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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / e1eaf916f07839c6b4ea8dbdae3884ed31d61c38 / . / docs / LangRef.html
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4<head>
5 <title>LLVM Assembly Language Reference Manual</title>
Reid Spencer3921c742004-08-26 20:44:00 +0000[diff] [blame]6 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
7 <meta name="author" content="Chris Lattner">
8 <meta name="description"
9 content="LLVM Assembly Language Reference Manual.">
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]10 <link rel="stylesheet" href="llvm.css" type="text/css">
11</head>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]14
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]15<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]16<ol>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]17 <li><a href="#abstract">Abstract</a></li>
18 <li><a href="#introduction">Introduction</a></li>
19 <li><a href="#identifiers">Identifiers</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]20 <li><a href="#highlevel">High Level Structure</a>
21 <ol>
22 <li><a href="#modulestructure">Module Structure</a></li>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a>
24 <ol>
Bill Wendling987e7eb2009-07-20 02:41:50 +0000[diff] [blame]25 <li><a href="#linkage_private">'<tt>private</tt>' Linkage</a></li>
26 <li><a href="#linkage_linker_private">'<tt>linker_private</tt>' Linkage</a></li>
27 <li><a href="#linkage_internal">'<tt>internal</tt>' Linkage</a></li>
28 <li><a href="#linkage_available_externally">'<tt>available_externally</tt>' Linkage</a></li>
29 <li><a href="#linkage_linkonce">'<tt>linkonce</tt>' Linkage</a></li>
30 <li><a href="#linkage_common">'<tt>common</tt>' Linkage</a></li>
31 <li><a href="#linkage_weak">'<tt>weak</tt>' Linkage</a></li>
32 <li><a href="#linkage_appending">'<tt>appending</tt>' Linkage</a></li>
33 <li><a href="#linkage_externweak">'<tt>extern_weak</tt>' Linkage</a></li>
34 <li><a href="#linkage_linkonce">'<tt>linkonce_odr</tt>' Linkage</a></li>
35 <li><a href="#linkage_weak">'<tt>weak_odr</tt>' Linkage</a></li>
36 <li><a href="#linkage_external">'<tt>externally visible</tt>' Linkage</a></li>
37 <li><a href="#linkage_dllimport">'<tt>dllimport</tt>' Linkage</a></li>
38 <li><a href="#linkage_dllexport">'<tt>dllexport</tt>' Linkage</a></li>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]39 </ol>
40 </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]41 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]42 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]43 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]44 <li><a href="#functionstructure">Functions</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]45 <li><a href="#aliasstructure">Aliases</a></li>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]46 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]47 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]48 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]49 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]50 <li><a href="#datalayout">Data Layout</a></li>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]51 <li><a href="#pointeraliasing">Pointer Aliasing Rules</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]52 </ol>
53 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]54 <li><a href="#typesystem">Type System</a>
55 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]56 <li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]57 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]58 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]59 <li><a href="#t_floating">Floating Point Types</a></li>
60 <li><a href="#t_void">Void Type</a></li>
61 <li><a href="#t_label">Label Type</a></li>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]62 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]63 </ol>
64 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]65 <li><a href="#t_derived">Derived Types</a>
66 <ol>
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]67 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]68 <li><a href="#t_array">Array Type</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]69 <li><a href="#t_function">Function Type</a></li>
70 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]71 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]72 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]73 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]74 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]75 </ol>
76 </li>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]77 <li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]78 </ol>
79 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]80 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]81 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]82 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]83 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]84 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
85 <li><a href="#undefvalues">Undefined Values</a></li>
86 <li><a href="#constantexprs">Constant Expressions</a></li>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]87 <li><a href="#metadata">Embedded Metadata</a></li>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]88 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]89 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]90 <li><a href="#othervalues">Other Values</a>
91 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]92 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]93 </ol>
94 </li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]95 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
96 <ol>
97 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]98 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
99 Global Variable</a></li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]100 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
101 Global Variable</a></li>
102 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
103 Global Variable</a></li>
104 </ol>
105 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]106 <li><a href="#instref">Instruction Reference</a>
107 <ol>
108 <li><a href="#terminators">Terminator Instructions</a>
109 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]110 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
111 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]112 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
113 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]114 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]115 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]116 </ol>
117 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]118 <li><a href="#binaryops">Binary Operations</a>
119 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]120 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]121 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]122 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]123 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]124 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]125 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]126 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
127 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
128 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]129 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
130 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
131 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]132 </ol>
133 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]134 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
135 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]136 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
137 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
138 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]139 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]140 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]141 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]142 </ol>
143 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]144 <li><a href="#vectorops">Vector Operations</a>
145 <ol>
146 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
147 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
148 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]149 </ol>
150 </li>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]151 <li><a href="#aggregateops">Aggregate Operations</a>
152 <ol>
153 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
154 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
155 </ol>
156 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]157 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]158 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]159 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
160 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
161 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]162 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
163 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
164 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]165 </ol>
166 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]167 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]168 <ol>
169 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
170 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
171 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
172 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
173 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]174 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
175 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
176 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
177 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]178 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
179 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]180 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]181 </ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]182 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]183 <li><a href="#otherops">Other Operations</a>
184 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]185 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
186 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]187 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]188 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]189 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]190 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]191 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]192 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]193 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]194 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]195 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]196 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]197 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
198 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]199 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
200 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
201 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]202 </ol>
203 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]204 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
205 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]206 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
207 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
208 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]209 </ol>
210 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]211 <li><a href="#int_codegen">Code Generator Intrinsics</a>
212 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]213 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
214 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
215 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
216 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
217 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
218 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
219 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]220 </ol>
221 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]222 <li><a href="#int_libc">Standard C Library Intrinsics</a>
223 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]224 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
225 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
226 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
227 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
228 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]229 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
230 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
231 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]232 </ol>
233 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]234 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]235 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]236 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]237 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
238 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
239 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]240 </ol>
241 </li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]242 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
243 <ol>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]244 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
245 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
246 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
247 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
248 <li><a href="#int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]249 <li><a href="#int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]250 </ol>
251 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]252 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]253 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]254 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]255 <ol>
256 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]257 </ol>
258 </li>
Bill Wendling3c44f5b2008-11-18 22:10:53 +0000[diff] [blame]259 <li><a href="#int_atomics">Atomic intrinsics</a>
260 <ol>
261 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
262 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
263 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
264 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
265 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
266 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
267 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
268 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
269 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
270 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
271 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
272 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
273 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
274 </ol>
275 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]276 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]277 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]278 <li><a href="#int_var_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]279 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]280 <li><a href="#int_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]281 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]282 <li><a href="#int_trap">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]283 '<tt>llvm.trap</tt>' Intrinsic</a></li>
284 <li><a href="#int_stackprotector">
285 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]286 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]287 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]288 </ol>
289 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]290</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]291
292<div class="doc_author">
293 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
294 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]295</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]296
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]297<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]298<div class="doc_section"> <a name="abstract">Abstract </a></div>
299<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]300
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]301<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]302
303<p>This document is a reference manual for the LLVM assembly language. LLVM is
304 a Static Single Assignment (SSA) based representation that provides type
305 safety, low-level operations, flexibility, and the capability of representing
306 'all' high-level languages cleanly. It is the common code representation
307 used throughout all phases of the LLVM compilation strategy.</p>
308
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]309</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]310
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]311<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]312<div class="doc_section"> <a name="introduction">Introduction</a> </div>
313<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]314
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]315<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]316
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]317<p>The LLVM code representation is designed to be used in three different forms:
318 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
319 for fast loading by a Just-In-Time compiler), and as a human readable
320 assembly language representation. This allows LLVM to provide a powerful
321 intermediate representation for efficient compiler transformations and
322 analysis, while providing a natural means to debug and visualize the
323 transformations. The three different forms of LLVM are all equivalent. This
324 document describes the human readable representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]325
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]326<p>The LLVM representation aims to be light-weight and low-level while being
327 expressive, typed, and extensible at the same time. It aims to be a
328 "universal IR" of sorts, by being at a low enough level that high-level ideas
329 may be cleanly mapped to it (similar to how microprocessors are "universal
330 IR's", allowing many source languages to be mapped to them). By providing
331 type information, LLVM can be used as the target of optimizations: for
332 example, through pointer analysis, it can be proven that a C automatic
333 variable is never accessed outside of the current function... allowing it to
334 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]335
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]336</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]337
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]338<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]339<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]340
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]341<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]342
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]343<p>It is important to note that this document describes 'well formed' LLVM
344 assembly language. There is a difference between what the parser accepts and
345 what is considered 'well formed'. For example, the following instruction is
346 syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]347
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]348<div class="doc_code">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]349<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]350%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]351</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]352</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]353
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]354<p>...because the definition of <tt>%x</tt> does not dominate all of its
355 uses. The LLVM infrastructure provides a verification pass that may be used
356 to verify that an LLVM module is well formed. This pass is automatically run
357 by the parser after parsing input assembly and by the optimizer before it
358 outputs bitcode. The violations pointed out by the verifier pass indicate
359 bugs in transformation passes or input to the parser.</p>
360
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]361</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]362
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]363<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]364
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]365<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]366<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]367<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]368
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]369<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]370
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]371<p>LLVM identifiers come in two basic types: global and local. Global
372 identifiers (functions, global variables) begin with the <tt>'@'</tt>
373 character. Local identifiers (register names, types) begin with
374 the <tt>'%'</tt> character. Additionally, there are three different formats
375 for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]376
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]377<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]378 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]379 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
380 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
381 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
382 other characters in their names can be surrounded with quotes. Special
383 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
384 ASCII code for the character in hexadecimal. In this way, any character
385 can be used in a name value, even quotes themselves.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]386
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]387 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]388 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]389
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]390 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]391 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]392</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]393
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]394<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]395 don't need to worry about name clashes with reserved words, and the set of
396 reserved words may be expanded in the future without penalty. Additionally,
397 unnamed identifiers allow a compiler to quickly come up with a temporary
398 variable without having to avoid symbol table conflicts.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]399
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]400<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]401 languages. There are keywords for different opcodes
402 ('<tt><a href="#i_add">add</a></tt>',
403 '<tt><a href="#i_bitcast">bitcast</a></tt>',
404 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
405 ('<tt><a href="#t_void">void</a></tt>',
406 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
407 reserved words cannot conflict with variable names, because none of them
408 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]409
410<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]411 '<tt>%X</tt>' by 8:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]412
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]413<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]414
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]415<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]416<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]417%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]418</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]419</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]420
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]421<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]422
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]423<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]424<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]425%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]426</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]427</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]428
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]429<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]430
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]431<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]432<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]433<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
434<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
435%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]436</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]437</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]438
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]439<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
440 lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]441
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]442<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]443 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]444 line.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]445
446 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]447 assigned to a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]448
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]449 <li>Unnamed temporaries are numbered sequentially</li>
450</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]451
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]452<p>...and it also shows a convention that we follow in this document. When
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]453 demonstrating instructions, we will follow an instruction with a comment that
454 defines the type and name of value produced. Comments are shown in italic
455 text.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]456
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]457</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]458
459<!-- *********************************************************************** -->
460<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
461<!-- *********************************************************************** -->
462
463<!-- ======================================================================= -->
464<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
465</div>
466
467<div class="doc_text">
468
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]469<p>LLVM programs are composed of "Module"s, each of which is a translation unit
470 of the input programs. Each module consists of functions, global variables,
471 and symbol table entries. Modules may be combined together with the LLVM
472 linker, which merges function (and global variable) definitions, resolves
473 forward declarations, and merges symbol table entries. Here is an example of
474 the "hello world" module:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]475
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]476<div class="doc_code">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]477<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]478<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
479 href="#globalvars">constant</a> <a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]480
481<i>; External declaration of the puts function</i>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]482<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]483
484<i>; Definition of main function</i>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]485define i32 @main() { <i>; i32()* </i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]486 <i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]487 %cast210 = <a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]488 href="#i_getelementptr">getelementptr</a> [13 x i8]* @.LC0, i64 0, i64 0 <i>; i8 *</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]489
490 <i>; Call puts function to write out the string to stdout...</i>
491 <a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]492 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]493 <a
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]494 href="#i_ret">ret</a> i32 0<br>}<br>
495</pre>
496</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]497
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]498<p>This example is made up of a <a href="#globalvars">global variable</a> named
499 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function, and
500 a <a href="#functionstructure">function definition</a> for
501 "<tt>main</tt>".</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]502
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]503<p>In general, a module is made up of a list of global values, where both
504 functions and global variables are global values. Global values are
505 represented by a pointer to a memory location (in this case, a pointer to an
506 array of char, and a pointer to a function), and have one of the
507 following <a href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]508
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]509</div>
510
511<!-- ======================================================================= -->
512<div class="doc_subsection">
513 <a name="linkage">Linkage Types</a>
514</div>
515
516<div class="doc_text">
517
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]518<p>All Global Variables and Functions have one of the following types of
519 linkage:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]520
521<dl>
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]522 <dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]523 <dd>Global values with private linkage are only directly accessible by objects
524 in the current module. In particular, linking code into a module with an
525 private global value may cause the private to be renamed as necessary to
526 avoid collisions. Because the symbol is private to the module, all
527 references can be updated. This doesn't show up in any symbol table in the
528 object file.</dd>
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]529
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]530 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt>: </dt>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]531 <dd>Similar to private, but the symbol is passed through the assembler and
Chris Lattnere1eaf912009-08-24 04:32:16 +0000[diff] [blame^]532 removed by the linker after evaluation. Note that (unlike private
533 symbols) linker_private symbols are subject to coalescing by the linker:
534 weak symbols get merged and redefinitions are rejected. However, unlike
535 normal strong symbols, they are removed by the linker from the final
536 linked image (executable or dynamic library).</dd>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]537
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]538 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]539 <dd>Similar to private, but the value shows as a local symbol
540 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
541 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]542
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]543 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt>: </dt>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]544 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]545 into the object file corresponding to the LLVM module. They exist to
546 allow inlining and other optimizations to take place given knowledge of
547 the definition of the global, which is known to be somewhere outside the
548 module. Globals with <tt>available_externally</tt> linkage are allowed to
549 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
550 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]551
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]552 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]553 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]554 the same name when linkage occurs. This is typically used to implement
555 inline functions, templates, or other code which must be generated in each
556 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
557 allowed to be discarded.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]558
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]559 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]560 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
561 <tt>linkonce</tt> linkage, except that unreferenced globals with
562 <tt>weak</tt> linkage may not be discarded. This is used for globals that
563 are declared "weak" in C source code.</dd>
564
565 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
566 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
567 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
568 global scope.
569 Symbols with "<tt>common</tt>" linkage are merged in the same way as
570 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]571 <tt>common</tt> symbols may not have an explicit section,
572 must have a zero initializer, and may not be marked '<a
573 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
574 have common linkage.</dd>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]575
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]576
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]577 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]578 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]579 pointer to array type. When two global variables with appending linkage
580 are linked together, the two global arrays are appended together. This is
581 the LLVM, typesafe, equivalent of having the system linker append together
582 "sections" with identical names when .o files are linked.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]583
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]584 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]585 <dd>The semantics of this linkage follow the ELF object file model: the symbol
586 is weak until linked, if not linked, the symbol becomes null instead of
587 being an undefined reference.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]588
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]589 <dt><tt><b><a name="linkage_linkonce">linkonce_odr</a></b></tt>: </dt>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]590 <dt><tt><b><a name="linkage_weak">weak_odr</a></b></tt>: </dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]591 <dd>Some languages allow differing globals to be merged, such as two functions
592 with different semantics. Other languages, such as <tt>C++</tt>, ensure
593 that only equivalent globals are ever merged (the "one definition rule" -
594 "ODR"). Such languages can use the <tt>linkonce_odr</tt>
595 and <tt>weak_odr</tt> linkage types to indicate that the global will only
596 be merged with equivalent globals. These linkage types are otherwise the
597 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]598
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]599 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]600 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]601 visible, meaning that it participates in linkage and can be used to
602 resolve external symbol references.</dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]603</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]604
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]605<p>The next two types of linkage are targeted for Microsoft Windows platform
606 only. They are designed to support importing (exporting) symbols from (to)
607 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]608
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]609<dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]610 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]611 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]612 or variable via a global pointer to a pointer that is set up by the DLL
613 exporting the symbol. On Microsoft Windows targets, the pointer name is
614 formed by combining <code>__imp_</code> and the function or variable
615 name.</dd>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]616
617 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]618 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]619 pointer to a pointer in a DLL, so that it can be referenced with the
620 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
621 name is formed by combining <code>__imp_</code> and the function or
622 variable name.</dd>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]623</dl>
624
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]625<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
626 another module defined a "<tt>.LC0</tt>" variable and was linked with this
627 one, one of the two would be renamed, preventing a collision. Since
628 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
629 declarations), they are accessible outside of the current module.</p>
630
631<p>It is illegal for a function <i>declaration</i> to have any linkage type
632 other than "externally visible", <tt>dllimport</tt>
633 or <tt>extern_weak</tt>.</p>
634
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]635<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]636 or <tt>weak_odr</tt> linkages.</p>
637
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]638</div>
639
640<!-- ======================================================================= -->
641<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]642 <a name="callingconv">Calling Conventions</a>
643</div>
644
645<div class="doc_text">
646
647<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]648 and <a href="#i_invoke">invokes</a> can all have an optional calling
649 convention specified for the call. The calling convention of any pair of
650 dynamic caller/callee must match, or the behavior of the program is
651 undefined. The following calling conventions are supported by LLVM, and more
652 may be added in the future:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]653
654<dl>
655 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]656 <dd>This calling convention (the default if no other calling convention is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]657 specified) matches the target C calling conventions. This calling
658 convention supports varargs function calls and tolerates some mismatch in
659 the declared prototype and implemented declaration of the function (as
660 does normal C).</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]661
662 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]663 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]664 (e.g. by passing things in registers). This calling convention allows the
665 target to use whatever tricks it wants to produce fast code for the
666 target, without having to conform to an externally specified ABI
667 (Application Binary Interface). Implementations of this convention should
668 allow arbitrary <a href="CodeGenerator.html#tailcallopt">tail call
669 optimization</a> to be supported. This calling convention does not
670 support varargs and requires the prototype of all callees to exactly match
671 the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]672
673 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]674 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]675 as possible under the assumption that the call is not commonly executed.
676 As such, these calls often preserve all registers so that the call does
677 not break any live ranges in the caller side. This calling convention
678 does not support varargs and requires the prototype of all callees to
679 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]680
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]681 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]682 <dd>Any calling convention may be specified by number, allowing
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]683 target-specific calling conventions to be used. Target specific calling
684 conventions start at 64.</dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]685</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]686
687<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]688 support Pascal conventions or any other well-known target-independent
689 convention.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]690
691</div>
692
693<!-- ======================================================================= -->
694<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]695 <a name="visibility">Visibility Styles</a>
696</div>
697
698<div class="doc_text">
699
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]700<p>All Global Variables and Functions have one of the following visibility
701 styles:</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]702
703<dl>
704 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]705 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]706 that the declaration is visible to other modules and, in shared libraries,
707 means that the declared entity may be overridden. On Darwin, default
708 visibility means that the declaration is visible to other modules. Default
709 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]710
711 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]712 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]713 object if they are in the same shared object. Usually, hidden visibility
714 indicates that the symbol will not be placed into the dynamic symbol
715 table, so no other module (executable or shared library) can reference it
716 directly.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]717
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]718 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]719 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]720 the dynamic symbol table, but that references within the defining module
721 will bind to the local symbol. That is, the symbol cannot be overridden by
722 another module.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]723</dl>
724
725</div>
726
727<!-- ======================================================================= -->
728<div class="doc_subsection">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]729 <a name="namedtypes">Named Types</a>
730</div>
731
732<div class="doc_text">
733
734<p>LLVM IR allows you to specify name aliases for certain types. This can make
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]735 it easier to read the IR and make the IR more condensed (particularly when
736 recursive types are involved). An example of a name specification is:</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]737
738<div class="doc_code">
739<pre>
740%mytype = type { %mytype*, i32 }
741</pre>
742</div>
743
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]744<p>You may give a name to any <a href="#typesystem">type</a> except
745 "<a href="t_void">void</a>". Type name aliases may be used anywhere a type
746 is expected with the syntax "%mytype".</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]747
748<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]749 and that you can therefore specify multiple names for the same type. This
750 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
751 uses structural typing, the name is not part of the type. When printing out
752 LLVM IR, the printer will pick <em>one name</em> to render all types of a
753 particular shape. This means that if you have code where two different
754 source types end up having the same LLVM type, that the dumper will sometimes
755 print the "wrong" or unexpected type. This is an important design point and
756 isn't going to change.</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]757
758</div>
759
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]760<!-- ======================================================================= -->
761<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]762 <a name="globalvars">Global Variables</a>
763</div>
764
765<div class="doc_text">
766
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]767<p>Global variables define regions of memory allocated at compilation time
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]768 instead of run-time. Global variables may optionally be initialized, may
769 have an explicit section to be placed in, and may have an optional explicit
770 alignment specified. A variable may be defined as "thread_local", which
771 means that it will not be shared by threads (each thread will have a
772 separated copy of the variable). A variable may be defined as a global
773 "constant," which indicates that the contents of the variable
774 will <b>never</b> be modified (enabling better optimization, allowing the
775 global data to be placed in the read-only section of an executable, etc).
776 Note that variables that need runtime initialization cannot be marked
777 "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]778
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]779<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
780 constant, even if the final definition of the global is not. This capability
781 can be used to enable slightly better optimization of the program, but
782 requires the language definition to guarantee that optimizations based on the
783 'constantness' are valid for the translation units that do not include the
784 definition.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]785
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]786<p>As SSA values, global variables define pointer values that are in scope
787 (i.e. they dominate) all basic blocks in the program. Global variables
788 always define a pointer to their "content" type because they describe a
789 region of memory, and all memory objects in LLVM are accessed through
790 pointers.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]791
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]792<p>A global variable may be declared to reside in a target-specific numbered
793 address space. For targets that support them, address spaces may affect how
794 optimizations are performed and/or what target instructions are used to
795 access the variable. The default address space is zero. The address space
796 qualifier must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]797
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]798<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]799 supports it, it will emit globals to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]800
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]801<p>An explicit alignment may be specified for a global. If not present, or if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]802 the alignment is set to zero, the alignment of the global is set by the
803 target to whatever it feels convenient. If an explicit alignment is
804 specified, the global is forced to have at least that much alignment. All
805 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]806
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]807<p>For example, the following defines a global in a numbered address space with
808 an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]809
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]810<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]811<pre>
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]812@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]813</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]814</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]815
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]816</div>
817
818
819<!-- ======================================================================= -->
820<div class="doc_subsection">
821 <a name="functionstructure">Functions</a>
822</div>
823
824<div class="doc_text">
825
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]826<p>LLVM function definitions consist of the "<tt>define</tt>" keyord, an
827 optional <a href="#linkage">linkage type</a>, an optional
828 <a href="#visibility">visibility style</a>, an optional
829 <a href="#callingconv">calling convention</a>, a return type, an optional
830 <a href="#paramattrs">parameter attribute</a> for the return type, a function
831 name, a (possibly empty) argument list (each with optional
832 <a href="#paramattrs">parameter attributes</a>), optional
833 <a href="#fnattrs">function attributes</a>, an optional section, an optional
834 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
835 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]836
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]837<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
838 optional <a href="#linkage">linkage type</a>, an optional
839 <a href="#visibility">visibility style</a>, an optional
840 <a href="#callingconv">calling convention</a>, a return type, an optional
841 <a href="#paramattrs">parameter attribute</a> for the return type, a function
842 name, a possibly empty list of arguments, an optional alignment, and an
843 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]844
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]845<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]846 (Control Flow Graph) for the function. Each basic block may optionally start
847 with a label (giving the basic block a symbol table entry), contains a list
848 of instructions, and ends with a <a href="#terminators">terminator</a>
849 instruction (such as a branch or function return).</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]850
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]851<p>The first basic block in a function is special in two ways: it is immediately
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]852 executed on entrance to the function, and it is not allowed to have
853 predecessor basic blocks (i.e. there can not be any branches to the entry
854 block of a function). Because the block can have no predecessors, it also
855 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]856
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]857<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]858 supports it, it will emit functions to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]859
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]860<p>An explicit alignment may be specified for a function. If not present, or if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]861 the alignment is set to zero, the alignment of the function is set by the
862 target to whatever it feels convenient. If an explicit alignment is
863 specified, the function is forced to have at least that much alignment. All
864 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]865
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]866<h5>Syntax:</h5>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]867<div class="doc_code">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]868<pre>
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]869define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]870 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
871 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
872 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
873 [<a href="#gc">gc</a>] { ... }
874</pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]875</div>
876
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]877</div>
878
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]879<!-- ======================================================================= -->
880<div class="doc_subsection">
881 <a name="aliasstructure">Aliases</a>
882</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]883
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]884<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]885
886<p>Aliases act as "second name" for the aliasee value (which can be either
887 function, global variable, another alias or bitcast of global value). Aliases
888 may have an optional <a href="#linkage">linkage type</a>, and an
889 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]890
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]891<h5>Syntax:</h5>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]892<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]893<pre>
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]894@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]895</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]896</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]897
898</div>
899
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]900<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]901<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]902
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]903<div class="doc_text">
904
905<p>The return type and each parameter of a function type may have a set of
906 <i>parameter attributes</i> associated with them. Parameter attributes are
907 used to communicate additional information about the result or parameters of
908 a function. Parameter attributes are considered to be part of the function,
909 not of the function type, so functions with different parameter attributes
910 can have the same function type.</p>
911
912<p>Parameter attributes are simple keywords that follow the type specified. If
913 multiple parameter attributes are needed, they are space separated. For
914 example:</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]915
916<div class="doc_code">
917<pre>
Nick Lewyckyb6a7d252009-02-15 23:06:14 +0000[diff] [blame]918declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]919declare i32 @atoi(i8 zeroext)
920declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]921</pre>
922</div>
923
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]924<p>Note that any attributes for the function result (<tt>nounwind</tt>,
925 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]926
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]927<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]928
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]929<dl>
930 <dt><tt>zeroext</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]931 <dd>This indicates to the code generator that the parameter or return value
932 should be zero-extended to a 32-bit value by the caller (for a parameter)
933 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]934
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]935 <dt><tt>signext</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]936 <dd>This indicates to the code generator that the parameter or return value
937 should be sign-extended to a 32-bit value by the caller (for a parameter)
938 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]939
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]940 <dt><tt>inreg</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]941 <dd>This indicates that this parameter or return value should be treated in a
942 special target-dependent fashion during while emitting code for a function
943 call or return (usually, by putting it in a register as opposed to memory,
944 though some targets use it to distinguish between two different kinds of
945 registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]946
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]947 <dt><tt><a name="byval">byval</a></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]948 <dd>This indicates that the pointer parameter should really be passed by value
949 to the function. The attribute implies that a hidden copy of the pointee
950 is made between the caller and the callee, so the callee is unable to
951 modify the value in the callee. This attribute is only valid on LLVM
952 pointer arguments. It is generally used to pass structs and arrays by
953 value, but is also valid on pointers to scalars. The copy is considered
954 to belong to the caller not the callee (for example,
955 <tt><a href="#readonly">readonly</a></tt> functions should not write to
956 <tt>byval</tt> parameters). This is not a valid attribute for return
957 values. The byval attribute also supports specifying an alignment with
958 the align attribute. This has a target-specific effect on the code
959 generator that usually indicates a desired alignment for the synthesized
960 stack slot.</dd>
961
962 <dt><tt>sret</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]963 <dd>This indicates that the pointer parameter specifies the address of a
964 structure that is the return value of the function in the source program.
965 This pointer must be guaranteed by the caller to be valid: loads and
966 stores to the structure may be assumed by the callee to not to trap. This
967 may only be applied to the first parameter. This is not a valid attribute
968 for return values. </dd>
969
970 <dt><tt>noalias</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]971 <dd>This indicates that the pointer does not alias any global or any other
972 parameter. The caller is responsible for ensuring that this is the
973 case. On a function return value, <tt>noalias</tt> additionally indicates
974 that the pointer does not alias any other pointers visible to the
975 caller. For further details, please see the discussion of the NoAlias
976 response in
977 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
978 analysis</a>.</dd>
979
980 <dt><tt>nocapture</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]981 <dd>This indicates that the callee does not make any copies of the pointer
982 that outlive the callee itself. This is not a valid attribute for return
983 values.</dd>
984
985 <dt><tt>nest</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]986 <dd>This indicates that the pointer parameter can be excised using the
987 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
988 attribute for return values.</dd>
989</dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]990
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]991</div>
992
993<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]994<div class="doc_subsection">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]995 <a name="gc">Garbage Collector Names</a>
996</div>
997
998<div class="doc_text">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]999
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1000<p>Each function may specify a garbage collector name, which is simply a
1001 string:</p>
1002
1003<div class="doc_code">
1004<pre>
1005define void @f() gc "name" { ...
1006</pre>
1007</div>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1008
1009<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1010 collector which will cause the compiler to alter its output in order to
1011 support the named garbage collection algorithm.</p>
1012
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1013</div>
1014
1015<!-- ======================================================================= -->
1016<div class="doc_subsection">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1017 <a name="fnattrs">Function Attributes</a>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1018</div>
1019
1020<div class="doc_text">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1021
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1022<p>Function attributes are set to communicate additional information about a
1023 function. Function attributes are considered to be part of the function, not
1024 of the function type, so functions with different parameter attributes can
1025 have the same function type.</p>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1026
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1027<p>Function attributes are simple keywords that follow the type specified. If
1028 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1029
1030<div class="doc_code">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1031<pre>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1032define void @f() noinline { ... }
1033define void @f() alwaysinline { ... }
1034define void @f() alwaysinline optsize { ... }
1035define void @f() optsize
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1036</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1037</div>
1038
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1039<dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1040 <dt><tt>alwaysinline</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1041 <dd>This attribute indicates that the inliner should attempt to inline this
1042 function into callers whenever possible, ignoring any active inlining size
1043 threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1044
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1045 <dt><tt>noinline</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1046 <dd>This attribute indicates that the inliner should never inline this
1047 function in any situation. This attribute may not be used together with
1048 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1049
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1050 <dt><tt>optsize</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1051 <dd>This attribute suggests that optimization passes and code generator passes
1052 make choices that keep the code size of this function low, and otherwise
1053 do optimizations specifically to reduce code size.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1054
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1055 <dt><tt>noreturn</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1056 <dd>This function attribute indicates that the function never returns
1057 normally. This produces undefined behavior at runtime if the function
1058 ever does dynamically return.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1059
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1060 <dt><tt>nounwind</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1061 <dd>This function attribute indicates that the function never returns with an
1062 unwind or exceptional control flow. If the function does unwind, its
1063 runtime behavior is undefined.</dd>
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1064
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1065 <dt><tt>readnone</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1066 <dd>This attribute indicates that the function computes its result (or decides
1067 to unwind an exception) based strictly on its arguments, without
1068 dereferencing any pointer arguments or otherwise accessing any mutable
1069 state (e.g. memory, control registers, etc) visible to caller functions.
1070 It does not write through any pointer arguments
1071 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1072 changes any state visible to callers. This means that it cannot unwind
1073 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1074 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel5d96fda2009-06-12 19:45:19 +0000[diff] [blame]1075
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1076 <dt><tt><a name="readonly">readonly</a></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1077 <dd>This attribute indicates that the function does not write through any
1078 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1079 arguments) or otherwise modify any state (e.g. memory, control registers,
1080 etc) visible to caller functions. It may dereference pointer arguments
1081 and read state that may be set in the caller. A readonly function always
1082 returns the same value (or unwinds an exception identically) when called
1083 with the same set of arguments and global state. It cannot unwind an
1084 exception by calling the <tt>C++</tt> exception throwing methods, but may
1085 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc5ec8a72009-07-17 18:07:26 +0000[diff] [blame]1086
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1087 <dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1088 <dd>This attribute indicates that the function should emit a stack smashing
1089 protector. It is in the form of a "canary"&mdash;a random value placed on
1090 the stack before the local variables that's checked upon return from the
1091 function to see if it has been overwritten. A heuristic is used to
1092 determine if a function needs stack protectors or not.<br>
1093<br>
1094 If a function that has an <tt>ssp</tt> attribute is inlined into a
1095 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1096 function will have an <tt>ssp</tt> attribute.</dd>
1097
1098 <dt><tt>sspreq</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1099 <dd>This attribute indicates that the function should <em>always</em> emit a
1100 stack smashing protector. This overrides
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1101 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1102<br>
1103 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1104 function that doesn't have an <tt>sspreq</tt> attribute or which has
1105 an <tt>ssp</tt> attribute, then the resulting function will have
1106 an <tt>sspreq</tt> attribute.</dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1107
1108 <dt><tt>noredzone</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1109 <dd>This attribute indicates that the code generator should not use a red
1110 zone, even if the target-specific ABI normally permits it.</dd>
1111
1112 <dt><tt>noimplicitfloat</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1113 <dd>This attributes disables implicit floating point instructions.</dd>
1114
1115 <dt><tt>naked</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1116 <dd>This attribute disables prologue / epilogue emission for the function.
1117 This can have very system-specific consequences.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1118</dl>
1119
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1120</div>
1121
1122<!-- ======================================================================= -->
1123<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1124 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1125</div>
1126
1127<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1128
1129<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1130 the GCC "file scope inline asm" blocks. These blocks are internally
1131 concatenated by LLVM and treated as a single unit, but may be separated in
1132 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1133
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1134<div class="doc_code">
1135<pre>
1136module asm "inline asm code goes here"
1137module asm "more can go here"
1138</pre>
1139</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1140
1141<p>The strings can contain any character by escaping non-printable characters.
1142 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1143 for the number.</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1144
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1145<p>The inline asm code is simply printed to the machine code .s file when
1146 assembly code is generated.</p>
1147
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1148</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1149
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1150<!-- ======================================================================= -->
1151<div class="doc_subsection">
1152 <a name="datalayout">Data Layout</a>
1153</div>
1154
1155<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1156
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1157<p>A module may specify a target specific data layout string that specifies how
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1158 data is to be laid out in memory. The syntax for the data layout is
1159 simply:</p>
1160
1161<div class="doc_code">
1162<pre>
1163target datalayout = "<i>layout specification</i>"
1164</pre>
1165</div>
1166
1167<p>The <i>layout specification</i> consists of a list of specifications
1168 separated by the minus sign character ('-'). Each specification starts with
1169 a letter and may include other information after the letter to define some
1170 aspect of the data layout. The specifications accepted are as follows:</p>
1171
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1172<dl>
1173 <dt><tt>E</tt></dt>
1174 <dd>Specifies that the target lays out data in big-endian form. That is, the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1175 bits with the most significance have the lowest address location.</dd>
1176
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1177 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1178 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1179 the bits with the least significance have the lowest address
1180 location.</dd>
1181
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1182 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1183 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1184 <i>preferred</i> alignments. All sizes are in bits. Specifying
1185 the <i>pref</i> alignment is optional. If omitted, the
1186 preceding <tt>:</tt> should be omitted too.</dd>
1187
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1188 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1189 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1190 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1191
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1192 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1193 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1194 <i>size</i>.</dd>
1195
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1196 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1197 <dd>This specifies the alignment for a floating point type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1198 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1199 (double).</dd>
1200
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1201 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1202 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1203 <i>size</i>.</dd>
1204
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1205 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1206 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1207 <i>size</i>.</dd>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1208</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1209
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1210<p>When constructing the data layout for a given target, LLVM starts with a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1211 default set of specifications which are then (possibly) overriden by the
1212 specifications in the <tt>datalayout</tt> keyword. The default specifications
1213 are given in this list:</p>
1214
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1215<ul>
1216 <li><tt>E</tt> - big endian</li>
1217 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1218 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1219 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1220 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1221 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1222 <li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1223 alignment of 64-bits</li>
1224 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1225 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1226 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1227 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1228 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1229 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1230</ul>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1231
1232<p>When LLVM is determining the alignment for a given type, it uses the
1233 following rules:</p>
1234
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1235<ol>
1236 <li>If the type sought is an exact match for one of the specifications, that
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1237 specification is used.</li>
1238
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1239 <li>If no match is found, and the type sought is an integer type, then the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1240 smallest integer type that is larger than the bitwidth of the sought type
1241 is used. If none of the specifications are larger than the bitwidth then
1242 the the largest integer type is used. For example, given the default
1243 specifications above, the i7 type will use the alignment of i8 (next
1244 largest) while both i65 and i256 will use the alignment of i64 (largest
1245 specified).</li>
1246
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1247 <li>If no match is found, and the type sought is a vector type, then the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1248 largest vector type that is smaller than the sought vector type will be
1249 used as a fall back. This happens because &lt;128 x double&gt; can be
1250 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1251</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1252
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1253</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1254
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1255<!-- ======================================================================= -->
1256<div class="doc_subsection">
1257 <a name="pointeraliasing">Pointer Aliasing Rules</a>
1258</div>
1259
1260<div class="doc_text">
1261
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1262<p>Any memory access must be done through a pointer value associated
Andreas Bolka99a82052009-07-27 20:37:10 +0000[diff] [blame]1263with an address range of the memory access, otherwise the behavior
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1264is undefined. Pointer values are associated with address ranges
1265according to the following rules:</p>
1266
1267<ul>
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1268 <li>A pointer value formed from a
1269 <tt><a href="#i_getelementptr">getelementptr</a></tt> instruction
1270 is associated with the addresses associated with the first operand
1271 of the <tt>getelementptr</tt>.</li>
1272 <li>An address of a global variable is associated with the address
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1273 range of the variable's storage.</li>
1274 <li>The result value of an allocation instruction is associated with
1275 the address range of the allocated storage.</li>
1276 <li>A null pointer in the default address-space is associated with
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1277 no address.</li>
1278 <li>A pointer value formed by an
1279 <tt><a href="#i_inttoptr">inttoptr</a></tt> is associated with all
1280 address ranges of all pointer values that contribute (directly or
1281 indirectly) to the computation of the pointer's value.</li>
1282 <li>The result value of a
1283 <tt><a href="#i_bitcast">bitcast</a></tt> is associated with all
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1284 addresses associated with the operand of the <tt>bitcast</tt>.</li>
1285 <li>An integer constant other than zero or a pointer value returned
1286 from a function not defined within LLVM may be associated with address
1287 ranges allocated through mechanisms other than those provided by
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1288 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1289 allocated by mechanisms provided by LLVM.</li>
1290 </ul>
1291
1292<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1293<tt><a href="#i_load">load</a></tt> merely indicates the size and
1294alignment of the memory from which to load, as well as the
1295interpretation of the value. The first operand of a
1296<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1297and alignment of the store.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1298
1299<p>Consequently, type-based alias analysis, aka TBAA, aka
1300<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1301LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1302additional information which specialized optimization passes may use
1303to implement type-based alias analysis.</p>
1304
1305</div>
1306
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1307<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1308<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1309<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1310
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1311<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1312
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1313<p>The LLVM type system is one of the most important features of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1314 intermediate representation. Being typed enables a number of optimizations
1315 to be performed on the intermediate representation directly, without having
1316 to do extra analyses on the side before the transformation. A strong type
1317 system makes it easier to read the generated code and enables novel analyses
1318 and transformations that are not feasible to perform on normal three address
1319 code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1320
1321</div>
1322
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1323<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1324<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1325Classifications</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1326
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1327<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1328
1329<p>The types fall into a few useful classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1330
1331<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1332 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1333 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1334 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1335 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1336 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1337 </tr>
1338 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1339 <td><a href="#t_floating">floating point</a></td>
1340 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1341 </tr>
1342 <tr>
1343 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1344 <td><a href="#t_integer">integer</a>,
1345 <a href="#t_floating">floating point</a>,
1346 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1347 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1348 <a href="#t_struct">structure</a>,
1349 <a href="#t_array">array</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1350 <a href="#t_label">label</a>,
1351 <a href="#t_metadata">metadata</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1352 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1353 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1354 <tr>
1355 <td><a href="#t_primitive">primitive</a></td>
1356 <td><a href="#t_label">label</a>,
1357 <a href="#t_void">void</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1358 <a href="#t_floating">floating point</a>,
1359 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1360 </tr>
1361 <tr>
1362 <td><a href="#t_derived">derived</a></td>
1363 <td><a href="#t_integer">integer</a>,
1364 <a href="#t_array">array</a>,
1365 <a href="#t_function">function</a>,
1366 <a href="#t_pointer">pointer</a>,
1367 <a href="#t_struct">structure</a>,
1368 <a href="#t_pstruct">packed structure</a>,
1369 <a href="#t_vector">vector</a>,
1370 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1371 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1372 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1373 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1374</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1375
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1376<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1377 important. Values of these types are the only ones which can be produced by
1378 instructions, passed as arguments, or used as operands to instructions.</p>
1379
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1380</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1381
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1382<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1383<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1384
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1385<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1386
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1387<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1388 system.</p>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1389
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1390</div>
1391
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1392<!-- _______________________________________________________________________ -->
1393<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1394
1395<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1396
1397<table>
1398 <tbody>
1399 <tr><th>Type</th><th>Description</th></tr>
1400 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1401 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1402 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1403 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1404 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1405 </tbody>
1406</table>
1407
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1408</div>
1409
1410<!-- _______________________________________________________________________ -->
1411<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1412
1413<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1414
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1415<h5>Overview:</h5>
1416<p>The void type does not represent any value and has no size.</p>
1417
1418<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1419<pre>
1420 void
1421</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1422
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1423</div>
1424
1425<!-- _______________________________________________________________________ -->
1426<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1427
1428<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1429
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1430<h5>Overview:</h5>
1431<p>The label type represents code labels.</p>
1432
1433<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1434<pre>
1435 label
1436</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1437
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1438</div>
1439
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1440<!-- _______________________________________________________________________ -->
1441<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
1442
1443<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1444
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1445<h5>Overview:</h5>
1446<p>The metadata type represents embedded metadata. The only derived type that
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1447 may contain metadata is <tt>metadata*</tt> or a function type that returns or
1448 takes metadata typed parameters, but not pointer to metadata types.</p>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1449
1450<h5>Syntax:</h5>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1451<pre>
1452 metadata
1453</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1454
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1455</div>
1456
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1457
1458<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1459<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1460
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1461<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1462
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1463<p>The real power in LLVM comes from the derived types in the system. This is
1464 what allows a programmer to represent arrays, functions, pointers, and other
1465 useful types. Note that these derived types may be recursive: For example,
1466 it is possible to have a two dimensional array.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1467
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1468</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1469
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1470<!-- _______________________________________________________________________ -->
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1471<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1472
1473<div class="doc_text">
1474
1475<h5>Overview:</h5>
1476<p>The integer type is a very simple derived type that simply specifies an
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1477 arbitrary bit width for the integer type desired. Any bit width from 1 bit to
1478 2^23-1 (about 8 million) can be specified.</p>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1479
1480<h5>Syntax:</h5>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1481<pre>
1482 iN
1483</pre>
1484
1485<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1486 value.</p>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1487
1488<h5>Examples:</h5>
1489<table class="layout">
Nick Lewycky86c48642009-05-24 02:46:06 +0000[diff] [blame]1490 <tr class="layout">
1491 <td class="left"><tt>i1</tt></td>
1492 <td class="left">a single-bit integer.</td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1493 </tr>
Nick Lewycky86c48642009-05-24 02:46:06 +0000[diff] [blame]1494 <tr class="layout">
1495 <td class="left"><tt>i32</tt></td>
1496 <td class="left">a 32-bit integer.</td>
1497 </tr>
1498 <tr class="layout">
1499 <td class="left"><tt>i1942652</tt></td>
1500 <td class="left">a really big integer of over 1 million bits.</td>
1501 </tr>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1502</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1503
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1504<p>Note that the code generator does not yet support large integer types to be
1505 used as function return types. The specific limit on how large a return type
1506 the code generator can currently handle is target-dependent; currently it's
1507 often 64 bits for 32-bit targets and 128 bits for 64-bit targets.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1508
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1509</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1510
1511<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1512<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1513
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1514<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1515
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1516<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1517<p>The array type is a very simple derived type that arranges elements
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1518 sequentially in memory. The array type requires a size (number of elements)
1519 and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1520
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1521<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1522<pre>
1523 [&lt;# elements&gt; x &lt;elementtype&gt;]
1524</pre>
1525
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1526<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1527 be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1528
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1529<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1530<table class="layout">
1531 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1532 <td class="left"><tt>[40 x i32]</tt></td>
1533 <td class="left">Array of 40 32-bit integer values.</td>
1534 </tr>
1535 <tr class="layout">
1536 <td class="left"><tt>[41 x i32]</tt></td>
1537 <td class="left">Array of 41 32-bit integer values.</td>
1538 </tr>
1539 <tr class="layout">
1540 <td class="left"><tt>[4 x i8]</tt></td>
1541 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1542 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1543</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1544<p>Here are some examples of multidimensional arrays:</p>
1545<table class="layout">
1546 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1547 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1548 <td class="left">3x4 array of 32-bit integer values.</td>
1549 </tr>
1550 <tr class="layout">
1551 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1552 <td class="left">12x10 array of single precision floating point values.</td>
1553 </tr>
1554 <tr class="layout">
1555 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1556 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1557 </tr>
1558</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1559
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1560<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1561 length array. Normally, accesses past the end of an array are undefined in
1562 LLVM (e.g. it is illegal to access the 5th element of a 3 element array). As
1563 a special case, however, zero length arrays are recognized to be variable
1564 length. This allows implementation of 'pascal style arrays' with the LLVM
1565 type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1566
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1567<p>Note that the code generator does not yet support large aggregate types to be
1568 used as function return types. The specific limit on how large an aggregate
1569 return type the code generator can currently handle is target-dependent, and
1570 also dependent on the aggregate element types.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1571
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1572</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1573
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1574<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1575<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1576
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1577<div class="doc_text">
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1578
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1579<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1580<p>The function type can be thought of as a function signature. It consists of
1581 a return type and a list of formal parameter types. The return type of a
1582 function type is a scalar type, a void type, or a struct type. If the return
1583 type is a struct type then all struct elements must be of first class types,
1584 and the struct must have at least one element.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1585
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1586<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1587<pre>
1588 &lt;returntype list&gt; (&lt;parameter list&gt;)
1589</pre>
1590
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1591<p>...where '<tt>&lt;parameter list&gt;</tt>' is a comma-separated list of type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1592 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1593 which indicates that the function takes a variable number of arguments.
1594 Variable argument functions can access their arguments with
1595 the <a href="#int_varargs">variable argument handling intrinsic</a>
1596 functions. '<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1597 <a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1598
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1599<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1600<table class="layout">
1601 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1602 <td class="left"><tt>i32 (i32)</tt></td>
1603 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1604 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1605 </tr><tr class="layout">
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]1606 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1607 </tt></td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1608 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1609 an <tt>i16</tt> that should be sign extended and a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1610 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1611 <tt>float</tt>.
1612 </td>
1613 </tr><tr class="layout">
1614 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1615 <td class="left">A vararg function that takes at least one
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1616 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1617 which returns an integer. This is the signature for <tt>printf</tt> in
1618 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1619 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1620 </tr><tr class="layout">
1621 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukmanb0a57aa2008-11-27 06:41:20 +0000[diff] [blame]1622 <td class="left">A function taking an <tt>i32</tt>, returning two
1623 <tt>i32</tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1624 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1625 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1626</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1627
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1628</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1629
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1630<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1631<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1632
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1633<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1634
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1635<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1636<p>The structure type is used to represent a collection of data members together
1637 in memory. The packing of the field types is defined to match the ABI of the
1638 underlying processor. The elements of a structure may be any type that has a
1639 size.</p>
1640
1641<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1642 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1643 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1644
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1645<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1646<pre>
1647 { &lt;type list&gt; }
1648</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1649
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1650<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1651<table class="layout">
1652 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1653 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1654 <td class="left">A triple of three <tt>i32</tt> values</td>
1655 </tr><tr class="layout">
1656 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1657 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1658 second element is a <a href="#t_pointer">pointer</a> to a
1659 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1660 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1661 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1662</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1663
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1664<p>Note that the code generator does not yet support large aggregate types to be
1665 used as function return types. The specific limit on how large an aggregate
1666 return type the code generator can currently handle is target-dependent, and
1667 also dependent on the aggregate element types.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1668
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1669</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1670
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1671<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1672<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1673</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1674
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1675<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1676
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1677<h5>Overview:</h5>
1678<p>The packed structure type is used to represent a collection of data members
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1679 together in memory. There is no padding between fields. Further, the
1680 alignment of a packed structure is 1 byte. The elements of a packed
1681 structure may be any type that has a size.</p>
1682
1683<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1684 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1685 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1686
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1687<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1688<pre>
1689 &lt; { &lt;type list&gt; } &gt;
1690</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1691
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1692<h5>Examples:</h5>
1693<table class="layout">
1694 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1695 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1696 <td class="left">A triple of three <tt>i32</tt> values</td>
1697 </tr><tr class="layout">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1698 <td class="left">
1699<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1700 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1701 second element is a <a href="#t_pointer">pointer</a> to a
1702 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1703 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1704 </tr>
1705</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1706
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1707</div>
1708
1709<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1710<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1711
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1712<div class="doc_text">
1713
1714<h5>Overview:</h5>
1715<p>As in many languages, the pointer type represents a pointer or reference to
1716 another object, which must live in memory. Pointer types may have an optional
1717 address space attribute defining the target-specific numbered address space
1718 where the pointed-to object resides. The default address space is zero.</p>
1719
1720<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
1721 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1722
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1723<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1724<pre>
1725 &lt;type&gt; *
1726</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1727
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1728<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1729<table class="layout">
1730 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]1731 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1732 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1733 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1734 </tr>
1735 <tr class="layout">
1736 <td class="left"><tt>i32 (i32 *) *</tt></td>
1737 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1738 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1739 <tt>i32</tt>.</td>
1740 </tr>
1741 <tr class="layout">
1742 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1743 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1744 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1745 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1746</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1747
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1748</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1749
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1750<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1751<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1752
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1753<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1754
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1755<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1756<p>A vector type is a simple derived type that represents a vector of elements.
1757 Vector types are used when multiple primitive data are operated in parallel
1758 using a single instruction (SIMD). A vector type requires a size (number of
1759 elements) and an underlying primitive data type. Vectors must have a power
1760 of two length (1, 2, 4, 8, 16 ...). Vector types are considered
1761 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1762
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1763<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1764<pre>
1765 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1766</pre>
1767
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1768<p>The number of elements is a constant integer value; elementtype may be any
1769 integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1770
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1771<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1772<table class="layout">
1773 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1774 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1775 <td class="left">Vector of 4 32-bit integer values.</td>
1776 </tr>
1777 <tr class="layout">
1778 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1779 <td class="left">Vector of 8 32-bit floating-point values.</td>
1780 </tr>
1781 <tr class="layout">
1782 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1783 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1784 </tr>
1785</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1786
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1787<p>Note that the code generator does not yet support large vector types to be
1788 used as function return types. The specific limit on how large a vector
1789 return type codegen can currently handle is target-dependent; currently it's
1790 often a few times longer than a hardware vector register.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1791
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1792</div>
1793
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1794<!-- _______________________________________________________________________ -->
1795<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1796<div class="doc_text">
1797
1798<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1799<p>Opaque types are used to represent unknown types in the system. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1800 corresponds (for example) to the C notion of a forward declared structure
1801 type. In LLVM, opaque types can eventually be resolved to any type (not just
1802 a structure type).</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1803
1804<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1805<pre>
1806 opaque
1807</pre>
1808
1809<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1810<table class="layout">
1811 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1812 <td class="left"><tt>opaque</tt></td>
1813 <td class="left">An opaque type.</td>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1814 </tr>
1815</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1816
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1817</div>
1818
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1819<!-- ======================================================================= -->
1820<div class="doc_subsection">
1821 <a name="t_uprefs">Type Up-references</a>
1822</div>
1823
1824<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1825
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1826<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1827<p>An "up reference" allows you to refer to a lexically enclosing type without
1828 requiring it to have a name. For instance, a structure declaration may
1829 contain a pointer to any of the types it is lexically a member of. Example
1830 of up references (with their equivalent as named type declarations)
1831 include:</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1832
1833<pre>
Chris Lattner3060f5b2009-02-09 10:00:56 +0000[diff] [blame]1834 { \2 * } %x = type { %x* }
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1835 { \2 }* %y = type { %y }*
1836 \1* %z = type %z*
1837</pre>
1838
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1839<p>An up reference is needed by the asmprinter for printing out cyclic types
1840 when there is no declared name for a type in the cycle. Because the
1841 asmprinter does not want to print out an infinite type string, it needs a
1842 syntax to handle recursive types that have no names (all names are optional
1843 in llvm IR).</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1844
1845<h5>Syntax:</h5>
1846<pre>
1847 \&lt;level&gt;
1848</pre>
1849
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1850<p>The level is the count of the lexical type that is being referred to.</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1851
1852<h5>Examples:</h5>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1853<table class="layout">
1854 <tr class="layout">
1855 <td class="left"><tt>\1*</tt></td>
1856 <td class="left">Self-referential pointer.</td>
1857 </tr>
1858 <tr class="layout">
1859 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
1860 <td class="left">Recursive structure where the upref refers to the out-most
1861 structure.</td>
1862 </tr>
1863</table>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1864
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1865</div>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1866
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1867<!-- *********************************************************************** -->
1868<div class="doc_section"> <a name="constants">Constants</a> </div>
1869<!-- *********************************************************************** -->
1870
1871<div class="doc_text">
1872
1873<p>LLVM has several different basic types of constants. This section describes
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1874 them all and their syntax.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1875
1876</div>
1877
1878<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1879<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1880
1881<div class="doc_text">
1882
1883<dl>
1884 <dt><b>Boolean constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1885 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1886 constants of the <tt><a href="#t_primitive">i1</a></tt> type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1887
1888 <dt><b>Integer constants</b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1889 <dd>Standard integers (such as '4') are constants of
1890 the <a href="#t_integer">integer</a> type. Negative numbers may be used
1891 with integer types.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1892
1893 <dt><b>Floating point constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1894 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1895 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
1896 notation (see below). The assembler requires the exact decimal value of a
1897 floating-point constant. For example, the assembler accepts 1.25 but
1898 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1899 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1900
1901 <dt><b>Null pointer constants</b></dt>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1902 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1903 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1904</dl>
1905
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1906<p>The one non-intuitive notation for constants is the hexadecimal form of
1907 floating point constants. For example, the form '<tt>double
1908 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
1909 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
1910 constants are required (and the only time that they are generated by the
1911 disassembler) is when a floating point constant must be emitted but it cannot
1912 be represented as a decimal floating point number in a reasonable number of
1913 digits. For example, NaN's, infinities, and other special values are
1914 represented in their IEEE hexadecimal format so that assembly and disassembly
1915 do not cause any bits to change in the constants.</p>
1916
Dale Johannesenbd5e5a82009-02-11 22:14:51 +0000[diff] [blame]1917<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1918 represented using the 16-digit form shown above (which matches the IEEE754
1919 representation for double); float values must, however, be exactly
1920 representable as IEE754 single precision. Hexadecimal format is always used
1921 for long double, and there are three forms of long double. The 80-bit format
1922 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
1923 The 128-bit format used by PowerPC (two adjacent doubles) is represented
1924 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
1925 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
1926 currently supported target uses this format. Long doubles will only work if
1927 they match the long double format on your target. All hexadecimal formats
1928 are big-endian (sign bit at the left).</p>
1929
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1930</div>
1931
1932<!-- ======================================================================= -->
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]1933<div class="doc_subsection">
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]1934<a name="aggregateconstants"></a> <!-- old anchor -->
1935<a name="complexconstants">Complex Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1936</div>
1937
1938<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1939
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]1940<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1941 constants and smaller complex constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1942
1943<dl>
1944 <dt><b>Structure constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1945 <dd>Structure constants are represented with notation similar to structure
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1946 type definitions (a comma separated list of elements, surrounded by braces
1947 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1948 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
1949 Structure constants must have <a href="#t_struct">structure type</a>, and
1950 the number and types of elements must match those specified by the
1951 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1952
1953 <dt><b>Array constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1954 <dd>Array constants are represented with notation similar to array type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1955 definitions (a comma separated list of elements, surrounded by square
1956 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
1957 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
1958 the number and types of elements must match those specified by the
1959 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1960
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1961 <dt><b>Vector constants</b></dt>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1962 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1963 definitions (a comma separated list of elements, surrounded by
1964 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
1965 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
1966 have <a href="#t_vector">vector type</a>, and the number and types of
1967 elements must match those specified by the type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1968
1969 <dt><b>Zero initialization</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1970 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1971 value to zero of <em>any</em> type, including scalar and aggregate types.
1972 This is often used to avoid having to print large zero initializers
1973 (e.g. for large arrays) and is always exactly equivalent to using explicit
1974 zero initializers.</dd>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]1975
1976 <dt><b>Metadata node</b></dt>
Nick Lewycky1e8c7a62009-05-30 16:08:30 +0000[diff] [blame]1977 <dd>A metadata node is a structure-like constant with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1978 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
1979 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
1980 be interpreted as part of the instruction stream, metadata is a place to
1981 attach additional information such as debug info.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1982</dl>
1983
1984</div>
1985
1986<!-- ======================================================================= -->
1987<div class="doc_subsection">
1988 <a name="globalconstants">Global Variable and Function Addresses</a>
1989</div>
1990
1991<div class="doc_text">
1992
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1993<p>The addresses of <a href="#globalvars">global variables</a>
1994 and <a href="#functionstructure">functions</a> are always implicitly valid
1995 (link-time) constants. These constants are explicitly referenced when
1996 the <a href="#identifiers">identifier for the global</a> is used and always
1997 have <a href="#t_pointer">pointer</a> type. For example, the following is a
1998 legal LLVM file:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1999
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2000<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2001<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]2002@X = global i32 17
2003@Y = global i32 42
2004@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2005</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2006</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2007
2008</div>
2009
2010<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]2011<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2012<div class="doc_text">
2013
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2014<p>The string '<tt>undef</tt>' is recognized as a type-less constant that has no
2015 specific value. Undefined values may be of any type and be used anywhere a
2016 constant is permitted.</p>
2017
2018<p>Undefined values indicate to the compiler that the program is well defined no
2019 matter what value is used, giving the compiler more freedom to optimize.</p>
2020
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2021</div>
2022
2023<!-- ======================================================================= -->
2024<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
2025</div>
2026
2027<div class="doc_text">
2028
2029<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2030 to be used as constants. Constant expressions may be of
2031 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2032 operation that does not have side effects (e.g. load and call are not
2033 supported). The following is the syntax for constant expressions:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2034
2035<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2036 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2037 <dd>Truncate a constant to another type. The bit size of CST must be larger
2038 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2039
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2040 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2041 <dd>Zero extend a constant to another type. The bit size of CST must be
2042 smaller or equal to the bit size of TYPE. Both types must be
2043 integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2044
2045 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2046 <dd>Sign extend a constant to another type. The bit size of CST must be
2047 smaller or equal to the bit size of TYPE. Both types must be
2048 integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2049
2050 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2051 <dd>Truncate a floating point constant to another floating point type. The
2052 size of CST must be larger than the size of TYPE. Both types must be
2053 floating point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2054
2055 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2056 <dd>Floating point extend a constant to another type. The size of CST must be
2057 smaller or equal to the size of TYPE. Both types must be floating
2058 point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2059
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]2060 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2061 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2062 constant. TYPE must be a scalar or vector integer type. CST must be of
2063 scalar or vector floating point type. Both CST and TYPE must be scalars,
2064 or vectors of the same number of elements. If the value won't fit in the
2065 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2066
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2067 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2068 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2069 constant. TYPE must be a scalar or vector integer type. CST must be of
2070 scalar or vector floating point type. Both CST and TYPE must be scalars,
2071 or vectors of the same number of elements. If the value won't fit in the
2072 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2073
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2074 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2075 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2076 constant. TYPE must be a scalar or vector floating point type. CST must be
2077 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2078 vectors of the same number of elements. If the value won't fit in the
2079 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2080
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2081 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2082 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2083 constant. TYPE must be a scalar or vector floating point type. CST must be
2084 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2085 vectors of the same number of elements. If the value won't fit in the
2086 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2087
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2088 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
2089 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2090 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2091 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2092 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2093
2094 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2095 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2096 type. CST must be of integer type. The CST value is zero extended,
2097 truncated, or unchanged to make it fit in a pointer size. This one is
2098 <i>really</i> dangerous!</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2099
2100 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner03bbad62009-02-28 18:27:03 +0000[diff] [blame]2101 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2102 are the same as those for the <a href="#i_bitcast">bitcast
2103 instruction</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2104
2105 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]2106 <dt><b><tt>getelementptr inbounds ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2107 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2108 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2109 instruction, the index list may have zero or more indexes, which are
2110 required to make sense for the type of "CSTPTR".</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2111
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2112 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2113 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2114
2115 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
2116 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2117
2118 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
2119 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2120
2121 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2122 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2123 constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2124
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]2125 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2126 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2127 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2128
2129 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2130 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2131 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2132
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2133 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2134 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2135 be any of the <a href="#binaryops">binary</a>
2136 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2137 on operands are the same as those for the corresponding instruction
2138 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2139</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2140
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2141</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]2142
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2143<!-- ======================================================================= -->
2144<div class="doc_subsection"><a name="metadata">Embedded Metadata</a>
2145</div>
2146
2147<div class="doc_text">
2148
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2149<p>Embedded metadata provides a way to attach arbitrary data to the instruction
2150 stream without affecting the behaviour of the program. There are two
2151 metadata primitives, strings and nodes. All metadata has the
2152 <tt>metadata</tt> type and is identified in syntax by a preceding exclamation
2153 point ('<tt>!</tt>').</p>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2154
2155<p>A metadata string is a string surrounded by double quotes. It can contain
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2156 any character by escaping non-printable characters with "\xx" where "xx" is
2157 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2158
2159<p>Metadata nodes are represented with notation similar to structure constants
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2160 (a comma separated list of elements, surrounded by braces and preceeded by an
2161 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2162 10}</tt>".</p>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2163
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2164<p>A metadata node will attempt to track changes to the values it holds. In the
2165 event that a value is deleted, it will be replaced with a typeless
2166 "<tt>null</tt>", such as "<tt>metadata !{null, i32 10}</tt>".</p>
Nick Lewyckycb337992009-05-10 20:57:05 +0000[diff] [blame]2167
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2168<p>Optimizations may rely on metadata to provide additional information about
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2169 the program that isn't available in the instructions, or that isn't easily
2170 computable. Similarly, the code generator may expect a certain metadata
2171 format to be used to express debugging information.</p>
2172
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2173</div>
2174
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2175<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2176<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
2177<!-- *********************************************************************** -->
2178
2179<!-- ======================================================================= -->
2180<div class="doc_subsection">
2181<a name="inlineasm">Inline Assembler Expressions</a>
2182</div>
2183
2184<div class="doc_text">
2185
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2186<p>LLVM supports inline assembler expressions (as opposed
2187 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2188 a special value. This value represents the inline assembler as a string
2189 (containing the instructions to emit), a list of operand constraints (stored
2190 as a string), and a flag that indicates whether or not the inline asm
2191 expression has side effects. An example inline assembler expression is:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2192
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2193<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2194<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2195i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2196</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2197</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2198
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2199<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2200 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2201 have:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2202
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2203<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2204<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2205%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]2206</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2207</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2208
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2209<p>Inline asms with side effects not visible in the constraint list must be
2210 marked as having side effects. This is done through the use of the
2211 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2212
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2213<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2214<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2215call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2216</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2217</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2218
2219<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2220 documented here. Constraints on what can be done (e.g. duplication, moving,
2221 etc need to be documented). This is probably best done by reference to
2222 another document that covers inline asm from a holistic perspective.</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2223
2224</div>
2225
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2226
2227<!-- *********************************************************************** -->
2228<div class="doc_section">
2229 <a name="intrinsic_globals">Intrinsic Global Variables</a>
2230</div>
2231<!-- *********************************************************************** -->
2232
2233<p>LLVM has a number of "magic" global variables that contain data that affect
2234code generation or other IR semantics. These are documented here. All globals
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2235of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2236section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2237by LLVM.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2238
2239<!-- ======================================================================= -->
2240<div class="doc_subsection">
2241<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
2242</div>
2243
2244<div class="doc_text">
2245
2246<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2247href="#linkage_appending">appending linkage</a>. This array contains a list of
2248pointers to global variables and functions which may optionally have a pointer
2249cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2250
2251<pre>
2252 @X = global i8 4
2253 @Y = global i32 123
2254
2255 @llvm.used = appending global [2 x i8*] [
2256 i8* @X,
2257 i8* bitcast (i32* @Y to i8*)
2258 ], section "llvm.metadata"
2259</pre>
2260
2261<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2262compiler, assembler, and linker are required to treat the symbol as if there is
2263a reference to the global that it cannot see. For example, if a variable has
2264internal linkage and no references other than that from the <tt>@llvm.used</tt>
2265list, it cannot be deleted. This is commonly used to represent references from
2266inline asms and other things the compiler cannot "see", and corresponds to
2267"attribute((used))" in GNU C.</p>
2268
2269<p>On some targets, the code generator must emit a directive to the assembler or
2270object file to prevent the assembler and linker from molesting the symbol.</p>
2271
2272</div>
2273
2274<!-- ======================================================================= -->
2275<div class="doc_subsection">
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2276<a name="intg_compiler_used">The '<tt>llvm.compiler.used</tt>' Global Variable</a>
2277</div>
2278
2279<div class="doc_text">
2280
2281<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2282<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2283touching the symbol. On targets that support it, this allows an intelligent
2284linker to optimize references to the symbol without being impeded as it would be
2285by <tt>@llvm.used</tt>.</p>
2286
2287<p>This is a rare construct that should only be used in rare circumstances, and
2288should not be exposed to source languages.</p>
2289
2290</div>
2291
2292<!-- ======================================================================= -->
2293<div class="doc_subsection">
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2294<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
2295</div>
2296
2297<div class="doc_text">
2298
2299<p>TODO: Describe this.</p>
2300
2301</div>
2302
2303<!-- ======================================================================= -->
2304<div class="doc_subsection">
2305<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
2306</div>
2307
2308<div class="doc_text">
2309
2310<p>TODO: Describe this.</p>
2311
2312</div>
2313
2314
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2315<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2316<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
2317<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2318
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2319<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2320
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2321<p>The LLVM instruction set consists of several different classifications of
2322 instructions: <a href="#terminators">terminator
2323 instructions</a>, <a href="#binaryops">binary instructions</a>,
2324 <a href="#bitwiseops">bitwise binary instructions</a>,
2325 <a href="#memoryops">memory instructions</a>, and
2326 <a href="#otherops">other instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2327
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2328</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2329
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2330<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2331<div class="doc_subsection"> <a name="terminators">Terminator
2332Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2333
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2334<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2335
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2336<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2337 in a program ends with a "Terminator" instruction, which indicates which
2338 block should be executed after the current block is finished. These
2339 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2340 control flow, not values (the one exception being the
2341 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2342
2343<p>There are six different terminator instructions: the
2344 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2345 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2346 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
2347 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2348 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2349 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2350
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2351</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2352
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2353<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2354<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
2355Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2356
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2357<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2358
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2359<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2360<pre>
2361 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]2362 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2363</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2364
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2365<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2366<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2367 a value) from a function back to the caller.</p>
2368
2369<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2370 value and then causes control flow, and one that just causes control flow to
2371 occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2372
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2373<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2374<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2375 return value. The type of the return value must be a
2376 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2377
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2378<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2379 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2380 value or a return value with a type that does not match its type, or if it
2381 has a void return type and contains a '<tt>ret</tt>' instruction with a
2382 return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2383
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2384<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2385<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2386 the calling function's context. If the caller is a
2387 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2388 instruction after the call. If the caller was an
2389 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2390 the beginning of the "normal" destination block. If the instruction returns
2391 a value, that value shall set the call or invoke instruction's return
2392 value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2393
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2394<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2395<pre>
2396 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2397 ret void <i>; Return from a void function</i>
Bill Wendling0a4bbbf2009-02-28 22:12:54 +0000[diff] [blame]2398 ret { i32, i8 } { i32 4, i8 2 } <i>; Return a struct of values 4 and 2</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2399</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2400
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]2401<p>Note that the code generator does not yet fully support large
2402 return values. The specific sizes that are currently supported are
2403 dependent on the target. For integers, on 32-bit targets the limit
2404 is often 64 bits, and on 64-bit targets the limit is often 128 bits.
2405 For aggregate types, the current limits are dependent on the element
2406 types; for example targets are often limited to 2 total integer
2407 elements and 2 total floating-point elements.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2408
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2409</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2410<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2411<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2412
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2413<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2414
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2415<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2416<pre>
2417 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]2418</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2419
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2420<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2421<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
2422 different basic block in the current function. There are two forms of this
2423 instruction, corresponding to a conditional branch and an unconditional
2424 branch.</p>
2425
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2426<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2427<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
2428 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
2429 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
2430 target.</p>
2431
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2432<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2433<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2434 argument is evaluated. If the value is <tt>true</tt>, control flows to the
2435 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2436 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
2437
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2438<h5>Example:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2439<pre>
2440Test:
2441 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
2442 br i1 %cond, label %IfEqual, label %IfUnequal
2443IfEqual:
2444 <a href="#i_ret">ret</a> i32 1
2445IfUnequal:
2446 <a href="#i_ret">ret</a> i32 0
2447</pre>
2448
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2449</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2450
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2451<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2452<div class="doc_subsubsection">
2453 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2454</div>
2455
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2456<div class="doc_text">
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2457
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2458<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2459<pre>
2460 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2461</pre>
2462
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2463<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2464<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2465 several different places. It is a generalization of the '<tt>br</tt>'
2466 instruction, allowing a branch to occur to one of many possible
2467 destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2468
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2469<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2470<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2471 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
2472 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
2473 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2474
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2475<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2476<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2477 destinations. When the '<tt>switch</tt>' instruction is executed, this table
2478 is searched for the given value. If the value is found, control flow is
2479 transfered to the corresponding destination; otherwise, control flow is
2480 transfered to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2481
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2482<h5>Implementation:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2483<p>Depending on properties of the target machine and the particular
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2484 <tt>switch</tt> instruction, this instruction may be code generated in
2485 different ways. For example, it could be generated as a series of chained
2486 conditional branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2487
2488<h5>Example:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2489<pre>
2490 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2491 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2492 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2493
2494 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2495 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2496
2497 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2498 switch i32 %val, label %otherwise [ i32 0, label %onzero
2499 i32 1, label %onone
2500 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2501</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2502
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2503</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2504
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2505<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2506<div class="doc_subsubsection">
2507 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2508</div>
2509
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2510<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2511
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2512<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2513<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2514 &lt;result&gt; = invoke [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] &lt;ptr to function ty&gt; &lt;function ptr val&gt;(&lt;function args&gt;) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner76b8a332006-05-14 18:23:06 +0000[diff] [blame]2515 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2516</pre>
2517
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2518<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2519<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2520 function, with the possibility of control flow transfer to either the
2521 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
2522 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
2523 control flow will return to the "normal" label. If the callee (or any
2524 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
2525 instruction, control is interrupted and continued at the dynamically nearest
2526 "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2527
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2528<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2529<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2530
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2531<ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2532 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
2533 convention</a> the call should use. If none is specified, the call
2534 defaults to using C calling conventions.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2535
2536 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2537 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
2538 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2539
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2540 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2541 function value being invoked. In most cases, this is a direct function
2542 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
2543 off an arbitrary pointer to function value.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2544
2545 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2546 function to be invoked. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2547
2548 <li>'<tt>function args</tt>': argument list whose types match the function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2549 signature argument types. If the function signature indicates the
2550 function accepts a variable number of arguments, the extra arguments can
2551 be specified.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2552
2553 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2554 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2555
2556 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2557 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2558
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2559 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2560 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2561 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2562</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2563
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2564<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2565<p>This instruction is designed to operate as a standard
2566 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
2567 primary difference is that it establishes an association with a label, which
2568 is used by the runtime library to unwind the stack.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2569
2570<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2571 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2572 exception. Additionally, this is important for implementation of
2573 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2574
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2575<p>For the purposes of the SSA form, the definition of the value returned by the
2576 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
2577 block to the "normal" label. If the callee unwinds then no return value is
2578 available.</p>
Dan Gohmanf96a4992009-05-22 21:47:08 +0000[diff] [blame]2579
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2580<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2581<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2582 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2583 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2584 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2585 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2586</pre>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2587
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2588</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2589
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2590<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2591
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2592<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2593Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2594
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2595<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2596
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2597<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2598<pre>
2599 unwind
2600</pre>
2601
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2602<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2603<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2604 at the first callee in the dynamic call stack which used
2605 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
2606 This is primarily used to implement exception handling.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2607
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2608<h5>Semantics:</h5>
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]2609<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2610 immediately halt. The dynamic call stack is then searched for the
2611 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
2612 Once found, execution continues at the "exceptional" destination block
2613 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
2614 instruction in the dynamic call chain, undefined behavior results.</p>
2615
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2616</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2617
2618<!-- _______________________________________________________________________ -->
2619
2620<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2621Instruction</a> </div>
2622
2623<div class="doc_text">
2624
2625<h5>Syntax:</h5>
2626<pre>
2627 unreachable
2628</pre>
2629
2630<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2631<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2632 instruction is used to inform the optimizer that a particular portion of the
2633 code is not reachable. This can be used to indicate that the code after a
2634 no-return function cannot be reached, and other facts.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2635
2636<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2637<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2638
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2639</div>
2640
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2641<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2642<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2643
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2644<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2645
2646<p>Binary operators are used to do most of the computation in a program. They
2647 require two operands of the same type, execute an operation on them, and
2648 produce a single value. The operands might represent multiple data, as is
2649 the case with the <a href="#t_vector">vector</a> data type. The result value
2650 has the same type as its operands.</p>
2651
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2652<p>There are several different binary operators:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2653
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2654</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2655
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2656<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2657<div class="doc_subsubsection">
2658 <a name="i_add">'<tt>add</tt>' Instruction</a>
2659</div>
2660
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2661<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2662
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2663<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2664<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2665 &lt;result&gt; = add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]2666 &lt;result&gt; = nuw add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2667 &lt;result&gt; = nsw add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2668 &lt;result&gt; = nuw nsw add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2669</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2670
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2671<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2672<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2673
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2674<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2675<p>The two arguments to the '<tt>add</tt>' instruction must
2676 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2677 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2678
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2679<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2680<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2681
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2682<p>If the sum has unsigned overflow, the result returned is the mathematical
2683 result modulo 2<sup>n</sup>, where n is the bit width of the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2684
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2685<p>Because LLVM integers use a two's complement representation, this instruction
2686 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2687
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]2688<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2689 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2690 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
2691 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2692
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2693<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2694<pre>
2695 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2696</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2697
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2698</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2699
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2700<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2701<div class="doc_subsubsection">
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2702 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
2703</div>
2704
2705<div class="doc_text">
2706
2707<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2708<pre>
2709 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2710</pre>
2711
2712<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2713<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
2714
2715<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2716<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2717 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2718 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2719
2720<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2721<p>The value produced is the floating point sum of the two operands.</p>
2722
2723<h5>Example:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2724<pre>
2725 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
2726</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2727
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2728</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2729
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2730<!-- _______________________________________________________________________ -->
2731<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2732 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2733</div>
2734
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2735<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2736
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2737<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2738<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]2739 &lt;result&gt; = sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2740 &lt;result&gt; = nuw sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2741 &lt;result&gt; = nsw sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2742 &lt;result&gt; = nuw nsw sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2743</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2744
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2745<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2746<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2747 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2748
2749<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2750 '<tt>neg</tt>' instruction present in most other intermediate
2751 representations.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2752
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2753<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2754<p>The two arguments to the '<tt>sub</tt>' instruction must
2755 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2756 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2757
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2758<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2759<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2760
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2761<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2762 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
2763 result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2764
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2765<p>Because LLVM integers use a two's complement representation, this instruction
2766 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2767
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]2768<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2769 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2770 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
2771 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2772
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2773<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2774<pre>
2775 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2776 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2777</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2778
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2779</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2780
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2781<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2782<div class="doc_subsubsection">
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2783 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
2784</div>
2785
2786<div class="doc_text">
2787
2788<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2789<pre>
2790 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2791</pre>
2792
2793<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2794<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2795 operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2796
2797<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2798 '<tt>fneg</tt>' instruction present in most other intermediate
2799 representations.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2800
2801<h5>Arguments:</h5>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]2802<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2803 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2804 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2805
2806<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2807<p>The value produced is the floating point difference of the two operands.</p>
2808
2809<h5>Example:</h5>
2810<pre>
2811 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
2812 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
2813</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2814
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2815</div>
2816
2817<!-- _______________________________________________________________________ -->
2818<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2819 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2820</div>
2821
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2822<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2823
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2824<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2825<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]2826 &lt;result&gt; = mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2827 &lt;result&gt; = nuw mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2828 &lt;result&gt; = nsw mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2829 &lt;result&gt; = nuw nsw mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2830</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2831
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2832<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2833<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2834
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2835<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2836<p>The two arguments to the '<tt>mul</tt>' instruction must
2837 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2838 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2839
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2840<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2841<p>The value produced is the integer product of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2842
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2843<p>If the result of the multiplication has unsigned overflow, the result
2844 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
2845 width of the result.</p>
2846
2847<p>Because LLVM integers use a two's complement representation, and the result
2848 is the same width as the operands, this instruction returns the correct
2849 result for both signed and unsigned integers. If a full product
2850 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
2851 be sign-extended or zero-extended as appropriate to the width of the full
2852 product.</p>
2853
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]2854<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2855 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2856 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
2857 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2858
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2859<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2860<pre>
2861 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2862</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2863
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2864</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2865
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2866<!-- _______________________________________________________________________ -->
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2867<div class="doc_subsubsection">
2868 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
2869</div>
2870
2871<div class="doc_text">
2872
2873<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2874<pre>
2875 &lt;result&gt; = fmul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2876</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2877
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2878<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2879<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2880
2881<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2882<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2883 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2884 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2885
2886<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2887<p>The value produced is the floating point product of the two operands.</p>
2888
2889<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2890<pre>
2891 &lt;result&gt; = fmul float 4.0, %var <i>; yields {float}:result = 4.0 * %var</i>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2892</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2893
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2894</div>
2895
2896<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2897<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2898</a></div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2899
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2900<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2901
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2902<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2903<pre>
2904 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2905</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2906
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2907<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2908<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2909
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2910<h5>Arguments:</h5>
2911<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2912 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2913 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2914
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2915<h5>Semantics:</h5>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2916<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2917
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2918<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2919 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2920
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2921<p>Division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2922
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2923<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2924<pre>
2925 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2926</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2927
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2928</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2929
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2930<!-- _______________________________________________________________________ -->
2931<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2932</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2933
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2934<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2935
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2936<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2937<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2938 &lt;result&gt; = sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2939 &lt;result&gt; = exact sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2940</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2941
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2942<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2943<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2944
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2945<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2946<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2947 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2948 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2949
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2950<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2951<p>The value produced is the signed integer quotient of the two operands rounded
2952 towards zero.</p>
2953
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2954<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2955 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2956
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2957<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2958 undefined behavior; this is a rare case, but can occur, for example, by doing
2959 a 32-bit division of -2147483648 by -1.</p>
2960
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame]2961<p>If the <tt>exact</tt> keyword is present, the result value of the
2962 <tt>sdiv</tt> is undefined if the result would be rounded or if overflow
2963 would occur.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2964
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2965<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2966<pre>
2967 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2968</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2969
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2970</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2971
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2972<!-- _______________________________________________________________________ -->
2973<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2974Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2975
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2976<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2977
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2978<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2979<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2980 &lt;result&gt; = fdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2981</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2982
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2983<h5>Overview:</h5>
2984<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2985
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2986<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2987<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2988 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2989 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2990
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2991<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2992<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2993
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2994<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2995<pre>
2996 &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]2997</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2998
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2999</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3000
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3001<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3002<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3003</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3004
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3005<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3006
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3007<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3008<pre>
3009 &lt;result&gt; = urem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3010</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3011
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3012<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3013<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3014 division of its two arguments.</p>
3015
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3016<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3017<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3018 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3019 values. Both arguments must have identical types.</p>
3020
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3021<h5>Semantics:</h5>
3022<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3023 This instruction always performs an unsigned division to get the
3024 remainder.</p>
3025
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3026<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3027 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3028
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3029<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3030
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3031<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3032<pre>
3033 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3034</pre>
3035
3036</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3037
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3038<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3039<div class="doc_subsubsection">
3040 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
3041</div>
3042
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3043<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3044
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3045<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3046<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3047 &lt;result&gt; = srem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3048</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3049
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3050<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3051<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3052 division of its two operands. This instruction can also take
3053 <a href="#t_vector">vector</a> versions of the values in which case the
3054 elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]3055
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3056<h5>Arguments:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3057<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3058 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3059 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3060
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3061<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3062<p>This instruction returns the <i>remainder</i> of a division (where the result
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3063 has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
3064 operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
3065 a value. For more information about the difference,
3066 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3067 Math Forum</a>. For a table of how this is implemented in various languages,
3068 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3069 Wikipedia: modulo operation</a>.</p>
3070
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3071<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3072 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3073
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3074<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3075 Overflow also leads to undefined behavior; this is a rare case, but can
3076 occur, for example, by taking the remainder of a 32-bit division of
3077 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3078 lets srem be implemented using instructions that return both the result of
3079 the division and the remainder.)</p>
3080
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3081<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3082<pre>
3083 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3084</pre>
3085
3086</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3087
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3088<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3089<div class="doc_subsubsection">
3090 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
3091
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3092<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3093
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3094<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3095<pre>
3096 &lt;result&gt; = frem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3097</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3098
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3099<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3100<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3101 its two operands.</p>
3102
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3103<h5>Arguments:</h5>
3104<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3105 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3106 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3107
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3108<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3109<p>This instruction returns the <i>remainder</i> of a division. The remainder
3110 has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3111
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3112<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3113<pre>
3114 &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]3115</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3116
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3117</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]3118
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3119<!-- ======================================================================= -->
3120<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
3121Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3122
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3123<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3124
3125<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3126 program. They are generally very efficient instructions and can commonly be
3127 strength reduced from other instructions. They require two operands of the
3128 same type, execute an operation on them, and produce a single value. The
3129 resulting value is the same type as its operands.</p>
3130
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3131</div>
3132
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3133<!-- _______________________________________________________________________ -->
3134<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
3135Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3136
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3137<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3138
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3139<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3140<pre>
3141 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3142</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3143
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3144<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3145<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3146 a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3147
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3148<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3149<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3150 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3151 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3152
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3153<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3154<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3155 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3156 is (statically or dynamically) negative or equal to or larger than the number
3157 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3158 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3159 shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3160
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3161<h5>Example:</h5>
3162<pre>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3163 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3164 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3165 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3166 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3167 &lt;result&gt; = shl &lt;2 x i32&gt; &lt; i32 1, i32 1&gt;, &lt; i32 1, i32 2&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 2, i32 4&gt;</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3168</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3169
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3170</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3171
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3172<!-- _______________________________________________________________________ -->
3173<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
3174Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3175
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3176<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3177
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3178<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3179<pre>
3180 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3181</pre>
3182
3183<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3184<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3185 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3186
3187<h5>Arguments:</h5>
3188<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3189 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3190 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3191
3192<h5>Semantics:</h5>
3193<p>This instruction always performs a logical shift right operation. The most
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3194 significant bits of the result will be filled with zero bits after the shift.
3195 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3196 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3197 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3198 shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3199
3200<h5>Example:</h5>
3201<pre>
3202 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3203 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3204 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3205 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3206 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3207 &lt;result&gt; = lshr &lt;2 x i32&gt; &lt; i32 -2, i32 4&gt;, &lt; i32 1, i32 2&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0x7FFFFFFF, i32 1&gt;</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3208</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3209
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3210</div>
3211
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3212<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3213<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
3214Instruction</a> </div>
3215<div class="doc_text">
3216
3217<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3218<pre>
3219 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3220</pre>
3221
3222<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3223<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3224 operand shifted to the right a specified number of bits with sign
3225 extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3226
3227<h5>Arguments:</h5>
3228<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3229 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3230 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3231
3232<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3233<p>This instruction always performs an arithmetic shift right operation, The
3234 most significant bits of the result will be filled with the sign bit
3235 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3236 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3237 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3238 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3239
3240<h5>Example:</h5>
3241<pre>
3242 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3243 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3244 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3245 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3246 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3247 &lt;result&gt; = ashr &lt;2 x i32&gt; &lt; i32 -2, i32 4&gt;, &lt; i32 1, i32 3&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 -1, i32 0&gt;</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3248</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3249
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3250</div>
3251
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3252<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3253<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
3254Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3255
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3256<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3257
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3258<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3259<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3260 &lt;result&gt; = and &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3261</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3262
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3263<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3264<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3265 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3266
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3267<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3268<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3269 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3270 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3271
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3272<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3273<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3274
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3275<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3276 <tbody>
3277 <tr>
3278 <td>In0</td>
3279 <td>In1</td>
3280 <td>Out</td>
3281 </tr>
3282 <tr>
3283 <td>0</td>
3284 <td>0</td>
3285 <td>0</td>
3286 </tr>
3287 <tr>
3288 <td>0</td>
3289 <td>1</td>
3290 <td>0</td>
3291 </tr>
3292 <tr>
3293 <td>1</td>
3294 <td>0</td>
3295 <td>0</td>
3296 </tr>
3297 <tr>
3298 <td>1</td>
3299 <td>1</td>
3300 <td>1</td>
3301 </tr>
3302 </tbody>
3303</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3304
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3305<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3306<pre>
3307 &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3308 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3309 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3310</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3311</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3312<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3313<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3314
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3315<div class="doc_text">
3316
3317<h5>Syntax:</h5>
3318<pre>
3319 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3320</pre>
3321
3322<h5>Overview:</h5>
3323<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
3324 two operands.</p>
3325
3326<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3327<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3328 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3329 values. Both arguments must have identical types.</p>
3330
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3331<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3332<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3333
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3334<table border="1" cellspacing="0" cellpadding="4">
3335 <tbody>
3336 <tr>
3337 <td>In0</td>
3338 <td>In1</td>
3339 <td>Out</td>
3340 </tr>
3341 <tr>
3342 <td>0</td>
3343 <td>0</td>
3344 <td>0</td>
3345 </tr>
3346 <tr>
3347 <td>0</td>
3348 <td>1</td>
3349 <td>1</td>
3350 </tr>
3351 <tr>
3352 <td>1</td>
3353 <td>0</td>
3354 <td>1</td>
3355 </tr>
3356 <tr>
3357 <td>1</td>
3358 <td>1</td>
3359 <td>1</td>
3360 </tr>
3361 </tbody>
3362</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3363
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3364<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3365<pre>
3366 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3367 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
3368 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3369</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3370
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3371</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3372
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3373<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3374<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
3375Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3376
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3377<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3378
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3379<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3380<pre>
3381 &lt;result&gt; = xor &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3382</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3383
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3384<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3385<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
3386 its two operands. The <tt>xor</tt> is used to implement the "one's
3387 complement" operation, which is the "~" operator in C.</p>
3388
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3389<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3390<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3391 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3392 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3393
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3394<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3395<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3396
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3397<table border="1" cellspacing="0" cellpadding="4">
3398 <tbody>
3399 <tr>
3400 <td>In0</td>
3401 <td>In1</td>
3402 <td>Out</td>
3403 </tr>
3404 <tr>
3405 <td>0</td>
3406 <td>0</td>
3407 <td>0</td>
3408 </tr>
3409 <tr>
3410 <td>0</td>
3411 <td>1</td>
3412 <td>1</td>
3413 </tr>
3414 <tr>
3415 <td>1</td>
3416 <td>0</td>
3417 <td>1</td>
3418 </tr>
3419 <tr>
3420 <td>1</td>
3421 <td>1</td>
3422 <td>0</td>
3423 </tr>
3424 </tbody>
3425</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3426
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3427<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3428<pre>
3429 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3430 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
3431 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
3432 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3433</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3434
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3435</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3436
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3437<!-- ======================================================================= -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3438<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3439 <a name="vectorops">Vector Operations</a>
3440</div>
3441
3442<div class="doc_text">
3443
3444<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3445 target-independent manner. These instructions cover the element-access and
3446 vector-specific operations needed to process vectors effectively. While LLVM
3447 does directly support these vector operations, many sophisticated algorithms
3448 will want to use target-specific intrinsics to take full advantage of a
3449 specific target.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3450
3451</div>
3452
3453<!-- _______________________________________________________________________ -->
3454<div class="doc_subsubsection">
3455 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
3456</div>
3457
3458<div class="doc_text">
3459
3460<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3461<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3462 &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]3463</pre>
3464
3465<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3466<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
3467 from a vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3468
3469
3470<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3471<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
3472 of <a href="#t_vector">vector</a> type. The second operand is an index
3473 indicating the position from which to extract the element. The index may be
3474 a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3475
3476<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3477<p>The result is a scalar of the same type as the element type of
3478 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
3479 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3480 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3481
3482<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3483<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3484 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3485</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3486
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3487</div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3488
3489<!-- _______________________________________________________________________ -->
3490<div class="doc_subsubsection">
3491 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
3492</div>
3493
3494<div class="doc_text">
3495
3496<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3497<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]3498 &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]3499</pre>
3500
3501<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3502<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
3503 vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3504
3505<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3506<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
3507 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
3508 whose type must equal the element type of the first operand. The third
3509 operand is an index indicating the position at which to insert the value.
3510 The index may be a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3511
3512<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3513<p>The result is a vector of the same type as <tt>val</tt>. Its element values
3514 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
3515 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3516 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3517
3518<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3519<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3520 %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]3521</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3522
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3523</div>
3524
3525<!-- _______________________________________________________________________ -->
3526<div class="doc_subsubsection">
3527 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3528</div>
3529
3530<div class="doc_text">
3531
3532<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3533<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3534 &lt;result&gt; = shufflevector &lt;n x &lt;ty&gt;&gt; &lt;v1&gt;, &lt;n x &lt;ty&gt;&gt; &lt;v2&gt;, &lt;m x i32&gt; &lt;mask&gt; <i>; yields &lt;m x &lt;ty&gt;&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3535</pre>
3536
3537<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3538<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
3539 from two input vectors, returning a vector with the same element type as the
3540 input and length that is the same as the shuffle mask.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3541
3542<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3543<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
3544 with types that match each other. The third argument is a shuffle mask whose
3545 element type is always 'i32'. The result of the instruction is a vector
3546 whose length is the same as the shuffle mask and whose element type is the
3547 same as the element type of the first two operands.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3548
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3549<p>The shuffle mask operand is required to be a constant vector with either
3550 constant integer or undef values.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3551
3552<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3553<p>The elements of the two input vectors are numbered from left to right across
3554 both of the vectors. The shuffle mask operand specifies, for each element of
3555 the result vector, which element of the two input vectors the result element
3556 gets. The element selector may be undef (meaning "don't care") and the
3557 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3558
3559<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3560<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3561 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3562 &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]3563 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
3564 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i> - Identity shuffle.
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3565 %result = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
3566 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
3567 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
3568 &lt;8 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7 &gt; <i>; yields &lt;8 x i32&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3569</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3570
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3571</div>
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]3572
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3573<!-- ======================================================================= -->
3574<div class="doc_subsection">
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3575 <a name="aggregateops">Aggregate Operations</a>
3576</div>
3577
3578<div class="doc_text">
3579
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3580<p>LLVM supports several instructions for working with aggregate values.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3581
3582</div>
3583
3584<!-- _______________________________________________________________________ -->
3585<div class="doc_subsubsection">
3586 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3587</div>
3588
3589<div class="doc_text">
3590
3591<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3592<pre>
3593 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3594</pre>
3595
3596<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3597<p>The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3598 or array element from an aggregate value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3599
3600<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3601<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
3602 of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type. The
3603 operands are constant indices to specify which value to extract in a similar
3604 manner as indices in a
3605 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3606
3607<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3608<p>The result is the value at the position in the aggregate specified by the
3609 index operands.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3610
3611<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3612<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3613 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3614</pre>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3615
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3616</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3617
3618<!-- _______________________________________________________________________ -->
3619<div class="doc_subsubsection">
3620 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3621</div>
3622
3623<div class="doc_text">
3624
3625<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3626<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3627 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;val&gt;, &lt;idx&gt; <i>; yields &lt;n x &lt;ty&gt;&gt;</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3628</pre>
3629
3630<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3631<p>The '<tt>insertvalue</tt>' instruction inserts a value into a struct field or
3632 array element in an aggregate.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3633
3634
3635<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3636<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
3637 of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type. The
3638 second operand is a first-class value to insert. The following operands are
3639 constant indices indicating the position at which to insert the value in a
3640 similar manner as indices in a
3641 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction. The
3642 value to insert must have the same type as the value identified by the
3643 indices.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3644
3645<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3646<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
3647 that of <tt>val</tt> except that the value at the position specified by the
3648 indices is that of <tt>elt</tt>.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3649
3650<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3651<pre>
Dan Gohman52bb2db2008-06-23 15:26:37 +0000[diff] [blame]3652 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3653</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3654
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3655</div>
3656
3657
3658<!-- ======================================================================= -->
3659<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3660 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3661</div>
3662
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3663<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3664
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3665<p>A key design point of an SSA-based representation is how it represents
3666 memory. In LLVM, no memory locations are in SSA form, which makes things
3667 very simple. This section describes how to read, write, allocate, and free
3668 memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3669
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3670</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3671
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3672<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3673<div class="doc_subsubsection">
3674 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3675</div>
3676
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3677<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3678
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3679<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3680<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3681 &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]3682</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3683
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3684<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3685<p>The '<tt>malloc</tt>' instruction allocates memory from the system heap and
3686 returns a pointer to it. The object is always allocated in the generic
3687 address space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3688
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3689<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3690<p>The '<tt>malloc</tt>' instruction allocates
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3691 <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory from the operating
3692 system and returns a pointer of the appropriate type to the program. If
3693 "NumElements" is specified, it is the number of elements allocated, otherwise
3694 "NumElements" is defaulted to be one. If a constant alignment is specified,
3695 the value result of the allocation is guaranteed to be aligned to at least
3696 that boundary. If not specified, or if zero, the target can choose to align
3697 the allocation on any convenient boundary compatible with the type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3698
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3699<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3700
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3701<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3702<p>Memory is allocated using the system "<tt>malloc</tt>" function, and a
3703 pointer is returned. The result of a zero byte allocation is undefined. The
3704 result is null if there is insufficient memory available.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3705
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3706<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3707<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3708 %array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3709
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3710 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3711 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3712 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3713 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3714 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3715</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]3716
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3717<p>Note that the code generator does not yet respect the alignment value.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]3718
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3719</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3720
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3721<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3722<div class="doc_subsubsection">
3723 <a name="i_free">'<tt>free</tt>' Instruction</a>
3724</div>
3725
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3726<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3727
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3728<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3729<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3730 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3731</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3732
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3733<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3734<p>The '<tt>free</tt>' instruction returns memory back to the unused memory heap
3735 to be reallocated in the future.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3736
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3737<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3738<p>'<tt>value</tt>' shall be a pointer value that points to a value that was
3739 allocated with the '<tt><a href="#i_malloc">malloc</a></tt>' instruction.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3740
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3741<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3742<p>Access to the memory pointed to by the pointer is no longer defined after
3743 this instruction executes. If the pointer is null, the operation is a
3744 noop.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3745
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3746<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3747<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3748 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3749 free [4 x i8]* %array
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3750</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3751
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3752</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3753
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3754<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3755<div class="doc_subsubsection">
3756 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3757</div>
3758
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3759<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3760
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3761<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3762<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3763 &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]3764</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3765
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3766<h5>Overview:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3767<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3768 currently executing function, to be automatically released when this function
3769 returns to its caller. The object is always allocated in the generic address
3770 space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3771
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3772<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3773<p>The '<tt>alloca</tt>' instruction
3774 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
3775 runtime stack, returning a pointer of the appropriate type to the program.
3776 If "NumElements" is specified, it is the number of elements allocated,
3777 otherwise "NumElements" is defaulted to be one. If a constant alignment is
3778 specified, the value result of the allocation is guaranteed to be aligned to
3779 at least that boundary. If not specified, or if zero, the target can choose
3780 to align the allocation on any convenient boundary compatible with the
3781 type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3782
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3783<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3784
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3785<h5>Semantics:</h5>
Bill Wendling871eb0a2009-05-08 20:49:29 +0000[diff] [blame]3786<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3787 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
3788 memory is automatically released when the function returns. The
3789 '<tt>alloca</tt>' instruction is commonly used to represent automatic
3790 variables that must have an address available. When the function returns
3791 (either with the <tt><a href="#i_ret">ret</a></tt>
3792 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
3793 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3794
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3795<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3796<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3797 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
3798 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3799 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
3800 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3801</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3802
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3803</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3804
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3805<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3806<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3807Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3808
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3809<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3810
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3811<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3812<pre>
3813 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]
3814 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]
3815</pre>
3816
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3817<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3818<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3819
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3820<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3821<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
3822 from which to load. The pointer must point to
3823 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
3824 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
3825 number or order of execution of this <tt>load</tt> with other
3826 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3827 instructions. </p>
3828
3829<p>The optional constant "align" argument specifies the alignment of the
3830 operation (that is, the alignment of the memory address). A value of 0 or an
3831 omitted "align" argument means that the operation has the preferential
3832 alignment for the target. It is the responsibility of the code emitter to
3833 ensure that the alignment information is correct. Overestimating the
3834 alignment results in an undefined behavior. Underestimating the alignment may
3835 produce less efficient code. An alignment of 1 is always safe.</p>
3836
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3837<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3838<p>The location of memory pointed to is loaded. If the value being loaded is of
3839 scalar type then the number of bytes read does not exceed the minimum number
3840 of bytes needed to hold all bits of the type. For example, loading an
3841 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
3842 <tt>i20</tt> with a size that is not an integral number of bytes, the result
3843 is undefined if the value was not originally written using a store of the
3844 same type.</p>
3845
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3846<h5>Examples:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3847<pre>
3848 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
3849 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3850 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3851</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3852
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3853</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3854
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3855<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3856<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3857Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3858
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]3859<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3860
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3861<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3862<pre>
3863 store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]3864 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]3865</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3866
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3867<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3868<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3869
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3870<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3871<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
3872 and an address at which to store it. The type of the
3873 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
3874 the <a href="#t_firstclass">first class</a> type of the
3875 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked
3876 as <tt>volatile</tt>, then the optimizer is not allowed to modify the number
3877 or order of execution of this <tt>store</tt> with other
3878 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3879 instructions.</p>
3880
3881<p>The optional constant "align" argument specifies the alignment of the
3882 operation (that is, the alignment of the memory address). A value of 0 or an
3883 omitted "align" argument means that the operation has the preferential
3884 alignment for the target. It is the responsibility of the code emitter to
3885 ensure that the alignment information is correct. Overestimating the
3886 alignment results in an undefined behavior. Underestimating the alignment may
3887 produce less efficient code. An alignment of 1 is always safe.</p>
3888
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3889<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3890<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
3891 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
3892 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
3893 does not exceed the minimum number of bytes needed to hold all bits of the
3894 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
3895 writing a value of a type like <tt>i20</tt> with a size that is not an
3896 integral number of bytes, it is unspecified what happens to the extra bits
3897 that do not belong to the type, but they will typically be overwritten.</p>
3898
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3899<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3900<pre>
3901 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]3902 store i32 3, i32* %ptr <i>; yields {void}</i>
3903 %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]3904</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3905
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3906</div>
3907
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3908<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3909<div class="doc_subsubsection">
3910 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3911</div>
3912
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3913<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3914
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3915<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3916<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3917 &lt;result&gt; = getelementptr &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]3918 &lt;result&gt; = getelementptr inbounds &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3919</pre>
3920
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3921<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3922<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
3923 subelement of an aggregate data structure. It performs address calculation
3924 only and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3925
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3926<h5>Arguments:</h5>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3927<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]3928 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3929 elements of the aggregate object are indexed. The interpretation of each
3930 index is dependent on the type being indexed into. The first index always
3931 indexes the pointer value given as the first argument, the second index
3932 indexes a value of the type pointed to (not necessarily the value directly
3933 pointed to, since the first index can be non-zero), etc. The first type
3934 indexed into must be a pointer value, subsequent types can be arrays, vectors
3935 and structs. Note that subsequent types being indexed into can never be
3936 pointers, since that would require loading the pointer before continuing
3937 calculation.</p>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3938
3939<p>The type of each index argument depends on the type it is indexing into.
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]3940 When indexing into a (optionally packed) structure, only <tt>i32</tt> integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3941 <b>constants</b> are allowed. When indexing into an array, pointer or
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]3942 vector, integers of any width are allowed, and they are not required to be
3943 constant.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3944
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3945<p>For example, let's consider a C code fragment and how it gets compiled to
3946 LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3947
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3948<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3949<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3950struct RT {
3951 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3952 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3953 char C;
3954};
3955struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3956 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3957 double Y;
3958 struct RT Z;
3959};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3960
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3961int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3962 return &amp;s[1].Z.B[5][13];
3963}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3964</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3965</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3966
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3967<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3968
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3969<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3970<pre>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]3971%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
3972%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3973
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]3974define i32* @foo(%ST* %s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3975entry:
3976 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3977 ret i32* %reg
3978}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3979</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3980</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3981
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3982<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3983<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3984 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
3985 }</tt>' type, a structure. The second index indexes into the third element
3986 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3987 i8 }</tt>' type, another structure. The third index indexes into the second
3988 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
3989 array. The two dimensions of the array are subscripted into, yielding an
3990 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
3991 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3992
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3993<p>Note that it is perfectly legal to index partially through a structure,
3994 returning a pointer to an inner element. Because of this, the LLVM code for
3995 the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3996
3997<pre>
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]3998 define i32* @foo(%ST* %s) {
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3999 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4000 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4001 %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]4002 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4003 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4004 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4005 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4006</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]4007
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4008<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman0a28d182009-07-29 16:00:30 +0000[diff] [blame]4009 <tt>getelementptr</tt> is undefined if the base pointer is not an
4010 <i>in bounds</i> address of an allocated object, or if any of the addresses
Dan Gohmanb255b882009-08-20 17:08:17 +0000[diff] [blame]4011 that would be formed by successive addition of the offsets implied by the
4012 indices to the base address with infinitely precise arithmetic are not an
4013 <i>in bounds</i> address of that allocated object.
Dan Gohman0a28d182009-07-29 16:00:30 +0000[diff] [blame]4014 The <i>in bounds</i> addresses for an allocated object are all the addresses
Dan Gohmanb255b882009-08-20 17:08:17 +0000[diff] [blame]4015 that point into the object, plus the address one byte past the end.</p>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4016
4017<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4018 the base address with silently-wrapping two's complement arithmetic, and
4019 the result value of the <tt>getelementptr</tt> may be outside the object
4020 pointed to by the base pointer. The result value may not necessarily be
4021 used to access memory though, even if it happens to point into allocated
4022 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4023 section for more information.</p>
4024
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4025<p>The getelementptr instruction is often confusing. For some more insight into
4026 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4027
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4028<h5>Example:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4029<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4030 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4031 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4032 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4033 %vptr = getelementptr {i32, &lt;2 x i8&gt;}* %svptr, i64 0, i32 1, i32 1
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4034 <i>; yields i8*:eptr</i>
4035 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta9f805c22009-04-25 07:27:44 +0000[diff] [blame]4036 <i>; yields i32*:iptr</i>
Sanjiv Gupta16ffa802009-04-24 16:38:13 +0000[diff] [blame]4037 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4038</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4039
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4040</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4041
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4042<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4043<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4044</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4045
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4046<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4047
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4048<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4049 which all take a single operand and a type. They perform various bit
4050 conversions on the operand.</p>
4051
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4052</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4053
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4054<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4055<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4056 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
4057</div>
4058<div class="doc_text">
4059
4060<h5>Syntax:</h5>
4061<pre>
4062 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4063</pre>
4064
4065<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4066<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4067 type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4068
4069<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4070<p>The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
4071 be an <a href="#t_integer">integer</a> type, and a type that specifies the
4072 size and type of the result, which must be
4073 an <a href="#t_integer">integer</a> type. The bit size of <tt>value</tt> must
4074 be larger than the bit size of <tt>ty2</tt>. Equal sized types are not
4075 allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4076
4077<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4078<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4079 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4080 source size must be larger than the destination size, <tt>trunc</tt> cannot
4081 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4082
4083<h5>Example:</h5>
4084<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4085 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4086 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
4087 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4088</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4089
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4090</div>
4091
4092<!-- _______________________________________________________________________ -->
4093<div class="doc_subsubsection">
4094 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
4095</div>
4096<div class="doc_text">
4097
4098<h5>Syntax:</h5>
4099<pre>
4100 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4101</pre>
4102
4103<h5>Overview:</h5>
4104<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4105 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4106
4107
4108<h5>Arguments:</h5>
4109<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4110 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4111 also be of <a href="#t_integer">integer</a> type. The bit size of the
4112 <tt>value</tt> must be smaller than the bit size of the destination type,
4113 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4114
4115<h5>Semantics:</h5>
4116<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4117 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4118
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]4119<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]4120
4121<h5>Example:</h5>
4122<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4123 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4124 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4125</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4126
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4127</div>
4128
4129<!-- _______________________________________________________________________ -->
4130<div class="doc_subsubsection">
4131 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
4132</div>
4133<div class="doc_text">
4134
4135<h5>Syntax:</h5>
4136<pre>
4137 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4138</pre>
4139
4140<h5>Overview:</h5>
4141<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4142
4143<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4144<p>The '<tt>sext</tt>' instruction takes a value to cast, which must be of
4145 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4146 also be of <a href="#t_integer">integer</a> type. The bit size of the
4147 <tt>value</tt> must be smaller than the bit size of the destination type,
4148 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4149
4150<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4151<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4152 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4153 of the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4154
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4155<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]4156
4157<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4158<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4159 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4160 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4161</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4162
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4163</div>
4164
4165<!-- _______________________________________________________________________ -->
4166<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4167 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
4168</div>
4169
4170<div class="doc_text">
4171
4172<h5>Syntax:</h5>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4173<pre>
4174 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4175</pre>
4176
4177<h5>Overview:</h5>
4178<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4179 <tt>ty2</tt>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4180
4181<h5>Arguments:</h5>
4182<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4183 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4184 to cast it to. The size of <tt>value</tt> must be larger than the size of
4185 <tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
4186 <i>no-op cast</i>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4187
4188<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4189<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
4190 <a href="#t_floating">floating point</a> type to a smaller
4191 <a href="#t_floating">floating point</a> type. If the value cannot fit
4192 within the destination type, <tt>ty2</tt>, then the results are
4193 undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4194
4195<h5>Example:</h5>
4196<pre>
4197 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4198 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4199</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4200
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4201</div>
4202
4203<!-- _______________________________________________________________________ -->
4204<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4205 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
4206</div>
4207<div class="doc_text">
4208
4209<h5>Syntax:</h5>
4210<pre>
4211 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4212</pre>
4213
4214<h5>Overview:</h5>
4215<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4216 floating point value.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4217
4218<h5>Arguments:</h5>
4219<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4220 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4221 a <a href="#t_floating">floating point</a> type to cast it to. The source
4222 type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4223
4224<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4225<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4226 <a href="#t_floating">floating point</a> type to a larger
4227 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4228 used to make a <i>no-op cast</i> because it always changes bits. Use
4229 <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]4230
4231<h5>Example:</h5>
4232<pre>
4233 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
4234 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
4235</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4236
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4237</div>
4238
4239<!-- _______________________________________________________________________ -->
4240<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]4241 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4242</div>
4243<div class="doc_text">
4244
4245<h5>Syntax:</h5>
4246<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4247 &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]4248</pre>
4249
4250<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4251<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4252 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4253
4254<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4255<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4256 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4257 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4258 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4259 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4260
4261<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4262<p>The '<tt>fptoui</tt>' instruction converts its
4263 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4264 towards zero) unsigned integer value. If the value cannot fit
4265 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4266
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4267<h5>Example:</h5>
4268<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4269 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4270 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4271 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4272</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4273
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4274</div>
4275
4276<!-- _______________________________________________________________________ -->
4277<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4278 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4279</div>
4280<div class="doc_text">
4281
4282<h5>Syntax:</h5>
4283<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4284 &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]4285</pre>
4286
4287<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4288<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4289 <a href="#t_floating">floating point</a> <tt>value</tt> to
4290 type <tt>ty2</tt>.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4291
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4292<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4293<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4294 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4295 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4296 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4297 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4298
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4299<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4300<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4301 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4302 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4303 the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4304
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]4305<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4306<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4307 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4308 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4309 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4310</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4311
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4312</div>
4313
4314<!-- _______________________________________________________________________ -->
4315<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4316 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4317</div>
4318<div class="doc_text">
4319
4320<h5>Syntax:</h5>
4321<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4322 &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]4323</pre>
4324
4325<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4326<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4327 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4328
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4329<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]4330<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4331 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4332 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4333 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4334 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4335
4336<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4337<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4338 integer quantity and converts it to the corresponding floating point
4339 value. If the value cannot fit in the floating point value, the results are
4340 undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4341
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4342<h5>Example:</h5>
4343<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4344 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4345 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4346</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4347
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4348</div>
4349
4350<!-- _______________________________________________________________________ -->
4351<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4352 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4353</div>
4354<div class="doc_text">
4355
4356<h5>Syntax:</h5>
4357<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4358 &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]4359</pre>
4360
4361<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4362<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
4363 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4364
4365<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]4366<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4367 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4368 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4369 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4370 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4371
4372<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4373<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
4374 quantity and converts it to the corresponding floating point value. If the
4375 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4376
4377<h5>Example:</h5>
4378<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4379 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4380 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4381</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4382
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4383</div>
4384
4385<!-- _______________________________________________________________________ -->
4386<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4387 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
4388</div>
4389<div class="doc_text">
4390
4391<h5>Syntax:</h5>
4392<pre>
4393 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4394</pre>
4395
4396<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4397<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
4398 the integer type <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4399
4400<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4401<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
4402 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
4403 <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4404
4405<h5>Semantics:</h5>
4406<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4407 <tt>ty2</tt> by interpreting the pointer value as an integer and either
4408 truncating or zero extending that value to the size of the integer type. If
4409 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
4410 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
4411 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
4412 change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4413
4414<h5>Example:</h5>
4415<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4416 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
4417 %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]4418</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4419
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4420</div>
4421
4422<!-- _______________________________________________________________________ -->
4423<div class="doc_subsubsection">
4424 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
4425</div>
4426<div class="doc_text">
4427
4428<h5>Syntax:</h5>
4429<pre>
4430 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4431</pre>
4432
4433<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4434<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
4435 pointer type, <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4436
4437<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4438<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4439 value to cast, and a type to cast it to, which must be a
4440 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4441
4442<h5>Semantics:</h5>
4443<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4444 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
4445 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
4446 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
4447 than the size of a pointer then a zero extension is done. If they are the
4448 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4449
4450<h5>Example:</h5>
4451<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4452 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
4453 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
4454 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4455</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4456
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4457</div>
4458
4459<!-- _______________________________________________________________________ -->
4460<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4461 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4462</div>
4463<div class="doc_text">
4464
4465<h5>Syntax:</h5>
4466<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4467 &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]4468</pre>
4469
4470<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4471<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4472 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4473
4474<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4475<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
4476 non-aggregate first class value, and a type to cast it to, which must also be
4477 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
4478 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
4479 identical. If the source type is a pointer, the destination type must also be
4480 a pointer. This instruction supports bitwise conversion of vectors to
4481 integers and to vectors of other types (as long as they have the same
4482 size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4483
4484<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4485<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4486 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
4487 this conversion. The conversion is done as if the <tt>value</tt> had been
4488 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
4489 be converted to other pointer types with this instruction. To convert
4490 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
4491 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4492
4493<h5>Example:</h5>
4494<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4495 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4496 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4497 %Z = bitcast &lt;2 x int&gt; %V to i64; <i>; yields i64: %V</i>
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]4498</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4499
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4500</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4501
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4502<!-- ======================================================================= -->
4503<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4504
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4505<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4506
4507<p>The instructions in this category are the "miscellaneous" instructions, which
4508 defy better classification.</p>
4509
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4510</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4511
4512<!-- _______________________________________________________________________ -->
4513<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4514</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4515
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4516<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4517
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4518<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4519<pre>
4520 &lt;result&gt; = icmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt;}:result</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4521</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4522
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4523<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4524<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
4525 boolean values based on comparison of its two integer, integer vector, or
4526 pointer operands.</p>
4527
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4528<h5>Arguments:</h5>
4529<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4530 the condition code indicating the kind of comparison to perform. It is not a
4531 value, just a keyword. The possible condition code are:</p>
4532
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4533<ol>
4534 <li><tt>eq</tt>: equal</li>
4535 <li><tt>ne</tt>: not equal </li>
4536 <li><tt>ugt</tt>: unsigned greater than</li>
4537 <li><tt>uge</tt>: unsigned greater or equal</li>
4538 <li><tt>ult</tt>: unsigned less than</li>
4539 <li><tt>ule</tt>: unsigned less or equal</li>
4540 <li><tt>sgt</tt>: signed greater than</li>
4541 <li><tt>sge</tt>: signed greater or equal</li>
4542 <li><tt>slt</tt>: signed less than</li>
4543 <li><tt>sle</tt>: signed less or equal</li>
4544</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4545
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]4546<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4547 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
4548 typed. They must also be identical types.</p>
4549
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4550<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4551<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
4552 condition code given as <tt>cond</tt>. The comparison performed always yields
4553 either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt>
4554 result, as follows:</p>
4555
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4556<ol>
4557 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4558 <tt>false</tt> otherwise. No sign interpretation is necessary or
4559 performed.</li>
4560
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4561 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4562 <tt>false</tt> otherwise. No sign interpretation is necessary or
4563 performed.</li>
4564
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4565 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4566 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4567
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4568 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4569 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4570 to <tt>op2</tt>.</li>
4571
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4572 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4573 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4574
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4575 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4576 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4577
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4578 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4579 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4580
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4581 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4582 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4583 to <tt>op2</tt>.</li>
4584
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4585 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4586 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4587
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4588 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4589 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4590</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4591
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4592<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4593 values are compared as if they were integers.</p>
4594
4595<p>If the operands are integer vectors, then they are compared element by
4596 element. The result is an <tt>i1</tt> vector with the same number of elements
4597 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4598
4599<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4600<pre>
4601 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4602 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4603 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4604 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4605 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4606 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4607</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4608
4609<p>Note that the code generator does not yet support vector types with
4610 the <tt>icmp</tt> instruction.</p>
4611
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4612</div>
4613
4614<!-- _______________________________________________________________________ -->
4615<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4616</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4617
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4618<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4619
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4620<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4621<pre>
4622 &lt;result&gt; = fcmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt;}:result</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4623</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4624
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4625<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4626<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
4627 values based on comparison of its operands.</p>
4628
4629<p>If the operands are floating point scalars, then the result type is a boolean
4630(<a href="#t_primitive"><tt>i1</tt></a>).</p>
4631
4632<p>If the operands are floating point vectors, then the result type is a vector
4633 of boolean with the same number of elements as the operands being
4634 compared.</p>
4635
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4636<h5>Arguments:</h5>
4637<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4638 the condition code indicating the kind of comparison to perform. It is not a
4639 value, just a keyword. The possible condition code are:</p>
4640
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4641<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4642 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4643 <li><tt>oeq</tt>: ordered and equal</li>
4644 <li><tt>ogt</tt>: ordered and greater than </li>
4645 <li><tt>oge</tt>: ordered and greater than or equal</li>
4646 <li><tt>olt</tt>: ordered and less than </li>
4647 <li><tt>ole</tt>: ordered and less than or equal</li>
4648 <li><tt>one</tt>: ordered and not equal</li>
4649 <li><tt>ord</tt>: ordered (no nans)</li>
4650 <li><tt>ueq</tt>: unordered or equal</li>
4651 <li><tt>ugt</tt>: unordered or greater than </li>
4652 <li><tt>uge</tt>: unordered or greater than or equal</li>
4653 <li><tt>ult</tt>: unordered or less than </li>
4654 <li><tt>ule</tt>: unordered or less than or equal</li>
4655 <li><tt>une</tt>: unordered or not equal</li>
4656 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4657 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4658</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4659
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4660<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4661 <i>unordered</i> means that either operand may be a QNAN.</p>
4662
4663<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
4664 a <a href="#t_floating">floating point</a> type or
4665 a <a href="#t_vector">vector</a> of floating point type. They must have
4666 identical types.</p>
4667
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4668<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4669<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4670 according to the condition code given as <tt>cond</tt>. If the operands are
4671 vectors, then the vectors are compared element by element. Each comparison
4672 performed always yields an <a href="#t_primitive">i1</a> result, as
4673 follows:</p>
4674
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4675<ol>
4676 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4677
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4678 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4679 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
4680
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4681 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4682 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
4683
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4684 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4685 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
4686
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4687 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4688 <tt>op1</tt> is less than <tt>op2</tt>.</li>
4689
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4690 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4691 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4692
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4693 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4694 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
4695
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4696 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4697
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4698 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4699 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
4700
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4701 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4702 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4703
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4704 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4705 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
4706
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4707 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4708 <tt>op1</tt> is less than <tt>op2</tt>.</li>
4709
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4710 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4711 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4712
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4713 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4714 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
4715
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4716 <li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4717
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4718 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4719</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4720
4721<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4722<pre>
4723 &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4724 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4725 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4726 &lt;result&gt; = fcmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4727</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4728
4729<p>Note that the code generator does not yet support vector types with
4730 the <tt>fcmp</tt> instruction.</p>
4731
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4732</div>
4733
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4734<!-- _______________________________________________________________________ -->
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4735<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4736 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4737</div>
4738
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4739<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4740
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4741<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4742<pre>
4743 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
4744</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4745
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4746<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4747<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
4748 SSA graph representing the function.</p>
4749
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4750<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4751<p>The type of the incoming values is specified with the first type field. After
4752 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
4753 one pair for each predecessor basic block of the current block. Only values
4754 of <a href="#t_firstclass">first class</a> type may be used as the value
4755 arguments to the PHI node. Only labels may be used as the label
4756 arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4757
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4758<p>There must be no non-phi instructions between the start of a basic block and
4759 the PHI instructions: i.e. PHI instructions must be first in a basic
4760 block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4761
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4762<p>For the purposes of the SSA form, the use of each incoming value is deemed to
4763 occur on the edge from the corresponding predecessor block to the current
4764 block (but after any definition of an '<tt>invoke</tt>' instruction's return
4765 value on the same edge).</p>
Jay Foadd2449092009-06-03 10:20:10 +0000[diff] [blame]4766
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4767<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4768<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4769 specified by the pair corresponding to the predecessor basic block that
4770 executed just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4771
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4772<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4773<pre>
4774Loop: ; Infinite loop that counts from 0 on up...
4775 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4776 %nextindvar = add i32 %indvar, 1
4777 br label %Loop
4778</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4779
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4780</div>
4781
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4782<!-- _______________________________________________________________________ -->
4783<div class="doc_subsubsection">
4784 <a name="i_select">'<tt>select</tt>' Instruction</a>
4785</div>
4786
4787<div class="doc_text">
4788
4789<h5>Syntax:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4790<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4791 &lt;result&gt; = select <i>selty</i> &lt;cond&gt;, &lt;ty&gt; &lt;val1&gt;, &lt;ty&gt; &lt;val2&gt; <i>; yields ty</i>
4792
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4793 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4794</pre>
4795
4796<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4797<p>The '<tt>select</tt>' instruction is used to choose one value based on a
4798 condition, without branching.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4799
4800
4801<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4802<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
4803 values indicating the condition, and two values of the
4804 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
4805 vectors and the condition is a scalar, then entire vectors are selected, not
4806 individual elements.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4807
4808<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4809<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
4810 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4811
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4812<p>If the condition is a vector of i1, then the value arguments must be vectors
4813 of the same size, and the selection is done element by element.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4814
4815<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4816<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4817 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4818</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4819
4820<p>Note that the code generator does not yet support conditions
4821 with vector type.</p>
4822
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4823</div>
4824
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]4825<!-- _______________________________________________________________________ -->
4826<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4827 <a name="i_call">'<tt>call</tt>' Instruction</a>
4828</div>
4829
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4830<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4831
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4832<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4833<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]4834 &lt;result&gt; = [tail] call [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] &lt;ty&gt; [&lt;fnty&gt;*] &lt;fnptrval&gt;(&lt;function args&gt;) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4835</pre>
4836
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4837<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4838<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4839
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4840<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4841<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4842
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4843<ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4844 <li>The optional "tail" marker indicates whether the callee function accesses
4845 any allocas or varargs in the caller. If the "tail" marker is present,
4846 the function call is eligible for tail call optimization. Note that calls
4847 may be marked "tail" even if they do not occur before
4848 a <a href="#i_ret"><tt>ret</tt></a> instruction.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4849
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4850 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
4851 convention</a> the call should use. If none is specified, the call
4852 defaults to using C calling conventions.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4853
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4854 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4855 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
4856 '<tt>inreg</tt>' attributes are valid here.</li>
4857
4858 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
4859 type of the return value. Functions that return no value are marked
4860 <tt><a href="#t_void">void</a></tt>.</li>
4861
4862 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
4863 being invoked. The argument types must match the types implied by this
4864 signature. This type can be omitted if the function is not varargs and if
4865 the function type does not return a pointer to a function.</li>
4866
4867 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4868 be invoked. In most cases, this is a direct function invocation, but
4869 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
4870 to function value.</li>
4871
4872 <li>'<tt>function args</tt>': argument list whose types match the function
4873 signature argument types. All arguments must be of
4874 <a href="#t_firstclass">first class</a> type. If the function signature
4875 indicates the function accepts a variable number of arguments, the extra
4876 arguments can be specified.</li>
4877
4878 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
4879 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
4880 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4881</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4882
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4883<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4884<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
4885 a specified function, with its incoming arguments bound to the specified
4886 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
4887 function, control flow continues with the instruction after the function
4888 call, and the return value of the function is bound to the result
4889 argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4890
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4891<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4892<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4893 %retval = call i32 @test(i32 %argc)
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]4894 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4895 %X = tail call i32 @foo() <i>; yields i32</i>
4896 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4897 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]4898
4899 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4900 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]4901 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
4902 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]4903 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]4904 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4905</pre>
4906
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4907</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4908
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4909<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4910<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]4911 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4912</div>
4913
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4914<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4915
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4916<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4917<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4918 &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]4919</pre>
4920
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4921<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4922<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4923 the "variable argument" area of a function call. It is used to implement the
4924 <tt>va_arg</tt> macro in C.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4925
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4926<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4927<p>This instruction takes a <tt>va_list*</tt> value and the type of the
4928 argument. It returns a value of the specified argument type and increments
4929 the <tt>va_list</tt> to point to the next argument. The actual type
4930 of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4931
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4932<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4933<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
4934 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
4935 to the next argument. For more information, see the variable argument
4936 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4937
4938<p>It is legal for this instruction to be called in a function which does not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4939 take a variable number of arguments, for example, the <tt>vfprintf</tt>
4940 function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4941
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4942<p><tt>va_arg</tt> is an LLVM instruction instead of
4943 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
4944 argument.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4945
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4946<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4947<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4948
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4949<p>Note that the code generator does not yet fully support va_arg on many
4950 targets. Also, it does not currently support va_arg with aggregate types on
4951 any target.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]4952
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4953</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4954
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4955<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4956<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4957<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4958
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4959<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4960
4961<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4962 well known names and semantics and are required to follow certain
4963 restrictions. Overall, these intrinsics represent an extension mechanism for
4964 the LLVM language that does not require changing all of the transformations
4965 in LLVM when adding to the language (or the bitcode reader/writer, the
4966 parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4967
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4968<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4969 prefix is reserved in LLVM for intrinsic names; thus, function names may not
4970 begin with this prefix. Intrinsic functions must always be external
4971 functions: you cannot define the body of intrinsic functions. Intrinsic
4972 functions may only be used in call or invoke instructions: it is illegal to
4973 take the address of an intrinsic function. Additionally, because intrinsic
4974 functions are part of the LLVM language, it is required if any are added that
4975 they be documented here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4976
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4977<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
4978 family of functions that perform the same operation but on different data
4979 types. Because LLVM can represent over 8 million different integer types,
4980 overloading is used commonly to allow an intrinsic function to operate on any
4981 integer type. One or more of the argument types or the result type can be
4982 overloaded to accept any integer type. Argument types may also be defined as
4983 exactly matching a previous argument's type or the result type. This allows
4984 an intrinsic function which accepts multiple arguments, but needs all of them
4985 to be of the same type, to only be overloaded with respect to a single
4986 argument or the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4987
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4988<p>Overloaded intrinsics will have the names of its overloaded argument types
4989 encoded into its function name, each preceded by a period. Only those types
4990 which are overloaded result in a name suffix. Arguments whose type is matched
4991 against another type do not. For example, the <tt>llvm.ctpop</tt> function
4992 can take an integer of any width and returns an integer of exactly the same
4993 integer width. This leads to a family of functions such as
4994 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
4995 %val)</tt>. Only one type, the return type, is overloaded, and only one type
4996 suffix is required. Because the argument's type is matched against the return
4997 type, it does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4998
4999<p>To learn how to add an intrinsic function, please see the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5000 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5001
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5002</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5003
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5004<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5005<div class="doc_subsection">
5006 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
5007</div>
5008
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5009<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5010
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5011<p>Variable argument support is defined in LLVM with
5012 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5013 intrinsic functions. These functions are related to the similarly named
5014 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5015
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5016<p>All of these functions operate on arguments that use a target-specific value
5017 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5018 not define what this type is, so all transformations should be prepared to
5019 handle these functions regardless of the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5020
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]5021<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5022 instruction and the variable argument handling intrinsic functions are
5023 used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5024
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5025<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5026<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5027define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5028 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5029 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5030 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5031 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5032
5033 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5034 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5035
5036 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5037 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5038 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5039 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5040 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5041
5042 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5043 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5044 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5045}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5046
5047declare void @llvm.va_start(i8*)
5048declare void @llvm.va_copy(i8*, i8*)
5049declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5050</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5051</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5052
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5053</div>
5054
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5055<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5056<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5057 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5058</div>
5059
5060
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5061<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5062
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5063<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5064<pre>
5065 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5066</pre>
5067
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5068<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5069<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5070 for subsequent use by <tt><a href="#i_va_arg">va_arg</a></tt>.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5071
5072<h5>Arguments:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5073<p>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5074
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5075<h5>Semantics:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5076<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5077 macro available in C. In a target-dependent way, it initializes
5078 the <tt>va_list</tt> element to which the argument points, so that the next
5079 call to <tt>va_arg</tt> will produce the first variable argument passed to
5080 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5081 need to know the last argument of the function as the compiler can figure
5082 that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5083
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5084</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5085
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5086<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5087<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5088 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5089</div>
5090
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5091<div class="doc_text">
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5092
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5093<h5>Syntax:</h5>
5094<pre>
5095 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5096</pre>
5097
5098<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5099<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5100 which has been initialized previously
5101 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5102 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5103
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5104<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5105<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]5106
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5107<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5108<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5109 macro available in C. In a target-dependent way, it destroys
5110 the <tt>va_list</tt> element to which the argument points. Calls
5111 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5112 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5113 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5114
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5115</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5116
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5117<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5118<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5119 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5120</div>
5121
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5122<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5123
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5124<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5125<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5126 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5127</pre>
5128
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5129<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5130<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5131 from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5132
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5133<h5>Arguments:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5134<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5135 The second argument is a pointer to a <tt>va_list</tt> element to copy
5136 from.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5137
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5138<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5139<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5140 macro available in C. In a target-dependent way, it copies the
5141 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5142 element. This intrinsic is necessary because
5143 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5144 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5145
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5146</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5147
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5148<!-- ======================================================================= -->
5149<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5150 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
5151</div>
5152
5153<div class="doc_text">
5154
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5155<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5156Collection</a> (GC) requires the implementation and generation of these
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5157intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5158roots on the stack</a>, as well as garbage collector implementations that
5159require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5160barriers. Front-ends for type-safe garbage collected languages should generate
5161these intrinsics to make use of the LLVM garbage collectors. For more details,
5162see <a href="GarbageCollection.html">Accurate Garbage Collection with
5163LLVM</a>.</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5164
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5165<p>The garbage collection intrinsics only operate on objects in the generic
5166 address space (address space zero).</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5167
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5168</div>
5169
5170<!-- _______________________________________________________________________ -->
5171<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5172 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5173</div>
5174
5175<div class="doc_text">
5176
5177<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5178<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5179 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5180</pre>
5181
5182<h5>Overview:</h5>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]5183<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5184 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5185
5186<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5187<p>The first argument specifies the address of a stack object that contains the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5188 root pointer. The second pointer (which must be either a constant or a
5189 global value address) contains the meta-data to be associated with the
5190 root.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5191
5192<h5>Semantics:</h5>
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]5193<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5194 location. At compile-time, the code generator generates information to allow
5195 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5196 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5197 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5198
5199</div>
5200
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5201<!-- _______________________________________________________________________ -->
5202<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5203 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5204</div>
5205
5206<div class="doc_text">
5207
5208<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5209<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5210 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5211</pre>
5212
5213<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5214<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5215 locations, allowing garbage collector implementations that require read
5216 barriers.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5217
5218<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5219<p>The second argument is the address to read from, which should be an address
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5220 allocated from the garbage collector. The first object is a pointer to the
5221 start of the referenced object, if needed by the language runtime (otherwise
5222 null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5223
5224<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5225<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5226 instruction, but may be replaced with substantially more complex code by the
5227 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5228 may only be used in a function which <a href="#gc">specifies a GC
5229 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5230
5231</div>
5232
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5233<!-- _______________________________________________________________________ -->
5234<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5235 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5236</div>
5237
5238<div class="doc_text">
5239
5240<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5241<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5242 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5243</pre>
5244
5245<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5246<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5247 locations, allowing garbage collector implementations that require write
5248 barriers (such as generational or reference counting collectors).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5249
5250<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5251<p>The first argument is the reference to store, the second is the start of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5252 object to store it to, and the third is the address of the field of Obj to
5253 store to. If the runtime does not require a pointer to the object, Obj may
5254 be null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5255
5256<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5257<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5258 instruction, but may be replaced with substantially more complex code by the
5259 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5260 may only be used in a function which <a href="#gc">specifies a GC
5261 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5262
5263</div>
5264
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5265<!-- ======================================================================= -->
5266<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5267 <a name="int_codegen">Code Generator Intrinsics</a>
5268</div>
5269
5270<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5271
5272<p>These intrinsics are provided by LLVM to expose special features that may
5273 only be implemented with code generator support.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5274
5275</div>
5276
5277<!-- _______________________________________________________________________ -->
5278<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5279 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5280</div>
5281
5282<div class="doc_text">
5283
5284<h5>Syntax:</h5>
5285<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5286 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5287</pre>
5288
5289<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5290<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5291 target-specific value indicating the return address of the current function
5292 or one of its callers.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5293
5294<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5295<p>The argument to this intrinsic indicates which function to return the address
5296 for. Zero indicates the calling function, one indicates its caller, etc.
5297 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5298
5299<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5300<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5301 indicating the return address of the specified call frame, or zero if it
5302 cannot be identified. The value returned by this intrinsic is likely to be
5303 incorrect or 0 for arguments other than zero, so it should only be used for
5304 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5305
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5306<p>Note that calling this intrinsic does not prevent function inlining or other
5307 aggressive transformations, so the value returned may not be that of the
5308 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5309
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5310</div>
5311
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5312<!-- _______________________________________________________________________ -->
5313<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5314 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5315</div>
5316
5317<div class="doc_text">
5318
5319<h5>Syntax:</h5>
5320<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5321 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5322</pre>
5323
5324<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5325<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5326 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5327
5328<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5329<p>The argument to this intrinsic indicates which function to return the frame
5330 pointer for. Zero indicates the calling function, one indicates its caller,
5331 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5332
5333<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5334<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
5335 indicating the frame address of the specified call frame, or zero if it
5336 cannot be identified. The value returned by this intrinsic is likely to be
5337 incorrect or 0 for arguments other than zero, so it should only be used for
5338 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5339
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5340<p>Note that calling this intrinsic does not prevent function inlining or other
5341 aggressive transformations, so the value returned may not be that of the
5342 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5343
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5344</div>
5345
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5346<!-- _______________________________________________________________________ -->
5347<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5348 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5349</div>
5350
5351<div class="doc_text">
5352
5353<h5>Syntax:</h5>
5354<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5355 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5356</pre>
5357
5358<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5359<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
5360 of the function stack, for use
5361 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
5362 useful for implementing language features like scoped automatic variable
5363 sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5364
5365<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5366<p>This intrinsic returns a opaque pointer value that can be passed
5367 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
5368 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
5369 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
5370 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
5371 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
5372 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5373
5374</div>
5375
5376<!-- _______________________________________________________________________ -->
5377<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5378 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5379</div>
5380
5381<div class="doc_text">
5382
5383<h5>Syntax:</h5>
5384<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5385 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5386</pre>
5387
5388<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5389<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5390 the function stack to the state it was in when the
5391 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
5392 executed. This is useful for implementing language features like scoped
5393 automatic variable sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5394
5395<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5396<p>See the description
5397 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5398
5399</div>
5400
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5401<!-- _______________________________________________________________________ -->
5402<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5403 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5404</div>
5405
5406<div class="doc_text">
5407
5408<h5>Syntax:</h5>
5409<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5410 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]5411</pre>
5412
5413<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5414<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
5415 insert a prefetch instruction if supported; otherwise, it is a noop.
5416 Prefetches have no effect on the behavior of the program but can change its
5417 performance characteristics.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5418
5419<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5420<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
5421 specifier determining if the fetch should be for a read (0) or write (1),
5422 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
5423 locality, to (3) - extremely local keep in cache. The <tt>rw</tt>
5424 and <tt>locality</tt> arguments must be constant integers.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5425
5426<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5427<p>This intrinsic does not modify the behavior of the program. In particular,
5428 prefetches cannot trap and do not produce a value. On targets that support
5429 this intrinsic, the prefetch can provide hints to the processor cache for
5430 better performance.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5431
5432</div>
5433
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5434<!-- _______________________________________________________________________ -->
5435<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5436 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5437</div>
5438
5439<div class="doc_text">
5440
5441<h5>Syntax:</h5>
5442<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5443 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5444</pre>
5445
5446<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5447<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
5448 Counter (PC) in a region of code to simulators and other tools. The method
5449 is target specific, but it is expected that the marker will use exported
5450 symbols to transmit the PC of the marker. The marker makes no guarantees
5451 that it will remain with any specific instruction after optimizations. It is
5452 possible that the presence of a marker will inhibit optimizations. The
5453 intended use is to be inserted after optimizations to allow correlations of
5454 simulation runs.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5455
5456<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5457<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5458
5459<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5460<p>This intrinsic does not modify the behavior of the program. Backends that do
5461 not support this intrinisic may ignore it.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5462
5463</div>
5464
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5465<!-- _______________________________________________________________________ -->
5466<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5467 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5468</div>
5469
5470<div class="doc_text">
5471
5472<h5>Syntax:</h5>
5473<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5474 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5475</pre>
5476
5477<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5478<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5479 counter register (or similar low latency, high accuracy clocks) on those
5480 targets that support it. On X86, it should map to RDTSC. On Alpha, it
5481 should map to RPCC. As the backing counters overflow quickly (on the order
5482 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5483
5484<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5485<p>When directly supported, reading the cycle counter should not modify any
5486 memory. Implementations are allowed to either return a application specific
5487 value or a system wide value. On backends without support, this is lowered
5488 to a constant 0.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5489
5490</div>
5491
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5492<!-- ======================================================================= -->
5493<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5494 <a name="int_libc">Standard C Library Intrinsics</a>
5495</div>
5496
5497<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5498
5499<p>LLVM provides intrinsics for a few important standard C library functions.
5500 These intrinsics allow source-language front-ends to pass information about
5501 the alignment of the pointer arguments to the code generator, providing
5502 opportunity for more efficient code generation.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5503
5504</div>
5505
5506<!-- _______________________________________________________________________ -->
5507<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5508 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5509</div>
5510
5511<div class="doc_text">
5512
5513<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5514<p>This is an overloaded intrinsic. You can use <tt>llvm.memcpy</tt> on any
5515 integer bit width. Not all targets support all bit widths however.</p>
5516
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5517<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5518 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5519 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5520 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5521 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5522 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5523 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5524 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5525 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5526</pre>
5527
5528<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5529<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5530 source location to the destination location.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5531
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5532<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5533 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5534
5535<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5536<p>The first argument is a pointer to the destination, the second is a pointer
5537 to the source. The third argument is an integer argument specifying the
5538 number of bytes to copy, and the fourth argument is the alignment of the
5539 source and destination locations.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5540
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5541<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5542 then the caller guarantees that both the source and destination pointers are
5543 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5544
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5545<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5546<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5547 source location to the destination location, which are not allowed to
5548 overlap. It copies "len" bytes of memory over. If the argument is known to
5549 be aligned to some boundary, this can be specified as the fourth argument,
5550 otherwise it should be set to 0 or 1.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5551
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5552</div>
5553
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5554<!-- _______________________________________________________________________ -->
5555<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5556 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5557</div>
5558
5559<div class="doc_text">
5560
5561<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5562<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5563 width. Not all targets support all bit widths however.</p>
5564
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5565<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5566 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5567 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5568 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5569 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5570 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5571 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5572 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5573 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5574</pre>
5575
5576<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5577<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
5578 source location to the destination location. It is similar to the
5579 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
5580 overlap.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5581
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5582<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5583 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5584
5585<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5586<p>The first argument is a pointer to the destination, the second is a pointer
5587 to the source. The third argument is an integer argument specifying the
5588 number of bytes to copy, and the fourth argument is the alignment of the
5589 source and destination locations.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5590
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5591<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5592 then the caller guarantees that the source and destination pointers are
5593 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5594
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5595<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5596<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
5597 source location to the destination location, which may overlap. It copies
5598 "len" bytes of memory over. If the argument is known to be aligned to some
5599 boundary, this can be specified as the fourth argument, otherwise it should
5600 be set to 0 or 1.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5601
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5602</div>
5603
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5604<!-- _______________________________________________________________________ -->
5605<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5606 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5607</div>
5608
5609<div class="doc_text">
5610
5611<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5612<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5613 width. Not all targets support all bit widths however.</p>
5614
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5615<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5616 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5617 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5618 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5619 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5620 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5621 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5622 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5623 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5624</pre>
5625
5626<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5627<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
5628 particular byte value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5629
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5630<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
5631 intrinsic does not return a value, and takes an extra alignment argument.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5632
5633<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5634<p>The first argument is a pointer to the destination to fill, the second is the
5635 byte value to fill it with, the third argument is an integer argument
5636 specifying the number of bytes to fill, and the fourth argument is the known
5637 alignment of destination location.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5638
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5639<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5640 then the caller guarantees that the destination pointer is aligned to that
5641 boundary.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5642
5643<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5644<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
5645 at the destination location. If the argument is known to be aligned to some
5646 boundary, this can be specified as the fourth argument, otherwise it should
5647 be set to 0 or 1.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5648
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5649</div>
5650
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5651<!-- _______________________________________________________________________ -->
5652<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5653 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5654</div>
5655
5656<div class="doc_text">
5657
5658<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5659<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
5660 floating point or vector of floating point type. Not all targets support all
5661 types however.</p>
5662
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5663<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5664 declare float @llvm.sqrt.f32(float %Val)
5665 declare double @llvm.sqrt.f64(double %Val)
5666 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5667 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5668 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5669</pre>
5670
5671<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5672<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
5673 returning the same value as the libm '<tt>sqrt</tt>' functions would.
5674 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
5675 behavior for negative numbers other than -0.0 (which allows for better
5676 optimization, because there is no need to worry about errno being
5677 set). <tt>llvm.sqrt(-0.0)</tt> is defined to return -0.0 like IEEE sqrt.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5678
5679<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5680<p>The argument and return value are floating point numbers of the same
5681 type.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5682
5683<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5684<p>This function returns the sqrt of the specified operand if it is a
5685 nonnegative floating point number.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5686
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5687</div>
5688
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5689<!-- _______________________________________________________________________ -->
5690<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5691 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5692</div>
5693
5694<div class="doc_text">
5695
5696<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5697<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
5698 floating point or vector of floating point type. Not all targets support all
5699 types however.</p>
5700
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5701<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5702 declare float @llvm.powi.f32(float %Val, i32 %power)
5703 declare double @llvm.powi.f64(double %Val, i32 %power)
5704 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5705 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5706 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5707</pre>
5708
5709<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5710<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5711 specified (positive or negative) power. The order of evaluation of
5712 multiplications is not defined. When a vector of floating point type is
5713 used, the second argument remains a scalar integer value.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5714
5715<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5716<p>The second argument is an integer power, and the first is a value to raise to
5717 that power.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5718
5719<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5720<p>This function returns the first value raised to the second power with an
5721 unspecified sequence of rounding operations.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5722
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5723</div>
5724
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5725<!-- _______________________________________________________________________ -->
5726<div class="doc_subsubsection">
5727 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5728</div>
5729
5730<div class="doc_text">
5731
5732<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5733<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5734 floating point or vector of floating point type. Not all targets support all
5735 types however.</p>
5736
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5737<pre>
5738 declare float @llvm.sin.f32(float %Val)
5739 declare double @llvm.sin.f64(double %Val)
5740 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5741 declare fp128 @llvm.sin.f128(fp128 %Val)
5742 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5743</pre>
5744
5745<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5746<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5747
5748<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5749<p>The argument and return value are floating point numbers of the same
5750 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5751
5752<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5753<p>This function returns the sine of the specified operand, returning the same
5754 values as the libm <tt>sin</tt> functions would, and handles error conditions
5755 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5756
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5757</div>
5758
5759<!-- _______________________________________________________________________ -->
5760<div class="doc_subsubsection">
5761 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5762</div>
5763
5764<div class="doc_text">
5765
5766<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5767<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5768 floating point or vector of floating point type. Not all targets support all
5769 types however.</p>
5770
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5771<pre>
5772 declare float @llvm.cos.f32(float %Val)
5773 declare double @llvm.cos.f64(double %Val)
5774 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5775 declare fp128 @llvm.cos.f128(fp128 %Val)
5776 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5777</pre>
5778
5779<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5780<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5781
5782<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5783<p>The argument and return value are floating point numbers of the same
5784 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5785
5786<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5787<p>This function returns the cosine of the specified operand, returning the same
5788 values as the libm <tt>cos</tt> functions would, and handles error conditions
5789 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5790
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5791</div>
5792
5793<!-- _______________________________________________________________________ -->
5794<div class="doc_subsubsection">
5795 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5796</div>
5797
5798<div class="doc_text">
5799
5800<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5801<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5802 floating point or vector of floating point type. Not all targets support all
5803 types however.</p>
5804
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5805<pre>
5806 declare float @llvm.pow.f32(float %Val, float %Power)
5807 declare double @llvm.pow.f64(double %Val, double %Power)
5808 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5809 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5810 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5811</pre>
5812
5813<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5814<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5815 specified (positive or negative) power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5816
5817<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5818<p>The second argument is a floating point power, and the first is a value to
5819 raise to that power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5820
5821<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5822<p>This function returns the first value raised to the second power, returning
5823 the same values as the libm <tt>pow</tt> functions would, and handles error
5824 conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5825
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5826</div>
5827
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5828<!-- ======================================================================= -->
5829<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5830 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5831</div>
5832
5833<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5834
5835<p>LLVM provides intrinsics for a few important bit manipulation operations.
5836 These allow efficient code generation for some algorithms.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5837
5838</div>
5839
5840<!-- _______________________________________________________________________ -->
5841<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5842 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5843</div>
5844
5845<div class="doc_text">
5846
5847<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5848<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5849 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
5850
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5851<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5852 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5853 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5854 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5855</pre>
5856
5857<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5858<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
5859 values with an even number of bytes (positive multiple of 16 bits). These
5860 are useful for performing operations on data that is not in the target's
5861 native byte order.</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5862
5863<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5864<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
5865 and low byte of the input i16 swapped. Similarly,
5866 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
5867 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
5868 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
5869 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
5870 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
5871 more, respectively).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5872
5873</div>
5874
5875<!-- _______________________________________________________________________ -->
5876<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5877 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5878</div>
5879
5880<div class="doc_text">
5881
5882<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5883<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5884 width. Not all targets support all bit widths however.</p>
5885
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5886<pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5887 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5888 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5889 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5890 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5891 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5892</pre>
5893
5894<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5895<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
5896 in a value.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5897
5898<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5899<p>The only argument is the value to be counted. The argument may be of any
5900 integer type. The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5901
5902<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5903<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5904
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5905</div>
5906
5907<!-- _______________________________________________________________________ -->
5908<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5909 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5910</div>
5911
5912<div class="doc_text">
5913
5914<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5915<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
5916 integer bit width. Not all targets support all bit widths however.</p>
5917
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5918<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5919 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5920 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5921 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5922 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5923 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5924</pre>
5925
5926<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5927<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5928 leading zeros in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5929
5930<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5931<p>The only argument is the value to be counted. The argument may be of any
5932 integer type. The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5933
5934<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5935<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
5936 zeros in a variable. If the src == 0 then the result is the size in bits of
5937 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5938
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5939</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5940
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5941<!-- _______________________________________________________________________ -->
5942<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5943 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5944</div>
5945
5946<div class="doc_text">
5947
5948<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5949<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
5950 integer bit width. Not all targets support all bit widths however.</p>
5951
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5952<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5953 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5954 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5955 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5956 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5957 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5958</pre>
5959
5960<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5961<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5962 trailing zeros.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5963
5964<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5965<p>The only argument is the value to be counted. The argument may be of any
5966 integer type. The return type must match the argument type.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5967
5968<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5969<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
5970 zeros in a variable. If the src == 0 then the result is the size in bits of
5971 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5972
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5973</div>
5974
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5975<!-- ======================================================================= -->
5976<div class="doc_subsection">
5977 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
5978</div>
5979
5980<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5981
5982<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5983
5984</div>
5985
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5986<!-- _______________________________________________________________________ -->
5987<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5988 <a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5989</div>
5990
5991<div class="doc_text">
5992
5993<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5994<p>This is an overloaded intrinsic. You can use <tt>llvm.sadd.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5995 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5996
5997<pre>
5998 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
5999 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6000 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
6001</pre>
6002
6003<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6004<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6005 a signed addition of the two arguments, and indicate whether an overflow
6006 occurred during the signed summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6007
6008<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6009<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6010 be of integer types of any bit width, but they must have the same bit
6011 width. The second element of the result structure must be of
6012 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6013 undergo signed addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6014
6015<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6016<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6017 a signed addition of the two variables. They return a structure &mdash; the
6018 first element of which is the signed summation, and the second element of
6019 which is a bit specifying if the signed summation resulted in an
6020 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6021
6022<h5>Examples:</h5>
6023<pre>
6024 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6025 %sum = extractvalue {i32, i1} %res, 0
6026 %obit = extractvalue {i32, i1} %res, 1
6027 br i1 %obit, label %overflow, label %normal
6028</pre>
6029
6030</div>
6031
6032<!-- _______________________________________________________________________ -->
6033<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6034 <a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6035</div>
6036
6037<div class="doc_text">
6038
6039<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6040<p>This is an overloaded intrinsic. You can use <tt>llvm.uadd.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6041 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6042
6043<pre>
6044 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6045 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6046 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6047</pre>
6048
6049<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6050<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6051 an unsigned addition of the two arguments, and indicate whether a carry
6052 occurred during the unsigned summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6053
6054<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6055<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6056 be of integer types of any bit width, but they must have the same bit
6057 width. The second element of the result structure must be of
6058 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6059 undergo unsigned addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6060
6061<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6062<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6063 an unsigned addition of the two arguments. They return a structure &mdash;
6064 the first element of which is the sum, and the second element of which is a
6065 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6066
6067<h5>Examples:</h5>
6068<pre>
6069 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6070 %sum = extractvalue {i32, i1} %res, 0
6071 %obit = extractvalue {i32, i1} %res, 1
6072 br i1 %obit, label %carry, label %normal
6073</pre>
6074
6075</div>
6076
6077<!-- _______________________________________________________________________ -->
6078<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6079 <a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6080</div>
6081
6082<div class="doc_text">
6083
6084<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6085<p>This is an overloaded intrinsic. You can use <tt>llvm.ssub.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6086 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6087
6088<pre>
6089 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6090 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6091 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6092</pre>
6093
6094<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6095<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6096 a signed subtraction of the two arguments, and indicate whether an overflow
6097 occurred during the signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6098
6099<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6100<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6101 be of integer types of any bit width, but they must have the same bit
6102 width. The second element of the result structure must be of
6103 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6104 undergo signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6105
6106<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6107<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6108 a signed subtraction of the two arguments. They return a structure &mdash;
6109 the first element of which is the subtraction, and the second element of
6110 which is a bit specifying if the signed subtraction resulted in an
6111 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6112
6113<h5>Examples:</h5>
6114<pre>
6115 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6116 %sum = extractvalue {i32, i1} %res, 0
6117 %obit = extractvalue {i32, i1} %res, 1
6118 br i1 %obit, label %overflow, label %normal
6119</pre>
6120
6121</div>
6122
6123<!-- _______________________________________________________________________ -->
6124<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6125 <a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6126</div>
6127
6128<div class="doc_text">
6129
6130<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6131<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6132 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6133
6134<pre>
6135 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6136 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6137 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6138</pre>
6139
6140<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6141<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6142 an unsigned subtraction of the two arguments, and indicate whether an
6143 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6144
6145<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6146<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6147 be of integer types of any bit width, but they must have the same bit
6148 width. The second element of the result structure must be of
6149 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6150 undergo unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6151
6152<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6153<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6154 an unsigned subtraction of the two arguments. They return a structure &mdash;
6155 the first element of which is the subtraction, and the second element of
6156 which is a bit specifying if the unsigned subtraction resulted in an
6157 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6158
6159<h5>Examples:</h5>
6160<pre>
6161 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6162 %sum = extractvalue {i32, i1} %res, 0
6163 %obit = extractvalue {i32, i1} %res, 1
6164 br i1 %obit, label %overflow, label %normal
6165</pre>
6166
6167</div>
6168
6169<!-- _______________________________________________________________________ -->
6170<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6171 <a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6172</div>
6173
6174<div class="doc_text">
6175
6176<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6177<p>This is an overloaded intrinsic. You can use <tt>llvm.smul.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6178 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6179
6180<pre>
6181 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6182 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6183 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6184</pre>
6185
6186<h5>Overview:</h5>
6187
6188<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6189 a signed multiplication of the two arguments, and indicate whether an
6190 overflow occurred during the signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6191
6192<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6193<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6194 be of integer types of any bit width, but they must have the same bit
6195 width. The second element of the result structure must be of
6196 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6197 undergo signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6198
6199<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6200<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6201 a signed multiplication of the two arguments. They return a structure &mdash;
6202 the first element of which is the multiplication, and the second element of
6203 which is a bit specifying if the signed multiplication resulted in an
6204 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6205
6206<h5>Examples:</h5>
6207<pre>
6208 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6209 %sum = extractvalue {i32, i1} %res, 0
6210 %obit = extractvalue {i32, i1} %res, 1
6211 br i1 %obit, label %overflow, label %normal
6212</pre>
6213
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]6214</div>
6215
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6216<!-- _______________________________________________________________________ -->
6217<div class="doc_subsubsection">
6218 <a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
6219</div>
6220
6221<div class="doc_text">
6222
6223<h5>Syntax:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6224<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6225 on any integer bit width.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6226
6227<pre>
6228 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6229 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6230 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6231</pre>
6232
6233<h5>Overview:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6234<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6235 a unsigned multiplication of the two arguments, and indicate whether an
6236 overflow occurred during the unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6237
6238<h5>Arguments:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6239<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6240 be of integer types of any bit width, but they must have the same bit
6241 width. The second element of the result structure must be of
6242 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6243 undergo unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6244
6245<h5>Semantics:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6246<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6247 an unsigned multiplication of the two arguments. They return a structure
6248 &mdash; the first element of which is the multiplication, and the second
6249 element of which is a bit specifying if the unsigned multiplication resulted
6250 in an overflow.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6251
6252<h5>Examples:</h5>
6253<pre>
6254 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6255 %sum = extractvalue {i32, i1} %res, 0
6256 %obit = extractvalue {i32, i1} %res, 1
6257 br i1 %obit, label %overflow, label %normal
6258</pre>
6259
6260</div>
6261
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6262<!-- ======================================================================= -->
6263<div class="doc_subsection">
6264 <a name="int_debugger">Debugger Intrinsics</a>
6265</div>
6266
6267<div class="doc_text">
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6268
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6269<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
6270 prefix), are described in
6271 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
6272 Level Debugging</a> document.</p>
6273
6274</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6275
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6276<!-- ======================================================================= -->
6277<div class="doc_subsection">
6278 <a name="int_eh">Exception Handling Intrinsics</a>
6279</div>
6280
6281<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6282
6283<p>The LLVM exception handling intrinsics (which all start with
6284 <tt>llvm.eh.</tt> prefix), are described in
6285 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
6286 Handling</a> document.</p>
6287
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6288</div>
6289
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6290<!-- ======================================================================= -->
6291<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6292 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6293</div>
6294
6295<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6296
6297<p>This intrinsic makes it possible to excise one parameter, marked with
6298 the <tt>nest</tt> attribute, from a function. The result is a callable
6299 function pointer lacking the nest parameter - the caller does not need to
6300 provide a value for it. Instead, the value to use is stored in advance in a
6301 "trampoline", a block of memory usually allocated on the stack, which also
6302 contains code to splice the nest value into the argument list. This is used
6303 to implement the GCC nested function address extension.</p>
6304
6305<p>For example, if the function is
6306 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
6307 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
6308 follows:</p>
6309
6310<div class="doc_code">
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6311<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6312 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
6313 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
6314 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
6315 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6316</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6317</div>
6318
6319<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
6320 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
6321
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6322</div>
6323
6324<!-- _______________________________________________________________________ -->
6325<div class="doc_subsubsection">
6326 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
6327</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6328
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6329<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6330
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6331<h5>Syntax:</h5>
6332<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6333 declare i8* @llvm.init.trampoline(i8* &lt;tramp&gt;, i8* &lt;func&gt;, i8* &lt;nval&gt;)
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6334</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6335
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6336<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6337<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
6338 function pointer suitable for executing it.</p>
6339
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6340<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6341<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
6342 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
6343 sufficiently aligned block of memory; this memory is written to by the
6344 intrinsic. Note that the size and the alignment are target-specific - LLVM
6345 currently provides no portable way of determining them, so a front-end that
6346 generates this intrinsic needs to have some target-specific knowledge.
6347 The <tt>func</tt> argument must hold a function bitcast to
6348 an <tt>i8*</tt>.</p>
6349
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6350<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6351<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
6352 dependent code, turning it into a function. A pointer to this function is
6353 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
6354 function pointer type</a> before being called. The new function's signature
6355 is the same as that of <tt>func</tt> with any arguments marked with
6356 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
6357 is allowed, and it must be of pointer type. Calling the new function is
6358 equivalent to calling <tt>func</tt> with the same argument list, but
6359 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
6360 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
6361 by <tt>tramp</tt> is modified, then the effect of any later call to the
6362 returned function pointer is undefined.</p>
6363
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6364</div>
6365
6366<!-- ======================================================================= -->
6367<div class="doc_subsection">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6368 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
6369</div>
6370
6371<div class="doc_text">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6372
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6373<p>These intrinsic functions expand the "universal IR" of LLVM to represent
6374 hardware constructs for atomic operations and memory synchronization. This
6375 provides an interface to the hardware, not an interface to the programmer. It
6376 is aimed at a low enough level to allow any programming models or APIs
6377 (Application Programming Interfaces) which need atomic behaviors to map
6378 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
6379 hardware provides a "universal IR" for source languages, it also provides a
6380 starting point for developing a "universal" atomic operation and
6381 synchronization IR.</p>
6382
6383<p>These do <em>not</em> form an API such as high-level threading libraries,
6384 software transaction memory systems, atomic primitives, and intrinsic
6385 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
6386 application libraries. The hardware interface provided by LLVM should allow
6387 a clean implementation of all of these APIs and parallel programming models.
6388 No one model or paradigm should be selected above others unless the hardware
6389 itself ubiquitously does so.</p>
6390
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6391</div>
6392
6393<!-- _______________________________________________________________________ -->
6394<div class="doc_subsubsection">
6395 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
6396</div>
6397<div class="doc_text">
6398<h5>Syntax:</h5>
6399<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6400 declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;, i1 &lt;device&gt; )
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6401</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6402
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6403<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6404<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
6405 specific pairs of memory access types.</p>
6406
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6407<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6408<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
6409 The first four arguments enables a specific barrier as listed below. The
6410 fith argument specifies that the barrier applies to io or device or uncached
6411 memory.</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6412
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6413<ul>
6414 <li><tt>ll</tt>: load-load barrier</li>
6415 <li><tt>ls</tt>: load-store barrier</li>
6416 <li><tt>sl</tt>: store-load barrier</li>
6417 <li><tt>ss</tt>: store-store barrier</li>
6418 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
6419</ul>
6420
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6421<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6422<p>This intrinsic causes the system to enforce some ordering constraints upon
6423 the loads and stores of the program. This barrier does not
6424 indicate <em>when</em> any events will occur, it only enforces
6425 an <em>order</em> in which they occur. For any of the specified pairs of load
6426 and store operations (f.ex. load-load, or store-load), all of the first
6427 operations preceding the barrier will complete before any of the second
6428 operations succeeding the barrier begin. Specifically the semantics for each
6429 pairing is as follows:</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6430
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6431<ul>
6432 <li><tt>ll</tt>: All loads before the barrier must complete before any load
6433 after the barrier begins.</li>
6434 <li><tt>ls</tt>: All loads before the barrier must complete before any
6435 store after the barrier begins.</li>
6436 <li><tt>ss</tt>: All stores before the barrier must complete before any
6437 store after the barrier begins.</li>
6438 <li><tt>sl</tt>: All stores before the barrier must complete before any
6439 load after the barrier begins.</li>
6440</ul>
6441
6442<p>These semantics are applied with a logical "and" behavior when more than one
6443 is enabled in a single memory barrier intrinsic.</p>
6444
6445<p>Backends may implement stronger barriers than those requested when they do
6446 not support as fine grained a barrier as requested. Some architectures do
6447 not need all types of barriers and on such architectures, these become
6448 noops.</p>
6449
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6450<h5>Example:</h5>
6451<pre>
6452%ptr = malloc i32
6453 store i32 4, %ptr
6454
6455%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
6456 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
6457 <i>; guarantee the above finishes</i>
6458 store i32 8, %ptr <i>; before this begins</i>
6459</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6460
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6461</div>
6462
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6463<!-- _______________________________________________________________________ -->
6464<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6465 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6466</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6467
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6468<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6469
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6470<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6471<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
6472 any integer bit width and for different address spaces. Not all targets
6473 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6474
6475<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6476 declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6477 declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6478 declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
6479 declare i64 @llvm.atomic.cmp.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;cmp&gt;, i64 &lt;val&gt; )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6480</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6481
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6482<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6483<p>This loads a value in memory and compares it to a given value. If they are
6484 equal, it stores a new value into the memory.</p>
6485
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6486<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6487<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
6488 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
6489 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
6490 this integer type. While any bit width integer may be used, targets may only
6491 lower representations they support in hardware.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6492
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6493<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6494<p>This entire intrinsic must be executed atomically. It first loads the value
6495 in memory pointed to by <tt>ptr</tt> and compares it with the
6496 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
6497 memory. The loaded value is yielded in all cases. This provides the
6498 equivalent of an atomic compare-and-swap operation within the SSA
6499 framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6500
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6501<h5>Examples:</h5>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6502<pre>
6503%ptr = malloc i32
6504 store i32 4, %ptr
6505
6506%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6507%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6508 <i>; yields {i32}:result1 = 4</i>
6509%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6510%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6511
6512%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6513%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6514 <i>; yields {i32}:result2 = 8</i>
6515%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6516
6517%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6518</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6519
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6520</div>
6521
6522<!-- _______________________________________________________________________ -->
6523<div class="doc_subsubsection">
6524 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6525</div>
6526<div class="doc_text">
6527<h5>Syntax:</h5>
6528
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6529<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6530 integer bit width. Not all targets support all bit widths however.</p>
6531
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6532<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6533 declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6534 declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6535 declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6536 declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6537</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6538
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6539<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6540<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6541 the value from memory. It then stores the value in <tt>val</tt> in the memory
6542 at <tt>ptr</tt>.</p>
6543
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6544<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6545<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
6546 the <tt>val</tt> argument and the result must be integers of the same bit
6547 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6548 integer type. The targets may only lower integer representations they
6549 support.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6550
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6551<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6552<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6553 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6554 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6555
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6556<h5>Examples:</h5>
6557<pre>
6558%ptr = malloc i32
6559 store i32 4, %ptr
6560
6561%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6562%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6563 <i>; yields {i32}:result1 = 4</i>
6564%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6565%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6566
6567%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6568%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6569 <i>; yields {i32}:result2 = 8</i>
6570
6571%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6572%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6573</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6574
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6575</div>
6576
6577<!-- _______________________________________________________________________ -->
6578<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6579 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6580
6581</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6582
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6583<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6584
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6585<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6586<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
6587 any integer bit width. Not all targets support all bit widths however.</p>
6588
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6589<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6590 declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6591 declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6592 declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6593 declare i64 @llvm.atomic.load.add.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6594</pre>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6595
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6596<h5>Overview:</h5>
6597<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
6598 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6599
6600<h5>Arguments:</h5>
6601<p>The intrinsic takes two arguments, the first a pointer to an integer value
6602 and the second an integer value. The result is also an integer value. These
6603 integer types can have any bit width, but they must all have the same bit
6604 width. The targets may only lower integer representations they support.</p>
6605
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6606<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6607<p>This intrinsic does a series of operations atomically. It first loads the
6608 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6609 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6610
6611<h5>Examples:</h5>
6612<pre>
6613%ptr = malloc i32
6614 store i32 4, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6615%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6616 <i>; yields {i32}:result1 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6617%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6618 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6619%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6620 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6621%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6622</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6623
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6624</div>
6625
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6626<!-- _______________________________________________________________________ -->
6627<div class="doc_subsubsection">
6628 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6629
6630</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6631
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6632<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6633
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6634<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6635<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
6636 any integer bit width and for different address spaces. Not all targets
6637 support all bit widths however.</p>
6638
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6639<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6640 declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6641 declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6642 declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6643 declare i64 @llvm.atomic.load.sub.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6644</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6645
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6646<h5>Overview:</h5>
6647<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6648 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6649
6650<h5>Arguments:</h5>
6651<p>The intrinsic takes two arguments, the first a pointer to an integer value
6652 and the second an integer value. The result is also an integer value. These
6653 integer types can have any bit width, but they must all have the same bit
6654 width. The targets may only lower integer representations they support.</p>
6655
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6656<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6657<p>This intrinsic does a series of operations atomically. It first loads the
6658 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6659 result to <tt>ptr</tt>. It yields the original value stored
6660 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6661
6662<h5>Examples:</h5>
6663<pre>
6664%ptr = malloc i32
6665 store i32 8, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6666%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6667 <i>; yields {i32}:result1 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6668%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6669 <i>; yields {i32}:result2 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6670%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6671 <i>; yields {i32}:result3 = 2</i>
6672%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6673</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6674
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6675</div>
6676
6677<!-- _______________________________________________________________________ -->
6678<div class="doc_subsubsection">
6679 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6680 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6681 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6682 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6683</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6684
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6685<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6686
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6687<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6688<p>These are overloaded intrinsics. You can
6689 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
6690 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
6691 bit width and for different address spaces. Not all targets support all bit
6692 widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6693
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6694<pre>
6695 declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6696 declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6697 declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6698 declare i64 @llvm.atomic.load.and.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6699</pre>
6700
6701<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6702 declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6703 declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6704 declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6705 declare i64 @llvm.atomic.load.or.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6706</pre>
6707
6708<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6709 declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6710 declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6711 declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6712 declare i64 @llvm.atomic.load.nand.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6713</pre>
6714
6715<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6716 declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6717 declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6718 declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6719 declare i64 @llvm.atomic.load.xor.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6720</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6721
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6722<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6723<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6724 the value stored in memory at <tt>ptr</tt>. It yields the original value
6725 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6726
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6727<h5>Arguments:</h5>
6728<p>These intrinsics take two arguments, the first a pointer to an integer value
6729 and the second an integer value. The result is also an integer value. These
6730 integer types can have any bit width, but they must all have the same bit
6731 width. The targets may only lower integer representations they support.</p>
6732
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6733<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6734<p>These intrinsics does a series of operations atomically. They first load the
6735 value stored at <tt>ptr</tt>. They then do the bitwise
6736 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
6737 original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6738
6739<h5>Examples:</h5>
6740<pre>
6741%ptr = malloc i32
6742 store i32 0x0F0F, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6743%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6744 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6745%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6746 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6747%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6748 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6749%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6750 <i>; yields {i32}:result3 = FF</i>
6751%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6752</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6753
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6754</div>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6755
6756<!-- _______________________________________________________________________ -->
6757<div class="doc_subsubsection">
6758 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6759 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6760 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6761 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6762</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6763
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6764<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6765
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6766<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6767<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6768 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
6769 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6770 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6771
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6772<pre>
6773 declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6774 declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6775 declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6776 declare i64 @llvm.atomic.load.max.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6777</pre>
6778
6779<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6780 declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6781 declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6782 declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6783 declare i64 @llvm.atomic.load.min.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6784</pre>
6785
6786<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6787 declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6788 declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6789 declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6790 declare i64 @llvm.atomic.load.umax.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6791</pre>
6792
6793<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6794 declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6795 declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6796 declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6797 declare i64 @llvm.atomic.load.umin.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6798</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6799
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6800<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6801<p>These intrinsics takes the signed or unsigned minimum or maximum of
6802 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6803 original value at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6804
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6805<h5>Arguments:</h5>
6806<p>These intrinsics take two arguments, the first a pointer to an integer value
6807 and the second an integer value. The result is also an integer value. These
6808 integer types can have any bit width, but they must all have the same bit
6809 width. The targets may only lower integer representations they support.</p>
6810
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6811<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6812<p>These intrinsics does a series of operations atomically. They first load the
6813 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
6814 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
6815 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6816
6817<h5>Examples:</h5>
6818<pre>
6819%ptr = malloc i32
6820 store i32 7, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6821%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6822 <i>; yields {i32}:result0 = 7</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6823%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6824 <i>; yields {i32}:result1 = -2</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6825%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6826 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6827%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6828 <i>; yields {i32}:result3 = 8</i>
6829%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6830</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6831
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6832</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6833
6834<!-- ======================================================================= -->
6835<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6836 <a name="int_general">General Intrinsics</a>
6837</div>
6838
6839<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6840
6841<p>This class of intrinsics is designed to be generic and has no specific
6842 purpose.</p>
6843
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6844</div>
6845
6846<!-- _______________________________________________________________________ -->
6847<div class="doc_subsubsection">
6848 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6849</div>
6850
6851<div class="doc_text">
6852
6853<h5>Syntax:</h5>
6854<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]6855 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]6856</pre>
6857
6858<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6859<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6860
6861<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6862<p>The first argument is a pointer to a value, the second is a pointer to a
6863 global string, the third is a pointer to a global string which is the source
6864 file name, and the last argument is the line number.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6865
6866<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6867<p>This intrinsic allows annotation of local variables with arbitrary strings.
6868 This can be useful for special purpose optimizations that want to look for
6869 these annotations. These have no other defined use, they are ignored by code
6870 generation and optimization.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6871
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6872</div>
6873
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6874<!-- _______________________________________________________________________ -->
6875<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]6876 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6877</div>
6878
6879<div class="doc_text">
6880
6881<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6882<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6883 any integer bit width.</p>
6884
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6885<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]6886 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6887 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6888 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6889 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6890 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]6891</pre>
6892
6893<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6894<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6895
6896<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6897<p>The first argument is an integer value (result of some expression), the
6898 second is a pointer to a global string, the third is a pointer to a global
6899 string which is the source file name, and the last argument is the line
6900 number. It returns the value of the first argument.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6901
6902<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6903<p>This intrinsic allows annotations to be put on arbitrary expressions with
6904 arbitrary strings. This can be useful for special purpose optimizations that
6905 want to look for these annotations. These have no other defined use, they
6906 are ignored by code generation and optimization.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6907
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6908</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6909
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6910<!-- _______________________________________________________________________ -->
6911<div class="doc_subsubsection">
6912 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6913</div>
6914
6915<div class="doc_text">
6916
6917<h5>Syntax:</h5>
6918<pre>
6919 declare void @llvm.trap()
6920</pre>
6921
6922<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6923<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6924
6925<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6926<p>None.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6927
6928<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6929<p>This intrinsics is lowered to the target dependent trap instruction. If the
6930 target does not have a trap instruction, this intrinsic will be lowered to
6931 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6932
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6933</div>
6934
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6935<!-- _______________________________________________________________________ -->
6936<div class="doc_subsubsection">
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]6937 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6938</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6939
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6940<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6941
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6942<h5>Syntax:</h5>
6943<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6944 declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6945</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6946
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6947<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6948<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
6949 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
6950 ensure that it is placed on the stack before local variables.</p>
6951
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6952<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6953<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
6954 arguments. The first argument is the value loaded from the stack
6955 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
6956 that has enough space to hold the value of the guard.</p>
6957
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6958<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6959<p>This intrinsic causes the prologue/epilogue inserter to force the position of
6960 the <tt>AllocaInst</tt> stack slot to be before local variables on the
6961 stack. This is to ensure that if a local variable on the stack is
6962 overwritten, it will destroy the value of the guard. When the function exits,
6963 the guard on the stack is checked against the original guard. If they're
6964 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
6965 function.</p>
6966
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6967</div>
6968
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6969<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6970<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6971<address>
6972 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]6973 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6974 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]6975 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6976
6977 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]6978 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6979 Last modified: $Date$
6980</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]6981
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6982</body>
6983</html>