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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / cd81f5df27c9a47561be1b9a4059ca3a5dcace4c / . / 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
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]555 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]556 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
557 <tt>linkonce</tt> linkage, except that unreferenced globals with
558 <tt>weak</tt> linkage may not be discarded. This is used for globals that
559 are declared "weak" in C source code.</dd>
560
561 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
562 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
563 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
564 global scope.
565 Symbols with "<tt>common</tt>" linkage are merged in the same way as
566 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame^]567 <tt>common</tt> symbols may not have an explicit section,
568 must have a zero initializer, and may not be marked '<a
569 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
570 have common linkage.</dd>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]571
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]572
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]573 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]574 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]575 pointer to array type. When two global variables with appending linkage
576 are linked together, the two global arrays are appended together. This is
577 the LLVM, typesafe, equivalent of having the system linker append together
578 "sections" with identical names when .o files are linked.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]579
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]580 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]581 <dd>The semantics of this linkage follow the ELF object file model: the symbol
582 is weak until linked, if not linked, the symbol becomes null instead of
583 being an undefined reference.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]584
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]585 <dt><tt><b><a name="linkage_linkonce">linkonce_odr</a></b></tt>: </dt>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]586 <dt><tt><b><a name="linkage_weak">weak_odr</a></b></tt>: </dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]587 <dd>Some languages allow differing globals to be merged, such as two functions
588 with different semantics. Other languages, such as <tt>C++</tt>, ensure
589 that only equivalent globals are ever merged (the "one definition rule" -
590 "ODR"). Such languages can use the <tt>linkonce_odr</tt>
591 and <tt>weak_odr</tt> linkage types to indicate that the global will only
592 be merged with equivalent globals. These linkage types are otherwise the
593 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]594
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]595 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]596 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]597 visible, meaning that it participates in linkage and can be used to
598 resolve external symbol references.</dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]599</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]600
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]601<p>The next two types of linkage are targeted for Microsoft Windows platform
602 only. They are designed to support importing (exporting) symbols from (to)
603 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]604
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]605<dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]606 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]607 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]608 or variable via a global pointer to a pointer that is set up by the DLL
609 exporting the symbol. On Microsoft Windows targets, the pointer name is
610 formed by combining <code>__imp_</code> and the function or variable
611 name.</dd>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]612
613 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]614 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]615 pointer to a pointer in a DLL, so that it can be referenced with the
616 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
617 name is formed by combining <code>__imp_</code> and the function or
618 variable name.</dd>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]619</dl>
620
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]621<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
622 another module defined a "<tt>.LC0</tt>" variable and was linked with this
623 one, one of the two would be renamed, preventing a collision. Since
624 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
625 declarations), they are accessible outside of the current module.</p>
626
627<p>It is illegal for a function <i>declaration</i> to have any linkage type
628 other than "externally visible", <tt>dllimport</tt>
629 or <tt>extern_weak</tt>.</p>
630
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]631<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]632 or <tt>weak_odr</tt> linkages.</p>
633
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]634</div>
635
636<!-- ======================================================================= -->
637<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]638 <a name="callingconv">Calling Conventions</a>
639</div>
640
641<div class="doc_text">
642
643<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]644 and <a href="#i_invoke">invokes</a> can all have an optional calling
645 convention specified for the call. The calling convention of any pair of
646 dynamic caller/callee must match, or the behavior of the program is
647 undefined. The following calling conventions are supported by LLVM, and more
648 may be added in the future:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]649
650<dl>
651 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]652 <dd>This calling convention (the default if no other calling convention is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]653 specified) matches the target C calling conventions. This calling
654 convention supports varargs function calls and tolerates some mismatch in
655 the declared prototype and implemented declaration of the function (as
656 does normal C).</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]657
658 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]659 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]660 (e.g. by passing things in registers). This calling convention allows the
661 target to use whatever tricks it wants to produce fast code for the
662 target, without having to conform to an externally specified ABI
663 (Application Binary Interface). Implementations of this convention should
664 allow arbitrary <a href="CodeGenerator.html#tailcallopt">tail call
665 optimization</a> to be supported. This calling convention does not
666 support varargs and requires the prototype of all callees to exactly match
667 the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]668
669 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]670 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]671 as possible under the assumption that the call is not commonly executed.
672 As such, these calls often preserve all registers so that the call does
673 not break any live ranges in the caller side. This calling convention
674 does not support varargs and requires the prototype of all callees to
675 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]676
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]677 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]678 <dd>Any calling convention may be specified by number, allowing
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]679 target-specific calling conventions to be used. Target specific calling
680 conventions start at 64.</dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]681</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]682
683<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]684 support Pascal conventions or any other well-known target-independent
685 convention.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]686
687</div>
688
689<!-- ======================================================================= -->
690<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]691 <a name="visibility">Visibility Styles</a>
692</div>
693
694<div class="doc_text">
695
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]696<p>All Global Variables and Functions have one of the following visibility
697 styles:</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]698
699<dl>
700 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]701 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]702 that the declaration is visible to other modules and, in shared libraries,
703 means that the declared entity may be overridden. On Darwin, default
704 visibility means that the declaration is visible to other modules. Default
705 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]706
707 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]708 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]709 object if they are in the same shared object. Usually, hidden visibility
710 indicates that the symbol will not be placed into the dynamic symbol
711 table, so no other module (executable or shared library) can reference it
712 directly.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]713
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]714 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]715 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]716 the dynamic symbol table, but that references within the defining module
717 will bind to the local symbol. That is, the symbol cannot be overridden by
718 another module.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]719</dl>
720
721</div>
722
723<!-- ======================================================================= -->
724<div class="doc_subsection">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]725 <a name="namedtypes">Named Types</a>
726</div>
727
728<div class="doc_text">
729
730<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]731 it easier to read the IR and make the IR more condensed (particularly when
732 recursive types are involved). An example of a name specification is:</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]733
734<div class="doc_code">
735<pre>
736%mytype = type { %mytype*, i32 }
737</pre>
738</div>
739
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]740<p>You may give a name to any <a href="#typesystem">type</a> except
741 "<a href="t_void">void</a>". Type name aliases may be used anywhere a type
742 is expected with the syntax "%mytype".</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]743
744<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]745 and that you can therefore specify multiple names for the same type. This
746 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
747 uses structural typing, the name is not part of the type. When printing out
748 LLVM IR, the printer will pick <em>one name</em> to render all types of a
749 particular shape. This means that if you have code where two different
750 source types end up having the same LLVM type, that the dumper will sometimes
751 print the "wrong" or unexpected type. This is an important design point and
752 isn't going to change.</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]753
754</div>
755
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]756<!-- ======================================================================= -->
757<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]758 <a name="globalvars">Global Variables</a>
759</div>
760
761<div class="doc_text">
762
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]763<p>Global variables define regions of memory allocated at compilation time
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]764 instead of run-time. Global variables may optionally be initialized, may
765 have an explicit section to be placed in, and may have an optional explicit
766 alignment specified. A variable may be defined as "thread_local", which
767 means that it will not be shared by threads (each thread will have a
768 separated copy of the variable). A variable may be defined as a global
769 "constant," which indicates that the contents of the variable
770 will <b>never</b> be modified (enabling better optimization, allowing the
771 global data to be placed in the read-only section of an executable, etc).
772 Note that variables that need runtime initialization cannot be marked
773 "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]774
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]775<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
776 constant, even if the final definition of the global is not. This capability
777 can be used to enable slightly better optimization of the program, but
778 requires the language definition to guarantee that optimizations based on the
779 'constantness' are valid for the translation units that do not include the
780 definition.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]781
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]782<p>As SSA values, global variables define pointer values that are in scope
783 (i.e. they dominate) all basic blocks in the program. Global variables
784 always define a pointer to their "content" type because they describe a
785 region of memory, and all memory objects in LLVM are accessed through
786 pointers.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]787
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]788<p>A global variable may be declared to reside in a target-specific numbered
789 address space. For targets that support them, address spaces may affect how
790 optimizations are performed and/or what target instructions are used to
791 access the variable. The default address space is zero. The address space
792 qualifier must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]793
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]794<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]795 supports it, it will emit globals to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]796
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]797<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]798 the alignment is set to zero, the alignment of the global is set by the
799 target to whatever it feels convenient. If an explicit alignment is
800 specified, the global is forced to have at least that much alignment. All
801 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]802
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]803<p>For example, the following defines a global in a numbered address space with
804 an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]805
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]806<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]807<pre>
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]808@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]809</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]810</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]811
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]812</div>
813
814
815<!-- ======================================================================= -->
816<div class="doc_subsection">
817 <a name="functionstructure">Functions</a>
818</div>
819
820<div class="doc_text">
821
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]822<p>LLVM function definitions consist of the "<tt>define</tt>" keyord, an
823 optional <a href="#linkage">linkage type</a>, an optional
824 <a href="#visibility">visibility style</a>, an optional
825 <a href="#callingconv">calling convention</a>, a return type, an optional
826 <a href="#paramattrs">parameter attribute</a> for the return type, a function
827 name, a (possibly empty) argument list (each with optional
828 <a href="#paramattrs">parameter attributes</a>), optional
829 <a href="#fnattrs">function attributes</a>, an optional section, an optional
830 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
831 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]832
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]833<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
834 optional <a href="#linkage">linkage type</a>, an optional
835 <a href="#visibility">visibility style</a>, an optional
836 <a href="#callingconv">calling convention</a>, a return type, an optional
837 <a href="#paramattrs">parameter attribute</a> for the return type, a function
838 name, a possibly empty list of arguments, an optional alignment, and an
839 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]840
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]841<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]842 (Control Flow Graph) for the function. Each basic block may optionally start
843 with a label (giving the basic block a symbol table entry), contains a list
844 of instructions, and ends with a <a href="#terminators">terminator</a>
845 instruction (such as a branch or function return).</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]846
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]847<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]848 executed on entrance to the function, and it is not allowed to have
849 predecessor basic blocks (i.e. there can not be any branches to the entry
850 block of a function). Because the block can have no predecessors, it also
851 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]852
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]853<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]854 supports it, it will emit functions to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]855
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]856<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]857 the alignment is set to zero, the alignment of the function is set by the
858 target to whatever it feels convenient. If an explicit alignment is
859 specified, the function is forced to have at least that much alignment. All
860 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]861
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]862<h5>Syntax:</h5>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]863<div class="doc_code">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]864<pre>
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]865define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]866 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
867 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
868 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
869 [<a href="#gc">gc</a>] { ... }
870</pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]871</div>
872
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]873</div>
874
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]875<!-- ======================================================================= -->
876<div class="doc_subsection">
877 <a name="aliasstructure">Aliases</a>
878</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]879
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]880<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]881
882<p>Aliases act as "second name" for the aliasee value (which can be either
883 function, global variable, another alias or bitcast of global value). Aliases
884 may have an optional <a href="#linkage">linkage type</a>, and an
885 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]886
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]887<h5>Syntax:</h5>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]888<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]889<pre>
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]890@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]891</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]892</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]893
894</div>
895
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]896<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]897<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]898
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]899<div class="doc_text">
900
901<p>The return type and each parameter of a function type may have a set of
902 <i>parameter attributes</i> associated with them. Parameter attributes are
903 used to communicate additional information about the result or parameters of
904 a function. Parameter attributes are considered to be part of the function,
905 not of the function type, so functions with different parameter attributes
906 can have the same function type.</p>
907
908<p>Parameter attributes are simple keywords that follow the type specified. If
909 multiple parameter attributes are needed, they are space separated. For
910 example:</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]911
912<div class="doc_code">
913<pre>
Nick Lewyckyb6a7d252009-02-15 23:06:14 +0000[diff] [blame]914declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]915declare i32 @atoi(i8 zeroext)
916declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]917</pre>
918</div>
919
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]920<p>Note that any attributes for the function result (<tt>nounwind</tt>,
921 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]922
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]923<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]924
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]925<dl>
926 <dt><tt>zeroext</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]927 <dd>This indicates to the code generator that the parameter or return value
928 should be zero-extended to a 32-bit value by the caller (for a parameter)
929 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]930
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]931 <dt><tt>signext</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]932 <dd>This indicates to the code generator that the parameter or return value
933 should be sign-extended to a 32-bit value by the caller (for a parameter)
934 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]935
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]936 <dt><tt>inreg</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]937 <dd>This indicates that this parameter or return value should be treated in a
938 special target-dependent fashion during while emitting code for a function
939 call or return (usually, by putting it in a register as opposed to memory,
940 though some targets use it to distinguish between two different kinds of
941 registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]942
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]943 <dt><tt><a name="byval">byval</a></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]944 <dd>This indicates that the pointer parameter should really be passed by value
945 to the function. The attribute implies that a hidden copy of the pointee
946 is made between the caller and the callee, so the callee is unable to
947 modify the value in the callee. This attribute is only valid on LLVM
948 pointer arguments. It is generally used to pass structs and arrays by
949 value, but is also valid on pointers to scalars. The copy is considered
950 to belong to the caller not the callee (for example,
951 <tt><a href="#readonly">readonly</a></tt> functions should not write to
952 <tt>byval</tt> parameters). This is not a valid attribute for return
953 values. The byval attribute also supports specifying an alignment with
954 the align attribute. This has a target-specific effect on the code
955 generator that usually indicates a desired alignment for the synthesized
956 stack slot.</dd>
957
958 <dt><tt>sret</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]959 <dd>This indicates that the pointer parameter specifies the address of a
960 structure that is the return value of the function in the source program.
961 This pointer must be guaranteed by the caller to be valid: loads and
962 stores to the structure may be assumed by the callee to not to trap. This
963 may only be applied to the first parameter. This is not a valid attribute
964 for return values. </dd>
965
966 <dt><tt>noalias</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]967 <dd>This indicates that the pointer does not alias any global or any other
968 parameter. The caller is responsible for ensuring that this is the
969 case. On a function return value, <tt>noalias</tt> additionally indicates
970 that the pointer does not alias any other pointers visible to the
971 caller. For further details, please see the discussion of the NoAlias
972 response in
973 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
974 analysis</a>.</dd>
975
976 <dt><tt>nocapture</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]977 <dd>This indicates that the callee does not make any copies of the pointer
978 that outlive the callee itself. This is not a valid attribute for return
979 values.</dd>
980
981 <dt><tt>nest</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]982 <dd>This indicates that the pointer parameter can be excised using the
983 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
984 attribute for return values.</dd>
985</dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]986
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]987</div>
988
989<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]990<div class="doc_subsection">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]991 <a name="gc">Garbage Collector Names</a>
992</div>
993
994<div class="doc_text">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]995
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]996<p>Each function may specify a garbage collector name, which is simply a
997 string:</p>
998
999<div class="doc_code">
1000<pre>
1001define void @f() gc "name" { ...
1002</pre>
1003</div>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1004
1005<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1006 collector which will cause the compiler to alter its output in order to
1007 support the named garbage collection algorithm.</p>
1008
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1009</div>
1010
1011<!-- ======================================================================= -->
1012<div class="doc_subsection">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1013 <a name="fnattrs">Function Attributes</a>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1014</div>
1015
1016<div class="doc_text">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1017
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1018<p>Function attributes are set to communicate additional information about a
1019 function. Function attributes are considered to be part of the function, not
1020 of the function type, so functions with different parameter attributes can
1021 have the same function type.</p>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1022
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1023<p>Function attributes are simple keywords that follow the type specified. If
1024 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1025
1026<div class="doc_code">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1027<pre>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1028define void @f() noinline { ... }
1029define void @f() alwaysinline { ... }
1030define void @f() alwaysinline optsize { ... }
1031define void @f() optsize
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1032</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1033</div>
1034
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1035<dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1036 <dt><tt>alwaysinline</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1037 <dd>This attribute indicates that the inliner should attempt to inline this
1038 function into callers whenever possible, ignoring any active inlining size
1039 threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1040
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1041 <dt><tt>noinline</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1042 <dd>This attribute indicates that the inliner should never inline this
1043 function in any situation. This attribute may not be used together with
1044 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1045
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1046 <dt><tt>optsize</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1047 <dd>This attribute suggests that optimization passes and code generator passes
1048 make choices that keep the code size of this function low, and otherwise
1049 do optimizations specifically to reduce code size.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1050
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1051 <dt><tt>noreturn</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1052 <dd>This function attribute indicates that the function never returns
1053 normally. This produces undefined behavior at runtime if the function
1054 ever does dynamically return.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1055
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1056 <dt><tt>nounwind</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1057 <dd>This function attribute indicates that the function never returns with an
1058 unwind or exceptional control flow. If the function does unwind, its
1059 runtime behavior is undefined.</dd>
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1060
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1061 <dt><tt>readnone</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1062 <dd>This attribute indicates that the function computes its result (or decides
1063 to unwind an exception) based strictly on its arguments, without
1064 dereferencing any pointer arguments or otherwise accessing any mutable
1065 state (e.g. memory, control registers, etc) visible to caller functions.
1066 It does not write through any pointer arguments
1067 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1068 changes any state visible to callers. This means that it cannot unwind
1069 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1070 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel5d96fda2009-06-12 19:45:19 +0000[diff] [blame]1071
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1072 <dt><tt><a name="readonly">readonly</a></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1073 <dd>This attribute indicates that the function does not write through any
1074 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1075 arguments) or otherwise modify any state (e.g. memory, control registers,
1076 etc) visible to caller functions. It may dereference pointer arguments
1077 and read state that may be set in the caller. A readonly function always
1078 returns the same value (or unwinds an exception identically) when called
1079 with the same set of arguments and global state. It cannot unwind an
1080 exception by calling the <tt>C++</tt> exception throwing methods, but may
1081 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc5ec8a72009-07-17 18:07:26 +0000[diff] [blame]1082
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1083 <dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1084 <dd>This attribute indicates that the function should emit a stack smashing
1085 protector. It is in the form of a "canary"&mdash;a random value placed on
1086 the stack before the local variables that's checked upon return from the
1087 function to see if it has been overwritten. A heuristic is used to
1088 determine if a function needs stack protectors or not.<br>
1089<br>
1090 If a function that has an <tt>ssp</tt> attribute is inlined into a
1091 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1092 function will have an <tt>ssp</tt> attribute.</dd>
1093
1094 <dt><tt>sspreq</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1095 <dd>This attribute indicates that the function should <em>always</em> emit a
1096 stack smashing protector. This overrides
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1097 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1098<br>
1099 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1100 function that doesn't have an <tt>sspreq</tt> attribute or which has
1101 an <tt>ssp</tt> attribute, then the resulting function will have
1102 an <tt>sspreq</tt> attribute.</dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1103
1104 <dt><tt>noredzone</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1105 <dd>This attribute indicates that the code generator should not use a red
1106 zone, even if the target-specific ABI normally permits it.</dd>
1107
1108 <dt><tt>noimplicitfloat</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1109 <dd>This attributes disables implicit floating point instructions.</dd>
1110
1111 <dt><tt>naked</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1112 <dd>This attribute disables prologue / epilogue emission for the function.
1113 This can have very system-specific consequences.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1114</dl>
1115
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1116</div>
1117
1118<!-- ======================================================================= -->
1119<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1120 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1121</div>
1122
1123<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1124
1125<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1126 the GCC "file scope inline asm" blocks. These blocks are internally
1127 concatenated by LLVM and treated as a single unit, but may be separated in
1128 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1129
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1130<div class="doc_code">
1131<pre>
1132module asm "inline asm code goes here"
1133module asm "more can go here"
1134</pre>
1135</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1136
1137<p>The strings can contain any character by escaping non-printable characters.
1138 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]1139 for the number.</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1140
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1141<p>The inline asm code is simply printed to the machine code .s file when
1142 assembly code is generated.</p>
1143
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1144</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1145
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1146<!-- ======================================================================= -->
1147<div class="doc_subsection">
1148 <a name="datalayout">Data Layout</a>
1149</div>
1150
1151<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1152
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1153<p>A module may specify a target specific data layout string that specifies how
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1154 data is to be laid out in memory. The syntax for the data layout is
1155 simply:</p>
1156
1157<div class="doc_code">
1158<pre>
1159target datalayout = "<i>layout specification</i>"
1160</pre>
1161</div>
1162
1163<p>The <i>layout specification</i> consists of a list of specifications
1164 separated by the minus sign character ('-'). Each specification starts with
1165 a letter and may include other information after the letter to define some
1166 aspect of the data layout. The specifications accepted are as follows:</p>
1167
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1168<dl>
1169 <dt><tt>E</tt></dt>
1170 <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]1171 bits with the most significance have the lowest address location.</dd>
1172
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1173 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1174 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1175 the bits with the least significance have the lowest address
1176 location.</dd>
1177
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1178 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1179 <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]1180 <i>preferred</i> alignments. All sizes are in bits. Specifying
1181 the <i>pref</i> alignment is optional. If omitted, the
1182 preceding <tt>:</tt> should be omitted too.</dd>
1183
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1184 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1185 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1186 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1187
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1188 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1189 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1190 <i>size</i>.</dd>
1191
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1192 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1193 <dd>This specifies the alignment for a floating point type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1194 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1195 (double).</dd>
1196
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1197 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1198 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1199 <i>size</i>.</dd>
1200
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1201 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1202 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1203 <i>size</i>.</dd>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1204</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1205
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1206<p>When constructing the data layout for a given target, LLVM starts with a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1207 default set of specifications which are then (possibly) overriden by the
1208 specifications in the <tt>datalayout</tt> keyword. The default specifications
1209 are given in this list:</p>
1210
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1211<ul>
1212 <li><tt>E</tt> - big endian</li>
1213 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1214 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1215 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1216 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1217 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1218 <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]1219 alignment of 64-bits</li>
1220 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1221 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1222 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1223 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1224 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1225 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1226</ul>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1227
1228<p>When LLVM is determining the alignment for a given type, it uses the
1229 following rules:</p>
1230
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1231<ol>
1232 <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]1233 specification is used.</li>
1234
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1235 <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]1236 smallest integer type that is larger than the bitwidth of the sought type
1237 is used. If none of the specifications are larger than the bitwidth then
1238 the the largest integer type is used. For example, given the default
1239 specifications above, the i7 type will use the alignment of i8 (next
1240 largest) while both i65 and i256 will use the alignment of i64 (largest
1241 specified).</li>
1242
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1243 <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]1244 largest vector type that is smaller than the sought vector type will be
1245 used as a fall back. This happens because &lt;128 x double&gt; can be
1246 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1247</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1248
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1249</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1250
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1251<!-- ======================================================================= -->
1252<div class="doc_subsection">
1253 <a name="pointeraliasing">Pointer Aliasing Rules</a>
1254</div>
1255
1256<div class="doc_text">
1257
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1258<p>Any memory access must be done through a pointer value associated
Andreas Bolka99a82052009-07-27 20:37:10 +0000[diff] [blame]1259with an address range of the memory access, otherwise the behavior
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1260is undefined. Pointer values are associated with address ranges
1261according to the following rules:</p>
1262
1263<ul>
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1264 <li>A pointer value formed from a
1265 <tt><a href="#i_getelementptr">getelementptr</a></tt> instruction
1266 is associated with the addresses associated with the first operand
1267 of the <tt>getelementptr</tt>.</li>
1268 <li>An address of a global variable is associated with the address
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1269 range of the variable's storage.</li>
1270 <li>The result value of an allocation instruction is associated with
1271 the address range of the allocated storage.</li>
1272 <li>A null pointer in the default address-space is associated with
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1273 no address.</li>
1274 <li>A pointer value formed by an
1275 <tt><a href="#i_inttoptr">inttoptr</a></tt> is associated with all
1276 address ranges of all pointer values that contribute (directly or
1277 indirectly) to the computation of the pointer's value.</li>
1278 <li>The result value of a
1279 <tt><a href="#i_bitcast">bitcast</a></tt> is associated with all
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1280 addresses associated with the operand of the <tt>bitcast</tt>.</li>
1281 <li>An integer constant other than zero or a pointer value returned
1282 from a function not defined within LLVM may be associated with address
1283 ranges allocated through mechanisms other than those provided by
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1284 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1285 allocated by mechanisms provided by LLVM.</li>
1286 </ul>
1287
1288<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1289<tt><a href="#i_load">load</a></tt> merely indicates the size and
1290alignment of the memory from which to load, as well as the
1291interpretation of the value. The first operand of a
1292<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1293and alignment of the store.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1294
1295<p>Consequently, type-based alias analysis, aka TBAA, aka
1296<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1297LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1298additional information which specialized optimization passes may use
1299to implement type-based alias analysis.</p>
1300
1301</div>
1302
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1303<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1304<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1305<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1306
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1307<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1308
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1309<p>The LLVM type system is one of the most important features of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1310 intermediate representation. Being typed enables a number of optimizations
1311 to be performed on the intermediate representation directly, without having
1312 to do extra analyses on the side before the transformation. A strong type
1313 system makes it easier to read the generated code and enables novel analyses
1314 and transformations that are not feasible to perform on normal three address
1315 code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1316
1317</div>
1318
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1319<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1320<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1321Classifications</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1322
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1323<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1324
1325<p>The types fall into a few useful classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1326
1327<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1328 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1329 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1330 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1331 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1332 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1333 </tr>
1334 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1335 <td><a href="#t_floating">floating point</a></td>
1336 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1337 </tr>
1338 <tr>
1339 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1340 <td><a href="#t_integer">integer</a>,
1341 <a href="#t_floating">floating point</a>,
1342 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1343 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1344 <a href="#t_struct">structure</a>,
1345 <a href="#t_array">array</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1346 <a href="#t_label">label</a>,
1347 <a href="#t_metadata">metadata</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1348 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1349 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1350 <tr>
1351 <td><a href="#t_primitive">primitive</a></td>
1352 <td><a href="#t_label">label</a>,
1353 <a href="#t_void">void</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1354 <a href="#t_floating">floating point</a>,
1355 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1356 </tr>
1357 <tr>
1358 <td><a href="#t_derived">derived</a></td>
1359 <td><a href="#t_integer">integer</a>,
1360 <a href="#t_array">array</a>,
1361 <a href="#t_function">function</a>,
1362 <a href="#t_pointer">pointer</a>,
1363 <a href="#t_struct">structure</a>,
1364 <a href="#t_pstruct">packed structure</a>,
1365 <a href="#t_vector">vector</a>,
1366 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1367 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1368 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1369 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1370</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1371
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1372<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1373 important. Values of these types are the only ones which can be produced by
1374 instructions, passed as arguments, or used as operands to instructions.</p>
1375
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1376</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1377
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1378<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1379<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1380
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1381<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1382
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1383<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1384 system.</p>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1385
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1386</div>
1387
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1388<!-- _______________________________________________________________________ -->
1389<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1390
1391<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1392
1393<table>
1394 <tbody>
1395 <tr><th>Type</th><th>Description</th></tr>
1396 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1397 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1398 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1399 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1400 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1401 </tbody>
1402</table>
1403
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1404</div>
1405
1406<!-- _______________________________________________________________________ -->
1407<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1408
1409<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1410
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1411<h5>Overview:</h5>
1412<p>The void type does not represent any value and has no size.</p>
1413
1414<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1415<pre>
1416 void
1417</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1418
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1419</div>
1420
1421<!-- _______________________________________________________________________ -->
1422<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1423
1424<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1425
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1426<h5>Overview:</h5>
1427<p>The label type represents code labels.</p>
1428
1429<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1430<pre>
1431 label
1432</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1433
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1434</div>
1435
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1436<!-- _______________________________________________________________________ -->
1437<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
1438
1439<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1440
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1441<h5>Overview:</h5>
1442<p>The metadata type represents embedded metadata. The only derived type that
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1443 may contain metadata is <tt>metadata*</tt> or a function type that returns or
1444 takes metadata typed parameters, but not pointer to metadata types.</p>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1445
1446<h5>Syntax:</h5>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1447<pre>
1448 metadata
1449</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1450
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1451</div>
1452
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1453
1454<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1455<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1456
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1457<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1458
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1459<p>The real power in LLVM comes from the derived types in the system. This is
1460 what allows a programmer to represent arrays, functions, pointers, and other
1461 useful types. Note that these derived types may be recursive: For example,
1462 it is possible to have a two dimensional array.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1463
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1464</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1465
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1466<!-- _______________________________________________________________________ -->
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1467<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1468
1469<div class="doc_text">
1470
1471<h5>Overview:</h5>
1472<p>The integer type is a very simple derived type that simply specifies an
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1473 arbitrary bit width for the integer type desired. Any bit width from 1 bit to
1474 2^23-1 (about 8 million) can be specified.</p>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1475
1476<h5>Syntax:</h5>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1477<pre>
1478 iN
1479</pre>
1480
1481<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]1482 value.</p>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1483
1484<h5>Examples:</h5>
1485<table class="layout">
Nick Lewycky86c48642009-05-24 02:46:06 +0000[diff] [blame]1486 <tr class="layout">
1487 <td class="left"><tt>i1</tt></td>
1488 <td class="left">a single-bit integer.</td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1489 </tr>
Nick Lewycky86c48642009-05-24 02:46:06 +0000[diff] [blame]1490 <tr class="layout">
1491 <td class="left"><tt>i32</tt></td>
1492 <td class="left">a 32-bit integer.</td>
1493 </tr>
1494 <tr class="layout">
1495 <td class="left"><tt>i1942652</tt></td>
1496 <td class="left">a really big integer of over 1 million bits.</td>
1497 </tr>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1498</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1499
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1500<p>Note that the code generator does not yet support large integer types to be
1501 used as function return types. The specific limit on how large a return type
1502 the code generator can currently handle is target-dependent; currently it's
1503 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]1504
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1505</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1506
1507<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1508<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1509
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1510<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1511
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1512<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1513<p>The array type is a very simple derived type that arranges elements
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1514 sequentially in memory. The array type requires a size (number of elements)
1515 and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1516
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1517<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1518<pre>
1519 [&lt;# elements&gt; x &lt;elementtype&gt;]
1520</pre>
1521
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1522<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1523 be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1524
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1525<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1526<table class="layout">
1527 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1528 <td class="left"><tt>[40 x i32]</tt></td>
1529 <td class="left">Array of 40 32-bit integer values.</td>
1530 </tr>
1531 <tr class="layout">
1532 <td class="left"><tt>[41 x i32]</tt></td>
1533 <td class="left">Array of 41 32-bit integer values.</td>
1534 </tr>
1535 <tr class="layout">
1536 <td class="left"><tt>[4 x i8]</tt></td>
1537 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1538 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1539</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1540<p>Here are some examples of multidimensional arrays:</p>
1541<table class="layout">
1542 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1543 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1544 <td class="left">3x4 array of 32-bit integer values.</td>
1545 </tr>
1546 <tr class="layout">
1547 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1548 <td class="left">12x10 array of single precision floating point values.</td>
1549 </tr>
1550 <tr class="layout">
1551 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1552 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1553 </tr>
1554</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1555
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1556<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1557 length array. Normally, accesses past the end of an array are undefined in
1558 LLVM (e.g. it is illegal to access the 5th element of a 3 element array). As
1559 a special case, however, zero length arrays are recognized to be variable
1560 length. This allows implementation of 'pascal style arrays' with the LLVM
1561 type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1562
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1563<p>Note that the code generator does not yet support large aggregate types to be
1564 used as function return types. The specific limit on how large an aggregate
1565 return type the code generator can currently handle is target-dependent, and
1566 also dependent on the aggregate element types.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1567
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1568</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1569
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1570<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1571<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1572
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1573<div class="doc_text">
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1574
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1575<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1576<p>The function type can be thought of as a function signature. It consists of
1577 a return type and a list of formal parameter types. The return type of a
1578 function type is a scalar type, a void type, or a struct type. If the return
1579 type is a struct type then all struct elements must be of first class types,
1580 and the struct must have at least one element.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1581
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1582<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1583<pre>
1584 &lt;returntype list&gt; (&lt;parameter list&gt;)
1585</pre>
1586
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1587<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]1588 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1589 which indicates that the function takes a variable number of arguments.
1590 Variable argument functions can access their arguments with
1591 the <a href="#int_varargs">variable argument handling intrinsic</a>
1592 functions. '<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1593 <a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1594
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1595<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1596<table class="layout">
1597 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1598 <td class="left"><tt>i32 (i32)</tt></td>
1599 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1600 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1601 </tr><tr class="layout">
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]1602 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1603 </tt></td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1604 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1605 an <tt>i16</tt> that should be sign extended and a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1606 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1607 <tt>float</tt>.
1608 </td>
1609 </tr><tr class="layout">
1610 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1611 <td class="left">A vararg function that takes at least one
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1612 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1613 which returns an integer. This is the signature for <tt>printf</tt> in
1614 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1615 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1616 </tr><tr class="layout">
1617 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukmanb0a57aa2008-11-27 06:41:20 +0000[diff] [blame]1618 <td class="left">A function taking an <tt>i32</tt>, returning two
1619 <tt>i32</tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1620 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1621 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1622</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1623
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1624</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1625
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1626<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1627<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1628
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1629<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1630
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1631<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1632<p>The structure type is used to represent a collection of data members together
1633 in memory. The packing of the field types is defined to match the ABI of the
1634 underlying processor. The elements of a structure may be any type that has a
1635 size.</p>
1636
1637<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1638 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1639 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1640
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1641<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1642<pre>
1643 { &lt;type list&gt; }
1644</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1645
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1646<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1647<table class="layout">
1648 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1649 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1650 <td class="left">A triple of three <tt>i32</tt> values</td>
1651 </tr><tr class="layout">
1652 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1653 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1654 second element is a <a href="#t_pointer">pointer</a> to a
1655 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1656 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1657 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1658</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1659
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1660<p>Note that the code generator does not yet support large aggregate types to be
1661 used as function return types. The specific limit on how large an aggregate
1662 return type the code generator can currently handle is target-dependent, and
1663 also dependent on the aggregate element types.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1664
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1665</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1666
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1667<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1668<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1669</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1670
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1671<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1672
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1673<h5>Overview:</h5>
1674<p>The packed structure type is used to represent a collection of data members
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1675 together in memory. There is no padding between fields. Further, the
1676 alignment of a packed structure is 1 byte. The elements of a packed
1677 structure may be any type that has a size.</p>
1678
1679<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1680 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1681 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1682
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1683<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1684<pre>
1685 &lt; { &lt;type list&gt; } &gt;
1686</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1687
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1688<h5>Examples:</h5>
1689<table class="layout">
1690 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1691 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1692 <td class="left">A triple of three <tt>i32</tt> values</td>
1693 </tr><tr class="layout">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1694 <td class="left">
1695<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1696 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1697 second element is a <a href="#t_pointer">pointer</a> to a
1698 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1699 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1700 </tr>
1701</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1702
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1703</div>
1704
1705<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1706<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1707
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1708<div class="doc_text">
1709
1710<h5>Overview:</h5>
1711<p>As in many languages, the pointer type represents a pointer or reference to
1712 another object, which must live in memory. Pointer types may have an optional
1713 address space attribute defining the target-specific numbered address space
1714 where the pointed-to object resides. The default address space is zero.</p>
1715
1716<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
1717 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1718
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1719<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1720<pre>
1721 &lt;type&gt; *
1722</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1723
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1724<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1725<table class="layout">
1726 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]1727 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1728 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1729 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1730 </tr>
1731 <tr class="layout">
1732 <td class="left"><tt>i32 (i32 *) *</tt></td>
1733 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1734 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1735 <tt>i32</tt>.</td>
1736 </tr>
1737 <tr class="layout">
1738 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1739 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1740 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1741 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1742</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1743
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1744</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1745
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1746<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1747<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1748
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1749<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1750
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1751<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1752<p>A vector type is a simple derived type that represents a vector of elements.
1753 Vector types are used when multiple primitive data are operated in parallel
1754 using a single instruction (SIMD). A vector type requires a size (number of
1755 elements) and an underlying primitive data type. Vectors must have a power
1756 of two length (1, 2, 4, 8, 16 ...). Vector types are considered
1757 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1758
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1759<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1760<pre>
1761 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1762</pre>
1763
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1764<p>The number of elements is a constant integer value; elementtype may be any
1765 integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1766
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1767<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1768<table class="layout">
1769 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1770 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1771 <td class="left">Vector of 4 32-bit integer values.</td>
1772 </tr>
1773 <tr class="layout">
1774 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1775 <td class="left">Vector of 8 32-bit floating-point values.</td>
1776 </tr>
1777 <tr class="layout">
1778 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1779 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1780 </tr>
1781</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1782
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1783<p>Note that the code generator does not yet support large vector types to be
1784 used as function return types. The specific limit on how large a vector
1785 return type codegen can currently handle is target-dependent; currently it's
1786 often a few times longer than a hardware vector register.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1787
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1788</div>
1789
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1790<!-- _______________________________________________________________________ -->
1791<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1792<div class="doc_text">
1793
1794<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1795<p>Opaque types are used to represent unknown types in the system. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1796 corresponds (for example) to the C notion of a forward declared structure
1797 type. In LLVM, opaque types can eventually be resolved to any type (not just
1798 a structure type).</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1799
1800<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1801<pre>
1802 opaque
1803</pre>
1804
1805<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1806<table class="layout">
1807 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1808 <td class="left"><tt>opaque</tt></td>
1809 <td class="left">An opaque type.</td>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1810 </tr>
1811</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1812
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1813</div>
1814
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1815<!-- ======================================================================= -->
1816<div class="doc_subsection">
1817 <a name="t_uprefs">Type Up-references</a>
1818</div>
1819
1820<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1821
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1822<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1823<p>An "up reference" allows you to refer to a lexically enclosing type without
1824 requiring it to have a name. For instance, a structure declaration may
1825 contain a pointer to any of the types it is lexically a member of. Example
1826 of up references (with their equivalent as named type declarations)
1827 include:</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1828
1829<pre>
Chris Lattner3060f5b2009-02-09 10:00:56 +0000[diff] [blame]1830 { \2 * } %x = type { %x* }
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1831 { \2 }* %y = type { %y }*
1832 \1* %z = type %z*
1833</pre>
1834
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1835<p>An up reference is needed by the asmprinter for printing out cyclic types
1836 when there is no declared name for a type in the cycle. Because the
1837 asmprinter does not want to print out an infinite type string, it needs a
1838 syntax to handle recursive types that have no names (all names are optional
1839 in llvm IR).</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1840
1841<h5>Syntax:</h5>
1842<pre>
1843 \&lt;level&gt;
1844</pre>
1845
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1846<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]1847
1848<h5>Examples:</h5>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1849<table class="layout">
1850 <tr class="layout">
1851 <td class="left"><tt>\1*</tt></td>
1852 <td class="left">Self-referential pointer.</td>
1853 </tr>
1854 <tr class="layout">
1855 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
1856 <td class="left">Recursive structure where the upref refers to the out-most
1857 structure.</td>
1858 </tr>
1859</table>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1860
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1861</div>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1862
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1863<!-- *********************************************************************** -->
1864<div class="doc_section"> <a name="constants">Constants</a> </div>
1865<!-- *********************************************************************** -->
1866
1867<div class="doc_text">
1868
1869<p>LLVM has several different basic types of constants. This section describes
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1870 them all and their syntax.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1871
1872</div>
1873
1874<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1875<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1876
1877<div class="doc_text">
1878
1879<dl>
1880 <dt><b>Boolean constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1881 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1882 constants of the <tt><a href="#t_primitive">i1</a></tt> type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1883
1884 <dt><b>Integer constants</b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1885 <dd>Standard integers (such as '4') are constants of
1886 the <a href="#t_integer">integer</a> type. Negative numbers may be used
1887 with integer types.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1888
1889 <dt><b>Floating point constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1890 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1891 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
1892 notation (see below). The assembler requires the exact decimal value of a
1893 floating-point constant. For example, the assembler accepts 1.25 but
1894 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1895 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1896
1897 <dt><b>Null pointer constants</b></dt>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1898 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1899 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1900</dl>
1901
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1902<p>The one non-intuitive notation for constants is the hexadecimal form of
1903 floating point constants. For example, the form '<tt>double
1904 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
1905 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
1906 constants are required (and the only time that they are generated by the
1907 disassembler) is when a floating point constant must be emitted but it cannot
1908 be represented as a decimal floating point number in a reasonable number of
1909 digits. For example, NaN's, infinities, and other special values are
1910 represented in their IEEE hexadecimal format so that assembly and disassembly
1911 do not cause any bits to change in the constants.</p>
1912
Dale Johannesenbd5e5a82009-02-11 22:14:51 +0000[diff] [blame]1913<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1914 represented using the 16-digit form shown above (which matches the IEEE754
1915 representation for double); float values must, however, be exactly
1916 representable as IEE754 single precision. Hexadecimal format is always used
1917 for long double, and there are three forms of long double. The 80-bit format
1918 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
1919 The 128-bit format used by PowerPC (two adjacent doubles) is represented
1920 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
1921 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
1922 currently supported target uses this format. Long doubles will only work if
1923 they match the long double format on your target. All hexadecimal formats
1924 are big-endian (sign bit at the left).</p>
1925
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1926</div>
1927
1928<!-- ======================================================================= -->
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]1929<div class="doc_subsection">
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]1930<a name="aggregateconstants"></a> <!-- old anchor -->
1931<a name="complexconstants">Complex Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1932</div>
1933
1934<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1935
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]1936<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1937 constants and smaller complex constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1938
1939<dl>
1940 <dt><b>Structure constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1941 <dd>Structure constants are represented with notation similar to structure
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1942 type definitions (a comma separated list of elements, surrounded by braces
1943 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1944 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
1945 Structure constants must have <a href="#t_struct">structure type</a>, and
1946 the number and types of elements must match those specified by the
1947 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1948
1949 <dt><b>Array constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1950 <dd>Array constants are represented with notation similar to array type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1951 definitions (a comma separated list of elements, surrounded by square
1952 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
1953 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
1954 the number and types of elements must match those specified by the
1955 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1956
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1957 <dt><b>Vector constants</b></dt>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1958 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1959 definitions (a comma separated list of elements, surrounded by
1960 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
1961 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
1962 have <a href="#t_vector">vector type</a>, and the number and types of
1963 elements must match those specified by the type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1964
1965 <dt><b>Zero initialization</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1966 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1967 value to zero of <em>any</em> type, including scalar and aggregate types.
1968 This is often used to avoid having to print large zero initializers
1969 (e.g. for large arrays) and is always exactly equivalent to using explicit
1970 zero initializers.</dd>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]1971
1972 <dt><b>Metadata node</b></dt>
Nick Lewycky1e8c7a62009-05-30 16:08:30 +0000[diff] [blame]1973 <dd>A metadata node is a structure-like constant with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1974 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
1975 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
1976 be interpreted as part of the instruction stream, metadata is a place to
1977 attach additional information such as debug info.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1978</dl>
1979
1980</div>
1981
1982<!-- ======================================================================= -->
1983<div class="doc_subsection">
1984 <a name="globalconstants">Global Variable and Function Addresses</a>
1985</div>
1986
1987<div class="doc_text">
1988
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1989<p>The addresses of <a href="#globalvars">global variables</a>
1990 and <a href="#functionstructure">functions</a> are always implicitly valid
1991 (link-time) constants. These constants are explicitly referenced when
1992 the <a href="#identifiers">identifier for the global</a> is used and always
1993 have <a href="#t_pointer">pointer</a> type. For example, the following is a
1994 legal LLVM file:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1995
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1996<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1997<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]1998@X = global i32 17
1999@Y = global i32 42
2000@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2001</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2002</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2003
2004</div>
2005
2006<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]2007<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2008<div class="doc_text">
2009
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2010<p>The string '<tt>undef</tt>' is recognized as a type-less constant that has no
2011 specific value. Undefined values may be of any type and be used anywhere a
2012 constant is permitted.</p>
2013
2014<p>Undefined values indicate to the compiler that the program is well defined no
2015 matter what value is used, giving the compiler more freedom to optimize.</p>
2016
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2017</div>
2018
2019<!-- ======================================================================= -->
2020<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
2021</div>
2022
2023<div class="doc_text">
2024
2025<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2026 to be used as constants. Constant expressions may be of
2027 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2028 operation that does not have side effects (e.g. load and call are not
2029 supported). The following is the syntax for constant expressions:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2030
2031<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2032 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2033 <dd>Truncate a constant to another type. The bit size of CST must be larger
2034 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2035
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2036 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2037 <dd>Zero extend a constant to another type. The bit size of CST must be
2038 smaller or equal to the bit size of TYPE. Both types must be
2039 integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2040
2041 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2042 <dd>Sign extend a constant to another type. The bit size of CST must be
2043 smaller or equal to the bit size of TYPE. Both types must be
2044 integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2045
2046 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2047 <dd>Truncate a floating point constant to another floating point type. The
2048 size of CST must be larger than the size of TYPE. Both types must be
2049 floating point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2050
2051 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2052 <dd>Floating point extend a constant to another type. The size of CST must be
2053 smaller or equal to the size of TYPE. Both types must be floating
2054 point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2055
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]2056 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2057 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2058 constant. TYPE must be a scalar or vector integer type. CST must be of
2059 scalar or vector floating point type. Both CST and TYPE must be scalars,
2060 or vectors of the same number of elements. If the value won't fit in the
2061 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2062
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2063 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2064 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2065 constant. TYPE must be a scalar or vector integer type. CST must be of
2066 scalar or vector floating point type. Both CST and TYPE must be scalars,
2067 or vectors of the same number of elements. If the value won't fit in the
2068 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2069
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2070 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2071 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2072 constant. TYPE must be a scalar or vector floating point type. CST must be
2073 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2074 vectors of the same number of elements. If the value won't fit in the
2075 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2076
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2077 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2078 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2079 constant. TYPE must be a scalar or vector floating point type. CST must be
2080 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2081 vectors of the same number of elements. If the value won't fit in the
2082 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2083
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2084 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
2085 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2086 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2087 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2088 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2089
2090 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2091 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2092 type. CST must be of integer type. The CST value is zero extended,
2093 truncated, or unchanged to make it fit in a pointer size. This one is
2094 <i>really</i> dangerous!</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2095
2096 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner03bbad62009-02-28 18:27:03 +0000[diff] [blame]2097 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2098 are the same as those for the <a href="#i_bitcast">bitcast
2099 instruction</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2100
2101 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]2102 <dt><b><tt>getelementptr inbounds ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2103 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2104 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2105 instruction, the index list may have zero or more indexes, which are
2106 required to make sense for the type of "CSTPTR".</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2107
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2108 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2109 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2110
2111 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
2112 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2113
2114 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
2115 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2116
2117 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2118 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2119 constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2120
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]2121 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2122 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2123 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2124
2125 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2126 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2127 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2128
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2129 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2130 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2131 be any of the <a href="#binaryops">binary</a>
2132 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2133 on operands are the same as those for the corresponding instruction
2134 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2135</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2136
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2137</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]2138
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2139<!-- ======================================================================= -->
2140<div class="doc_subsection"><a name="metadata">Embedded Metadata</a>
2141</div>
2142
2143<div class="doc_text">
2144
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2145<p>Embedded metadata provides a way to attach arbitrary data to the instruction
2146 stream without affecting the behaviour of the program. There are two
2147 metadata primitives, strings and nodes. All metadata has the
2148 <tt>metadata</tt> type and is identified in syntax by a preceding exclamation
2149 point ('<tt>!</tt>').</p>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2150
2151<p>A metadata string is a string surrounded by double quotes. It can contain
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2152 any character by escaping non-printable characters with "\xx" where "xx" is
2153 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2154
2155<p>Metadata nodes are represented with notation similar to structure constants
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2156 (a comma separated list of elements, surrounded by braces and preceeded by an
2157 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2158 10}</tt>".</p>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2159
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2160<p>A metadata node will attempt to track changes to the values it holds. In the
2161 event that a value is deleted, it will be replaced with a typeless
2162 "<tt>null</tt>", such as "<tt>metadata !{null, i32 10}</tt>".</p>
Nick Lewyckycb337992009-05-10 20:57:05 +0000[diff] [blame]2163
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2164<p>Optimizations may rely on metadata to provide additional information about
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2165 the program that isn't available in the instructions, or that isn't easily
2166 computable. Similarly, the code generator may expect a certain metadata
2167 format to be used to express debugging information.</p>
2168
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2169</div>
2170
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2171<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2172<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
2173<!-- *********************************************************************** -->
2174
2175<!-- ======================================================================= -->
2176<div class="doc_subsection">
2177<a name="inlineasm">Inline Assembler Expressions</a>
2178</div>
2179
2180<div class="doc_text">
2181
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2182<p>LLVM supports inline assembler expressions (as opposed
2183 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2184 a special value. This value represents the inline assembler as a string
2185 (containing the instructions to emit), a list of operand constraints (stored
2186 as a string), and a flag that indicates whether or not the inline asm
2187 expression has side effects. An example inline assembler expression is:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2188
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2189<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2190<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2191i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2192</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2193</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2194
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2195<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2196 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2197 have:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2198
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2199<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2200<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2201%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]2202</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2203</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2204
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2205<p>Inline asms with side effects not visible in the constraint list must be
2206 marked as having side effects. This is done through the use of the
2207 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2208
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2209<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2210<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2211call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2212</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2213</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2214
2215<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2216 documented here. Constraints on what can be done (e.g. duplication, moving,
2217 etc need to be documented). This is probably best done by reference to
2218 another document that covers inline asm from a holistic perspective.</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2219
2220</div>
2221
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2222
2223<!-- *********************************************************************** -->
2224<div class="doc_section">
2225 <a name="intrinsic_globals">Intrinsic Global Variables</a>
2226</div>
2227<!-- *********************************************************************** -->
2228
2229<p>LLVM has a number of "magic" global variables that contain data that affect
2230code generation or other IR semantics. These are documented here. All globals
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2231of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2232section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2233by LLVM.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2234
2235<!-- ======================================================================= -->
2236<div class="doc_subsection">
2237<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
2238</div>
2239
2240<div class="doc_text">
2241
2242<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2243href="#linkage_appending">appending linkage</a>. This array contains a list of
2244pointers to global variables and functions which may optionally have a pointer
2245cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2246
2247<pre>
2248 @X = global i8 4
2249 @Y = global i32 123
2250
2251 @llvm.used = appending global [2 x i8*] [
2252 i8* @X,
2253 i8* bitcast (i32* @Y to i8*)
2254 ], section "llvm.metadata"
2255</pre>
2256
2257<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2258compiler, assembler, and linker are required to treat the symbol as if there is
2259a reference to the global that it cannot see. For example, if a variable has
2260internal linkage and no references other than that from the <tt>@llvm.used</tt>
2261list, it cannot be deleted. This is commonly used to represent references from
2262inline asms and other things the compiler cannot "see", and corresponds to
2263"attribute((used))" in GNU C.</p>
2264
2265<p>On some targets, the code generator must emit a directive to the assembler or
2266object file to prevent the assembler and linker from molesting the symbol.</p>
2267
2268</div>
2269
2270<!-- ======================================================================= -->
2271<div class="doc_subsection">
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2272<a name="intg_compiler_used">The '<tt>llvm.compiler.used</tt>' Global Variable</a>
2273</div>
2274
2275<div class="doc_text">
2276
2277<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2278<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2279touching the symbol. On targets that support it, this allows an intelligent
2280linker to optimize references to the symbol without being impeded as it would be
2281by <tt>@llvm.used</tt>.</p>
2282
2283<p>This is a rare construct that should only be used in rare circumstances, and
2284should not be exposed to source languages.</p>
2285
2286</div>
2287
2288<!-- ======================================================================= -->
2289<div class="doc_subsection">
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2290<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
2291</div>
2292
2293<div class="doc_text">
2294
2295<p>TODO: Describe this.</p>
2296
2297</div>
2298
2299<!-- ======================================================================= -->
2300<div class="doc_subsection">
2301<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
2302</div>
2303
2304<div class="doc_text">
2305
2306<p>TODO: Describe this.</p>
2307
2308</div>
2309
2310
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2311<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2312<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
2313<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2314
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2315<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2316
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2317<p>The LLVM instruction set consists of several different classifications of
2318 instructions: <a href="#terminators">terminator
2319 instructions</a>, <a href="#binaryops">binary instructions</a>,
2320 <a href="#bitwiseops">bitwise binary instructions</a>,
2321 <a href="#memoryops">memory instructions</a>, and
2322 <a href="#otherops">other instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2323
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2324</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2325
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2326<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2327<div class="doc_subsection"> <a name="terminators">Terminator
2328Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2329
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2330<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2331
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2332<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2333 in a program ends with a "Terminator" instruction, which indicates which
2334 block should be executed after the current block is finished. These
2335 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2336 control flow, not values (the one exception being the
2337 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2338
2339<p>There are six different terminator instructions: the
2340 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2341 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2342 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
2343 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2344 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2345 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2346
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2347</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2348
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2349<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2350<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
2351Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2352
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2353<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2354
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2355<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2356<pre>
2357 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]2358 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2359</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2360
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2361<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2362<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2363 a value) from a function back to the caller.</p>
2364
2365<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2366 value and then causes control flow, and one that just causes control flow to
2367 occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2368
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2369<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2370<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2371 return value. The type of the return value must be a
2372 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2373
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2374<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2375 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2376 value or a return value with a type that does not match its type, or if it
2377 has a void return type and contains a '<tt>ret</tt>' instruction with a
2378 return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2379
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2380<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2381<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2382 the calling function's context. If the caller is a
2383 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2384 instruction after the call. If the caller was an
2385 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2386 the beginning of the "normal" destination block. If the instruction returns
2387 a value, that value shall set the call or invoke instruction's return
2388 value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2389
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2390<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2391<pre>
2392 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2393 ret void <i>; Return from a void function</i>
Bill Wendling0a4bbbf2009-02-28 22:12:54 +0000[diff] [blame]2394 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]2395</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2396
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]2397<p>Note that the code generator does not yet fully support large
2398 return values. The specific sizes that are currently supported are
2399 dependent on the target. For integers, on 32-bit targets the limit
2400 is often 64 bits, and on 64-bit targets the limit is often 128 bits.
2401 For aggregate types, the current limits are dependent on the element
2402 types; for example targets are often limited to 2 total integer
2403 elements and 2 total floating-point elements.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2404
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2405</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2406<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2407<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2408
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2409<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2410
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2411<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2412<pre>
2413 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]2414</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2415
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2416<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2417<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
2418 different basic block in the current function. There are two forms of this
2419 instruction, corresponding to a conditional branch and an unconditional
2420 branch.</p>
2421
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2422<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2423<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
2424 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
2425 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
2426 target.</p>
2427
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2428<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2429<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2430 argument is evaluated. If the value is <tt>true</tt>, control flows to the
2431 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2432 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
2433
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2434<h5>Example:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2435<pre>
2436Test:
2437 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
2438 br i1 %cond, label %IfEqual, label %IfUnequal
2439IfEqual:
2440 <a href="#i_ret">ret</a> i32 1
2441IfUnequal:
2442 <a href="#i_ret">ret</a> i32 0
2443</pre>
2444
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2445</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2446
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2447<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2448<div class="doc_subsubsection">
2449 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2450</div>
2451
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2452<div class="doc_text">
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2453
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2454<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2455<pre>
2456 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2457</pre>
2458
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2459<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2460<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]2461 several different places. It is a generalization of the '<tt>br</tt>'
2462 instruction, allowing a branch to occur to one of many possible
2463 destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2464
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2465<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2466<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2467 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
2468 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
2469 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2470
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2471<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2472<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2473 destinations. When the '<tt>switch</tt>' instruction is executed, this table
2474 is searched for the given value. If the value is found, control flow is
2475 transfered to the corresponding destination; otherwise, control flow is
2476 transfered to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2477
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2478<h5>Implementation:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2479<p>Depending on properties of the target machine and the particular
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2480 <tt>switch</tt> instruction, this instruction may be code generated in
2481 different ways. For example, it could be generated as a series of chained
2482 conditional branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2483
2484<h5>Example:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2485<pre>
2486 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2487 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2488 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2489
2490 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2491 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2492
2493 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2494 switch i32 %val, label %otherwise [ i32 0, label %onzero
2495 i32 1, label %onone
2496 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2497</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2498
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2499</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2500
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2501<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2502<div class="doc_subsubsection">
2503 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2504</div>
2505
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2506<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2507
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2508<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2509<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2510 &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]2511 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2512</pre>
2513
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2514<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2515<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2516 function, with the possibility of control flow transfer to either the
2517 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
2518 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
2519 control flow will return to the "normal" label. If the callee (or any
2520 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
2521 instruction, control is interrupted and continued at the dynamically nearest
2522 "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2523
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2524<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2525<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2526
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2527<ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2528 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
2529 convention</a> the call should use. If none is specified, the call
2530 defaults to using C calling conventions.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2531
2532 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2533 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
2534 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2535
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2536 <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]2537 function value being invoked. In most cases, this is a direct function
2538 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
2539 off an arbitrary pointer to function value.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2540
2541 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2542 function to be invoked. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2543
2544 <li>'<tt>function args</tt>': argument list whose types match the function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2545 signature argument types. If the function signature indicates the
2546 function accepts a variable number of arguments, the extra arguments can
2547 be specified.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2548
2549 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2550 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2551
2552 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2553 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2554
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2555 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2556 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2557 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2558</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2559
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2560<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2561<p>This instruction is designed to operate as a standard
2562 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
2563 primary difference is that it establishes an association with a label, which
2564 is used by the runtime library to unwind the stack.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2565
2566<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2567 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2568 exception. Additionally, this is important for implementation of
2569 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2570
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2571<p>For the purposes of the SSA form, the definition of the value returned by the
2572 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
2573 block to the "normal" label. If the callee unwinds then no return value is
2574 available.</p>
Dan Gohmanf96a4992009-05-22 21:47:08 +0000[diff] [blame]2575
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2576<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2577<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2578 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2579 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2580 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2581 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2582</pre>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2583
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2584</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2585
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2586<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2587
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2588<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2589Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2590
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2591<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2592
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2593<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2594<pre>
2595 unwind
2596</pre>
2597
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2598<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2599<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2600 at the first callee in the dynamic call stack which used
2601 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
2602 This is primarily used to implement exception handling.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2603
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2604<h5>Semantics:</h5>
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]2605<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2606 immediately halt. The dynamic call stack is then searched for the
2607 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
2608 Once found, execution continues at the "exceptional" destination block
2609 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
2610 instruction in the dynamic call chain, undefined behavior results.</p>
2611
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2612</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2613
2614<!-- _______________________________________________________________________ -->
2615
2616<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2617Instruction</a> </div>
2618
2619<div class="doc_text">
2620
2621<h5>Syntax:</h5>
2622<pre>
2623 unreachable
2624</pre>
2625
2626<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2627<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2628 instruction is used to inform the optimizer that a particular portion of the
2629 code is not reachable. This can be used to indicate that the code after a
2630 no-return function cannot be reached, and other facts.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2631
2632<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2633<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2634
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2635</div>
2636
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2637<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2638<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2639
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2640<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2641
2642<p>Binary operators are used to do most of the computation in a program. They
2643 require two operands of the same type, execute an operation on them, and
2644 produce a single value. The operands might represent multiple data, as is
2645 the case with the <a href="#t_vector">vector</a> data type. The result value
2646 has the same type as its operands.</p>
2647
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2648<p>There are several different binary operators:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2649
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2650</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2651
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2652<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2653<div class="doc_subsubsection">
2654 <a name="i_add">'<tt>add</tt>' Instruction</a>
2655</div>
2656
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2657<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2658
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2659<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2660<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2661 &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]2662 &lt;result&gt; = nuw add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2663 &lt;result&gt; = nsw add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2664 &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]2665</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2666
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2667<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2668<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2669
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2670<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2671<p>The two arguments to the '<tt>add</tt>' instruction must
2672 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2673 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2674
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2675<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2676<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2677
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2678<p>If the sum has unsigned overflow, the result returned is the mathematical
2679 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]2680
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2681<p>Because LLVM integers use a two's complement representation, this instruction
2682 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2683
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]2684<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2685 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2686 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
2687 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2688
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2689<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2690<pre>
2691 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2692</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2693
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2694</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2695
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2696<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2697<div class="doc_subsubsection">
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2698 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
2699</div>
2700
2701<div class="doc_text">
2702
2703<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2704<pre>
2705 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2706</pre>
2707
2708<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2709<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
2710
2711<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2712<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2713 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2714 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2715
2716<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2717<p>The value produced is the floating point sum of the two operands.</p>
2718
2719<h5>Example:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2720<pre>
2721 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
2722</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2723
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2724</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2725
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2726<!-- _______________________________________________________________________ -->
2727<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2728 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2729</div>
2730
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2731<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2732
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2733<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2734<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]2735 &lt;result&gt; = sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2736 &lt;result&gt; = nuw sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2737 &lt;result&gt; = nsw sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2738 &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]2739</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2740
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2741<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2742<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2743 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2744
2745<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2746 '<tt>neg</tt>' instruction present in most other intermediate
2747 representations.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2748
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2749<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2750<p>The two arguments to the '<tt>sub</tt>' instruction must
2751 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2752 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2753
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2754<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2755<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2756
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2757<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2758 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
2759 result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2760
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2761<p>Because LLVM integers use a two's complement representation, this instruction
2762 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2763
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]2764<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2765 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2766 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
2767 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2768
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2769<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2770<pre>
2771 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2772 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2773</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2774
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2775</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2776
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2777<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2778<div class="doc_subsubsection">
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2779 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
2780</div>
2781
2782<div class="doc_text">
2783
2784<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2785<pre>
2786 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2787</pre>
2788
2789<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2790<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2791 operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2792
2793<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2794 '<tt>fneg</tt>' instruction present in most other intermediate
2795 representations.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2796
2797<h5>Arguments:</h5>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]2798<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2799 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2800 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2801
2802<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2803<p>The value produced is the floating point difference of the two operands.</p>
2804
2805<h5>Example:</h5>
2806<pre>
2807 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
2808 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
2809</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2810
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2811</div>
2812
2813<!-- _______________________________________________________________________ -->
2814<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2815 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2816</div>
2817
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2818<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2819
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2820<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2821<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]2822 &lt;result&gt; = mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2823 &lt;result&gt; = nuw mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2824 &lt;result&gt; = nsw mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2825 &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]2826</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2827
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2828<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2829<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2830
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2831<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2832<p>The two arguments to the '<tt>mul</tt>' instruction must
2833 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2834 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2835
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2836<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2837<p>The value produced is the integer product of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2838
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2839<p>If the result of the multiplication has unsigned overflow, the result
2840 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
2841 width of the result.</p>
2842
2843<p>Because LLVM integers use a two's complement representation, and the result
2844 is the same width as the operands, this instruction returns the correct
2845 result for both signed and unsigned integers. If a full product
2846 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
2847 be sign-extended or zero-extended as appropriate to the width of the full
2848 product.</p>
2849
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]2850<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2851 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2852 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
2853 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2854
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2855<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2856<pre>
2857 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2858</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2859
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2860</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2861
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2862<!-- _______________________________________________________________________ -->
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2863<div class="doc_subsubsection">
2864 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
2865</div>
2866
2867<div class="doc_text">
2868
2869<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2870<pre>
2871 &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]2872</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2873
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2874<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2875<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2876
2877<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2878<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2879 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2880 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2881
2882<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2883<p>The value produced is the floating point product of the two operands.</p>
2884
2885<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2886<pre>
2887 &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]2888</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2889
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2890</div>
2891
2892<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2893<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2894</a></div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2895
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2896<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2897
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2898<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2899<pre>
2900 &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]2901</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2902
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2903<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2904<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2905
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2906<h5>Arguments:</h5>
2907<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2908 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2909 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2910
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2911<h5>Semantics:</h5>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2912<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2913
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2914<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2915 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2916
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2917<p>Division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2918
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2919<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2920<pre>
2921 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2922</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2923
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2924</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2925
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2926<!-- _______________________________________________________________________ -->
2927<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2928</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2929
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2930<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2931
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2932<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2933<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2934 &lt;result&gt; = sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2935 &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]2936</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2937
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2938<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2939<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2940
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2941<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2942<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2943 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2944 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2945
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2946<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2947<p>The value produced is the signed integer quotient of the two operands rounded
2948 towards zero.</p>
2949
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2950<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2951 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2952
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2953<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2954 undefined behavior; this is a rare case, but can occur, for example, by doing
2955 a 32-bit division of -2147483648 by -1.</p>
2956
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame]2957<p>If the <tt>exact</tt> keyword is present, the result value of the
2958 <tt>sdiv</tt> is undefined if the result would be rounded or if overflow
2959 would occur.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2960
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2961<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2962<pre>
2963 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2964</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2965
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2966</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2967
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2968<!-- _______________________________________________________________________ -->
2969<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2970Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2971
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2972<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2973
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2974<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2975<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2976 &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]2977</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2978
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2979<h5>Overview:</h5>
2980<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2981
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2982<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2983<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2984 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2985 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2986
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2987<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2988<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2989
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2990<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2991<pre>
2992 &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]2993</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2994
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2995</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2996
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2997<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2998<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2999</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3000
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3001<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3002
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3003<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3004<pre>
3005 &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]3006</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3007
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3008<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3009<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3010 division of its two arguments.</p>
3011
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3012<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3013<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3014 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3015 values. Both arguments must have identical types.</p>
3016
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3017<h5>Semantics:</h5>
3018<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3019 This instruction always performs an unsigned division to get the
3020 remainder.</p>
3021
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3022<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3023 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3024
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3025<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3026
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3027<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3028<pre>
3029 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3030</pre>
3031
3032</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3033
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3034<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3035<div class="doc_subsubsection">
3036 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
3037</div>
3038
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3039<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3040
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3041<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3042<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3043 &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]3044</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3045
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3046<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3047<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3048 division of its two operands. This instruction can also take
3049 <a href="#t_vector">vector</a> versions of the values in which case the
3050 elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]3051
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3052<h5>Arguments:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3053<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3054 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3055 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3056
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3057<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3058<p>This instruction returns the <i>remainder</i> of a division (where the result
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3059 has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
3060 operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
3061 a value. For more information about the difference,
3062 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3063 Math Forum</a>. For a table of how this is implemented in various languages,
3064 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3065 Wikipedia: modulo operation</a>.</p>
3066
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3067<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3068 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3069
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3070<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3071 Overflow also leads to undefined behavior; this is a rare case, but can
3072 occur, for example, by taking the remainder of a 32-bit division of
3073 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3074 lets srem be implemented using instructions that return both the result of
3075 the division and the remainder.)</p>
3076
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3077<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3078<pre>
3079 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3080</pre>
3081
3082</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3083
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3084<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3085<div class="doc_subsubsection">
3086 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
3087
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3088<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3089
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3090<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3091<pre>
3092 &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]3093</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3094
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3095<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3096<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3097 its two operands.</p>
3098
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3099<h5>Arguments:</h5>
3100<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3101 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3102 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3103
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3104<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3105<p>This instruction returns the <i>remainder</i> of a division. The remainder
3106 has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3107
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3108<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3109<pre>
3110 &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]3111</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3112
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3113</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]3114
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3115<!-- ======================================================================= -->
3116<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
3117Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3118
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3119<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3120
3121<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3122 program. They are generally very efficient instructions and can commonly be
3123 strength reduced from other instructions. They require two operands of the
3124 same type, execute an operation on them, and produce a single value. The
3125 resulting value is the same type as its operands.</p>
3126
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3127</div>
3128
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3129<!-- _______________________________________________________________________ -->
3130<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
3131Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3132
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3133<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3134
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3135<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3136<pre>
3137 &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]3138</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3139
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3140<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3141<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3142 a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3143
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3144<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3145<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3146 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3147 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3148
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3149<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3150<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3151 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3152 is (statically or dynamically) negative or equal to or larger than the number
3153 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3154 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3155 shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3156
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3157<h5>Example:</h5>
3158<pre>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3159 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3160 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3161 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3162 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3163 &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]3164</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3165
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3166</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3167
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3168<!-- _______________________________________________________________________ -->
3169<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
3170Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3171
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3172<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3173
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3174<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3175<pre>
3176 &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]3177</pre>
3178
3179<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3180<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3181 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3182
3183<h5>Arguments:</h5>
3184<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3185 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3186 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3187
3188<h5>Semantics:</h5>
3189<p>This instruction always performs a logical shift right operation. The most
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3190 significant bits of the result will be filled with zero bits after the shift.
3191 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3192 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3193 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3194 shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3195
3196<h5>Example:</h5>
3197<pre>
3198 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3199 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3200 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3201 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3202 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3203 &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]3204</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3205
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3206</div>
3207
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3208<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3209<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
3210Instruction</a> </div>
3211<div class="doc_text">
3212
3213<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3214<pre>
3215 &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]3216</pre>
3217
3218<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3219<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3220 operand shifted to the right a specified number of bits with sign
3221 extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3222
3223<h5>Arguments:</h5>
3224<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3225 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3226 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3227
3228<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3229<p>This instruction always performs an arithmetic shift right operation, The
3230 most significant bits of the result will be filled with the sign bit
3231 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3232 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3233 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3234 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3235
3236<h5>Example:</h5>
3237<pre>
3238 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3239 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3240 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3241 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3242 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3243 &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]3244</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3245
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3246</div>
3247
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3248<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3249<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
3250Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3251
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3252<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3253
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3254<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3255<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3256 &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]3257</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3258
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3259<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3260<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3261 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3262
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3263<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3264<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3265 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3266 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3267
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3268<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3269<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3270
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3271<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3272 <tbody>
3273 <tr>
3274 <td>In0</td>
3275 <td>In1</td>
3276 <td>Out</td>
3277 </tr>
3278 <tr>
3279 <td>0</td>
3280 <td>0</td>
3281 <td>0</td>
3282 </tr>
3283 <tr>
3284 <td>0</td>
3285 <td>1</td>
3286 <td>0</td>
3287 </tr>
3288 <tr>
3289 <td>1</td>
3290 <td>0</td>
3291 <td>0</td>
3292 </tr>
3293 <tr>
3294 <td>1</td>
3295 <td>1</td>
3296 <td>1</td>
3297 </tr>
3298 </tbody>
3299</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3300
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3301<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3302<pre>
3303 &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]3304 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3305 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3306</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3307</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3308<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3309<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3310
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3311<div class="doc_text">
3312
3313<h5>Syntax:</h5>
3314<pre>
3315 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3316</pre>
3317
3318<h5>Overview:</h5>
3319<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
3320 two operands.</p>
3321
3322<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3323<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3324 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3325 values. Both arguments must have identical types.</p>
3326
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3327<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3328<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3329
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3330<table border="1" cellspacing="0" cellpadding="4">
3331 <tbody>
3332 <tr>
3333 <td>In0</td>
3334 <td>In1</td>
3335 <td>Out</td>
3336 </tr>
3337 <tr>
3338 <td>0</td>
3339 <td>0</td>
3340 <td>0</td>
3341 </tr>
3342 <tr>
3343 <td>0</td>
3344 <td>1</td>
3345 <td>1</td>
3346 </tr>
3347 <tr>
3348 <td>1</td>
3349 <td>0</td>
3350 <td>1</td>
3351 </tr>
3352 <tr>
3353 <td>1</td>
3354 <td>1</td>
3355 <td>1</td>
3356 </tr>
3357 </tbody>
3358</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3359
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3360<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3361<pre>
3362 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3363 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
3364 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3365</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3366
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3367</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3368
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3369<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3370<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
3371Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3372
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3373<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3374
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3375<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3376<pre>
3377 &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]3378</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3379
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3380<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3381<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
3382 its two operands. The <tt>xor</tt> is used to implement the "one's
3383 complement" operation, which is the "~" operator in C.</p>
3384
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3385<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3386<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3387 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3388 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3389
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3390<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3391<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3392
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3393<table border="1" cellspacing="0" cellpadding="4">
3394 <tbody>
3395 <tr>
3396 <td>In0</td>
3397 <td>In1</td>
3398 <td>Out</td>
3399 </tr>
3400 <tr>
3401 <td>0</td>
3402 <td>0</td>
3403 <td>0</td>
3404 </tr>
3405 <tr>
3406 <td>0</td>
3407 <td>1</td>
3408 <td>1</td>
3409 </tr>
3410 <tr>
3411 <td>1</td>
3412 <td>0</td>
3413 <td>1</td>
3414 </tr>
3415 <tr>
3416 <td>1</td>
3417 <td>1</td>
3418 <td>0</td>
3419 </tr>
3420 </tbody>
3421</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3422
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3423<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3424<pre>
3425 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3426 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
3427 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
3428 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3429</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3430
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3431</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3432
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3433<!-- ======================================================================= -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3434<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3435 <a name="vectorops">Vector Operations</a>
3436</div>
3437
3438<div class="doc_text">
3439
3440<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3441 target-independent manner. These instructions cover the element-access and
3442 vector-specific operations needed to process vectors effectively. While LLVM
3443 does directly support these vector operations, many sophisticated algorithms
3444 will want to use target-specific intrinsics to take full advantage of a
3445 specific target.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3446
3447</div>
3448
3449<!-- _______________________________________________________________________ -->
3450<div class="doc_subsubsection">
3451 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
3452</div>
3453
3454<div class="doc_text">
3455
3456<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3457<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3458 &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]3459</pre>
3460
3461<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3462<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
3463 from a vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3464
3465
3466<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3467<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
3468 of <a href="#t_vector">vector</a> type. The second operand is an index
3469 indicating the position from which to extract the element. The index may be
3470 a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3471
3472<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3473<p>The result is a scalar of the same type as the element type of
3474 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
3475 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3476 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3477
3478<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3479<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3480 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3481</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3482
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3483</div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3484
3485<!-- _______________________________________________________________________ -->
3486<div class="doc_subsubsection">
3487 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
3488</div>
3489
3490<div class="doc_text">
3491
3492<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3493<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]3494 &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]3495</pre>
3496
3497<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3498<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
3499 vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3500
3501<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3502<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
3503 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
3504 whose type must equal the element type of the first operand. The third
3505 operand is an index indicating the position at which to insert the value.
3506 The index may be a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3507
3508<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3509<p>The result is a vector of the same type as <tt>val</tt>. Its element values
3510 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
3511 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3512 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3513
3514<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3515<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3516 %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]3517</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3518
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3519</div>
3520
3521<!-- _______________________________________________________________________ -->
3522<div class="doc_subsubsection">
3523 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3524</div>
3525
3526<div class="doc_text">
3527
3528<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3529<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3530 &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]3531</pre>
3532
3533<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3534<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
3535 from two input vectors, returning a vector with the same element type as the
3536 input and length that is the same as the shuffle mask.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3537
3538<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3539<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
3540 with types that match each other. The third argument is a shuffle mask whose
3541 element type is always 'i32'. The result of the instruction is a vector
3542 whose length is the same as the shuffle mask and whose element type is the
3543 same as the element type of the first two operands.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3544
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3545<p>The shuffle mask operand is required to be a constant vector with either
3546 constant integer or undef values.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3547
3548<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3549<p>The elements of the two input vectors are numbered from left to right across
3550 both of the vectors. The shuffle mask operand specifies, for each element of
3551 the result vector, which element of the two input vectors the result element
3552 gets. The element selector may be undef (meaning "don't care") and the
3553 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3554
3555<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3556<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3557 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3558 &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]3559 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
3560 &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]3561 %result = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
3562 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
3563 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
3564 &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]3565</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3566
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3567</div>
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]3568
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3569<!-- ======================================================================= -->
3570<div class="doc_subsection">
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3571 <a name="aggregateops">Aggregate Operations</a>
3572</div>
3573
3574<div class="doc_text">
3575
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3576<p>LLVM supports several instructions for working with aggregate values.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3577
3578</div>
3579
3580<!-- _______________________________________________________________________ -->
3581<div class="doc_subsubsection">
3582 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3583</div>
3584
3585<div class="doc_text">
3586
3587<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3588<pre>
3589 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3590</pre>
3591
3592<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3593<p>The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3594 or array element from an aggregate value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3595
3596<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3597<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
3598 of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type. The
3599 operands are constant indices to specify which value to extract in a similar
3600 manner as indices in a
3601 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3602
3603<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3604<p>The result is the value at the position in the aggregate specified by the
3605 index operands.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3606
3607<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3608<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3609 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3610</pre>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3611
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3612</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3613
3614<!-- _______________________________________________________________________ -->
3615<div class="doc_subsubsection">
3616 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3617</div>
3618
3619<div class="doc_text">
3620
3621<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3622<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3623 &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]3624</pre>
3625
3626<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3627<p>The '<tt>insertvalue</tt>' instruction inserts a value into a struct field or
3628 array element in an aggregate.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3629
3630
3631<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3632<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
3633 of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type. The
3634 second operand is a first-class value to insert. The following operands are
3635 constant indices indicating the position at which to insert the value in a
3636 similar manner as indices in a
3637 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction. The
3638 value to insert must have the same type as the value identified by the
3639 indices.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3640
3641<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3642<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
3643 that of <tt>val</tt> except that the value at the position specified by the
3644 indices is that of <tt>elt</tt>.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3645
3646<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3647<pre>
Dan Gohman52bb2db2008-06-23 15:26:37 +0000[diff] [blame]3648 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3649</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3650
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3651</div>
3652
3653
3654<!-- ======================================================================= -->
3655<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3656 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3657</div>
3658
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3659<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3660
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3661<p>A key design point of an SSA-based representation is how it represents
3662 memory. In LLVM, no memory locations are in SSA form, which makes things
3663 very simple. This section describes how to read, write, allocate, and free
3664 memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3665
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3666</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3667
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3668<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3669<div class="doc_subsubsection">
3670 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3671</div>
3672
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3673<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3674
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3675<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3676<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3677 &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]3678</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3679
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3680<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3681<p>The '<tt>malloc</tt>' instruction allocates memory from the system heap and
3682 returns a pointer to it. The object is always allocated in the generic
3683 address space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3684
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3685<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3686<p>The '<tt>malloc</tt>' instruction allocates
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3687 <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory from the operating
3688 system and returns a pointer of the appropriate type to the program. If
3689 "NumElements" is specified, it is the number of elements allocated, otherwise
3690 "NumElements" is defaulted to be one. If a constant alignment is specified,
3691 the value result of the allocation is guaranteed to be aligned to at least
3692 that boundary. If not specified, or if zero, the target can choose to align
3693 the allocation on any convenient boundary compatible with the type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3694
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3695<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3696
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3697<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3698<p>Memory is allocated using the system "<tt>malloc</tt>" function, and a
3699 pointer is returned. The result of a zero byte allocation is undefined. The
3700 result is null if there is insufficient memory available.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3701
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3702<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3703<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3704 %array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3705
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3706 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3707 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3708 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3709 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3710 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3711</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]3712
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3713<p>Note that the code generator does not yet respect the alignment value.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]3714
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3715</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3716
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3717<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3718<div class="doc_subsubsection">
3719 <a name="i_free">'<tt>free</tt>' Instruction</a>
3720</div>
3721
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3722<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3723
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3724<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3725<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3726 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3727</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3728
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3729<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3730<p>The '<tt>free</tt>' instruction returns memory back to the unused memory heap
3731 to be reallocated in the future.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3732
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3733<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3734<p>'<tt>value</tt>' shall be a pointer value that points to a value that was
3735 allocated with the '<tt><a href="#i_malloc">malloc</a></tt>' instruction.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3736
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3737<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3738<p>Access to the memory pointed to by the pointer is no longer defined after
3739 this instruction executes. If the pointer is null, the operation is a
3740 noop.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3741
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3742<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3743<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3744 %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]3745 free [4 x i8]* %array
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3746</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3747
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3748</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3749
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3750<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3751<div class="doc_subsubsection">
3752 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3753</div>
3754
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3755<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3756
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3757<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3758<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3759 &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]3760</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3761
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3762<h5>Overview:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3763<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3764 currently executing function, to be automatically released when this function
3765 returns to its caller. The object is always allocated in the generic address
3766 space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3767
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3768<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3769<p>The '<tt>alloca</tt>' instruction
3770 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
3771 runtime stack, returning a pointer of the appropriate type to the program.
3772 If "NumElements" is specified, it is the number of elements allocated,
3773 otherwise "NumElements" is defaulted to be one. If a constant alignment is
3774 specified, the value result of the allocation is guaranteed to be aligned to
3775 at least that boundary. If not specified, or if zero, the target can choose
3776 to align the allocation on any convenient boundary compatible with the
3777 type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3778
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3779<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3780
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3781<h5>Semantics:</h5>
Bill Wendling871eb0a2009-05-08 20:49:29 +0000[diff] [blame]3782<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3783 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
3784 memory is automatically released when the function returns. The
3785 '<tt>alloca</tt>' instruction is commonly used to represent automatic
3786 variables that must have an address available. When the function returns
3787 (either with the <tt><a href="#i_ret">ret</a></tt>
3788 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
3789 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3790
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3791<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3792<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3793 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
3794 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3795 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
3796 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3797</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3798
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3799</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3800
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3801<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3802<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3803Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3804
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3805<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3806
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3807<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3808<pre>
3809 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]
3810 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]
3811</pre>
3812
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3813<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3814<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3815
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3816<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3817<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
3818 from which to load. The pointer must point to
3819 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
3820 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
3821 number or order of execution of this <tt>load</tt> with other
3822 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3823 instructions. </p>
3824
3825<p>The optional constant "align" argument specifies the alignment of the
3826 operation (that is, the alignment of the memory address). A value of 0 or an
3827 omitted "align" argument means that the operation has the preferential
3828 alignment for the target. It is the responsibility of the code emitter to
3829 ensure that the alignment information is correct. Overestimating the
3830 alignment results in an undefined behavior. Underestimating the alignment may
3831 produce less efficient code. An alignment of 1 is always safe.</p>
3832
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3833<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3834<p>The location of memory pointed to is loaded. If the value being loaded is of
3835 scalar type then the number of bytes read does not exceed the minimum number
3836 of bytes needed to hold all bits of the type. For example, loading an
3837 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
3838 <tt>i20</tt> with a size that is not an integral number of bytes, the result
3839 is undefined if the value was not originally written using a store of the
3840 same type.</p>
3841
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3842<h5>Examples:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3843<pre>
3844 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
3845 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3846 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3847</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3848
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3849</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3850
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3851<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3852<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3853Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3854
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]3855<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3856
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3857<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3858<pre>
3859 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]3860 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]3861</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3862
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3863<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3864<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3865
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3866<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3867<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
3868 and an address at which to store it. The type of the
3869 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
3870 the <a href="#t_firstclass">first class</a> type of the
3871 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked
3872 as <tt>volatile</tt>, then the optimizer is not allowed to modify the number
3873 or order of execution of this <tt>store</tt> with other
3874 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3875 instructions.</p>
3876
3877<p>The optional constant "align" argument specifies the alignment of the
3878 operation (that is, the alignment of the memory address). A value of 0 or an
3879 omitted "align" argument means that the operation has the preferential
3880 alignment for the target. It is the responsibility of the code emitter to
3881 ensure that the alignment information is correct. Overestimating the
3882 alignment results in an undefined behavior. Underestimating the alignment may
3883 produce less efficient code. An alignment of 1 is always safe.</p>
3884
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3885<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3886<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
3887 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
3888 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
3889 does not exceed the minimum number of bytes needed to hold all bits of the
3890 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
3891 writing a value of a type like <tt>i20</tt> with a size that is not an
3892 integral number of bytes, it is unspecified what happens to the extra bits
3893 that do not belong to the type, but they will typically be overwritten.</p>
3894
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3895<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3896<pre>
3897 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]3898 store i32 3, i32* %ptr <i>; yields {void}</i>
3899 %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]3900</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3901
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3902</div>
3903
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3904<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3905<div class="doc_subsubsection">
3906 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3907</div>
3908
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3909<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3910
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3911<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3912<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3913 &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]3914 &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]3915</pre>
3916
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3917<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3918<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
3919 subelement of an aggregate data structure. It performs address calculation
3920 only and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3921
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3922<h5>Arguments:</h5>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3923<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]3924 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3925 elements of the aggregate object are indexed. The interpretation of each
3926 index is dependent on the type being indexed into. The first index always
3927 indexes the pointer value given as the first argument, the second index
3928 indexes a value of the type pointed to (not necessarily the value directly
3929 pointed to, since the first index can be non-zero), etc. The first type
3930 indexed into must be a pointer value, subsequent types can be arrays, vectors
3931 and structs. Note that subsequent types being indexed into can never be
3932 pointers, since that would require loading the pointer before continuing
3933 calculation.</p>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3934
3935<p>The type of each index argument depends on the type it is indexing into.
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]3936 When indexing into a (optionally packed) structure, only <tt>i32</tt> integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3937 <b>constants</b> are allowed. When indexing into an array, pointer or
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]3938 vector, integers of any width are allowed, and they are not required to be
3939 constant.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3940
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3941<p>For example, let's consider a C code fragment and how it gets compiled to
3942 LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3943
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3944<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3945<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3946struct RT {
3947 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3948 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3949 char C;
3950};
3951struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3952 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3953 double Y;
3954 struct RT Z;
3955};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3956
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3957int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3958 return &amp;s[1].Z.B[5][13];
3959}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3960</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3961</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3962
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3963<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3964
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3965<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3966<pre>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]3967%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
3968%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3969
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]3970define i32* @foo(%ST* %s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3971entry:
3972 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3973 ret i32* %reg
3974}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3975</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3976</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3977
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3978<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3979<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]3980 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
3981 }</tt>' type, a structure. The second index indexes into the third element
3982 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3983 i8 }</tt>' type, another structure. The third index indexes into the second
3984 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
3985 array. The two dimensions of the array are subscripted into, yielding an
3986 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
3987 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3988
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3989<p>Note that it is perfectly legal to index partially through a structure,
3990 returning a pointer to an inner element. Because of this, the LLVM code for
3991 the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3992
3993<pre>
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]3994 define i32* @foo(%ST* %s) {
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3995 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3996 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3997 %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]3998 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3999 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4000 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4001 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4002</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]4003
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4004<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman0a28d182009-07-29 16:00:30 +0000[diff] [blame]4005 <tt>getelementptr</tt> is undefined if the base pointer is not an
4006 <i>in bounds</i> address of an allocated object, or if any of the addresses
4007 formed by successive addition of the offsets implied by the indices to
4008 the base address are not an <i>in bounds</i> address of that allocated
4009 object.
4010 The <i>in bounds</i> addresses for an allocated object are all the addresses
4011 that point into the object, plus the address one past the end.</p>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4012
4013<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4014 the base address with silently-wrapping two's complement arithmetic, and
4015 the result value of the <tt>getelementptr</tt> may be outside the object
4016 pointed to by the base pointer. The result value may not necessarily be
4017 used to access memory though, even if it happens to point into allocated
4018 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4019 section for more information.</p>
4020
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4021<p>The getelementptr instruction is often confusing. For some more insight into
4022 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4023
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4024<h5>Example:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4025<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4026 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4027 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4028 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4029 %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]4030 <i>; yields i8*:eptr</i>
4031 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta9f805c22009-04-25 07:27:44 +0000[diff] [blame]4032 <i>; yields i32*:iptr</i>
Sanjiv Gupta16ffa802009-04-24 16:38:13 +0000[diff] [blame]4033 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4034</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4035
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4036</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4037
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4038<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4039<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4040</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4041
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4042<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4043
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4044<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4045 which all take a single operand and a type. They perform various bit
4046 conversions on the operand.</p>
4047
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4048</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4049
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4050<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4051<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4052 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
4053</div>
4054<div class="doc_text">
4055
4056<h5>Syntax:</h5>
4057<pre>
4058 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4059</pre>
4060
4061<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4062<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4063 type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4064
4065<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4066<p>The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
4067 be an <a href="#t_integer">integer</a> type, and a type that specifies the
4068 size and type of the result, which must be
4069 an <a href="#t_integer">integer</a> type. The bit size of <tt>value</tt> must
4070 be larger than the bit size of <tt>ty2</tt>. Equal sized types are not
4071 allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4072
4073<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4074<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4075 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4076 source size must be larger than the destination size, <tt>trunc</tt> cannot
4077 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4078
4079<h5>Example:</h5>
4080<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4081 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4082 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
4083 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4084</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4085
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4086</div>
4087
4088<!-- _______________________________________________________________________ -->
4089<div class="doc_subsubsection">
4090 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
4091</div>
4092<div class="doc_text">
4093
4094<h5>Syntax:</h5>
4095<pre>
4096 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4097</pre>
4098
4099<h5>Overview:</h5>
4100<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4101 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4102
4103
4104<h5>Arguments:</h5>
4105<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]4106 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4107 also be of <a href="#t_integer">integer</a> type. The bit size of the
4108 <tt>value</tt> must be smaller than the bit size of the destination type,
4109 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4110
4111<h5>Semantics:</h5>
4112<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]4113 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4114
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]4115<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]4116
4117<h5>Example:</h5>
4118<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4119 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4120 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4121</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4122
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4123</div>
4124
4125<!-- _______________________________________________________________________ -->
4126<div class="doc_subsubsection">
4127 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
4128</div>
4129<div class="doc_text">
4130
4131<h5>Syntax:</h5>
4132<pre>
4133 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4134</pre>
4135
4136<h5>Overview:</h5>
4137<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4138
4139<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4140<p>The '<tt>sext</tt>' instruction takes a value to cast, which must be of
4141 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4142 also be of <a href="#t_integer">integer</a> type. The bit size of the
4143 <tt>value</tt> must be smaller than the bit size of the destination type,
4144 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4145
4146<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4147<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4148 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4149 of the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4150
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4151<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]4152
4153<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4154<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4155 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4156 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4157</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4158
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4159</div>
4160
4161<!-- _______________________________________________________________________ -->
4162<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4163 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
4164</div>
4165
4166<div class="doc_text">
4167
4168<h5>Syntax:</h5>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4169<pre>
4170 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4171</pre>
4172
4173<h5>Overview:</h5>
4174<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4175 <tt>ty2</tt>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4176
4177<h5>Arguments:</h5>
4178<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4179 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4180 to cast it to. The size of <tt>value</tt> must be larger than the size of
4181 <tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
4182 <i>no-op cast</i>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4183
4184<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4185<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
4186 <a href="#t_floating">floating point</a> type to a smaller
4187 <a href="#t_floating">floating point</a> type. If the value cannot fit
4188 within the destination type, <tt>ty2</tt>, then the results are
4189 undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4190
4191<h5>Example:</h5>
4192<pre>
4193 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4194 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4195</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4196
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4197</div>
4198
4199<!-- _______________________________________________________________________ -->
4200<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4201 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
4202</div>
4203<div class="doc_text">
4204
4205<h5>Syntax:</h5>
4206<pre>
4207 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4208</pre>
4209
4210<h5>Overview:</h5>
4211<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]4212 floating point value.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4213
4214<h5>Arguments:</h5>
4215<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4216 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4217 a <a href="#t_floating">floating point</a> type to cast it to. The source
4218 type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4219
4220<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4221<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4222 <a href="#t_floating">floating point</a> type to a larger
4223 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4224 used to make a <i>no-op cast</i> because it always changes bits. Use
4225 <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]4226
4227<h5>Example:</h5>
4228<pre>
4229 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
4230 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
4231</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4232
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4233</div>
4234
4235<!-- _______________________________________________________________________ -->
4236<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]4237 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4238</div>
4239<div class="doc_text">
4240
4241<h5>Syntax:</h5>
4242<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4243 &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]4244</pre>
4245
4246<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4247<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4248 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4249
4250<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4251<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4252 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4253 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4254 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4255 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4256
4257<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4258<p>The '<tt>fptoui</tt>' instruction converts its
4259 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4260 towards zero) unsigned integer value. If the value cannot fit
4261 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4262
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4263<h5>Example:</h5>
4264<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4265 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4266 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4267 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4268</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4269
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4270</div>
4271
4272<!-- _______________________________________________________________________ -->
4273<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4274 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4275</div>
4276<div class="doc_text">
4277
4278<h5>Syntax:</h5>
4279<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4280 &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]4281</pre>
4282
4283<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4284<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4285 <a href="#t_floating">floating point</a> <tt>value</tt> to
4286 type <tt>ty2</tt>.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4287
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4288<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4289<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4290 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4291 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4292 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4293 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4294
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4295<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4296<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4297 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4298 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4299 the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4300
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]4301<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4302<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4303 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4304 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4305 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4306</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4307
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4308</div>
4309
4310<!-- _______________________________________________________________________ -->
4311<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4312 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4313</div>
4314<div class="doc_text">
4315
4316<h5>Syntax:</h5>
4317<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4318 &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]4319</pre>
4320
4321<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4322<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4323 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4324
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4325<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]4326<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]4327 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4328 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4329 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4330 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4331
4332<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4333<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4334 integer quantity and converts it to the corresponding floating point
4335 value. If the value cannot fit in the floating point value, the results are
4336 undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4337
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4338<h5>Example:</h5>
4339<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4340 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4341 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4342</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4343
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4344</div>
4345
4346<!-- _______________________________________________________________________ -->
4347<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4348 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4349</div>
4350<div class="doc_text">
4351
4352<h5>Syntax:</h5>
4353<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4354 &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]4355</pre>
4356
4357<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4358<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
4359 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4360
4361<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]4362<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]4363 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4364 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4365 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4366 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4367
4368<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4369<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
4370 quantity and converts it to the corresponding floating point value. If the
4371 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4372
4373<h5>Example:</h5>
4374<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4375 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4376 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4377</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4378
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4379</div>
4380
4381<!-- _______________________________________________________________________ -->
4382<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4383 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
4384</div>
4385<div class="doc_text">
4386
4387<h5>Syntax:</h5>
4388<pre>
4389 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4390</pre>
4391
4392<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4393<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
4394 the integer type <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4395
4396<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4397<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
4398 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
4399 <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]4400
4401<h5>Semantics:</h5>
4402<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4403 <tt>ty2</tt> by interpreting the pointer value as an integer and either
4404 truncating or zero extending that value to the size of the integer type. If
4405 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
4406 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
4407 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
4408 change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4409
4410<h5>Example:</h5>
4411<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4412 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
4413 %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]4414</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4415
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4416</div>
4417
4418<!-- _______________________________________________________________________ -->
4419<div class="doc_subsubsection">
4420 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
4421</div>
4422<div class="doc_text">
4423
4424<h5>Syntax:</h5>
4425<pre>
4426 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4427</pre>
4428
4429<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4430<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
4431 pointer type, <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4432
4433<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4434<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4435 value to cast, and a type to cast it to, which must be a
4436 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4437
4438<h5>Semantics:</h5>
4439<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4440 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
4441 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
4442 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
4443 than the size of a pointer then a zero extension is done. If they are the
4444 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4445
4446<h5>Example:</h5>
4447<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4448 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
4449 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
4450 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4451</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4452
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4453</div>
4454
4455<!-- _______________________________________________________________________ -->
4456<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4457 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4458</div>
4459<div class="doc_text">
4460
4461<h5>Syntax:</h5>
4462<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4463 &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]4464</pre>
4465
4466<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4467<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4468 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4469
4470<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4471<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
4472 non-aggregate first class value, and a type to cast it to, which must also be
4473 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
4474 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
4475 identical. If the source type is a pointer, the destination type must also be
4476 a pointer. This instruction supports bitwise conversion of vectors to
4477 integers and to vectors of other types (as long as they have the same
4478 size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4479
4480<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4481<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4482 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
4483 this conversion. The conversion is done as if the <tt>value</tt> had been
4484 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
4485 be converted to other pointer types with this instruction. To convert
4486 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
4487 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4488
4489<h5>Example:</h5>
4490<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4491 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4492 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4493 %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]4494</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4495
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4496</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4497
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4498<!-- ======================================================================= -->
4499<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4500
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4501<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4502
4503<p>The instructions in this category are the "miscellaneous" instructions, which
4504 defy better classification.</p>
4505
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4506</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4507
4508<!-- _______________________________________________________________________ -->
4509<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4510</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4511
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4512<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4513
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4514<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4515<pre>
4516 &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]4517</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4518
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4519<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4520<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
4521 boolean values based on comparison of its two integer, integer vector, or
4522 pointer operands.</p>
4523
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4524<h5>Arguments:</h5>
4525<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4526 the condition code indicating the kind of comparison to perform. It is not a
4527 value, just a keyword. The possible condition code are:</p>
4528
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4529<ol>
4530 <li><tt>eq</tt>: equal</li>
4531 <li><tt>ne</tt>: not equal </li>
4532 <li><tt>ugt</tt>: unsigned greater than</li>
4533 <li><tt>uge</tt>: unsigned greater or equal</li>
4534 <li><tt>ult</tt>: unsigned less than</li>
4535 <li><tt>ule</tt>: unsigned less or equal</li>
4536 <li><tt>sgt</tt>: signed greater than</li>
4537 <li><tt>sge</tt>: signed greater or equal</li>
4538 <li><tt>slt</tt>: signed less than</li>
4539 <li><tt>sle</tt>: signed less or equal</li>
4540</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4541
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]4542<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4543 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
4544 typed. They must also be identical types.</p>
4545
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4546<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4547<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
4548 condition code given as <tt>cond</tt>. The comparison performed always yields
4549 either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt>
4550 result, as follows:</p>
4551
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4552<ol>
4553 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4554 <tt>false</tt> otherwise. No sign interpretation is necessary or
4555 performed.</li>
4556
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4557 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4558 <tt>false</tt> otherwise. No sign interpretation is necessary or
4559 performed.</li>
4560
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4561 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4562 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4563
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4564 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4565 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4566 to <tt>op2</tt>.</li>
4567
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4568 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4569 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4570
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4571 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4572 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4573
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4574 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4575 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4576
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4577 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4578 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4579 to <tt>op2</tt>.</li>
4580
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4581 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4582 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4583
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4584 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4585 <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]4586</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4587
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4588<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4589 values are compared as if they were integers.</p>
4590
4591<p>If the operands are integer vectors, then they are compared element by
4592 element. The result is an <tt>i1</tt> vector with the same number of elements
4593 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4594
4595<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4596<pre>
4597 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4598 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4599 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4600 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4601 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4602 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4603</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4604
4605<p>Note that the code generator does not yet support vector types with
4606 the <tt>icmp</tt> instruction.</p>
4607
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4608</div>
4609
4610<!-- _______________________________________________________________________ -->
4611<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4612</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4613
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4614<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4615
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4616<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4617<pre>
4618 &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]4619</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4620
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4621<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4622<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
4623 values based on comparison of its operands.</p>
4624
4625<p>If the operands are floating point scalars, then the result type is a boolean
4626(<a href="#t_primitive"><tt>i1</tt></a>).</p>
4627
4628<p>If the operands are floating point vectors, then the result type is a vector
4629 of boolean with the same number of elements as the operands being
4630 compared.</p>
4631
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4632<h5>Arguments:</h5>
4633<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4634 the condition code indicating the kind of comparison to perform. It is not a
4635 value, just a keyword. The possible condition code are:</p>
4636
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4637<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4638 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4639 <li><tt>oeq</tt>: ordered and equal</li>
4640 <li><tt>ogt</tt>: ordered and greater than </li>
4641 <li><tt>oge</tt>: ordered and greater than or equal</li>
4642 <li><tt>olt</tt>: ordered and less than </li>
4643 <li><tt>ole</tt>: ordered and less than or equal</li>
4644 <li><tt>one</tt>: ordered and not equal</li>
4645 <li><tt>ord</tt>: ordered (no nans)</li>
4646 <li><tt>ueq</tt>: unordered or equal</li>
4647 <li><tt>ugt</tt>: unordered or greater than </li>
4648 <li><tt>uge</tt>: unordered or greater than or equal</li>
4649 <li><tt>ult</tt>: unordered or less than </li>
4650 <li><tt>ule</tt>: unordered or less than or equal</li>
4651 <li><tt>une</tt>: unordered or not equal</li>
4652 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4653 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4654</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4655
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4656<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4657 <i>unordered</i> means that either operand may be a QNAN.</p>
4658
4659<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
4660 a <a href="#t_floating">floating point</a> type or
4661 a <a href="#t_vector">vector</a> of floating point type. They must have
4662 identical types.</p>
4663
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4664<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4665<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4666 according to the condition code given as <tt>cond</tt>. If the operands are
4667 vectors, then the vectors are compared element by element. Each comparison
4668 performed always yields an <a href="#t_primitive">i1</a> result, as
4669 follows:</p>
4670
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4671<ol>
4672 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4673
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4674 <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]4675 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
4676
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4677 <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]4678 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
4679
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4680 <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]4681 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
4682
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4683 <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]4684 <tt>op1</tt> is less than <tt>op2</tt>.</li>
4685
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4686 <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]4687 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4688
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4689 <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]4690 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
4691
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4692 <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]4693
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4694 <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]4695 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
4696
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4697 <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]4698 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4699
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4700 <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]4701 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
4702
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4703 <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]4704 <tt>op1</tt> is less than <tt>op2</tt>.</li>
4705
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4706 <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]4707 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4708
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4709 <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]4710 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
4711
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4712 <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]4713
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4714 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4715</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4716
4717<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4718<pre>
4719 &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]4720 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4721 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4722 &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]4723</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4724
4725<p>Note that the code generator does not yet support vector types with
4726 the <tt>fcmp</tt> instruction.</p>
4727
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4728</div>
4729
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4730<!-- _______________________________________________________________________ -->
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4731<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4732 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4733</div>
4734
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4735<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4736
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4737<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4738<pre>
4739 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
4740</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4741
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4742<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4743<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
4744 SSA graph representing the function.</p>
4745
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4746<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4747<p>The type of the incoming values is specified with the first type field. After
4748 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
4749 one pair for each predecessor basic block of the current block. Only values
4750 of <a href="#t_firstclass">first class</a> type may be used as the value
4751 arguments to the PHI node. Only labels may be used as the label
4752 arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4753
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4754<p>There must be no non-phi instructions between the start of a basic block and
4755 the PHI instructions: i.e. PHI instructions must be first in a basic
4756 block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4757
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4758<p>For the purposes of the SSA form, the use of each incoming value is deemed to
4759 occur on the edge from the corresponding predecessor block to the current
4760 block (but after any definition of an '<tt>invoke</tt>' instruction's return
4761 value on the same edge).</p>
Jay Foadd2449092009-06-03 10:20:10 +0000[diff] [blame]4762
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4763<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4764<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4765 specified by the pair corresponding to the predecessor basic block that
4766 executed just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4767
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4768<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4769<pre>
4770Loop: ; Infinite loop that counts from 0 on up...
4771 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4772 %nextindvar = add i32 %indvar, 1
4773 br label %Loop
4774</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4775
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4776</div>
4777
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4778<!-- _______________________________________________________________________ -->
4779<div class="doc_subsubsection">
4780 <a name="i_select">'<tt>select</tt>' Instruction</a>
4781</div>
4782
4783<div class="doc_text">
4784
4785<h5>Syntax:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4786<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4787 &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>
4788
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4789 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4790</pre>
4791
4792<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4793<p>The '<tt>select</tt>' instruction is used to choose one value based on a
4794 condition, without branching.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4795
4796
4797<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4798<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
4799 values indicating the condition, and two values of the
4800 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
4801 vectors and the condition is a scalar, then entire vectors are selected, not
4802 individual elements.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4803
4804<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4805<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
4806 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4807
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4808<p>If the condition is a vector of i1, then the value arguments must be vectors
4809 of the same size, and the selection is done element by element.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4810
4811<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4812<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4813 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4814</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4815
4816<p>Note that the code generator does not yet support conditions
4817 with vector type.</p>
4818
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4819</div>
4820
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]4821<!-- _______________________________________________________________________ -->
4822<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4823 <a name="i_call">'<tt>call</tt>' Instruction</a>
4824</div>
4825
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4826<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4827
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4828<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4829<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]4830 &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]4831</pre>
4832
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4833<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4834<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4835
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4836<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4837<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4838
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4839<ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4840 <li>The optional "tail" marker indicates whether the callee function accesses
4841 any allocas or varargs in the caller. If the "tail" marker is present,
4842 the function call is eligible for tail call optimization. Note that calls
4843 may be marked "tail" even if they do not occur before
4844 a <a href="#i_ret"><tt>ret</tt></a> instruction.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4845
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4846 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
4847 convention</a> the call should use. If none is specified, the call
4848 defaults to using C calling conventions.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4849
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4850 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4851 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
4852 '<tt>inreg</tt>' attributes are valid here.</li>
4853
4854 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
4855 type of the return value. Functions that return no value are marked
4856 <tt><a href="#t_void">void</a></tt>.</li>
4857
4858 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
4859 being invoked. The argument types must match the types implied by this
4860 signature. This type can be omitted if the function is not varargs and if
4861 the function type does not return a pointer to a function.</li>
4862
4863 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4864 be invoked. In most cases, this is a direct function invocation, but
4865 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
4866 to function value.</li>
4867
4868 <li>'<tt>function args</tt>': argument list whose types match the function
4869 signature argument types. All arguments must be of
4870 <a href="#t_firstclass">first class</a> type. If the function signature
4871 indicates the function accepts a variable number of arguments, the extra
4872 arguments can be specified.</li>
4873
4874 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
4875 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
4876 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4877</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4878
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4879<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4880<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
4881 a specified function, with its incoming arguments bound to the specified
4882 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
4883 function, control flow continues with the instruction after the function
4884 call, and the return value of the function is bound to the result
4885 argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4886
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4887<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4888<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4889 %retval = call i32 @test(i32 %argc)
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]4890 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4891 %X = tail call i32 @foo() <i>; yields i32</i>
4892 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4893 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]4894
4895 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4896 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]4897 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
4898 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]4899 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]4900 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4901</pre>
4902
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4903</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4904
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4905<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4906<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]4907 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4908</div>
4909
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4910<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4911
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4912<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4913<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4914 &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]4915</pre>
4916
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4917<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4918<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4919 the "variable argument" area of a function call. It is used to implement the
4920 <tt>va_arg</tt> macro in C.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4921
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4922<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4923<p>This instruction takes a <tt>va_list*</tt> value and the type of the
4924 argument. It returns a value of the specified argument type and increments
4925 the <tt>va_list</tt> to point to the next argument. The actual type
4926 of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4927
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4928<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4929<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
4930 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
4931 to the next argument. For more information, see the variable argument
4932 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4933
4934<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]4935 take a variable number of arguments, for example, the <tt>vfprintf</tt>
4936 function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4937
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4938<p><tt>va_arg</tt> is an LLVM instruction instead of
4939 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
4940 argument.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4941
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4942<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4943<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4944
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4945<p>Note that the code generator does not yet fully support va_arg on many
4946 targets. Also, it does not currently support va_arg with aggregate types on
4947 any target.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]4948
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4949</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4950
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4951<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4952<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4953<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4954
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4955<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4956
4957<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4958 well known names and semantics and are required to follow certain
4959 restrictions. Overall, these intrinsics represent an extension mechanism for
4960 the LLVM language that does not require changing all of the transformations
4961 in LLVM when adding to the language (or the bitcode reader/writer, the
4962 parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4963
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4964<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4965 prefix is reserved in LLVM for intrinsic names; thus, function names may not
4966 begin with this prefix. Intrinsic functions must always be external
4967 functions: you cannot define the body of intrinsic functions. Intrinsic
4968 functions may only be used in call or invoke instructions: it is illegal to
4969 take the address of an intrinsic function. Additionally, because intrinsic
4970 functions are part of the LLVM language, it is required if any are added that
4971 they be documented here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4972
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4973<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
4974 family of functions that perform the same operation but on different data
4975 types. Because LLVM can represent over 8 million different integer types,
4976 overloading is used commonly to allow an intrinsic function to operate on any
4977 integer type. One or more of the argument types or the result type can be
4978 overloaded to accept any integer type. Argument types may also be defined as
4979 exactly matching a previous argument's type or the result type. This allows
4980 an intrinsic function which accepts multiple arguments, but needs all of them
4981 to be of the same type, to only be overloaded with respect to a single
4982 argument or the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4983
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4984<p>Overloaded intrinsics will have the names of its overloaded argument types
4985 encoded into its function name, each preceded by a period. Only those types
4986 which are overloaded result in a name suffix. Arguments whose type is matched
4987 against another type do not. For example, the <tt>llvm.ctpop</tt> function
4988 can take an integer of any width and returns an integer of exactly the same
4989 integer width. This leads to a family of functions such as
4990 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
4991 %val)</tt>. Only one type, the return type, is overloaded, and only one type
4992 suffix is required. Because the argument's type is matched against the return
4993 type, it does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4994
4995<p>To learn how to add an intrinsic function, please see the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4996 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4997
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4998</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4999
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5000<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5001<div class="doc_subsection">
5002 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
5003</div>
5004
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5005<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5006
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5007<p>Variable argument support is defined in LLVM with
5008 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5009 intrinsic functions. These functions are related to the similarly named
5010 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5011
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5012<p>All of these functions operate on arguments that use a target-specific value
5013 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5014 not define what this type is, so all transformations should be prepared to
5015 handle these functions regardless of the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5016
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]5017<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]5018 instruction and the variable argument handling intrinsic functions are
5019 used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5020
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5021<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5022<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5023define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5024 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5025 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5026 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5027 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5028
5029 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5030 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5031
5032 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5033 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5034 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5035 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5036 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5037
5038 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5039 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5040 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5041}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5042
5043declare void @llvm.va_start(i8*)
5044declare void @llvm.va_copy(i8*, i8*)
5045declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5046</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5047</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5048
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5049</div>
5050
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5051<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5052<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5053 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5054</div>
5055
5056
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5057<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5058
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5059<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5060<pre>
5061 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5062</pre>
5063
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5064<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5065<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5066 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]5067
5068<h5>Arguments:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5069<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]5070
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5071<h5>Semantics:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5072<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]5073 macro available in C. In a target-dependent way, it initializes
5074 the <tt>va_list</tt> element to which the argument points, so that the next
5075 call to <tt>va_arg</tt> will produce the first variable argument passed to
5076 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5077 need to know the last argument of the function as the compiler can figure
5078 that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5079
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5080</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5081
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5082<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5083<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5084 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5085</div>
5086
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5087<div class="doc_text">
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5088
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5089<h5>Syntax:</h5>
5090<pre>
5091 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5092</pre>
5093
5094<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5095<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5096 which has been initialized previously
5097 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5098 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5099
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5100<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5101<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]5102
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5103<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5104<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]5105 macro available in C. In a target-dependent way, it destroys
5106 the <tt>va_list</tt> element to which the argument points. Calls
5107 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5108 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5109 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5110
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5111</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5112
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5113<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5114<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5115 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5116</div>
5117
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5118<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5119
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5120<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5121<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5122 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5123</pre>
5124
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5125<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5126<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5127 from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5128
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5129<h5>Arguments:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5130<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]5131 The second argument is a pointer to a <tt>va_list</tt> element to copy
5132 from.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5133
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5134<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5135<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]5136 macro available in C. In a target-dependent way, it copies the
5137 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5138 element. This intrinsic is necessary because
5139 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5140 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5141
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5142</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5143
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5144<!-- ======================================================================= -->
5145<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5146 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
5147</div>
5148
5149<div class="doc_text">
5150
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5151<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5152Collection</a> (GC) requires the implementation and generation of these
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5153intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5154roots on the stack</a>, as well as garbage collector implementations that
5155require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5156barriers. Front-ends for type-safe garbage collected languages should generate
5157these intrinsics to make use of the LLVM garbage collectors. For more details,
5158see <a href="GarbageCollection.html">Accurate Garbage Collection with
5159LLVM</a>.</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5160
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5161<p>The garbage collection intrinsics only operate on objects in the generic
5162 address space (address space zero).</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5163
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5164</div>
5165
5166<!-- _______________________________________________________________________ -->
5167<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5168 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5169</div>
5170
5171<div class="doc_text">
5172
5173<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5174<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5175 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5176</pre>
5177
5178<h5>Overview:</h5>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]5179<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]5180 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5181
5182<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5183<p>The first argument specifies the address of a stack object that contains the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5184 root pointer. The second pointer (which must be either a constant or a
5185 global value address) contains the meta-data to be associated with the
5186 root.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5187
5188<h5>Semantics:</h5>
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]5189<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]5190 location. At compile-time, the code generator generates information to allow
5191 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5192 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5193 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5194
5195</div>
5196
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5197<!-- _______________________________________________________________________ -->
5198<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5199 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5200</div>
5201
5202<div class="doc_text">
5203
5204<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5205<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5206 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5207</pre>
5208
5209<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5210<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5211 locations, allowing garbage collector implementations that require read
5212 barriers.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5213
5214<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5215<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]5216 allocated from the garbage collector. The first object is a pointer to the
5217 start of the referenced object, if needed by the language runtime (otherwise
5218 null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5219
5220<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5221<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5222 instruction, but may be replaced with substantially more complex code by the
5223 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5224 may only be used in a function which <a href="#gc">specifies a GC
5225 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5226
5227</div>
5228
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5229<!-- _______________________________________________________________________ -->
5230<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5231 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5232</div>
5233
5234<div class="doc_text">
5235
5236<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5237<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5238 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5239</pre>
5240
5241<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5242<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5243 locations, allowing garbage collector implementations that require write
5244 barriers (such as generational or reference counting collectors).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5245
5246<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5247<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]5248 object to store it to, and the third is the address of the field of Obj to
5249 store to. If the runtime does not require a pointer to the object, Obj may
5250 be null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5251
5252<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5253<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5254 instruction, but may be replaced with substantially more complex code by the
5255 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5256 may only be used in a function which <a href="#gc">specifies a GC
5257 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5258
5259</div>
5260
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5261<!-- ======================================================================= -->
5262<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5263 <a name="int_codegen">Code Generator Intrinsics</a>
5264</div>
5265
5266<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5267
5268<p>These intrinsics are provided by LLVM to expose special features that may
5269 only be implemented with code generator support.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5270
5271</div>
5272
5273<!-- _______________________________________________________________________ -->
5274<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5275 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5276</div>
5277
5278<div class="doc_text">
5279
5280<h5>Syntax:</h5>
5281<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5282 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5283</pre>
5284
5285<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5286<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5287 target-specific value indicating the return address of the current function
5288 or one of its callers.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5289
5290<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5291<p>The argument to this intrinsic indicates which function to return the address
5292 for. Zero indicates the calling function, one indicates its caller, etc.
5293 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5294
5295<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5296<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5297 indicating the return address of the specified call frame, or zero if it
5298 cannot be identified. The value returned by this intrinsic is likely to be
5299 incorrect or 0 for arguments other than zero, so it should only be used for
5300 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5301
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5302<p>Note that calling this intrinsic does not prevent function inlining or other
5303 aggressive transformations, so the value returned may not be that of the
5304 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5305
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5306</div>
5307
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5308<!-- _______________________________________________________________________ -->
5309<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5310 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5311</div>
5312
5313<div class="doc_text">
5314
5315<h5>Syntax:</h5>
5316<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5317 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5318</pre>
5319
5320<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5321<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5322 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5323
5324<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5325<p>The argument to this intrinsic indicates which function to return the frame
5326 pointer for. Zero indicates the calling function, one indicates its caller,
5327 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5328
5329<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5330<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
5331 indicating the frame address of the specified call frame, or zero if it
5332 cannot be identified. The value returned by this intrinsic is likely to be
5333 incorrect or 0 for arguments other than zero, so it should only be used for
5334 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5335
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5336<p>Note that calling this intrinsic does not prevent function inlining or other
5337 aggressive transformations, so the value returned may not be that of the
5338 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5339
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5340</div>
5341
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5342<!-- _______________________________________________________________________ -->
5343<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5344 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5345</div>
5346
5347<div class="doc_text">
5348
5349<h5>Syntax:</h5>
5350<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5351 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5352</pre>
5353
5354<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5355<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
5356 of the function stack, for use
5357 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
5358 useful for implementing language features like scoped automatic variable
5359 sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5360
5361<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5362<p>This intrinsic returns a opaque pointer value that can be passed
5363 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
5364 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
5365 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
5366 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
5367 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
5368 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5369
5370</div>
5371
5372<!-- _______________________________________________________________________ -->
5373<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5374 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5375</div>
5376
5377<div class="doc_text">
5378
5379<h5>Syntax:</h5>
5380<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5381 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5382</pre>
5383
5384<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5385<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5386 the function stack to the state it was in when the
5387 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
5388 executed. This is useful for implementing language features like scoped
5389 automatic variable sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5390
5391<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5392<p>See the description
5393 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5394
5395</div>
5396
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5397<!-- _______________________________________________________________________ -->
5398<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5399 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5400</div>
5401
5402<div class="doc_text">
5403
5404<h5>Syntax:</h5>
5405<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5406 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]5407</pre>
5408
5409<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5410<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
5411 insert a prefetch instruction if supported; otherwise, it is a noop.
5412 Prefetches have no effect on the behavior of the program but can change its
5413 performance characteristics.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5414
5415<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5416<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
5417 specifier determining if the fetch should be for a read (0) or write (1),
5418 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
5419 locality, to (3) - extremely local keep in cache. The <tt>rw</tt>
5420 and <tt>locality</tt> arguments must be constant integers.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5421
5422<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5423<p>This intrinsic does not modify the behavior of the program. In particular,
5424 prefetches cannot trap and do not produce a value. On targets that support
5425 this intrinsic, the prefetch can provide hints to the processor cache for
5426 better performance.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5427
5428</div>
5429
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5430<!-- _______________________________________________________________________ -->
5431<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5432 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5433</div>
5434
5435<div class="doc_text">
5436
5437<h5>Syntax:</h5>
5438<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5439 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5440</pre>
5441
5442<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5443<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
5444 Counter (PC) in a region of code to simulators and other tools. The method
5445 is target specific, but it is expected that the marker will use exported
5446 symbols to transmit the PC of the marker. The marker makes no guarantees
5447 that it will remain with any specific instruction after optimizations. It is
5448 possible that the presence of a marker will inhibit optimizations. The
5449 intended use is to be inserted after optimizations to allow correlations of
5450 simulation runs.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5451
5452<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5453<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5454
5455<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5456<p>This intrinsic does not modify the behavior of the program. Backends that do
5457 not support this intrinisic may ignore it.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5458
5459</div>
5460
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5461<!-- _______________________________________________________________________ -->
5462<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5463 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5464</div>
5465
5466<div class="doc_text">
5467
5468<h5>Syntax:</h5>
5469<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5470 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5471</pre>
5472
5473<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5474<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5475 counter register (or similar low latency, high accuracy clocks) on those
5476 targets that support it. On X86, it should map to RDTSC. On Alpha, it
5477 should map to RPCC. As the backing counters overflow quickly (on the order
5478 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5479
5480<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5481<p>When directly supported, reading the cycle counter should not modify any
5482 memory. Implementations are allowed to either return a application specific
5483 value or a system wide value. On backends without support, this is lowered
5484 to a constant 0.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5485
5486</div>
5487
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5488<!-- ======================================================================= -->
5489<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5490 <a name="int_libc">Standard C Library Intrinsics</a>
5491</div>
5492
5493<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5494
5495<p>LLVM provides intrinsics for a few important standard C library functions.
5496 These intrinsics allow source-language front-ends to pass information about
5497 the alignment of the pointer arguments to the code generator, providing
5498 opportunity for more efficient code generation.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5499
5500</div>
5501
5502<!-- _______________________________________________________________________ -->
5503<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5504 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5505</div>
5506
5507<div class="doc_text">
5508
5509<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5510<p>This is an overloaded intrinsic. You can use <tt>llvm.memcpy</tt> on any
5511 integer bit width. Not all targets support all bit widths however.</p>
5512
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5513<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5514 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5515 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5516 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5517 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5518 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5519 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5520 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5521 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5522</pre>
5523
5524<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5525<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5526 source location to the destination location.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5527
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5528<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5529 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5530
5531<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5532<p>The first argument is a pointer to the destination, the second is a pointer
5533 to the source. The third argument is an integer argument specifying the
5534 number of bytes to copy, and the fourth argument is the alignment of the
5535 source and destination locations.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5536
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5537<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5538 then the caller guarantees that both the source and destination pointers are
5539 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5540
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5541<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5542<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5543 source location to the destination location, which are not allowed to
5544 overlap. It copies "len" bytes of memory over. If the argument is known to
5545 be aligned to some boundary, this can be specified as the fourth argument,
5546 otherwise it should be set to 0 or 1.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5547
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5548</div>
5549
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5550<!-- _______________________________________________________________________ -->
5551<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5552 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5553</div>
5554
5555<div class="doc_text">
5556
5557<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5558<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]5559 width. Not all targets support all bit widths however.</p>
5560
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5561<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5562 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5563 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5564 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5565 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5566 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5567 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5568 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5569 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5570</pre>
5571
5572<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5573<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
5574 source location to the destination location. It is similar to the
5575 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
5576 overlap.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5577
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5578<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5579 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5580
5581<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5582<p>The first argument is a pointer to the destination, the second is a pointer
5583 to the source. The third argument is an integer argument specifying the
5584 number of bytes to copy, and the fourth argument is the alignment of the
5585 source and destination locations.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5586
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5587<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5588 then the caller guarantees that the source and destination pointers are
5589 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5590
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5591<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5592<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
5593 source location to the destination location, which may overlap. It copies
5594 "len" bytes of memory over. If the argument is known to be aligned to some
5595 boundary, this can be specified as the fourth argument, otherwise it should
5596 be set to 0 or 1.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5597
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5598</div>
5599
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5600<!-- _______________________________________________________________________ -->
5601<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5602 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5603</div>
5604
5605<div class="doc_text">
5606
5607<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5608<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]5609 width. Not all targets support all bit widths however.</p>
5610
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5611<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5612 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5613 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5614 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5615 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5616 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5617 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5618 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5619 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5620</pre>
5621
5622<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5623<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
5624 particular byte value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5625
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5626<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
5627 intrinsic does not return a value, and takes an extra alignment argument.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5628
5629<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5630<p>The first argument is a pointer to the destination to fill, the second is the
5631 byte value to fill it with, the third argument is an integer argument
5632 specifying the number of bytes to fill, and the fourth argument is the known
5633 alignment of destination location.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5634
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5635<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5636 then the caller guarantees that the destination pointer is aligned to that
5637 boundary.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5638
5639<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5640<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
5641 at the destination location. If the argument is known to be aligned to some
5642 boundary, this can be specified as the fourth argument, otherwise it should
5643 be set to 0 or 1.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5644
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5645</div>
5646
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5647<!-- _______________________________________________________________________ -->
5648<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5649 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5650</div>
5651
5652<div class="doc_text">
5653
5654<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5655<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
5656 floating point or vector of floating point type. Not all targets support all
5657 types however.</p>
5658
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5659<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5660 declare float @llvm.sqrt.f32(float %Val)
5661 declare double @llvm.sqrt.f64(double %Val)
5662 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5663 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5664 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5665</pre>
5666
5667<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5668<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
5669 returning the same value as the libm '<tt>sqrt</tt>' functions would.
5670 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
5671 behavior for negative numbers other than -0.0 (which allows for better
5672 optimization, because there is no need to worry about errno being
5673 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]5674
5675<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5676<p>The argument and return value are floating point numbers of the same
5677 type.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5678
5679<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5680<p>This function returns the sqrt of the specified operand if it is a
5681 nonnegative floating point number.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5682
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5683</div>
5684
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5685<!-- _______________________________________________________________________ -->
5686<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5687 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5688</div>
5689
5690<div class="doc_text">
5691
5692<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5693<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
5694 floating point or vector of floating point type. Not all targets support all
5695 types however.</p>
5696
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5697<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5698 declare float @llvm.powi.f32(float %Val, i32 %power)
5699 declare double @llvm.powi.f64(double %Val, i32 %power)
5700 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5701 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5702 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5703</pre>
5704
5705<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5706<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5707 specified (positive or negative) power. The order of evaluation of
5708 multiplications is not defined. When a vector of floating point type is
5709 used, the second argument remains a scalar integer value.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5710
5711<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5712<p>The second argument is an integer power, and the first is a value to raise to
5713 that power.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5714
5715<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5716<p>This function returns the first value raised to the second power with an
5717 unspecified sequence of rounding operations.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5718
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5719</div>
5720
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5721<!-- _______________________________________________________________________ -->
5722<div class="doc_subsubsection">
5723 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5724</div>
5725
5726<div class="doc_text">
5727
5728<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5729<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5730 floating point or vector of floating point type. Not all targets support all
5731 types however.</p>
5732
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5733<pre>
5734 declare float @llvm.sin.f32(float %Val)
5735 declare double @llvm.sin.f64(double %Val)
5736 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5737 declare fp128 @llvm.sin.f128(fp128 %Val)
5738 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5739</pre>
5740
5741<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5742<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5743
5744<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5745<p>The argument and return value are floating point numbers of the same
5746 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5747
5748<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5749<p>This function returns the sine of the specified operand, returning the same
5750 values as the libm <tt>sin</tt> functions would, and handles error conditions
5751 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5752
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5753</div>
5754
5755<!-- _______________________________________________________________________ -->
5756<div class="doc_subsubsection">
5757 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5758</div>
5759
5760<div class="doc_text">
5761
5762<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5763<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5764 floating point or vector of floating point type. Not all targets support all
5765 types however.</p>
5766
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5767<pre>
5768 declare float @llvm.cos.f32(float %Val)
5769 declare double @llvm.cos.f64(double %Val)
5770 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5771 declare fp128 @llvm.cos.f128(fp128 %Val)
5772 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5773</pre>
5774
5775<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5776<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5777
5778<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5779<p>The argument and return value are floating point numbers of the same
5780 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5781
5782<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5783<p>This function returns the cosine of the specified operand, returning the same
5784 values as the libm <tt>cos</tt> functions would, and handles error conditions
5785 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5786
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5787</div>
5788
5789<!-- _______________________________________________________________________ -->
5790<div class="doc_subsubsection">
5791 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5792</div>
5793
5794<div class="doc_text">
5795
5796<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5797<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5798 floating point or vector of floating point type. Not all targets support all
5799 types however.</p>
5800
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5801<pre>
5802 declare float @llvm.pow.f32(float %Val, float %Power)
5803 declare double @llvm.pow.f64(double %Val, double %Power)
5804 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5805 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5806 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5807</pre>
5808
5809<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5810<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5811 specified (positive or negative) power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5812
5813<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5814<p>The second argument is a floating point power, and the first is a value to
5815 raise to that power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5816
5817<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5818<p>This function returns the first value raised to the second power, returning
5819 the same values as the libm <tt>pow</tt> functions would, and handles error
5820 conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5821
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5822</div>
5823
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5824<!-- ======================================================================= -->
5825<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5826 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5827</div>
5828
5829<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5830
5831<p>LLVM provides intrinsics for a few important bit manipulation operations.
5832 These allow efficient code generation for some algorithms.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5833
5834</div>
5835
5836<!-- _______________________________________________________________________ -->
5837<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5838 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5839</div>
5840
5841<div class="doc_text">
5842
5843<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5844<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5845 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
5846
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5847<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5848 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5849 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5850 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5851</pre>
5852
5853<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5854<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
5855 values with an even number of bytes (positive multiple of 16 bits). These
5856 are useful for performing operations on data that is not in the target's
5857 native byte order.</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5858
5859<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5860<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
5861 and low byte of the input i16 swapped. Similarly,
5862 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
5863 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
5864 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
5865 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
5866 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
5867 more, respectively).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5868
5869</div>
5870
5871<!-- _______________________________________________________________________ -->
5872<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5873 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5874</div>
5875
5876<div class="doc_text">
5877
5878<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5879<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]5880 width. Not all targets support all bit widths however.</p>
5881
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5882<pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5883 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5884 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5885 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5886 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5887 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5888</pre>
5889
5890<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5891<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
5892 in a value.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5893
5894<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5895<p>The only argument is the value to be counted. The argument may be of any
5896 integer type. The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5897
5898<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5899<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]5900
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5901</div>
5902
5903<!-- _______________________________________________________________________ -->
5904<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5905 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5906</div>
5907
5908<div class="doc_text">
5909
5910<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5911<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
5912 integer bit width. Not all targets support all bit widths however.</p>
5913
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5914<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5915 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5916 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5917 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5918 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5919 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5920</pre>
5921
5922<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5923<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5924 leading zeros in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5925
5926<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5927<p>The only argument is the value to be counted. The argument may be of any
5928 integer type. The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5929
5930<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5931<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
5932 zeros in a variable. If the src == 0 then the result is the size in bits of
5933 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5934
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5935</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5936
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5937<!-- _______________________________________________________________________ -->
5938<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5939 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5940</div>
5941
5942<div class="doc_text">
5943
5944<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5945<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
5946 integer bit width. Not all targets support all bit widths however.</p>
5947
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5948<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5949 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5950 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5951 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5952 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5953 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5954</pre>
5955
5956<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5957<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5958 trailing zeros.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5959
5960<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5961<p>The only argument is the value to be counted. The argument may be of any
5962 integer type. The return type must match the argument type.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5963
5964<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5965<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
5966 zeros in a variable. If the src == 0 then the result is the size in bits of
5967 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5968
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5969</div>
5970
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5971<!-- ======================================================================= -->
5972<div class="doc_subsection">
5973 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
5974</div>
5975
5976<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5977
5978<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5979
5980</div>
5981
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5982<!-- _______________________________________________________________________ -->
5983<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5984 <a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5985</div>
5986
5987<div class="doc_text">
5988
5989<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5990<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]5991 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5992
5993<pre>
5994 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
5995 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
5996 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
5997</pre>
5998
5999<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6000<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6001 a signed addition of the two arguments, and indicate whether an overflow
6002 occurred during the signed summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6003
6004<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6005<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]6006 be of integer types of any bit width, but they must have the same bit
6007 width. The second element of the result structure must be of
6008 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6009 undergo signed addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6010
6011<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6012<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6013 a signed addition of the two variables. They return a structure &mdash; the
6014 first element of which is the signed summation, and the second element of
6015 which is a bit specifying if the signed summation resulted in an
6016 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6017
6018<h5>Examples:</h5>
6019<pre>
6020 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6021 %sum = extractvalue {i32, i1} %res, 0
6022 %obit = extractvalue {i32, i1} %res, 1
6023 br i1 %obit, label %overflow, label %normal
6024</pre>
6025
6026</div>
6027
6028<!-- _______________________________________________________________________ -->
6029<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6030 <a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6031</div>
6032
6033<div class="doc_text">
6034
6035<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6036<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]6037 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6038
6039<pre>
6040 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6041 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6042 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6043</pre>
6044
6045<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6046<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6047 an unsigned addition of the two arguments, and indicate whether a carry
6048 occurred during the unsigned summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6049
6050<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6051<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]6052 be of integer types of any bit width, but they must have the same bit
6053 width. The second element of the result structure must be of
6054 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6055 undergo unsigned addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6056
6057<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6058<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6059 an unsigned addition of the two arguments. They return a structure &mdash;
6060 the first element of which is the sum, and the second element of which is a
6061 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6062
6063<h5>Examples:</h5>
6064<pre>
6065 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6066 %sum = extractvalue {i32, i1} %res, 0
6067 %obit = extractvalue {i32, i1} %res, 1
6068 br i1 %obit, label %carry, label %normal
6069</pre>
6070
6071</div>
6072
6073<!-- _______________________________________________________________________ -->
6074<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6075 <a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6076</div>
6077
6078<div class="doc_text">
6079
6080<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6081<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]6082 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6083
6084<pre>
6085 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6086 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6087 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6088</pre>
6089
6090<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6091<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6092 a signed subtraction of the two arguments, and indicate whether an overflow
6093 occurred during the signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6094
6095<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6096<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]6097 be of integer types of any bit width, but they must have the same bit
6098 width. The second element of the result structure must be of
6099 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6100 undergo signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6101
6102<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6103<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6104 a signed subtraction of the two arguments. They return a structure &mdash;
6105 the first element of which is the subtraction, and the second element of
6106 which is a bit specifying if the signed subtraction resulted in an
6107 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6108
6109<h5>Examples:</h5>
6110<pre>
6111 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6112 %sum = extractvalue {i32, i1} %res, 0
6113 %obit = extractvalue {i32, i1} %res, 1
6114 br i1 %obit, label %overflow, label %normal
6115</pre>
6116
6117</div>
6118
6119<!-- _______________________________________________________________________ -->
6120<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6121 <a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6122</div>
6123
6124<div class="doc_text">
6125
6126<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6127<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]6128 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6129
6130<pre>
6131 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6132 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6133 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6134</pre>
6135
6136<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6137<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6138 an unsigned subtraction of the two arguments, and indicate whether an
6139 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6140
6141<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6142<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]6143 be of integer types of any bit width, but they must have the same bit
6144 width. The second element of the result structure must be of
6145 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6146 undergo unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6147
6148<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6149<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6150 an unsigned subtraction of the two arguments. They return a structure &mdash;
6151 the first element of which is the subtraction, and the second element of
6152 which is a bit specifying if the unsigned subtraction resulted in an
6153 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6154
6155<h5>Examples:</h5>
6156<pre>
6157 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6158 %sum = extractvalue {i32, i1} %res, 0
6159 %obit = extractvalue {i32, i1} %res, 1
6160 br i1 %obit, label %overflow, label %normal
6161</pre>
6162
6163</div>
6164
6165<!-- _______________________________________________________________________ -->
6166<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6167 <a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6168</div>
6169
6170<div class="doc_text">
6171
6172<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6173<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]6174 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6175
6176<pre>
6177 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6178 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6179 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6180</pre>
6181
6182<h5>Overview:</h5>
6183
6184<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6185 a signed multiplication of the two arguments, and indicate whether an
6186 overflow occurred during the signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6187
6188<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6189<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]6190 be of integer types of any bit width, but they must have the same bit
6191 width. The second element of the result structure must be of
6192 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6193 undergo signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6194
6195<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6196<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6197 a signed multiplication of the two arguments. They return a structure &mdash;
6198 the first element of which is the multiplication, and the second element of
6199 which is a bit specifying if the signed multiplication resulted in an
6200 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6201
6202<h5>Examples:</h5>
6203<pre>
6204 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6205 %sum = extractvalue {i32, i1} %res, 0
6206 %obit = extractvalue {i32, i1} %res, 1
6207 br i1 %obit, label %overflow, label %normal
6208</pre>
6209
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]6210</div>
6211
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6212<!-- _______________________________________________________________________ -->
6213<div class="doc_subsubsection">
6214 <a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
6215</div>
6216
6217<div class="doc_text">
6218
6219<h5>Syntax:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6220<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]6221 on any integer bit width.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6222
6223<pre>
6224 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6225 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6226 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6227</pre>
6228
6229<h5>Overview:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6230<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6231 a unsigned multiplication of the two arguments, and indicate whether an
6232 overflow occurred during the unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6233
6234<h5>Arguments:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6235<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]6236 be of integer types of any bit width, but they must have the same bit
6237 width. The second element of the result structure must be of
6238 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6239 undergo unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6240
6241<h5>Semantics:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6242<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6243 an unsigned multiplication of the two arguments. They return a structure
6244 &mdash; the first element of which is the multiplication, and the second
6245 element of which is a bit specifying if the unsigned multiplication resulted
6246 in an overflow.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6247
6248<h5>Examples:</h5>
6249<pre>
6250 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6251 %sum = extractvalue {i32, i1} %res, 0
6252 %obit = extractvalue {i32, i1} %res, 1
6253 br i1 %obit, label %overflow, label %normal
6254</pre>
6255
6256</div>
6257
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6258<!-- ======================================================================= -->
6259<div class="doc_subsection">
6260 <a name="int_debugger">Debugger Intrinsics</a>
6261</div>
6262
6263<div class="doc_text">
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6264
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6265<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
6266 prefix), are described in
6267 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
6268 Level Debugging</a> document.</p>
6269
6270</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6271
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6272<!-- ======================================================================= -->
6273<div class="doc_subsection">
6274 <a name="int_eh">Exception Handling Intrinsics</a>
6275</div>
6276
6277<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6278
6279<p>The LLVM exception handling intrinsics (which all start with
6280 <tt>llvm.eh.</tt> prefix), are described in
6281 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
6282 Handling</a> document.</p>
6283
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6284</div>
6285
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6286<!-- ======================================================================= -->
6287<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6288 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6289</div>
6290
6291<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6292
6293<p>This intrinsic makes it possible to excise one parameter, marked with
6294 the <tt>nest</tt> attribute, from a function. The result is a callable
6295 function pointer lacking the nest parameter - the caller does not need to
6296 provide a value for it. Instead, the value to use is stored in advance in a
6297 "trampoline", a block of memory usually allocated on the stack, which also
6298 contains code to splice the nest value into the argument list. This is used
6299 to implement the GCC nested function address extension.</p>
6300
6301<p>For example, if the function is
6302 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
6303 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
6304 follows:</p>
6305
6306<div class="doc_code">
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6307<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6308 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
6309 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
6310 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
6311 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6312</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6313</div>
6314
6315<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
6316 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
6317
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6318</div>
6319
6320<!-- _______________________________________________________________________ -->
6321<div class="doc_subsubsection">
6322 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
6323</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6324
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6325<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6326
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6327<h5>Syntax:</h5>
6328<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6329 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]6330</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6331
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6332<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6333<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
6334 function pointer suitable for executing it.</p>
6335
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6336<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6337<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
6338 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
6339 sufficiently aligned block of memory; this memory is written to by the
6340 intrinsic. Note that the size and the alignment are target-specific - LLVM
6341 currently provides no portable way of determining them, so a front-end that
6342 generates this intrinsic needs to have some target-specific knowledge.
6343 The <tt>func</tt> argument must hold a function bitcast to
6344 an <tt>i8*</tt>.</p>
6345
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6346<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6347<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
6348 dependent code, turning it into a function. A pointer to this function is
6349 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
6350 function pointer type</a> before being called. The new function's signature
6351 is the same as that of <tt>func</tt> with any arguments marked with
6352 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
6353 is allowed, and it must be of pointer type. Calling the new function is
6354 equivalent to calling <tt>func</tt> with the same argument list, but
6355 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
6356 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
6357 by <tt>tramp</tt> is modified, then the effect of any later call to the
6358 returned function pointer is undefined.</p>
6359
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6360</div>
6361
6362<!-- ======================================================================= -->
6363<div class="doc_subsection">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6364 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
6365</div>
6366
6367<div class="doc_text">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6368
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6369<p>These intrinsic functions expand the "universal IR" of LLVM to represent
6370 hardware constructs for atomic operations and memory synchronization. This
6371 provides an interface to the hardware, not an interface to the programmer. It
6372 is aimed at a low enough level to allow any programming models or APIs
6373 (Application Programming Interfaces) which need atomic behaviors to map
6374 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
6375 hardware provides a "universal IR" for source languages, it also provides a
6376 starting point for developing a "universal" atomic operation and
6377 synchronization IR.</p>
6378
6379<p>These do <em>not</em> form an API such as high-level threading libraries,
6380 software transaction memory systems, atomic primitives, and intrinsic
6381 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
6382 application libraries. The hardware interface provided by LLVM should allow
6383 a clean implementation of all of these APIs and parallel programming models.
6384 No one model or paradigm should be selected above others unless the hardware
6385 itself ubiquitously does so.</p>
6386
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6387</div>
6388
6389<!-- _______________________________________________________________________ -->
6390<div class="doc_subsubsection">
6391 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
6392</div>
6393<div class="doc_text">
6394<h5>Syntax:</h5>
6395<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6396 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]6397</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6398
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6399<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6400<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
6401 specific pairs of memory access types.</p>
6402
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6403<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6404<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
6405 The first four arguments enables a specific barrier as listed below. The
6406 fith argument specifies that the barrier applies to io or device or uncached
6407 memory.</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6408
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6409<ul>
6410 <li><tt>ll</tt>: load-load barrier</li>
6411 <li><tt>ls</tt>: load-store barrier</li>
6412 <li><tt>sl</tt>: store-load barrier</li>
6413 <li><tt>ss</tt>: store-store barrier</li>
6414 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
6415</ul>
6416
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6417<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6418<p>This intrinsic causes the system to enforce some ordering constraints upon
6419 the loads and stores of the program. This barrier does not
6420 indicate <em>when</em> any events will occur, it only enforces
6421 an <em>order</em> in which they occur. For any of the specified pairs of load
6422 and store operations (f.ex. load-load, or store-load), all of the first
6423 operations preceding the barrier will complete before any of the second
6424 operations succeeding the barrier begin. Specifically the semantics for each
6425 pairing is as follows:</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6426
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6427<ul>
6428 <li><tt>ll</tt>: All loads before the barrier must complete before any load
6429 after the barrier begins.</li>
6430 <li><tt>ls</tt>: All loads before the barrier must complete before any
6431 store after the barrier begins.</li>
6432 <li><tt>ss</tt>: All stores before the barrier must complete before any
6433 store after the barrier begins.</li>
6434 <li><tt>sl</tt>: All stores before the barrier must complete before any
6435 load after the barrier begins.</li>
6436</ul>
6437
6438<p>These semantics are applied with a logical "and" behavior when more than one
6439 is enabled in a single memory barrier intrinsic.</p>
6440
6441<p>Backends may implement stronger barriers than those requested when they do
6442 not support as fine grained a barrier as requested. Some architectures do
6443 not need all types of barriers and on such architectures, these become
6444 noops.</p>
6445
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6446<h5>Example:</h5>
6447<pre>
6448%ptr = malloc i32
6449 store i32 4, %ptr
6450
6451%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
6452 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
6453 <i>; guarantee the above finishes</i>
6454 store i32 8, %ptr <i>; before this begins</i>
6455</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6456
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6457</div>
6458
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6459<!-- _______________________________________________________________________ -->
6460<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6461 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6462</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6463
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6464<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6465
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6466<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6467<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
6468 any integer bit width and for different address spaces. Not all targets
6469 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6470
6471<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6472 declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6473 declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6474 declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
6475 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]6476</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6477
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6478<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6479<p>This loads a value in memory and compares it to a given value. If they are
6480 equal, it stores a new value into the memory.</p>
6481
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6482<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6483<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
6484 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
6485 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
6486 this integer type. While any bit width integer may be used, targets may only
6487 lower representations they support in hardware.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6488
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6489<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6490<p>This entire intrinsic must be executed atomically. It first loads the value
6491 in memory pointed to by <tt>ptr</tt> and compares it with the
6492 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
6493 memory. The loaded value is yielded in all cases. This provides the
6494 equivalent of an atomic compare-and-swap operation within the SSA
6495 framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6496
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6497<h5>Examples:</h5>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6498<pre>
6499%ptr = malloc i32
6500 store i32 4, %ptr
6501
6502%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6503%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6504 <i>; yields {i32}:result1 = 4</i>
6505%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6506%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6507
6508%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6509%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6510 <i>; yields {i32}:result2 = 8</i>
6511%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6512
6513%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6514</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6515
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6516</div>
6517
6518<!-- _______________________________________________________________________ -->
6519<div class="doc_subsubsection">
6520 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6521</div>
6522<div class="doc_text">
6523<h5>Syntax:</h5>
6524
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6525<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6526 integer bit width. Not all targets support all bit widths however.</p>
6527
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6528<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6529 declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6530 declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6531 declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6532 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]6533</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6534
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6535<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6536<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6537 the value from memory. It then stores the value in <tt>val</tt> in the memory
6538 at <tt>ptr</tt>.</p>
6539
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6540<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6541<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
6542 the <tt>val</tt> argument and the result must be integers of the same bit
6543 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6544 integer type. The targets may only lower integer representations they
6545 support.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6546
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6547<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6548<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6549 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6550 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6551
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6552<h5>Examples:</h5>
6553<pre>
6554%ptr = malloc i32
6555 store i32 4, %ptr
6556
6557%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6558%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6559 <i>; yields {i32}:result1 = 4</i>
6560%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6561%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6562
6563%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6564%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6565 <i>; yields {i32}:result2 = 8</i>
6566
6567%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6568%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6569</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6570
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6571</div>
6572
6573<!-- _______________________________________________________________________ -->
6574<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6575 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6576
6577</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6578
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6579<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6580
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6581<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6582<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
6583 any integer bit width. Not all targets support all bit widths however.</p>
6584
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6585<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6586 declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6587 declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6588 declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6589 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]6590</pre>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6591
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6592<h5>Overview:</h5>
6593<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
6594 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6595
6596<h5>Arguments:</h5>
6597<p>The intrinsic takes two arguments, the first a pointer to an integer value
6598 and the second an integer value. The result is also an integer value. These
6599 integer types can have any bit width, but they must all have the same bit
6600 width. The targets may only lower integer representations they support.</p>
6601
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6602<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6603<p>This intrinsic does a series of operations atomically. It first loads the
6604 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6605 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]6606
6607<h5>Examples:</h5>
6608<pre>
6609%ptr = malloc i32
6610 store i32 4, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6611%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6612 <i>; yields {i32}:result1 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6613%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6614 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6615%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6616 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6617%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6618</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6619
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6620</div>
6621
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6622<!-- _______________________________________________________________________ -->
6623<div class="doc_subsubsection">
6624 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6625
6626</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6627
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6628<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6629
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6630<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6631<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
6632 any integer bit width and for different address spaces. Not all targets
6633 support all bit widths however.</p>
6634
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6635<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6636 declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6637 declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6638 declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6639 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]6640</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6641
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6642<h5>Overview:</h5>
6643<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6644 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6645
6646<h5>Arguments:</h5>
6647<p>The intrinsic takes two arguments, the first a pointer to an integer value
6648 and the second an integer value. The result is also an integer value. These
6649 integer types can have any bit width, but they must all have the same bit
6650 width. The targets may only lower integer representations they support.</p>
6651
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6652<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6653<p>This intrinsic does a series of operations atomically. It first loads the
6654 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6655 result to <tt>ptr</tt>. It yields the original value stored
6656 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6657
6658<h5>Examples:</h5>
6659<pre>
6660%ptr = malloc i32
6661 store i32 8, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6662%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6663 <i>; yields {i32}:result1 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6664%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6665 <i>; yields {i32}:result2 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6666%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6667 <i>; yields {i32}:result3 = 2</i>
6668%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6669</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6670
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6671</div>
6672
6673<!-- _______________________________________________________________________ -->
6674<div class="doc_subsubsection">
6675 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6676 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6677 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6678 <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]6679</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6680
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6681<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6682
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6683<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6684<p>These are overloaded intrinsics. You can
6685 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
6686 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
6687 bit width and for different address spaces. Not all targets support all bit
6688 widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6689
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6690<pre>
6691 declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6692 declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6693 declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6694 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]6695</pre>
6696
6697<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6698 declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6699 declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6700 declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6701 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]6702</pre>
6703
6704<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6705 declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6706 declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6707 declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6708 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]6709</pre>
6710
6711<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6712 declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6713 declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6714 declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6715 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]6716</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6717
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6718<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6719<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6720 the value stored in memory at <tt>ptr</tt>. It yields the original value
6721 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6722
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6723<h5>Arguments:</h5>
6724<p>These intrinsics take two arguments, the first a pointer to an integer value
6725 and the second an integer value. The result is also an integer value. These
6726 integer types can have any bit width, but they must all have the same bit
6727 width. The targets may only lower integer representations they support.</p>
6728
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6729<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6730<p>These intrinsics does a series of operations atomically. They first load the
6731 value stored at <tt>ptr</tt>. They then do the bitwise
6732 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
6733 original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6734
6735<h5>Examples:</h5>
6736<pre>
6737%ptr = malloc i32
6738 store i32 0x0F0F, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6739%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6740 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6741%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6742 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6743%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6744 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6745%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6746 <i>; yields {i32}:result3 = FF</i>
6747%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6748</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6749
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6750</div>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6751
6752<!-- _______________________________________________________________________ -->
6753<div class="doc_subsubsection">
6754 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6755 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6756 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6757 <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]6758</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6759
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6760<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6761
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6762<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6763<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6764 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
6765 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6766 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6767
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6768<pre>
6769 declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6770 declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6771 declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6772 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]6773</pre>
6774
6775<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6776 declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6777 declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6778 declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6779 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]6780</pre>
6781
6782<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6783 declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6784 declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6785 declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6786 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]6787</pre>
6788
6789<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6790 declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6791 declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6792 declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6793 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]6794</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6795
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6796<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6797<p>These intrinsics takes the signed or unsigned minimum or maximum of
6798 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6799 original value at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6800
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6801<h5>Arguments:</h5>
6802<p>These intrinsics take two arguments, the first a pointer to an integer value
6803 and the second an integer value. The result is also an integer value. These
6804 integer types can have any bit width, but they must all have the same bit
6805 width. The targets may only lower integer representations they support.</p>
6806
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6807<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6808<p>These intrinsics does a series of operations atomically. They first load the
6809 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
6810 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
6811 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6812
6813<h5>Examples:</h5>
6814<pre>
6815%ptr = malloc i32
6816 store i32 7, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6817%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6818 <i>; yields {i32}:result0 = 7</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6819%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6820 <i>; yields {i32}:result1 = -2</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6821%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6822 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6823%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6824 <i>; yields {i32}:result3 = 8</i>
6825%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6826</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6827
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6828</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6829
6830<!-- ======================================================================= -->
6831<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6832 <a name="int_general">General Intrinsics</a>
6833</div>
6834
6835<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6836
6837<p>This class of intrinsics is designed to be generic and has no specific
6838 purpose.</p>
6839
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6840</div>
6841
6842<!-- _______________________________________________________________________ -->
6843<div class="doc_subsubsection">
6844 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6845</div>
6846
6847<div class="doc_text">
6848
6849<h5>Syntax:</h5>
6850<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]6851 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]6852</pre>
6853
6854<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6855<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6856
6857<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6858<p>The first argument is a pointer to a value, the second is a pointer to a
6859 global string, the third is a pointer to a global string which is the source
6860 file name, and the last argument is the line number.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6861
6862<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6863<p>This intrinsic allows annotation of local variables with arbitrary strings.
6864 This can be useful for special purpose optimizations that want to look for
6865 these annotations. These have no other defined use, they are ignored by code
6866 generation and optimization.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6867
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6868</div>
6869
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6870<!-- _______________________________________________________________________ -->
6871<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]6872 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6873</div>
6874
6875<div class="doc_text">
6876
6877<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6878<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6879 any integer bit width.</p>
6880
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6881<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]6882 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6883 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6884 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6885 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6886 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]6887</pre>
6888
6889<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6890<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6891
6892<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6893<p>The first argument is an integer value (result of some expression), the
6894 second is a pointer to a global string, the third is a pointer to a global
6895 string which is the source file name, and the last argument is the line
6896 number. It returns the value of the first argument.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6897
6898<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6899<p>This intrinsic allows annotations to be put on arbitrary expressions with
6900 arbitrary strings. This can be useful for special purpose optimizations that
6901 want to look for these annotations. These have no other defined use, they
6902 are ignored by code generation and optimization.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6903
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6904</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6905
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6906<!-- _______________________________________________________________________ -->
6907<div class="doc_subsubsection">
6908 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6909</div>
6910
6911<div class="doc_text">
6912
6913<h5>Syntax:</h5>
6914<pre>
6915 declare void @llvm.trap()
6916</pre>
6917
6918<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6919<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6920
6921<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6922<p>None.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6923
6924<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6925<p>This intrinsics is lowered to the target dependent trap instruction. If the
6926 target does not have a trap instruction, this intrinsic will be lowered to
6927 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6928
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6929</div>
6930
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6931<!-- _______________________________________________________________________ -->
6932<div class="doc_subsubsection">
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]6933 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6934</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6935
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6936<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6937
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6938<h5>Syntax:</h5>
6939<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6940 declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6941</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6942
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6943<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6944<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
6945 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
6946 ensure that it is placed on the stack before local variables.</p>
6947
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6948<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6949<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
6950 arguments. The first argument is the value loaded from the stack
6951 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
6952 that has enough space to hold the value of the guard.</p>
6953
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6954<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6955<p>This intrinsic causes the prologue/epilogue inserter to force the position of
6956 the <tt>AllocaInst</tt> stack slot to be before local variables on the
6957 stack. This is to ensure that if a local variable on the stack is
6958 overwritten, it will destroy the value of the guard. When the function exits,
6959 the guard on the stack is checked against the original guard. If they're
6960 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
6961 function.</p>
6962
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6963</div>
6964
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6965<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6966<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6967<address>
6968 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]6969 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6970 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]6971 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]6972
6973 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]6974 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6975 Last modified: $Date$
6976</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]6977
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6978</body>
6979</html>