5>
4097<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4098 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4099 also be of <a href="#t_integer">integer</a> type. The bit size of the
4100 <tt>value</tt> must be smaller than the bit size of the destination type,
4101 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4102
4103<h5>Semantics:</h5>
4104<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4105 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4106
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]4107<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]4108
4109<h5>Example:</h5>
4110<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4111 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4112 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4113</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4114
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4115</div>
4116
4117<!-- _______________________________________________________________________ -->
4118<div class="doc_subsubsection">
4119 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
4120</div>
4121<div class="doc_text">
4122
4123<h5>Syntax:</h5>
4124<pre>
4125 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4126</pre>
4127
4128<h5>Overview:</h5>
4129<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4130
4131<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4132<p>The '<tt>sext</tt>' instruction takes a value to cast, which must be of
4133 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4134 also be of <a href="#t_integer">integer</a> type. The bit size of the
4135 <tt>value</tt> must be smaller than the bit size of the destination type,
4136 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4137
4138<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4139<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4140 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4141 of the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4142
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4143<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]4144
4145<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4146<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4147 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4148 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4149</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4150
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4151</div>
4152
4153<!-- _______________________________________________________________________ -->
4154<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4155 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
4156</div>
4157
4158<div class="doc_text">
4159
4160<h5>Syntax:</h5>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4161<pre>
4162 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4163</pre>
4164
4165<h5>Overview:</h5>
4166<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4167 <tt>ty2</tt>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4168
4169<h5>Arguments:</h5>
4170<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4171 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4172 to cast it to. The size of <tt>value</tt> must be larger than the size of
4173 <tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
4174 <i>no-op cast</i>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4175
4176<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4177<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
4178 <a href="#t_floating">floating point</a> type to a smaller
4179 <a href="#t_floating">floating point</a> type. If the value cannot fit
4180 within the destination type, <tt>ty2</tt>, then the results are
4181 undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4182
4183<h5>Example:</h5>
4184<pre>
4185 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4186 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4187</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4188
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4189</div>
4190
4191<!-- _______________________________________________________________________ -->
4192<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4193 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
4194</div>
4195<div class="doc_text">
4196
4197<h5>Syntax:</h5>
4198<pre>
4199 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4200</pre>
4201
4202<h5>Overview:</h5>
4203<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4204 floating point value.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4205
4206<h5>Arguments:</h5>
4207<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4208 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4209 a <a href="#t_floating">floating point</a> type to cast it to. The source
4210 type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4211
4212<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4213<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4214 <a href="#t_floating">floating point</a> type to a larger
4215 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4216 used to make a <i>no-op cast</i> because it always changes bits. Use
4217 <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]4218
4219<h5>Example:</h5>
4220<pre>
4221 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
4222 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
4223</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4224
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4225</div>
4226
4227<!-- _______________________________________________________________________ -->
4228<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]4229 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4230</div>
4231<div class="doc_text">
4232
4233<h5>Syntax:</h5>
4234<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4235 &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]4236</pre>
4237
4238<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4239<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4240 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4241
4242<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4243<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4244 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4245 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4246 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4247 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4248
4249<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4250<p>The '<tt>fptoui</tt>' instruction converts its
4251 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4252 towards zero) unsigned integer value. If the value cannot fit
4253 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4254
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4255<h5>Example:</h5>
4256<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4257 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4258 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4259 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4260</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4261
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4262</div>
4263
4264<!-- _______________________________________________________________________ -->
4265<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4266 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4267</div>
4268<div class="doc_text">
4269
4270<h5>Syntax:</h5>
4271<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4272 &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]4273</pre>
4274
4275<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4276<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4277 <a href="#t_floating">floating point</a> <tt>value</tt> to
4278 type <tt>ty2</tt>.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4279
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4280<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4281<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4282 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4283 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4284 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4285 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4286
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4287<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4288<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4289 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4290 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4291 the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4292
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]4293<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4294<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4295 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4296 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4297 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4298</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4299
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4300</div>
4301
4302<!-- _______________________________________________________________________ -->
4303<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4304 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4305</div>
4306<div class="doc_text">
4307
4308<h5>Syntax:</h5>
4309<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4310 &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]4311</pre>
4312
4313<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4314<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4315 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4316
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4317<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]4318<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4319 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4320 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4321 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4322 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4323
4324<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4325<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4326 integer quantity and converts it to the corresponding floating point
4327 value. If the value cannot fit in the floating point value, the results are
4328 undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4329
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4330<h5>Example:</h5>
4331<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4332 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4333 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4334</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4335
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4336</div>
4337
4338<!-- _______________________________________________________________________ -->
4339<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4340 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4341</div>
4342<div class="doc_text">
4343
4344<h5>Syntax:</h5>
4345<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4346 &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]4347</pre>
4348
4349<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4350<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
4351 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4352
4353<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]4354<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4355 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4356 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4357 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4358 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4359
4360<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4361<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
4362 quantity and converts it to the corresponding floating point value. If the
4363 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4364
4365<h5>Example:</h5>
4366<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4367 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4368 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4369</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4370
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4371</div>
4372
4373<!-- _______________________________________________________________________ -->
4374<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4375 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
4376</div>
4377<div class="doc_text">
4378
4379<h5>Syntax:</h5>
4380<pre>
4381 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4382</pre>
4383
4384<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4385<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
4386 the integer type <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4387
4388<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4389<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
4390 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
4391 <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]4392
4393<h5>Semantics:</h5>
4394<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4395 <tt>ty2</tt> by interpreting the pointer value as an integer and either
4396 truncating or zero extending that value to the size of the integer type. If
4397 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
4398 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
4399 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
4400 change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4401
4402<h5>Example:</h5>
4403<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4404 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
4405 %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]4406</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4407
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4408</div>
4409
4410<!-- _______________________________________________________________________ -->
4411<div class="doc_subsubsection">
4412 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
4413</div>
4414<div class="doc_text">
4415
4416<h5>Syntax:</h5>
4417<pre>
4418 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4419</pre>
4420
4421<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4422<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
4423 pointer type, <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4424
4425<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4426<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4427 value to cast, and a type to cast it to, which must be a
4428 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4429
4430<h5>Semantics:</h5>
4431<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4432 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
4433 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
4434 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
4435 than the size of a pointer then a zero extension is done. If they are the
4436 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4437
4438<h5>Example:</h5>
4439<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4440 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
4441 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
4442 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4443</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4444
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4445</div>
4446
4447<!-- _______________________________________________________________________ -->
4448<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4449 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4450</div>
4451<div class="doc_text">
4452
4453<h5>Syntax:</h5>
4454<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4455 &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]4456</pre>
4457
4458<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4459<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4460 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4461
4462<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4463<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
4464 non-aggregate first class value, and a type to cast it to, which must also be
4465 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
4466 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
4467 identical. If the source type is a pointer, the destination type must also be
4468 a pointer. This instruction supports bitwise conversion of vectors to
4469 integers and to vectors of other types (as long as they have the same
4470 size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4471
4472<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4473<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4474 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
4475 this conversion. The conversion is done as if the <tt>value</tt> had been
4476 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
4477 be converted to other pointer types with this instruction. To convert
4478 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
4479 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4480
4481<h5>Example:</h5>
4482<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4483 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4484 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4485 %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]4486</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4487
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4488</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4489
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4490<!-- ======================================================================= -->
4491<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4492
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4493<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4494
4495<p>The instructions in this category are the "miscellaneous" instructions, which
4496 defy better classification.</p>
4497
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4498</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4499
4500<!-- _______________________________________________________________________ -->
4501<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4502</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4503
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4504<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4505
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4506<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4507<pre>
4508 &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]4509</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4510
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4511<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4512<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
4513 boolean values based on comparison of its two integer, integer vector, or
4514 pointer operands.</p>
4515
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4516<h5>Arguments:</h5>
4517<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4518 the condition code indicating the kind of comparison to perform. It is not a
4519 value, just a keyword. The possible condition code are:</p>
4520
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4521<ol>
4522 <li><tt>eq</tt>: equal</li>
4523 <li><tt>ne</tt>: not equal </li>
4524 <li><tt>ugt</tt>: unsigned greater than</li>
4525 <li><tt>uge</tt>: unsigned greater or equal</li>
4526 <li><tt>ult</tt>: unsigned less than</li>
4527 <li><tt>ule</tt>: unsigned less or equal</li>
4528 <li><tt>sgt</tt>: signed greater than</li>
4529 <li><tt>sge</tt>: signed greater or equal</li>
4530 <li><tt>slt</tt>: signed less than</li>
4531 <li><tt>sle</tt>: signed less or equal</li>
4532</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4533
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]4534<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4535 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
4536 typed. They must also be identical types.</p>
4537
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4538<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4539<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
4540 condition code given as <tt>cond</tt>. The comparison performed always yields
4541 either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt>
4542 result, as follows:</p>
4543
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4544<ol>
4545 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4546 <tt>false</tt> otherwise. No sign interpretation is necessary or
4547 performed.</li>
4548
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4549 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4550 <tt>false</tt> otherwise. No sign interpretation is necessary or
4551 performed.</li>
4552
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4553 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4554 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4555
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4556 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4557 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4558 to <tt>op2</tt>.</li>
4559
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4560 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4561 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4562
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4563 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4564 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4565
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4566 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4567 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4568
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4569 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4570 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4571 to <tt>op2</tt>.</li>
4572
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4573 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4574 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4575
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4576 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4577 <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]4578</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4579
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4580<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4581 values are compared as if they were integers.</p>
4582
4583<p>If the operands are integer vectors, then they are compared element by
4584 element. The result is an <tt>i1</tt> vector with the same number of elements
4585 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4586
4587<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4588<pre>
4589 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4590 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4591 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4592 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4593 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4594 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4595</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4596
4597<p>Note that the code generator does not yet support vector types with
4598 the <tt>icmp</tt> instruction.</p>
4599
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4600</div>
4601
4602<!-- _______________________________________________________________________ -->
4603<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4604</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4605
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4606<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4607
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4608<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4609<pre>
4610 &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]4611</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4612
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4613<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4614<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
4615 values based on comparison of its operands.</p>
4616
4617<p>If the operands are floating point scalars, then the result type is a boolean
4618(<a href="#t_primitive"><tt>i1</tt></a>).</p>
4619
4620<p>If the operands are floating point vectors, then the result type is a vector
4621 of boolean with the same number of elements as the operands being
4622 compared.</p>
4623
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4624<h5>Arguments:</h5>
4625<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4626 the condition code indicating the kind of comparison to perform. It is not a
4627 value, just a keyword. The possible condition code are:</p>
4628
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4629<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4630 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4631 <li><tt>oeq</tt>: ordered and equal</li>
4632 <li><tt>ogt</tt>: ordered and greater than </li>
4633 <li><tt>oge</tt>: ordered and greater than or equal</li>
4634 <li><tt>olt</tt>: ordered and less than </li>
4635 <li><tt>ole</tt>: ordered and less than or equal</li>
4636 <li><tt>one</tt>: ordered and not equal</li>
4637 <li><tt>ord</tt>: ordered (no nans)</li>
4638 <li><tt>ueq</tt>: unordered or equal</li>
4639 <li><tt>ugt</tt>: unordered or greater than </li>
4640 <li><tt>uge</tt>: unordered or greater than or equal</li>
4641 <li><tt>ult</tt>: unordered or less than </li>
4642 <li><tt>ule</tt>: unordered or less than or equal</li>
4643 <li><tt>une</tt>: unordered or not equal</li>
4644 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4645 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4646</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4647
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4648<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4649 <i>unordered</i> means that either operand may be a QNAN.</p>
4650
4651<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
4652 a <a href="#t_floating">floating point</a> type or
4653 a <a href="#t_vector">vector</a> of floating point type. They must have
4654 identical types.</p>
4655
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4656<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4657<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4658 according to the condition code given as <tt>cond</tt>. If the operands are
4659 vectors, then the vectors are compared element by element. Each comparison
4660 performed always yields an <a href="#t_primitive">i1</a> result, as
4661 follows:</p>
4662
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4663<ol>
4664 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4665
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4666 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4667 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
4668
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4669 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4670 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
4671
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4672 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4673 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
4674
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4675 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4676 <tt>op1</tt> is less than <tt>op2</tt>.</li>
4677
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4678 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4679 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4680
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4681 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4682 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
4683
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4684 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4685
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4686 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4687 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
4688
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4689 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4690 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4691
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4692 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4693 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
4694
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4695 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4696 <tt>op1</tt> is less than <tt>op2</tt>.</li>
4697
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4698 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4699 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4700
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4701 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4702 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
4703
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4704 <li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4705
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4706 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4707</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4708
4709<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4710<pre>
4711 &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]4712 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4713 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4714 &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]4715</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4716
4717<p>Note that the code generator does not yet support vector types with
4718 the <tt>fcmp</tt> instruction.</p>
4719
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4720</div>
4721
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4722<!-- _______________________________________________________________________ -->
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4723<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4724 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4725</div>
4726
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4727<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4728
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4729<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4730<pre>
4731 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
4732</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4733
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4734<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4735<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
4736 SSA graph representing the function.</p>
4737
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4738<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4739<p>The type of the incoming values is specified with the first type field. After
4740 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
4741 one pair for each predecessor basic block of the current block. Only values
4742 of <a href="#t_firstclass">first class</a> type may be used as the value
4743 arguments to the PHI node. Only labels may be used as the label
4744 arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4745
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4746<p>There must be no non-phi instructions between the start of a basic block and
4747 the PHI instructions: i.e. PHI instructions must be first in a basic
4748 block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4749
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4750<p>For the purposes of the SSA form, the use of each incoming value is deemed to
4751 occur on the edge from the corresponding predecessor block to the current
4752 block (but after any definition of an '<tt>invoke</tt>' instruction's return
4753 value on the same edge).</p>
Jay Foadd2449092009-06-03 10:20:10 +0000[diff] [blame]4754
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4755<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4756<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4757 specified by the pair corresponding to the predecessor basic block that
4758 executed just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4759
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4760<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4761<pre>
4762Loop: ; Infinite loop that counts from 0 on up...
4763 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4764 %nextindvar = add i32 %indvar, 1
4765 br label %Loop
4766</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4767
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4768</div>
4769
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4770<!-- _______________________________________________________________________ -->
4771<div class="doc_subsubsection">
4772 <a name="i_select">'<tt>select</tt>' Instruction</a>
4773</div>
4774
4775<div class="doc_text">
4776
4777<h5>Syntax:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4778<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4779 &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>
4780
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4781 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4782</pre>
4783
4784<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4785<p>The '<tt>select</tt>' instruction is used to choose one value based on a
4786 condition, without branching.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4787
4788
4789<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4790<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
4791 values indicating the condition, and two values of the
4792 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
4793 vectors and the condition is a scalar, then entire vectors are selected, not
4794 individual elements.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4795
4796<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4797<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
4798 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4799
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4800<p>If the condition is a vector of i1, then the value arguments must be vectors
4801 of the same size, and the selection is done element by element.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4802
4803<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4804<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4805 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4806</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4807
4808<p>Note that the code generator does not yet support conditions
4809 with vector type.</p>
4810
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4811</div>
4812
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]4813<!-- _______________________________________________________________________ -->
4814<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4815 <a name="i_call">'<tt>call</tt>' Instruction</a>
4816</div>
4817
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4818<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4819
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4820<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4821<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]4822 &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]4823</pre>
4824
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4825<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4826<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4827
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4828<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4829<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4830
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4831<ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4832 <li>The optional "tail" marker indicates whether the callee function accesses
4833 any allocas or varargs in the caller. If the "tail" marker is present,
4834 the function call is eligible for tail call optimization. Note that calls
4835 may be marked "tail" even if they do not occur before
4836 a <a href="#i_ret"><tt>ret</tt></a> instruction.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4837
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4838 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
4839 convention</a> the call should use. If none is specified, the call
4840 defaults to using C calling conventions.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4841
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4842 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4843 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
4844 '<tt>inreg</tt>' attributes are valid here.</li>
4845
4846 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
4847 type of the return value. Functions that return no value are marked
4848 <tt><a href="#t_void">void</a></tt>.</li>
4849
4850 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
4851 being invoked. The argument types must match the types implied by this
4852 signature. This type can be omitted if the function is not varargs and if
4853 the function type does not return a pointer to a function.</li>
4854
4855 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4856 be invoked. In most cases, this is a direct function invocation, but
4857 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
4858 to function value.</li>
4859
4860 <li>'<tt>function args</tt>': argument list whose types match the function
4861 signature argument types. All arguments must be of
4862 <a href="#t_firstclass">first class</a> type. If the function signature
4863 indicates the function accepts a variable number of arguments, the extra
4864 arguments can be specified.</li>
4865
4866 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
4867 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
4868 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4869</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4870
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4871<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4872<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
4873 a specified function, with its incoming arguments bound to the specified
4874 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
4875 function, control flow continues with the instruction after the function
4876 call, and the return value of the function is bound to the result
4877 argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4878
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4879<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4880<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4881 %retval = call i32 @test(i32 %argc)
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]4882 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4883 %X = tail call i32 @foo() <i>; yields i32</i>
4884 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4885 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]4886
4887 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4888 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]4889 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
4890 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]4891 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]4892 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4893</pre>
4894
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4895</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4896
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4897<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4898<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]4899 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4900</div>
4901
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4902<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4903
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4904<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4905<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4906 &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]4907</pre>
4908
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4909<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4910<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4911 the "variable argument" area of a function call. It is used to implement the
4912 <tt>va_arg</tt> macro in C.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4913
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4914<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4915<p>This instruction takes a <tt>va_list*</tt> value and the type of the
4916 argument. It returns a value of the specified argument type and increments
4917 the <tt>va_list</tt> to point to the next argument. The actual type
4918 of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4919
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4920<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4921<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
4922 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
4923 to the next argument. For more information, see the variable argument
4924 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4925
4926<p>It is legal for this instruction to be called in a function which does not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4927 take a variable number of arguments, for example, the <tt>vfprintf</tt>
4928 function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4929
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4930<p><tt>va_arg</tt> is an LLVM instruction instead of
4931 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
4932 argument.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4933
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4934<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4935<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4936
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4937<p>Note that the code generator does not yet fully support va_arg on many
4938 targets. Also, it does not currently support va_arg with aggregate types on
4939 any target.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]4940
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4941</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4942
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4943<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4944<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4945<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4946
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4947<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4948
4949<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4950 well known names and semantics and are required to follow certain
4951 restrictions. Overall, these intrinsics represent an extension mechanism for
4952 the LLVM language that does not require changing all of the transformations
4953 in LLVM when adding to the language (or the bitcode reader/writer, the
4954 parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4955
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4956<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4957 prefix is reserved in LLVM for intrinsic names; thus, function names may not
4958 begin with this prefix. Intrinsic functions must always be external
4959 functions: you cannot define the body of intrinsic functions. Intrinsic
4960 functions may only be used in call or invoke instructions: it is illegal to
4961 take the address of an intrinsic function. Additionally, because intrinsic
4962 functions are part of the LLVM language, it is required if any are added that
4963 they be documented here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4964
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4965<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
4966 family of functions that perform the same operation but on different data
4967 types. Because LLVM can represent over 8 million different integer types,
4968 overloading is used commonly to allow an intrinsic function to operate on any
4969 integer type. One or more of the argument types or the result type can be
4970 overloaded to accept any integer type. Argument types may also be defined as
4971 exactly matching a previous argument's type or the result type. This allows
4972 an intrinsic function which accepts multiple arguments, but needs all of them
4973 to be of the same type, to only be overloaded with respect to a single
4974 argument or the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4975
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4976<p>Overloaded intrinsics will have the names of its overloaded argument types
4977 encoded into its function name, each preceded by a period. Only those types
4978 which are overloaded result in a name suffix. Arguments whose type is matched
4979 against another type do not. For example, the <tt>llvm.ctpop</tt> function
4980 can take an integer of any width and returns an integer of exactly the same
4981 integer width. This leads to a family of functions such as
4982 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
4983 %val)</tt>. Only one type, the return type, is overloaded, and only one type
4984 suffix is required. Because the argument's type is matched against the return
4985 type, it does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4986
4987<p>To learn how to add an intrinsic function, please see the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4988 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4989
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4990</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4991
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4992<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4993<div class="doc_subsection">
4994 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
4995</div>
4996
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4997<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4998
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4999<p>Variable argument support is defined in LLVM with
5000 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5001 intrinsic functions. These functions are related to the similarly named
5002 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5003
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5004<p>All of these functions operate on arguments that use a target-specific value
5005 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5006 not define what this type is, so all transformations should be prepared to
5007 handle these functions regardless of the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5008
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]5009<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5010 instruction and the variable argument handling intrinsic functions are
5011 used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5012
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5013<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5014<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5015define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5016 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5017 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5018 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5019 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5020
5021 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5022 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5023
5024 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5025 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5026 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5027 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5028 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5029
5030 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5031 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5032 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5033}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5034
5035declare void @llvm.va_start(i8*)
5036declare void @llvm.va_copy(i8*, i8*)
5037declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5038</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5039</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5040
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5041</div>
5042
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5043<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5044<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5045 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5046</div>
5047
5048
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5049<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5050
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5051<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5052<pre>
5053 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5054</pre>
5055
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5056<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5057<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5058 for subsequent use by <tt><a href="#i_va_arg">va_arg</a></tt>.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5059
5060<h5>Arguments:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5061<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]5062
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5063<h5>Semantics:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5064<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5065 macro available in C. In a target-dependent way, it initializes
5066 the <tt>va_list</tt> element to which the argument points, so that the next
5067 call to <tt>va_arg</tt> will produce the first variable argument passed to
5068 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5069 need to know the last argument of the function as the compiler can figure
5070 that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5071
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5072</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5073
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5074<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5075<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5076 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5077</div>
5078
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5079<div class="doc_text">
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5080
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5081<h5>Syntax:</h5>
5082<pre>
5083 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5084</pre>
5085
5086<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5087<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5088 which has been initialized previously
5089 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5090 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5091
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5092<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5093<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]5094
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5095<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5096<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5097 macro available in C. In a target-dependent way, it destroys
5098 the <tt>va_list</tt> element to which the argument points. Calls
5099 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5100 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5101 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5102
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5103</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5104
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5105<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5106<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5107 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5108</div>
5109
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5110<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5111
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5112<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5113<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5114 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5115</pre>
5116
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5117<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5118<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5119 from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5120
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5121<h5>Arguments:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5122<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5123 The second argument is a pointer to a <tt>va_list</tt> element to copy
5124 from.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5125
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5126<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5127<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5128 macro available in C. In a target-dependent way, it copies the
5129 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5130 element. This intrinsic is necessary because
5131 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5132 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5133
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5134</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5135
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5136<!-- ======================================================================= -->
5137<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5138 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
5139</div>
5140
5141<div class="doc_text">
5142
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5143<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5144Collection</a> (GC) requires the implementation and generation of these
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5145intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5146roots on the stack</a>, as well as garbage collector implementations that
5147require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5148barriers. Front-ends for type-safe garbage collected languages should generate
5149these intrinsics to make use of the LLVM garbage collectors. For more details,
5150see <a href="GarbageCollection.html">Accurate Garbage Collection with
5151LLVM</a>.</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5152
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5153<p>The garbage collection intrinsics only operate on objects in the generic
5154 address space (address space zero).</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5155
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5156</div>
5157
5158<!-- _______________________________________________________________________ -->
5159<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5160 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5161</div>
5162
5163<div class="doc_text">
5164
5165<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5166<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5167 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5168</pre>
5169
5170<h5>Overview:</h5>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]5171<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5172 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5173
5174<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5175<p>The first argument specifies the address of a stack object that contains the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5176 root pointer. The second pointer (which must be either a constant or a
5177 global value address) contains the meta-data to be associated with the
5178 root.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5179
5180<h5>Semantics:</h5>
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]5181<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5182 location. At compile-time, the code generator generates information to allow
5183 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5184 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5185 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5186
5187</div>
5188
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5189<!-- _______________________________________________________________________ -->
5190<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5191 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5192</div>
5193
5194<div class="doc_text">
5195
5196<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5197<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5198 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5199</pre>
5200
5201<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5202<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5203 locations, allowing garbage collector implementations that require read
5204 barriers.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5205
5206<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5207<p>The second argument is the address to read from, which should be an address
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5208 allocated from the garbage collector. The first object is a pointer to the
5209 start of the referenced object, if needed by the language runtime (otherwise
5210 null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5211
5212<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5213<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5214 instruction, but may be replaced with substantially more complex code by the
5215 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5216 may only be used in a function which <a href="#gc">specifies a GC
5217 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5218
5219</div>
5220
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5221<!-- _______________________________________________________________________ -->
5222<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5223 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5224</div>
5225
5226<div class="doc_text">
5227
5228<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5229<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5230 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5231</pre>
5232
5233<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5234<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5235 locations, allowing garbage collector implementations that require write
5236 barriers (such as generational or reference counting collectors).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5237
5238<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5239<p>The first argument is the reference to store, the second is the start of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5240 object to store it to, and the third is the address of the field of Obj to
5241 store to. If the runtime does not require a pointer to the object, Obj may
5242 be null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5243
5244<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5245<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5246 instruction, but may be replaced with substantially more complex code by the
5247 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5248 may only be used in a function which <a href="#gc">specifies a GC
5249 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5250
5251</div>
5252
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5253<!-- ======================================================================= -->
5254<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5255 <a name="int_codegen">Code Generator Intrinsics</a>
5256</div>
5257
5258<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5259
5260<p>These intrinsics are provided by LLVM to expose special features that may
5261 only be implemented with code generator support.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5262
5263</div>
5264
5265<!-- _______________________________________________________________________ -->
5266<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5267 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5268</div>
5269
5270<div class="doc_text">
5271
5272<h5>Syntax:</h5>
5273<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5274 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5275</pre>
5276
5277<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5278<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5279 target-specific value indicating the return address of the current function
5280 or one of its callers.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5281
5282<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5283<p>The argument to this intrinsic indicates which function to return the address
5284 for. Zero indicates the calling function, one indicates its caller, etc.
5285 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5286
5287<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5288<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5289 indicating the return address of the specified call frame, or zero if it
5290 cannot be identified. The value returned by this intrinsic is likely to be
5291 incorrect or 0 for arguments other than zero, so it should only be used for
5292 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5293
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5294<p>Note that calling this intrinsic does not prevent function inlining or other
5295 aggressive transformations, so the value returned may not be that of the
5296 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5297
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5298</div>
5299
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5300<!-- _______________________________________________________________________ -->
5301<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5302 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5303</div>
5304
5305<div class="doc_text">
5306
5307<h5>Syntax:</h5>
5308<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5309 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5310</pre>
5311
5312<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5313<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5314 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5315
5316<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5317<p>The argument to this intrinsic indicates which function to return the frame
5318 pointer for. Zero indicates the calling function, one indicates its caller,
5319 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5320
5321<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5322<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
5323 indicating the frame address of the specified call frame, or zero if it
5324 cannot be identified. The value returned by this intrinsic is likely to be
5325 incorrect or 0 for arguments other than zero, so it should only be used for
5326 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5327
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5328<p>Note that calling this intrinsic does not prevent function inlining or other
5329 aggressive transformations, so the value returned may not be that of the
5330 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5331
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5332</div>
5333
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5334<!-- _______________________________________________________________________ -->
5335<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5336 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5337</div>
5338
5339<div class="doc_text">
5340
5341<h5>Syntax:</h5>
5342<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5343 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5344</pre>
5345
5346<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5347<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
5348 of the function stack, for use
5349 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
5350 useful for implementing language features like scoped automatic variable
5351 sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5352
5353<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5354<p>This intrinsic returns a opaque pointer value that can be passed
5355 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
5356 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
5357 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
5358 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
5359 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
5360 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5361
5362</div>
5363
5364<!-- _______________________________________________________________________ -->
5365<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5366 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5367</div>
5368
5369<div class="doc_text">
5370
5371<h5>Syntax:</h5>
5372<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5373 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5374</pre>
5375
5376<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5377<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5378 the function stack to the state it was in when the
5379 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
5380 executed. This is useful for implementing language features like scoped
5381 automatic variable sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5382
5383<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5384<p>See the description
5385 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5386
5387</div>
5388
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5389<!-- _______________________________________________________________________ -->
5390<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5391 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5392</div>
5393
5394<div class="doc_text">
5395
5396<h5>Syntax:</h5>
5397<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5398 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]5399</pre>
5400
5401<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5402<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
5403 insert a prefetch instruction if supported; otherwise, it is a noop.
5404 Prefetches have no effect on the behavior of the program but can change its
5405 performance characteristics.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5406
5407<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5408<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
5409 specifier determining if the fetch should be for a read (0) or write (1),
5410 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
5411 locality, to (3) - extremely local keep in cache. The <tt>rw</tt>
5412 and <tt>locality</tt> arguments must be constant integers.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5413
5414<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5415<p>This intrinsic does not modify the behavior of the program. In particular,
5416 prefetches cannot trap and do not produce a value. On targets that support
5417 this intrinsic, the prefetch can provide hints to the processor cache for
5418 better performance.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5419
5420</div>
5421
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5422<!-- _______________________________________________________________________ -->
5423<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5424 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5425</div>
5426
5427<div class="doc_text">
5428
5429<h5>Syntax:</h5>
5430<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5431 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5432</pre>
5433
5434<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5435<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
5436 Counter (PC) in a region of code to simulators and other tools. The method
5437 is target specific, but it is expected that the marker will use exported
5438 symbols to transmit the PC of the marker. The marker makes no guarantees
5439 that it will remain with any specific instruction after optimizations. It is
5440 possible that the presence of a marker will inhibit optimizations. The
5441 intended use is to be inserted after optimizations to allow correlations of
5442 simulation runs.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5443
5444<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5445<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5446
5447<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5448<p>This intrinsic does not modify the behavior of the program. Backends that do
5449 not support this intrinisic may ignore it.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5450
5451</div>
5452
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5453<!-- _______________________________________________________________________ -->
5454<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5455 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5456</div>
5457
5458<div class="doc_text">
5459
5460<h5>Syntax:</h5>
5461<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5462 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5463</pre>
5464
5465<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5466<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5467 counter register (or similar low latency, high accuracy clocks) on those
5468 targets that support it. On X86, it should map to RDTSC. On Alpha, it
5469 should map to RPCC. As the backing counters overflow quickly (on the order
5470 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5471
5472<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5473<p>When directly supported, reading the cycle counter should not modify any
5474 memory. Implementations are allowed to either return a application specific
5475 value or a system wide value. On backends without support, this is lowered
5476 to a constant 0.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5477
5478</div>
5479
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5480<!-- ======================================================================= -->
5481<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5482 <a name="int_libc">Standard C Library Intrinsics</a>
5483</div>
5484
5485<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5486
5487<p>LLVM provides intrinsics for a few important standard C library functions.
5488 These intrinsics allow source-language front-ends to pass information about
5489 the alignment of the pointer arguments to the code generator, providing
5490 opportunity for more efficient code generation.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5491
5492</div>
5493
5494<!-- _______________________________________________________________________ -->
5495<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5496 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5497</div>
5498
5499<div class="doc_text">
5500
5501<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5502<p>This is an overloaded intrinsic. You can use <tt>llvm.memcpy</tt> on any
5503 integer bit width. Not all targets support all bit widths however.</p>
5504
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5505<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5506 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5507 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5508 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5509 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5510 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5511 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5512 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5513 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5514</pre>
5515
5516<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5517<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5518 source location to the destination location.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5519
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5520<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5521 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5522
5523<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5524<p>The first argument is a pointer to the destination, the second is a pointer
5525 to the source. The third argument is an integer argument specifying the
5526 number of bytes to copy, and the fourth argument is the alignment of the
5527 source and destination locations.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5528
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5529<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5530 then the caller guarantees that both the source and destination pointers are
5531 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5532
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5533<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5534<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5535 source location to the destination location, which are not allowed to
5536 overlap. It copies "len" bytes of memory over. If the argument is known to
5537 be aligned to some boundary, this can be specified as the fourth argument,
5538 otherwise it should be set to 0 or 1.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5539
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5540</div>
5541
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5542<!-- _______________________________________________________________________ -->
5543<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5544 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5545</div>
5546
5547<div class="doc_text">
5548
5549<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5550<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5551 width. Not all targets support all bit widths however.</p>
5552
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5553<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5554 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5555 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5556 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5557 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5558 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5559 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5560 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5561 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5562</pre>
5563
5564<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5565<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
5566 source location to the destination location. It is similar to the
5567 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
5568 overlap.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5569
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5570<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5571 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5572
5573<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5574<p>The first argument is a pointer to the destination, the second is a pointer
5575 to the source. The third argument is an integer argument specifying the
5576 number of bytes to copy, and the fourth argument is the alignment of the
5577 source and destination locations.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5578
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5579<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5580 then the caller guarantees that the source and destination pointers are
5581 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5582
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5583<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5584<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
5585 source location to the destination location, which may overlap. It copies
5586 "len" bytes of memory over. If the argument is known to be aligned to some
5587 boundary, this can be specified as the fourth argument, otherwise it should
5588 be set to 0 or 1.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5589
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5590</div>
5591
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5592<!-- _______________________________________________________________________ -->
5593<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5594 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5595</div>
5596
5597<div class="doc_text">
5598
5599<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5600<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5601 width. Not all targets support all bit widths however.</p>
5602
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5603<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5604 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5605 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5606 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5607 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5608 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5609 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5610 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5611 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5612</pre>
5613
5614<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5615<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
5616 particular byte value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5617
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5618<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
5619 intrinsic does not return a value, and takes an extra alignment argument.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5620
5621<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5622<p>The first argument is a pointer to the destination to fill, the second is the
5623 byte value to fill it with, the third argument is an integer argument
5624 specifying the number of bytes to fill, and the fourth argument is the known
5625 alignment of destination location.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5626
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5627<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5628 then the caller guarantees that the destination pointer is aligned to that
5629 boundary.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5630
5631<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5632<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
5633 at the destination location. If the argument is known to be aligned to some
5634 boundary, this can be specified as the fourth argument, otherwise it should
5635 be set to 0 or 1.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5636
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5637</div>
5638
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5639<!-- _______________________________________________________________________ -->
5640<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5641 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5642</div>
5643
5644<div class="doc_text">
5645
5646<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5647<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
5648 floating point or vector of floating point type. Not all targets support all
5649 types however.</p>
5650
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5651<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5652 declare float @llvm.sqrt.f32(float %Val)
5653 declare double @llvm.sqrt.f64(double %Val)
5654 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5655 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5656 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5657</pre>
5658
5659<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5660<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
5661 returning the same value as the libm '<tt>sqrt</tt>' functions would.
5662 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
5663 behavior for negative numbers other than -0.0 (which allows for better
5664 optimization, because there is no need to worry about errno being
5665 set). <tt>llvm.sqrt(-0.0)</tt> is defined to return -0.0 like IEEE sqrt.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5666
5667<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5668<p>The argument and return value are floating point numbers of the same
5669 type.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5670
5671<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5672<p>This function returns the sqrt of the specified operand if it is a
5673 nonnegative floating point number.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5674
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5675</div>
5676
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5677<!-- _______________________________________________________________________ -->
5678<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5679 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5680</div>
5681
5682<div class="doc_text">
5683
5684<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5685<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
5686 floating point or vector of floating point type. Not all targets support all
5687 types however.</p>
5688
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5689<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5690 declare float @llvm.powi.f32(float %Val, i32 %power)
5691 declare double @llvm.powi.f64(double %Val, i32 %power)
5692 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5693 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5694 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5695</pre>
5696
5697<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5698<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5699 specified (positive or negative) power. The order of evaluation of
5700 multiplications is not defined. When a vector of floating point type is
5701 used, the second argument remains a scalar integer value.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5702
5703<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5704<p>The second argument is an integer power, and the first is a value to raise to
5705 that power.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5706
5707<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5708<p>This function returns the first value raised to the second power with an
5709 unspecified sequence of rounding operations.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5710
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5711</div>
5712
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5713<!-- _______________________________________________________________________ -->
5714<div class="doc_subsubsection">
5715 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5716</div>
5717
5718<div class="doc_text">
5719
5720<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5721<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5722 floating point or vector of floating point type. Not all targets support all
5723 types however.</p>
5724
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5725<pre>
5726 declare float @llvm.sin.f32(float %Val)
5727 declare double @llvm.sin.f64(double %Val)
5728 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5729 declare fp128 @llvm.sin.f128(fp128 %Val)
5730 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5731</pre>
5732
5733<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5734<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5735
5736<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5737<p>The argument and return value are floating point numbers of the same
5738 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5739
5740<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5741<p>This function returns the sine of the specified operand, returning the same
5742 values as the libm <tt>sin</tt> functions would, and handles error conditions
5743 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5744
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5745</div>
5746
5747<!-- _______________________________________________________________________ -->
5748<div class="doc_subsubsection">
5749 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5750</div>
5751
5752<div class="doc_text">
5753
5754<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5755<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5756 floating point or vector of floating point type. Not all targets support all
5757 types however.</p>
5758
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5759<pre>
5760 declare float @llvm.cos.f32(float %Val)
5761 declare double @llvm.cos.f64(double %Val)
5762 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5763 declare fp128 @llvm.cos.f128(fp128 %Val)
5764 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5765</pre>
5766
5767<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5768<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5769
5770<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5771<p>The argument and return value are floating point numbers of the same
5772 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5773
5774<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5775<p>This function returns the cosine of the specified operand, returning the same
5776 values as the libm <tt>cos</tt> functions would, and handles error conditions
5777 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5778
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5779</div>
5780
5781<!-- _______________________________________________________________________ -->
5782<div class="doc_subsubsection">
5783 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5784</div>
5785
5786<div class="doc_text">
5787
5788<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5789<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5790 floating point or vector of floating point type. Not all targets support all
5791 types however.</p>
5792
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5793<pre>
5794 declare float @llvm.pow.f32(float %Val, float %Power)
5795 declare double @llvm.pow.f64(double %Val, double %Power)
5796 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5797 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5798 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5799</pre>
5800
5801<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5802<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5803 specified (positive or negative) power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5804
5805<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5806<p>The second argument is a floating point power, and the first is a value to
5807 raise to that power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5808
5809<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5810<p>This function returns the first value raised to the second power, returning
5811 the same values as the libm <tt>pow</tt> functions would, and handles error
5812 conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5813
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5814</div>
5815
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5816<!-- ======================================================================= -->
5817<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5818 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5819</div>
5820
5821<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5822
5823<p>LLVM provides intrinsics for a few important bit manipulation operations.
5824 These allow efficient code generation for some algorithms.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5825
5826</div>
5827
5828<!-- _______________________________________________________________________ -->
5829<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5830 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5831</div>
5832
5833<div class="doc_text">
5834
5835<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5836<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5837 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
5838
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5839<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5840 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5841 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5842 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5843</pre>
5844
5845<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5846<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
5847 values with an even number of bytes (positive multiple of 16 bits). These
5848 are useful for performing operations on data that is not in the target's
5849 native byte order.</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5850
5851<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5852<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
5853 and low byte of the input i16 swapped. Similarly,
5854 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
5855 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
5856 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
5857 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
5858 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
5859 more, respectively).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5860
5861</div>
5862
5863<!-- _______________________________________________________________________ -->
5864<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5865 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5866</div>
5867
5868<div class="doc_text">
5869
5870<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5871<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5872 width. Not all targets support all bit widths however.</p>
5873
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5874<pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5875 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5876 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5877 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5878 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5879 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5880</pre>
5881
5882<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5883<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
5884 in a value.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5885
5886<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5887<p>The only argument is the value to be counted. The argument may be of any
5888 integer type. The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5889
5890<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5891<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5892
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5893</div>
5894
5895<!-- _______________________________________________________________________ -->
5896<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5897 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5898</div>
5899
5900<div class="doc_text">
5901
5902<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5903<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
5904 integer bit width. Not all targets support all bit widths however.</p>
5905
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5906<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5907 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5908 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5909 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5910 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5911 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5912</pre>
5913
5914<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5915<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5916 leading zeros in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5917
5918<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5919<p>The only argument is the value to be counted. The argument may be of any
5920 integer type. The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5921
5922<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5923<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
5924 zeros in a variable. If the src == 0 then the result is the size in bits of
5925 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5926
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5927</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5928
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5929<!-- _______________________________________________________________________ -->
5930<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5931 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5932</div>
5933
5934<div class="doc_text">
5935
5936<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5937<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
5938 integer bit width. Not all targets support all bit widths however.</p>
5939
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5940<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5941 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5942 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5943 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5944 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5945 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5946</pre>
5947
5948<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5949<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5950 trailing zeros.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5951
5952<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5953<p>The only argument is the value to be counted. The argument may be of any
5954 integer type. The return type must match the argument type.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5955
5956<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5957<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
5958 zeros in a variable. If the src == 0 then the result is the size in bits of
5959 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5960
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5961</div>
5962
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5963<!-- ======================================================================= -->
5964<div class="doc_subsection">
5965 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
5966</div>
5967
5968<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5969
5970<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5971
5972</div>
5973
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5974<!-- _______________________________________________________________________ -->
5975<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5976 <a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5977</div>
5978
5979<div class="doc_text">
5980
5981<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5982<p>This is an overloaded intrinsic. You can use <tt>llvm.sadd.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5983 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5984
5985<pre>
5986 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
5987 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
5988 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
5989</pre>
5990
5991<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5992<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5993 a signed addition of the two arguments, and indicate whether an overflow
5994 occurred during the signed summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5995
5996<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5997<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5998 be of integer types of any bit width, but they must have the same bit
5999 width. The second element of the result structure must be of
6000 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6001 undergo signed addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6002
6003<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6004<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6005 a signed addition of the two variables. They return a structure &mdash; the
6006 first element of which is the signed summation, and the second element of
6007 which is a bit specifying if the signed summation resulted in an
6008 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6009
6010<h5>Examples:</h5>
6011<pre>
6012 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6013 %sum = extractvalue {i32, i1} %res, 0
6014 %obit = extractvalue {i32, i1} %res, 1
6015 br i1 %obit, label %overflow, label %normal
6016</pre>
6017
6018</div>
6019
6020<!-- _______________________________________________________________________ -->
6021<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6022 <a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6023</div>
6024
6025<div class="doc_text">
6026
6027<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6028<p>This is an overloaded intrinsic. You can use <tt>llvm.uadd.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6029 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6030
6031<pre>
6032 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6033 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6034 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6035</pre>
6036
6037<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6038<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6039 an unsigned addition of the two arguments, and indicate whether a carry
6040 occurred during the unsigned summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6041
6042<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6043<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6044 be of integer types of any bit width, but they must have the same bit
6045 width. The second element of the result structure must be of
6046 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6047 undergo unsigned addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6048
6049<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6050<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6051 an unsigned addition of the two arguments. They return a structure &mdash;
6052 the first element of which is the sum, and the second element of which is a
6053 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6054
6055<h5>Examples:</h5>
6056<pre>
6057 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6058 %sum = extractvalue {i32, i1} %res, 0
6059 %obit = extractvalue {i32, i1} %res, 1
6060 br i1 %obit, label %carry, label %normal
6061</pre>
6062
6063</div>
6064
6065<!-- _______________________________________________________________________ -->
6066<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6067 <a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6068</div>
6069
6070<div class="doc_text">
6071
6072<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6073<p>This is an overloaded intrinsic. You can use <tt>llvm.ssub.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6074 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6075
6076<pre>
6077 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6078 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6079 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6080</pre>
6081
6082<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6083<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6084 a signed subtraction of the two arguments, and indicate whether an overflow
6085 occurred during the signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6086
6087<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6088<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6089 be of integer types of any bit width, but they must have the same bit
6090 width. The second element of the result structure must be of
6091 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6092 undergo signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6093
6094<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6095<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6096 a signed subtraction of the two arguments. They return a structure &mdash;
6097 the first element of which is the subtraction, and the second element of
6098 which is a bit specifying if the signed subtraction resulted in an
6099 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6100
6101<h5>Examples:</h5>
6102<pre>
6103 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6104 %sum = extractvalue {i32, i1} %res, 0
6105 %obit = extractvalue {i32, i1} %res, 1
6106 br i1 %obit, label %overflow, label %normal
6107</pre>
6108
6109</div>
6110
6111<!-- _______________________________________________________________________ -->
6112<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6113 <a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6114</div>
6115
6116<div class="doc_text">
6117
6118<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6119<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6120 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6121
6122<pre>
6123 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6124 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6125 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6126</pre>
6127
6128<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6129<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6130 an unsigned subtraction of the two arguments, and indicate whether an
6131 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6132
6133<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6134<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6135 be of integer types of any bit width, but they must have the same bit
6136 width. The second element of the result structure must be of
6137 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6138 undergo unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6139
6140<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6141<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6142 an unsigned subtraction of the two arguments. They return a structure &mdash;
6143 the first element of which is the subtraction, and the second element of
6144 which is a bit specifying if the unsigned subtraction resulted in an
6145 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6146
6147<h5>Examples:</h5>
6148<pre>
6149 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6150 %sum = extractvalue {i32, i1} %res, 0
6151 %obit = extractvalue {i32, i1} %res, 1
6152 br i1 %obit, label %overflow, label %normal
6153</pre>
6154
6155</div>
6156
6157<!-- _______________________________________________________________________ -->
6158<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6159 <a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6160</div>
6161
6162<div class="doc_text">
6163
6164<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6165<p>This is an overloaded intrinsic. You can use <tt>llvm.smul.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6166 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6167
6168<pre>
6169 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6170 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6171 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6172</pre>
6173
6174<h5>Overview:</h5>
6175
6176<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6177 a signed multiplication of the two arguments, and indicate whether an
6178 overflow occurred during the signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6179
6180<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6181<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6182 be of integer types of any bit width, but they must have the same bit
6183 width. The second element of the result structure must be of
6184 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6185 undergo signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6186
6187<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6188<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6189 a signed multiplication of the two arguments. They return a structure &mdash;
6190 the first element of which is the multiplication, and the second element of
6191 which is a bit specifying if the signed multiplication resulted in an
6192 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6193
6194<h5>Examples:</h5>
6195<pre>
6196 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6197 %sum = extractvalue {i32, i1} %res, 0
6198 %obit = extractvalue {i32, i1} %res, 1
6199 br i1 %obit, label %overflow, label %normal
6200</pre>
6201
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]6202</div>
6203
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6204<!-- _______________________________________________________________________ -->
6205<div class="doc_subsubsection">
6206 <a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
6207</div>
6208
6209<div class="doc_text">
6210
6211<h5>Syntax:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6212<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6213 on any integer bit width.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6214
6215<pre>
6216 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6217 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6218 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6219</pre>
6220
6221<h5>Overview:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6222<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6223 a unsigned multiplication of the two arguments, and indicate whether an
6224 overflow occurred during the unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6225
6226<h5>Arguments:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6227<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6228 be of integer types of any bit width, but they must have the same bit
6229 width. The second element of the result structure must be of
6230 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6231 undergo unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6232
6233<h5>Semantics:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6234<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6235 an unsigned multiplication of the two arguments. They return a structure
6236 &mdash; the first element of which is the multiplication, and the second
6237 element of which is a bit specifying if the unsigned multiplication resulted
6238 in an overflow.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6239
6240<h5>Examples:</h5>
6241<pre>
6242 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6243 %sum = extractvalue {i32, i1} %res, 0
6244 %obit = extractvalue {i32, i1} %res, 1
6245 br i1 %obit, label %overflow, label %normal
6246</pre>
6247
6248</div>
6249
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6250<!-- ======================================================================= -->
6251<div class="doc_subsection">
6252 <a name="int_debugger">Debugger Intrinsics</a>
6253</div>
6254
6255<div class="doc_text">
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6256
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6257<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
6258 prefix), are described in
6259 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
6260 Level Debugging</a> document.</p>
6261
6262</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6263
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6264<!-- ======================================================================= -->
6265<div class="doc_subsection">
6266 <a name="int_eh">Exception Handling Intrinsics</a>
6267</div>
6268
6269<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6270
6271<p>The LLVM exception handling intrinsics (which all start with
6272 <tt>llvm.eh.</tt> prefix), are described in
6273 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
6274 Handling</a> document.</p>
6275
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6276</div>
6277
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6278<!-- ======================================================================= -->
6279<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6280 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6281</div>
6282
6283<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6284
6285<p>This intrinsic makes it possible to excise one parameter, marked with
6286 the <tt>nest</tt> attribute, from a function. The result is a callable
6287 function pointer lacking the nest parameter - the caller does not need to
6288 provide a value for it. Instead, the value to use is stored in advance in a
6289 "trampoline", a block of memory usually allocated on the stack, which also
6290 contains code to splice the nest value into the argument list. This is used
6291 to implement the GCC nested function address extension.</p>
6292
6293<p>For example, if the function is
6294 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
6295 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
6296 follows:</p>
6297
6298<div class="doc_code">
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6299<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6300 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
6301 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
6302 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
6303 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6304</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6305</div>
6306
6307<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
6308 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
6309
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6310</div>
6311
6312<!-- _______________________________________________________________________ -->
6313<div class="doc_subsubsection">
6314 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
6315</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6316
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6317<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6318
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6319<h5>Syntax:</h5>
6320<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6321 declare 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]6322</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6323
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6324<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6325<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
6326 function pointer suitable for executing it.</p>
6327
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6328<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6329<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
6330 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
6331 sufficiently aligned block of memory; this memory is written to by the
6332 intrinsic. Note that the size and the alignment are target-specific - LLVM
6333 currently provides no portable way of determining them, so a front-end that
6334 generates this intrinsic needs to have some target-specific knowledge.
6335 The <tt>func</tt> argument must hold a function bitcast to
6336 an <tt>i8*</tt>.</p>
6337
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6338<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6339<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
6340 dependent code, turning it into a function. A pointer to this function is
6341 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
6342 function pointer type</a> before being called. The new function's signature
6343 is the same as that of <tt>func</tt> with any arguments marked with
6344 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
6345 is allowed, and it must be of pointer type. Calling the new function is
6346 equivalent to calling <tt>func</tt> with the same argument list, but
6347 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
6348 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
6349 by <tt>tramp</tt> is modified, then the effect of any later call to the
6350 returned function pointer is undefined.</p>
6351
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6352</div>
6353
6354<!-- ======================================================================= -->
6355<div class="doc_subsection">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6356 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
6357</div>
6358
6359<div class="doc_text">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6360
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6361<p>These intrinsic functions expand the "universal IR" of LLVM to represent
6362 hardware constructs for atomic operations and memory synchronization. This
6363 provides an interface to the hardware, not an interface to the programmer. It
6364 is aimed at a low enough level to allow any programming models or APIs
6365 (Application Programming Interfaces) which need atomic behaviors to map
6366 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
6367 hardware provides a "universal IR" for source languages, it also provides a
6368 starting point for developing a "universal" atomic operation and
6369 synchronization IR.</p>
6370
6371<p>These do <em>not</em> form an API such as high-level threading libraries,
6372 software transaction memory systems, atomic primitives, and intrinsic
6373 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
6374 application libraries. The hardware interface provided by LLVM should allow
6375 a clean implementation of all of these APIs and parallel programming models.
6376 No one model or paradigm should be selected above others unless the hardware
6377 itself ubiquitously does so.</p>
6378
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6379</div>
6380
6381<!-- _______________________________________________________________________ -->
6382<div class="doc_subsubsection">
6383 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
6384</div>
6385<div class="doc_text">
6386<h5>Syntax:</h5>
6387<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6388 declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;, i1 &lt;device&gt; )
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6389</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6390
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6391<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6392<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
6393 specific pairs of memory access types.</p>
6394
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6395<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6396<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
6397 The first four arguments enables a specific barrier as listed below. The
6398 fith argument specifies that the barrier applies to io or device or uncached
6399 memory.</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6400
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6401<ul>
6402 <li><tt>ll</tt>: load-load barrier</li>
6403 <li><tt>ls</tt>: load-store barrier</li>
6404 <li><tt>sl</tt>: store-load barrier</li>
6405 <li><tt>ss</tt>: store-store barrier</li>
6406 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
6407</ul>
6408
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6409<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6410<p>This intrinsic causes the system to enforce some ordering constraints upon
6411 the loads and stores of the program. This barrier does not
6412 indicate <em>when</em> any events will occur, it only enforces
6413 an <em>order</em> in which they occur. For any of the specified pairs of load
6414 and store operations (f.ex. load-load, or store-load), all of the first
6415 operations preceding the barrier will complete before any of the second
6416 operations succeeding the barrier begin. Specifically the semantics for each
6417 pairing is as follows:</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6418
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6419<ul>
6420 <li><tt>ll</tt>: All loads before the barrier must complete before any load
6421 after the barrier begins.</li>
6422 <li><tt>ls</tt>: All loads before the barrier must complete before any
6423 store after the barrier begins.</li>
6424 <li><tt>ss</tt>: All stores before the barrier must complete before any
6425 store after the barrier begins.</li>
6426 <li><tt>sl</tt>: All stores before the barrier must complete before any
6427 load after the barrier begins.</li>
6428</ul>
6429
6430<p>These semantics are applied with a logical "and" behavior when more than one
6431 is enabled in a single memory barrier intrinsic.</p>
6432
6433<p>Backends may implement stronger barriers than those requested when they do
6434 not support as fine grained a barrier as requested. Some architectures do
6435 not need all types of barriers and on such architectures, these become
6436 noops.</p>
6437
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6438<h5>Example:</h5>
6439<pre>
6440%ptr = malloc i32
6441 store i32 4, %ptr
6442
6443%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
6444 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
6445 <i>; guarantee the above finishes</i>
6446 store i32 8, %ptr <i>; before this begins</i>
6447</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6448
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6449</div>
6450
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6451<!-- _______________________________________________________________________ -->
6452<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6453 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6454</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6455
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6456<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6457
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6458<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6459<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
6460 any integer bit width and for different address spaces. Not all targets
6461 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6462
6463<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6464 declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6465 declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6466 declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
6467 declare 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]6468</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6469
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6470<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6471<p>This loads a value in memory and compares it to a given value. If they are
6472 equal, it stores a new value into the memory.</p>
6473
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6474<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6475<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
6476 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
6477 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
6478 this integer type. While any bit width integer may be used, targets may only
6479 lower representations they support in hardware.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6480
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6481<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6482<p>This entire intrinsic must be executed atomically. It first loads the value
6483 in memory pointed to by <tt>ptr</tt> and compares it with the
6484 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
6485 memory. The loaded value is yielded in all cases. This provides the
6486 equivalent of an atomic compare-and-swap operation within the SSA
6487 framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6488
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6489<h5>Examples:</h5>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6490<pre>
6491%ptr = malloc i32
6492 store i32 4, %ptr
6493
6494%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6495%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6496 <i>; yields {i32}:result1 = 4</i>
6497%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6498%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6499
6500%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6501%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6502 <i>; yields {i32}:result2 = 8</i>
6503%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6504
6505%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6506</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6507
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6508</div>
6509
6510<!-- _______________________________________________________________________ -->
6511<div class="doc_subsubsection">
6512 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6513</div>
6514<div class="doc_text">
6515<h5>Syntax:</h5>
6516
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6517<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6518 integer bit width. Not all targets support all bit widths however.</p>
6519
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6520<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6521 declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6522 declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6523 declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6524 declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6525</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6526
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6527<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6528<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6529 the value from memory. It then stores the value in <tt>val</tt> in the memory
6530 at <tt>ptr</tt>.</p>
6531
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6532<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6533<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
6534 the <tt>val</tt> argument and the result must be integers of the same bit
6535 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6536 integer type. The targets may only lower integer representations they
6537 support.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6538
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6539<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6540<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6541 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6542 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6543
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6544<h5>Examples:</h5>
6545<pre>
6546%ptr = malloc i32
6547 store i32 4, %ptr
6548
6549%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6550%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6551 <i>; yields {i32}:result1 = 4</i>
6552%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6553%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6554
6555%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6556%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6557 <i>; yields {i32}:result2 = 8</i>
6558
6559%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6560%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6561</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6562
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6563</div>
6564
6565<!-- _______________________________________________________________________ -->
6566<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6567 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6568
6569</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6570
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6571<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6572
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6573<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6574<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
6575 any integer bit width. Not all targets support all bit widths however.</p>
6576
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6577<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6578 declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6579 declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6580 declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6581 declare 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]6582</pre>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6583
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6584<h5>Overview:</h5>
6585<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
6586 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6587
6588<h5>Arguments:</h5>
6589<p>The intrinsic takes two arguments, the first a pointer to an integer value
6590 and the second an integer value. The result is also an integer value. These
6591 integer types can have any bit width, but they must all have the same bit
6592 width. The targets may only lower integer representations they support.</p>
6593
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6594<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6595<p>This intrinsic does a series of operations atomically. It first loads the
6596 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6597 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6598
6599<h5>Examples:</h5>
6600<pre>
6601%ptr = malloc i32
6602 store i32 4, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6603%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6604 <i>; yields {i32}:result1 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6605%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6606 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6607%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6608 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6609%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6610</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6611
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6612</div>
6613
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6614<!-- _______________________________________________________________________ -->
6615<div class="doc_subsubsection">
6616 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6617
6618</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6619
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6620<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6621
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6622<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6623<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
6624 any integer bit width and for different address spaces. Not all targets
6625 support all bit widths however.</p>
6626
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6627<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6628 declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6629 declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6630 declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6631 declare 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]6632</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6633
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6634<h5>Overview:</h5>
6635<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6636 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6637
6638<h5>Arguments:</h5>
6639<p>The intrinsic takes two arguments, the first a pointer to an integer value
6640 and the second an integer value. The result is also an integer value. These
6641 integer types can have any bit width, but they must all have the same bit
6642 width. The targets may only lower integer representations they support.</p>
6643
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6644<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6645<p>This intrinsic does a series of operations atomically. It first loads the
6646 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6647 result to <tt>ptr</tt>. It yields the original value stored
6648 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6649
6650<h5>Examples:</h5>
6651<pre>
6652%ptr = malloc i32
6653 store i32 8, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6654%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6655 <i>; yields {i32}:result1 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6656%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6657 <i>; yields {i32}:result2 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6658%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6659 <i>; yields {i32}:result3 = 2</i>
6660%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6661</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6662
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6663</div>
6664
6665<!-- _______________________________________________________________________ -->
6666<div class="doc_subsubsection">
6667 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6668 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6669 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6670 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6671</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6672
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6673<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6674
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6675<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6676<p>These are overloaded intrinsics. You can
6677 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
6678 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
6679 bit width and for different address spaces. Not all targets support all bit
6680 widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6681
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6682<pre>
6683 declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6684 declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6685 declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6686 declare 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]6687</pre>
6688
6689<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6690 declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6691 declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6692 declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6693 declare 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]6694</pre>
6695
6696<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6697 declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6698 declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6699 declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6700 declare 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]6701</pre>
6702
6703<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6704 declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6705 declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6706 declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6707 declare 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]6708</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6709
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6710<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6711<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6712 the value stored in memory at <tt>ptr</tt>. It yields the original value
6713 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6714
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6715<h5>Arguments:</h5>
6716<p>These intrinsics take two arguments, the first a pointer to an integer value
6717 and the second an integer value. The result is also an integer value. These
6718 integer types can have any bit width, but they must all have the same bit
6719 width. The targets may only lower integer representations they support.</p>
6720
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6721<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6722<p>These intrinsics does a series of operations atomically. They first load the
6723 value stored at <tt>ptr</tt>. They then do the bitwise
6724 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
6725 original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6726
6727<h5>Examples:</h5>
6728<pre>
6729%ptr = malloc i32
6730 store i32 0x0F0F, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6731%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6732 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6733%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6734 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6735%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6736 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6737%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6738 <i>; yields {i32}:result3 = FF</i>
6739%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6740</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6741
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6742</div>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6743
6744<!-- _______________________________________________________________________ -->
6745<div class="doc_subsubsection">
6746 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6747 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6748 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6749 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6750</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6751
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6752<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6753
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6754<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6755<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6756 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
6757 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6758 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6759
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6760<pre>
6761 declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6762 declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6763 declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6764 declare 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]6765</pre>
6766
6767<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6768 declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6769 declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6770 declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6771 declare 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]6772</pre>
6773
6774<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6775 declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6776 declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6777 declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6778 declare 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]6779</pre>
6780
6781<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6782 declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6783 declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6784 declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6785 declare 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]6786</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6787
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6788<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6789<p>These intrinsics takes the signed or unsigned minimum or maximum of
6790 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6791 original value at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6792
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6793<h5>Arguments:</h5>
6794<p>These intrinsics take two arguments, the first a pointer to an integer value
6795 and the second an integer value. The result is also an integer value. These
6796 integer types can have any bit width, but they must all have the same bit
6797 width. The targets may only lower integer representations they support.</p>
6798
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6799<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6800<p>These intrinsics does a series of operations atomically. They first load the
6801 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
6802 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
6803 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6804
6805<h5>Examples:</h5>
6806<pre>
6807%ptr = malloc i32
6808 store i32 7, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6809%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6810 <i>; yields {i32}:result0 = 7</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6811%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6812 <i>; yields {i32}:result1 = -2</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6813%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6814 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6815%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6816 <i>; yields {i32}:result3 = 8</i>
6817%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6818</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6819
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6820</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6821
6822<!-- ======================================================================= -->
6823<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6824 <a name="int_general">General Intrinsics</a>
6825</div>
6826
6827<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6828
6829<p>This class of intrinsics is designed to be generic and has no specific
6830 purpose.</p>
6831
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6832</div>
6833
6834<!-- _______________________________________________________________________ -->
6835<div class="doc_subsubsection">
6836 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6837</div>
6838
6839<div class="doc_text">
6840
6841<h5>Syntax:</h5>
6842<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]6843 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]6844</pre>
6845
6846<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6847<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6848
6849<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6850<p>The first argument is a pointer to a value, the second is a pointer to a
6851 global string, the third is a pointer to a global string which is the source
6852 file name, and the last argument is the line number.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6853
6854<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6855<p>This intrinsic allows annotation of local variables with arbitrary strings.
6856 This can be useful for special purpose optimizations that want to look for
6857 these annotations. These have no other defined use, they are ignored by code
6858 generation and optimization.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6859
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6860</div>
6861
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6862<!-- _______________________________________________________________________ -->
6863<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]6864 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6865</div>
6866
6867<div class="doc_text">
6868
6869<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6870<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6871 any integer bit width.</p>
6872
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6873<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]6874 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6875 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6876 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6877 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6878 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]6879</pre>
6880
6881<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6882<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6883
6884<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6885<p>The first argument is an integer value (result of some expression), the
6886 second is a pointer to a global string, the third is a pointer to a global
6887 string which is the source file name, and the last argument is the line
6888 number. It returns the value of the first argument.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6889
6890<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6891<p>This intrinsic allows annotations to be put on arbitrary expressions with
6892 arbitrary strings. This can be useful for special purpose optimizations that
6893 want to look for these annotations. These have no other defined use, they
6894 are ignored by code generation and optimization.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6895
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6896</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6897
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6898<!-- _______________________________________________________________________ -->
6899<div class="doc_subsubsection">
6900 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6901</div>
6902
6903<div class="doc_text">
6904
6905<h5>Syntax:</h5>
6906<pre>
6907 declare void @llvm.trap()
6908</pre>
6909
6910<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6911<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6912
6913<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6914<p>None.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6915
6916<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6917<p>This intrinsics is lowered to the target dependent trap instruction. If the
6918 target does not have a trap instruction, this intrinsic will be lowered to
6919 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6920
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6921</div>
6922
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6923<!-- _______________________________________________________________________ -->
6924<div class="doc_subsubsection">
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]6925 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6926</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6927
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6928<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6929
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6930<h5>Syntax:</h5>
6931<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6932 declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6933</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6934
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6935<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6936<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
6937 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
6938 ensure that it is placed on the stack before local variables.</p>
6939
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6940<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6941<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
6942 arguments. The first argument is the value loaded from the stack
6943 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
6944 that has enough space to hold the value of the guard.</p>
6945
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6946<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6947<p>This intrinsic causes the prologue/epilogue inserter to force the position of
6948 the <tt>AllocaInst</tt> stack slot to be before local variables on the
6949 stack. This is to ensure that if a local variable on the stack is
6950 overwritten, it will destroy the value of the guard. When the function exits,
6951 the guard on the stack is checked against the original guard. If they're
6952 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
6953 function.</p>
6954
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6955</div>
6956
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6957<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6958<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6959<address>
6960 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]6961 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6962 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]6963 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]6964
6965 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]6966 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6967 Last modified: $Date$
6968</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]6969
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6970</body>
6971</html>