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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / b348d18caf834bc26a80e60aa7a2c9b1748734e8 / . / 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>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]29 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]30 <li><a href="#datalayout">Data Layout</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]31 </ol>
32 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]33 <li><a href="#typesystem">Type System</a>
34 <ol>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]35 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]36 <ol>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]37 <li><a href="#t_classifications">Type Classifications</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]38 </ol>
39 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]40 <li><a href="#t_derived">Derived Types</a>
41 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]42 <li><a href="#t_array">Array Type</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]43 <li><a href="#t_function">Function Type</a></li>
44 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]45 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]46 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]47 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]48 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]49 </ol>
50 </li>
51 </ol>
52 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]53 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]54 <ol>
55 <li><a href="#simpleconstants">Simple Constants</a>
56 <li><a href="#aggregateconstants">Aggregate Constants</a>
57 <li><a href="#globalconstants">Global Variable and Function Addresses</a>
58 <li><a href="#undefvalues">Undefined Values</a>
59 <li><a href="#constantexprs">Constant Expressions</a>
60 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]61 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]62 <li><a href="#othervalues">Other Values</a>
63 <ol>
64 <li><a href="#inlineasm">Inline Assembler Expressions</a>
65 </ol>
66 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]67 <li><a href="#instref">Instruction Reference</a>
68 <ol>
69 <li><a href="#terminators">Terminator Instructions</a>
70 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]71 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
72 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]73 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
74 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]75 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]76 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]77 </ol>
78 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]79 <li><a href="#binaryops">Binary Operations</a>
80 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]81 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
82 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
83 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]84 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
85 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
86 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]87 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
88 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
89 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]90 </ol>
91 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]92 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
93 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]94 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
95 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
96 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]97 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]98 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]99 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]100 </ol>
101 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]102 <li><a href="#vectorops">Vector Operations</a>
103 <ol>
104 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
105 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
106 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]107 </ol>
108 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]109 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]110 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]111 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
112 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
113 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]114 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
115 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
116 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]117 </ol>
118 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]119 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]120 <ol>
121 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
122 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
123 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
124 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
125 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]126 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
127 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
128 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
129 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]130 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
131 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]132 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]133 </ol>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]134 <li><a href="#otherops">Other Operations</a>
135 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]136 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
137 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]138 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]139 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]140 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]141 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]142 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]143 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]144 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]145 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]146 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]147 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]148 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
149 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]150 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
151 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
152 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]153 </ol>
154 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]155 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
156 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]157 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
158 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
159 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]160 </ol>
161 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]162 <li><a href="#int_codegen">Code Generator Intrinsics</a>
163 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]164 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
165 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
166 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
167 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
168 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
169 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
170 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]171 </ol>
172 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]173 <li><a href="#int_libc">Standard C Library Intrinsics</a>
174 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]175 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
176 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
177 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
178 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
179 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]180 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
181 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
182 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]183 </ol>
184 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]185 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]186 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]187 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]188 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
189 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
190 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]191 <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
192 <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]193 </ol>
194 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]195 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]196 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]197 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]198 <ol>
199 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]200 </ol>
201 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]202 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]203 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]204 <li><a href="#int_var_annotation">
Tanya Lattner91d0b882007-09-22 00:01:26 +0000[diff] [blame]205 <tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]206 </ol>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]207 <ol>
208 <li><a href="#int_annotation">
Tanya Lattner91d0b882007-09-22 00:01:26 +0000[diff] [blame]209 <tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]210 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]211 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]212 </ol>
213 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]214</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]215
216<div class="doc_author">
217 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
218 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]219</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]220
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]221<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]222<div class="doc_section"> <a name="abstract">Abstract </a></div>
223<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]224
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]225<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]226<p>This document is a reference manual for the LLVM assembly language.
227LLVM is an SSA based representation that provides type safety,
228low-level operations, flexibility, and the capability of representing
229'all' high-level languages cleanly. It is the common code
230representation used throughout all phases of the LLVM compilation
231strategy.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]232</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]233
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]234<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]235<div class="doc_section"> <a name="introduction">Introduction</a> </div>
236<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]237
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]238<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]239
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]240<p>The LLVM code representation is designed to be used in three
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]241different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]242representation (suitable for fast loading by a Just-In-Time compiler),
243and as a human readable assembly language representation. This allows
244LLVM to provide a powerful intermediate representation for efficient
245compiler transformations and analysis, while providing a natural means
246to debug and visualize the transformations. The three different forms
247of LLVM are all equivalent. This document describes the human readable
248representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]249
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]250<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]251while being expressive, typed, and extensible at the same time. It
252aims to be a "universal IR" of sorts, by being at a low enough level
253that high-level ideas may be cleanly mapped to it (similar to how
254microprocessors are "universal IR's", allowing many source languages to
255be mapped to them). By providing type information, LLVM can be used as
256the target of optimizations: for example, through pointer analysis, it
257can be proven that a C automatic variable is never accessed outside of
258the current function... allowing it to be promoted to a simple SSA
259value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]260
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]261</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]262
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]263<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]264<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]265
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]266<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]267
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]268<p>It is important to note that this document describes 'well formed'
269LLVM assembly language. There is a difference between what the parser
270accepts and what is considered 'well formed'. For example, the
271following instruction is syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]272
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]273<div class="doc_code">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]274<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]275%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]276</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]277</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]278
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]279<p>...because the definition of <tt>%x</tt> does not dominate all of
280its uses. The LLVM infrastructure provides a verification pass that may
281be used to verify that an LLVM module is well formed. This pass is
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]282automatically run by the parser after parsing input assembly and by
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]283the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]284by the verifier pass indicate bugs in transformation passes or input to
285the parser.</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]286</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]287
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]288<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]289
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]290<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]291<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]292<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]293
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]294<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]295
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]296 <p>LLVM identifiers come in two basic types: global and local. Global
297 identifiers (functions, global variables) begin with the @ character. Local
298 identifiers (register names, types) begin with the % character. Additionally,
299 there are three different formats for identifiers, for different purposes:
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]300
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]301<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]302 <li>Named values are represented as a string of characters with their prefix.
303 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
304 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]305 Identifiers which require other characters in their names can be surrounded
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]306 with quotes. In this way, anything except a <tt>&quot;</tt> character can
307 be used in a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]308
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]309 <li>Unnamed values are represented as an unsigned numeric value with their
310 prefix. For example, %12, @2, %44.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]311
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]312 <li>Constants, which are described in a <a href="#constants">section about
313 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]314</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]315
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]316<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]317don't need to worry about name clashes with reserved words, and the set of
318reserved words may be expanded in the future without penalty. Additionally,
319unnamed identifiers allow a compiler to quickly come up with a temporary
320variable without having to avoid symbol table conflicts.</p>
321
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]322<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]323languages. There are keywords for different opcodes
324('<tt><a href="#i_add">add</a></tt>',
325 '<tt><a href="#i_bitcast">bitcast</a></tt>',
326 '<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]327href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]328and others. These reserved words cannot conflict with variable names, because
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]329none of them start with a prefix character ('%' or '@').</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]330
331<p>Here is an example of LLVM code to multiply the integer variable
332'<tt>%X</tt>' by 8:</p>
333
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]334<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]335
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]336<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]337<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]338%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]339</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]340</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]341
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]342<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]343
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]344<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]345<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]346%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]347</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]348</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]349
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]350<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]351
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]352<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]353<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]354<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
355<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
356%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]357</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]358</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]359
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]360<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
361important lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]362
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]363<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]364
365 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
366 line.</li>
367
368 <li>Unnamed temporaries are created when the result of a computation is not
369 assigned to a named value.</li>
370
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]371 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]372
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]373</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]374
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]375<p>...and it also shows a convention that we follow in this document. When
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]376demonstrating instructions, we will follow an instruction with a comment that
377defines the type and name of value produced. Comments are shown in italic
378text.</p>
379
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]380</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]381
382<!-- *********************************************************************** -->
383<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
384<!-- *********************************************************************** -->
385
386<!-- ======================================================================= -->
387<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
388</div>
389
390<div class="doc_text">
391
392<p>LLVM programs are composed of "Module"s, each of which is a
393translation unit of the input programs. Each module consists of
394functions, global variables, and symbol table entries. Modules may be
395combined together with the LLVM linker, which merges function (and
396global variable) definitions, resolves forward declarations, and merges
397symbol table entries. Here is an example of the "hello world" module:</p>
398
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]399<div class="doc_code">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]400<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]401<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
402 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]403
404<i>; External declaration of the puts function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]405<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]406
407<i>; Definition of main function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]408define i32 @main() { <i>; i32()* </i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]409 <i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]410 %cast210 = <a
Chris Lattner6c0955b2007-06-12 17:01:15 +0000[diff] [blame]411 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]412
413 <i>; Call puts function to write out the string to stdout...</i>
414 <a
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]415 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]416 <a
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]417 href="#i_ret">ret</a> i32 0<br>}<br>
418</pre>
419</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]420
421<p>This example is made up of a <a href="#globalvars">global variable</a>
422named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
423function, and a <a href="#functionstructure">function definition</a>
424for "<tt>main</tt>".</p>
425
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]426<p>In general, a module is made up of a list of global values,
427where both functions and global variables are global values. Global values are
428represented by a pointer to a memory location (in this case, a pointer to an
429array of char, and a pointer to a function), and have one of the following <a
430href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]431
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]432</div>
433
434<!-- ======================================================================= -->
435<div class="doc_subsection">
436 <a name="linkage">Linkage Types</a>
437</div>
438
439<div class="doc_text">
440
441<p>
442All Global Variables and Functions have one of the following types of linkage:
443</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]444
445<dl>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]446
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]447 <dt><tt><b><a name="linkage_internal">internal</a></b></tt> </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]448
449 <dd>Global values with internal linkage are only directly accessible by
450 objects in the current module. In particular, linking code into a module with
451 an internal global value may cause the internal to be renamed as necessary to
452 avoid collisions. Because the symbol is internal to the module, all
453 references can be updated. This corresponds to the notion of the
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]454 '<tt>static</tt>' keyword in C.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]455 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]456
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]457 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]458
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]459 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
460 the same name when linkage occurs. This is typically used to implement
461 inline functions, templates, or other code which must be generated in each
462 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
463 allowed to be discarded.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]464 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]465
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]466 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]467
468 <dd>"<tt>weak</tt>" linkage is exactly the same as <tt>linkonce</tt> linkage,
469 except that unreferenced <tt>weak</tt> globals may not be discarded. This is
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]470 used for globals that may be emitted in multiple translation units, but that
471 are not guaranteed to be emitted into every translation unit that uses them.
472 One example of this are common globals in C, such as "<tt>int X;</tt>" at
473 global scope.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]474 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]475
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]476 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]477
478 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
479 pointer to array type. When two global variables with appending linkage are
480 linked together, the two global arrays are appended together. This is the
481 LLVM, typesafe, equivalent of having the system linker append together
482 "sections" with identical names when .o files are linked.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]483 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]484
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]485 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
486 <dd>The semantics of this linkage follow the ELF model: the symbol is weak
487 until linked, if not linked, the symbol becomes null instead of being an
488 undefined reference.
489 </dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]490
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]491 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]492
493 <dd>If none of the above identifiers are used, the global is externally
494 visible, meaning that it participates in linkage and can be used to resolve
495 external symbol references.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]496 </dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]497</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]498
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]499 <p>
500 The next two types of linkage are targeted for Microsoft Windows platform
501 only. They are designed to support importing (exporting) symbols from (to)
502 DLLs.
503 </p>
504
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]505 <dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]506 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
507
508 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
509 or variable via a global pointer to a pointer that is set up by the DLL
510 exporting the symbol. On Microsoft Windows targets, the pointer name is
511 formed by combining <code>_imp__</code> and the function or variable name.
512 </dd>
513
514 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
515
516 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
517 pointer to a pointer in a DLL, so that it can be referenced with the
518 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
519 name is formed by combining <code>_imp__</code> and the function or variable
520 name.
521 </dd>
522
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]523</dl>
524
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]525<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]526variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
527variable and was linked with this one, one of the two would be renamed,
528preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
529external (i.e., lacking any linkage declarations), they are accessible
Reid Spencerac8d2762007-01-05 00:59:10 +0000[diff] [blame]530outside of the current module.</p>
531<p>It is illegal for a function <i>declaration</i>
532to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]533or <tt>extern_weak</tt>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]534<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
535linkages.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]536</div>
537
538<!-- ======================================================================= -->
539<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]540 <a name="callingconv">Calling Conventions</a>
541</div>
542
543<div class="doc_text">
544
545<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
546and <a href="#i_invoke">invokes</a> can all have an optional calling convention
547specified for the call. The calling convention of any pair of dynamic
548caller/callee must match, or the behavior of the program is undefined. The
549following calling conventions are supported by LLVM, and more may be added in
550the future:</p>
551
552<dl>
553 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
554
555 <dd>This calling convention (the default if no other calling convention is
556 specified) matches the target C calling conventions. This calling convention
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]557 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencerc28d2bc2006-12-31 21:30:18 +0000[diff] [blame]558 prototype and implemented declaration of the function (as does normal C).
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]559 </dd>
560
561 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
562
563 <dd>This calling convention attempts to make calls as fast as possible
564 (e.g. by passing things in registers). This calling convention allows the
565 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattner8cdc5bc2005-05-06 23:08:23 +0000[diff] [blame]566 without having to conform to an externally specified ABI. Implementations of
567 this convention should allow arbitrary tail call optimization to be supported.
568 This calling convention does not support varargs and requires the prototype of
569 all callees to exactly match the prototype of the function definition.
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]570 </dd>
571
572 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
573
574 <dd>This calling convention attempts to make code in the caller as efficient
575 as possible under the assumption that the call is not commonly executed. As
576 such, these calls often preserve all registers so that the call does not break
577 any live ranges in the caller side. This calling convention does not support
578 varargs and requires the prototype of all callees to exactly match the
579 prototype of the function definition.
580 </dd>
581
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]582 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]583
584 <dd>Any calling convention may be specified by number, allowing
585 target-specific calling conventions to be used. Target specific calling
586 conventions start at 64.
587 </dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]588</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]589
590<p>More calling conventions can be added/defined on an as-needed basis, to
591support pascal conventions or any other well-known target-independent
592convention.</p>
593
594</div>
595
596<!-- ======================================================================= -->
597<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]598 <a name="visibility">Visibility Styles</a>
599</div>
600
601<div class="doc_text">
602
603<p>
604All Global Variables and Functions have one of the following visibility styles:
605</p>
606
607<dl>
608 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
609
610 <dd>On ELF, default visibility means that the declaration is visible to other
611 modules and, in shared libraries, means that the declared entity may be
612 overridden. On Darwin, default visibility means that the declaration is
613 visible to other modules. Default visibility corresponds to "external
614 linkage" in the language.
615 </dd>
616
617 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
618
619 <dd>Two declarations of an object with hidden visibility refer to the same
620 object if they are in the same shared object. Usually, hidden visibility
621 indicates that the symbol will not be placed into the dynamic symbol table,
622 so no other module (executable or shared library) can reference it
623 directly.
624 </dd>
625
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]626 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
627
628 <dd>On ELF, protected visibility indicates that the symbol will be placed in
629 the dynamic symbol table, but that references within the defining module will
630 bind to the local symbol. That is, the symbol cannot be overridden by another
631 module.
632 </dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]633</dl>
634
635</div>
636
637<!-- ======================================================================= -->
638<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]639 <a name="globalvars">Global Variables</a>
640</div>
641
642<div class="doc_text">
643
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]644<p>Global variables define regions of memory allocated at compilation time
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]645instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]646an explicit section to be placed in, and may have an optional explicit alignment
647specified. A variable may be defined as "thread_local", which means that it
648will not be shared by threads (each thread will have a separated copy of the
649variable). A variable may be defined as a global "constant," which indicates
650that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]651optimization, allowing the global data to be placed in the read-only section of
652an executable, etc). Note that variables that need runtime initialization
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]653cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]654
655<p>
656LLVM explicitly allows <em>declarations</em> of global variables to be marked
657constant, even if the final definition of the global is not. This capability
658can be used to enable slightly better optimization of the program, but requires
659the language definition to guarantee that optimizations based on the
660'constantness' are valid for the translation units that do not include the
661definition.
662</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]663
664<p>As SSA values, global variables define pointer values that are in
665scope (i.e. they dominate) all basic blocks in the program. Global
666variables always define a pointer to their "content" type because they
667describe a region of memory, and all memory objects in LLVM are
668accessed through pointers.</p>
669
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]670<p>LLVM allows an explicit section to be specified for globals. If the target
671supports it, it will emit globals to the section specified.</p>
672
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]673<p>An explicit alignment may be specified for a global. If not present, or if
674the alignment is set to zero, the alignment of the global is set by the target
675to whatever it feels convenient. If an explicit alignment is specified, the
676global is forced to have at least that much alignment. All alignments must be
677a power of 2.</p>
678
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]679<p>For example, the following defines a global with an initializer, section,
680 and alignment:</p>
681
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]682<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]683<pre>
Chris Lattner3e63a9d2007-07-13 20:01:46 +0000[diff] [blame]684@G = constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]685</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]686</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]687
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]688</div>
689
690
691<!-- ======================================================================= -->
692<div class="doc_subsection">
693 <a name="functionstructure">Functions</a>
694</div>
695
696<div class="doc_text">
697
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]698<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
699an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]700<a href="#visibility">visibility style</a>, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]701<a href="#callingconv">calling convention</a>, a return type, an optional
702<a href="#paramattrs">parameter attribute</a> for the return type, a function
703name, a (possibly empty) argument list (each with optional
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]704<a href="#paramattrs">parameter attributes</a>), an optional section, an
705optional alignment, an opening curly brace, a list of basic blocks, and a
706closing curly brace.
707
708LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
709optional <a href="#linkage">linkage type</a>, an optional
710<a href="#visibility">visibility style</a>, an optional
711<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]712<a href="#paramattrs">parameter attribute</a> for the return type, a function
713name, a possibly empty list of arguments, and an optional alignment.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]714
715<p>A function definition contains a list of basic blocks, forming the CFG for
716the function. Each basic block may optionally start with a label (giving the
717basic block a symbol table entry), contains a list of instructions, and ends
718with a <a href="#terminators">terminator</a> instruction (such as a branch or
719function return).</p>
720
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]721<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]722executed on entrance to the function, and it is not allowed to have predecessor
723basic blocks (i.e. there can not be any branches to the entry block of a
724function). Because the block can have no predecessors, it also cannot have any
725<a href="#i_phi">PHI nodes</a>.</p>
726
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]727<p>LLVM allows an explicit section to be specified for functions. If the target
728supports it, it will emit functions to the section specified.</p>
729
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]730<p>An explicit alignment may be specified for a function. If not present, or if
731the alignment is set to zero, the alignment of the function is set by the target
732to whatever it feels convenient. If an explicit alignment is specified, the
733function is forced to have at least that much alignment. All alignments must be
734a power of 2.</p>
735
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]736</div>
737
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]738
739<!-- ======================================================================= -->
740<div class="doc_subsection">
741 <a name="aliasstructure">Aliases</a>
742</div>
743<div class="doc_text">
744 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikova80e1182007-04-28 13:45:00 +0000[diff] [blame]745 function or global variable or bitcast of global value). Aliases may have an
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]746 optional <a href="#linkage">linkage type</a>, and an
747 optional <a href="#visibility">visibility style</a>.</p>
748
749 <h5>Syntax:</h5>
750
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]751<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]752<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]753@&lt;Name&gt; = [Linkage] [Visibility] alias &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]754</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]755</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]756
757</div>
758
759
760
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]761<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]762<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
763<div class="doc_text">
764 <p>The return type and each parameter of a function type may have a set of
765 <i>parameter attributes</i> associated with them. Parameter attributes are
766 used to communicate additional information about the result or parameters of
767 a function. Parameter attributes are considered to be part of the function
768 type so two functions types that differ only by the parameter attributes
769 are different function types.</p>
770
Reid Spencer950e9f82007-01-15 18:27:39 +0000[diff] [blame]771 <p>Parameter attributes are simple keywords that follow the type specified. If
772 multiple parameter attributes are needed, they are space separated. For
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]773 example:</p>
774
775<div class="doc_code">
776<pre>
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]777%someFunc = i16 (i8 signext %someParam) zeroext
778%someFunc = i16 (i8 zeroext %someParam) zeroext
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]779</pre>
780</div>
781
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]782 <p>Note that the two function types above are unique because the parameter has
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]783 a different attribute (<tt>signext</tt> in the first one, <tt>zeroext</tt> in
784 the second). Also note that the attribute for the function result
785 (<tt>zeroext</tt>) comes immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]786
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]787 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]788 <dl>
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]789 <dt><tt>zeroext</tt></dt>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]790 <dd>This indicates that the parameter should be zero extended just before
791 a call to this function.</dd>
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]792 <dt><tt>signext</tt></dt>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]793 <dd>This indicates that the parameter should be sign extended just before
794 a call to this function.</dd>
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]795 <dt><tt>inreg</tt></dt>
796 <dd>This indicates that the parameter should be placed in register (if
Anton Korobeynikov66a8c8c2007-01-28 15:27:21 +0000[diff] [blame]797 possible) during assembling function call. Support for this attribute is
798 target-specific</dd>
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]799 <dt><tt>sret</tt></dt>
Anton Korobeynikov66a8c8c2007-01-28 15:27:21 +0000[diff] [blame]800 <dd>This indicates that the parameter specifies the address of a structure
Reid Spencer67606122007-03-22 02:02:11 +0000[diff] [blame]801 that is the return value of the function in the source program.</dd>
Zhou Shengfebca342007-06-05 05:28:26 +0000[diff] [blame]802 <dt><tt>noalias</tt></dt>
803 <dd>This indicates that the parameter not alias any other object or any
804 other "noalias" objects during the function call.
Reid Spencer2dc52012007-03-22 02:18:56 +0000[diff] [blame]805 <dt><tt>noreturn</tt></dt>
806 <dd>This function attribute indicates that the function never returns. This
807 indicates to LLVM that every call to this function should be treated as if
808 an <tt>unreachable</tt> instruction immediately followed the call.</dd>
Reid Spencer67606122007-03-22 02:02:11 +0000[diff] [blame]809 <dt><tt>nounwind</tt></dt>
810 <dd>This function attribute indicates that the function type does not use
811 the unwind instruction and does not allow stack unwinding to propagate
812 through it.</dd>
Duncan Sands50f19f52007-07-27 19:57:41 +0000[diff] [blame]813 <dt><tt>nest</tt></dt>
814 <dd>This indicates that the parameter can be excised using the
815 <a href="#int_trampoline">trampoline intrinsics</a>.</dd>
Anton Korobeynikove925df72007-11-14 10:30:13 +0000[diff] [blame]816 <dt><tt>pure</tt></dt>
Duncan Sandsf04d5842007-11-14 21:14:02 +0000[diff] [blame]817 <dd>This function attribute indicates that the function has no side-effects
818 except for producing a return value. The value returned must only depend on
819 the function arguments and/or global variables. It may use values obtained
820 by dereferencing pointers.</dd>
Anton Korobeynikove925df72007-11-14 10:30:13 +0000[diff] [blame]821 <dt><tt>const</tt></dt>
Duncan Sandsf04d5842007-11-14 21:14:02 +0000[diff] [blame]822 <dd>A <tt>const</tt> function has the same restrictions as a <tt>pure</tt>
823 function, but in addition it is not allowed to dereference any pointer arguments
824 or global variables.
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]825 </dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]826
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]827</div>
828
829<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]830<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]831 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]832</div>
833
834<div class="doc_text">
835<p>
836Modules may contain "module-level inline asm" blocks, which corresponds to the
837GCC "file scope inline asm" blocks. These blocks are internally concatenated by
838LLVM and treated as a single unit, but may be separated in the .ll file if
839desired. The syntax is very simple:
840</p>
841
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]842<div class="doc_code">
843<pre>
844module asm "inline asm code goes here"
845module asm "more can go here"
846</pre>
847</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]848
849<p>The strings can contain any character by escaping non-printable characters.
850 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
851 for the number.
852</p>
853
854<p>
855 The inline asm code is simply printed to the machine code .s file when
856 assembly code is generated.
857</p>
858</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]859
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]860<!-- ======================================================================= -->
861<div class="doc_subsection">
862 <a name="datalayout">Data Layout</a>
863</div>
864
865<div class="doc_text">
866<p>A module may specify a target specific data layout string that specifies how
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]867data is to be laid out in memory. The syntax for the data layout is simply:</p>
868<pre> target datalayout = "<i>layout specification</i>"</pre>
869<p>The <i>layout specification</i> consists of a list of specifications
870separated by the minus sign character ('-'). Each specification starts with a
871letter and may include other information after the letter to define some
872aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]873<dl>
874 <dt><tt>E</tt></dt>
875 <dd>Specifies that the target lays out data in big-endian form. That is, the
876 bits with the most significance have the lowest address location.</dd>
877 <dt><tt>e</tt></dt>
878 <dd>Specifies that hte target lays out data in little-endian form. That is,
879 the bits with the least significance have the lowest address location.</dd>
880 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
881 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
882 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
883 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
884 too.</dd>
885 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
886 <dd>This specifies the alignment for an integer type of a given bit
887 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
888 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
889 <dd>This specifies the alignment for a vector type of a given bit
890 <i>size</i>.</dd>
891 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
892 <dd>This specifies the alignment for a floating point type of a given bit
893 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
894 (double).</dd>
895 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
896 <dd>This specifies the alignment for an aggregate type of a given bit
897 <i>size</i>.</dd>
898</dl>
899<p>When constructing the data layout for a given target, LLVM starts with a
900default set of specifications which are then (possibly) overriden by the
901specifications in the <tt>datalayout</tt> keyword. The default specifications
902are given in this list:</p>
903<ul>
904 <li><tt>E</tt> - big endian</li>
905 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
906 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
907 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
908 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
909 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
910 <li><tt>i64:32:64</tt> - i64 has abi alignment of 32-bits but preferred
911 alignment of 64-bits</li>
912 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
913 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
914 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
915 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
916 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
917</ul>
918<p>When llvm is determining the alignment for a given type, it uses the
919following rules:
920<ol>
921 <li>If the type sought is an exact match for one of the specifications, that
922 specification is used.</li>
923 <li>If no match is found, and the type sought is an integer type, then the
924 smallest integer type that is larger than the bitwidth of the sought type is
925 used. If none of the specifications are larger than the bitwidth then the the
926 largest integer type is used. For example, given the default specifications
927 above, the i7 type will use the alignment of i8 (next largest) while both
928 i65 and i256 will use the alignment of i64 (largest specified).</li>
929 <li>If no match is found, and the type sought is a vector type, then the
930 largest vector type that is smaller than the sought vector type will be used
931 as a fall back. This happens because <128 x double> can be implemented in
932 terms of 64 <2 x double>, for example.</li>
933</ol>
934</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]935
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]936<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]937<div class="doc_section"> <a name="typesystem">Type System</a> </div>
938<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]939
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]940<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]941
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]942<p>The LLVM type system is one of the most important features of the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]943intermediate representation. Being typed enables a number of
944optimizations to be performed on the IR directly, without having to do
945extra analyses on the side before the transformation. A strong type
946system makes it easier to read the generated code and enables novel
947analyses and transformations that are not feasible to perform on normal
948three address code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]949
950</div>
951
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]952<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]953<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]954<div class="doc_text">
John Criswell4457dc92004-04-09 16:48:45 +0000[diff] [blame]955<p>The primitive types are the fundamental building blocks of the LLVM
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]956system. The current set of primitive types is as follows:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]957
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]958<table class="layout">
959 <tr class="layout">
960 <td class="left">
961 <table>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]962 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]963 <tr><th>Type</th><th>Description</th></tr>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]964 <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]965 <tr><td><tt>label</tt></td><td>Branch destination</td></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]966 </tbody>
967 </table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]968 </td>
969 <td class="right">
970 <table>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]971 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]972 <tr><th>Type</th><th>Description</th></tr>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]973 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]974 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]975 </tbody>
976 </table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]977 </td>
978 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]979</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]980</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]981
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]982<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]983<div class="doc_subsubsection"> <a name="t_classifications">Type
984Classifications</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]985<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]986<p>These different primitive types fall into a few useful
987classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]988
989<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]990 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]991 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]992 <tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]993 <td><a name="t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]994 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]995 </tr>
996 <tr>
997 <td><a name="t_floating">floating point</a></td>
998 <td><tt>float, double</tt></td>
999 </tr>
1000 <tr>
1001 <td><a name="t_firstclass">first class</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1002 <td><tt>i1, ..., float, double, <br/>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1003 <a href="#t_pointer">pointer</a>,<a href="#t_vector">vector</a></tt>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1004 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1005 </tr>
1006 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1007</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1008
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1009<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1010most important. Values of these types are the only ones which can be
1011produced by instructions, passed as arguments, or used as operands to
1012instructions. This means that all structures and arrays must be
1013manipulated either by pointer or by component.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1014</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1015
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1016<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1017<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1018
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1019<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1020
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1021<p>The real power in LLVM comes from the derived types in the system.
1022This is what allows a programmer to represent arrays, functions,
1023pointers, and other useful types. Note that these derived types may be
1024recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1025
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1026</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1027
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1028<!-- _______________________________________________________________________ -->
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1029<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1030
1031<div class="doc_text">
1032
1033<h5>Overview:</h5>
1034<p>The integer type is a very simple derived type that simply specifies an
1035arbitrary bit width for the integer type desired. Any bit width from 1 bit to
10362^23-1 (about 8 million) can be specified.</p>
1037
1038<h5>Syntax:</h5>
1039
1040<pre>
1041 iN
1042</pre>
1043
1044<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1045value.</p>
1046
1047<h5>Examples:</h5>
1048<table class="layout">
1049 <tr class="layout">
1050 <td class="left">
1051 <tt>i1</tt><br/>
1052 <tt>i4</tt><br/>
1053 <tt>i8</tt><br/>
1054 <tt>i16</tt><br/>
1055 <tt>i32</tt><br/>
1056 <tt>i42</tt><br/>
1057 <tt>i64</tt><br/>
1058 <tt>i1942652</tt><br/>
1059 </td>
1060 <td class="left">
1061 A boolean integer of 1 bit<br/>
1062 A nibble sized integer of 4 bits.<br/>
1063 A byte sized integer of 8 bits.<br/>
1064 A half word sized integer of 16 bits.<br/>
1065 A word sized integer of 32 bits.<br/>
1066 An integer whose bit width is the answer. <br/>
1067 A double word sized integer of 64 bits.<br/>
1068 A really big integer of over 1 million bits.<br/>
1069 </td>
1070 </tr>
1071</table>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1072</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1073
1074<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1075<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1076
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1077<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1078
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1079<h5>Overview:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1080
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1081<p>The array type is a very simple derived type that arranges elements
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1082sequentially in memory. The array type requires a size (number of
1083elements) and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1084
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1085<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1086
1087<pre>
1088 [&lt;# elements&gt; x &lt;elementtype&gt;]
1089</pre>
1090
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1091<p>The number of elements is a constant integer value; elementtype may
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1092be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1093
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1094<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1095<table class="layout">
1096 <tr class="layout">
1097 <td class="left">
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1098 <tt>[40 x i32 ]</tt><br/>
1099 <tt>[41 x i32 ]</tt><br/>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1100 <tt>[40 x i8]</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1101 </td>
1102 <td class="left">
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1103 Array of 40 32-bit integer values.<br/>
1104 Array of 41 32-bit integer values.<br/>
1105 Array of 40 8-bit integer values.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1106 </td>
1107 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1108</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1109<p>Here are some examples of multidimensional arrays:</p>
1110<table class="layout">
1111 <tr class="layout">
1112 <td class="left">
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1113 <tt>[3 x [4 x i32]]</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1114 <tt>[12 x [10 x float]]</tt><br/>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1115 <tt>[2 x [3 x [4 x i16]]]</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1116 </td>
1117 <td class="left">
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1118 3x4 array of 32-bit integer values.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1119 12x10 array of single precision floating point values.<br/>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1120 2x3x4 array of 16-bit integer values.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1121 </td>
1122 </tr>
1123</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1124
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1125<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1126length array. Normally, accesses past the end of an array are undefined in
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1127LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1128As a special case, however, zero length arrays are recognized to be variable
1129length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1130type "{ i32, [0 x float]}", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1131
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1132</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1133
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1134<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1135<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1136<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1137<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1138<p>The function type can be thought of as a function signature. It
1139consists of a return type and a list of formal parameter types.
John Criswell009900b2003-11-25 21:45:46 +0000[diff] [blame]1140Function types are usually used to build virtual function tables
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1141(which are structures of pointers to functions), for indirect function
1142calls, and when defining a function.</p>
John Criswell009900b2003-11-25 21:45:46 +0000[diff] [blame]1143<p>
1144The return type of a function type cannot be an aggregate type.
1145</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1146<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1147<pre> &lt;returntype&gt; (&lt;parameter list&gt;)<br></pre>
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1148<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]1149specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1150which indicates that the function takes a variable number of arguments.
1151Variable argument functions can access their arguments with the <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1152 href="#int_varargs">variable argument handling intrinsic</a> functions.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1153<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1154<table class="layout">
1155 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1156 <td class="left"><tt>i32 (i32)</tt></td>
1157 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1158 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1159 </tr><tr class="layout">
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]1160 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1161 </tt></td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1162 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1163 an <tt>i16</tt> that should be sign extended and a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1164 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1165 <tt>float</tt>.
1166 </td>
1167 </tr><tr class="layout">
1168 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1169 <td class="left">A vararg function that takes at least one
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1170 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1171 which returns an integer. This is the signature for <tt>printf</tt> in
1172 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1173 </td>
1174 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1175</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1176
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1177</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1178<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1179<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1180<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1181<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1182<p>The structure type is used to represent a collection of data members
1183together in memory. The packing of the field types is defined to match
1184the ABI of the underlying processor. The elements of a structure may
1185be any type that has a size.</p>
1186<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1187and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1188field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1189instruction.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1190<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1191<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1192<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1193<table class="layout">
1194 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1195 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1196 <td class="left">A triple of three <tt>i32</tt> values</td>
1197 </tr><tr class="layout">
1198 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1199 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1200 second element is a <a href="#t_pointer">pointer</a> to a
1201 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1202 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1203 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1204</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1205</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1206
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1207<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1208<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1209</div>
1210<div class="doc_text">
1211<h5>Overview:</h5>
1212<p>The packed structure type is used to represent a collection of data members
1213together in memory. There is no padding between fields. Further, the alignment
1214of a packed structure is 1 byte. The elements of a packed structure may
1215be any type that has a size.</p>
1216<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1217and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1218field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1219instruction.</p>
1220<h5>Syntax:</h5>
1221<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1222<h5>Examples:</h5>
1223<table class="layout">
1224 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1225 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1226 <td class="left">A triple of three <tt>i32</tt> values</td>
1227 </tr><tr class="layout">
1228 <td class="left"><tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}&nbsp;&gt;</tt></td>
1229 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1230 second element is a <a href="#t_pointer">pointer</a> to a
1231 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1232 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1233 </tr>
1234</table>
1235</div>
1236
1237<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1238<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1239<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1240<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1241<p>As in many languages, the pointer type represents a pointer or
1242reference to another object, which must live in memory.</p>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1243<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1244<pre> &lt;type&gt; *<br></pre>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1245<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1246<table class="layout">
1247 <tr class="layout">
1248 <td class="left">
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1249 <tt>[4x i32]*</tt><br/>
1250 <tt>i32 (i32 *) *</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1251 </td>
1252 <td class="left">
1253 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]1254 four <tt>i32</tt> values<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1255 A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1256 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
1257 <tt>i32</tt>.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1258 </td>
1259 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1260</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1261</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1262
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1263<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1264<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1265<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1266
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1267<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1268
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1269<p>A vector type is a simple derived type that represents a vector
1270of elements. Vector types are used when multiple primitive data
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1271are operated in parallel using a single instruction (SIMD).
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1272A vector type requires a size (number of
Chris Lattnerb8d172f2005-11-10 01:44:22 +0000[diff] [blame]1273elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1274of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1275considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1276
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1277<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1278
1279<pre>
1280 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1281</pre>
1282
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1283<p>The number of elements is a constant integer value; elementtype may
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1284be any integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1285
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1286<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1287
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1288<table class="layout">
1289 <tr class="layout">
1290 <td class="left">
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1291 <tt>&lt;4 x i32&gt;</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1292 <tt>&lt;8 x float&gt;</tt><br/>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1293 <tt>&lt;2 x i64&gt;</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1294 </td>
1295 <td class="left">
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1296 Vector of 4 32-bit integer values.<br/>
1297 Vector of 8 floating-point values.<br/>
1298 Vector of 2 64-bit integer values.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1299 </td>
1300 </tr>
1301</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1302</div>
1303
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1304<!-- _______________________________________________________________________ -->
1305<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1306<div class="doc_text">
1307
1308<h5>Overview:</h5>
1309
1310<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksen8ac04ff2007-10-14 00:34:53 +0000[diff] [blame]1311corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1312In LLVM, opaque types can eventually be resolved to any type (not just a
1313structure type).</p>
1314
1315<h5>Syntax:</h5>
1316
1317<pre>
1318 opaque
1319</pre>
1320
1321<h5>Examples:</h5>
1322
1323<table class="layout">
1324 <tr class="layout">
1325 <td class="left">
1326 <tt>opaque</tt>
1327 </td>
1328 <td class="left">
1329 An opaque type.<br/>
1330 </td>
1331 </tr>
1332</table>
1333</div>
1334
1335
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1336<!-- *********************************************************************** -->
1337<div class="doc_section"> <a name="constants">Constants</a> </div>
1338<!-- *********************************************************************** -->
1339
1340<div class="doc_text">
1341
1342<p>LLVM has several different basic types of constants. This section describes
1343them all and their syntax.</p>
1344
1345</div>
1346
1347<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1348<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1349
1350<div class="doc_text">
1351
1352<dl>
1353 <dt><b>Boolean constants</b></dt>
1354
1355 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1356 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1357 </dd>
1358
1359 <dt><b>Integer constants</b></dt>
1360
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1361 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1362 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1363 integer types.
1364 </dd>
1365
1366 <dt><b>Floating point constants</b></dt>
1367
1368 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1369 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1370 notation (see below). Floating point constants must have a <a
1371 href="#t_floating">floating point</a> type. </dd>
1372
1373 <dt><b>Null pointer constants</b></dt>
1374
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1375 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1376 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1377
1378</dl>
1379
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1380<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1381of floating point constants. For example, the form '<tt>double
13820x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
13834.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1384(and the only time that they are generated by the disassembler) is when a
1385floating point constant must be emitted but it cannot be represented as a
1386decimal floating point number. For example, NaN's, infinities, and other
1387special values are represented in their IEEE hexadecimal format so that
1388assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1389
1390</div>
1391
1392<!-- ======================================================================= -->
1393<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1394</div>
1395
1396<div class="doc_text">
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]1397<p>Aggregate constants arise from aggregation of simple constants
1398and smaller aggregate constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1399
1400<dl>
1401 <dt><b>Structure constants</b></dt>
1402
1403 <dd>Structure constants are represented with notation similar to structure
1404 type definitions (a comma separated list of elements, surrounded by braces
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1405 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* %G }</tt>",
Chris Lattner3e63a9d2007-07-13 20:01:46 +0000[diff] [blame]1406 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]1407 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1408 types of elements must match those specified by the type.
1409 </dd>
1410
1411 <dt><b>Array constants</b></dt>
1412
1413 <dd>Array constants are represented with notation similar to array type
1414 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1415 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1416 constants must have <a href="#t_array">array type</a>, and the number and
1417 types of elements must match those specified by the type.
1418 </dd>
1419
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1420 <dt><b>Vector constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1421
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1422 <dd>Vector constants are represented with notation similar to vector type
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1423 definitions (a comma separated list of elements, surrounded by
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1424 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]1425 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1426 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1427 match those specified by the type.
1428 </dd>
1429
1430 <dt><b>Zero initialization</b></dt>
1431
1432 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1433 value to zero of <em>any</em> type, including scalar and aggregate types.
1434 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]1435 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1436 initializers.
1437 </dd>
1438</dl>
1439
1440</div>
1441
1442<!-- ======================================================================= -->
1443<div class="doc_subsection">
1444 <a name="globalconstants">Global Variable and Function Addresses</a>
1445</div>
1446
1447<div class="doc_text">
1448
1449<p>The addresses of <a href="#globalvars">global variables</a> and <a
1450href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1451constants. These constants are explicitly referenced when the <a
1452href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1453href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1454file:</p>
1455
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1456<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1457<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]1458@X = global i32 17
1459@Y = global i32 42
1460@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1461</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1462</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1463
1464</div>
1465
1466<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1467<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1468<div class="doc_text">
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1469 <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]1470 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1471 a constant is permitted.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1472
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1473 <p>Undefined values indicate to the compiler that the program is well defined
1474 no matter what value is used, giving the compiler more freedom to optimize.
1475 </p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1476</div>
1477
1478<!-- ======================================================================= -->
1479<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1480</div>
1481
1482<div class="doc_text">
1483
1484<p>Constant expressions are used to allow expressions involving other constants
1485to be used as constants. Constant expressions may be of any <a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1486href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1487that does not have side effects (e.g. load and call are not supported). The
1488following is the syntax for constant expressions:</p>
1489
1490<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1491 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1492 <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]1493 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1494
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1495 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1496 <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]1497 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]1498
1499 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1500 <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]1501 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]1502
1503 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1504 <dd>Truncate a floating point constant to another floating point type. The
1505 size of CST must be larger than the size of TYPE. Both types must be
1506 floating point.</dd>
1507
1508 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1509 <dd>Floating point extend a constant to another type. The size of CST must be
1510 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1511
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]1512 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1513 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame^]1514 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1515 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1516 of the same number of elements. If the value won't fit in the integer type,
1517 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1518
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1519 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1520 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame^]1521 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1522 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1523 of the same number of elements. If the value won't fit in the integer type,
1524 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1525
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1526 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1527 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame^]1528 constant. TYPE must be a scalar or vector floating point type. CST must be of
1529 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1530 of the same number of elements. If the value won't fit in the floating point
1531 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1532
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1533 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1534 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame^]1535 constant. TYPE must be a scalar or vector floating point type. CST must be of
1536 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1537 of the same number of elements. If the value won't fit in the floating point
1538 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1539
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1540 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1541 <dd>Convert a pointer typed constant to the corresponding integer constant
1542 TYPE must be an integer type. CST must be of pointer type. The CST value is
1543 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1544
1545 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1546 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1547 pointer type. CST must be of integer type. The CST value is zero extended,
1548 truncated, or unchanged to make it fit in a pointer size. This one is
1549 <i>really</i> dangerous!</dd>
1550
1551 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1552 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1553 identical (same number of bits). The conversion is done as if the CST value
1554 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]1555 with this operator, just the type. This can be used for conversion of
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1556 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]1557 pointers it is only valid to cast to another pointer type.
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1558 </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1559
1560 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1561
1562 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1563 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1564 instruction, the index list may have zero or more indexes, which are required
1565 to make sense for the type of "CSTPTR".</dd>
1566
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1567 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1568
1569 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1570 constants.</dd>
1571
1572 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1573 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1574
1575 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1576 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1577
1578 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1579
1580 <dd>Perform the <a href="#i_extractelement">extractelement
1581 operation</a> on constants.
1582
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1583 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1584
1585 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1586 operation</a> on constants.</dd>
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1587
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1588
1589 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1590
1591 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1592 operation</a> on constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1593
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1594 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1595
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1596 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1597 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1598 binary</a> operations. The constraints on operands are the same as those for
1599 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1600 values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1601</dl>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1602</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]1603
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1604<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1605<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1606<!-- *********************************************************************** -->
1607
1608<!-- ======================================================================= -->
1609<div class="doc_subsection">
1610<a name="inlineasm">Inline Assembler Expressions</a>
1611</div>
1612
1613<div class="doc_text">
1614
1615<p>
1616LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1617Module-Level Inline Assembly</a>) through the use of a special value. This
1618value represents the inline assembler as a string (containing the instructions
1619to emit), a list of operand constraints (stored as a string), and a flag that
1620indicates whether or not the inline asm expression has side effects. An example
1621inline assembler expression is:
1622</p>
1623
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1624<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1625<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1626i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1627</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1628</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1629
1630<p>
1631Inline assembler expressions may <b>only</b> be used as the callee operand of
1632a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
1633</p>
1634
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1635<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1636<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1637%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]1638</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1639</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1640
1641<p>
1642Inline asms with side effects not visible in the constraint list must be marked
1643as having side effects. This is done through the use of the
1644'<tt>sideeffect</tt>' keyword, like so:
1645</p>
1646
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1647<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1648<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1649call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1650</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1651</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1652
1653<p>TODO: The format of the asm and constraints string still need to be
1654documented here. Constraints on what can be done (e.g. duplication, moving, etc
1655need to be documented).
1656</p>
1657
1658</div>
1659
1660<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1661<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
1662<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1663
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1664<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1665
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1666<p>The LLVM instruction set consists of several different
1667classifications of instructions: <a href="#terminators">terminator
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1668instructions</a>, <a href="#binaryops">binary instructions</a>,
1669<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1670 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
1671instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1672
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1673</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1674
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1675<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1676<div class="doc_subsection"> <a name="terminators">Terminator
1677Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1678
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1679<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1680
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1681<p>As mentioned <a href="#functionstructure">previously</a>, every
1682basic block in a program ends with a "Terminator" instruction, which
1683indicates which block should be executed after the current block is
1684finished. These terminator instructions typically yield a '<tt>void</tt>'
1685value: they produce control flow, not values (the one exception being
1686the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1687<p>There are six different terminator instructions: the '<a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1688 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
1689instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1690the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
1691 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
1692 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1693
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1694</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1695
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1696<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1697<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
1698Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1699<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1700<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1701<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]1702 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1703</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1704<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1705<p>The '<tt>ret</tt>' instruction is used to return control flow (and a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1706value) from a function back to the caller.</p>
John Criswell4457dc92004-04-09 16:48:45 +0000[diff] [blame]1707<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1708returns a value and then causes control flow, and one that just causes
1709control flow to occur.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1710<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1711<p>The '<tt>ret</tt>' instruction may return any '<a
1712 href="#t_firstclass">first class</a>' type. Notice that a function is
1713not <a href="#wellformed">well formed</a> if there exists a '<tt>ret</tt>'
1714instruction inside of the function that returns a value that does not
1715match the return type of the function.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1716<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1717<p>When the '<tt>ret</tt>' instruction is executed, control flow
1718returns back to the calling function's context. If the caller is a "<a
John Criswellfa081872004-06-25 15:16:57 +0000[diff] [blame]1719 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1720the instruction after the call. If the caller was an "<a
1721 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1722at the beginning of the "normal" destination block. If the instruction
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1723returns a value, that value shall set the call or invoke instruction's
1724return value.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1725<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1726<pre> ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1727 ret void <i>; Return from a void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1728</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1729</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1730<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1731<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1732<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1733<h5>Syntax:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1734<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]1735</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1736<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1737<p>The '<tt>br</tt>' instruction is used to cause control flow to
1738transfer to a different basic block in the current function. There are
1739two forms of this instruction, corresponding to a conditional branch
1740and an unconditional branch.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1741<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1742<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1743single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1744unconditional form of the '<tt>br</tt>' instruction takes a single
1745'<tt>label</tt>' value as a target.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1746<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1747<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1748argument is evaluated. If the value is <tt>true</tt>, control flows
1749to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
1750control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1751<h5>Example:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1752<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]1753 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]1754</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1755<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1756<div class="doc_subsubsection">
1757 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
1758</div>
1759
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1760<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1761<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1762
1763<pre>
1764 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
1765</pre>
1766
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1767<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1768
1769<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
1770several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1771instruction, allowing a branch to occur to one of many possible
1772destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1773
1774
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1775<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1776
1777<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
1778comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
1779an array of pairs of comparison value constants and '<tt>label</tt>'s. The
1780table is not allowed to contain duplicate constant entries.</p>
1781
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1782<h5>Semantics:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1783
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1784<p>The <tt>switch</tt> instruction specifies a table of values and
1785destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]1786table is searched for the given value. If the value is found, control flow is
1787transfered to the corresponding destination; otherwise, control flow is
1788transfered to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1789
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1790<h5>Implementation:</h5>
1791
1792<p>Depending on properties of the target machine and the particular
1793<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]1794ways. For example, it could be generated as a series of chained conditional
1795branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1796
1797<h5>Example:</h5>
1798
1799<pre>
1800 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1801 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1802 switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1803
1804 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1805 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1806
1807 <i>; Implement a jump table:</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1808 switch i32 %val, label %otherwise [ i32 0, label %onzero
1809 i32 1, label %onone
1810 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1811</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1812</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1813
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1814<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1815<div class="doc_subsubsection">
1816 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
1817</div>
1818
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1819<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1820
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1821<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1822
1823<pre>
1824 &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]1825 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1826</pre>
1827
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]1828<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1829
1830<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
1831function, with the possibility of control flow transfer to either the
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1832'<tt>normal</tt>' label or the
1833'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1834"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
1835"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1836href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
1837continued at the dynamically nearest "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1838
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1839<h5>Arguments:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1840
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1841<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1842
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1843<ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1844 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]1845 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1846 convention</a> the call should use. If none is specified, the call defaults
1847 to using C calling conventions.
1848 </li>
1849 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
1850 function value being invoked. In most cases, this is a direct function
1851 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
1852 an arbitrary pointer to function value.
1853 </li>
1854
1855 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
1856 function to be invoked. </li>
1857
1858 <li>'<tt>function args</tt>': argument list whose types match the function
1859 signature argument types. If the function signature indicates the function
1860 accepts a variable number of arguments, the extra arguments can be
1861 specified. </li>
1862
1863 <li>'<tt>normal label</tt>': the label reached when the called function
1864 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
1865
1866 <li>'<tt>exception label</tt>': the label reached when a callee returns with
1867 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
1868
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1869</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1870
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1871<h5>Semantics:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1872
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1873<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1874href="#i_call">call</a></tt>' instruction in most regards. The primary
1875difference is that it establishes an association with a label, which is used by
1876the runtime library to unwind the stack.</p>
1877
1878<p>This instruction is used in languages with destructors to ensure that proper
1879cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
1880exception. Additionally, this is important for implementation of
1881'<tt>catch</tt>' clauses in high-level languages that support them.</p>
1882
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1883<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1884<pre>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1885 %retval = invoke i32 %Test(i32 15) to label %Continue
1886 unwind label %TestCleanup <i>; {i32}:retval set</i>
1887 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Test(i32 15) to label %Continue
1888 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1889</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1890</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1891
1892
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1893<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1894
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1895<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
1896Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1897
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1898<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1899
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1900<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1901<pre>
1902 unwind
1903</pre>
1904
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1905<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1906
1907<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
1908at the first callee in the dynamic call stack which used an <a
1909href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
1910primarily used to implement exception handling.</p>
1911
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1912<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1913
1914<p>The '<tt>unwind</tt>' intrinsic causes execution of the current function to
1915immediately halt. The dynamic call stack is then searched for the first <a
1916href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
1917execution continues at the "exceptional" destination block specified by the
1918<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
1919dynamic call chain, undefined behavior results.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1920</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1921
1922<!-- _______________________________________________________________________ -->
1923
1924<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
1925Instruction</a> </div>
1926
1927<div class="doc_text">
1928
1929<h5>Syntax:</h5>
1930<pre>
1931 unreachable
1932</pre>
1933
1934<h5>Overview:</h5>
1935
1936<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
1937instruction is used to inform the optimizer that a particular portion of the
1938code is not reachable. This can be used to indicate that the code after a
1939no-return function cannot be reached, and other facts.</p>
1940
1941<h5>Semantics:</h5>
1942
1943<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
1944</div>
1945
1946
1947
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1948<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1949<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1950<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1951<p>Binary operators are used to do most of the computation in a
1952program. They require two operands, execute an operation on them, and
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1953produce a single value. The operands might represent
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1954multiple 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]1955The result value of a binary operator is not
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1956necessarily the same type as its operands.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1957<p>There are several different binary operators:</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1958</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1959<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1960<div class="doc_subsubsection"> <a name="i_add">'<tt>add</tt>'
1961Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1962<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1963<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1964<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]1965</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1966<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1967<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1968<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1969<p>The two arguments to the '<tt>add</tt>' instruction must be either <a
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1970 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a> values.
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1971 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]1972Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1973<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1974<p>The value produced is the integer or floating point sum of the two
1975operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1976<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1977<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]1978</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1979</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1980<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1981<div class="doc_subsubsection"> <a name="i_sub">'<tt>sub</tt>'
1982Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1983<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1984<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1985<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]1986</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1987<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1988<p>The '<tt>sub</tt>' instruction returns the difference of its two
1989operands.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1990<p>Note that the '<tt>sub</tt>' instruction is used to represent the '<tt>neg</tt>'
1991instruction present in most other intermediate representations.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1992<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1993<p>The two arguments to the '<tt>sub</tt>' instruction must be either <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1994 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1995values.
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1996This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1997Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1998<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1999<p>The value produced is the integer or floating point difference of
2000the two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2001<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2002<pre>
2003 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2004 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2005</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2006</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2007<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2008<div class="doc_subsubsection"> <a name="i_mul">'<tt>mul</tt>'
2009Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2010<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2011<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2012<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]2013</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2014<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2015<p>The '<tt>mul</tt>' instruction returns the product of its two
2016operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2017<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2018<p>The two arguments to the '<tt>mul</tt>' instruction must be either <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2019 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2020values.
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2021This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2022Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2023<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2024<p>The value produced is the integer or floating point product of the
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2025two operands.</p>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]2026<p>Because the operands are the same width, the result of an integer
2027multiplication is the same whether the operands should be deemed unsigned or
2028signed.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2029<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2030<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]2031</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2032</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2033<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2034<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2035</a></div>
2036<div class="doc_text">
2037<h5>Syntax:</h5>
2038<pre> &lt;result&gt; = udiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2039</pre>
2040<h5>Overview:</h5>
2041<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2042operands.</p>
2043<h5>Arguments:</h5>
2044<p>The two arguments to the '<tt>udiv</tt>' instruction must be
2045<a href="#t_integer">integer</a> values. Both arguments must have identical
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2046types. This instruction can also take <a href="#t_vector">vector</a> versions
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2047of the values in which case the elements must be integers.</p>
2048<h5>Semantics:</h5>
2049<p>The value produced is the unsigned integer quotient of the two operands. This
2050instruction always performs an unsigned division operation, regardless of
2051whether the arguments are unsigned or not.</p>
2052<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2053<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]2054</pre>
2055</div>
2056<!-- _______________________________________________________________________ -->
2057<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2058</a> </div>
2059<div class="doc_text">
2060<h5>Syntax:</h5>
2061<pre> &lt;result&gt; = sdiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2062</pre>
2063<h5>Overview:</h5>
2064<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2065operands.</p>
2066<h5>Arguments:</h5>
2067<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2068<a href="#t_integer">integer</a> values. Both arguments must have identical
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2069types. This instruction can also take <a href="#t_vector">vector</a> versions
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2070of the values in which case the elements must be integers.</p>
2071<h5>Semantics:</h5>
2072<p>The value produced is the signed integer quotient of the two operands. This
2073instruction always performs a signed division operation, regardless of whether
2074the arguments are signed or not.</p>
2075<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2076<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]2077</pre>
2078</div>
2079<!-- _______________________________________________________________________ -->
2080<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2081Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2082<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2083<h5>Syntax:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2084<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]2085</pre>
2086<h5>Overview:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2087<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2088operands.</p>
2089<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2090<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2091<a href="#t_floating">floating point</a> values. Both arguments must have
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2092identical types. This instruction can also take <a href="#t_vector">vector</a>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2093versions of floating point values.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2094<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2095<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2096<h5>Example:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2097<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]2098</pre>
2099</div>
2100<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2101<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2102</div>
2103<div class="doc_text">
2104<h5>Syntax:</h5>
2105<pre> &lt;result&gt; = urem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2106</pre>
2107<h5>Overview:</h5>
2108<p>The '<tt>urem</tt>' instruction returns the remainder from the
2109unsigned division of its two arguments.</p>
2110<h5>Arguments:</h5>
2111<p>The two arguments to the '<tt>urem</tt>' instruction must be
2112<a href="#t_integer">integer</a> values. Both arguments must have identical
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2113types. This instruction can also take <a href="#t_vector">vector</a> versions
2114of the values in which case the elements must be integers.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2115<h5>Semantics:</h5>
2116<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
2117This instruction always performs an unsigned division to get the remainder,
2118regardless of whether the arguments are unsigned or not.</p>
2119<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2120<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]2121</pre>
2122
2123</div>
2124<!-- _______________________________________________________________________ -->
2125<div class="doc_subsubsection"> <a name="i_srem">'<tt>srem</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2126Instruction</a> </div>
2127<div class="doc_text">
2128<h5>Syntax:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2129<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]2130</pre>
2131<h5>Overview:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2132<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2133signed division of its two operands. This instruction can also take
2134<a href="#t_vector">vector</a> versions of the values in which case
2135the elements must be integers.</p>
2136</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2137<h5>Arguments:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2138<p>The two arguments to the '<tt>srem</tt>' instruction must be
2139<a href="#t_integer">integer</a> values. Both arguments must have identical
2140types.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2141<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2142<p>This instruction returns the <i>remainder</i> of a division (where the result
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2143has the same sign as the dividend, <tt>var1</tt>), not the <i>modulo</i>
2144operator (where the result has the same sign as the divisor, <tt>var2</tt>) of
2145a value. For more information about the difference, see <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2146 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2147Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencer64f5c6c2007-03-24 22:40:44 +0000[diff] [blame]2148please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2149Wikipedia: modulo operation</a>.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2150<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2151<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]2152</pre>
2153
2154</div>
2155<!-- _______________________________________________________________________ -->
2156<div class="doc_subsubsection"> <a name="i_frem">'<tt>frem</tt>'
2157Instruction</a> </div>
2158<div class="doc_text">
2159<h5>Syntax:</h5>
2160<pre> &lt;result&gt; = frem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2161</pre>
2162<h5>Overview:</h5>
2163<p>The '<tt>frem</tt>' instruction returns the remainder from the
2164division of its two operands.</p>
2165<h5>Arguments:</h5>
2166<p>The two arguments to the '<tt>frem</tt>' instruction must be
2167<a href="#t_floating">floating point</a> values. Both arguments must have
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2168identical types. This instruction can also take <a href="#t_vector">vector</a>
2169versions of floating point values.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2170<h5>Semantics:</h5>
2171<p>This instruction returns the <i>remainder</i> of a division.</p>
2172<h5>Example:</h5>
2173<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]2174</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2175</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]2176
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2177<!-- ======================================================================= -->
2178<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2179Operations</a> </div>
2180<div class="doc_text">
2181<p>Bitwise binary operators are used to do various forms of
2182bit-twiddling in a program. They are generally very efficient
2183instructions and can commonly be strength reduced from other
2184instructions. They require two operands, execute an operation on them,
2185and produce a single value. The resulting value of the bitwise binary
2186operators is always the same type as its first operand.</p>
2187</div>
2188
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2189<!-- _______________________________________________________________________ -->
2190<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2191Instruction</a> </div>
2192<div class="doc_text">
2193<h5>Syntax:</h5>
2194<pre> &lt;result&gt; = shl &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2195</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2196
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2197<h5>Overview:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2198
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2199<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2200the left a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2201
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2202<h5>Arguments:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2203
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2204<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
2205 href="#t_integer">integer</a> type.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2206
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2207<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2208
2209<p>The value produced is <tt>var1</tt> * 2<sup><tt>var2</tt></sup>. If
2210<tt>var2</tt> is (statically or dynamically) equal to or larger than the number
2211of bits in <tt>var1</tt>, the result is undefined.</p>
2212
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2213<h5>Example:</h5><pre>
2214 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2215 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2216 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2217 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2218</pre>
2219</div>
2220<!-- _______________________________________________________________________ -->
2221<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2222Instruction</a> </div>
2223<div class="doc_text">
2224<h5>Syntax:</h5>
2225<pre> &lt;result&gt; = lshr &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2226</pre>
2227
2228<h5>Overview:</h5>
2229<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2230operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2231
2232<h5>Arguments:</h5>
2233<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
2234<a href="#t_integer">integer</a> type.</p>
2235
2236<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2237
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2238<p>This instruction always performs a logical shift right operation. The most
2239significant bits of the result will be filled with zero bits after the
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2240shift. If <tt>var2</tt> is (statically or dynamically) equal to or larger than
2241the number of bits in <tt>var1</tt>, the result is undefined.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2242
2243<h5>Example:</h5>
2244<pre>
2245 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2246 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2247 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2248 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2249 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2250</pre>
2251</div>
2252
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2253<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2254<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2255Instruction</a> </div>
2256<div class="doc_text">
2257
2258<h5>Syntax:</h5>
2259<pre> &lt;result&gt; = ashr &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2260</pre>
2261
2262<h5>Overview:</h5>
2263<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2264operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2265
2266<h5>Arguments:</h5>
2267<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
2268<a href="#t_integer">integer</a> type.</p>
2269
2270<h5>Semantics:</h5>
2271<p>This instruction always performs an arithmetic shift right operation,
2272The most significant bits of the result will be filled with the sign bit
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2273of <tt>var1</tt>. If <tt>var2</tt> is (statically or dynamically) equal to or
2274larger than the number of bits in <tt>var1</tt>, the result is undefined.
2275</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2276
2277<h5>Example:</h5>
2278<pre>
2279 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2280 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2281 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2282 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2283 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2284</pre>
2285</div>
2286
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2287<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2288<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2289Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2290<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2291<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2292<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]2293</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2294<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2295<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2296its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2297<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2298<p>The two arguments to the '<tt>and</tt>' instruction must be <a
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]2299 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2300identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2301<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2302<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2303<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2304<div style="align: center">
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2305<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2306 <tbody>
2307 <tr>
2308 <td>In0</td>
2309 <td>In1</td>
2310 <td>Out</td>
2311 </tr>
2312 <tr>
2313 <td>0</td>
2314 <td>0</td>
2315 <td>0</td>
2316 </tr>
2317 <tr>
2318 <td>0</td>
2319 <td>1</td>
2320 <td>0</td>
2321 </tr>
2322 <tr>
2323 <td>1</td>
2324 <td>0</td>
2325 <td>0</td>
2326 </tr>
2327 <tr>
2328 <td>1</td>
2329 <td>1</td>
2330 <td>1</td>
2331 </tr>
2332 </tbody>
2333</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2334</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2335<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2336<pre> &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
2337 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2338 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2339</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2340</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2341<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2342<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2343<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2344<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2345<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]2346</pre>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2347<h5>Overview:</h5>
2348<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2349or of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2350<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2351<p>The two arguments to the '<tt>or</tt>' instruction must be <a
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]2352 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2353identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2354<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2355<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2356<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2357<div style="align: center">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2358<table border="1" cellspacing="0" cellpadding="4">
2359 <tbody>
2360 <tr>
2361 <td>In0</td>
2362 <td>In1</td>
2363 <td>Out</td>
2364 </tr>
2365 <tr>
2366 <td>0</td>
2367 <td>0</td>
2368 <td>0</td>
2369 </tr>
2370 <tr>
2371 <td>0</td>
2372 <td>1</td>
2373 <td>1</td>
2374 </tr>
2375 <tr>
2376 <td>1</td>
2377 <td>0</td>
2378 <td>1</td>
2379 </tr>
2380 <tr>
2381 <td>1</td>
2382 <td>1</td>
2383 <td>1</td>
2384 </tr>
2385 </tbody>
2386</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2387</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2388<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2389<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2390 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2391 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2392</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2393</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2394<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2395<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2396Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2397<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2398<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2399<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]2400</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2401<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2402<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2403or of its two operands. The <tt>xor</tt> is used to implement the
2404"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2405<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2406<p>The two arguments to the '<tt>xor</tt>' instruction must be <a
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]2407 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2408identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2409<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2410<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2411<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2412<div style="align: center">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2413<table border="1" cellspacing="0" cellpadding="4">
2414 <tbody>
2415 <tr>
2416 <td>In0</td>
2417 <td>In1</td>
2418 <td>Out</td>
2419 </tr>
2420 <tr>
2421 <td>0</td>
2422 <td>0</td>
2423 <td>0</td>
2424 </tr>
2425 <tr>
2426 <td>0</td>
2427 <td>1</td>
2428 <td>1</td>
2429 </tr>
2430 <tr>
2431 <td>1</td>
2432 <td>0</td>
2433 <td>1</td>
2434 </tr>
2435 <tr>
2436 <td>1</td>
2437 <td>1</td>
2438 <td>0</td>
2439 </tr>
2440 </tbody>
2441</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2442</div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2443<p> </p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2444<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2445<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2446 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2447 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2448 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2449</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2450</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2451
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2452<!-- ======================================================================= -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2453<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2454 <a name="vectorops">Vector Operations</a>
2455</div>
2456
2457<div class="doc_text">
2458
2459<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2460target-independent manner. These instructions cover the element-access and
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2461vector-specific operations needed to process vectors effectively. While LLVM
2462does directly support these vector operations, many sophisticated algorithms
2463will want to use target-specific intrinsics to take full advantage of a specific
2464target.</p>
2465
2466</div>
2467
2468<!-- _______________________________________________________________________ -->
2469<div class="doc_subsubsection">
2470 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
2471</div>
2472
2473<div class="doc_text">
2474
2475<h5>Syntax:</h5>
2476
2477<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2478 &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]2479</pre>
2480
2481<h5>Overview:</h5>
2482
2483<p>
2484The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2485element from a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2486</p>
2487
2488
2489<h5>Arguments:</h5>
2490
2491<p>
2492The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2493value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2494an index indicating the position from which to extract the element.
2495The index may be a variable.</p>
2496
2497<h5>Semantics:</h5>
2498
2499<p>
2500The result is a scalar of the same type as the element type of
2501<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
2502<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
2503results are undefined.
2504</p>
2505
2506<h5>Example:</h5>
2507
2508<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2509 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2510</pre>
2511</div>
2512
2513
2514<!-- _______________________________________________________________________ -->
2515<div class="doc_subsubsection">
2516 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
2517</div>
2518
2519<div class="doc_text">
2520
2521<h5>Syntax:</h5>
2522
2523<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2524 &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]2525</pre>
2526
2527<h5>Overview:</h5>
2528
2529<p>
2530The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2531element into a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2532</p>
2533
2534
2535<h5>Arguments:</h5>
2536
2537<p>
2538The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2539value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2540scalar value whose type must equal the element type of the first
2541operand. The third operand is an index indicating the position at
2542which to insert the value. The index may be a variable.</p>
2543
2544<h5>Semantics:</h5>
2545
2546<p>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2547The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2548element values are those of <tt>val</tt> except at position
2549<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
2550exceeds the length of <tt>val</tt>, the results are undefined.
2551</p>
2552
2553<h5>Example:</h5>
2554
2555<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2556 %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]2557</pre>
2558</div>
2559
2560<!-- _______________________________________________________________________ -->
2561<div class="doc_subsubsection">
2562 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
2563</div>
2564
2565<div class="doc_text">
2566
2567<h5>Syntax:</h5>
2568
2569<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2570 &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]2571</pre>
2572
2573<h5>Overview:</h5>
2574
2575<p>
2576The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
2577from two input vectors, returning a vector of the same type.
2578</p>
2579
2580<h5>Arguments:</h5>
2581
2582<p>
2583The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
2584with types that match each other and types that match the result of the
2585instruction. The third argument is a shuffle mask, which has the same number
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2586of elements as the other vector type, but whose element type is always 'i32'.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2587</p>
2588
2589<p>
2590The shuffle mask operand is required to be a constant vector with either
2591constant integer or undef values.
2592</p>
2593
2594<h5>Semantics:</h5>
2595
2596<p>
2597The elements of the two input vectors are numbered from left to right across
2598both of the vectors. The shuffle mask operand specifies, for each element of
2599the result vector, which element of the two input registers the result element
2600gets. The element selector may be undef (meaning "don't care") and the second
2601operand may be undef if performing a shuffle from only one vector.
2602</p>
2603
2604<h5>Example:</h5>
2605
2606<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2607 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2608 &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]2609 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
2610 &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]2611</pre>
2612</div>
2613
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]2614
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2615<!-- ======================================================================= -->
2616<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]2617 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2618</div>
2619
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2620<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2621
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2622<p>A key design point of an SSA-based representation is how it
2623represents memory. In LLVM, no memory locations are in SSA form, which
2624makes things very simple. This section describes how to read, write,
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2625allocate, and free memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2626
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2627</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2628
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2629<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2630<div class="doc_subsubsection">
2631 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
2632</div>
2633
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2634<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2635
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2636<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2637
2638<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2639 &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]2640</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2641
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2642<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2643
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2644<p>The '<tt>malloc</tt>' instruction allocates memory from the system
2645heap and returns a pointer to it.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2646
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2647<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2648
2649<p>The '<tt>malloc</tt>' instruction allocates
2650<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswell6e4ca612004-02-24 16:13:56 +0000[diff] [blame]2651bytes of memory from the operating system and returns a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2652appropriate type to the program. If "NumElements" is specified, it is the
2653number of elements allocated. If an alignment is specified, the value result
2654of the allocation is guaranteed to be aligned to at least that boundary. If
2655not specified, or if zero, the target can choose to align the allocation on any
2656convenient boundary.</p>
2657
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2658<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2659
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2660<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2661
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2662<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
2663a pointer is returned.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2664
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2665<h5>Example:</h5>
2666
2667<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2668 %array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2669
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2670 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
2671 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
2672 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
2673 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
2674 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2675</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2676</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2677
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2678<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2679<div class="doc_subsubsection">
2680 <a name="i_free">'<tt>free</tt>' Instruction</a>
2681</div>
2682
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2683<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2684
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2685<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2686
2687<pre>
2688 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2689</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2690
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2691<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2692
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2693<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2694memory heap to be reallocated in the future.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2695
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2696<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2697
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2698<p>'<tt>value</tt>' shall be a pointer value that points to a value
2699that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
2700instruction.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2701
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2702<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2703
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2704<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2705after this instruction executes.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2706
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2707<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2708
2709<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2710 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
2711 free [4 x i8]* %array
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2712</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2713</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2714
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2715<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2716<div class="doc_subsubsection">
2717 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
2718</div>
2719
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2720<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2721
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2722<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2723
2724<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2725 &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]2726</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2727
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2728<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2729
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2730<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
2731currently executing function, to be automatically released when this function
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2732returns to its caller.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2733
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2734<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2735
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2736<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2737bytes of memory on the runtime stack, returning a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2738appropriate type to the program. If "NumElements" is specified, it is the
2739number of elements allocated. If an alignment is specified, the value result
2740of the allocation is guaranteed to be aligned to at least that boundary. If
2741not specified, or if zero, the target can choose to align the allocation on any
2742convenient boundary.</p>
2743
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2744<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2745
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2746<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2747
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2748<p>Memory is allocated; a pointer is returned. '<tt>alloca</tt>'d
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2749memory is automatically released when the function returns. The '<tt>alloca</tt>'
2750instruction is commonly used to represent automatic variables that must
2751have an address available. When the function returns (either with the <tt><a
John Criswelldae2e932005-05-12 16:55:34 +0000[diff] [blame]2752 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]2753instructions), the memory is reclaimed.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2754
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2755<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2756
2757<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2758 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2759 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
2760 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2761 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2762</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2763</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2764
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2765<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2766<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
2767Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2768<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2769<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]2770<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]2771<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2772<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2773<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2774<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]2775address from which to load. The pointer must point to a <a
Chris Lattnere53e5082004-06-03 22:57:15 +0000[diff] [blame]2776 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]2777marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2778the number or order of execution of this <tt>load</tt> with other
2779volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
2780instructions. </p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2781<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2782<p>The location of memory pointed to is loaded.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2783<h5>Examples:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2784<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2785 <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2786 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
2787 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2788</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2789</div>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2790<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2791<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
2792Instruction</a> </div>
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]2793<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2794<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]2795<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
2796 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]2797</pre>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2798<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2799<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2800<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2801<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2802to 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]2803operand must be a pointer to the type of the '<tt>&lt;value&gt;</tt>'
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2804operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2805optimizer is not allowed to modify the number or order of execution of
2806this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
2807 href="#i_store">store</a></tt> instructions.</p>
2808<h5>Semantics:</h5>
2809<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
2810at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2811<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2812<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]2813 store i32 3, i32* %ptr <i>; yields {void}</i>
2814 %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]2815</pre>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]2816</div>
2817
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2818<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2819<div class="doc_subsubsection">
2820 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
2821</div>
2822
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2823<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2824<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2825<pre>
2826 &lt;result&gt; = getelementptr &lt;ty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
2827</pre>
2828
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2829<h5>Overview:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2830
2831<p>
2832The '<tt>getelementptr</tt>' instruction is used to get the address of a
2833subelement of an aggregate data structure.</p>
2834
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2835<h5>Arguments:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2836
Reid Spencer85f5b5b2006-12-04 21:29:24 +0000[diff] [blame]2837<p>This instruction takes a list of integer operands that indicate what
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2838elements of the aggregate object to index to. The actual types of the arguments
2839provided depend on the type of the first pointer argument. The
2840'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]2841levels 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]2842structure, only <tt>i32</tt> integer constants are allowed. When indexing
Reid Spencer85f5b5b2006-12-04 21:29:24 +0000[diff] [blame]2843into an array or pointer, only integers of 32 or 64 bits are allowed, and will
2844be sign extended to 64-bit values.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2845
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2846<p>For example, let's consider a C code fragment and how it gets
2847compiled to LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2848
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2849<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2850<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2851struct RT {
2852 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]2853 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2854 char C;
2855};
2856struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]2857 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2858 double Y;
2859 struct RT Z;
2860};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2861
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]2862int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2863 return &amp;s[1].Z.B[5][13];
2864}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2865</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2866</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2867
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2868<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2869
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2870<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2871<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2872%RT = type { i8 , [10 x [20 x i32]], i8 }
2873%ST = type { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2874
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2875define i32* %foo(%ST* %s) {
2876entry:
2877 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
2878 ret i32* %reg
2879}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2880</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2881</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2882
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2883<h5>Semantics:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2884
2885<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2886on the pointer type that is being indexed into. <a href="#t_pointer">Pointer</a>
Reid Spencer85f5b5b2006-12-04 21:29:24 +0000[diff] [blame]2887and <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]2888<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]2889to 64-bits. <a href="#t_struct">Structure</a> types require <tt>i32</tt>
Reid Spencer42ddd842006-12-03 16:53:48 +0000[diff] [blame]2890<b>constants</b>.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2891
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2892<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]2893type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2894}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2895the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
2896i8 }</tt>' type, another structure. The third index indexes into the second
2897element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2898array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2899'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
2900to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2901
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2902<p>Note that it is perfectly legal to index partially through a
2903structure, returning a pointer to an inner element. Because of this,
2904the LLVM code for the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2905
2906<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2907 define i32* %foo(%ST* %s) {
2908 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2909 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
2910 %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]2911 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
2912 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
2913 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2914 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2915</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]2916
2917<p>Note that it is undefined to access an array out of bounds: array and
2918pointer indexes must always be within the defined bounds of the array type.
2919The one exception for this rules is zero length arrays. These arrays are
2920defined to be accessible as variable length arrays, which requires access
2921beyond the zero'th element.</p>
2922
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]2923<p>The getelementptr instruction is often confusing. For some more insight
2924into how it works, see <a href="GetElementPtr.html">the getelementptr
2925FAQ</a>.</p>
2926
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2927<h5>Example:</h5>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]2928
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2929<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2930 <i>; yields [12 x i8]*:aptr</i>
2931 %aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2932</pre>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2933</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]2934
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2935<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]2936<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2937</div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2938<div class="doc_text">
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]2939<p>The instructions in this category are the conversion instructions (casting)
2940which all take a single operand and a type. They perform various bit conversions
2941on the operand.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2942</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]2943
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2944<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]2945<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2946 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
2947</div>
2948<div class="doc_text">
2949
2950<h5>Syntax:</h5>
2951<pre>
2952 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
2953</pre>
2954
2955<h5>Overview:</h5>
2956<p>
2957The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
2958</p>
2959
2960<h5>Arguments:</h5>
2961<p>
2962The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
2963be 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]2964and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2965type. The bit size of <tt>value</tt> must be larger than the bit size of
2966<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2967
2968<h5>Semantics:</h5>
2969<p>
2970The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2971and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
2972larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
2973It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2974
2975<h5>Example:</h5>
2976<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2977 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2978 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
2979 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2980</pre>
2981</div>
2982
2983<!-- _______________________________________________________________________ -->
2984<div class="doc_subsubsection">
2985 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
2986</div>
2987<div class="doc_text">
2988
2989<h5>Syntax:</h5>
2990<pre>
2991 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
2992</pre>
2993
2994<h5>Overview:</h5>
2995<p>The '<tt>zext</tt>' instruction zero extends its operand to type
2996<tt>ty2</tt>.</p>
2997
2998
2999<h5>Arguments:</h5>
3000<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]3001<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3002also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3003<tt>value</tt> must be smaller than the bit size of the destination type,
3004<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3005
3006<h5>Semantics:</h5>
3007<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]3008bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3009
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]3010<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]3011
3012<h5>Example:</h5>
3013<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3014 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3015 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3016</pre>
3017</div>
3018
3019<!-- _______________________________________________________________________ -->
3020<div class="doc_subsubsection">
3021 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3022</div>
3023<div class="doc_text">
3024
3025<h5>Syntax:</h5>
3026<pre>
3027 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3028</pre>
3029
3030<h5>Overview:</h5>
3031<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3032
3033<h5>Arguments:</h5>
3034<p>
3035The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3036<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3037also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3038<tt>value</tt> must be smaller than the bit size of the destination type,
3039<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3040
3041<h5>Semantics:</h5>
3042<p>
3043The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3044bit (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]3045the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3046
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3047<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]3048
3049<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3050<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3051 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3052 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3053</pre>
3054</div>
3055
3056<!-- _______________________________________________________________________ -->
3057<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3058 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3059</div>
3060
3061<div class="doc_text">
3062
3063<h5>Syntax:</h5>
3064
3065<pre>
3066 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3067</pre>
3068
3069<h5>Overview:</h5>
3070<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3071<tt>ty2</tt>.</p>
3072
3073
3074<h5>Arguments:</h5>
3075<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3076 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3077cast it to. The size of <tt>value</tt> must be larger than the size of
3078<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3079<i>no-op cast</i>.</p>
3080
3081<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3082<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3083<a href="#t_floating">floating point</a> type to a smaller
3084<a href="#t_floating">floating point</a> type. If the value cannot fit within
3085the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3086
3087<h5>Example:</h5>
3088<pre>
3089 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3090 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3091</pre>
3092</div>
3093
3094<!-- _______________________________________________________________________ -->
3095<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3096 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3097</div>
3098<div class="doc_text">
3099
3100<h5>Syntax:</h5>
3101<pre>
3102 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3103</pre>
3104
3105<h5>Overview:</h5>
3106<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3107floating point value.</p>
3108
3109<h5>Arguments:</h5>
3110<p>The '<tt>fpext</tt>' instruction takes a
3111<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3112and a <a href="#t_floating">floating point</a> type to cast it to. The source
3113type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3114
3115<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3116<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3117<a href="#t_floating">floating point</a> type to a larger
3118<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3119used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3120<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]3121
3122<h5>Example:</h5>
3123<pre>
3124 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3125 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3126</pre>
3127</div>
3128
3129<!-- _______________________________________________________________________ -->
3130<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]3131 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3132</div>
3133<div class="doc_text">
3134
3135<h5>Syntax:</h5>
3136<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3137 &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]3138</pre>
3139
3140<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3141<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3142unsigned integer equivalent of type <tt>ty2</tt>.
3143</p>
3144
3145<h5>Arguments:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3146<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^]3147scalar or vector <a href="#t_floating">floating point</a> value, and a type
3148to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3149type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3150vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3151
3152<h5>Semantics:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3153<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3154<a href="#t_floating">floating point</a> operand into the nearest (rounding
3155towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3156the results are undefined.</p>
3157
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3158<h5>Example:</h5>
3159<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3160 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3161 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3162 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3163</pre>
3164</div>
3165
3166<!-- _______________________________________________________________________ -->
3167<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3168 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3169</div>
3170<div class="doc_text">
3171
3172<h5>Syntax:</h5>
3173<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3174 &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]3175</pre>
3176
3177<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3178<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3179<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]3180</p>
3181
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3182<h5>Arguments:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3183<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^]3184scalar or vector <a href="#t_floating">floating point</a> value, and a type
3185to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3186type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3187vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3188
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3189<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3190<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3191<a href="#t_floating">floating point</a> operand into the nearest (rounding
3192towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3193the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3194
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3195<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3196<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3197 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3198 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3199 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3200</pre>
3201</div>
3202
3203<!-- _______________________________________________________________________ -->
3204<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3205 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3206</div>
3207<div class="doc_text">
3208
3209<h5>Syntax:</h5>
3210<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3211 &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]3212</pre>
3213
3214<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3215<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3216integer and converts that value to the <tt>ty2</tt> type.</p>
3217
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3218<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame^]3219<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3220scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3221to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3222type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3223floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3224
3225<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3226<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3227integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3228the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3229
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3230<h5>Example:</h5>
3231<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3232 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3233 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3234</pre>
3235</div>
3236
3237<!-- _______________________________________________________________________ -->
3238<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3239 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3240</div>
3241<div class="doc_text">
3242
3243<h5>Syntax:</h5>
3244<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3245 &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]3246</pre>
3247
3248<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3249<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3250integer and converts that value to the <tt>ty2</tt> type.</p>
3251
3252<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame^]3253<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3254scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3255to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3256type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3257floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3258
3259<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3260<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3261integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3262the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3263
3264<h5>Example:</h5>
3265<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3266 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3267 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3268</pre>
3269</div>
3270
3271<!-- _______________________________________________________________________ -->
3272<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3273 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3274</div>
3275<div class="doc_text">
3276
3277<h5>Syntax:</h5>
3278<pre>
3279 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3280</pre>
3281
3282<h5>Overview:</h5>
3283<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3284the integer type <tt>ty2</tt>.</p>
3285
3286<h5>Arguments:</h5>
3287<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3288must 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]3289<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
3290
3291<h5>Semantics:</h5>
3292<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3293<tt>ty2</tt> by interpreting the pointer value as an integer and either
3294truncating or zero extending that value to the size of the integer type. If
3295<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3296<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]3297are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3298change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3299
3300<h5>Example:</h5>
3301<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3302 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3303 %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]3304</pre>
3305</div>
3306
3307<!-- _______________________________________________________________________ -->
3308<div class="doc_subsubsection">
3309 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3310</div>
3311<div class="doc_text">
3312
3313<h5>Syntax:</h5>
3314<pre>
3315 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3316</pre>
3317
3318<h5>Overview:</h5>
3319<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
3320a pointer type, <tt>ty2</tt>.</p>
3321
3322<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3323<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3324value to cast, and a type to cast it to, which must be a
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]3325<a href="#t_pointer">pointer</a> type.
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3326
3327<h5>Semantics:</h5>
3328<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
3329<tt>ty2</tt> by applying either a zero extension or a truncation depending on
3330the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
3331size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
3332the size of a pointer then a zero extension is done. If they are the same size,
3333nothing is done (<i>no-op cast</i>).</p>
3334
3335<h5>Example:</h5>
3336<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3337 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
3338 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
3339 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3340</pre>
3341</div>
3342
3343<!-- _______________________________________________________________________ -->
3344<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3345 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3346</div>
3347<div class="doc_text">
3348
3349<h5>Syntax:</h5>
3350<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3351 &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]3352</pre>
3353
3354<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3355<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3356<tt>ty2</tt> without changing any bits.</p>
3357
3358<h5>Arguments:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3359<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3360a first class value, and a type to cast it to, which must also be a <a
3361 href="#t_firstclass">first class</a> type. The bit sizes of <tt>value</tt>
Reid Spencer19b569f2007-01-09 20:08:58 +0000[diff] [blame]3362and the destination type, <tt>ty2</tt>, must be identical. If the source
3363type is a pointer, the destination type must also be a pointer.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3364
3365<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3366<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3367<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
3368this conversion. The conversion is done as if the <tt>value</tt> had been
3369stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
3370converted to other pointer types with this instruction. To convert pointers to
3371other types, use the <a href="#i_inttoptr">inttoptr</a> or
3372<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3373
3374<h5>Example:</h5>
3375<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3376 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3377 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
3378 %Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3379</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3380</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3381
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3382<!-- ======================================================================= -->
3383<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
3384<div class="doc_text">
3385<p>The instructions in this category are the "miscellaneous"
3386instructions, which defy better classification.</p>
3387</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3388
3389<!-- _______________________________________________________________________ -->
3390<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
3391</div>
3392<div class="doc_text">
3393<h5>Syntax:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3394<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]3395</pre>
3396<h5>Overview:</h5>
3397<p>The '<tt>icmp</tt>' instruction returns a boolean value based on comparison
3398of its two integer operands.</p>
3399<h5>Arguments:</h5>
3400<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3401the condition code indicating the kind of comparison to perform. It is not
3402a value, just a keyword. The possible condition code are:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3403<ol>
3404 <li><tt>eq</tt>: equal</li>
3405 <li><tt>ne</tt>: not equal </li>
3406 <li><tt>ugt</tt>: unsigned greater than</li>
3407 <li><tt>uge</tt>: unsigned greater or equal</li>
3408 <li><tt>ult</tt>: unsigned less than</li>
3409 <li><tt>ule</tt>: unsigned less or equal</li>
3410 <li><tt>sgt</tt>: signed greater than</li>
3411 <li><tt>sge</tt>: signed greater or equal</li>
3412 <li><tt>slt</tt>: signed less than</li>
3413 <li><tt>sle</tt>: signed less or equal</li>
3414</ol>
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3415<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Reid Spencer350f8aa2007-01-04 05:19:58 +0000[diff] [blame]3416<a href="#t_pointer">pointer</a> typed. They must also be identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3417<h5>Semantics:</h5>
3418<p>The '<tt>icmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
3419the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3420yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3421<ol>
3422 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
3423 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3424 </li>
3425 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
3426 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3427 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
3428 <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
3429 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
3430 <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
3431 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
3432 <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
3433 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
3434 <tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
3435 <li><tt>sgt</tt>: interprets the operands as signed values and yields
3436 <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
3437 <li><tt>sge</tt>: interprets the operands as signed values and yields
3438 <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
3439 <li><tt>slt</tt>: interprets the operands as signed values and yields
3440 <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
3441 <li><tt>sle</tt>: interprets the operands as signed values and yields
3442 <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]3443</ol>
3444<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3445values are compared as if they were integers.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3446
3447<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3448<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
3449 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
3450 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
3451 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
3452 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
3453 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3454</pre>
3455</div>
3456
3457<!-- _______________________________________________________________________ -->
3458<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
3459</div>
3460<div class="doc_text">
3461<h5>Syntax:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3462<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]3463</pre>
3464<h5>Overview:</h5>
3465<p>The '<tt>fcmp</tt>' instruction returns a boolean value based on comparison
3466of its floating point operands.</p>
3467<h5>Arguments:</h5>
3468<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3469the condition code indicating the kind of comparison to perform. It is not
3470a value, just a keyword. The possible condition code are:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3471<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3472 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3473 <li><tt>oeq</tt>: ordered and equal</li>
3474 <li><tt>ogt</tt>: ordered and greater than </li>
3475 <li><tt>oge</tt>: ordered and greater than or equal</li>
3476 <li><tt>olt</tt>: ordered and less than </li>
3477 <li><tt>ole</tt>: ordered and less than or equal</li>
3478 <li><tt>one</tt>: ordered and not equal</li>
3479 <li><tt>ord</tt>: ordered (no nans)</li>
3480 <li><tt>ueq</tt>: unordered or equal</li>
3481 <li><tt>ugt</tt>: unordered or greater than </li>
3482 <li><tt>uge</tt>: unordered or greater than or equal</li>
3483 <li><tt>ult</tt>: unordered or less than </li>
3484 <li><tt>ule</tt>: unordered or less than or equal</li>
3485 <li><tt>une</tt>: unordered or not equal</li>
3486 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3487 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3488</ol>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3489<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer93a49852006-12-06 07:08:07 +0000[diff] [blame]3490<i>unordered</i> means that either operand may be a QNAN.</p>
Reid Spencer350f8aa2007-01-04 05:19:58 +0000[diff] [blame]3491<p>The <tt>val1</tt> and <tt>val2</tt> arguments must be
3492<a href="#t_floating">floating point</a> typed. They must have identical
3493types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3494<h5>Semantics:</h5>
3495<p>The '<tt>fcmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
3496the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3497yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3498<ol>
3499 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3500 <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]3501 <tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3502 <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]3503 <tt>var1</tt> is greather than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3504 <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]3505 <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3506 <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]3507 <tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3508 <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]3509 <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3510 <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]3511 <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3512 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
3513 <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]3514 <tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3515 <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]3516 <tt>var1</tt> is greater than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3517 <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]3518 <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3519 <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]3520 <tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3521 <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]3522 <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3523 <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]3524 <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3525 <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]3526 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
3527</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3528
3529<h5>Example:</h5>
3530<pre> &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
3531 &lt;result&gt; = icmp one float 4.0, 5.0 <i>; yields: result=true</i>
3532 &lt;result&gt; = icmp olt float 4.0, 5.0 <i>; yields: result=true</i>
3533 &lt;result&gt; = icmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
3534</pre>
3535</div>
3536
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3537<!-- _______________________________________________________________________ -->
3538<div class="doc_subsubsection"> <a name="i_phi">'<tt>phi</tt>'
3539Instruction</a> </div>
3540<div class="doc_text">
3541<h5>Syntax:</h5>
3542<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
3543<h5>Overview:</h5>
3544<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
3545the SSA graph representing the function.</p>
3546<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3547<p>The type of the incoming values is specified with the first type
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3548field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
3549as arguments, with one pair for each predecessor basic block of the
3550current block. Only values of <a href="#t_firstclass">first class</a>
3551type may be used as the value arguments to the PHI node. Only labels
3552may be used as the label arguments.</p>
3553<p>There must be no non-phi instructions between the start of a basic
3554block and the PHI instructions: i.e. PHI instructions must be first in
3555a basic block.</p>
3556<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3557<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
3558specified by the pair corresponding to the predecessor basic block that executed
3559just prior to the current block.</p>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3560<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3561<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]3562</div>
3563
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3564<!-- _______________________________________________________________________ -->
3565<div class="doc_subsubsection">
3566 <a name="i_select">'<tt>select</tt>' Instruction</a>
3567</div>
3568
3569<div class="doc_text">
3570
3571<h5>Syntax:</h5>
3572
3573<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3574 &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]3575</pre>
3576
3577<h5>Overview:</h5>
3578
3579<p>
3580The '<tt>select</tt>' instruction is used to choose one value based on a
3581condition, without branching.
3582</p>
3583
3584
3585<h5>Arguments:</h5>
3586
3587<p>
3588The '<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.
3589</p>
3590
3591<h5>Semantics:</h5>
3592
3593<p>
3594If the boolean condition evaluates to true, the instruction returns the first
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3595value argument; otherwise, it returns the second value argument.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3596</p>
3597
3598<h5>Example:</h5>
3599
3600<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3601 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3602</pre>
3603</div>
3604
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]3605
3606<!-- _______________________________________________________________________ -->
3607<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3608 <a name="i_call">'<tt>call</tt>' Instruction</a>
3609</div>
3610
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3611<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3612
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3613<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3614<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]3615 &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]3616</pre>
3617
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3618<h5>Overview:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3619
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3620<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3621
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3622<h5>Arguments:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3623
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3624<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3625
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3626<ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3627 <li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3628 <p>The optional "tail" marker indicates whether the callee function accesses
3629 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3630 function call is eligible for tail call optimization. Note that calls may
3631 be marked "tail" even if they do not occur before a <a
3632 href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3633 </li>
3634 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3635 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3636 convention</a> the call should use. If none is specified, the call defaults
3637 to using C calling conventions.
3638 </li>
3639 <li>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]3640 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
3641 the type of the return value. Functions that return no value are marked
3642 <tt><a href="#t_void">void</a></tt>.</p>
3643 </li>
3644 <li>
3645 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
3646 value being invoked. The argument types must match the types implied by
3647 this signature. This type can be omitted if the function is not varargs
3648 and if the function type does not return a pointer to a function.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3649 </li>
3650 <li>
3651 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
3652 be invoked. In most cases, this is a direct function invocation, but
3653 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3654 to function value.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3655 </li>
3656 <li>
3657 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencera7e302a2005-05-01 22:22:57 +0000[diff] [blame]3658 function signature argument types. All arguments must be of
3659 <a href="#t_firstclass">first class</a> type. If the function signature
3660 indicates the function accepts a variable number of arguments, the extra
3661 arguments can be specified.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3662 </li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3663</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3664
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3665<h5>Semantics:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3666
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3667<p>The '<tt>call</tt>' instruction is used to cause control flow to
3668transfer to a specified function, with its incoming arguments bound to
3669the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
3670instruction in the called function, control flow continues with the
3671instruction after the function call, and the return value of the
3672function is bound to the result argument. This is a simpler case of
3673the <a href="#i_invoke">invoke</a> instruction.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3674
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3675<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3676
3677<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]3678 %retval = call i32 @test(i32 %argc)
3679 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42);
3680 %X = tail call i32 @foo()
3681 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo()
3682 %Z = call void %foo(i8 97 signext)
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3683</pre>
3684
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3685</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3686
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3687<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3688<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]3689 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3690</div>
3691
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3692<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3693
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3694<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3695
3696<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3697 &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]3698</pre>
3699
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3700<h5>Overview:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3701
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3702<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3703the "variable argument" area of a function call. It is used to implement the
3704<tt>va_arg</tt> macro in C.</p>
3705
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3706<h5>Arguments:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3707
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3708<p>This instruction takes a <tt>va_list*</tt> value and the type of
3709the argument. It returns a value of the specified argument type and
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3710increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3711actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3712
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3713<h5>Semantics:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3714
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3715<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
3716type from the specified <tt>va_list</tt> and causes the
3717<tt>va_list</tt> to point to the next argument. For more information,
3718see the variable argument handling <a href="#int_varargs">Intrinsic
3719Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3720
3721<p>It is legal for this instruction to be called in a function which does not
3722take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3723function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3724
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3725<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3726href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3727argument.</p>
3728
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3729<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3730
3731<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
3732
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3733</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3734
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3735<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3736<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
3737<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3738
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3739<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3740
3741<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]3742well known names and semantics and are required to follow certain restrictions.
3743Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3744language that does not require changing all of the transformations in LLVM when
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]3745adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3746
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3747<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3748prefix is reserved in LLVM for intrinsic names; thus, function names may not
3749begin with this prefix. Intrinsic functions must always be external functions:
3750you cannot define the body of intrinsic functions. Intrinsic functions may
3751only be used in call or invoke instructions: it is illegal to take the address
3752of an intrinsic function. Additionally, because intrinsic functions are part
3753of the LLVM language, it is required if any are added that they be documented
3754here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3755
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]3756<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
3757a family of functions that perform the same operation but on different data
3758types. Because LLVM can represent over 8 million different integer types,
3759overloading is used commonly to allow an intrinsic function to operate on any
3760integer type. One or more of the argument types or the result type can be
3761overloaded to accept any integer type. Argument types may also be defined as
3762exactly matching a previous argument's type or the result type. This allows an
3763intrinsic function which accepts multiple arguments, but needs all of them to
3764be of the same type, to only be overloaded with respect to a single argument or
3765the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3766
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]3767<p>Overloaded intrinsics will have the names of its overloaded argument types
3768encoded into its function name, each preceded by a period. Only those types
3769which are overloaded result in a name suffix. Arguments whose type is matched
3770against another type do not. For example, the <tt>llvm.ctpop</tt> function can
3771take an integer of any width and returns an integer of exactly the same integer
3772width. This leads to a family of functions such as
3773<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
3774Only one type, the return type, is overloaded, and only one type suffix is
3775required. Because the argument's type is matched against the return type, it
3776does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]3777
3778<p>To learn how to add an intrinsic function, please see the
3779<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3780</p>
3781
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3782</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3783
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3784<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3785<div class="doc_subsection">
3786 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
3787</div>
3788
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3789<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3790
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3791<p>Variable argument support is defined in LLVM with the <a
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]3792 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3793intrinsic functions. These functions are related to the similarly
3794named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3795
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3796<p>All of these functions operate on arguments that use a
3797target-specific value type "<tt>va_list</tt>". The LLVM assembly
3798language reference manual does not define what this type is, so all
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3799transformations should be prepared to handle these functions regardless of
3800the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3801
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]3802<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]3803instruction and the variable argument handling intrinsic functions are
3804used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3805
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3806<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3807<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3808define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3809 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3810 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3811 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3812 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3813
3814 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3815 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3816
3817 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3818 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3819 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3820 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3821 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3822
3823 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3824 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3825 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3826}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3827
3828declare void @llvm.va_start(i8*)
3829declare void @llvm.va_copy(i8*, i8*)
3830declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3831</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3832</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3833
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3834</div>
3835
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3836<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3837<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3838 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3839</div>
3840
3841
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3842<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3843<h5>Syntax:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3844<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3845<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3846<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
3847<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
3848href="#i_va_arg">va_arg</a></tt>.</p>
3849
3850<h5>Arguments:</h5>
3851
3852<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
3853
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3854<h5>Semantics:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3855
3856<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
3857macro available in C. In a target-dependent way, it initializes the
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3858<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]3859<tt>va_arg</tt> will produce the first variable argument passed to the function.
3860Unlike 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]3861last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3862
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3863</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3864
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3865<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3866<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3867 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3868</div>
3869
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3870<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3871<h5>Syntax:</h5>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]3872<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3873<h5>Overview:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3874
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3875<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3876which 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]3877or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3878
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3879<h5>Arguments:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3880
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3881<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]3882
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3883<h5>Semantics:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3884
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3885<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]3886macro available in C. In a target-dependent way, it destroys the
3887<tt>va_list</tt> element to which the argument points. Calls to <a
3888href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
3889<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
3890<tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3891
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3892</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3893
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3894<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3895<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3896 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3897</div>
3898
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3899<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3900
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3901<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3902
3903<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]3904 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3905</pre>
3906
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3907<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3908
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3909<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
3910from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3911
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3912<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3913
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3914<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]3915The 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]3916
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3917
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3918<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3919
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3920<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
3921macro available in C. In a target-dependent way, it copies the source
3922<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
3923intrinsic is necessary because the <tt><a href="#int_va_start">
3924llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
3925example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3926
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3927</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3928
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3929<!-- ======================================================================= -->
3930<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3931 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
3932</div>
3933
3934<div class="doc_text">
3935
3936<p>
3937LLVM support for <a href="GarbageCollection.html">Accurate Garbage
3938Collection</a> requires the implementation and generation of these intrinsics.
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3939These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3940stack</a>, as well as garbage collector implementations that require <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3941href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3942Front-ends for type-safe garbage collected languages should generate these
3943intrinsics to make use of the LLVM garbage collectors. For more details, see <a
3944href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
3945</p>
3946</div>
3947
3948<!-- _______________________________________________________________________ -->
3949<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3950 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3951</div>
3952
3953<div class="doc_text">
3954
3955<h5>Syntax:</h5>
3956
3957<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]3958 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3959</pre>
3960
3961<h5>Overview:</h5>
3962
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3963<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]3964the code generator, and allows some metadata to be associated with it.</p>
3965
3966<h5>Arguments:</h5>
3967
3968<p>The first argument specifies the address of a stack object that contains the
3969root pointer. The second pointer (which must be either a constant or a global
3970value address) contains the meta-data to be associated with the root.</p>
3971
3972<h5>Semantics:</h5>
3973
3974<p>At runtime, a call to this intrinsics stores a null pointer into the "ptrloc"
3975location. At compile-time, the code generator generates information to allow
3976the runtime to find the pointer at GC safe points.
3977</p>
3978
3979</div>
3980
3981
3982<!-- _______________________________________________________________________ -->
3983<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3984 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3985</div>
3986
3987<div class="doc_text">
3988
3989<h5>Syntax:</h5>
3990
3991<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]3992 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3993</pre>
3994
3995<h5>Overview:</h5>
3996
3997<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
3998locations, allowing garbage collector implementations that require read
3999barriers.</p>
4000
4001<h5>Arguments:</h5>
4002
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4003<p>The second argument is the address to read from, which should be an address
4004allocated from the garbage collector. The first object is a pointer to the
4005start of the referenced object, if needed by the language runtime (otherwise
4006null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4007
4008<h5>Semantics:</h5>
4009
4010<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4011instruction, but may be replaced with substantially more complex code by the
4012garbage collector runtime, as needed.</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_gcwrite">'<tt>llvm.gcwrite</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 void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4028</pre>
4029
4030<h5>Overview:</h5>
4031
4032<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4033locations, allowing garbage collector implementations that require write
4034barriers (such as generational or reference counting collectors).</p>
4035
4036<h5>Arguments:</h5>
4037
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4038<p>The first argument is the reference to store, the second is the start of the
4039object to store it to, and the third is the address of the field of Obj to
4040store to. If the runtime does not require a pointer to the object, Obj may be
4041null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4042
4043<h5>Semantics:</h5>
4044
4045<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
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<!-- ======================================================================= -->
4054<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4055 <a name="int_codegen">Code Generator Intrinsics</a>
4056</div>
4057
4058<div class="doc_text">
4059<p>
4060These intrinsics are provided by LLVM to expose special features that may only
4061be implemented with code generator support.
4062</p>
4063
4064</div>
4065
4066<!-- _______________________________________________________________________ -->
4067<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4068 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4069</div>
4070
4071<div class="doc_text">
4072
4073<h5>Syntax:</h5>
4074<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4075 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4076</pre>
4077
4078<h5>Overview:</h5>
4079
4080<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4081The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4082target-specific value indicating the return address of the current function
4083or one of its callers.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4084</p>
4085
4086<h5>Arguments:</h5>
4087
4088<p>
4089The argument to this intrinsic indicates which function to return the address
4090for. Zero indicates the calling function, one indicates its caller, etc. The
4091argument is <b>required</b> to be a constant integer value.
4092</p>
4093
4094<h5>Semantics:</h5>
4095
4096<p>
4097The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4098the return address of the specified call frame, or zero if it cannot be
4099identified. The value returned by this intrinsic is likely to be incorrect or 0
4100for arguments other than zero, so it should only be used for debugging purposes.
4101</p>
4102
4103<p>
4104Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4105aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4106source-language caller.
4107</p>
4108</div>
4109
4110
4111<!-- _______________________________________________________________________ -->
4112<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4113 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4114</div>
4115
4116<div class="doc_text">
4117
4118<h5>Syntax:</h5>
4119<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4120 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4121</pre>
4122
4123<h5>Overview:</h5>
4124
4125<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4126The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
4127target-specific frame pointer value for the specified stack frame.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4128</p>
4129
4130<h5>Arguments:</h5>
4131
4132<p>
4133The argument to this intrinsic indicates which function to return the frame
4134pointer for. Zero indicates the calling function, one indicates its caller,
4135etc. The argument is <b>required</b> to be a constant integer value.
4136</p>
4137
4138<h5>Semantics:</h5>
4139
4140<p>
4141The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
4142the frame address of the specified call frame, or zero if it cannot be
4143identified. The value returned by this intrinsic is likely to be incorrect or 0
4144for arguments other than zero, so it should only be used for debugging purposes.
4145</p>
4146
4147<p>
4148Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4149aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4150source-language caller.
4151</p>
4152</div>
4153
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4154<!-- _______________________________________________________________________ -->
4155<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4156 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4157</div>
4158
4159<div class="doc_text">
4160
4161<h5>Syntax:</h5>
4162<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4163 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4164</pre>
4165
4166<h5>Overview:</h5>
4167
4168<p>
4169The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4170the function stack, for use with <a href="#int_stackrestore">
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4171<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
4172features like scoped automatic variable sized arrays in C99.
4173</p>
4174
4175<h5>Semantics:</h5>
4176
4177<p>
4178This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4179href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4180<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
4181<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
4182state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
4183practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
4184that were allocated after the <tt>llvm.stacksave</tt> was executed.
4185</p>
4186
4187</div>
4188
4189<!-- _______________________________________________________________________ -->
4190<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4191 <a name="int_stackrestore">'<tt>llvm.stackrestore</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>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4198 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4199</pre>
4200
4201<h5>Overview:</h5>
4202
4203<p>
4204The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
4205the function stack to the state it was in when the corresponding <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4206href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4207useful for implementing language features like scoped automatic variable sized
4208arrays in C99.
4209</p>
4210
4211<h5>Semantics:</h5>
4212
4213<p>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4214See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4215</p>
4216
4217</div>
4218
4219
4220<!-- _______________________________________________________________________ -->
4221<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4222 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4223</div>
4224
4225<div class="doc_text">
4226
4227<h5>Syntax:</h5>
4228<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4229 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]4230</pre>
4231
4232<h5>Overview:</h5>
4233
4234
4235<p>
4236The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4237a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
4238no
4239effect on the behavior of the program but can change its performance
Chris Lattner2a615362005-02-28 19:47:14 +0000[diff] [blame]4240characteristics.
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4241</p>
4242
4243<h5>Arguments:</h5>
4244
4245<p>
4246<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
4247determining if the fetch should be for a read (0) or write (1), and
4248<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattneraeffb4a2005-03-07 20:31:38 +0000[diff] [blame]4249locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4250<tt>locality</tt> arguments must be constant integers.
4251</p>
4252
4253<h5>Semantics:</h5>
4254
4255<p>
4256This intrinsic does not modify the behavior of the program. In particular,
4257prefetches cannot trap and do not produce a value. On targets that support this
4258intrinsic, the prefetch can provide hints to the processor cache for better
4259performance.
4260</p>
4261
4262</div>
4263
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4264<!-- _______________________________________________________________________ -->
4265<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4266 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4267</div>
4268
4269<div class="doc_text">
4270
4271<h5>Syntax:</h5>
4272<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4273 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4274</pre>
4275
4276<h5>Overview:</h5>
4277
4278
4279<p>
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4280The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
4281(PC) in a region of
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4282code to simulators and other tools. The method is target specific, but it is
4283expected that the marker will use exported symbols to transmit the PC of the marker.
Jeff Cohen25d4f7e2005-11-11 02:15:27 +0000[diff] [blame]4284The marker makes no guarantees that it will remain with any specific instruction
Chris Lattnerd07c3f42005-11-15 06:07:55 +0000[diff] [blame]4285after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb3e7afd2006-03-24 07:16:10 +0000[diff] [blame]4286optimizations. The intended use is to be inserted after optimizations to allow
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4287correlations of simulation runs.
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4288</p>
4289
4290<h5>Arguments:</h5>
4291
4292<p>
4293<tt>id</tt> is a numerical id identifying the marker.
4294</p>
4295
4296<h5>Semantics:</h5>
4297
4298<p>
4299This intrinsic does not modify the behavior of the program. Backends that do not
4300support this intrinisic may ignore it.
4301</p>
4302
4303</div>
4304
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]4305<!-- _______________________________________________________________________ -->
4306<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4307 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]4308</div>
4309
4310<div class="doc_text">
4311
4312<h5>Syntax:</h5>
4313<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4314 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]4315</pre>
4316
4317<h5>Overview:</h5>
4318
4319
4320<p>
4321The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
4322counter register (or similar low latency, high accuracy clocks) on those targets
4323that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
4324As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
4325should only be used for small timings.
4326</p>
4327
4328<h5>Semantics:</h5>
4329
4330<p>
4331When directly supported, reading the cycle counter should not modify any memory.
4332Implementations are allowed to either return a application specific value or a
4333system wide value. On backends without support, this is lowered to a constant 0.
4334</p>
4335
4336</div>
4337
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4338<!-- ======================================================================= -->
4339<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4340 <a name="int_libc">Standard C Library Intrinsics</a>
4341</div>
4342
4343<div class="doc_text">
4344<p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4345LLVM provides intrinsics for a few important standard C library functions.
4346These intrinsics allow source-language front-ends to pass information about the
4347alignment of the pointer arguments to the code generator, providing opportunity
4348for more efficient code generation.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4349</p>
4350
4351</div>
4352
4353<!-- _______________________________________________________________________ -->
4354<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4355 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4356</div>
4357
4358<div class="doc_text">
4359
4360<h5>Syntax:</h5>
4361<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4362 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4363 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4364 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4365 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4366</pre>
4367
4368<h5>Overview:</h5>
4369
4370<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4371The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4372location to the destination location.
4373</p>
4374
4375<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4376Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
4377intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4378</p>
4379
4380<h5>Arguments:</h5>
4381
4382<p>
4383The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4384the source. The third argument is an integer argument
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4385specifying the number of bytes to copy, and the fourth argument is the alignment
4386of the source and destination locations.
4387</p>
4388
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4389<p>
4390If 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]4391the caller guarantees that both the source and destination pointers are aligned
4392to that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4393</p>
4394
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4395<h5>Semantics:</h5>
4396
4397<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4398The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4399location to the destination location, which are not allowed to overlap. It
4400copies "len" bytes of memory over. If the argument is known to be aligned to
4401some boundary, this can be specified as the fourth argument, otherwise it should
4402be set to 0 or 1.
4403</p>
4404</div>
4405
4406
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4407<!-- _______________________________________________________________________ -->
4408<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4409 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4410</div>
4411
4412<div class="doc_text">
4413
4414<h5>Syntax:</h5>
4415<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4416 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4417 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4418 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4419 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4420</pre>
4421
4422<h5>Overview:</h5>
4423
4424<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4425The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
4426location to the destination location. It is similar to the
4427'<tt>llvm.memcmp</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4428</p>
4429
4430<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4431Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
4432intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4433</p>
4434
4435<h5>Arguments:</h5>
4436
4437<p>
4438The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4439the source. The third argument is an integer argument
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4440specifying the number of bytes to copy, and the fourth argument is the alignment
4441of the source and destination locations.
4442</p>
4443
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4444<p>
4445If 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]4446the caller guarantees that the source and destination pointers are aligned to
4447that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4448</p>
4449
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4450<h5>Semantics:</h5>
4451
4452<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4453The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4454location to the destination location, which may overlap. It
4455copies "len" bytes of memory over. If the argument is known to be aligned to
4456some boundary, this can be specified as the fourth argument, otherwise it should
4457be set to 0 or 1.
4458</p>
4459</div>
4460
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4461
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4462<!-- _______________________________________________________________________ -->
4463<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4464 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4465</div>
4466
4467<div class="doc_text">
4468
4469<h5>Syntax:</h5>
4470<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4471 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4472 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4473 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4474 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4475</pre>
4476
4477<h5>Overview:</h5>
4478
4479<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4480The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4481byte value.
4482</p>
4483
4484<p>
4485Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
4486does not return a value, and takes an extra alignment argument.
4487</p>
4488
4489<h5>Arguments:</h5>
4490
4491<p>
4492The first argument is a pointer to the destination to fill, the second is the
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4493byte value to fill it with, the third argument is an integer
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4494argument specifying the number of bytes to fill, and the fourth argument is the
4495known alignment of destination location.
4496</p>
4497
4498<p>
4499If 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]4500the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4501</p>
4502
4503<h5>Semantics:</h5>
4504
4505<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4506The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
4507the
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4508destination location. If the argument is known to be aligned to some boundary,
4509this can be specified as the fourth argument, otherwise it should be set to 0 or
45101.
4511</p>
4512</div>
4513
4514
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]4515<!-- _______________________________________________________________________ -->
4516<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4517 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4518</div>
4519
4520<div class="doc_text">
4521
4522<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4523<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]4524floating point or vector of floating point type. Not all targets support all
4525types however.
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4526<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4527 declare float @llvm.sqrt.f32(float %Val)
4528 declare double @llvm.sqrt.f64(double %Val)
4529 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
4530 declare fp128 @llvm.sqrt.f128(fp128 %Val)
4531 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4532</pre>
4533
4534<h5>Overview:</h5>
4535
4536<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4537The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4538returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4539<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
4540negative numbers (which allows for better optimization).
4541</p>
4542
4543<h5>Arguments:</h5>
4544
4545<p>
4546The argument and return value are floating point numbers of the same type.
4547</p>
4548
4549<h5>Semantics:</h5>
4550
4551<p>
Dan Gohmand6257fe2007-07-16 14:37:41 +0000[diff] [blame]4552This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4553floating point number.
4554</p>
4555</div>
4556
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4557<!-- _______________________________________________________________________ -->
4558<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4559 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4560</div>
4561
4562<div class="doc_text">
4563
4564<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4565<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]4566floating point or vector of floating point type. Not all targets support all
4567types however.
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4568<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4569 declare float @llvm.powi.f32(float %Val, i32 %power)
4570 declare double @llvm.powi.f64(double %Val, i32 %power)
4571 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
4572 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
4573 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4574</pre>
4575
4576<h5>Overview:</h5>
4577
4578<p>
4579The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
4580specified (positive or negative) power. The order of evaluation of
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4581multiplications is not defined. When a vector of floating point type is
4582used, the second argument remains a scalar integer value.
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4583</p>
4584
4585<h5>Arguments:</h5>
4586
4587<p>
4588The second argument is an integer power, and the first is a value to raise to
4589that power.
4590</p>
4591
4592<h5>Semantics:</h5>
4593
4594<p>
4595This function returns the first value raised to the second power with an
4596unspecified sequence of rounding operations.</p>
4597</div>
4598
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4599<!-- _______________________________________________________________________ -->
4600<div class="doc_subsubsection">
4601 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
4602</div>
4603
4604<div class="doc_text">
4605
4606<h5>Syntax:</h5>
4607<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
4608floating point or vector of floating point type. Not all targets support all
4609types however.
4610<pre>
4611 declare float @llvm.sin.f32(float %Val)
4612 declare double @llvm.sin.f64(double %Val)
4613 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
4614 declare fp128 @llvm.sin.f128(fp128 %Val)
4615 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
4616</pre>
4617
4618<h5>Overview:</h5>
4619
4620<p>
4621The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
4622</p>
4623
4624<h5>Arguments:</h5>
4625
4626<p>
4627The argument and return value are floating point numbers of the same type.
4628</p>
4629
4630<h5>Semantics:</h5>
4631
4632<p>
4633This function returns the sine of the specified operand, returning the
4634same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]4635conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4636</div>
4637
4638<!-- _______________________________________________________________________ -->
4639<div class="doc_subsubsection">
4640 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
4641</div>
4642
4643<div class="doc_text">
4644
4645<h5>Syntax:</h5>
4646<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
4647floating point or vector of floating point type. Not all targets support all
4648types however.
4649<pre>
4650 declare float @llvm.cos.f32(float %Val)
4651 declare double @llvm.cos.f64(double %Val)
4652 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
4653 declare fp128 @llvm.cos.f128(fp128 %Val)
4654 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
4655</pre>
4656
4657<h5>Overview:</h5>
4658
4659<p>
4660The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
4661</p>
4662
4663<h5>Arguments:</h5>
4664
4665<p>
4666The argument and return value are floating point numbers of the same type.
4667</p>
4668
4669<h5>Semantics:</h5>
4670
4671<p>
4672This function returns the cosine of the specified operand, returning the
4673same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]4674conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4675</div>
4676
4677<!-- _______________________________________________________________________ -->
4678<div class="doc_subsubsection">
4679 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
4680</div>
4681
4682<div class="doc_text">
4683
4684<h5>Syntax:</h5>
4685<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
4686floating point or vector of floating point type. Not all targets support all
4687types however.
4688<pre>
4689 declare float @llvm.pow.f32(float %Val, float %Power)
4690 declare double @llvm.pow.f64(double %Val, double %Power)
4691 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
4692 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
4693 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
4694</pre>
4695
4696<h5>Overview:</h5>
4697
4698<p>
4699The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
4700specified (positive or negative) power.
4701</p>
4702
4703<h5>Arguments:</h5>
4704
4705<p>
4706The second argument is a floating point power, and the first is a value to
4707raise to that power.
4708</p>
4709
4710<h5>Semantics:</h5>
4711
4712<p>
4713This function returns the first value raised to the second power,
4714returning the
4715same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]4716conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4717</div>
4718
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4719
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4720<!-- ======================================================================= -->
4721<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4722 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4723</div>
4724
4725<div class="doc_text">
4726<p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4727LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4728These allow efficient code generation for some algorithms.
4729</p>
4730
4731</div>
4732
4733<!-- _______________________________________________________________________ -->
4734<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4735 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4736</div>
4737
4738<div class="doc_text">
4739
4740<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4741<p>This is an overloaded intrinsic function. You can use bswap on any integer
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4742type that is an even number of bytes (i.e. BitWidth % 16 == 0).
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4743<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4744 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
4745 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
4746 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4747</pre>
4748
4749<h5>Overview:</h5>
4750
4751<p>
Reid Spencer338ea092007-04-02 02:25:19 +0000[diff] [blame]4752The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4753values with an even number of bytes (positive multiple of 16 bits). These are
4754useful for performing operations on data that is not in the target's native
4755byte order.
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4756</p>
4757
4758<h5>Semantics:</h5>
4759
4760<p>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4761The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4762and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
4763intrinsic returns an i32 value that has the four bytes of the input i32
4764swapped, 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]4765i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
4766<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4767additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4768</p>
4769
4770</div>
4771
4772<!-- _______________________________________________________________________ -->
4773<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4774 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4775</div>
4776
4777<div class="doc_text">
4778
4779<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4780<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
4781width. Not all targets support all bit widths however.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4782<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4783 declare i8 @llvm.ctpop.i8 (i8 &lt;src&gt;)
4784 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4785 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4786 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
4787 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4788</pre>
4789
4790<h5>Overview:</h5>
4791
4792<p>
Chris Lattnerec6cb612006-01-16 22:38:59 +0000[diff] [blame]4793The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
4794value.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4795</p>
4796
4797<h5>Arguments:</h5>
4798
4799<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]4800The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]4801integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4802</p>
4803
4804<h5>Semantics:</h5>
4805
4806<p>
4807The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
4808</p>
4809</div>
4810
4811<!-- _______________________________________________________________________ -->
4812<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]4813 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4814</div>
4815
4816<div class="doc_text">
4817
4818<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4819<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
4820integer bit width. Not all targets support all bit widths however.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4821<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4822 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
4823 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4824 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4825 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
4826 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4827</pre>
4828
4829<h5>Overview:</h5>
4830
4831<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4832The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
4833leading zeros in a variable.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4834</p>
4835
4836<h5>Arguments:</h5>
4837
4838<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]4839The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]4840integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4841</p>
4842
4843<h5>Semantics:</h5>
4844
4845<p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4846The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
4847in 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]4848of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4849</p>
4850</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]4851
4852
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4853
4854<!-- _______________________________________________________________________ -->
4855<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]4856 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4857</div>
4858
4859<div class="doc_text">
4860
4861<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4862<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
4863integer bit width. Not all targets support all bit widths however.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4864<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4865 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
4866 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4867 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4868 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
4869 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4870</pre>
4871
4872<h5>Overview:</h5>
4873
4874<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4875The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
4876trailing zeros.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4877</p>
4878
4879<h5>Arguments:</h5>
4880
4881<p>
4882The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]4883integer type. The return type must match the argument type.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4884</p>
4885
4886<h5>Semantics:</h5>
4887
4888<p>
4889The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
4890in a variable. If the src == 0 then the result is the size in bits of the type
4891of src. For example, <tt>llvm.cttz(2) = 1</tt>.
4892</p>
4893</div>
4894
Reid Spencer497d93e2007-04-01 08:27:01 +0000[diff] [blame]4895<!-- _______________________________________________________________________ -->
4896<div class="doc_subsubsection">
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4897 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4898</div>
4899
4900<div class="doc_text">
4901
4902<h5>Syntax:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4903<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4904on any integer bit width.
4905<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4906 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
4907 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4908</pre>
4909
4910<h5>Overview:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4911<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4912range of bits from an integer value and returns them in the same bit width as
4913the original value.</p>
4914
4915<h5>Arguments:</h5>
4916<p>The first argument, <tt>%val</tt> and the result may be integer types of
4917any bit width but they must have the same bit width. The second and third
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4918arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4919
4920<h5>Semantics:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4921<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4922of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
4923<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
4924operates in forward mode.</p>
4925<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
4926right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4927only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
4928<ol>
4929 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
4930 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
4931 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
4932 to determine the number of bits to retain.</li>
4933 <li>A mask of the retained bits is created by shifting a -1 value.</li>
4934 <li>The mask is ANDed with <tt>%val</tt> to produce the result.
4935</ol>
Reid Spencerd6a85b52007-05-14 16:14:57 +0000[diff] [blame]4936<p>In reverse mode, a similar computation is made except that the bits are
4937returned in the reverse order. So, for example, if <tt>X</tt> has the value
4938<tt>i16 0x0ACF (101011001111)</tt> and we apply
4939<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
4940<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4941</div>
4942
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]4943<div class="doc_subsubsection">
4944 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
4945</div>
4946
4947<div class="doc_text">
4948
4949<h5>Syntax:</h5>
4950<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
4951on any integer bit width.
4952<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4953 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
4954 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]4955</pre>
4956
4957<h5>Overview:</h5>
4958<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
4959of bits in an integer value with another integer value. It returns the integer
4960with the replaced bits.</p>
4961
4962<h5>Arguments:</h5>
4963<p>The first argument, <tt>%val</tt> and the result may be integer types of
4964any bit width but they must have the same bit width. <tt>%val</tt> is the value
4965whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
4966integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
4967type since they specify only a bit index.</p>
4968
4969<h5>Semantics:</h5>
4970<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
4971of operation: forwards and reverse. If <tt>%lo</tt> is greater than
4972<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
4973operates in forward mode.</p>
4974<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
4975truncating it down to the size of the replacement area or zero extending it
4976up to that size.</p>
4977<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
4978are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
4979in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
4980to the <tt>%hi</tt>th bit.
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]4981<p>In reverse mode, a similar computation is made except that the bits are
4982reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
4983<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]4984<h5>Examples:</h5>
4985<pre>
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]4986 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]4987 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
4988 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
4989 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]4990 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]4991</pre>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]4992</div>
4993
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4994<!-- ======================================================================= -->
4995<div class="doc_subsection">
4996 <a name="int_debugger">Debugger Intrinsics</a>
4997</div>
4998
4999<div class="doc_text">
5000<p>
5001The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
5002are described in the <a
5003href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
5004Debugging</a> document.
5005</p>
5006</div>
5007
5008
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]5009<!-- ======================================================================= -->
5010<div class="doc_subsection">
5011 <a name="int_eh">Exception Handling Intrinsics</a>
5012</div>
5013
5014<div class="doc_text">
5015<p> The LLVM exception handling intrinsics (which all start with
5016<tt>llvm.eh.</tt> prefix), are described in the <a
5017href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
5018Handling</a> document. </p>
5019</div>
5020
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5021<!-- ======================================================================= -->
5022<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5023 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5024</div>
5025
5026<div class="doc_text">
5027<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5028 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5029 the <tt>nest</tt> attribute, from a function. The result is a callable
5030 function pointer lacking the nest parameter - the caller does not need
5031 to provide a value for it. Instead, the value to use is stored in
5032 advance in a "trampoline", a block of memory usually allocated
5033 on the stack, which also contains code to splice the nest value into the
5034 argument list. This is used to implement the GCC nested function address
5035 extension.
5036</p>
5037<p>
5038 For example, if the function is
5039 <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]5040 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]5041<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5042 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
5043 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
5044 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
5045 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5046</pre>
Bill Wendling03295ca2007-09-22 09:23:55 +0000[diff] [blame]5047 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
5048 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5049</div>
5050
5051<!-- _______________________________________________________________________ -->
5052<div class="doc_subsubsection">
5053 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
5054</div>
5055<div class="doc_text">
5056<h5>Syntax:</h5>
5057<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5058declare 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]5059</pre>
5060<h5>Overview:</h5>
5061<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5062 This fills the memory pointed to by <tt>tramp</tt> with code
5063 and returns a function pointer suitable for executing it.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5064</p>
5065<h5>Arguments:</h5>
5066<p>
5067 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
5068 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
5069 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsc00c2ba2007-08-22 23:39:54 +0000[diff] [blame]5070 intrinsic. Note that the size and the alignment are target-specific - LLVM
5071 currently provides no portable way of determining them, so a front-end that
5072 generates this intrinsic needs to have some target-specific knowledge.
5073 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]5074</p>
5075<h5>Semantics:</h5>
5076<p>
5077 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5078 dependent code, turning it into a function. A pointer to this function is
5079 returned, but needs to be bitcast to an
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5080 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5081 before being called. The new function's signature is the same as that of
5082 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
5083 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
5084 of pointer type. Calling the new function is equivalent to calling
5085 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
5086 missing <tt>nest</tt> argument. If, after calling
5087 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
5088 modified, then the effect of any later call to the returned function pointer is
5089 undefined.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5090</p>
5091</div>
5092
5093<!-- ======================================================================= -->
5094<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5095 <a name="int_general">General Intrinsics</a>
5096</div>
5097
5098<div class="doc_text">
5099<p> This class of intrinsics is designed to be generic and has
5100no specific purpose. </p>
5101</div>
5102
5103<!-- _______________________________________________________________________ -->
5104<div class="doc_subsubsection">
5105 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
5106</div>
5107
5108<div class="doc_text">
5109
5110<h5>Syntax:</h5>
5111<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]5112 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]5113</pre>
5114
5115<h5>Overview:</h5>
5116
5117<p>
5118The '<tt>llvm.var.annotation</tt>' intrinsic
5119</p>
5120
5121<h5>Arguments:</h5>
5122
5123<p>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]5124The first argument is a pointer to a value, the second is a pointer to a
5125global string, the third is a pointer to a global string which is the source
5126file name, and the last argument is the line number.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5127</p>
5128
5129<h5>Semantics:</h5>
5130
5131<p>
5132This intrinsic allows annotation of local variables with arbitrary strings.
5133This can be useful for special purpose optimizations that want to look for these
5134 annotations. These have no other defined use, they are ignored by code
5135 generation and optimization.
5136</div>
5137
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5138<!-- _______________________________________________________________________ -->
5139<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]5140 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5141</div>
5142
5143<div class="doc_text">
5144
5145<h5>Syntax:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]5146<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
5147any integer bit width.
5148</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5149<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]5150 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5151 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5152 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5153 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5154 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]5155</pre>
5156
5157<h5>Overview:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]5158
5159<p>
5160The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5161</p>
5162
5163<h5>Arguments:</h5>
5164
5165<p>
5166The first argument is an integer value (result of some expression),
5167the second is a pointer to a global string, the third is a pointer to a global
5168string which is the source file name, and the last argument is the line number.
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]5169It returns the value of the first argument.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5170</p>
5171
5172<h5>Semantics:</h5>
5173
5174<p>
5175This intrinsic allows annotations to be put on arbitrary expressions
5176with arbitrary strings. This can be useful for special purpose optimizations
5177that want to look for these annotations. These have no other defined use, they
5178are ignored by code generation and optimization.
5179</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]5180
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5181<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5182<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]5183<address>
5184 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
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5188
5189 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]5190 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]5191 Last modified: $Date$
5192</address>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5193</body>
5194</html>