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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 303dae993aba2474a23753ed66737b8c38cc97a0 / . / docs / LangRef.html
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5 <title>LLVM Assembly Language Reference Manual</title>
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7 <meta name="author" content="Chris Lattner">
8 <meta name="description"
9 content="LLVM Assembly Language Reference Manual.">
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11</head>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]14
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]15<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]16<ol>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]17 <li><a href="#abstract">Abstract</a></li>
18 <li><a href="#introduction">Introduction</a></li>
19 <li><a href="#identifiers">Identifiers</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]20 <li><a href="#highlevel">High Level Structure</a>
21 <ol>
22 <li><a href="#modulestructure">Module Structure</a></li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a></li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]24 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]25 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]26 <li><a href="#functionstructure">Functions</a></li>
Anton Korobeynikovc6c98af2007-04-29 18:02:48 +0000[diff] [blame]27 <li><a href="#aliasstructure">Aliases</a>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]28 <li><a href="#paramattrs">Parameter Attributes</a></li>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]29 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]30 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]31 <li><a href="#datalayout">Data Layout</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]32 </ol>
33 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]34 <li><a href="#typesystem">Type System</a>
35 <ol>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]36 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]37 <ol>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]38 <li><a href="#t_classifications">Type Classifications</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]39 </ol>
40 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]41 <li><a href="#t_derived">Derived Types</a>
42 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]43 <li><a href="#t_array">Array Type</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]44 <li><a href="#t_function">Function Type</a></li>
45 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]46 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]47 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]48 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]49 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]50 </ol>
51 </li>
52 </ol>
53 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]54 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]55 <ol>
56 <li><a href="#simpleconstants">Simple Constants</a>
57 <li><a href="#aggregateconstants">Aggregate Constants</a>
58 <li><a href="#globalconstants">Global Variable and Function Addresses</a>
59 <li><a href="#undefvalues">Undefined Values</a>
60 <li><a href="#constantexprs">Constant Expressions</a>
61 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]62 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]63 <li><a href="#othervalues">Other Values</a>
64 <ol>
65 <li><a href="#inlineasm">Inline Assembler Expressions</a>
66 </ol>
67 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]68 <li><a href="#instref">Instruction Reference</a>
69 <ol>
70 <li><a href="#terminators">Terminator Instructions</a>
71 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]72 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
73 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]74 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
75 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]76 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]77 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]78 </ol>
79 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]80 <li><a href="#binaryops">Binary Operations</a>
81 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]82 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
83 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
84 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]85 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
86 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
87 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]88 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
89 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
90 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]91 </ol>
92 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]93 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
94 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]95 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
96 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
97 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]98 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]99 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]100 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]101 </ol>
102 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]103 <li><a href="#vectorops">Vector Operations</a>
104 <ol>
105 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
106 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
107 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]108 </ol>
109 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]110 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]111 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]112 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
113 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
114 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]115 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
116 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
117 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]118 </ol>
119 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]120 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]121 <ol>
122 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
123 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
124 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
125 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
126 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]127 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
128 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
129 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
130 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]131 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
132 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]133 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]134 </ol>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]135 <li><a href="#otherops">Other Operations</a>
136 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]137 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
138 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]139 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]140 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]141 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]142 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]143 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]144 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]145 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]146 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]147 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]148 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]149 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
150 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]151 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
152 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
153 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]154 </ol>
155 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]156 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
157 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]158 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
159 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
160 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]161 </ol>
162 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]163 <li><a href="#int_codegen">Code Generator Intrinsics</a>
164 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]165 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
166 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
167 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
168 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
169 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
170 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
171 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]172 </ol>
173 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]174 <li><a href="#int_libc">Standard C Library Intrinsics</a>
175 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]176 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
177 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
178 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
179 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
180 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]181 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
182 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
183 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]184 </ol>
185 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]186 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]187 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]188 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]189 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
190 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
191 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]192 <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
193 <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]194 </ol>
195 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]196 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]197 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]198 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]199 <ol>
200 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]201 </ol>
202 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]203 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]204 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]205 <li><a href="#int_var_annotation">
Tanya Lattner91d0b882007-09-22 00:01:26 +0000[diff] [blame]206 <tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]207 </ol>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]208 <ol>
209 <li><a href="#int_annotation">
Tanya Lattner91d0b882007-09-22 00:01:26 +0000[diff] [blame]210 <tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]211 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]212 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]213 </ol>
214 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]215</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]216
217<div class="doc_author">
218 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
219 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]220</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]221
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]222<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]223<div class="doc_section"> <a name="abstract">Abstract </a></div>
224<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]225
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]226<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]227<p>This document is a reference manual for the LLVM assembly language.
228LLVM is an SSA based representation that provides type safety,
229low-level operations, flexibility, and the capability of representing
230'all' high-level languages cleanly. It is the common code
231representation used throughout all phases of the LLVM compilation
232strategy.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]233</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]234
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]235<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]236<div class="doc_section"> <a name="introduction">Introduction</a> </div>
237<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]238
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]239<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]240
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]241<p>The LLVM code representation is designed to be used in three
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]242different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]243representation (suitable for fast loading by a Just-In-Time compiler),
244and as a human readable assembly language representation. This allows
245LLVM to provide a powerful intermediate representation for efficient
246compiler transformations and analysis, while providing a natural means
247to debug and visualize the transformations. The three different forms
248of LLVM are all equivalent. This document describes the human readable
249representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]250
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]251<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]252while being expressive, typed, and extensible at the same time. It
253aims to be a "universal IR" of sorts, by being at a low enough level
254that high-level ideas may be cleanly mapped to it (similar to how
255microprocessors are "universal IR's", allowing many source languages to
256be mapped to them). By providing type information, LLVM can be used as
257the target of optimizations: for example, through pointer analysis, it
258can be proven that a C automatic variable is never accessed outside of
259the current function... allowing it to be promoted to a simple SSA
260value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]261
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]262</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]263
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]264<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]265<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]266
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]267<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]268
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]269<p>It is important to note that this document describes 'well formed'
270LLVM assembly language. There is a difference between what the parser
271accepts and what is considered 'well formed'. For example, the
272following instruction is syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]273
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]274<div class="doc_code">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]275<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]276%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]277</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]278</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]279
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]280<p>...because the definition of <tt>%x</tt> does not dominate all of
281its uses. The LLVM infrastructure provides a verification pass that may
282be used to verify that an LLVM module is well formed. This pass is
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]283automatically run by the parser after parsing input assembly and by
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]284the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]285by the verifier pass indicate bugs in transformation passes or input to
286the parser.</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]287</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]288
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]289<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]290
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]291<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]292<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]293<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]294
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]295<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]296
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]297 <p>LLVM identifiers come in two basic types: global and local. Global
298 identifiers (functions, global variables) begin with the @ character. Local
299 identifiers (register names, types) begin with the % character. Additionally,
300 there are three different formats for identifiers, for different purposes:
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]301
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]302<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]303 <li>Named values are represented as a string of characters with their prefix.
304 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
305 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]306 Identifiers which require other characters in their names can be surrounded
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]307 with quotes. In this way, anything except a <tt>&quot;</tt> character can
308 be used in a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]309
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]310 <li>Unnamed values are represented as an unsigned numeric value with their
311 prefix. For example, %12, @2, %44.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]312
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]313 <li>Constants, which are described in a <a href="#constants">section about
314 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]315</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]316
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]317<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]318don't need to worry about name clashes with reserved words, and the set of
319reserved words may be expanded in the future without penalty. Additionally,
320unnamed identifiers allow a compiler to quickly come up with a temporary
321variable without having to avoid symbol table conflicts.</p>
322
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]323<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]324languages. There are keywords for different opcodes
325('<tt><a href="#i_add">add</a></tt>',
326 '<tt><a href="#i_bitcast">bitcast</a></tt>',
327 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names ('<tt><a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]328href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]329and others. These reserved words cannot conflict with variable names, because
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]330none of them start with a prefix character ('%' or '@').</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]331
332<p>Here is an example of LLVM code to multiply the integer variable
333'<tt>%X</tt>' by 8:</p>
334
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]335<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]336
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]337<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]338<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]339%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]340</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]341</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]342
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]343<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]344
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]345<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]346<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]347%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]348</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]349</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]350
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]351<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]352
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]353<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]354<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]355<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
356<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
357%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]358</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]359</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]360
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]361<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
362important lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]363
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]364<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]365
366 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
367 line.</li>
368
369 <li>Unnamed temporaries are created when the result of a computation is not
370 assigned to a named value.</li>
371
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]372 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]373
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]374</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]375
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]376<p>...and it also shows a convention that we follow in this document. When
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]377demonstrating instructions, we will follow an instruction with a comment that
378defines the type and name of value produced. Comments are shown in italic
379text.</p>
380
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]381</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]382
383<!-- *********************************************************************** -->
384<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
385<!-- *********************************************************************** -->
386
387<!-- ======================================================================= -->
388<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
389</div>
390
391<div class="doc_text">
392
393<p>LLVM programs are composed of "Module"s, each of which is a
394translation unit of the input programs. Each module consists of
395functions, global variables, and symbol table entries. Modules may be
396combined together with the LLVM linker, which merges function (and
397global variable) definitions, resolves forward declarations, and merges
398symbol table entries. Here is an example of the "hello world" module:</p>
399
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]400<div class="doc_code">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]401<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]402<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
403 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]404
405<i>; External declaration of the puts function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]406<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]407
408<i>; Definition of main function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]409define i32 @main() { <i>; i32()* </i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]410 <i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]411 %cast210 = <a
Chris Lattner6c0955b2007-06-12 17:01:15 +0000[diff] [blame]412 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]413
414 <i>; Call puts function to write out the string to stdout...</i>
415 <a
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]416 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]417 <a
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]418 href="#i_ret">ret</a> i32 0<br>}<br>
419</pre>
420</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]421
422<p>This example is made up of a <a href="#globalvars">global variable</a>
423named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
424function, and a <a href="#functionstructure">function definition</a>
425for "<tt>main</tt>".</p>
426
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]427<p>In general, a module is made up of a list of global values,
428where both functions and global variables are global values. Global values are
429represented by a pointer to a memory location (in this case, a pointer to an
430array of char, and a pointer to a function), and have one of the following <a
431href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]432
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]433</div>
434
435<!-- ======================================================================= -->
436<div class="doc_subsection">
437 <a name="linkage">Linkage Types</a>
438</div>
439
440<div class="doc_text">
441
442<p>
443All Global Variables and Functions have one of the following types of linkage:
444</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]445
446<dl>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]447
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]448 <dt><tt><b><a name="linkage_internal">internal</a></b></tt> </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]449
450 <dd>Global values with internal linkage are only directly accessible by
451 objects in the current module. In particular, linking code into a module with
452 an internal global value may cause the internal to be renamed as necessary to
453 avoid collisions. Because the symbol is internal to the module, all
454 references can be updated. This corresponds to the notion of the
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]455 '<tt>static</tt>' keyword in C.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]456 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]457
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]458 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]459
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]460 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
461 the same name when linkage occurs. This is typically used to implement
462 inline functions, templates, or other code which must be generated in each
463 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
464 allowed to be discarded.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]465 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]466
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]467 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]468
469 <dd>"<tt>weak</tt>" linkage is exactly the same as <tt>linkonce</tt> linkage,
470 except that unreferenced <tt>weak</tt> globals may not be discarded. This is
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]471 used for globals that may be emitted in multiple translation units, but that
472 are not guaranteed to be emitted into every translation unit that uses them.
473 One example of this are common globals in C, such as "<tt>int X;</tt>" at
474 global scope.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]475 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]476
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]477 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]478
479 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
480 pointer to array type. When two global variables with appending linkage are
481 linked together, the two global arrays are appended together. This is the
482 LLVM, typesafe, equivalent of having the system linker append together
483 "sections" with identical names when .o files are linked.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]484 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]485
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]486 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
487 <dd>The semantics of this linkage follow the ELF model: the symbol is weak
488 until linked, if not linked, the symbol becomes null instead of being an
489 undefined reference.
490 </dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]491
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]492 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]493
494 <dd>If none of the above identifiers are used, the global is externally
495 visible, meaning that it participates in linkage and can be used to resolve
496 external symbol references.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]497 </dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]498</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]499
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]500 <p>
501 The next two types of linkage are targeted for Microsoft Windows platform
502 only. They are designed to support importing (exporting) symbols from (to)
503 DLLs.
504 </p>
505
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]506 <dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]507 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
508
509 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
510 or variable via a global pointer to a pointer that is set up by the DLL
511 exporting the symbol. On Microsoft Windows targets, the pointer name is
512 formed by combining <code>_imp__</code> and the function or variable name.
513 </dd>
514
515 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
516
517 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
518 pointer to a pointer in a DLL, so that it can be referenced with the
519 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
520 name is formed by combining <code>_imp__</code> and the function or variable
521 name.
522 </dd>
523
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]524</dl>
525
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]526<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]527variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
528variable and was linked with this one, one of the two would be renamed,
529preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
530external (i.e., lacking any linkage declarations), they are accessible
Reid Spencerac8d2762007-01-05 00:59:10 +0000[diff] [blame]531outside of the current module.</p>
532<p>It is illegal for a function <i>declaration</i>
533to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]534or <tt>extern_weak</tt>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]535<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
536linkages.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]537</div>
538
539<!-- ======================================================================= -->
540<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]541 <a name="callingconv">Calling Conventions</a>
542</div>
543
544<div class="doc_text">
545
546<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
547and <a href="#i_invoke">invokes</a> can all have an optional calling convention
548specified for the call. The calling convention of any pair of dynamic
549caller/callee must match, or the behavior of the program is undefined. The
550following calling conventions are supported by LLVM, and more may be added in
551the future:</p>
552
553<dl>
554 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
555
556 <dd>This calling convention (the default if no other calling convention is
557 specified) matches the target C calling conventions. This calling convention
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]558 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencerc28d2bc2006-12-31 21:30:18 +0000[diff] [blame]559 prototype and implemented declaration of the function (as does normal C).
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]560 </dd>
561
562 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
563
564 <dd>This calling convention attempts to make calls as fast as possible
565 (e.g. by passing things in registers). This calling convention allows the
566 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattner8cdc5bc2005-05-06 23:08:23 +0000[diff] [blame]567 without having to conform to an externally specified ABI. Implementations of
568 this convention should allow arbitrary tail call optimization to be supported.
569 This calling convention does not support varargs and requires the prototype of
570 all callees to exactly match the prototype of the function definition.
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]571 </dd>
572
573 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
574
575 <dd>This calling convention attempts to make code in the caller as efficient
576 as possible under the assumption that the call is not commonly executed. As
577 such, these calls often preserve all registers so that the call does not break
578 any live ranges in the caller side. This calling convention does not support
579 varargs and requires the prototype of all callees to exactly match the
580 prototype of the function definition.
581 </dd>
582
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]583 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]584
585 <dd>Any calling convention may be specified by number, allowing
586 target-specific calling conventions to be used. Target specific calling
587 conventions start at 64.
588 </dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]589</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]590
591<p>More calling conventions can be added/defined on an as-needed basis, to
592support pascal conventions or any other well-known target-independent
593convention.</p>
594
595</div>
596
597<!-- ======================================================================= -->
598<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]599 <a name="visibility">Visibility Styles</a>
600</div>
601
602<div class="doc_text">
603
604<p>
605All Global Variables and Functions have one of the following visibility styles:
606</p>
607
608<dl>
609 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
610
611 <dd>On ELF, default visibility means that the declaration is visible to other
612 modules and, in shared libraries, means that the declared entity may be
613 overridden. On Darwin, default visibility means that the declaration is
614 visible to other modules. Default visibility corresponds to "external
615 linkage" in the language.
616 </dd>
617
618 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
619
620 <dd>Two declarations of an object with hidden visibility refer to the same
621 object if they are in the same shared object. Usually, hidden visibility
622 indicates that the symbol will not be placed into the dynamic symbol table,
623 so no other module (executable or shared library) can reference it
624 directly.
625 </dd>
626
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]627 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
628
629 <dd>On ELF, protected visibility indicates that the symbol will be placed in
630 the dynamic symbol table, but that references within the defining module will
631 bind to the local symbol. That is, the symbol cannot be overridden by another
632 module.
633 </dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]634</dl>
635
636</div>
637
638<!-- ======================================================================= -->
639<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]640 <a name="globalvars">Global Variables</a>
641</div>
642
643<div class="doc_text">
644
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]645<p>Global variables define regions of memory allocated at compilation time
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]646instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]647an explicit section to be placed in, and may have an optional explicit alignment
648specified. A variable may be defined as "thread_local", which means that it
649will not be shared by threads (each thread will have a separated copy of the
650variable). A variable may be defined as a global "constant," which indicates
651that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]652optimization, allowing the global data to be placed in the read-only section of
653an executable, etc). Note that variables that need runtime initialization
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]654cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]655
656<p>
657LLVM explicitly allows <em>declarations</em> of global variables to be marked
658constant, even if the final definition of the global is not. This capability
659can be used to enable slightly better optimization of the program, but requires
660the language definition to guarantee that optimizations based on the
661'constantness' are valid for the translation units that do not include the
662definition.
663</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]664
665<p>As SSA values, global variables define pointer values that are in
666scope (i.e. they dominate) all basic blocks in the program. Global
667variables always define a pointer to their "content" type because they
668describe a region of memory, and all memory objects in LLVM are
669accessed through pointers.</p>
670
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]671<p>A global variable may be declared to reside in a target-specifc numbered
672address space. For targets that support them, address spaces may affect how
673optimizations are performed and/or what target instructions are used to access
Christopher Lambd49e18d2007-12-12 08:44:39 +0000[diff] [blame]674the variable. The default address space is zero. The address space qualifier
675must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]676
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]677<p>LLVM allows an explicit section to be specified for globals. If the target
678supports it, it will emit globals to the section specified.</p>
679
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]680<p>An explicit alignment may be specified for a global. If not present, or if
681the alignment is set to zero, the alignment of the global is set by the target
682to whatever it feels convenient. If an explicit alignment is specified, the
683global is forced to have at least that much alignment. All alignments must be
684a power of 2.</p>
685
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]686<p>For example, the following defines a global in a numbered address space with
687an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]688
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]689<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]690<pre>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]691@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]692</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]693</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]694
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]695</div>
696
697
698<!-- ======================================================================= -->
699<div class="doc_subsection">
700 <a name="functionstructure">Functions</a>
701</div>
702
703<div class="doc_text">
704
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]705<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
706an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]707<a href="#visibility">visibility style</a>, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]708<a href="#callingconv">calling convention</a>, a return type, an optional
709<a href="#paramattrs">parameter attribute</a> for the return type, a function
710name, a (possibly empty) argument list (each with optional
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]711<a href="#paramattrs">parameter attributes</a>), an optional section, an
Gordon Henriksene754abe2007-12-10 03:30:21 +0000[diff] [blame]712optional alignment, an optional <a href="#gc">garbage collector name</a>, an
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]713opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]714
715LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
716optional <a href="#linkage">linkage type</a>, an optional
717<a href="#visibility">visibility style</a>, an optional
718<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]719<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]720name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksene754abe2007-12-10 03:30:21 +0000[diff] [blame]721<a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]722
723<p>A function definition contains a list of basic blocks, forming the CFG for
724the function. Each basic block may optionally start with a label (giving the
725basic block a symbol table entry), contains a list of instructions, and ends
726with a <a href="#terminators">terminator</a> instruction (such as a branch or
727function return).</p>
728
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]729<p>The first basic block in a function is special in two ways: it is immediately
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]730executed on entrance to the function, and it is not allowed to have predecessor
731basic blocks (i.e. there can not be any branches to the entry block of a
732function). Because the block can have no predecessors, it also cannot have any
733<a href="#i_phi">PHI nodes</a>.</p>
734
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]735<p>LLVM allows an explicit section to be specified for functions. If the target
736supports it, it will emit functions to the section specified.</p>
737
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]738<p>An explicit alignment may be specified for a function. If not present, or if
739the alignment is set to zero, the alignment of the function is set by the target
740to whatever it feels convenient. If an explicit alignment is specified, the
741function is forced to have at least that much alignment. All alignments must be
742a power of 2.</p>
743
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]744</div>
745
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]746
747<!-- ======================================================================= -->
748<div class="doc_subsection">
749 <a name="aliasstructure">Aliases</a>
750</div>
751<div class="doc_text">
752 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikova80e1182007-04-28 13:45:00 +0000[diff] [blame]753 function or global variable or bitcast of global value). Aliases may have an
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]754 optional <a href="#linkage">linkage type</a>, and an
755 optional <a href="#visibility">visibility style</a>.</p>
756
757 <h5>Syntax:</h5>
758
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]759<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]760<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]761@&lt;Name&gt; = [Linkage] [Visibility] alias &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]762</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]763</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]764
765</div>
766
767
768
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]769<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]770<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
771<div class="doc_text">
772 <p>The return type and each parameter of a function type may have a set of
773 <i>parameter attributes</i> associated with them. Parameter attributes are
774 used to communicate additional information about the result or parameters of
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]775 a function. Parameter attributes are considered to be part of the function,
776 not of the function type, so functions with different parameter attributes
777 can have the same function type.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]778
Reid Spencer950e9f82007-01-15 18:27:39 +0000[diff] [blame]779 <p>Parameter attributes are simple keywords that follow the type specified. If
780 multiple parameter attributes are needed, they are space separated. For
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]781 example:</p>
782
783<div class="doc_code">
784<pre>
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]785declare i32 @printf(i8* noalias , ...) nounwind
786declare i32 @atoi(i8*) nounwind readonly
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]787</pre>
788</div>
789
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]790 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
791 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]792
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]793 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]794 <dl>
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]795 <dt><tt>zeroext</tt></dt>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]796 <dd>This indicates that the parameter should be zero extended just before
797 a call to this function.</dd>
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]798 <dt><tt>signext</tt></dt>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]799 <dd>This indicates that the parameter should be sign extended just before
800 a call to this function.</dd>
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]801 <dt><tt>inreg</tt></dt>
802 <dd>This indicates that the parameter should be placed in register (if
Anton Korobeynikov66a8c8c2007-01-28 15:27:21 +0000[diff] [blame]803 possible) during assembling function call. Support for this attribute is
804 target-specific</dd>
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]805 <dt><tt>sret</tt></dt>
Anton Korobeynikov66a8c8c2007-01-28 15:27:21 +0000[diff] [blame]806 <dd>This indicates that the parameter specifies the address of a structure
Reid Spencer67606122007-03-22 02:02:11 +0000[diff] [blame]807 that is the return value of the function in the source program.</dd>
Zhou Shengfebca342007-06-05 05:28:26 +0000[diff] [blame]808 <dt><tt>noalias</tt></dt>
809 <dd>This indicates that the parameter not alias any other object or any
810 other "noalias" objects during the function call.
Reid Spencer2dc52012007-03-22 02:18:56 +0000[diff] [blame]811 <dt><tt>noreturn</tt></dt>
812 <dd>This function attribute indicates that the function never returns. This
813 indicates to LLVM that every call to this function should be treated as if
814 an <tt>unreachable</tt> instruction immediately followed the call.</dd>
Reid Spencer67606122007-03-22 02:02:11 +0000[diff] [blame]815 <dt><tt>nounwind</tt></dt>
816 <dd>This function attribute indicates that the function type does not use
817 the unwind instruction and does not allow stack unwinding to propagate
818 through it.</dd>
Duncan Sands50f19f52007-07-27 19:57:41 +0000[diff] [blame]819 <dt><tt>nest</tt></dt>
820 <dd>This indicates that the parameter can be excised using the
821 <a href="#int_trampoline">trampoline intrinsics</a>.</dd>
Duncan Sandsed4a2f12007-11-22 20:23:04 +0000[diff] [blame]822 <dt><tt>readonly</tt></dt>
Duncan Sandsf04d5842007-11-14 21:14:02 +0000[diff] [blame]823 <dd>This function attribute indicates that the function has no side-effects
Duncan Sandsed4a2f12007-11-22 20:23:04 +0000[diff] [blame]824 except for producing a return value or throwing an exception. The value
825 returned must only depend on the function arguments and/or global variables.
826 It may use values obtained by dereferencing pointers.</dd>
827 <dt><tt>readnone</tt></dt>
828 <dd>A <tt>readnone</tt> function has the same restrictions as a <tt>readonly</tt>
Duncan Sandsf04d5842007-11-14 21:14:02 +0000[diff] [blame]829 function, but in addition it is not allowed to dereference any pointer arguments
830 or global variables.
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]831 </dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]832
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]833</div>
834
835<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]836<div class="doc_subsection">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]837 <a name="gc">Garbage Collector Names</a>
838</div>
839
840<div class="doc_text">
841<p>Each function may specify a garbage collector name, which is simply a
842string.</p>
843
844<div class="doc_code"><pre
845>define void @f() gc "name" { ...</pre></div>
846
847<p>The compiler declares the supported values of <i>name</i>. Specifying a
848collector which will cause the compiler to alter its output in order to support
849the named garbage collection algorithm.</p>
850</div>
851
852<!-- ======================================================================= -->
853<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]854 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]855</div>
856
857<div class="doc_text">
858<p>
859Modules may contain "module-level inline asm" blocks, which corresponds to the
860GCC "file scope inline asm" blocks. These blocks are internally concatenated by
861LLVM and treated as a single unit, but may be separated in the .ll file if
862desired. The syntax is very simple:
863</p>
864
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]865<div class="doc_code">
866<pre>
867module asm "inline asm code goes here"
868module asm "more can go here"
869</pre>
870</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]871
872<p>The strings can contain any character by escaping non-printable characters.
873 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
874 for the number.
875</p>
876
877<p>
878 The inline asm code is simply printed to the machine code .s file when
879 assembly code is generated.
880</p>
881</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]882
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]883<!-- ======================================================================= -->
884<div class="doc_subsection">
885 <a name="datalayout">Data Layout</a>
886</div>
887
888<div class="doc_text">
889<p>A module may specify a target specific data layout string that specifies how
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]890data is to be laid out in memory. The syntax for the data layout is simply:</p>
891<pre> target datalayout = "<i>layout specification</i>"</pre>
892<p>The <i>layout specification</i> consists of a list of specifications
893separated by the minus sign character ('-'). Each specification starts with a
894letter and may include other information after the letter to define some
895aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]896<dl>
897 <dt><tt>E</tt></dt>
898 <dd>Specifies that the target lays out data in big-endian form. That is, the
899 bits with the most significance have the lowest address location.</dd>
900 <dt><tt>e</tt></dt>
901 <dd>Specifies that hte target lays out data in little-endian form. That is,
902 the bits with the least significance have the lowest address location.</dd>
903 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
904 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
905 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
906 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
907 too.</dd>
908 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
909 <dd>This specifies the alignment for an integer type of a given bit
910 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
911 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
912 <dd>This specifies the alignment for a vector type of a given bit
913 <i>size</i>.</dd>
914 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
915 <dd>This specifies the alignment for a floating point type of a given bit
916 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
917 (double).</dd>
918 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
919 <dd>This specifies the alignment for an aggregate type of a given bit
920 <i>size</i>.</dd>
921</dl>
922<p>When constructing the data layout for a given target, LLVM starts with a
923default set of specifications which are then (possibly) overriden by the
924specifications in the <tt>datalayout</tt> keyword. The default specifications
925are given in this list:</p>
926<ul>
927 <li><tt>E</tt> - big endian</li>
928 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
929 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
930 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
931 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
932 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
933 <li><tt>i64:32:64</tt> - i64 has abi alignment of 32-bits but preferred
934 alignment of 64-bits</li>
935 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
936 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
937 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
938 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
939 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
940</ul>
941<p>When llvm is determining the alignment for a given type, it uses the
942following rules:
943<ol>
944 <li>If the type sought is an exact match for one of the specifications, that
945 specification is used.</li>
946 <li>If no match is found, and the type sought is an integer type, then the
947 smallest integer type that is larger than the bitwidth of the sought type is
948 used. If none of the specifications are larger than the bitwidth then the the
949 largest integer type is used. For example, given the default specifications
950 above, the i7 type will use the alignment of i8 (next largest) while both
951 i65 and i256 will use the alignment of i64 (largest specified).</li>
952 <li>If no match is found, and the type sought is a vector type, then the
953 largest vector type that is smaller than the sought vector type will be used
954 as a fall back. This happens because <128 x double> can be implemented in
955 terms of 64 <2 x double>, for example.</li>
956</ol>
957</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]958
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]959<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]960<div class="doc_section"> <a name="typesystem">Type System</a> </div>
961<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]962
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]963<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]964
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]965<p>The LLVM type system is one of the most important features of the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]966intermediate representation. Being typed enables a number of
967optimizations to be performed on the IR directly, without having to do
968extra analyses on the side before the transformation. A strong type
969system makes it easier to read the generated code and enables novel
970analyses and transformations that are not feasible to perform on normal
971three address code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]972
973</div>
974
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]975<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]976<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]977<div class="doc_text">
John Criswell4457dc92004-04-09 16:48:45 +0000[diff] [blame]978<p>The primitive types are the fundamental building blocks of the LLVM
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]979system. The current set of primitive types is as follows:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]980
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]981<table class="layout">
982 <tr class="layout">
983 <td class="left">
984 <table>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]985 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]986 <tr><th>Type</th><th>Description</th></tr>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]987 <tr><td><tt><a name="t_void">void</a></tt></td><td>No value</td></tr>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]988 <tr><td><tt>label</tt></td><td>Branch destination</td></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]989 </tbody>
990 </table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]991 </td>
992 <td class="right">
993 <table>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]994 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]995 <tr><th>Type</th><th>Description</th></tr>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]996 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]997 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]998 </tbody>
999 </table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1000 </td>
1001 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1002</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1003</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1004
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1005<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1006<div class="doc_subsubsection"> <a name="t_classifications">Type
1007Classifications</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1008<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1009<p>These different primitive types fall into a few useful
1010classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1011
1012<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1013 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1014 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1015 <tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1016 <td><a name="t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1017 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1018 </tr>
1019 <tr>
1020 <td><a name="t_floating">floating point</a></td>
1021 <td><tt>float, double</tt></td>
1022 </tr>
1023 <tr>
1024 <td><a name="t_firstclass">first class</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1025 <td><tt>i1, ..., float, double, <br/>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1026 <a href="#t_pointer">pointer</a>,<a href="#t_vector">vector</a></tt>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1027 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1028 </tr>
1029 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1030</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1031
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1032<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1033most important. Values of these types are the only ones which can be
1034produced by instructions, passed as arguments, or used as operands to
1035instructions. This means that all structures and arrays must be
1036manipulated either by pointer or by component.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1037</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1038
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1039<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1040<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1041
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1042<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1043
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1044<p>The real power in LLVM comes from the derived types in the system.
1045This is what allows a programmer to represent arrays, functions,
1046pointers, and other useful types. Note that these derived types may be
1047recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1048
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1049</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1050
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1051<!-- _______________________________________________________________________ -->
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1052<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1053
1054<div class="doc_text">
1055
1056<h5>Overview:</h5>
1057<p>The integer type is a very simple derived type that simply specifies an
1058arbitrary bit width for the integer type desired. Any bit width from 1 bit to
10592^23-1 (about 8 million) can be specified.</p>
1060
1061<h5>Syntax:</h5>
1062
1063<pre>
1064 iN
1065</pre>
1066
1067<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1068value.</p>
1069
1070<h5>Examples:</h5>
1071<table class="layout">
1072 <tr class="layout">
1073 <td class="left">
1074 <tt>i1</tt><br/>
1075 <tt>i4</tt><br/>
1076 <tt>i8</tt><br/>
1077 <tt>i16</tt><br/>
1078 <tt>i32</tt><br/>
1079 <tt>i42</tt><br/>
1080 <tt>i64</tt><br/>
1081 <tt>i1942652</tt><br/>
1082 </td>
1083 <td class="left">
1084 A boolean integer of 1 bit<br/>
1085 A nibble sized integer of 4 bits.<br/>
1086 A byte sized integer of 8 bits.<br/>
1087 A half word sized integer of 16 bits.<br/>
1088 A word sized integer of 32 bits.<br/>
1089 An integer whose bit width is the answer. <br/>
1090 A double word sized integer of 64 bits.<br/>
1091 A really big integer of over 1 million bits.<br/>
1092 </td>
1093 </tr>
1094</table>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1095</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1096
1097<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1098<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1099
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1100<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1101
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1102<h5>Overview:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1103
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1104<p>The array type is a very simple derived type that arranges elements
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1105sequentially in memory. The array type requires a size (number of
1106elements) and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1107
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1108<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1109
1110<pre>
1111 [&lt;# elements&gt; x &lt;elementtype&gt;]
1112</pre>
1113
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1114<p>The number of elements is a constant integer value; elementtype may
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1115be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1116
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1117<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1118<table class="layout">
1119 <tr class="layout">
1120 <td class="left">
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1121 <tt>[40 x i32 ]</tt><br/>
1122 <tt>[41 x i32 ]</tt><br/>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1123 <tt>[40 x i8]</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1124 </td>
1125 <td class="left">
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1126 Array of 40 32-bit integer values.<br/>
1127 Array of 41 32-bit integer values.<br/>
1128 Array of 40 8-bit integer values.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1129 </td>
1130 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1131</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1132<p>Here are some examples of multidimensional arrays:</p>
1133<table class="layout">
1134 <tr class="layout">
1135 <td class="left">
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1136 <tt>[3 x [4 x i32]]</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1137 <tt>[12 x [10 x float]]</tt><br/>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1138 <tt>[2 x [3 x [4 x i16]]]</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1139 </td>
1140 <td class="left">
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1141 3x4 array of 32-bit integer values.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1142 12x10 array of single precision floating point values.<br/>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1143 2x3x4 array of 16-bit integer values.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1144 </td>
1145 </tr>
1146</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1147
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1148<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1149length array. Normally, accesses past the end of an array are undefined in
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1150LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1151As a special case, however, zero length arrays are recognized to be variable
1152length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1153type "{ i32, [0 x float]}", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1154
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1155</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1156
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1157<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1158<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1159<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1160<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1161<p>The function type can be thought of as a function signature. It
1162consists of a return type and a list of formal parameter types.
John Criswell009900b2003-11-25 21:45:46 +0000[diff] [blame]1163Function types are usually used to build virtual function tables
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1164(which are structures of pointers to functions), for indirect function
1165calls, and when defining a function.</p>
John Criswell009900b2003-11-25 21:45:46 +0000[diff] [blame]1166<p>
1167The return type of a function type cannot be an aggregate type.
1168</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1169<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1170<pre> &lt;returntype&gt; (&lt;parameter list&gt;)<br></pre>
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1171<p>...where '<tt>&lt;parameter list&gt;</tt>' is a comma-separated list of type
Misha Brukmanc24b7582004-08-12 20:16:08 +0000[diff] [blame]1172specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1173which indicates that the function takes a variable number of arguments.
1174Variable argument functions can access their arguments with the <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1175 href="#int_varargs">variable argument handling intrinsic</a> functions.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1176<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1177<table class="layout">
1178 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1179 <td class="left"><tt>i32 (i32)</tt></td>
1180 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1181 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1182 </tr><tr class="layout">
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]1183 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1184 </tt></td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1185 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1186 an <tt>i16</tt> that should be sign extended and a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1187 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1188 <tt>float</tt>.
1189 </td>
1190 </tr><tr class="layout">
1191 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1192 <td class="left">A vararg function that takes at least one
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1193 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1194 which returns an integer. This is the signature for <tt>printf</tt> in
1195 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1196 </td>
1197 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1198</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1199
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1200</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1201<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1202<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1203<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1204<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1205<p>The structure type is used to represent a collection of data members
1206together in memory. The packing of the field types is defined to match
1207the ABI of the underlying processor. The elements of a structure may
1208be any type that has a size.</p>
1209<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1210and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1211field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1212instruction.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1213<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1214<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1215<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1216<table class="layout">
1217 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1218 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1219 <td class="left">A triple of three <tt>i32</tt> values</td>
1220 </tr><tr class="layout">
1221 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1222 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1223 second element is a <a href="#t_pointer">pointer</a> to a
1224 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1225 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1226 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1227</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1228</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1229
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1230<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1231<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1232</div>
1233<div class="doc_text">
1234<h5>Overview:</h5>
1235<p>The packed structure type is used to represent a collection of data members
1236together in memory. There is no padding between fields. Further, the alignment
1237of a packed structure is 1 byte. The elements of a packed structure may
1238be any type that has a size.</p>
1239<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1240and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1241field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1242instruction.</p>
1243<h5>Syntax:</h5>
1244<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1245<h5>Examples:</h5>
1246<table class="layout">
1247 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1248 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1249 <td class="left">A triple of three <tt>i32</tt> values</td>
1250 </tr><tr class="layout">
1251 <td class="left"><tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}&nbsp;&gt;</tt></td>
1252 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1253 second element is a <a href="#t_pointer">pointer</a> to a
1254 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1255 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1256 </tr>
1257</table>
1258</div>
1259
1260<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1261<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1262<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1263<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1264<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]1265reference to another object, which must live in memory. Pointer types may have
1266an optional address space attribute defining the target-specific numbered
1267address space where the pointed-to object resides. The default address space is
1268zero.</p>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1269<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1270<pre> &lt;type&gt; *<br></pre>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1271<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1272<table class="layout">
1273 <tr class="layout">
1274 <td class="left">
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1275 <tt>[4x i32]*</tt><br/>
1276 <tt>i32 (i32 *) *</tt><br/>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]1277 <tt>i32 addrspace(5)*</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1278 </td>
1279 <td class="left">
1280 A <a href="#t_pointer">pointer</a> to <a href="#t_array">array</a> of
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1281 four <tt>i32</tt> values<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1282 A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1283 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
1284 <tt>i32</tt>.<br/>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]1285 A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value that resides
1286 in address space 5.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1287 </td>
1288 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1289</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1290</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1291
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1292<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1293<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1294<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1295
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1296<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1297
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1298<p>A vector type is a simple derived type that represents a vector
1299of elements. Vector types are used when multiple primitive data
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1300are operated in parallel using a single instruction (SIMD).
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1301A vector type requires a size (number of
Chris Lattnerb8d172f2005-11-10 01:44:22 +0000[diff] [blame]1302elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1303of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1304considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1305
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1306<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1307
1308<pre>
1309 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1310</pre>
1311
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1312<p>The number of elements is a constant integer value; elementtype may
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1313be any integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1314
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1315<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1316
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1317<table class="layout">
1318 <tr class="layout">
1319 <td class="left">
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1320 <tt>&lt;4 x i32&gt;</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1321 <tt>&lt;8 x float&gt;</tt><br/>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1322 <tt>&lt;2 x i64&gt;</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1323 </td>
1324 <td class="left">
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1325 Vector of 4 32-bit integer values.<br/>
1326 Vector of 8 floating-point values.<br/>
1327 Vector of 2 64-bit integer values.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1328 </td>
1329 </tr>
1330</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1331</div>
1332
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1333<!-- _______________________________________________________________________ -->
1334<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1335<div class="doc_text">
1336
1337<h5>Overview:</h5>
1338
1339<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksen8ac04ff2007-10-14 00:34:53 +0000[diff] [blame]1340corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1341In LLVM, opaque types can eventually be resolved to any type (not just a
1342structure type).</p>
1343
1344<h5>Syntax:</h5>
1345
1346<pre>
1347 opaque
1348</pre>
1349
1350<h5>Examples:</h5>
1351
1352<table class="layout">
1353 <tr class="layout">
1354 <td class="left">
1355 <tt>opaque</tt>
1356 </td>
1357 <td class="left">
1358 An opaque type.<br/>
1359 </td>
1360 </tr>
1361</table>
1362</div>
1363
1364
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1365<!-- *********************************************************************** -->
1366<div class="doc_section"> <a name="constants">Constants</a> </div>
1367<!-- *********************************************************************** -->
1368
1369<div class="doc_text">
1370
1371<p>LLVM has several different basic types of constants. This section describes
1372them all and their syntax.</p>
1373
1374</div>
1375
1376<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1377<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1378
1379<div class="doc_text">
1380
1381<dl>
1382 <dt><b>Boolean constants</b></dt>
1383
1384 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1385 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1386 </dd>
1387
1388 <dt><b>Integer constants</b></dt>
1389
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1390 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1391 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1392 integer types.
1393 </dd>
1394
1395 <dt><b>Floating point constants</b></dt>
1396
1397 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1398 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1399 notation (see below). Floating point constants must have a <a
1400 href="#t_floating">floating point</a> type. </dd>
1401
1402 <dt><b>Null pointer constants</b></dt>
1403
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1404 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1405 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1406
1407</dl>
1408
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1409<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1410of floating point constants. For example, the form '<tt>double
14110x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
14124.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1413(and the only time that they are generated by the disassembler) is when a
1414floating point constant must be emitted but it cannot be represented as a
1415decimal floating point number. For example, NaN's, infinities, and other
1416special values are represented in their IEEE hexadecimal format so that
1417assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1418
1419</div>
1420
1421<!-- ======================================================================= -->
1422<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1423</div>
1424
1425<div class="doc_text">
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]1426<p>Aggregate constants arise from aggregation of simple constants
1427and smaller aggregate constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1428
1429<dl>
1430 <dt><b>Structure constants</b></dt>
1431
1432 <dd>Structure constants are represented with notation similar to structure
1433 type definitions (a comma separated list of elements, surrounded by braces
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1434 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* %G }</tt>",
Chris Lattner3e63a9d2007-07-13 20:01:46 +0000[diff] [blame]1435 where "<tt>%G</tt>" is declared as "<tt>@G = external global i32</tt>". Structure constants
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]1436 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1437 types of elements must match those specified by the type.
1438 </dd>
1439
1440 <dt><b>Array constants</b></dt>
1441
1442 <dd>Array constants are represented with notation similar to array type
1443 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1444 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1445 constants must have <a href="#t_array">array type</a>, and the number and
1446 types of elements must match those specified by the type.
1447 </dd>
1448
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1449 <dt><b>Vector constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1450
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1451 <dd>Vector constants are represented with notation similar to vector type
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1452 definitions (a comma separated list of elements, surrounded by
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1453 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32 42,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1454 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1455 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1456 match those specified by the type.
1457 </dd>
1458
1459 <dt><b>Zero initialization</b></dt>
1460
1461 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1462 value to zero of <em>any</em> type, including scalar and aggregate types.
1463 This is often used to avoid having to print large zero initializers (e.g. for
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1464 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1465 initializers.
1466 </dd>
1467</dl>
1468
1469</div>
1470
1471<!-- ======================================================================= -->
1472<div class="doc_subsection">
1473 <a name="globalconstants">Global Variable and Function Addresses</a>
1474</div>
1475
1476<div class="doc_text">
1477
1478<p>The addresses of <a href="#globalvars">global variables</a> and <a
1479href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1480constants. These constants are explicitly referenced when the <a
1481href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1482href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1483file:</p>
1484
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1485<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1486<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]1487@X = global i32 17
1488@Y = global i32 42
1489@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1490</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1491</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1492
1493</div>
1494
1495<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1496<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1497<div class="doc_text">
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1498 <p>The string '<tt>undef</tt>' is recognized as a type-less constant that has
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1499 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1500 a constant is permitted.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1501
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1502 <p>Undefined values indicate to the compiler that the program is well defined
1503 no matter what value is used, giving the compiler more freedom to optimize.
1504 </p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1505</div>
1506
1507<!-- ======================================================================= -->
1508<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1509</div>
1510
1511<div class="doc_text">
1512
1513<p>Constant expressions are used to allow expressions involving other constants
1514to be used as constants. Constant expressions may be of any <a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1515href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1516that does not have side effects (e.g. load and call are not supported). The
1517following is the syntax for constant expressions:</p>
1518
1519<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1520 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1521 <dd>Truncate a constant to another type. The bit size of CST must be larger
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1522 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1523
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1524 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1525 <dd>Zero extend a constant to another type. The bit size of CST must be
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1526 smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1527
1528 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1529 <dd>Sign extend a constant to another type. The bit size of CST must be
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1530 smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1531
1532 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1533 <dd>Truncate a floating point constant to another floating point type. The
1534 size of CST must be larger than the size of TYPE. Both types must be
1535 floating point.</dd>
1536
1537 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1538 <dd>Floating point extend a constant to another type. The size of CST must be
1539 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1540
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]1541 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1542 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1543 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1544 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1545 of the same number of elements. If the value won't fit in the integer type,
1546 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1547
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1548 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1549 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1550 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1551 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1552 of the same number of elements. If the value won't fit in the integer type,
1553 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1554
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1555 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1556 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1557 constant. TYPE must be a scalar or vector floating point type. CST must be of
1558 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1559 of the same number of elements. If the value won't fit in the floating point
1560 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1561
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1562 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1563 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1564 constant. TYPE must be a scalar or vector floating point type. CST must be of
1565 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1566 of the same number of elements. If the value won't fit in the floating point
1567 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1568
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1569 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1570 <dd>Convert a pointer typed constant to the corresponding integer constant
1571 TYPE must be an integer type. CST must be of pointer type. The CST value is
1572 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1573
1574 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1575 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1576 pointer type. CST must be of integer type. The CST value is zero extended,
1577 truncated, or unchanged to make it fit in a pointer size. This one is
1578 <i>really</i> dangerous!</dd>
1579
1580 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1581 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1582 identical (same number of bits). The conversion is done as if the CST value
1583 was stored to memory and read back as TYPE. In other words, no bits change
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1584 with this operator, just the type. This can be used for conversion of
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1585 vector types to any other type, as long as they have the same bit width. For
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1586 pointers it is only valid to cast to another pointer type.
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1587 </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1588
1589 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1590
1591 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1592 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1593 instruction, the index list may have zero or more indexes, which are required
1594 to make sense for the type of "CSTPTR".</dd>
1595
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1596 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1597
1598 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1599 constants.</dd>
1600
1601 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1602 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1603
1604 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1605 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1606
1607 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1608
1609 <dd>Perform the <a href="#i_extractelement">extractelement
1610 operation</a> on constants.
1611
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1612 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1613
1614 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1615 operation</a> on constants.</dd>
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1616
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1617
1618 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1619
1620 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1621 operation</a> on constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1622
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1623 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1624
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1625 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1626 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1627 binary</a> operations. The constraints on operands are the same as those for
1628 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1629 values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1630</dl>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1631</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]1632
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1633<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1634<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1635<!-- *********************************************************************** -->
1636
1637<!-- ======================================================================= -->
1638<div class="doc_subsection">
1639<a name="inlineasm">Inline Assembler Expressions</a>
1640</div>
1641
1642<div class="doc_text">
1643
1644<p>
1645LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1646Module-Level Inline Assembly</a>) through the use of a special value. This
1647value represents the inline assembler as a string (containing the instructions
1648to emit), a list of operand constraints (stored as a string), and a flag that
1649indicates whether or not the inline asm expression has side effects. An example
1650inline assembler expression is:
1651</p>
1652
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1653<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1654<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1655i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1656</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1657</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1658
1659<p>
1660Inline assembler expressions may <b>only</b> be used as the callee operand of
1661a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
1662</p>
1663
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1664<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1665<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1666%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]1667</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1668</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1669
1670<p>
1671Inline asms with side effects not visible in the constraint list must be marked
1672as having side effects. This is done through the use of the
1673'<tt>sideeffect</tt>' keyword, like so:
1674</p>
1675
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1676<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1677<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1678call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1679</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1680</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1681
1682<p>TODO: The format of the asm and constraints string still need to be
1683documented here. Constraints on what can be done (e.g. duplication, moving, etc
1684need to be documented).
1685</p>
1686
1687</div>
1688
1689<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1690<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
1691<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1692
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1693<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1694
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1695<p>The LLVM instruction set consists of several different
1696classifications of instructions: <a href="#terminators">terminator
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1697instructions</a>, <a href="#binaryops">binary instructions</a>,
1698<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1699 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
1700instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1701
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1702</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1703
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1704<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1705<div class="doc_subsection"> <a name="terminators">Terminator
1706Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1707
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1708<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1709
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1710<p>As mentioned <a href="#functionstructure">previously</a>, every
1711basic block in a program ends with a "Terminator" instruction, which
1712indicates which block should be executed after the current block is
1713finished. These terminator instructions typically yield a '<tt>void</tt>'
1714value: they produce control flow, not values (the one exception being
1715the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1716<p>There are six different terminator instructions: the '<a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1717 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
1718instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1719the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
1720 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
1721 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1722
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1723</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1724
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1725<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1726<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
1727Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1728<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1729<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1730<pre> ret &lt;type&gt; &lt;value&gt; <i>; Return a value from a non-void function</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1731 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1732</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1733<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1734<p>The '<tt>ret</tt>' instruction is used to return control flow (and a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1735value) from a function back to the caller.</p>
John Criswell4457dc92004-04-09 16:48:45 +0000[diff] [blame]1736<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1737returns a value and then causes control flow, and one that just causes
1738control flow to occur.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1739<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1740<p>The '<tt>ret</tt>' instruction may return any '<a
1741 href="#t_firstclass">first class</a>' type. Notice that a function is
1742not <a href="#wellformed">well formed</a> if there exists a '<tt>ret</tt>'
1743instruction inside of the function that returns a value that does not
1744match the return type of the function.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1745<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1746<p>When the '<tt>ret</tt>' instruction is executed, control flow
1747returns back to the calling function's context. If the caller is a "<a
John Criswellfa081872004-06-25 15:16:57 +0000[diff] [blame]1748 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1749the instruction after the call. If the caller was an "<a
1750 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1751at the beginning of the "normal" destination block. If the instruction
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1752returns a value, that value shall set the call or invoke instruction's
1753return value.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1754<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1755<pre> ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1756 ret void <i>; Return from a void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1757</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1758</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1759<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1760<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1761<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1762<h5>Syntax:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1763<pre> br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;<br> br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1764</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1765<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1766<p>The '<tt>br</tt>' instruction is used to cause control flow to
1767transfer to a different basic block in the current function. There are
1768two forms of this instruction, corresponding to a conditional branch
1769and an unconditional branch.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1770<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1771<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1772single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1773unconditional form of the '<tt>br</tt>' instruction takes a single
1774'<tt>label</tt>' value as a target.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1775<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1776<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1777argument is evaluated. If the value is <tt>true</tt>, control flows
1778to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
1779control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1780<h5>Example:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1781<pre>Test:<br> %cond = <a href="#i_icmp">icmp</a> eq, i32 %a, %b<br> br i1 %cond, label %IfEqual, label %IfUnequal<br>IfEqual:<br> <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1782 href="#i_ret">ret</a> i32 1<br>IfUnequal:<br> <a href="#i_ret">ret</a> i32 0<br></pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1783</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1784<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1785<div class="doc_subsubsection">
1786 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
1787</div>
1788
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1789<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1790<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1791
1792<pre>
1793 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
1794</pre>
1795
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1796<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1797
1798<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
1799several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1800instruction, allowing a branch to occur to one of many possible
1801destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1802
1803
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1804<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1805
1806<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
1807comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
1808an array of pairs of comparison value constants and '<tt>label</tt>'s. The
1809table is not allowed to contain duplicate constant entries.</p>
1810
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1811<h5>Semantics:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1812
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1813<p>The <tt>switch</tt> instruction specifies a table of values and
1814destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]1815table is searched for the given value. If the value is found, control flow is
1816transfered to the corresponding destination; otherwise, control flow is
1817transfered to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1818
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1819<h5>Implementation:</h5>
1820
1821<p>Depending on properties of the target machine and the particular
1822<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]1823ways. For example, it could be generated as a series of chained conditional
1824branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1825
1826<h5>Example:</h5>
1827
1828<pre>
1829 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1830 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1831 switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1832
1833 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1834 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1835
1836 <i>; Implement a jump table:</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1837 switch i32 %val, label %otherwise [ i32 0, label %onzero
1838 i32 1, label %onone
1839 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1840</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1841</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1842
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1843<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1844<div class="doc_subsubsection">
1845 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
1846</div>
1847
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1848<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1849
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1850<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1851
1852<pre>
1853 &lt;result&gt; = invoke [<a href="#callingconv">cconv</a>] &lt;ptr to function ty&gt; %&lt;function ptr val&gt;(&lt;function args&gt;)
Chris Lattner76b8a332006-05-14 18:23:06 +0000[diff] [blame]1854 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1855</pre>
1856
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]1857<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1858
1859<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
1860function, with the possibility of control flow transfer to either the
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1861'<tt>normal</tt>' label or the
1862'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1863"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
1864"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1865href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
1866continued at the dynamically nearest "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1867
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1868<h5>Arguments:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1869
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1870<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1871
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1872<ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1873 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]1874 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1875 convention</a> the call should use. If none is specified, the call defaults
1876 to using C calling conventions.
1877 </li>
1878 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
1879 function value being invoked. In most cases, this is a direct function
1880 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
1881 an arbitrary pointer to function value.
1882 </li>
1883
1884 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
1885 function to be invoked. </li>
1886
1887 <li>'<tt>function args</tt>': argument list whose types match the function
1888 signature argument types. If the function signature indicates the function
1889 accepts a variable number of arguments, the extra arguments can be
1890 specified. </li>
1891
1892 <li>'<tt>normal label</tt>': the label reached when the called function
1893 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
1894
1895 <li>'<tt>exception label</tt>': the label reached when a callee returns with
1896 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
1897
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1898</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1899
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1900<h5>Semantics:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1901
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1902<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1903href="#i_call">call</a></tt>' instruction in most regards. The primary
1904difference is that it establishes an association with a label, which is used by
1905the runtime library to unwind the stack.</p>
1906
1907<p>This instruction is used in languages with destructors to ensure that proper
1908cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
1909exception. Additionally, this is important for implementation of
1910'<tt>catch</tt>' clauses in high-level languages that support them.</p>
1911
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1912<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1913<pre>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1914 %retval = invoke i32 %Test(i32 15) to label %Continue
1915 unwind label %TestCleanup <i>; {i32}:retval set</i>
1916 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Test(i32 15) to label %Continue
1917 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1918</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1919</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1920
1921
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1922<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1923
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1924<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
1925Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1926
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1927<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1928
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1929<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1930<pre>
1931 unwind
1932</pre>
1933
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1934<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1935
1936<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
1937at the first callee in the dynamic call stack which used an <a
1938href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
1939primarily used to implement exception handling.</p>
1940
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1941<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1942
1943<p>The '<tt>unwind</tt>' intrinsic causes execution of the current function to
1944immediately halt. The dynamic call stack is then searched for the first <a
1945href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
1946execution continues at the "exceptional" destination block specified by the
1947<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
1948dynamic call chain, undefined behavior results.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1949</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1950
1951<!-- _______________________________________________________________________ -->
1952
1953<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
1954Instruction</a> </div>
1955
1956<div class="doc_text">
1957
1958<h5>Syntax:</h5>
1959<pre>
1960 unreachable
1961</pre>
1962
1963<h5>Overview:</h5>
1964
1965<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
1966instruction is used to inform the optimizer that a particular portion of the
1967code is not reachable. This can be used to indicate that the code after a
1968no-return function cannot be reached, and other facts.</p>
1969
1970<h5>Semantics:</h5>
1971
1972<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
1973</div>
1974
1975
1976
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1977<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1978<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1979<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1980<p>Binary operators are used to do most of the computation in a
1981program. They require two operands, execute an operation on them, and
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1982produce a single value. The operands might represent
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1983multiple data, as is the case with the <a href="#t_vector">vector</a> data type.
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1984The result value of a binary operator is not
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1985necessarily the same type as its operands.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1986<p>There are several different binary operators:</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1987</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1988<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1989<div class="doc_subsubsection"> <a name="i_add">'<tt>add</tt>'
1990Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1991<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1992<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1993<pre> &lt;result&gt; = add &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1994</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1995<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1996<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1997<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1998<p>The two arguments to the '<tt>add</tt>' instruction must be either <a
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1999 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a> values.
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2000 This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2001Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2002<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2003<p>The value produced is the integer or floating point sum of the two
2004operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2005<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2006<pre> &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2007</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2008</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2009<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2010<div class="doc_subsubsection"> <a name="i_sub">'<tt>sub</tt>'
2011Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2012<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2013<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2014<pre> &lt;result&gt; = sub &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2015</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2016<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2017<p>The '<tt>sub</tt>' instruction returns the difference of its two
2018operands.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2019<p>Note that the '<tt>sub</tt>' instruction is used to represent the '<tt>neg</tt>'
2020instruction present in most other intermediate representations.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2021<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2022<p>The two arguments to the '<tt>sub</tt>' instruction must be either <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2023 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2024values.
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2025This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2026Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2027<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2028<p>The value produced is the integer or floating point difference of
2029the two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2030<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2031<pre>
2032 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2033 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2034</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2035</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2036<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2037<div class="doc_subsubsection"> <a name="i_mul">'<tt>mul</tt>'
2038Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2039<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2040<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2041<pre> &lt;result&gt; = mul &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2042</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2043<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2044<p>The '<tt>mul</tt>' instruction returns the product of its two
2045operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2046<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2047<p>The two arguments to the '<tt>mul</tt>' instruction must be either <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2048 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2049values.
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2050This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2051Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2052<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2053<p>The value produced is the integer or floating point product of the
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2054two operands.</p>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]2055<p>Because the operands are the same width, the result of an integer
2056multiplication is the same whether the operands should be deemed unsigned or
2057signed.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2058<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2059<pre> &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2060</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2061</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2062<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2063<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2064</a></div>
2065<div class="doc_text">
2066<h5>Syntax:</h5>
2067<pre> &lt;result&gt; = udiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2068</pre>
2069<h5>Overview:</h5>
2070<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2071operands.</p>
2072<h5>Arguments:</h5>
2073<p>The two arguments to the '<tt>udiv</tt>' instruction must be
2074<a href="#t_integer">integer</a> values. Both arguments must have identical
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2075types. This instruction can also take <a href="#t_vector">vector</a> versions
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2076of the values in which case the elements must be integers.</p>
2077<h5>Semantics:</h5>
2078<p>The value produced is the unsigned integer quotient of the two operands. This
2079instruction always performs an unsigned division operation, regardless of
2080whether the arguments are unsigned or not.</p>
2081<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2082<pre> &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2083</pre>
2084</div>
2085<!-- _______________________________________________________________________ -->
2086<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2087</a> </div>
2088<div class="doc_text">
2089<h5>Syntax:</h5>
2090<pre> &lt;result&gt; = sdiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2091</pre>
2092<h5>Overview:</h5>
2093<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2094operands.</p>
2095<h5>Arguments:</h5>
2096<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2097<a href="#t_integer">integer</a> values. Both arguments must have identical
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2098types. This instruction can also take <a href="#t_vector">vector</a> versions
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2099of the values in which case the elements must be integers.</p>
2100<h5>Semantics:</h5>
2101<p>The value produced is the signed integer quotient of the two operands. This
2102instruction always performs a signed division operation, regardless of whether
2103the arguments are signed or not.</p>
2104<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2105<pre> &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2106</pre>
2107</div>
2108<!-- _______________________________________________________________________ -->
2109<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2110Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2111<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2112<h5>Syntax:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2113<pre> &lt;result&gt; = fdiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2114</pre>
2115<h5>Overview:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2116<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2117operands.</p>
2118<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2119<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2120<a href="#t_floating">floating point</a> values. Both arguments must have
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2121identical types. This instruction can also take <a href="#t_vector">vector</a>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2122versions of floating point values.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2123<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2124<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2125<h5>Example:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2126<pre> &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]2127</pre>
2128</div>
2129<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2130<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2131</div>
2132<div class="doc_text">
2133<h5>Syntax:</h5>
2134<pre> &lt;result&gt; = urem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2135</pre>
2136<h5>Overview:</h5>
2137<p>The '<tt>urem</tt>' instruction returns the remainder from the
2138unsigned division of its two arguments.</p>
2139<h5>Arguments:</h5>
2140<p>The two arguments to the '<tt>urem</tt>' instruction must be
2141<a href="#t_integer">integer</a> values. Both arguments must have identical
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2142types. This instruction can also take <a href="#t_vector">vector</a> versions
2143of the values in which case the elements must be integers.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2144<h5>Semantics:</h5>
2145<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
2146This instruction always performs an unsigned division to get the remainder,
2147regardless of whether the arguments are unsigned or not.</p>
2148<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2149<pre> &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2150</pre>
2151
2152</div>
2153<!-- _______________________________________________________________________ -->
2154<div class="doc_subsubsection"> <a name="i_srem">'<tt>srem</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2155Instruction</a> </div>
2156<div class="doc_text">
2157<h5>Syntax:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2158<pre> &lt;result&gt; = srem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2159</pre>
2160<h5>Overview:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2161<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2162signed division of its two operands. This instruction can also take
2163<a href="#t_vector">vector</a> versions of the values in which case
2164the elements must be integers.</p>
2165</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2166<h5>Arguments:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2167<p>The two arguments to the '<tt>srem</tt>' instruction must be
2168<a href="#t_integer">integer</a> values. Both arguments must have identical
2169types.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2170<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2171<p>This instruction returns the <i>remainder</i> of a division (where the result
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2172has the same sign as the dividend, <tt>var1</tt>), not the <i>modulo</i>
2173operator (where the result has the same sign as the divisor, <tt>var2</tt>) of
2174a value. For more information about the difference, see <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2175 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2176Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencer64f5c6c2007-03-24 22:40:44 +0000[diff] [blame]2177please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2178Wikipedia: modulo operation</a>.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2179<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2180<pre> &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2181</pre>
2182
2183</div>
2184<!-- _______________________________________________________________________ -->
2185<div class="doc_subsubsection"> <a name="i_frem">'<tt>frem</tt>'
2186Instruction</a> </div>
2187<div class="doc_text">
2188<h5>Syntax:</h5>
2189<pre> &lt;result&gt; = frem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2190</pre>
2191<h5>Overview:</h5>
2192<p>The '<tt>frem</tt>' instruction returns the remainder from the
2193division of its two operands.</p>
2194<h5>Arguments:</h5>
2195<p>The two arguments to the '<tt>frem</tt>' instruction must be
2196<a href="#t_floating">floating point</a> values. Both arguments must have
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2197identical types. This instruction can also take <a href="#t_vector">vector</a>
2198versions of floating point values.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2199<h5>Semantics:</h5>
2200<p>This instruction returns the <i>remainder</i> of a division.</p>
2201<h5>Example:</h5>
2202<pre> &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]2203</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2204</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]2205
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2206<!-- ======================================================================= -->
2207<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2208Operations</a> </div>
2209<div class="doc_text">
2210<p>Bitwise binary operators are used to do various forms of
2211bit-twiddling in a program. They are generally very efficient
2212instructions and can commonly be strength reduced from other
2213instructions. They require two operands, execute an operation on them,
2214and produce a single value. The resulting value of the bitwise binary
2215operators is always the same type as its first operand.</p>
2216</div>
2217
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2218<!-- _______________________________________________________________________ -->
2219<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2220Instruction</a> </div>
2221<div class="doc_text">
2222<h5>Syntax:</h5>
2223<pre> &lt;result&gt; = shl &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2224</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2225
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2226<h5>Overview:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2227
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2228<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2229the left a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2230
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2231<h5>Arguments:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2232
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2233<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
2234 href="#t_integer">integer</a> type.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2235
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2236<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2237
2238<p>The value produced is <tt>var1</tt> * 2<sup><tt>var2</tt></sup>. If
2239<tt>var2</tt> is (statically or dynamically) equal to or larger than the number
2240of bits in <tt>var1</tt>, the result is undefined.</p>
2241
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2242<h5>Example:</h5><pre>
2243 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2244 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2245 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2246 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2247</pre>
2248</div>
2249<!-- _______________________________________________________________________ -->
2250<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2251Instruction</a> </div>
2252<div class="doc_text">
2253<h5>Syntax:</h5>
2254<pre> &lt;result&gt; = lshr &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2255</pre>
2256
2257<h5>Overview:</h5>
2258<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2259operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2260
2261<h5>Arguments:</h5>
2262<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
2263<a href="#t_integer">integer</a> type.</p>
2264
2265<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2266
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2267<p>This instruction always performs a logical shift right operation. The most
2268significant bits of the result will be filled with zero bits after the
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2269shift. If <tt>var2</tt> is (statically or dynamically) equal to or larger than
2270the number of bits in <tt>var1</tt>, the result is undefined.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2271
2272<h5>Example:</h5>
2273<pre>
2274 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2275 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2276 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2277 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2278 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2279</pre>
2280</div>
2281
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2282<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2283<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2284Instruction</a> </div>
2285<div class="doc_text">
2286
2287<h5>Syntax:</h5>
2288<pre> &lt;result&gt; = ashr &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2289</pre>
2290
2291<h5>Overview:</h5>
2292<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2293operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2294
2295<h5>Arguments:</h5>
2296<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
2297<a href="#t_integer">integer</a> type.</p>
2298
2299<h5>Semantics:</h5>
2300<p>This instruction always performs an arithmetic shift right operation,
2301The most significant bits of the result will be filled with the sign bit
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2302of <tt>var1</tt>. If <tt>var2</tt> is (statically or dynamically) equal to or
2303larger than the number of bits in <tt>var1</tt>, the result is undefined.
2304</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2305
2306<h5>Example:</h5>
2307<pre>
2308 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2309 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2310 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2311 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2312 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2313</pre>
2314</div>
2315
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2316<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2317<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2318Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2319<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2320<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2321<pre> &lt;result&gt; = and &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2322</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2323<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2324<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2325its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2326<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2327<p>The two arguments to the '<tt>and</tt>' instruction must be <a
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]2328 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2329identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2330<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2331<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2332<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2333<div style="align: center">
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2334<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2335 <tbody>
2336 <tr>
2337 <td>In0</td>
2338 <td>In1</td>
2339 <td>Out</td>
2340 </tr>
2341 <tr>
2342 <td>0</td>
2343 <td>0</td>
2344 <td>0</td>
2345 </tr>
2346 <tr>
2347 <td>0</td>
2348 <td>1</td>
2349 <td>0</td>
2350 </tr>
2351 <tr>
2352 <td>1</td>
2353 <td>0</td>
2354 <td>0</td>
2355 </tr>
2356 <tr>
2357 <td>1</td>
2358 <td>1</td>
2359 <td>1</td>
2360 </tr>
2361 </tbody>
2362</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2363</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2364<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2365<pre> &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
2366 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2367 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2368</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2369</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2370<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2371<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2372<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2373<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2374<pre> &lt;result&gt; = or &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2375</pre>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2376<h5>Overview:</h5>
2377<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2378or of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2379<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2380<p>The two arguments to the '<tt>or</tt>' instruction must be <a
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]2381 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2382identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2383<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2384<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2385<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2386<div style="align: center">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2387<table border="1" cellspacing="0" cellpadding="4">
2388 <tbody>
2389 <tr>
2390 <td>In0</td>
2391 <td>In1</td>
2392 <td>Out</td>
2393 </tr>
2394 <tr>
2395 <td>0</td>
2396 <td>0</td>
2397 <td>0</td>
2398 </tr>
2399 <tr>
2400 <td>0</td>
2401 <td>1</td>
2402 <td>1</td>
2403 </tr>
2404 <tr>
2405 <td>1</td>
2406 <td>0</td>
2407 <td>1</td>
2408 </tr>
2409 <tr>
2410 <td>1</td>
2411 <td>1</td>
2412 <td>1</td>
2413 </tr>
2414 </tbody>
2415</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2416</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2417<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2418<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2419 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2420 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2421</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2422</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2423<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2424<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2425Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2426<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2427<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2428<pre> &lt;result&gt; = xor &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2429</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2430<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2431<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2432or of its two operands. The <tt>xor</tt> is used to implement the
2433"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2434<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2435<p>The two arguments to the '<tt>xor</tt>' instruction must be <a
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]2436 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2437identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2438<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2439<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2440<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2441<div style="align: center">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2442<table border="1" cellspacing="0" cellpadding="4">
2443 <tbody>
2444 <tr>
2445 <td>In0</td>
2446 <td>In1</td>
2447 <td>Out</td>
2448 </tr>
2449 <tr>
2450 <td>0</td>
2451 <td>0</td>
2452 <td>0</td>
2453 </tr>
2454 <tr>
2455 <td>0</td>
2456 <td>1</td>
2457 <td>1</td>
2458 </tr>
2459 <tr>
2460 <td>1</td>
2461 <td>0</td>
2462 <td>1</td>
2463 </tr>
2464 <tr>
2465 <td>1</td>
2466 <td>1</td>
2467 <td>0</td>
2468 </tr>
2469 </tbody>
2470</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2471</div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2472<p> </p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2473<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2474<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2475 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2476 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2477 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2478</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2479</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2480
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2481<!-- ======================================================================= -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2482<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2483 <a name="vectorops">Vector Operations</a>
2484</div>
2485
2486<div class="doc_text">
2487
2488<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2489target-independent manner. These instructions cover the element-access and
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2490vector-specific operations needed to process vectors effectively. While LLVM
2491does directly support these vector operations, many sophisticated algorithms
2492will want to use target-specific intrinsics to take full advantage of a specific
2493target.</p>
2494
2495</div>
2496
2497<!-- _______________________________________________________________________ -->
2498<div class="doc_subsubsection">
2499 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
2500</div>
2501
2502<div class="doc_text">
2503
2504<h5>Syntax:</h5>
2505
2506<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2507 &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]2508</pre>
2509
2510<h5>Overview:</h5>
2511
2512<p>
2513The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2514element from a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2515</p>
2516
2517
2518<h5>Arguments:</h5>
2519
2520<p>
2521The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2522value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2523an index indicating the position from which to extract the element.
2524The index may be a variable.</p>
2525
2526<h5>Semantics:</h5>
2527
2528<p>
2529The result is a scalar of the same type as the element type of
2530<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
2531<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
2532results are undefined.
2533</p>
2534
2535<h5>Example:</h5>
2536
2537<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2538 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2539</pre>
2540</div>
2541
2542
2543<!-- _______________________________________________________________________ -->
2544<div class="doc_subsubsection">
2545 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
2546</div>
2547
2548<div class="doc_text">
2549
2550<h5>Syntax:</h5>
2551
2552<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2553 &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]2554</pre>
2555
2556<h5>Overview:</h5>
2557
2558<p>
2559The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2560element into a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2561</p>
2562
2563
2564<h5>Arguments:</h5>
2565
2566<p>
2567The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2568value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2569scalar value whose type must equal the element type of the first
2570operand. The third operand is an index indicating the position at
2571which to insert the value. The index may be a variable.</p>
2572
2573<h5>Semantics:</h5>
2574
2575<p>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2576The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2577element values are those of <tt>val</tt> except at position
2578<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
2579exceeds the length of <tt>val</tt>, the results are undefined.
2580</p>
2581
2582<h5>Example:</h5>
2583
2584<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2585 %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]2586</pre>
2587</div>
2588
2589<!-- _______________________________________________________________________ -->
2590<div class="doc_subsubsection">
2591 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
2592</div>
2593
2594<div class="doc_text">
2595
2596<h5>Syntax:</h5>
2597
2598<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2599 &lt;result&gt; = shufflevector &lt;n x &lt;ty&gt;&gt; &lt;v1&gt;, &lt;n x &lt;ty&gt;&gt; &lt;v2&gt;, &lt;n x i32&gt; &lt;mask&gt; <i>; yields &lt;n x &lt;ty&gt;&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2600</pre>
2601
2602<h5>Overview:</h5>
2603
2604<p>
2605The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
2606from two input vectors, returning a vector of the same type.
2607</p>
2608
2609<h5>Arguments:</h5>
2610
2611<p>
2612The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
2613with types that match each other and types that match the result of the
2614instruction. The third argument is a shuffle mask, which has the same number
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2615of elements as the other vector type, but whose element type is always 'i32'.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2616</p>
2617
2618<p>
2619The shuffle mask operand is required to be a constant vector with either
2620constant integer or undef values.
2621</p>
2622
2623<h5>Semantics:</h5>
2624
2625<p>
2626The elements of the two input vectors are numbered from left to right across
2627both of the vectors. The shuffle mask operand specifies, for each element of
2628the result vector, which element of the two input registers the result element
2629gets. The element selector may be undef (meaning "don't care") and the second
2630operand may be undef if performing a shuffle from only one vector.
2631</p>
2632
2633<h5>Example:</h5>
2634
2635<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2636 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2637 &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]2638 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
2639 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i> - Identity shuffle.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2640</pre>
2641</div>
2642
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]2643
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2644<!-- ======================================================================= -->
2645<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]2646 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2647</div>
2648
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2649<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2650
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2651<p>A key design point of an SSA-based representation is how it
2652represents memory. In LLVM, no memory locations are in SSA form, which
2653makes things very simple. This section describes how to read, write,
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2654allocate, and free memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2655
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2656</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2657
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2658<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2659<div class="doc_subsubsection">
2660 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
2661</div>
2662
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2663<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2664
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2665<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2666
2667<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2668 &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]2669</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2670
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2671<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2672
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2673<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame^]2674heap and returns a pointer to it. The object is always allocated in the generic
2675address space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2676
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2677<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2678
2679<p>The '<tt>malloc</tt>' instruction allocates
2680<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswell6e4ca612004-02-24 16:13:56 +0000[diff] [blame]2681bytes of memory from the operating system and returns a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2682appropriate type to the program. If "NumElements" is specified, it is the
2683number of elements allocated. If an alignment is specified, the value result
2684of the allocation is guaranteed to be aligned to at least that boundary. If
2685not specified, or if zero, the target can choose to align the allocation on any
2686convenient boundary.</p>
2687
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2688<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2689
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2690<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2691
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2692<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
2693a pointer is returned.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2694
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2695<h5>Example:</h5>
2696
2697<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2698 %array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2699
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2700 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
2701 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
2702 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
2703 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
2704 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2705</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2706</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2707
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2708<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2709<div class="doc_subsubsection">
2710 <a name="i_free">'<tt>free</tt>' Instruction</a>
2711</div>
2712
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2713<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2714
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2715<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2716
2717<pre>
2718 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2719</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2720
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2721<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2722
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2723<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2724memory heap to be reallocated in the future.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2725
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2726<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2727
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2728<p>'<tt>value</tt>' shall be a pointer value that points to a value
2729that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
2730instruction.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2731
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2732<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2733
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2734<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2735after this instruction executes.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2736
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2737<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2738
2739<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2740 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
2741 free [4 x i8]* %array
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2742</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2743</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2744
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2745<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2746<div class="doc_subsubsection">
2747 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
2748</div>
2749
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2750<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2751
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2752<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2753
2754<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2755 &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]2756</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2757
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2758<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2759
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2760<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
2761currently executing function, to be automatically released when this function
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame^]2762returns to its caller. The object is always allocated in the generic address
2763space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2764
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2765<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2766
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2767<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2768bytes of memory on the runtime stack, returning a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2769appropriate type to the program. If "NumElements" is specified, it is the
2770number of elements allocated. If an alignment is specified, the value result
2771of the allocation is guaranteed to be aligned to at least that boundary. If
2772not specified, or if zero, the target can choose to align the allocation on any
2773convenient boundary.</p>
2774
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2775<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2776
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2777<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2778
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2779<p>Memory is allocated; a pointer is returned. '<tt>alloca</tt>'d
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2780memory is automatically released when the function returns. The '<tt>alloca</tt>'
2781instruction is commonly used to represent automatic variables that must
2782have an address available. When the function returns (either with the <tt><a
John Criswelldae2e932005-05-12 16:55:34 +0000[diff] [blame]2783 href="#i_ret">ret</a></tt> or <tt><a href="#i_unwind">unwind</a></tt>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2784instructions), the memory is reclaimed.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2785
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2786<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2787
2788<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2789 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2790 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
2791 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2792 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2793</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2794</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2795
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2796<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2797<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
2798Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2799<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2800<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]2801<pre> &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]<br> &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]<br></pre>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2802<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2803<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2804<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2805<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]2806address from which to load. The pointer must point to a <a
Chris Lattnere53e5082004-06-03 22:57:15 +0000[diff] [blame]2807 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]2808marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2809the number or order of execution of this <tt>load</tt> with other
2810volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
2811instructions. </p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2812<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2813<p>The location of memory pointed to is loaded.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2814<h5>Examples:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2815<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2816 <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2817 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
2818 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2819</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2820</div>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2821<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2822<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
2823Instruction</a> </div>
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]2824<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2825<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]2826<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
2827 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]2828</pre>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2829<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2830<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2831<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2832<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2833to store and an address at which to store it. The type of the '<tt>&lt;pointer&gt;</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2834operand must be a pointer to the type of the '<tt>&lt;value&gt;</tt>'
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2835operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2836optimizer is not allowed to modify the number or order of execution of
2837this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
2838 href="#i_store">store</a></tt> instructions.</p>
2839<h5>Semantics:</h5>
2840<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
2841at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2842<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2843<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]2844 store i32 3, i32* %ptr <i>; yields {void}</i>
2845 %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]2846</pre>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]2847</div>
2848
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2849<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2850<div class="doc_subsubsection">
2851 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
2852</div>
2853
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2854<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2855<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2856<pre>
2857 &lt;result&gt; = getelementptr &lt;ty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
2858</pre>
2859
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2860<h5>Overview:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2861
2862<p>
2863The '<tt>getelementptr</tt>' instruction is used to get the address of a
2864subelement of an aggregate data structure.</p>
2865
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2866<h5>Arguments:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2867
Reid Spencer85f5b5b2006-12-04 21:29:24 +0000[diff] [blame]2868<p>This instruction takes a list of integer operands that indicate what
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2869elements of the aggregate object to index to. The actual types of the arguments
2870provided depend on the type of the first pointer argument. The
2871'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]2872levels of a structure or to a specific index in an array. When indexing into a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2873structure, only <tt>i32</tt> integer constants are allowed. When indexing
Reid Spencer85f5b5b2006-12-04 21:29:24 +0000[diff] [blame]2874into an array or pointer, only integers of 32 or 64 bits are allowed, and will
2875be sign extended to 64-bit values.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2876
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2877<p>For example, let's consider a C code fragment and how it gets
2878compiled to LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2879
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2880<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2881<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2882struct RT {
2883 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]2884 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2885 char C;
2886};
2887struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]2888 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2889 double Y;
2890 struct RT Z;
2891};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2892
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]2893int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2894 return &amp;s[1].Z.B[5][13];
2895}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2896</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2897</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2898
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2899<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2900
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2901<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2902<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2903%RT = type { i8 , [10 x [20 x i32]], i8 }
2904%ST = type { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2905
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2906define i32* %foo(%ST* %s) {
2907entry:
2908 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
2909 ret i32* %reg
2910}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2911</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2912</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2913
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2914<h5>Semantics:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2915
2916<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2917on the pointer type that is being indexed into. <a href="#t_pointer">Pointer</a>
Reid Spencer85f5b5b2006-12-04 21:29:24 +0000[diff] [blame]2918and <a href="#t_array">array</a> types can use a 32-bit or 64-bit
Reid Spencer42ddd842006-12-03 16:53:48 +0000[diff] [blame]2919<a href="#t_integer">integer</a> type but the value will always be sign extended
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2920to 64-bits. <a href="#t_struct">Structure</a> types require <tt>i32</tt>
Reid Spencer42ddd842006-12-03 16:53:48 +0000[diff] [blame]2921<b>constants</b>.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2922
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2923<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2924type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2925}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2926the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
2927i8 }</tt>' type, another structure. The third index indexes into the second
2928element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2929array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2930'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
2931to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2932
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2933<p>Note that it is perfectly legal to index partially through a
2934structure, returning a pointer to an inner element. Because of this,
2935the LLVM code for the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2936
2937<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2938 define i32* %foo(%ST* %s) {
2939 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2940 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
2941 %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]2942 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
2943 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
2944 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2945 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2946</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]2947
2948<p>Note that it is undefined to access an array out of bounds: array and
2949pointer indexes must always be within the defined bounds of the array type.
2950The one exception for this rules is zero length arrays. These arrays are
2951defined to be accessible as variable length arrays, which requires access
2952beyond the zero'th element.</p>
2953
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]2954<p>The getelementptr instruction is often confusing. For some more insight
2955into how it works, see <a href="GetElementPtr.html">the getelementptr
2956FAQ</a>.</p>
2957
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2958<h5>Example:</h5>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]2959
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2960<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2961 <i>; yields [12 x i8]*:aptr</i>
2962 %aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2963</pre>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2964</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]2965
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2966<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]2967<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2968</div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2969<div class="doc_text">
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]2970<p>The instructions in this category are the conversion instructions (casting)
2971which all take a single operand and a type. They perform various bit conversions
2972on the operand.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2973</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]2974
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2975<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]2976<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2977 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
2978</div>
2979<div class="doc_text">
2980
2981<h5>Syntax:</h5>
2982<pre>
2983 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
2984</pre>
2985
2986<h5>Overview:</h5>
2987<p>
2988The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
2989</p>
2990
2991<h5>Arguments:</h5>
2992<p>
2993The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
2994be an <a href="#t_integer">integer</a> type, and a type that specifies the size
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]2995and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2996type. The bit size of <tt>value</tt> must be larger than the bit size of
2997<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2998
2999<h5>Semantics:</h5>
3000<p>
3001The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3002and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
3003larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
3004It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3005
3006<h5>Example:</h5>
3007<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3008 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3009 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
3010 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3011</pre>
3012</div>
3013
3014<!-- _______________________________________________________________________ -->
3015<div class="doc_subsubsection">
3016 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
3017</div>
3018<div class="doc_text">
3019
3020<h5>Syntax:</h5>
3021<pre>
3022 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3023</pre>
3024
3025<h5>Overview:</h5>
3026<p>The '<tt>zext</tt>' instruction zero extends its operand to type
3027<tt>ty2</tt>.</p>
3028
3029
3030<h5>Arguments:</h5>
3031<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3032<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3033also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3034<tt>value</tt> must be smaller than the bit size of the destination type,
3035<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3036
3037<h5>Semantics:</h5>
3038<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Chris Lattnerd1d25172007-05-24 19:13:27 +0000[diff] [blame]3039bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3040
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]3041<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]3042
3043<h5>Example:</h5>
3044<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3045 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3046 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3047</pre>
3048</div>
3049
3050<!-- _______________________________________________________________________ -->
3051<div class="doc_subsubsection">
3052 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3053</div>
3054<div class="doc_text">
3055
3056<h5>Syntax:</h5>
3057<pre>
3058 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3059</pre>
3060
3061<h5>Overview:</h5>
3062<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3063
3064<h5>Arguments:</h5>
3065<p>
3066The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3067<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3068also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3069<tt>value</tt> must be smaller than the bit size of the destination type,
3070<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3071
3072<h5>Semantics:</h5>
3073<p>
3074The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3075bit (highest order bit) of the <tt>value</tt> until it reaches the bit size of
Chris Lattnerd1d25172007-05-24 19:13:27 +0000[diff] [blame]3076the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3077
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3078<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]3079
3080<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3081<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3082 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3083 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3084</pre>
3085</div>
3086
3087<!-- _______________________________________________________________________ -->
3088<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3089 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3090</div>
3091
3092<div class="doc_text">
3093
3094<h5>Syntax:</h5>
3095
3096<pre>
3097 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3098</pre>
3099
3100<h5>Overview:</h5>
3101<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3102<tt>ty2</tt>.</p>
3103
3104
3105<h5>Arguments:</h5>
3106<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3107 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3108cast it to. The size of <tt>value</tt> must be larger than the size of
3109<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3110<i>no-op cast</i>.</p>
3111
3112<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3113<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3114<a href="#t_floating">floating point</a> type to a smaller
3115<a href="#t_floating">floating point</a> type. If the value cannot fit within
3116the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3117
3118<h5>Example:</h5>
3119<pre>
3120 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3121 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3122</pre>
3123</div>
3124
3125<!-- _______________________________________________________________________ -->
3126<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3127 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3128</div>
3129<div class="doc_text">
3130
3131<h5>Syntax:</h5>
3132<pre>
3133 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3134</pre>
3135
3136<h5>Overview:</h5>
3137<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3138floating point value.</p>
3139
3140<h5>Arguments:</h5>
3141<p>The '<tt>fpext</tt>' instruction takes a
3142<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3143and a <a href="#t_floating">floating point</a> type to cast it to. The source
3144type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3145
3146<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3147<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3148<a href="#t_floating">floating point</a> type to a larger
3149<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3150used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3151<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]3152
3153<h5>Example:</h5>
3154<pre>
3155 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3156 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3157</pre>
3158</div>
3159
3160<!-- _______________________________________________________________________ -->
3161<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]3162 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3163</div>
3164<div class="doc_text">
3165
3166<h5>Syntax:</h5>
3167<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3168 &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]3169</pre>
3170
3171<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3172<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3173unsigned integer equivalent of type <tt>ty2</tt>.
3174</p>
3175
3176<h5>Arguments:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3177<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3178scalar or vector <a href="#t_floating">floating point</a> value, and a type
3179to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3180type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3181vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3182
3183<h5>Semantics:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3184<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3185<a href="#t_floating">floating point</a> operand into the nearest (rounding
3186towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3187the results are undefined.</p>
3188
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3189<h5>Example:</h5>
3190<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3191 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3192 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3193 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3194</pre>
3195</div>
3196
3197<!-- _______________________________________________________________________ -->
3198<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3199 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3200</div>
3201<div class="doc_text">
3202
3203<h5>Syntax:</h5>
3204<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3205 &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]3206</pre>
3207
3208<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3209<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3210<a href="#t_floating">floating point</a> <tt>value</tt> to type <tt>ty2</tt>.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3211</p>
3212
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3213<h5>Arguments:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3214<p> The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3215scalar or vector <a href="#t_floating">floating point</a> value, and a type
3216to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3217type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3218vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3219
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3220<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3221<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3222<a href="#t_floating">floating point</a> operand into the nearest (rounding
3223towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3224the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3225
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3226<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3227<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3228 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3229 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3230 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3231</pre>
3232</div>
3233
3234<!-- _______________________________________________________________________ -->
3235<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3236 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3237</div>
3238<div class="doc_text">
3239
3240<h5>Syntax:</h5>
3241<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3242 &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]3243</pre>
3244
3245<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3246<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3247integer and converts that value to the <tt>ty2</tt> type.</p>
3248
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3249<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3250<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3251scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3252to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3253type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3254floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3255
3256<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3257<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3258integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3259the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3260
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3261<h5>Example:</h5>
3262<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3263 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3264 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3265</pre>
3266</div>
3267
3268<!-- _______________________________________________________________________ -->
3269<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3270 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3271</div>
3272<div class="doc_text">
3273
3274<h5>Syntax:</h5>
3275<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3276 &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]3277</pre>
3278
3279<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3280<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3281integer and converts that value to the <tt>ty2</tt> type.</p>
3282
3283<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3284<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3285scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3286to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3287type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3288floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3289
3290<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3291<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3292integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3293the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3294
3295<h5>Example:</h5>
3296<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3297 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3298 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3299</pre>
3300</div>
3301
3302<!-- _______________________________________________________________________ -->
3303<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3304 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3305</div>
3306<div class="doc_text">
3307
3308<h5>Syntax:</h5>
3309<pre>
3310 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3311</pre>
3312
3313<h5>Overview:</h5>
3314<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3315the integer type <tt>ty2</tt>.</p>
3316
3317<h5>Arguments:</h5>
3318<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3319must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3320<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
3321
3322<h5>Semantics:</h5>
3323<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3324<tt>ty2</tt> by interpreting the pointer value as an integer and either
3325truncating or zero extending that value to the size of the integer type. If
3326<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3327<tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3328are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3329change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3330
3331<h5>Example:</h5>
3332<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3333 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3334 %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]3335</pre>
3336</div>
3337
3338<!-- _______________________________________________________________________ -->
3339<div class="doc_subsubsection">
3340 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3341</div>
3342<div class="doc_text">
3343
3344<h5>Syntax:</h5>
3345<pre>
3346 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3347</pre>
3348
3349<h5>Overview:</h5>
3350<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
3351a pointer type, <tt>ty2</tt>.</p>
3352
3353<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3354<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3355value to cast, and a type to cast it to, which must be a
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]3356<a href="#t_pointer">pointer</a> type.
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3357
3358<h5>Semantics:</h5>
3359<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
3360<tt>ty2</tt> by applying either a zero extension or a truncation depending on
3361the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
3362size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
3363the size of a pointer then a zero extension is done. If they are the same size,
3364nothing is done (<i>no-op cast</i>).</p>
3365
3366<h5>Example:</h5>
3367<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3368 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
3369 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
3370 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3371</pre>
3372</div>
3373
3374<!-- _______________________________________________________________________ -->
3375<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3376 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3377</div>
3378<div class="doc_text">
3379
3380<h5>Syntax:</h5>
3381<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3382 &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]3383</pre>
3384
3385<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3386<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3387<tt>ty2</tt> without changing any bits.</p>
3388
3389<h5>Arguments:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3390<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3391a first class value, and a type to cast it to, which must also be a <a
3392 href="#t_firstclass">first class</a> type. The bit sizes of <tt>value</tt>
Reid Spencer19b569f2007-01-09 20:08:58 +0000[diff] [blame]3393and the destination type, <tt>ty2</tt>, must be identical. If the source
3394type is a pointer, the destination type must also be a pointer.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3395
3396<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3397<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3398<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
3399this conversion. The conversion is done as if the <tt>value</tt> had been
3400stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
3401converted to other pointer types with this instruction. To convert pointers to
3402other types, use the <a href="#i_inttoptr">inttoptr</a> or
3403<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3404
3405<h5>Example:</h5>
3406<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3407 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3408 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
3409 %Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3410</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3411</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3412
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3413<!-- ======================================================================= -->
3414<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
3415<div class="doc_text">
3416<p>The instructions in this category are the "miscellaneous"
3417instructions, which defy better classification.</p>
3418</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3419
3420<!-- _______________________________________________________________________ -->
3421<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
3422</div>
3423<div class="doc_text">
3424<h5>Syntax:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3425<pre> &lt;result&gt; = icmp &lt;cond&gt; &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {i1}:result</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3426</pre>
3427<h5>Overview:</h5>
3428<p>The '<tt>icmp</tt>' instruction returns a boolean value based on comparison
3429of its two integer operands.</p>
3430<h5>Arguments:</h5>
3431<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3432the condition code indicating the kind of comparison to perform. It is not
3433a value, just a keyword. The possible condition code are:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3434<ol>
3435 <li><tt>eq</tt>: equal</li>
3436 <li><tt>ne</tt>: not equal </li>
3437 <li><tt>ugt</tt>: unsigned greater than</li>
3438 <li><tt>uge</tt>: unsigned greater or equal</li>
3439 <li><tt>ult</tt>: unsigned less than</li>
3440 <li><tt>ule</tt>: unsigned less or equal</li>
3441 <li><tt>sgt</tt>: signed greater than</li>
3442 <li><tt>sge</tt>: signed greater or equal</li>
3443 <li><tt>slt</tt>: signed less than</li>
3444 <li><tt>sle</tt>: signed less or equal</li>
3445</ol>
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3446<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Reid Spencer350f8aa2007-01-04 05:19:58 +0000[diff] [blame]3447<a href="#t_pointer">pointer</a> typed. They must also be identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3448<h5>Semantics:</h5>
3449<p>The '<tt>icmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
3450the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3451yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3452<ol>
3453 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
3454 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3455 </li>
3456 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
3457 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3458 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
3459 <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
3460 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
3461 <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
3462 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
3463 <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
3464 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
3465 <tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
3466 <li><tt>sgt</tt>: interprets the operands as signed values and yields
3467 <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
3468 <li><tt>sge</tt>: interprets the operands as signed values and yields
3469 <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
3470 <li><tt>slt</tt>: interprets the operands as signed values and yields
3471 <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
3472 <li><tt>sle</tt>: interprets the operands as signed values and yields
3473 <tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3474</ol>
3475<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3476values are compared as if they were integers.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3477
3478<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3479<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
3480 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
3481 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
3482 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
3483 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
3484 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3485</pre>
3486</div>
3487
3488<!-- _______________________________________________________________________ -->
3489<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
3490</div>
3491<div class="doc_text">
3492<h5>Syntax:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3493<pre> &lt;result&gt; = fcmp &lt;cond&gt; &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {i1}:result</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3494</pre>
3495<h5>Overview:</h5>
3496<p>The '<tt>fcmp</tt>' instruction returns a boolean value based on comparison
3497of its floating point operands.</p>
3498<h5>Arguments:</h5>
3499<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3500the condition code indicating the kind of comparison to perform. It is not
3501a value, just a keyword. The possible condition code are:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3502<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3503 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3504 <li><tt>oeq</tt>: ordered and equal</li>
3505 <li><tt>ogt</tt>: ordered and greater than </li>
3506 <li><tt>oge</tt>: ordered and greater than or equal</li>
3507 <li><tt>olt</tt>: ordered and less than </li>
3508 <li><tt>ole</tt>: ordered and less than or equal</li>
3509 <li><tt>one</tt>: ordered and not equal</li>
3510 <li><tt>ord</tt>: ordered (no nans)</li>
3511 <li><tt>ueq</tt>: unordered or equal</li>
3512 <li><tt>ugt</tt>: unordered or greater than </li>
3513 <li><tt>uge</tt>: unordered or greater than or equal</li>
3514 <li><tt>ult</tt>: unordered or less than </li>
3515 <li><tt>ule</tt>: unordered or less than or equal</li>
3516 <li><tt>une</tt>: unordered or not equal</li>
3517 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3518 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3519</ol>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3520<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer93a49852006-12-06 07:08:07 +0000[diff] [blame]3521<i>unordered</i> means that either operand may be a QNAN.</p>
Reid Spencer350f8aa2007-01-04 05:19:58 +0000[diff] [blame]3522<p>The <tt>val1</tt> and <tt>val2</tt> arguments must be
3523<a href="#t_floating">floating point</a> typed. They must have identical
3524types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3525<h5>Semantics:</h5>
3526<p>The '<tt>fcmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
3527the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3528yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3529<ol>
3530 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3531 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3532 <tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3533 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3534 <tt>var1</tt> is greather than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3535 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3536 <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3537 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3538 <tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3539 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3540 <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3541 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3542 <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3543 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
3544 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3545 <tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3546 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3547 <tt>var1</tt> is greater than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3548 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3549 <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3550 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3551 <tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3552 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3553 <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3554 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3555 <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3556 <li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3557 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
3558</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3559
3560<h5>Example:</h5>
3561<pre> &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
3562 &lt;result&gt; = icmp one float 4.0, 5.0 <i>; yields: result=true</i>
3563 &lt;result&gt; = icmp olt float 4.0, 5.0 <i>; yields: result=true</i>
3564 &lt;result&gt; = icmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
3565</pre>
3566</div>
3567
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3568<!-- _______________________________________________________________________ -->
3569<div class="doc_subsubsection"> <a name="i_phi">'<tt>phi</tt>'
3570Instruction</a> </div>
3571<div class="doc_text">
3572<h5>Syntax:</h5>
3573<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
3574<h5>Overview:</h5>
3575<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
3576the SSA graph representing the function.</p>
3577<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3578<p>The type of the incoming values is specified with the first type
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3579field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
3580as arguments, with one pair for each predecessor basic block of the
3581current block. Only values of <a href="#t_firstclass">first class</a>
3582type may be used as the value arguments to the PHI node. Only labels
3583may be used as the label arguments.</p>
3584<p>There must be no non-phi instructions between the start of a basic
3585block and the PHI instructions: i.e. PHI instructions must be first in
3586a basic block.</p>
3587<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3588<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
3589specified by the pair corresponding to the predecessor basic block that executed
3590just prior to the current block.</p>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3591<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3592<pre>Loop: ; Infinite loop that counts from 0 on up...<br> %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]<br> %nextindvar = add i32 %indvar, 1<br> br label %Loop<br></pre>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3593</div>
3594
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3595<!-- _______________________________________________________________________ -->
3596<div class="doc_subsubsection">
3597 <a name="i_select">'<tt>select</tt>' Instruction</a>
3598</div>
3599
3600<div class="doc_text">
3601
3602<h5>Syntax:</h5>
3603
3604<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3605 &lt;result&gt; = select i1 &lt;cond&gt;, &lt;ty&gt; &lt;val1&gt;, &lt;ty&gt; &lt;val2&gt; <i>; yields ty</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3606</pre>
3607
3608<h5>Overview:</h5>
3609
3610<p>
3611The '<tt>select</tt>' instruction is used to choose one value based on a
3612condition, without branching.
3613</p>
3614
3615
3616<h5>Arguments:</h5>
3617
3618<p>
3619The '<tt>select</tt>' instruction requires a boolean value indicating the condition, and two values of the same <a href="#t_firstclass">first class</a> type.
3620</p>
3621
3622<h5>Semantics:</h5>
3623
3624<p>
3625If the boolean condition evaluates to true, the instruction returns the first
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3626value argument; otherwise, it returns the second value argument.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3627</p>
3628
3629<h5>Example:</h5>
3630
3631<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3632 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3633</pre>
3634</div>
3635
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]3636
3637<!-- _______________________________________________________________________ -->
3638<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3639 <a name="i_call">'<tt>call</tt>' Instruction</a>
3640</div>
3641
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3642<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3643
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3644<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3645<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]3646 &lt;result&gt; = [tail] call [<a href="#callingconv">cconv</a>] &lt;ty&gt; [&lt;fnty&gt;*] &lt;fnptrval&gt;(&lt;param list&gt;)
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3647</pre>
3648
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3649<h5>Overview:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3650
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3651<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3652
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3653<h5>Arguments:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3654
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3655<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3656
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3657<ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3658 <li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3659 <p>The optional "tail" marker indicates whether the callee function accesses
3660 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3661 function call is eligible for tail call optimization. Note that calls may
3662 be marked "tail" even if they do not occur before a <a
3663 href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3664 </li>
3665 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3666 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3667 convention</a> the call should use. If none is specified, the call defaults
3668 to using C calling conventions.
3669 </li>
3670 <li>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]3671 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
3672 the type of the return value. Functions that return no value are marked
3673 <tt><a href="#t_void">void</a></tt>.</p>
3674 </li>
3675 <li>
3676 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
3677 value being invoked. The argument types must match the types implied by
3678 this signature. This type can be omitted if the function is not varargs
3679 and if the function type does not return a pointer to a function.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3680 </li>
3681 <li>
3682 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
3683 be invoked. In most cases, this is a direct function invocation, but
3684 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3685 to function value.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3686 </li>
3687 <li>
3688 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencera7e302a2005-05-01 22:22:57 +0000[diff] [blame]3689 function signature argument types. All arguments must be of
3690 <a href="#t_firstclass">first class</a> type. If the function signature
3691 indicates the function accepts a variable number of arguments, the extra
3692 arguments can be specified.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3693 </li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3694</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3695
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3696<h5>Semantics:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3697
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3698<p>The '<tt>call</tt>' instruction is used to cause control flow to
3699transfer to a specified function, with its incoming arguments bound to
3700the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
3701instruction in the called function, control flow continues with the
3702instruction after the function call, and the return value of the
3703function is bound to the result argument. This is a simpler case of
3704the <a href="#i_invoke">invoke</a> instruction.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3705
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3706<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3707
3708<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]3709 %retval = call i32 @test(i32 %argc)
3710 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42);
3711 %X = tail call i32 @foo()
3712 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo()
3713 %Z = call void %foo(i8 97 signext)
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3714</pre>
3715
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3716</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3717
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3718<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3719<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]3720 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3721</div>
3722
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3723<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3724
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3725<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3726
3727<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3728 &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]3729</pre>
3730
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3731<h5>Overview:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3732
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3733<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3734the "variable argument" area of a function call. It is used to implement the
3735<tt>va_arg</tt> macro in C.</p>
3736
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3737<h5>Arguments:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3738
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3739<p>This instruction takes a <tt>va_list*</tt> value and the type of
3740the argument. It returns a value of the specified argument type and
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3741increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3742actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3743
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3744<h5>Semantics:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3745
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3746<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
3747type from the specified <tt>va_list</tt> and causes the
3748<tt>va_list</tt> to point to the next argument. For more information,
3749see the variable argument handling <a href="#int_varargs">Intrinsic
3750Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3751
3752<p>It is legal for this instruction to be called in a function which does not
3753take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3754function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3755
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3756<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3757href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3758argument.</p>
3759
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3760<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3761
3762<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
3763
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3764</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3765
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3766<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3767<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
3768<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3769
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3770<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3771
3772<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]3773well known names and semantics and are required to follow certain restrictions.
3774Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3775language that does not require changing all of the transformations in LLVM when
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]3776adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3777
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3778<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3779prefix is reserved in LLVM for intrinsic names; thus, function names may not
3780begin with this prefix. Intrinsic functions must always be external functions:
3781you cannot define the body of intrinsic functions. Intrinsic functions may
3782only be used in call or invoke instructions: it is illegal to take the address
3783of an intrinsic function. Additionally, because intrinsic functions are part
3784of the LLVM language, it is required if any are added that they be documented
3785here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3786
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]3787<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
3788a family of functions that perform the same operation but on different data
3789types. Because LLVM can represent over 8 million different integer types,
3790overloading is used commonly to allow an intrinsic function to operate on any
3791integer type. One or more of the argument types or the result type can be
3792overloaded to accept any integer type. Argument types may also be defined as
3793exactly matching a previous argument's type or the result type. This allows an
3794intrinsic function which accepts multiple arguments, but needs all of them to
3795be of the same type, to only be overloaded with respect to a single argument or
3796the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3797
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]3798<p>Overloaded intrinsics will have the names of its overloaded argument types
3799encoded into its function name, each preceded by a period. Only those types
3800which are overloaded result in a name suffix. Arguments whose type is matched
3801against another type do not. For example, the <tt>llvm.ctpop</tt> function can
3802take an integer of any width and returns an integer of exactly the same integer
3803width. This leads to a family of functions such as
3804<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
3805Only one type, the return type, is overloaded, and only one type suffix is
3806required. Because the argument's type is matched against the return type, it
3807does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]3808
3809<p>To learn how to add an intrinsic function, please see the
3810<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3811</p>
3812
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3813</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3814
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3815<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3816<div class="doc_subsection">
3817 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
3818</div>
3819
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3820<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3821
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3822<p>Variable argument support is defined in LLVM with the <a
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]3823 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3824intrinsic functions. These functions are related to the similarly
3825named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3826
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3827<p>All of these functions operate on arguments that use a
3828target-specific value type "<tt>va_list</tt>". The LLVM assembly
3829language reference manual does not define what this type is, so all
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3830transformations should be prepared to handle these functions regardless of
3831the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3832
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]3833<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3834instruction and the variable argument handling intrinsic functions are
3835used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3836
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3837<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3838<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3839define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3840 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3841 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3842 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3843 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3844
3845 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3846 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3847
3848 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3849 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3850 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3851 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3852 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3853
3854 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3855 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3856 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3857}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3858
3859declare void @llvm.va_start(i8*)
3860declare void @llvm.va_copy(i8*, i8*)
3861declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3862</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3863</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3864
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3865</div>
3866
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3867<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3868<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3869 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3870</div>
3871
3872
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3873<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3874<h5>Syntax:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3875<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3876<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3877<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
3878<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
3879href="#i_va_arg">va_arg</a></tt>.</p>
3880
3881<h5>Arguments:</h5>
3882
3883<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
3884
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3885<h5>Semantics:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3886
3887<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
3888macro available in C. In a target-dependent way, it initializes the
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3889<tt>va_list</tt> element to which the argument points, so that the next call to
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3890<tt>va_arg</tt> will produce the first variable argument passed to the function.
3891Unlike the C <tt>va_start</tt> macro, this intrinsic does not need to know the
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3892last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3893
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3894</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3895
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3896<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3897<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3898 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3899</div>
3900
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3901<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3902<h5>Syntax:</h5>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]3903<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3904<h5>Overview:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3905
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3906<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3907which has been initialized previously with <tt><a href="#int_va_start">llvm.va_start</a></tt>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3908or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3909
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3910<h5>Arguments:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3911
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3912<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]3913
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3914<h5>Semantics:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3915
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3916<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3917macro available in C. In a target-dependent way, it destroys the
3918<tt>va_list</tt> element to which the argument points. Calls to <a
3919href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
3920<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
3921<tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3922
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3923</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3924
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3925<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3926<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3927 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3928</div>
3929
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3930<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3931
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3932<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3933
3934<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]3935 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3936</pre>
3937
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3938<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3939
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3940<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
3941from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3942
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3943<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3944
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3945<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Andrew Lenharthd0a4c622005-06-22 20:38:11 +0000[diff] [blame]3946The second argument is a pointer to a <tt>va_list</tt> element to copy from.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3947
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3948
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3949<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3950
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3951<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
3952macro available in C. In a target-dependent way, it copies the source
3953<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
3954intrinsic is necessary because the <tt><a href="#int_va_start">
3955llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
3956example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3957
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3958</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3959
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3960<!-- ======================================================================= -->
3961<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3962 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
3963</div>
3964
3965<div class="doc_text">
3966
3967<p>
3968LLVM support for <a href="GarbageCollection.html">Accurate Garbage
3969Collection</a> requires the implementation and generation of these intrinsics.
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3970These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3971stack</a>, as well as garbage collector implementations that require <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3972href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3973Front-ends for type-safe garbage collected languages should generate these
3974intrinsics to make use of the LLVM garbage collectors. For more details, see <a
3975href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
3976</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame^]3977
3978<p>The garbage collection intrinsics only operate on objects in the generic
3979 address space (address space zero).</p>
3980
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3981</div>
3982
3983<!-- _______________________________________________________________________ -->
3984<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3985 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3986</div>
3987
3988<div class="doc_text">
3989
3990<h5>Syntax:</h5>
3991
3992<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]3993 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3994</pre>
3995
3996<h5>Overview:</h5>
3997
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3998<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3999the code generator, and allows some metadata to be associated with it.</p>
4000
4001<h5>Arguments:</h5>
4002
4003<p>The first argument specifies the address of a stack object that contains the
4004root pointer. The second pointer (which must be either a constant or a global
4005value address) contains the meta-data to be associated with the root.</p>
4006
4007<h5>Semantics:</h5>
4008
4009<p>At runtime, a call to this intrinsics stores a null pointer into the "ptrloc"
4010location. At compile-time, the code generator generates information to allow
4011the runtime to find the pointer at GC safe points.
4012</p>
4013
4014</div>
4015
4016
4017<!-- _______________________________________________________________________ -->
4018<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4019 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4020</div>
4021
4022<div class="doc_text">
4023
4024<h5>Syntax:</h5>
4025
4026<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4027 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4028</pre>
4029
4030<h5>Overview:</h5>
4031
4032<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4033locations, allowing garbage collector implementations that require read
4034barriers.</p>
4035
4036<h5>Arguments:</h5>
4037
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4038<p>The second argument is the address to read from, which should be an address
4039allocated from the garbage collector. The first object is a pointer to the
4040start of the referenced object, if needed by the language runtime (otherwise
4041null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4042
4043<h5>Semantics:</h5>
4044
4045<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4046instruction, but may be replaced with substantially more complex code by the
4047garbage collector runtime, as needed.</p>
4048
4049</div>
4050
4051
4052<!-- _______________________________________________________________________ -->
4053<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4054 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4055</div>
4056
4057<div class="doc_text">
4058
4059<h5>Syntax:</h5>
4060
4061<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4062 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4063</pre>
4064
4065<h5>Overview:</h5>
4066
4067<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4068locations, allowing garbage collector implementations that require write
4069barriers (such as generational or reference counting collectors).</p>
4070
4071<h5>Arguments:</h5>
4072
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4073<p>The first argument is the reference to store, the second is the start of the
4074object to store it to, and the third is the address of the field of Obj to
4075store to. If the runtime does not require a pointer to the object, Obj may be
4076null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4077
4078<h5>Semantics:</h5>
4079
4080<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4081instruction, but may be replaced with substantially more complex code by the
4082garbage collector runtime, as needed.</p>
4083
4084</div>
4085
4086
4087
4088<!-- ======================================================================= -->
4089<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4090 <a name="int_codegen">Code Generator Intrinsics</a>
4091</div>
4092
4093<div class="doc_text">
4094<p>
4095These intrinsics are provided by LLVM to expose special features that may only
4096be implemented with code generator support.
4097</p>
4098
4099</div>
4100
4101<!-- _______________________________________________________________________ -->
4102<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4103 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4104</div>
4105
4106<div class="doc_text">
4107
4108<h5>Syntax:</h5>
4109<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4110 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4111</pre>
4112
4113<h5>Overview:</h5>
4114
4115<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4116The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4117target-specific value indicating the return address of the current function
4118or one of its callers.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4119</p>
4120
4121<h5>Arguments:</h5>
4122
4123<p>
4124The argument to this intrinsic indicates which function to return the address
4125for. Zero indicates the calling function, one indicates its caller, etc. The
4126argument is <b>required</b> to be a constant integer value.
4127</p>
4128
4129<h5>Semantics:</h5>
4130
4131<p>
4132The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4133the return address of the specified call frame, or zero if it cannot be
4134identified. The value returned by this intrinsic is likely to be incorrect or 0
4135for arguments other than zero, so it should only be used for debugging purposes.
4136</p>
4137
4138<p>
4139Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4140aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4141source-language caller.
4142</p>
4143</div>
4144
4145
4146<!-- _______________________________________________________________________ -->
4147<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4148 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4149</div>
4150
4151<div class="doc_text">
4152
4153<h5>Syntax:</h5>
4154<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4155 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4156</pre>
4157
4158<h5>Overview:</h5>
4159
4160<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4161The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
4162target-specific frame pointer value for the specified stack frame.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4163</p>
4164
4165<h5>Arguments:</h5>
4166
4167<p>
4168The argument to this intrinsic indicates which function to return the frame
4169pointer for. Zero indicates the calling function, one indicates its caller,
4170etc. The argument is <b>required</b> to be a constant integer value.
4171</p>
4172
4173<h5>Semantics:</h5>
4174
4175<p>
4176The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
4177the frame address of the specified call frame, or zero if it cannot be
4178identified. The value returned by this intrinsic is likely to be incorrect or 0
4179for arguments other than zero, so it should only be used for debugging purposes.
4180</p>
4181
4182<p>
4183Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4184aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4185source-language caller.
4186</p>
4187</div>
4188
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4189<!-- _______________________________________________________________________ -->
4190<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4191 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4192</div>
4193
4194<div class="doc_text">
4195
4196<h5>Syntax:</h5>
4197<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4198 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4199</pre>
4200
4201<h5>Overview:</h5>
4202
4203<p>
4204The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4205the function stack, for use with <a href="#int_stackrestore">
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4206<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
4207features like scoped automatic variable sized arrays in C99.
4208</p>
4209
4210<h5>Semantics:</h5>
4211
4212<p>
4213This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4214href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4215<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
4216<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
4217state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
4218practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
4219that were allocated after the <tt>llvm.stacksave</tt> was executed.
4220</p>
4221
4222</div>
4223
4224<!-- _______________________________________________________________________ -->
4225<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4226 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4227</div>
4228
4229<div class="doc_text">
4230
4231<h5>Syntax:</h5>
4232<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4233 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4234</pre>
4235
4236<h5>Overview:</h5>
4237
4238<p>
4239The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
4240the function stack to the state it was in when the corresponding <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4241href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4242useful for implementing language features like scoped automatic variable sized
4243arrays in C99.
4244</p>
4245
4246<h5>Semantics:</h5>
4247
4248<p>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4249See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4250</p>
4251
4252</div>
4253
4254
4255<!-- _______________________________________________________________________ -->
4256<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4257 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4258</div>
4259
4260<div class="doc_text">
4261
4262<h5>Syntax:</h5>
4263<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4264 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]4265</pre>
4266
4267<h5>Overview:</h5>
4268
4269
4270<p>
4271The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4272a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
4273no
4274effect on the behavior of the program but can change its performance
Chris Lattner2a615362005-02-28 19:47:14 +0000[diff] [blame]4275characteristics.
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4276</p>
4277
4278<h5>Arguments:</h5>
4279
4280<p>
4281<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
4282determining if the fetch should be for a read (0) or write (1), and
4283<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattneraeffb4a2005-03-07 20:31:38 +0000[diff] [blame]4284locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4285<tt>locality</tt> arguments must be constant integers.
4286</p>
4287
4288<h5>Semantics:</h5>
4289
4290<p>
4291This intrinsic does not modify the behavior of the program. In particular,
4292prefetches cannot trap and do not produce a value. On targets that support this
4293intrinsic, the prefetch can provide hints to the processor cache for better
4294performance.
4295</p>
4296
4297</div>
4298
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4299<!-- _______________________________________________________________________ -->
4300<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4301 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4302</div>
4303
4304<div class="doc_text">
4305
4306<h5>Syntax:</h5>
4307<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4308 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4309</pre>
4310
4311<h5>Overview:</h5>
4312
4313
4314<p>
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4315The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
4316(PC) in a region of
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4317code to simulators and other tools. The method is target specific, but it is
4318expected that the marker will use exported symbols to transmit the PC of the marker.
Jeff Cohen25d4f7e2005-11-11 02:15:27 +0000[diff] [blame]4319The marker makes no guarantees that it will remain with any specific instruction
Chris Lattnerd07c3f42005-11-15 06:07:55 +0000[diff] [blame]4320after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb3e7afd2006-03-24 07:16:10 +0000[diff] [blame]4321optimizations. The intended use is to be inserted after optimizations to allow
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4322correlations of simulation runs.
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4323</p>
4324
4325<h5>Arguments:</h5>
4326
4327<p>
4328<tt>id</tt> is a numerical id identifying the marker.
4329</p>
4330
4331<h5>Semantics:</h5>
4332
4333<p>
4334This intrinsic does not modify the behavior of the program. Backends that do not
4335support this intrinisic may ignore it.
4336</p>
4337
4338</div>
4339
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]4340<!-- _______________________________________________________________________ -->
4341<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4342 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]4343</div>
4344
4345<div class="doc_text">
4346
4347<h5>Syntax:</h5>
4348<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4349 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]4350</pre>
4351
4352<h5>Overview:</h5>
4353
4354
4355<p>
4356The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
4357counter register (or similar low latency, high accuracy clocks) on those targets
4358that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
4359As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
4360should only be used for small timings.
4361</p>
4362
4363<h5>Semantics:</h5>
4364
4365<p>
4366When directly supported, reading the cycle counter should not modify any memory.
4367Implementations are allowed to either return a application specific value or a
4368system wide value. On backends without support, this is lowered to a constant 0.
4369</p>
4370
4371</div>
4372
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4373<!-- ======================================================================= -->
4374<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4375 <a name="int_libc">Standard C Library Intrinsics</a>
4376</div>
4377
4378<div class="doc_text">
4379<p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4380LLVM provides intrinsics for a few important standard C library functions.
4381These intrinsics allow source-language front-ends to pass information about the
4382alignment of the pointer arguments to the code generator, providing opportunity
4383for more efficient code generation.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4384</p>
4385
4386</div>
4387
4388<!-- _______________________________________________________________________ -->
4389<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4390 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4391</div>
4392
4393<div class="doc_text">
4394
4395<h5>Syntax:</h5>
4396<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4397 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4398 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4399 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4400 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4401</pre>
4402
4403<h5>Overview:</h5>
4404
4405<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4406The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4407location to the destination location.
4408</p>
4409
4410<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4411Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
4412intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4413</p>
4414
4415<h5>Arguments:</h5>
4416
4417<p>
4418The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4419the source. The third argument is an integer argument
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4420specifying the number of bytes to copy, and the fourth argument is the alignment
4421of the source and destination locations.
4422</p>
4423
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4424<p>
4425If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattnerf0afc2c2006-03-04 00:02:10 +0000[diff] [blame]4426the caller guarantees that both the source and destination pointers are aligned
4427to that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4428</p>
4429
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4430<h5>Semantics:</h5>
4431
4432<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4433The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4434location to the destination location, which are not allowed to overlap. It
4435copies "len" bytes of memory over. If the argument is known to be aligned to
4436some boundary, this can be specified as the fourth argument, otherwise it should
4437be set to 0 or 1.
4438</p>
4439</div>
4440
4441
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4442<!-- _______________________________________________________________________ -->
4443<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4444 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4445</div>
4446
4447<div class="doc_text">
4448
4449<h5>Syntax:</h5>
4450<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4451 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4452 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4453 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4454 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4455</pre>
4456
4457<h5>Overview:</h5>
4458
4459<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4460The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
4461location to the destination location. It is similar to the
4462'<tt>llvm.memcmp</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4463</p>
4464
4465<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4466Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
4467intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4468</p>
4469
4470<h5>Arguments:</h5>
4471
4472<p>
4473The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4474the source. The third argument is an integer argument
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4475specifying the number of bytes to copy, and the fourth argument is the alignment
4476of the source and destination locations.
4477</p>
4478
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4479<p>
4480If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattnerf0afc2c2006-03-04 00:02:10 +0000[diff] [blame]4481the caller guarantees that the source and destination pointers are aligned to
4482that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4483</p>
4484
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4485<h5>Semantics:</h5>
4486
4487<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4488The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4489location to the destination location, which may overlap. It
4490copies "len" bytes of memory over. If the argument is known to be aligned to
4491some boundary, this can be specified as the fourth argument, otherwise it should
4492be set to 0 or 1.
4493</p>
4494</div>
4495
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4496
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4497<!-- _______________________________________________________________________ -->
4498<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4499 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4500</div>
4501
4502<div class="doc_text">
4503
4504<h5>Syntax:</h5>
4505<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4506 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4507 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4508 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4509 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4510</pre>
4511
4512<h5>Overview:</h5>
4513
4514<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4515The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4516byte value.
4517</p>
4518
4519<p>
4520Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
4521does not return a value, and takes an extra alignment argument.
4522</p>
4523
4524<h5>Arguments:</h5>
4525
4526<p>
4527The first argument is a pointer to the destination to fill, the second is the
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4528byte value to fill it with, the third argument is an integer
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4529argument specifying the number of bytes to fill, and the fourth argument is the
4530known alignment of destination location.
4531</p>
4532
4533<p>
4534If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattnerf0afc2c2006-03-04 00:02:10 +0000[diff] [blame]4535the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4536</p>
4537
4538<h5>Semantics:</h5>
4539
4540<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4541The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
4542the
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4543destination location. If the argument is known to be aligned to some boundary,
4544this can be specified as the fourth argument, otherwise it should be set to 0 or
45451.
4546</p>
4547</div>
4548
4549
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]4550<!-- _______________________________________________________________________ -->
4551<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4552 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4553</div>
4554
4555<div class="doc_text">
4556
4557<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4558<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4559floating point or vector of floating point type. Not all targets support all
4560types however.
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4561<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4562 declare float @llvm.sqrt.f32(float %Val)
4563 declare double @llvm.sqrt.f64(double %Val)
4564 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
4565 declare fp128 @llvm.sqrt.f128(fp128 %Val)
4566 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4567</pre>
4568
4569<h5>Overview:</h5>
4570
4571<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4572The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4573returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4574<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
4575negative numbers (which allows for better optimization).
4576</p>
4577
4578<h5>Arguments:</h5>
4579
4580<p>
4581The argument and return value are floating point numbers of the same type.
4582</p>
4583
4584<h5>Semantics:</h5>
4585
4586<p>
Dan Gohmand6257fe2007-07-16 14:37:41 +0000[diff] [blame]4587This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4588floating point number.
4589</p>
4590</div>
4591
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4592<!-- _______________________________________________________________________ -->
4593<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4594 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4595</div>
4596
4597<div class="doc_text">
4598
4599<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4600<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4601floating point or vector of floating point type. Not all targets support all
4602types however.
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4603<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4604 declare float @llvm.powi.f32(float %Val, i32 %power)
4605 declare double @llvm.powi.f64(double %Val, i32 %power)
4606 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
4607 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
4608 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4609</pre>
4610
4611<h5>Overview:</h5>
4612
4613<p>
4614The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
4615specified (positive or negative) power. The order of evaluation of
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4616multiplications is not defined. When a vector of floating point type is
4617used, the second argument remains a scalar integer value.
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4618</p>
4619
4620<h5>Arguments:</h5>
4621
4622<p>
4623The second argument is an integer power, and the first is a value to raise to
4624that power.
4625</p>
4626
4627<h5>Semantics:</h5>
4628
4629<p>
4630This function returns the first value raised to the second power with an
4631unspecified sequence of rounding operations.</p>
4632</div>
4633
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4634<!-- _______________________________________________________________________ -->
4635<div class="doc_subsubsection">
4636 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
4637</div>
4638
4639<div class="doc_text">
4640
4641<h5>Syntax:</h5>
4642<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
4643floating point or vector of floating point type. Not all targets support all
4644types however.
4645<pre>
4646 declare float @llvm.sin.f32(float %Val)
4647 declare double @llvm.sin.f64(double %Val)
4648 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
4649 declare fp128 @llvm.sin.f128(fp128 %Val)
4650 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
4651</pre>
4652
4653<h5>Overview:</h5>
4654
4655<p>
4656The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
4657</p>
4658
4659<h5>Arguments:</h5>
4660
4661<p>
4662The argument and return value are floating point numbers of the same type.
4663</p>
4664
4665<h5>Semantics:</h5>
4666
4667<p>
4668This function returns the sine of the specified operand, returning the
4669same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]4670conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4671</div>
4672
4673<!-- _______________________________________________________________________ -->
4674<div class="doc_subsubsection">
4675 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
4676</div>
4677
4678<div class="doc_text">
4679
4680<h5>Syntax:</h5>
4681<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
4682floating point or vector of floating point type. Not all targets support all
4683types however.
4684<pre>
4685 declare float @llvm.cos.f32(float %Val)
4686 declare double @llvm.cos.f64(double %Val)
4687 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
4688 declare fp128 @llvm.cos.f128(fp128 %Val)
4689 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
4690</pre>
4691
4692<h5>Overview:</h5>
4693
4694<p>
4695The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
4696</p>
4697
4698<h5>Arguments:</h5>
4699
4700<p>
4701The argument and return value are floating point numbers of the same type.
4702</p>
4703
4704<h5>Semantics:</h5>
4705
4706<p>
4707This function returns the cosine of the specified operand, returning the
4708same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]4709conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4710</div>
4711
4712<!-- _______________________________________________________________________ -->
4713<div class="doc_subsubsection">
4714 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
4715</div>
4716
4717<div class="doc_text">
4718
4719<h5>Syntax:</h5>
4720<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
4721floating point or vector of floating point type. Not all targets support all
4722types however.
4723<pre>
4724 declare float @llvm.pow.f32(float %Val, float %Power)
4725 declare double @llvm.pow.f64(double %Val, double %Power)
4726 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
4727 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
4728 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
4729</pre>
4730
4731<h5>Overview:</h5>
4732
4733<p>
4734The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
4735specified (positive or negative) power.
4736</p>
4737
4738<h5>Arguments:</h5>
4739
4740<p>
4741The second argument is a floating point power, and the first is a value to
4742raise to that power.
4743</p>
4744
4745<h5>Semantics:</h5>
4746
4747<p>
4748This function returns the first value raised to the second power,
4749returning the
4750same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]4751conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4752</div>
4753
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4754
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4755<!-- ======================================================================= -->
4756<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4757 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4758</div>
4759
4760<div class="doc_text">
4761<p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4762LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4763These allow efficient code generation for some algorithms.
4764</p>
4765
4766</div>
4767
4768<!-- _______________________________________________________________________ -->
4769<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4770 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4771</div>
4772
4773<div class="doc_text">
4774
4775<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4776<p>This is an overloaded intrinsic function. You can use bswap on any integer
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4777type that is an even number of bytes (i.e. BitWidth % 16 == 0).
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4778<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4779 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
4780 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
4781 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4782</pre>
4783
4784<h5>Overview:</h5>
4785
4786<p>
Reid Spencer338ea092007-04-02 02:25:19 +0000[diff] [blame]4787The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4788values with an even number of bytes (positive multiple of 16 bits). These are
4789useful for performing operations on data that is not in the target's native
4790byte order.
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4791</p>
4792
4793<h5>Semantics:</h5>
4794
4795<p>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4796The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4797and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
4798intrinsic returns an i32 value that has the four bytes of the input i32
4799swapped, so that if the input bytes are numbered 0, 1, 2, 3 then the returned
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4800i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
4801<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4802additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4803</p>
4804
4805</div>
4806
4807<!-- _______________________________________________________________________ -->
4808<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4809 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4810</div>
4811
4812<div class="doc_text">
4813
4814<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4815<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
4816width. Not all targets support all bit widths however.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4817<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4818 declare i8 @llvm.ctpop.i8 (i8 &lt;src&gt;)
4819 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4820 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4821 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
4822 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4823</pre>
4824
4825<h5>Overview:</h5>
4826
4827<p>
Chris Lattnerec6cb612006-01-16 22:38:59 +0000[diff] [blame]4828The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
4829value.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4830</p>
4831
4832<h5>Arguments:</h5>
4833
4834<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]4835The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]4836integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4837</p>
4838
4839<h5>Semantics:</h5>
4840
4841<p>
4842The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
4843</p>
4844</div>
4845
4846<!-- _______________________________________________________________________ -->
4847<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]4848 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4849</div>
4850
4851<div class="doc_text">
4852
4853<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4854<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
4855integer bit width. Not all targets support all bit widths however.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4856<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4857 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
4858 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4859 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4860 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
4861 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4862</pre>
4863
4864<h5>Overview:</h5>
4865
4866<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4867The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
4868leading zeros in a variable.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4869</p>
4870
4871<h5>Arguments:</h5>
4872
4873<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]4874The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]4875integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4876</p>
4877
4878<h5>Semantics:</h5>
4879
4880<p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4881The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
4882in a variable. If the src == 0 then the result is the size in bits of the type
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4883of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4884</p>
4885</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]4886
4887
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4888
4889<!-- _______________________________________________________________________ -->
4890<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]4891 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4892</div>
4893
4894<div class="doc_text">
4895
4896<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4897<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
4898integer bit width. Not all targets support all bit widths however.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4899<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4900 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
4901 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4902 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4903 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
4904 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4905</pre>
4906
4907<h5>Overview:</h5>
4908
4909<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4910The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
4911trailing zeros.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4912</p>
4913
4914<h5>Arguments:</h5>
4915
4916<p>
4917The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]4918integer type. The return type must match the argument type.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4919</p>
4920
4921<h5>Semantics:</h5>
4922
4923<p>
4924The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
4925in a variable. If the src == 0 then the result is the size in bits of the type
4926of src. For example, <tt>llvm.cttz(2) = 1</tt>.
4927</p>
4928</div>
4929
Reid Spencer497d93e2007-04-01 08:27:01 +0000[diff] [blame]4930<!-- _______________________________________________________________________ -->
4931<div class="doc_subsubsection">
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4932 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4933</div>
4934
4935<div class="doc_text">
4936
4937<h5>Syntax:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4938<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4939on any integer bit width.
4940<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4941 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
4942 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4943</pre>
4944
4945<h5>Overview:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4946<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4947range of bits from an integer value and returns them in the same bit width as
4948the original value.</p>
4949
4950<h5>Arguments:</h5>
4951<p>The first argument, <tt>%val</tt> and the result may be integer types of
4952any bit width but they must have the same bit width. The second and third
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4953arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4954
4955<h5>Semantics:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4956<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4957of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
4958<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
4959operates in forward mode.</p>
4960<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
4961right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4962only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
4963<ol>
4964 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
4965 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
4966 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
4967 to determine the number of bits to retain.</li>
4968 <li>A mask of the retained bits is created by shifting a -1 value.</li>
4969 <li>The mask is ANDed with <tt>%val</tt> to produce the result.
4970</ol>
Reid Spencerd6a85b52007-05-14 16:14:57 +0000[diff] [blame]4971<p>In reverse mode, a similar computation is made except that the bits are
4972returned in the reverse order. So, for example, if <tt>X</tt> has the value
4973<tt>i16 0x0ACF (101011001111)</tt> and we apply
4974<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
4975<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4976</div>
4977
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]4978<div class="doc_subsubsection">
4979 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
4980</div>
4981
4982<div class="doc_text">
4983
4984<h5>Syntax:</h5>
4985<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
4986on any integer bit width.
4987<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4988 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
4989 declare i29 @llvm.part.set.i29.i9 (i29 %val, i9 %repl, i32 %lo, i32 %hi)
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]4990</pre>
4991
4992<h5>Overview:</h5>
4993<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
4994of bits in an integer value with another integer value. It returns the integer
4995with the replaced bits.</p>
4996
4997<h5>Arguments:</h5>
4998<p>The first argument, <tt>%val</tt> and the result may be integer types of
4999any bit width but they must have the same bit width. <tt>%val</tt> is the value
5000whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
5001integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
5002type since they specify only a bit index.</p>
5003
5004<h5>Semantics:</h5>
5005<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
5006of operation: forwards and reverse. If <tt>%lo</tt> is greater than
5007<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
5008operates in forward mode.</p>
5009<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
5010truncating it down to the size of the replacement area or zero extending it
5011up to that size.</p>
5012<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5013are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5014in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
5015to the <tt>%hi</tt>th bit.
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5016<p>In reverse mode, a similar computation is made except that the bits are
5017reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
5018<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5019<h5>Examples:</h5>
5020<pre>
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5021 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5022 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5023 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5024 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5025 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]5026</pre>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5027</div>
5028
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5029<!-- ======================================================================= -->
5030<div class="doc_subsection">
5031 <a name="int_debugger">Debugger Intrinsics</a>
5032</div>
5033
5034<div class="doc_text">
5035<p>
5036The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
5037are described in the <a
5038href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
5039Debugging</a> document.
5040</p>
5041</div>
5042
5043
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]5044<!-- ======================================================================= -->
5045<div class="doc_subsection">
5046 <a name="int_eh">Exception Handling Intrinsics</a>
5047</div>
5048
5049<div class="doc_text">
5050<p> The LLVM exception handling intrinsics (which all start with
5051<tt>llvm.eh.</tt> prefix), are described in the <a
5052href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
5053Handling</a> document. </p>
5054</div>
5055
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5056<!-- ======================================================================= -->
5057<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5058 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5059</div>
5060
5061<div class="doc_text">
5062<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5063 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5064 the <tt>nest</tt> attribute, from a function. The result is a callable
5065 function pointer lacking the nest parameter - the caller does not need
5066 to provide a value for it. Instead, the value to use is stored in
5067 advance in a "trampoline", a block of memory usually allocated
5068 on the stack, which also contains code to splice the nest value into the
5069 argument list. This is used to implement the GCC nested function address
5070 extension.
5071</p>
5072<p>
5073 For example, if the function is
5074 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
Bill Wendling03295ca2007-09-22 09:23:55 +0000[diff] [blame]5075 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as follows:</p>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5076<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5077 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
5078 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
5079 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
5080 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5081</pre>
Bill Wendling03295ca2007-09-22 09:23:55 +0000[diff] [blame]5082 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
5083 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5084</div>
5085
5086<!-- _______________________________________________________________________ -->
5087<div class="doc_subsubsection">
5088 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
5089</div>
5090<div class="doc_text">
5091<h5>Syntax:</h5>
5092<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5093declare 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]5094</pre>
5095<h5>Overview:</h5>
5096<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5097 This fills the memory pointed to by <tt>tramp</tt> with code
5098 and returns a function pointer suitable for executing it.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5099</p>
5100<h5>Arguments:</h5>
5101<p>
5102 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
5103 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
5104 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsc00c2ba2007-08-22 23:39:54 +0000[diff] [blame]5105 intrinsic. Note that the size and the alignment are target-specific - LLVM
5106 currently provides no portable way of determining them, so a front-end that
5107 generates this intrinsic needs to have some target-specific knowledge.
5108 The <tt>func</tt> argument must hold a function bitcast to an <tt>i8*</tt>.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5109</p>
5110<h5>Semantics:</h5>
5111<p>
5112 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5113 dependent code, turning it into a function. A pointer to this function is
5114 returned, but needs to be bitcast to an
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5115 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5116 before being called. The new function's signature is the same as that of
5117 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
5118 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
5119 of pointer type. Calling the new function is equivalent to calling
5120 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
5121 missing <tt>nest</tt> argument. If, after calling
5122 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
5123 modified, then the effect of any later call to the returned function pointer is
5124 undefined.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5125</p>
5126</div>
5127
5128<!-- ======================================================================= -->
5129<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5130 <a name="int_general">General Intrinsics</a>
5131</div>
5132
5133<div class="doc_text">
5134<p> This class of intrinsics is designed to be generic and has
5135no specific purpose. </p>
5136</div>
5137
5138<!-- _______________________________________________________________________ -->
5139<div class="doc_subsubsection">
5140 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
5141</div>
5142
5143<div class="doc_text">
5144
5145<h5>Syntax:</h5>
5146<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]5147 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]5148</pre>
5149
5150<h5>Overview:</h5>
5151
5152<p>
5153The '<tt>llvm.var.annotation</tt>' intrinsic
5154</p>
5155
5156<h5>Arguments:</h5>
5157
5158<p>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]5159The first argument is a pointer to a value, the second is a pointer to a
5160global string, the third is a pointer to a global string which is the source
5161file name, and the last argument is the line number.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5162</p>
5163
5164<h5>Semantics:</h5>
5165
5166<p>
5167This intrinsic allows annotation of local variables with arbitrary strings.
5168This can be useful for special purpose optimizations that want to look for these
5169 annotations. These have no other defined use, they are ignored by code
5170 generation and optimization.
5171</div>
5172
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5173<!-- _______________________________________________________________________ -->
5174<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]5175 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5176</div>
5177
5178<div class="doc_text">
5179
5180<h5>Syntax:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]5181<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
5182any integer bit width.
5183</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5184<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]5185 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5186 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5187 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5188 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5189 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]5190</pre>
5191
5192<h5>Overview:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]5193
5194<p>
5195The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5196</p>
5197
5198<h5>Arguments:</h5>
5199
5200<p>
5201The first argument is an integer value (result of some expression),
5202the second is a pointer to a global string, the third is a pointer to a global
5203string which is the source file name, and the last argument is the line number.
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]5204It returns the value of the first argument.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5205</p>
5206
5207<h5>Semantics:</h5>
5208
5209<p>
5210This intrinsic allows annotations to be put on arbitrary expressions
5211with arbitrary strings. This can be useful for special purpose optimizations
5212that want to look for these annotations. These have no other defined use, they
5213are ignored by code generation and optimization.
5214</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]5215
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5216<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5217<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]5218<address>
5219 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
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5223
5224 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]5225 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]5226 Last modified: $Date$
5227</address>
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