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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 19527c6ef371c6a09743bf91d4bee36b32241b12 / . / 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>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a></li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]24 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]25 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]26 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]27 <li><a href="#functionstructure">Functions</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]28 <li><a href="#aliasstructure">Aliases</a></li>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]29 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]30 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]31 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]32 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]33 <li><a href="#datalayout">Data Layout</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]34 </ol>
35 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]36 <li><a href="#typesystem">Type System</a>
37 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]38 <li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]39 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]40 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]41 <li><a href="#t_floating">Floating Point Types</a></li>
42 <li><a href="#t_void">Void Type</a></li>
43 <li><a href="#t_label">Label Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]44 </ol>
45 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]46 <li><a href="#t_derived">Derived Types</a>
47 <ol>
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]48 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]49 <li><a href="#t_array">Array Type</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]50 <li><a href="#t_function">Function Type</a></li>
51 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]52 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]53 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]54 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]55 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]56 </ol>
57 </li>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]58 <li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]59 </ol>
60 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]61 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]62 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]63 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]64 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]65 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
66 <li><a href="#undefvalues">Undefined Values</a></li>
67 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]68 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]69 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]70 <li><a href="#othervalues">Other Values</a>
71 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]72 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]73 </ol>
74 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]75 <li><a href="#instref">Instruction Reference</a>
76 <ol>
77 <li><a href="#terminators">Terminator Instructions</a>
78 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]79 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
80 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]81 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
82 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]83 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]84 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]85 </ol>
86 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]87 <li><a href="#binaryops">Binary Operations</a>
88 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]89 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
90 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
91 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]92 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
93 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
94 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]95 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
96 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
97 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]98 </ol>
99 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]100 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
101 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]102 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
103 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
104 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]105 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]106 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]107 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]108 </ol>
109 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]110 <li><a href="#vectorops">Vector Operations</a>
111 <ol>
112 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
113 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
114 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]115 </ol>
116 </li>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]117 <li><a href="#aggregateops">Aggregate Operations</a>
118 <ol>
119 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
120 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
121 </ol>
122 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]123 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]124 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]125 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
126 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
127 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]128 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
129 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
130 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]131 </ol>
132 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]133 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]134 <ol>
135 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
136 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
137 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
138 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
139 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]140 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
141 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
142 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
143 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]144 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
145 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]146 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]147 </ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]148 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]149 <li><a href="#otherops">Other Operations</a>
150 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]151 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
152 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]153 <li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
154 <li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]155 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]156 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]157 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]158 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]159 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]160 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]161 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]162 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]163 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]164 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]165 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
166 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]167 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
168 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
169 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]170 </ol>
171 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]172 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
173 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]174 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
175 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
176 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]177 </ol>
178 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]179 <li><a href="#int_codegen">Code Generator Intrinsics</a>
180 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]181 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
182 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
183 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
184 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
185 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
186 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
187 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]188 </ol>
189 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]190 <li><a href="#int_libc">Standard C Library Intrinsics</a>
191 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]192 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
193 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
194 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
195 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
196 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]197 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
198 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
199 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]200 </ol>
201 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]202 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]203 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]204 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]205 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
206 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
207 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]208 <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
209 <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]210 </ol>
211 </li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]212 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
213 <ol>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]214 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
215 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
216 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
217 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
218 <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]219 <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]220 </ol>
221 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]222 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]223 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]224 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]225 <ol>
226 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]227 </ol>
228 </li>
Bill Wendling3c44f5b2008-11-18 22:10:53 +0000[diff] [blame]229 <li><a href="#int_atomics">Atomic intrinsics</a>
230 <ol>
231 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
232 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
233 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
234 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
235 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
236 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
237 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
238 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
239 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
240 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
241 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
242 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
243 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
244 </ol>
245 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]246 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]247 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]248 <li><a href="#int_var_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]249 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]250 <li><a href="#int_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]251 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]252 <li><a href="#int_trap">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]253 '<tt>llvm.trap</tt>' Intrinsic</a></li>
254 <li><a href="#int_stackprotector">
255 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]256 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]257 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]258 </ol>
259 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]260</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]261
262<div class="doc_author">
263 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
264 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]265</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]266
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]267<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]268<div class="doc_section"> <a name="abstract">Abstract </a></div>
269<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]270
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]271<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]272<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling837f39b2008-08-05 22:29:16 +0000[diff] [blame]273LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]274type safety, low-level operations, flexibility, and the capability of
275representing 'all' high-level languages cleanly. It is the common code
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]276representation used throughout all phases of the LLVM compilation
277strategy.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]278</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]279
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]280<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]281<div class="doc_section"> <a name="introduction">Introduction</a> </div>
282<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]283
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]284<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]285
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]286<p>The LLVM code representation is designed to be used in three
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]287different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]288representation (suitable for fast loading by a Just-In-Time compiler),
289and as a human readable assembly language representation. This allows
290LLVM to provide a powerful intermediate representation for efficient
291compiler transformations and analysis, while providing a natural means
292to debug and visualize the transformations. The three different forms
293of LLVM are all equivalent. This document describes the human readable
294representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]295
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]296<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]297while being expressive, typed, and extensible at the same time. It
298aims to be a "universal IR" of sorts, by being at a low enough level
299that high-level ideas may be cleanly mapped to it (similar to how
300microprocessors are "universal IR's", allowing many source languages to
301be mapped to them). By providing type information, LLVM can be used as
302the target of optimizations: for example, through pointer analysis, it
303can be proven that a C automatic variable is never accessed outside of
304the current function... allowing it to be promoted to a simple SSA
305value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]306
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]307</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]308
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]309<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]310<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]311
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]312<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]313
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]314<p>It is important to note that this document describes 'well formed'
315LLVM assembly language. There is a difference between what the parser
316accepts and what is considered 'well formed'. For example, the
317following instruction is syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]318
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]319<div class="doc_code">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]320<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]321%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]322</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]323</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]324
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]325<p>...because the definition of <tt>%x</tt> does not dominate all of
326its uses. The LLVM infrastructure provides a verification pass that may
327be used to verify that an LLVM module is well formed. This pass is
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]328automatically run by the parser after parsing input assembly and by
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]329the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]330by the verifier pass indicate bugs in transformation passes or input to
331the parser.</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]332</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]333
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]334<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]335
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]336<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]337<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]338<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]339
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]340<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]341
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]342 <p>LLVM identifiers come in two basic types: global and local. Global
343 identifiers (functions, global variables) begin with the @ character. Local
344 identifiers (register names, types) begin with the % character. Additionally,
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]345 there are three different formats for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]346
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]347<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]348 <li>Named values are represented as a string of characters with their prefix.
349 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
350 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]351 Identifiers which require other characters in their names can be surrounded
Daniel Dunbar76dea952008-10-14 23:51:43 +0000[diff] [blame]352 with quotes. Special characters may be escaped using "\xx" where xx is the
353 ASCII code for the character in hexadecimal. In this way, any character can
354 be used in a name value, even quotes themselves.
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]355
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]356 <li>Unnamed values are represented as an unsigned numeric value with their
357 prefix. For example, %12, @2, %44.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]358
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]359 <li>Constants, which are described in a <a href="#constants">section about
360 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]361</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]362
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]363<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]364don't need to worry about name clashes with reserved words, and the set of
365reserved words may be expanded in the future without penalty. Additionally,
366unnamed identifiers allow a compiler to quickly come up with a temporary
367variable without having to avoid symbol table conflicts.</p>
368
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]369<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]370languages. There are keywords for different opcodes
371('<tt><a href="#i_add">add</a></tt>',
372 '<tt><a href="#i_bitcast">bitcast</a></tt>',
373 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names ('<tt><a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]374href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]375and others. These reserved words cannot conflict with variable names, because
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]376none of them start with a prefix character ('%' or '@').</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]377
378<p>Here is an example of LLVM code to multiply the integer variable
379'<tt>%X</tt>' by 8:</p>
380
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]381<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]382
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]383<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]384<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]385%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]386</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]387</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]388
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]389<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]390
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]391<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]392<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]393%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]394</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]395</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]396
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]397<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]398
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]399<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]400<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]401<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
402<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
403%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]404</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]405</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]406
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]407<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
408important lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]409
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]410<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]411
412 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
413 line.</li>
414
415 <li>Unnamed temporaries are created when the result of a computation is not
416 assigned to a named value.</li>
417
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]418 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]419
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]420</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]421
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]422<p>...and it also shows a convention that we follow in this document. When
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]423demonstrating instructions, we will follow an instruction with a comment that
424defines the type and name of value produced. Comments are shown in italic
425text.</p>
426
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]427</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]428
429<!-- *********************************************************************** -->
430<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
431<!-- *********************************************************************** -->
432
433<!-- ======================================================================= -->
434<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
435</div>
436
437<div class="doc_text">
438
439<p>LLVM programs are composed of "Module"s, each of which is a
440translation unit of the input programs. Each module consists of
441functions, global variables, and symbol table entries. Modules may be
442combined together with the LLVM linker, which merges function (and
443global variable) definitions, resolves forward declarations, and merges
444symbol table entries. Here is an example of the "hello world" module:</p>
445
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]446<div class="doc_code">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]447<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]448<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
449 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]450
451<i>; External declaration of the puts function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]452<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]453
454<i>; Definition of main function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]455define i32 @main() { <i>; i32()* </i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]456 <i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]457 %cast210 = <a
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]458 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]459
460 <i>; Call puts function to write out the string to stdout...</i>
461 <a
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]462 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]463 <a
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]464 href="#i_ret">ret</a> i32 0<br>}<br>
465</pre>
466</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]467
468<p>This example is made up of a <a href="#globalvars">global variable</a>
469named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
470function, and a <a href="#functionstructure">function definition</a>
471for "<tt>main</tt>".</p>
472
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]473<p>In general, a module is made up of a list of global values,
474where both functions and global variables are global values. Global values are
475represented by a pointer to a memory location (in this case, a pointer to an
476array of char, and a pointer to a function), and have one of the following <a
477href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]478
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]479</div>
480
481<!-- ======================================================================= -->
482<div class="doc_subsection">
483 <a name="linkage">Linkage Types</a>
484</div>
485
486<div class="doc_text">
487
488<p>
489All Global Variables and Functions have one of the following types of linkage:
490</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]491
492<dl>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]493
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]494 <dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
495
496 <dd>Global values with private linkage are only directly accessible by
497 objects in the current module. In particular, linking code into a module with
498 an private global value may cause the private to be renamed as necessary to
499 avoid collisions. Because the symbol is private to the module, all
500 references can be updated. This doesn't show up in any symbol table in the
501 object file.
502 </dd>
503
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]504 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]505
Duncan Sands81d05c22009-01-16 09:29:46 +0000[diff] [blame]506 <dd> Similar to private, but the value shows as a local symbol (STB_LOCAL in
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]507 the case of ELF) in the object file. This corresponds to the notion of the
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]508 '<tt>static</tt>' keyword in C.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]509 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]510
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]511 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]512
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]513 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
514 the same name when linkage occurs. This is typically used to implement
515 inline functions, templates, or other code which must be generated in each
516 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
517 allowed to be discarded.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]518 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]519
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]520 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
521
522 <dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
523 linkage, except that unreferenced <tt>common</tt> globals may not be
524 discarded. This is used for globals that may be emitted in multiple
525 translation units, but that are not guaranteed to be emitted into every
526 translation unit that uses them. One example of this is tentative
527 definitions in C, such as "<tt>int X;</tt>" at global scope.
528 </dd>
529
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]530 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]531
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]532 <dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
533 that some targets may choose to emit different assembly sequences for them
534 for target-dependent reasons. This is used for globals that are declared
535 "weak" in C source code.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]536 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]537
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]538 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]539
540 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
541 pointer to array type. When two global variables with appending linkage are
542 linked together, the two global arrays are appended together. This is the
543 LLVM, typesafe, equivalent of having the system linker append together
544 "sections" with identical names when .o files are linked.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]545 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]546
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]547 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]548
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]549 <dd>The semantics of this linkage follow the ELF object file model: the
550 symbol is weak until linked, if not linked, the symbol becomes null instead
551 of being an undefined reference.
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]552 </dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]553
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]554 <dt><tt><b><a name="linkage_linkonce">linkonce_odr</a></b></tt>: </dt>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]555 <dt><tt><b><a name="linkage_weak">weak_odr</a></b></tt>: </dt>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]556 <dd>Some languages allow inequivalent globals to be merged, such as two
557 functions with different semantics. Other languages, such as <tt>C++</tt>,
558 ensure that only equivalent globals are ever merged (the "one definition
Duncan Sands4dc2b392009-03-11 20:14:15 +0000[diff] [blame]559 rule" - <tt>odr</tt>). Such languages can use the <tt>linkonce_odr</tt>
560 and <tt>weak_odr</tt> linkage types to indicate that the global will only
561 be merged with equivalent globals. These linkage types are otherwise the
562 same as their non-<tt>odr</tt> versions.
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]563 </dd>
564
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]565 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]566
567 <dd>If none of the above identifiers are used, the global is externally
568 visible, meaning that it participates in linkage and can be used to resolve
569 external symbol references.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]570 </dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]571</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]572
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]573 <p>
574 The next two types of linkage are targeted for Microsoft Windows platform
575 only. They are designed to support importing (exporting) symbols from (to)
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]576 DLLs (Dynamic Link Libraries).
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]577 </p>
578
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]579 <dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]580 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
581
582 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
583 or variable via a global pointer to a pointer that is set up by the DLL
584 exporting the symbol. On Microsoft Windows targets, the pointer name is
Dan Gohman79564122009-01-12 21:35:55 +0000[diff] [blame]585 formed by combining <code>__imp_</code> and the function or variable name.
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]586 </dd>
587
588 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
589
590 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
591 pointer to a pointer in a DLL, so that it can be referenced with the
592 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
Dan Gohman79564122009-01-12 21:35:55 +0000[diff] [blame]593 name is formed by combining <code>__imp_</code> and the function or variable
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]594 name.
595 </dd>
596
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]597</dl>
598
Dan Gohmanf0032762008-11-24 17:18:39 +0000[diff] [blame]599<p>For example, since the "<tt>.LC0</tt>"
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]600variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
601variable and was linked with this one, one of the two would be renamed,
602preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
603external (i.e., lacking any linkage declarations), they are accessible
Reid Spencerac8d2762007-01-05 00:59:10 +0000[diff] [blame]604outside of the current module.</p>
605<p>It is illegal for a function <i>declaration</i>
Duncan Sands5f4ee1f2009-03-11 08:08:06 +0000[diff] [blame]606to have any linkage type other than "externally visible", <tt>dllimport</tt>
607or <tt>extern_weak</tt>.</p>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]608<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
609or <tt>weak_odr</tt> linkages.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]610</div>
611
612<!-- ======================================================================= -->
613<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]614 <a name="callingconv">Calling Conventions</a>
615</div>
616
617<div class="doc_text">
618
619<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
620and <a href="#i_invoke">invokes</a> can all have an optional calling convention
621specified for the call. The calling convention of any pair of dynamic
622caller/callee must match, or the behavior of the program is undefined. The
623following calling conventions are supported by LLVM, and more may be added in
624the future:</p>
625
626<dl>
627 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
628
629 <dd>This calling convention (the default if no other calling convention is
630 specified) matches the target C calling conventions. This calling convention
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]631 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencerc28d2bc2006-12-31 21:30:18 +0000[diff] [blame]632 prototype and implemented declaration of the function (as does normal C).
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]633 </dd>
634
635 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
636
637 <dd>This calling convention attempts to make calls as fast as possible
638 (e.g. by passing things in registers). This calling convention allows the
639 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]640 without having to conform to an externally specified ABI (Application Binary
641 Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer9097d142008-05-14 09:17:12 +0000[diff] [blame]642 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
643 supported. This calling convention does not support varargs and requires the
644 prototype of all callees to exactly match the prototype of the function
645 definition.
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]646 </dd>
647
648 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
649
650 <dd>This calling convention attempts to make code in the caller as efficient
651 as possible under the assumption that the call is not commonly executed. As
652 such, these calls often preserve all registers so that the call does not break
653 any live ranges in the caller side. This calling convention does not support
654 varargs and requires the prototype of all callees to exactly match the
655 prototype of the function definition.
656 </dd>
657
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]658 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]659
660 <dd>Any calling convention may be specified by number, allowing
661 target-specific calling conventions to be used. Target specific calling
662 conventions start at 64.
663 </dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]664</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]665
666<p>More calling conventions can be added/defined on an as-needed basis, to
667support pascal conventions or any other well-known target-independent
668convention.</p>
669
670</div>
671
672<!-- ======================================================================= -->
673<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]674 <a name="visibility">Visibility Styles</a>
675</div>
676
677<div class="doc_text">
678
679<p>
680All Global Variables and Functions have one of the following visibility styles:
681</p>
682
683<dl>
684 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
685
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]686 <dd>On targets that use the ELF object file format, default visibility means
687 that the declaration is visible to other
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]688 modules and, in shared libraries, means that the declared entity may be
689 overridden. On Darwin, default visibility means that the declaration is
690 visible to other modules. Default visibility corresponds to "external
691 linkage" in the language.
692 </dd>
693
694 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
695
696 <dd>Two declarations of an object with hidden visibility refer to the same
697 object if they are in the same shared object. Usually, hidden visibility
698 indicates that the symbol will not be placed into the dynamic symbol table,
699 so no other module (executable or shared library) can reference it
700 directly.
701 </dd>
702
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]703 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
704
705 <dd>On ELF, protected visibility indicates that the symbol will be placed in
706 the dynamic symbol table, but that references within the defining module will
707 bind to the local symbol. That is, the symbol cannot be overridden by another
708 module.
709 </dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]710</dl>
711
712</div>
713
714<!-- ======================================================================= -->
715<div class="doc_subsection">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]716 <a name="namedtypes">Named Types</a>
717</div>
718
719<div class="doc_text">
720
721<p>LLVM IR allows you to specify name aliases for certain types. This can make
722it easier to read the IR and make the IR more condensed (particularly when
723recursive types are involved). An example of a name specification is:
724</p>
725
726<div class="doc_code">
727<pre>
728%mytype = type { %mytype*, i32 }
729</pre>
730</div>
731
732<p>You may give a name to any <a href="#typesystem">type</a> except "<a
733href="t_void">void</a>". Type name aliases may be used anywhere a type is
734expected with the syntax "%mytype".</p>
735
736<p>Note that type names are aliases for the structural type that they indicate,
737and that you can therefore specify multiple names for the same type. This often
738leads to confusing behavior when dumping out a .ll file. Since LLVM IR uses
739structural typing, the name is not part of the type. When printing out LLVM IR,
740the printer will pick <em>one name</em> to render all types of a particular
741shape. This means that if you have code where two different source types end up
742having the same LLVM type, that the dumper will sometimes print the "wrong" or
743unexpected type. This is an important design point and isn't going to
744change.</p>
745
746</div>
747
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]748<!-- ======================================================================= -->
749<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]750 <a name="globalvars">Global Variables</a>
751</div>
752
753<div class="doc_text">
754
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]755<p>Global variables define regions of memory allocated at compilation time
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]756instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]757an explicit section to be placed in, and may have an optional explicit alignment
758specified. A variable may be defined as "thread_local", which means that it
759will not be shared by threads (each thread will have a separated copy of the
760variable). A variable may be defined as a global "constant," which indicates
761that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]762optimization, allowing the global data to be placed in the read-only section of
763an executable, etc). Note that variables that need runtime initialization
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]764cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]765
766<p>
767LLVM explicitly allows <em>declarations</em> of global variables to be marked
768constant, even if the final definition of the global is not. This capability
769can be used to enable slightly better optimization of the program, but requires
770the language definition to guarantee that optimizations based on the
771'constantness' are valid for the translation units that do not include the
772definition.
773</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]774
775<p>As SSA values, global variables define pointer values that are in
776scope (i.e. they dominate) all basic blocks in the program. Global
777variables always define a pointer to their "content" type because they
778describe a region of memory, and all memory objects in LLVM are
779accessed through pointers.</p>
780
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]781<p>A global variable may be declared to reside in a target-specifc numbered
782address space. For targets that support them, address spaces may affect how
783optimizations are performed and/or what target instructions are used to access
Christopher Lambd49e18d2007-12-12 08:44:39 +0000[diff] [blame]784the variable. The default address space is zero. The address space qualifier
785must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]786
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]787<p>LLVM allows an explicit section to be specified for globals. If the target
788supports it, it will emit globals to the section specified.</p>
789
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]790<p>An explicit alignment may be specified for a global. If not present, or if
791the alignment is set to zero, the alignment of the global is set by the target
792to whatever it feels convenient. If an explicit alignment is specified, the
793global is forced to have at least that much alignment. All alignments must be
794a power of 2.</p>
795
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]796<p>For example, the following defines a global in a numbered address space with
797an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]798
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]799<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]800<pre>
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]801@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]802</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]803</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]804
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]805</div>
806
807
808<!-- ======================================================================= -->
809<div class="doc_subsection">
810 <a name="functionstructure">Functions</a>
811</div>
812
813<div class="doc_text">
814
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]815<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
816an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]817<a href="#visibility">visibility style</a>, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]818<a href="#callingconv">calling convention</a>, a return type, an optional
819<a href="#paramattrs">parameter attribute</a> for the return type, a function
820name, a (possibly empty) argument list (each with optional
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]821<a href="#paramattrs">parameter attributes</a>), optional
822<a href="#fnattrs">function attributes</a>, an optional section,
823an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner0c46a7d2008-10-04 18:10:21 +0000[diff] [blame]824an opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]825
826LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
827optional <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
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]830<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]831name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksene754abe2007-12-10 03:30:21 +0000[diff] [blame]832<a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]833
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]834<p>A function definition contains a list of basic blocks, forming the CFG
835(Control Flow Graph) for
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]836the function. Each basic block may optionally start with a label (giving the
837basic block a symbol table entry), contains a list of instructions, and ends
838with a <a href="#terminators">terminator</a> instruction (such as a branch or
839function return).</p>
840
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]841<p>The first basic block in a function is special in two ways: it is immediately
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]842executed on entrance to the function, and it is not allowed to have predecessor
843basic blocks (i.e. there can not be any branches to the entry block of a
844function). Because the block can have no predecessors, it also cannot have any
845<a href="#i_phi">PHI nodes</a>.</p>
846
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]847<p>LLVM allows an explicit section to be specified for functions. If the target
848supports it, it will emit functions to the section specified.</p>
849
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]850<p>An explicit alignment may be specified for a function. If not present, or if
851the alignment is set to zero, the alignment of the function is set by the target
852to whatever it feels convenient. If an explicit alignment is specified, the
853function is forced to have at least that much alignment. All alignments must be
854a power of 2.</p>
855
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]856 <h5>Syntax:</h5>
857
858<div class="doc_code">
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]859<tt>
860define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
861 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
862 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
863 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
864 [<a href="#gc">gc</a>] { ... }
865</tt>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]866</div>
867
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]868</div>
869
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]870
871<!-- ======================================================================= -->
872<div class="doc_subsection">
873 <a name="aliasstructure">Aliases</a>
874</div>
875<div class="doc_text">
876 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov726d45c2008-03-22 08:36:14 +0000[diff] [blame]877 function, global variable, another alias or bitcast of global value). Aliases
878 may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]879 optional <a href="#visibility">visibility style</a>.</p>
880
881 <h5>Syntax:</h5>
882
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]883<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]884<pre>
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]885@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]886</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]887</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]888
889</div>
890
891
892
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]893<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]894<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
895<div class="doc_text">
896 <p>The return type and each parameter of a function type may have a set of
897 <i>parameter attributes</i> associated with them. Parameter attributes are
898 used to communicate additional information about the result or parameters of
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]899 a function. Parameter attributes are considered to be part of the function,
900 not of the function type, so functions with different parameter attributes
901 can have the same function type.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]902
Reid Spencer950e9f82007-01-15 18:27:39 +0000[diff] [blame]903 <p>Parameter attributes are simple keywords that follow the type specified. If
904 multiple parameter attributes are needed, they are space separated. For
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]905 example:</p>
906
907<div class="doc_code">
908<pre>
Nick Lewyckyb6a7d252009-02-15 23:06:14 +0000[diff] [blame]909declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]910declare i32 @atoi(i8 zeroext)
911declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]912</pre>
913</div>
914
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]915 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
916 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]917
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]918 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]919 <dl>
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]920 <dt><tt>zeroext</tt></dt>
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]921 <dd>This indicates to the code generator that the parameter or return value
922 should be zero-extended to a 32-bit value by the caller (for a parameter)
923 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]924
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]925 <dt><tt>signext</tt></dt>
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]926 <dd>This indicates to the code generator that the parameter or return value
927 should be sign-extended to a 32-bit value by the caller (for a parameter)
928 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]929
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]930 <dt><tt>inreg</tt></dt>
Dale Johannesenc9c6da62008-09-25 20:47:45 +0000[diff] [blame]931 <dd>This indicates that this parameter or return value should be treated
932 in a special target-dependent fashion during while emitting code for a
933 function call or return (usually, by putting it in a register as opposed
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]934 to memory, though some targets use it to distinguish between two different
935 kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]936
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]937 <dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner0747baa2008-01-15 04:34:22 +0000[diff] [blame]938 <dd>This indicates that the pointer parameter should really be passed by
939 value to the function. The attribute implies that a hidden copy of the
940 pointee is made between the caller and the callee, so the callee is unable
Chris Lattnerebec6782008-08-05 18:21:08 +0000[diff] [blame]941 to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner0747baa2008-01-15 04:34:22 +0000[diff] [blame]942 pointer arguments. It is generally used to pass structs and arrays by
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]943 value, but is also valid on pointers to scalars. The copy is considered to
944 belong to the caller not the callee (for example,
945 <tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]946 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattnerce459b12009-02-05 05:42:28 +0000[diff] [blame]947 values. The byval attribute also supports specifying an alignment with the
948 align attribute. This has a target-specific effect on the code generator
949 that usually indicates a desired alignment for the synthesized stack
950 slot.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]951
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]952 <dt><tt>sret</tt></dt>
Duncan Sandse26dec62008-02-18 04:19:38 +0000[diff] [blame]953 <dd>This indicates that the pointer parameter specifies the address of a
954 structure that is the return value of the function in the source program.
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]955 This pointer must be guaranteed by the caller to be valid: loads and stores
956 to the structure may be assumed by the callee to not to trap. This may only
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]957 be applied to the first parameter. This is not a valid attribute for
958 return values. </dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]959
Zhou Shengfebca342007-06-05 05:28:26 +0000[diff] [blame]960 <dt><tt>noalias</tt></dt>
Nick Lewycky02ff3082008-11-24 03:41:24 +0000[diff] [blame]961 <dd>This indicates that the pointer does not alias any global or any other
962 parameter. The caller is responsible for ensuring that this is the
Nick Lewyckyb2b32fd2008-11-24 05:00:44 +0000[diff] [blame]963 case. On a function return value, <tt>noalias</tt> additionally indicates
964 that the pointer does not alias any other pointers visible to the
Nick Lewyckyf23d0d32008-12-19 06:39:12 +0000[diff] [blame]965 caller. For further details, please see the discussion of the NoAlias
966 response in
967 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
968 analysis</a>.</dd>
969
970 <dt><tt>nocapture</tt></dt>
971 <dd>This indicates that the callee does not make any copies of the pointer
972 that outlive the callee itself. This is not a valid attribute for return
973 values.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]974
Duncan Sands50f19f52007-07-27 19:57:41 +0000[diff] [blame]975 <dt><tt>nest</tt></dt>
Duncan Sands0789b8b2008-07-08 09:27:25 +0000[diff] [blame]976 <dd>This indicates that the pointer parameter can be excised using the
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]977 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
978 attribute for return values.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]979 </dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]980
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]981</div>
982
983<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]984<div class="doc_subsection">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]985 <a name="gc">Garbage Collector Names</a>
986</div>
987
988<div class="doc_text">
989<p>Each function may specify a garbage collector name, which is simply a
990string.</p>
991
992<div class="doc_code"><pre
993>define void @f() gc "name" { ...</pre></div>
994
995<p>The compiler declares the supported values of <i>name</i>. Specifying a
996collector which will cause the compiler to alter its output in order to support
997the named garbage collection algorithm.</p>
998</div>
999
1000<!-- ======================================================================= -->
1001<div class="doc_subsection">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1002 <a name="fnattrs">Function Attributes</a>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1003</div>
1004
1005<div class="doc_text">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1006
1007<p>Function attributes are set to communicate additional information about
1008 a function. Function attributes are considered to be part of the function,
1009 not of the function type, so functions with different parameter attributes
1010 can have the same function type.</p>
1011
1012 <p>Function attributes are simple keywords that follow the type specified. If
1013 multiple attributes are needed, they are space separated. For
1014 example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1015
1016<div class="doc_code">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1017<pre>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1018define void @f() noinline { ... }
1019define void @f() alwaysinline { ... }
1020define void @f() alwaysinline optsize { ... }
1021define void @f() optsize
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1022</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1023</div>
1024
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1025<dl>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1026<dt><tt>alwaysinline</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1027<dd>This attribute indicates that the inliner should attempt to inline this
1028function into callers whenever possible, ignoring any active inlining size
1029threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1030
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1031<dt><tt>noinline</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1032<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner94b5f7d2008-10-05 17:14:59 +0000[diff] [blame]1033in any situation. This attribute may not be used together with the
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1034<tt>alwaysinline</tt> attribute.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1035
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1036<dt><tt>optsize</tt></dt>
Devang Patel66c6c652008-09-29 18:34:44 +0000[diff] [blame]1037<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1038make choices that keep the code size of this function low, and otherwise do
1039optimizations specifically to reduce code size.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1040
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1041<dt><tt>noreturn</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1042<dd>This function attribute indicates that the function never returns normally.
1043This produces undefined behavior at runtime if the function ever does
1044dynamically return.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1045
1046<dt><tt>nounwind</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1047<dd>This function attribute indicates that the function never returns with an
1048unwind or exceptional control flow. If the function does unwind, its runtime
1049behavior is undefined.</dd>
1050
1051<dt><tt>readnone</tt></dt>
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]1052<dd>This attribute indicates that the function computes its result (or the
1053exception it throws) based strictly on its arguments, without dereferencing any
1054pointer arguments or otherwise accessing any mutable state (e.g. memory, control
1055registers, etc) visible to caller functions. It does not write through any
1056pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
1057never changes any state visible to callers.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1058
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]1059<dt><tt><a name="readonly">readonly</a></tt></dt>
1060<dd>This attribute indicates that the function does not write through any
1061pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
1062or otherwise modify any state (e.g. memory, control registers, etc) visible to
1063caller functions. It may dereference pointer arguments and read state that may
1064be set in the caller. A readonly function always returns the same value (or
1065throws the same exception) when called with the same set of arguments and global
1066state.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1067
1068<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1069<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1070protector. It is in the form of a "canary"&mdash;a random value placed on the
1071stack before the local variables that's checked upon return from the function to
1072see if it has been overwritten. A heuristic is used to determine if a function
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1073needs stack protectors or not.
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1074
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1075<p>If a function that has an <tt>ssp</tt> attribute is inlined into a function
1076that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
1077have an <tt>ssp</tt> attribute.</p></dd>
1078
1079<dt><tt>sspreq</tt></dt>
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1080<dd>This attribute indicates that the function should <em>always</em> emit a
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1081stack smashing protector. This overrides the <tt><a href="#ssp">ssp</a></tt>
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1082function attribute.
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1083
1084<p>If a function that has an <tt>sspreq</tt> attribute is inlined into a
1085function that doesn't have an <tt>sspreq</tt> attribute or which has
1086an <tt>ssp</tt> attribute, then the resulting function will have
1087an <tt>sspreq</tt> attribute.</p></dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1088</dl>
1089
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1090</div>
1091
1092<!-- ======================================================================= -->
1093<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1094 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1095</div>
1096
1097<div class="doc_text">
1098<p>
1099Modules may contain "module-level inline asm" blocks, which corresponds to the
1100GCC "file scope inline asm" blocks. These blocks are internally concatenated by
1101LLVM and treated as a single unit, but may be separated in the .ll file if
1102desired. The syntax is very simple:
1103</p>
1104
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1105<div class="doc_code">
1106<pre>
1107module asm "inline asm code goes here"
1108module asm "more can go here"
1109</pre>
1110</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1111
1112<p>The strings can contain any character by escaping non-printable characters.
1113 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
1114 for the number.
1115</p>
1116
1117<p>
1118 The inline asm code is simply printed to the machine code .s file when
1119 assembly code is generated.
1120</p>
1121</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1122
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1123<!-- ======================================================================= -->
1124<div class="doc_subsection">
1125 <a name="datalayout">Data Layout</a>
1126</div>
1127
1128<div class="doc_text">
1129<p>A module may specify a target specific data layout string that specifies how
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]1130data is to be laid out in memory. The syntax for the data layout is simply:</p>
1131<pre> target datalayout = "<i>layout specification</i>"</pre>
1132<p>The <i>layout specification</i> consists of a list of specifications
1133separated by the minus sign character ('-'). Each specification starts with a
1134letter and may include other information after the letter to define some
1135aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1136<dl>
1137 <dt><tt>E</tt></dt>
1138 <dd>Specifies that the target lays out data in big-endian form. That is, the
1139 bits with the most significance have the lowest address location.</dd>
1140 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1141 <dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1142 the bits with the least significance have the lowest address location.</dd>
1143 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1144 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
1145 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
1146 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
1147 too.</dd>
1148 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1149 <dd>This specifies the alignment for an integer type of a given bit
1150 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1151 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1152 <dd>This specifies the alignment for a vector type of a given bit
1153 <i>size</i>.</dd>
1154 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1155 <dd>This specifies the alignment for a floating point type of a given bit
1156 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1157 (double).</dd>
1158 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1159 <dd>This specifies the alignment for an aggregate type of a given bit
1160 <i>size</i>.</dd>
1161</dl>
1162<p>When constructing the data layout for a given target, LLVM starts with a
1163default set of specifications which are then (possibly) overriden by the
1164specifications in the <tt>datalayout</tt> keyword. The default specifications
1165are given in this list:</p>
1166<ul>
1167 <li><tt>E</tt> - big endian</li>
1168 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1169 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1170 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1171 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1172 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1173 <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]1174 alignment of 64-bits</li>
1175 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1176 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1177 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1178 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1179 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
1180</ul>
Chris Lattnerebec6782008-08-05 18:21:08 +0000[diff] [blame]1181<p>When LLVM is determining the alignment for a given type, it uses the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1182following rules:</p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1183<ol>
1184 <li>If the type sought is an exact match for one of the specifications, that
1185 specification is used.</li>
1186 <li>If no match is found, and the type sought is an integer type, then the
1187 smallest integer type that is larger than the bitwidth of the sought type is
1188 used. If none of the specifications are larger than the bitwidth then the the
1189 largest integer type is used. For example, given the default specifications
1190 above, the i7 type will use the alignment of i8 (next largest) while both
1191 i65 and i256 will use the alignment of i64 (largest specified).</li>
1192 <li>If no match is found, and the type sought is a vector type, then the
1193 largest vector type that is smaller than the sought vector type will be used
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1194 as a fall back. This happens because &lt;128 x double&gt; can be implemented
1195 in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1196</ol>
1197</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1198
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1199<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1200<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1201<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1202
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1203<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1204
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1205<p>The LLVM type system is one of the most important features of the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1206intermediate representation. Being typed enables a number of
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1207optimizations to be performed on the intermediate representation directly,
1208without having to do
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1209extra analyses on the side before the transformation. A strong type
1210system makes it easier to read the generated code and enables novel
1211analyses and transformations that are not feasible to perform on normal
1212three address code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1213
1214</div>
1215
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1216<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1217<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1218Classifications</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1219<div class="doc_text">
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1220<p>The types fall into a few useful
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1221classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1222
1223<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1224 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1225 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1226 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1227 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1228 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1229 </tr>
1230 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1231 <td><a href="#t_floating">floating point</a></td>
1232 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1233 </tr>
1234 <tr>
1235 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1236 <td><a href="#t_integer">integer</a>,
1237 <a href="#t_floating">floating point</a>,
1238 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1239 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1240 <a href="#t_struct">structure</a>,
1241 <a href="#t_array">array</a>,
Dan Gohmanade5faa2008-05-23 22:50:26 +0000[diff] [blame]1242 <a href="#t_label">label</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1243 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1244 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1245 <tr>
1246 <td><a href="#t_primitive">primitive</a></td>
1247 <td><a href="#t_label">label</a>,
1248 <a href="#t_void">void</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1249 <a href="#t_floating">floating point</a>.</td>
1250 </tr>
1251 <tr>
1252 <td><a href="#t_derived">derived</a></td>
1253 <td><a href="#t_integer">integer</a>,
1254 <a href="#t_array">array</a>,
1255 <a href="#t_function">function</a>,
1256 <a href="#t_pointer">pointer</a>,
1257 <a href="#t_struct">structure</a>,
1258 <a href="#t_pstruct">packed structure</a>,
1259 <a href="#t_vector">vector</a>,
1260 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1261 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1262 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1263 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1264</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1265
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1266<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1267most important. Values of these types are the only ones which can be
1268produced by instructions, passed as arguments, or used as operands to
Dan Gohmanc4b49eb2008-05-23 21:53:15 +0000[diff] [blame]1269instructions.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1270</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1271
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1272<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1273<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1274
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1275<div class="doc_text">
1276<p>The primitive types are the fundamental building blocks of the LLVM
1277system.</p>
1278
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1279</div>
1280
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1281<!-- _______________________________________________________________________ -->
1282<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1283
1284<div class="doc_text">
1285 <table>
1286 <tbody>
1287 <tr><th>Type</th><th>Description</th></tr>
1288 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1289 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1290 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1291 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1292 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1293 </tbody>
1294 </table>
1295</div>
1296
1297<!-- _______________________________________________________________________ -->
1298<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1299
1300<div class="doc_text">
1301<h5>Overview:</h5>
1302<p>The void type does not represent any value and has no size.</p>
1303
1304<h5>Syntax:</h5>
1305
1306<pre>
1307 void
1308</pre>
1309</div>
1310
1311<!-- _______________________________________________________________________ -->
1312<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1313
1314<div class="doc_text">
1315<h5>Overview:</h5>
1316<p>The label type represents code labels.</p>
1317
1318<h5>Syntax:</h5>
1319
1320<pre>
1321 label
1322</pre>
1323</div>
1324
1325
1326<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1327<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1328
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1329<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1330
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1331<p>The real power in LLVM comes from the derived types in the system.
1332This is what allows a programmer to represent arrays, functions,
1333pointers, and other useful types. Note that these derived types may be
1334recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1335
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1336</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1337
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1338<!-- _______________________________________________________________________ -->
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1339<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1340
1341<div class="doc_text">
1342
1343<h5>Overview:</h5>
1344<p>The integer type is a very simple derived type that simply specifies an
1345arbitrary bit width for the integer type desired. Any bit width from 1 bit to
13462^23-1 (about 8 million) can be specified.</p>
1347
1348<h5>Syntax:</h5>
1349
1350<pre>
1351 iN
1352</pre>
1353
1354<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1355value.</p>
1356
1357<h5>Examples:</h5>
1358<table class="layout">
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]1359 <tbody>
1360 <tr>
1361 <td><tt>i1</tt></td>
1362 <td>a single-bit integer.</td>
1363 </tr><tr>
1364 <td><tt>i32</tt></td>
1365 <td>a 32-bit integer.</td>
1366 </tr><tr>
1367 <td><tt>i1942652</tt></td>
1368 <td>a really big integer of over 1 million bits.</td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1369 </tr>
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]1370 </tbody>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1371</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1372
1373<p>Note that the code generator does not yet support large integer types
1374to be used as function return types. The specific limit on how large a
1375return type the code generator can currently handle is target-dependent;
1376currently it's often 64 bits for 32-bit targets and 128 bits for 64-bit
1377targets.</p>
1378
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1379</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1380
1381<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1382<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1383
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1384<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1385
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1386<h5>Overview:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1387
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1388<p>The array type is a very simple derived type that arranges elements
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1389sequentially in memory. The array type requires a size (number of
1390elements) and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1391
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1392<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1393
1394<pre>
1395 [&lt;# elements&gt; x &lt;elementtype&gt;]
1396</pre>
1397
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1398<p>The number of elements is a constant integer value; elementtype may
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1399be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1400
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1401<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1402<table class="layout">
1403 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1404 <td class="left"><tt>[40 x i32]</tt></td>
1405 <td class="left">Array of 40 32-bit integer values.</td>
1406 </tr>
1407 <tr class="layout">
1408 <td class="left"><tt>[41 x i32]</tt></td>
1409 <td class="left">Array of 41 32-bit integer values.</td>
1410 </tr>
1411 <tr class="layout">
1412 <td class="left"><tt>[4 x i8]</tt></td>
1413 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1414 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1415</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1416<p>Here are some examples of multidimensional arrays:</p>
1417<table class="layout">
1418 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1419 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1420 <td class="left">3x4 array of 32-bit integer values.</td>
1421 </tr>
1422 <tr class="layout">
1423 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1424 <td class="left">12x10 array of single precision floating point values.</td>
1425 </tr>
1426 <tr class="layout">
1427 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1428 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1429 </tr>
1430</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1431
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1432<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1433length array. Normally, accesses past the end of an array are undefined in
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1434LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1435As a special case, however, zero length arrays are recognized to be variable
1436length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1437type "{ i32, [0 x float]}", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1438
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1439<p>Note that the code generator does not yet support large aggregate types
1440to be used as function return types. The specific limit on how large an
1441aggregate return type the code generator can currently handle is
1442target-dependent, and also dependent on the aggregate element types.</p>
1443
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1444</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1445
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1446<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1447<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1448<div class="doc_text">
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1449
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1450<h5>Overview:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1451
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1452<p>The function type can be thought of as a function signature. It
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1453consists of a return type and a list of formal parameter types. The
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1454return type of a function type is a scalar type, a void type, or a struct type.
Devang Patel7a3ad1a2008-03-24 20:52:42 +0000[diff] [blame]1455If the return type is a struct type then all struct elements must be of first
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1456class types, and the struct must have at least one element.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1457
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1458<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1459
1460<pre>
1461 &lt;returntype list&gt; (&lt;parameter list&gt;)
1462</pre>
1463
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1464<p>...where '<tt>&lt;parameter list&gt;</tt>' is a comma-separated list of type
Misha Brukmanc24b7582004-08-12 20:16:08 +0000[diff] [blame]1465specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1466which indicates that the function takes a variable number of arguments.
1467Variable argument functions can access their arguments with the <a
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1468 href="#int_varargs">variable argument handling intrinsic</a> functions.
1469'<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1470<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1471
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1472<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1473<table class="layout">
1474 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1475 <td class="left"><tt>i32 (i32)</tt></td>
1476 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1477 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1478 </tr><tr class="layout">
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]1479 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1480 </tt></td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1481 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1482 an <tt>i16</tt> that should be sign extended and a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1483 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1484 <tt>float</tt>.
1485 </td>
1486 </tr><tr class="layout">
1487 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1488 <td class="left">A vararg function that takes at least one
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1489 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1490 which returns an integer. This is the signature for <tt>printf</tt> in
1491 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1492 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1493 </tr><tr class="layout">
1494 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukmanb0a57aa2008-11-27 06:41:20 +0000[diff] [blame]1495 <td class="left">A function taking an <tt>i32</tt>, returning two
1496 <tt>i32</tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1497 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1498 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1499</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1500
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1501</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1502<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1503<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1504<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1505<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1506<p>The structure type is used to represent a collection of data members
1507together in memory. The packing of the field types is defined to match
1508the ABI of the underlying processor. The elements of a structure may
1509be any type that has a size.</p>
1510<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1511and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1512field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1513instruction.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1514<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1515<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1516<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1517<table class="layout">
1518 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1519 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1520 <td class="left">A triple of three <tt>i32</tt> values</td>
1521 </tr><tr class="layout">
1522 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1523 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1524 second element is a <a href="#t_pointer">pointer</a> to a
1525 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1526 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1527 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1528</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1529
1530<p>Note that the code generator does not yet support large aggregate types
1531to be used as function return types. The specific limit on how large an
1532aggregate return type the code generator can currently handle is
1533target-dependent, and also dependent on the aggregate element types.</p>
1534
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1535</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1536
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1537<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1538<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1539</div>
1540<div class="doc_text">
1541<h5>Overview:</h5>
1542<p>The packed structure type is used to represent a collection of data members
1543together in memory. There is no padding between fields. Further, the alignment
1544of a packed structure is 1 byte. The elements of a packed structure may
1545be any type that has a size.</p>
1546<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1547and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1548field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1549instruction.</p>
1550<h5>Syntax:</h5>
1551<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1552<h5>Examples:</h5>
1553<table class="layout">
1554 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1555 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1556 <td class="left">A triple of three <tt>i32</tt> values</td>
1557 </tr><tr class="layout">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1558 <td class="left">
1559<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1560 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1561 second element is a <a href="#t_pointer">pointer</a> to a
1562 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1563 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1564 </tr>
1565</table>
1566</div>
1567
1568<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1569<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1570<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1571<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1572<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]1573reference to another object, which must live in memory. Pointer types may have
1574an optional address space attribute defining the target-specific numbered
1575address space where the pointed-to object resides. The default address space is
1576zero.</p>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1577
1578<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does
Chris Lattnere220e8c2009-02-08 22:21:28 +0000[diff] [blame]1579it permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1580
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1581<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1582<pre> &lt;type&gt; *<br></pre>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1583<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1584<table class="layout">
1585 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]1586 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1587 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1588 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1589 </tr>
1590 <tr class="layout">
1591 <td class="left"><tt>i32 (i32 *) *</tt></td>
1592 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1593 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1594 <tt>i32</tt>.</td>
1595 </tr>
1596 <tr class="layout">
1597 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1598 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1599 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1600 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1601</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1602</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1603
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1604<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1605<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1606<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1607
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1608<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1609
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1610<p>A vector type is a simple derived type that represents a vector
1611of elements. Vector types are used when multiple primitive data
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1612are operated in parallel using a single instruction (SIMD).
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1613A vector type requires a size (number of
Chris Lattnerb8d172f2005-11-10 01:44:22 +0000[diff] [blame]1614elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1615of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1616considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1617
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1618<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1619
1620<pre>
1621 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1622</pre>
1623
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1624<p>The number of elements is a constant integer value; elementtype may
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1625be any integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1626
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1627<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1628
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1629<table class="layout">
1630 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1631 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1632 <td class="left">Vector of 4 32-bit integer values.</td>
1633 </tr>
1634 <tr class="layout">
1635 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1636 <td class="left">Vector of 8 32-bit floating-point values.</td>
1637 </tr>
1638 <tr class="layout">
1639 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1640 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1641 </tr>
1642</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1643
1644<p>Note that the code generator does not yet support large vector types
1645to be used as function return types. The specific limit on how large a
1646vector return type codegen can currently handle is target-dependent;
1647currently it's often a few times longer than a hardware vector register.</p>
1648
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1649</div>
1650
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1651<!-- _______________________________________________________________________ -->
1652<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1653<div class="doc_text">
1654
1655<h5>Overview:</h5>
1656
1657<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksen8ac04ff2007-10-14 00:34:53 +0000[diff] [blame]1658corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1659In LLVM, opaque types can eventually be resolved to any type (not just a
1660structure type).</p>
1661
1662<h5>Syntax:</h5>
1663
1664<pre>
1665 opaque
1666</pre>
1667
1668<h5>Examples:</h5>
1669
1670<table class="layout">
1671 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1672 <td class="left"><tt>opaque</tt></td>
1673 <td class="left">An opaque type.</td>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1674 </tr>
1675</table>
1676</div>
1677
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1678<!-- ======================================================================= -->
1679<div class="doc_subsection">
1680 <a name="t_uprefs">Type Up-references</a>
1681</div>
1682
1683<div class="doc_text">
1684<h5>Overview:</h5>
1685<p>
1686An "up reference" allows you to refer to a lexically enclosing type without
1687requiring it to have a name. For instance, a structure declaration may contain a
1688pointer to any of the types it is lexically a member of. Example of up
1689references (with their equivalent as named type declarations) include:</p>
1690
1691<pre>
Chris Lattner3060f5b2009-02-09 10:00:56 +0000[diff] [blame]1692 { \2 * } %x = type { %x* }
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1693 { \2 }* %y = type { %y }*
1694 \1* %z = type %z*
1695</pre>
1696
1697<p>
1698An up reference is needed by the asmprinter for printing out cyclic types when
1699there is no declared name for a type in the cycle. Because the asmprinter does
1700not want to print out an infinite type string, it needs a syntax to handle
1701recursive types that have no names (all names are optional in llvm IR).
1702</p>
1703
1704<h5>Syntax:</h5>
1705<pre>
1706 \&lt;level&gt;
1707</pre>
1708
1709<p>
1710The level is the count of the lexical type that is being referred to.
1711</p>
1712
1713<h5>Examples:</h5>
1714
1715<table class="layout">
1716 <tr class="layout">
1717 <td class="left"><tt>\1*</tt></td>
1718 <td class="left">Self-referential pointer.</td>
1719 </tr>
1720 <tr class="layout">
1721 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
1722 <td class="left">Recursive structure where the upref refers to the out-most
1723 structure.</td>
1724 </tr>
1725</table>
1726</div>
1727
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1728
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1729<!-- *********************************************************************** -->
1730<div class="doc_section"> <a name="constants">Constants</a> </div>
1731<!-- *********************************************************************** -->
1732
1733<div class="doc_text">
1734
1735<p>LLVM has several different basic types of constants. This section describes
1736them all and their syntax.</p>
1737
1738</div>
1739
1740<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1741<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1742
1743<div class="doc_text">
1744
1745<dl>
1746 <dt><b>Boolean constants</b></dt>
1747
1748 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1749 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1750 </dd>
1751
1752 <dt><b>Integer constants</b></dt>
1753
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1754 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1755 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1756 integer types.
1757 </dd>
1758
1759 <dt><b>Floating point constants</b></dt>
1760
1761 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1762 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]1763 notation (see below). The assembler requires the exact decimal value of
1764 a floating-point constant. For example, the assembler accepts 1.25 but
1765 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1766 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1767
1768 <dt><b>Null pointer constants</b></dt>
1769
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1770 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1771 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1772
1773</dl>
1774
Dale Johannesenbd5e5a82009-02-11 22:14:51 +0000[diff] [blame]1775<p>The one non-intuitive notation for constants is the hexadecimal form
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1776of floating point constants. For example, the form '<tt>double
17770x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
17784.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1779(and the only time that they are generated by the disassembler) is when a
1780floating point constant must be emitted but it cannot be represented as a
Dale Johannesenbd5e5a82009-02-11 22:14:51 +0000[diff] [blame]1781decimal floating point number in a reasonable number of digits. For example,
1782NaN's, infinities, and other
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1783special values are represented in their IEEE hexadecimal format so that
1784assembly and disassembly do not cause any bits to change in the constants.</p>
Dale Johannesenbd5e5a82009-02-11 22:14:51 +0000[diff] [blame]1785<p>When using the hexadecimal form, constants of types float and double are
1786represented using the 16-digit form shown above (which matches the IEEE754
1787representation for double); float values must, however, be exactly representable
1788as IEE754 single precision.
1789Hexadecimal format is always used for long
1790double, and there are three forms of long double. The 80-bit
1791format used by x86 is represented as <tt>0xK</tt>
1792followed by 20 hexadecimal digits.
1793The 128-bit format used by PowerPC (two adjacent doubles) is represented
1794by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit
1795format is represented
1796by <tt>0xL</tt> followed by 32 hexadecimal digits; no currently supported
1797target uses this format. Long doubles will only work if they match
1798the long double format on your target. All hexadecimal formats are big-endian
1799(sign bit at the left).</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1800</div>
1801
1802<!-- ======================================================================= -->
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]1803<div class="doc_subsection">
1804<a name="aggregateconstants"> <!-- old anchor -->
1805<a name="complexconstants">Complex Constants</a></a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1806</div>
1807
1808<div class="doc_text">
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]1809<p>Complex constants are a (potentially recursive) combination of simple
1810constants and smaller complex constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1811
1812<dl>
1813 <dt><b>Structure constants</b></dt>
1814
1815 <dd>Structure constants are represented with notation similar to structure
1816 type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner64910ee2007-12-25 20:34:52 +0000[diff] [blame]1817 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1818 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>". Structure constants
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]1819 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1820 types of elements must match those specified by the type.
1821 </dd>
1822
1823 <dt><b>Array constants</b></dt>
1824
1825 <dd>Array constants are represented with notation similar to array type
1826 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1827 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1828 constants must have <a href="#t_array">array type</a>, and the number and
1829 types of elements must match those specified by the type.
1830 </dd>
1831
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1832 <dt><b>Vector constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1833
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1834 <dd>Vector constants are represented with notation similar to vector type
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1835 definitions (a comma separated list of elements, surrounded by
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1836 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32 42,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1837 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1838 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1839 match those specified by the type.
1840 </dd>
1841
1842 <dt><b>Zero initialization</b></dt>
1843
1844 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1845 value to zero of <em>any</em> type, including scalar and aggregate types.
1846 This is often used to avoid having to print large zero initializers (e.g. for
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1847 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1848 initializers.
1849 </dd>
1850</dl>
1851
1852</div>
1853
1854<!-- ======================================================================= -->
1855<div class="doc_subsection">
1856 <a name="globalconstants">Global Variable and Function Addresses</a>
1857</div>
1858
1859<div class="doc_text">
1860
1861<p>The addresses of <a href="#globalvars">global variables</a> and <a
1862href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1863constants. These constants are explicitly referenced when the <a
1864href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1865href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1866file:</p>
1867
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1868<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1869<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]1870@X = global i32 17
1871@Y = global i32 42
1872@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1873</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1874</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1875
1876</div>
1877
1878<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1879<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1880<div class="doc_text">
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1881 <p>The string '<tt>undef</tt>' is recognized as a type-less constant that has
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1882 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1883 a constant is permitted.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1884
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1885 <p>Undefined values indicate to the compiler that the program is well defined
1886 no matter what value is used, giving the compiler more freedom to optimize.
1887 </p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1888</div>
1889
1890<!-- ======================================================================= -->
1891<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1892</div>
1893
1894<div class="doc_text">
1895
1896<p>Constant expressions are used to allow expressions involving other constants
1897to be used as constants. Constant expressions may be of any <a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1898href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1899that does not have side effects (e.g. load and call are not supported). The
1900following is the syntax for constant expressions:</p>
1901
1902<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1903 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1904 <dd>Truncate a constant to another type. The bit size of CST must be larger
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1905 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1906
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1907 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1908 <dd>Zero extend a constant to another type. The bit size of CST must be
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1909 smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1910
1911 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1912 <dd>Sign extend a constant to another type. The bit size of CST must be
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1913 smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1914
1915 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1916 <dd>Truncate a floating point constant to another floating point type. The
1917 size of CST must be larger than the size of TYPE. Both types must be
1918 floating point.</dd>
1919
1920 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1921 <dd>Floating point extend a constant to another type. The size of CST must be
1922 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1923
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]1924 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1925 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1926 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1927 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1928 of the same number of elements. If the value won't fit in the integer type,
1929 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1930
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1931 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1932 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1933 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1934 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1935 of the same number of elements. If the value won't fit in the integer type,
1936 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1937
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1938 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1939 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1940 constant. TYPE must be a scalar or vector floating point type. CST must be of
1941 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1942 of the same number of elements. If the value won't fit in the floating point
1943 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1944
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1945 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1946 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1947 constant. TYPE must be a scalar or vector floating point type. CST must be of
1948 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1949 of the same number of elements. If the value won't fit in the floating point
1950 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1951
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1952 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1953 <dd>Convert a pointer typed constant to the corresponding integer constant
1954 TYPE must be an integer type. CST must be of pointer type. The CST value is
1955 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1956
1957 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1958 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1959 pointer type. CST must be of integer type. The CST value is zero extended,
1960 truncated, or unchanged to make it fit in a pointer size. This one is
1961 <i>really</i> dangerous!</dd>
1962
1963 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner03bbad62009-02-28 18:27:03 +0000[diff] [blame]1964 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
1965 are the same as those for the <a href="#i_bitcast">bitcast
1966 instruction</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1967
1968 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1969
1970 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1971 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1972 instruction, the index list may have zero or more indexes, which are required
1973 to make sense for the type of "CSTPTR".</dd>
1974
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1975 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1976
1977 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1978 constants.</dd>
1979
1980 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1981 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1982
1983 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1984 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1985
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]1986 <dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
1987 <dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
1988
1989 <dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
1990 <dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
1991
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1992 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1993
1994 <dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1995 operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1996
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1997 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1998
1999 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2000 operation</a> on constants.</dd>
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]2001
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2002
2003 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
2004
2005 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2006 operation</a> on constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2007
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2008 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
2009
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]2010 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2011 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2012 binary</a> operations. The constraints on operands are the same as those for
2013 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2014 values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2015</dl>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2016</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]2017
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2018<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2019<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
2020<!-- *********************************************************************** -->
2021
2022<!-- ======================================================================= -->
2023<div class="doc_subsection">
2024<a name="inlineasm">Inline Assembler Expressions</a>
2025</div>
2026
2027<div class="doc_text">
2028
2029<p>
2030LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
2031Module-Level Inline Assembly</a>) through the use of a special value. This
2032value represents the inline assembler as a string (containing the instructions
2033to emit), a list of operand constraints (stored as a string), and a flag that
2034indicates whether or not the inline asm expression has side effects. An example
2035inline assembler expression is:
2036</p>
2037
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2038<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2039<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2040i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2041</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2042</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2043
2044<p>
2045Inline assembler expressions may <b>only</b> be used as the callee operand of
2046a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
2047</p>
2048
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2049<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2050<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2051%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]2052</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2053</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2054
2055<p>
2056Inline asms with side effects not visible in the constraint list must be marked
2057as having side effects. This is done through the use of the
2058'<tt>sideeffect</tt>' keyword, like so:
2059</p>
2060
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2061<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2062<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2063call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2064</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2065</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2066
2067<p>TODO: The format of the asm and constraints string still need to be
2068documented here. Constraints on what can be done (e.g. duplication, moving, etc
Chris Lattner4f993352008-10-04 18:36:02 +0000[diff] [blame]2069need to be documented). This is probably best done by reference to another
2070document that covers inline asm from a holistic perspective.
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2071</p>
2072
2073</div>
2074
2075<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2076<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
2077<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2078
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2079<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2080
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2081<p>The LLVM instruction set consists of several different
2082classifications of instructions: <a href="#terminators">terminator
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2083instructions</a>, <a href="#binaryops">binary instructions</a>,
2084<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2085 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
2086instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2087
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2088</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2089
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2090<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2091<div class="doc_subsection"> <a name="terminators">Terminator
2092Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2093
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2094<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2095
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2096<p>As mentioned <a href="#functionstructure">previously</a>, every
2097basic block in a program ends with a "Terminator" instruction, which
2098indicates which block should be executed after the current block is
2099finished. These terminator instructions typically yield a '<tt>void</tt>'
2100value: they produce control flow, not values (the one exception being
2101the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2102<p>There are six different terminator instructions: the '<a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2103 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
2104instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2105the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
2106 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
2107 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2108
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2109</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2110
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2111<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2112<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
2113Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2114<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2115<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2116<pre>
2117 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]2118 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2119</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2120
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2121<h5>Overview:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2122
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2123<p>The '<tt>ret</tt>' instruction is used to return control flow (and
2124optionally a value) from a function back to the caller.</p>
John Criswell4457dc92004-04-09 16:48:45 +0000[diff] [blame]2125<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2126returns a value and then causes control flow, and one that just causes
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2127control flow to occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2128
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2129<h5>Arguments:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2130
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2131<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
2132the return value. The type of the return value must be a
2133'<a href="#t_firstclass">first class</a>' type.</p>
2134
2135<p>A function is not <a href="#wellformed">well formed</a> if
2136it it has a non-void return type and contains a '<tt>ret</tt>'
2137instruction with no return value or a return value with a type that
2138does not match its type, or if it has a void return type and contains
2139a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2140
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2141<h5>Semantics:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2142
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2143<p>When the '<tt>ret</tt>' instruction is executed, control flow
2144returns back to the calling function's context. If the caller is a "<a
John Criswellfa081872004-06-25 15:16:57 +0000[diff] [blame]2145 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2146the instruction after the call. If the caller was an "<a
2147 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2148at the beginning of the "normal" destination block. If the instruction
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2149returns a value, that value shall set the call or invoke instruction's
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]2150return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2151
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2152<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2153
2154<pre>
2155 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2156 ret void <i>; Return from a void function</i>
Bill Wendling0a4bbbf2009-02-28 22:12:54 +0000[diff] [blame]2157 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]2158</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2159
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]2160<p>Note that the code generator does not yet fully support large
2161 return values. The specific sizes that are currently supported are
2162 dependent on the target. For integers, on 32-bit targets the limit
2163 is often 64 bits, and on 64-bit targets the limit is often 128 bits.
2164 For aggregate types, the current limits are dependent on the element
2165 types; for example targets are often limited to 2 total integer
2166 elements and 2 total floating-point elements.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2167
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2168</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2169<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2170<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2171<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2172<h5>Syntax:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2173<pre> br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;<br> br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2174</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2175<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2176<p>The '<tt>br</tt>' instruction is used to cause control flow to
2177transfer to a different basic block in the current function. There are
2178two forms of this instruction, corresponding to a conditional branch
2179and an unconditional branch.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2180<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2181<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2182single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]2183unconditional form of the '<tt>br</tt>' instruction takes a single
2184'<tt>label</tt>' value as a target.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2185<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2186<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2187argument is evaluated. If the value is <tt>true</tt>, control flows
2188to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2189control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2190<h5>Example:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2191<pre>Test:<br> %cond = <a href="#i_icmp">icmp</a> eq, i32 %a, %b<br> br i1 %cond, label %IfEqual, label %IfUnequal<br>IfEqual:<br> <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2192 href="#i_ret">ret</a> i32 1<br>IfUnequal:<br> <a href="#i_ret">ret</a> i32 0<br></pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2193</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2194<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2195<div class="doc_subsubsection">
2196 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2197</div>
2198
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2199<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2200<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2201
2202<pre>
2203 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2204</pre>
2205
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2206<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2207
2208<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
2209several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2210instruction, allowing a branch to occur to one of many possible
2211destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2212
2213
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2214<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2215
2216<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
2217comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
2218an array of pairs of comparison value constants and '<tt>label</tt>'s. The
2219table is not allowed to contain duplicate constant entries.</p>
2220
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2221<h5>Semantics:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2222
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2223<p>The <tt>switch</tt> instruction specifies a table of values and
2224destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]2225table is searched for the given value. If the value is found, control flow is
2226transfered to the corresponding destination; otherwise, control flow is
2227transfered to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2228
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2229<h5>Implementation:</h5>
2230
2231<p>Depending on properties of the target machine and the particular
2232<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]2233ways. For example, it could be generated as a series of chained conditional
2234branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2235
2236<h5>Example:</h5>
2237
2238<pre>
2239 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2240 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2241 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2242
2243 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2244 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2245
2246 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2247 switch i32 %val, label %otherwise [ i32 0, label %onzero
2248 i32 1, label %onone
2249 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2250</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2251</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2252
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2253<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2254<div class="doc_subsubsection">
2255 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2256</div>
2257
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2258<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2259
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2260<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2261
2262<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2263 &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]2264 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2265</pre>
2266
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2267<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2268
2269<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
2270function, with the possibility of control flow transfer to either the
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2271'<tt>normal</tt>' label or the
2272'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2273"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
2274"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2275href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]2276continued at the dynamically nearest "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2277
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2278<h5>Arguments:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2279
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2280<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2281
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2282<ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2283 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]2284 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2285 convention</a> the call should use. If none is specified, the call defaults
2286 to using C calling conventions.
2287 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2288
2289 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
2290 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
2291 and '<tt>inreg</tt>' attributes are valid here.</li>
2292
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2293 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
2294 function value being invoked. In most cases, this is a direct function
2295 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
2296 an arbitrary pointer to function value.
2297 </li>
2298
2299 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
2300 function to be invoked. </li>
2301
2302 <li>'<tt>function args</tt>': argument list whose types match the function
2303 signature argument types. If the function signature indicates the function
2304 accepts a variable number of arguments, the extra arguments can be
2305 specified. </li>
2306
2307 <li>'<tt>normal label</tt>': the label reached when the called function
2308 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
2309
2310 <li>'<tt>exception label</tt>': the label reached when a callee returns with
2311 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
2312
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2313 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2314 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2315 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2316</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2317
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2318<h5>Semantics:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2319
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2320<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2321href="#i_call">call</a></tt>' instruction in most regards. The primary
2322difference is that it establishes an association with a label, which is used by
2323the runtime library to unwind the stack.</p>
2324
2325<p>This instruction is used in languages with destructors to ensure that proper
2326cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2327exception. Additionally, this is important for implementation of
2328'<tt>catch</tt>' clauses in high-level languages that support them.</p>
2329
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2330<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2331<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2332 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2333 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2334 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2335 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2336</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2337</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2338
2339
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2340<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2341
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2342<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2343Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2344
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2345<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2346
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2347<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2348<pre>
2349 unwind
2350</pre>
2351
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2352<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2353
2354<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
2355at the first callee in the dynamic call stack which used an <a
2356href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
2357primarily used to implement exception handling.</p>
2358
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2359<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2360
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]2361<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2362immediately halt. The dynamic call stack is then searched for the first <a
2363href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
2364execution continues at the "exceptional" destination block specified by the
2365<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
2366dynamic call chain, undefined behavior results.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2367</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2368
2369<!-- _______________________________________________________________________ -->
2370
2371<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2372Instruction</a> </div>
2373
2374<div class="doc_text">
2375
2376<h5>Syntax:</h5>
2377<pre>
2378 unreachable
2379</pre>
2380
2381<h5>Overview:</h5>
2382
2383<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
2384instruction is used to inform the optimizer that a particular portion of the
2385code is not reachable. This can be used to indicate that the code after a
2386no-return function cannot be reached, and other facts.</p>
2387
2388<h5>Semantics:</h5>
2389
2390<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
2391</div>
2392
2393
2394
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2395<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2396<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2397<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2398<p>Binary operators are used to do most of the computation in a
Chris Lattner5a158142008-04-01 18:47:32 +0000[diff] [blame]2399program. They require two operands of the same type, execute an operation on them, and
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2400produce a single value. The operands might represent
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2401multiple data, as is the case with the <a href="#t_vector">vector</a> data type.
Chris Lattner5a158142008-04-01 18:47:32 +0000[diff] [blame]2402The result value has the same type as its operands.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2403<p>There are several different binary operators:</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2404</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2405<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2406<div class="doc_subsubsection">
2407 <a name="i_add">'<tt>add</tt>' Instruction</a>
2408</div>
2409
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2410<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2411
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2412<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2413
2414<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2415 &lt;result&gt; = 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]2416</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2417
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2418<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2419
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2420<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2421
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2422<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2423
2424<p>The two arguments to the '<tt>add</tt>' instruction must be <a
2425 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
2426 <a href="#t_vector">vector</a> values. Both arguments must have identical
2427 types.</p>
2428
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2429<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2430
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2431<p>The value produced is the integer or floating point sum of the two
2432operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2433
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2434<p>If an integer sum has unsigned overflow, the result returned is the
2435mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2436the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2437
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2438<p>Because LLVM integers use a two's complement representation, this
2439instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2440
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2441<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2442
2443<pre>
2444 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2445</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2446</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2447<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2448<div class="doc_subsubsection">
2449 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2450</div>
2451
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2452<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2453
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2454<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2455
2456<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2457 &lt;result&gt; = 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]2458</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2459
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2460<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2461
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2462<p>The '<tt>sub</tt>' instruction returns the difference of its two
2463operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2464
2465<p>Note that the '<tt>sub</tt>' instruction is used to represent the
2466'<tt>neg</tt>' instruction present in most other intermediate
2467representations.</p>
2468
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2469<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2470
2471<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
2472 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2473 or <a href="#t_vector">vector</a> values. Both arguments must have identical
2474 types.</p>
2475
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2476<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2477
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2478<p>The value produced is the integer or floating point difference of
2479the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2480
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2481<p>If an integer difference has unsigned overflow, the result returned is the
2482mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2483the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2484
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2485<p>Because LLVM integers use a two's complement representation, this
2486instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2487
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2488<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2489<pre>
2490 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2491 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2492</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2493</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2494
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2495<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2496<div class="doc_subsubsection">
2497 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2498</div>
2499
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2500<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2501
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2502<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2503<pre> &lt;result&gt; = 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]2504</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2505<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2506<p>The '<tt>mul</tt>' instruction returns the product of its two
2507operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2508
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2509<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2510
2511<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
2512href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2513or <a href="#t_vector">vector</a> values. Both arguments must have identical
2514types.</p>
2515
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2516<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2517
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2518<p>The value produced is the integer or floating point product of the
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2519two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2520
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2521<p>If the result of an integer multiplication has unsigned overflow,
2522the result returned is the mathematical result modulo
25232<sup>n</sup>, where n is the bit width of the result.</p>
2524<p>Because LLVM integers use a two's complement representation, and the
2525result is the same width as the operands, this instruction returns the
2526correct result for both signed and unsigned integers. If a full product
2527(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
2528should be sign-extended or zero-extended as appropriate to the
2529width of the full product.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2530<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2531<pre> &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2532</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2533</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2534
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2535<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2536<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2537</a></div>
2538<div class="doc_text">
2539<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2540<pre> &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]2541</pre>
2542<h5>Overview:</h5>
2543<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2544operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2545
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2546<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2547
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2548<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2549<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2550values. Both arguments must have identical types.</p>
2551
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2552<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2553
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2554<p>The value produced is the unsigned integer quotient of the two operands.</p>
2555<p>Note that unsigned integer division and signed integer division are distinct
2556operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2557<p>Division by zero leads to undefined behavior.</p>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2558<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2559<pre> &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2560</pre>
2561</div>
2562<!-- _______________________________________________________________________ -->
2563<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2564</a> </div>
2565<div class="doc_text">
2566<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2567<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2568 &lt;result&gt; = 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]2569</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2570
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2571<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2572
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2573<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2574operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2575
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2576<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2577
2578<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2579<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2580values. Both arguments must have identical types.</p>
2581
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2582<h5>Semantics:</h5>
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2583<p>The value produced is the signed integer quotient of the two operands rounded towards zero.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2584<p>Note that signed integer division and unsigned integer division are distinct
2585operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2586<p>Division by zero leads to undefined behavior. Overflow also leads to
2587undefined behavior; this is a rare case, but can occur, for example,
2588by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2589<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2590<pre> &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2591</pre>
2592</div>
2593<!-- _______________________________________________________________________ -->
2594<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2595Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2596<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2597<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2598<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2599 &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]2600</pre>
2601<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2602
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2603<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2604operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2605
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2606<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2607
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2608<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2609<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2610of floating point values. Both arguments must have identical types.</p>
2611
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2612<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2613
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2614<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2615
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2616<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2617
2618<pre>
2619 &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]2620</pre>
2621</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2622
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2623<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2624<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2625</div>
2626<div class="doc_text">
2627<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2628<pre> &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]2629</pre>
2630<h5>Overview:</h5>
2631<p>The '<tt>urem</tt>' instruction returns the remainder from the
2632unsigned division of its two arguments.</p>
2633<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2634<p>The two arguments to the '<tt>urem</tt>' instruction must be
2635<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2636values. Both arguments must have identical types.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2637<h5>Semantics:</h5>
2638<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2639This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2640<p>Note that unsigned integer remainder and signed integer remainder are
2641distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
2642<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2643<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2644<pre> &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2645</pre>
2646
2647</div>
2648<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2649<div class="doc_subsubsection">
2650 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
2651</div>
2652
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2653<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2654
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2655<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2656
2657<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2658 &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]2659</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2660
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2661<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2662
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2663<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2664signed division of its two operands. This instruction can also take
2665<a href="#t_vector">vector</a> versions of the values in which case
2666the elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]2667
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2668<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2669
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2670<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2671<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2672values. Both arguments must have identical types.</p>
2673
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2674<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2675
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2676<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2677has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
2678operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2679a value. For more information about the difference, see <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2680 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2681Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencer64f5c6c2007-03-24 22:40:44 +0000[diff] [blame]2682please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2683Wikipedia: modulo operation</a>.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2684<p>Note that signed integer remainder and unsigned integer remainder are
2685distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
2686<p>Taking the remainder of a division by zero leads to undefined behavior.
2687Overflow also leads to undefined behavior; this is a rare case, but can occur,
2688for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
2689(The remainder doesn't actually overflow, but this rule lets srem be
2690implemented using instructions that return both the result of the division
2691and the remainder.)</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2692<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2693<pre> &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2694</pre>
2695
2696</div>
2697<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2698<div class="doc_subsubsection">
2699 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
2700
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2701<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2702
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2703<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2704<pre> &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]2705</pre>
2706<h5>Overview:</h5>
2707<p>The '<tt>frem</tt>' instruction returns the remainder from the
2708division of its two operands.</p>
2709<h5>Arguments:</h5>
2710<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2711<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2712of floating point values. Both arguments must have identical types.</p>
2713
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2714<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2715
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2716<p>This instruction returns the <i>remainder</i> of a division.
2717The remainder has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2718
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2719<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2720
2721<pre>
2722 &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]2723</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2724</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]2725
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2726<!-- ======================================================================= -->
2727<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2728Operations</a> </div>
2729<div class="doc_text">
2730<p>Bitwise binary operators are used to do various forms of
2731bit-twiddling in a program. They are generally very efficient
2732instructions and can commonly be strength reduced from other
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2733instructions. They require two operands of the same type, execute an operation on them,
2734and produce a single value. The resulting value is the same type as its operands.</p>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2735</div>
2736
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2737<!-- _______________________________________________________________________ -->
2738<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2739Instruction</a> </div>
2740<div class="doc_text">
2741<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2742<pre> &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]2743</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2744
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2745<h5>Overview:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2746
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2747<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2748the left a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2749
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2750<h5>Arguments:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2751
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2752<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2753 href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2754type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2755
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2756<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2757
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2758<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
2759where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
Mon P Wang01f8d092008-12-10 08:55:09 +0000[diff] [blame]2760equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
2761If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
2762corresponding shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2763
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2764<h5>Example:</h5><pre>
2765 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2766 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2767 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2768 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]2769 &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]2770</pre>
2771</div>
2772<!-- _______________________________________________________________________ -->
2773<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2774Instruction</a> </div>
2775<div class="doc_text">
2776<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2777<pre> &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]2778</pre>
2779
2780<h5>Overview:</h5>
2781<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2782operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2783
2784<h5>Arguments:</h5>
2785<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2786<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2787type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2788
2789<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2790
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2791<p>This instruction always performs a logical shift right operation. The most
2792significant bits of the result will be filled with zero bits after the
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2793shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
Mon P Wang01f8d092008-12-10 08:55:09 +0000[diff] [blame]2794the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
2795vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
2796amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2797
2798<h5>Example:</h5>
2799<pre>
2800 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2801 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2802 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2803 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2804 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]2805 &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]2806</pre>
2807</div>
2808
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2809<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2810<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2811Instruction</a> </div>
2812<div class="doc_text">
2813
2814<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2815<pre> &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]2816</pre>
2817
2818<h5>Overview:</h5>
2819<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2820operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2821
2822<h5>Arguments:</h5>
2823<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2824<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2825type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2826
2827<h5>Semantics:</h5>
2828<p>This instruction always performs an arithmetic shift right operation,
2829The most significant bits of the result will be filled with the sign bit
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2830of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
Mon P Wang01f8d092008-12-10 08:55:09 +0000[diff] [blame]2831larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
2832arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
2833corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2834
2835<h5>Example:</h5>
2836<pre>
2837 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2838 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2839 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2840 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2841 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]2842 &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]2843</pre>
2844</div>
2845
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2846<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2847<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2848Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2849
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2850<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2851
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2852<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2853
2854<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2855 &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]2856</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2857
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2858<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2859
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2860<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2861its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2862
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2863<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2864
2865<p>The two arguments to the '<tt>and</tt>' instruction must be
2866<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2867values. Both arguments must have identical types.</p>
2868
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2869<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2870<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2871<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2872<div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2873<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2874 <tbody>
2875 <tr>
2876 <td>In0</td>
2877 <td>In1</td>
2878 <td>Out</td>
2879 </tr>
2880 <tr>
2881 <td>0</td>
2882 <td>0</td>
2883 <td>0</td>
2884 </tr>
2885 <tr>
2886 <td>0</td>
2887 <td>1</td>
2888 <td>0</td>
2889 </tr>
2890 <tr>
2891 <td>1</td>
2892 <td>0</td>
2893 <td>0</td>
2894 </tr>
2895 <tr>
2896 <td>1</td>
2897 <td>1</td>
2898 <td>1</td>
2899 </tr>
2900 </tbody>
2901</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2902</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2903<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2904<pre>
2905 &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]2906 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2907 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2908</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2909</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2910<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2911<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2912<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2913<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2914<pre> &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2915</pre>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2916<h5>Overview:</h5>
2917<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2918or of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2919<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2920
2921<p>The two arguments to the '<tt>or</tt>' instruction must be
2922<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2923values. Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2924<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2925<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2926<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2927<div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2928<table border="1" cellspacing="0" cellpadding="4">
2929 <tbody>
2930 <tr>
2931 <td>In0</td>
2932 <td>In1</td>
2933 <td>Out</td>
2934 </tr>
2935 <tr>
2936 <td>0</td>
2937 <td>0</td>
2938 <td>0</td>
2939 </tr>
2940 <tr>
2941 <td>0</td>
2942 <td>1</td>
2943 <td>1</td>
2944 </tr>
2945 <tr>
2946 <td>1</td>
2947 <td>0</td>
2948 <td>1</td>
2949 </tr>
2950 <tr>
2951 <td>1</td>
2952 <td>1</td>
2953 <td>1</td>
2954 </tr>
2955 </tbody>
2956</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2957</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2958<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2959<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2960 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2961 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2962</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2963</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2964<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2965<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2966Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2967<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2968<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2969<pre> &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]2970</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2971<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2972<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2973or of its two operands. The <tt>xor</tt> is used to implement the
2974"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2975<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2976<p>The two arguments to the '<tt>xor</tt>' instruction must be
2977<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2978values. Both arguments must have identical types.</p>
2979
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2980<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2981
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2982<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2983<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2984<div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2985<table border="1" cellspacing="0" cellpadding="4">
2986 <tbody>
2987 <tr>
2988 <td>In0</td>
2989 <td>In1</td>
2990 <td>Out</td>
2991 </tr>
2992 <tr>
2993 <td>0</td>
2994 <td>0</td>
2995 <td>0</td>
2996 </tr>
2997 <tr>
2998 <td>0</td>
2999 <td>1</td>
3000 <td>1</td>
3001 </tr>
3002 <tr>
3003 <td>1</td>
3004 <td>0</td>
3005 <td>1</td>
3006 </tr>
3007 <tr>
3008 <td>1</td>
3009 <td>1</td>
3010 <td>0</td>
3011 </tr>
3012 </tbody>
3013</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]3014</div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3015<p> </p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3016<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3017<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
3018 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
3019 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
3020 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3021</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3022</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3023
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3024<!-- ======================================================================= -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3025<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3026 <a name="vectorops">Vector Operations</a>
3027</div>
3028
3029<div class="doc_text">
3030
3031<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3032target-independent manner. These instructions cover the element-access and
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3033vector-specific operations needed to process vectors effectively. While LLVM
3034does directly support these vector operations, many sophisticated algorithms
3035will want to use target-specific intrinsics to take full advantage of a specific
3036target.</p>
3037
3038</div>
3039
3040<!-- _______________________________________________________________________ -->
3041<div class="doc_subsubsection">
3042 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
3043</div>
3044
3045<div class="doc_text">
3046
3047<h5>Syntax:</h5>
3048
3049<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3050 &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]3051</pre>
3052
3053<h5>Overview:</h5>
3054
3055<p>
3056The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3057element from a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3058</p>
3059
3060
3061<h5>Arguments:</h5>
3062
3063<p>
3064The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3065value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3066an index indicating the position from which to extract the element.
3067The index may be a variable.</p>
3068
3069<h5>Semantics:</h5>
3070
3071<p>
3072The result is a scalar of the same type as the element type of
3073<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
3074<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3075results are undefined.
3076</p>
3077
3078<h5>Example:</h5>
3079
3080<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3081 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3082</pre>
3083</div>
3084
3085
3086<!-- _______________________________________________________________________ -->
3087<div class="doc_subsubsection">
3088 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
3089</div>
3090
3091<div class="doc_text">
3092
3093<h5>Syntax:</h5>
3094
3095<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]3096 &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]3097</pre>
3098
3099<h5>Overview:</h5>
3100
3101<p>
3102The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3103element into a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3104</p>
3105
3106
3107<h5>Arguments:</h5>
3108
3109<p>
3110The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3111value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3112scalar value whose type must equal the element type of the first
3113operand. The third operand is an index indicating the position at
3114which to insert the value. The index may be a variable.</p>
3115
3116<h5>Semantics:</h5>
3117
3118<p>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3119The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3120element values are those of <tt>val</tt> except at position
3121<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
3122exceeds the length of <tt>val</tt>, the results are undefined.
3123</p>
3124
3125<h5>Example:</h5>
3126
3127<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3128 %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]3129</pre>
3130</div>
3131
3132<!-- _______________________________________________________________________ -->
3133<div class="doc_subsubsection">
3134 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3135</div>
3136
3137<div class="doc_text">
3138
3139<h5>Syntax:</h5>
3140
3141<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3142 &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]3143</pre>
3144
3145<h5>Overview:</h5>
3146
3147<p>
3148The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3149from two input vectors, returning a vector with the same element type as
3150the input and length that is the same as the shuffle mask.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3151</p>
3152
3153<h5>Arguments:</h5>
3154
3155<p>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3156The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
3157with types that match each other. The third argument is a shuffle mask whose
3158element type is always 'i32'. The result of the instruction is a vector whose
3159length is the same as the shuffle mask and whose element type is the same as
3160the element type of the first two operands.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3161</p>
3162
3163<p>
3164The shuffle mask operand is required to be a constant vector with either
3165constant integer or undef values.
3166</p>
3167
3168<h5>Semantics:</h5>
3169
3170<p>
3171The elements of the two input vectors are numbered from left to right across
3172both of the vectors. The shuffle mask operand specifies, for each element of
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3173the result vector, which element of the two input vectors the result element
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3174gets. The element selector may be undef (meaning "don't care") and the second
3175operand may be undef if performing a shuffle from only one vector.
3176</p>
3177
3178<h5>Example:</h5>
3179
3180<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3181 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3182 &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]3183 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
3184 &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]3185 %result = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
3186 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
3187 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
3188 &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]3189</pre>
3190</div>
3191
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]3192
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3193<!-- ======================================================================= -->
3194<div class="doc_subsection">
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3195 <a name="aggregateops">Aggregate Operations</a>
3196</div>
3197
3198<div class="doc_text">
3199
3200<p>LLVM supports several instructions for working with aggregate values.
3201</p>
3202
3203</div>
3204
3205<!-- _______________________________________________________________________ -->
3206<div class="doc_subsubsection">
3207 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3208</div>
3209
3210<div class="doc_text">
3211
3212<h5>Syntax:</h5>
3213
3214<pre>
3215 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3216</pre>
3217
3218<h5>Overview:</h5>
3219
3220<p>
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3221The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3222or array element from an aggregate value.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3223</p>
3224
3225
3226<h5>Arguments:</h5>
3227
3228<p>
3229The first operand of an '<tt>extractvalue</tt>' instruction is a
3230value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3231type. The operands are constant indices to specify which value to extract
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3232in a similar manner as indices in a
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3233'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3234</p>
3235
3236<h5>Semantics:</h5>
3237
3238<p>
3239The result is the value at the position in the aggregate specified by
3240the index operands.
3241</p>
3242
3243<h5>Example:</h5>
3244
3245<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3246 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3247</pre>
3248</div>
3249
3250
3251<!-- _______________________________________________________________________ -->
3252<div class="doc_subsubsection">
3253 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3254</div>
3255
3256<div class="doc_text">
3257
3258<h5>Syntax:</h5>
3259
3260<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3261 &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]3262</pre>
3263
3264<h5>Overview:</h5>
3265
3266<p>
3267The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3268into a struct field or array element in an aggregate.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3269</p>
3270
3271
3272<h5>Arguments:</h5>
3273
3274<p>
3275The first operand of an '<tt>insertvalue</tt>' instruction is a
3276value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
3277The second operand is a first-class value to insert.
Dan Gohmanc4b49eb2008-05-23 21:53:15 +0000[diff] [blame]3278The following operands are constant indices
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3279indicating the position at which to insert the value in a similar manner as
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3280indices in a
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3281'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3282The value to insert must have the same type as the value identified
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3283by the indices.
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3284</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3285
3286<h5>Semantics:</h5>
3287
3288<p>
3289The result is an aggregate of the same type as <tt>val</tt>. Its
3290value is that of <tt>val</tt> except that the value at the position
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3291specified by the indices is that of <tt>elt</tt>.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3292</p>
3293
3294<h5>Example:</h5>
3295
3296<pre>
Dan Gohman52bb2db2008-06-23 15:26:37 +0000[diff] [blame]3297 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3298</pre>
3299</div>
3300
3301
3302<!-- ======================================================================= -->
3303<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3304 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3305</div>
3306
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3307<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3308
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3309<p>A key design point of an SSA-based representation is how it
3310represents memory. In LLVM, no memory locations are in SSA form, which
3311makes things very simple. This section describes how to read, write,
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3312allocate, and free memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3313
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3314</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3315
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3316<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3317<div class="doc_subsubsection">
3318 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3319</div>
3320
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3321<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3322
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3323<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3324
3325<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3326 &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]3327</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3328
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3329<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3330
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3331<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]3332heap and returns a pointer to it. The object is always allocated in the generic
3333address space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3334
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3335<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3336
3337<p>The '<tt>malloc</tt>' instruction allocates
3338<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswell6e4ca612004-02-24 16:13:56 +0000[diff] [blame]3339bytes of memory from the operating system and returns a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3340appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3341number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3342If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3343be aligned to at least that boundary. If not specified, or if zero, the target can
3344choose to align the allocation on any convenient boundary.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3345
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3346<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3347
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3348<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3349
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3350<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewycky02ff3082008-11-24 03:41:24 +0000[diff] [blame]3351a pointer is returned. The result of a zero byte allocation is undefined. The
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3352result is null if there is insufficient memory available.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3353
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3354<h5>Example:</h5>
3355
3356<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3357 %array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3358
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3359 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3360 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3361 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3362 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3363 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3364</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]3365
3366<p>Note that the code generator does not yet respect the
3367 alignment value.</p>
3368
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3369</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3370
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3371<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3372<div class="doc_subsubsection">
3373 <a name="i_free">'<tt>free</tt>' Instruction</a>
3374</div>
3375
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3376<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3377
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3378<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3379
3380<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3381 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3382</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3383
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3384<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3385
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3386<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]3387memory heap to be reallocated in the future.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3388
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3389<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3390
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3391<p>'<tt>value</tt>' shall be a pointer value that points to a value
3392that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
3393instruction.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3394
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3395<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3396
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3397<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattnere0db56d2008-04-19 22:41:32 +0000[diff] [blame]3398after this instruction executes. If the pointer is null, the operation
3399is a noop.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3400
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3401<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3402
3403<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3404 %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]3405 free [4 x i8]* %array
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3406</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3407</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3408
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3409<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3410<div class="doc_subsubsection">
3411 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3412</div>
3413
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3414<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3415
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3416<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3417
3418<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3419 &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]3420</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3421
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3422<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3423
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3424<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
3425currently executing function, to be automatically released when this function
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]3426returns to its caller. The object is always allocated in the generic address
3427space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3428
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3429<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3430
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3431<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3432bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3433appropriate type to the program. If "NumElements" is specified, it is the
3434number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3435If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3436to be aligned to at least that boundary. If not specified, or if zero, the target
3437can choose to align the allocation on any convenient boundary.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3438
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3439<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3440
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3441<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3442
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3443<p>Memory is allocated; a pointer is returned. The operation is undefiend if
3444there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3445memory is automatically released when the function returns. The '<tt>alloca</tt>'
3446instruction is commonly used to represent automatic variables that must
3447have an address available. When the function returns (either with the <tt><a
John Criswelldae2e932005-05-12 16:55:34 +0000[diff] [blame]3448 href="#i_ret">ret</a></tt> or <tt><a href="#i_unwind">unwind</a></tt>
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3449instructions), the memory is reclaimed. Allocating zero bytes
3450is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3451
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3452<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3453
3454<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3455 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
3456 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3457 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
3458 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3459</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3460</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3461
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3462<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3463<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3464Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3465<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3466<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]3467<pre> &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]<br> &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]<br></pre>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3468<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3469<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3470<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3471<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]3472address from which to load. The pointer must point to a <a
Chris Lattnere53e5082004-06-03 22:57:15 +0000[diff] [blame]3473 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]3474marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3475the number or order of execution of this <tt>load</tt> with other
3476volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3477instructions. </p>
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3478<p>
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3479The optional constant "align" argument specifies the alignment of the operation
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3480(that is, the alignment of the memory address). A value of 0 or an
3481omitted "align" argument means that the operation has the preferential
3482alignment for the target. It is the responsibility of the code emitter
3483to ensure that the alignment information is correct. Overestimating
3484the alignment results in an undefined behavior. Underestimating the
3485alignment may produce less efficient code. An alignment of 1 is always
3486safe.
3487</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3488<h5>Semantics:</h5>
Duncan Sands19527c62009-03-22 11:33:16 +0000[diff] [blame^]3489<p>The location of memory pointed to is loaded. If the value being loaded
3490is of scalar type then the number of bytes read does not exceed the minimum
3491number of bytes needed to hold all bits of the type. For example, loading an
3492<tt>i24</tt> reads at most three bytes. When loading a value of a type like
3493<tt>i20</tt> with a size that is not an integral number of bytes, the result
3494is undefined if the value was not originally written using a store of the
3495same type.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3496<h5>Examples:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3497<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3498 <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3499 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
3500 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3501</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3502</div>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3503<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3504<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3505Instruction</a> </div>
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]3506<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3507<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]3508<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
3509 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]3510</pre>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3511<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3512<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3513<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3514<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3515to store and an address at which to store it. The type of the '<tt>&lt;pointer&gt;</tt>'
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3516operand must be a pointer to the <a href="#t_firstclass">first class</a> type
3517of the '<tt>&lt;value&gt;</tt>'
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]3518operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3519optimizer is not allowed to modify the number or order of execution of
3520this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
3521 href="#i_store">store</a></tt> instructions.</p>
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3522<p>
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3523The optional constant "align" argument specifies the alignment of the operation
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3524(that is, the alignment of the memory address). A value of 0 or an
3525omitted "align" argument means that the operation has the preferential
3526alignment for the target. It is the responsibility of the code emitter
3527to ensure that the alignment information is correct. Overestimating
3528the alignment results in an undefined behavior. Underestimating the
3529alignment may produce less efficient code. An alignment of 1 is always
3530safe.
3531</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3532<h5>Semantics:</h5>
3533<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
Duncan Sands19527c62009-03-22 11:33:16 +0000[diff] [blame^]3534at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.
3535If '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes
3536written does not exceed the minimum number of bytes needed to hold all
3537bits of the type. For example, storing an <tt>i24</tt> writes at most
3538three bytes. When writing a value of a type like <tt>i20</tt> with a
3539size that is not an integral number of bytes, it is unspecified what
3540happens to the extra bits that do not belong to the type, but they will
3541typically be overwritten.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3542<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3543<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]3544 store i32 3, i32* %ptr <i>; yields {void}</i>
3545 %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]3546</pre>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3547</div>
3548
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3549<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3550<div class="doc_subsubsection">
3551 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3552</div>
3553
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3554<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3555<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3556<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3557 &lt;result&gt; = getelementptr &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3558</pre>
3559
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3560<h5>Overview:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3561
3562<p>
3563The '<tt>getelementptr</tt>' instruction is used to get the address of a
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3564subelement of an aggregate data structure. It performs address calculation only
3565and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3566
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3567<h5>Arguments:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3568
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3569<p>The first argument is always a pointer, and forms the basis of the
3570calculation. The remaining arguments are indices, that indicate which of the
3571elements of the aggregate object are indexed. The interpretation of each index
3572is dependent on the type being indexed into. The first index always indexes the
3573pointer value given as the first argument, the second index indexes a value of
3574the type pointed to (not necessarily the value directly pointed to, since the
3575first index can be non-zero), etc. The first type indexed into must be a pointer
3576value, subsequent types can be arrays, vectors and structs. Note that subsequent
3577types being indexed into can never be pointers, since that would require loading
3578the pointer before continuing calculation.</p>
3579
3580<p>The type of each index argument depends on the type it is indexing into.
3581When indexing into a (packed) structure, only <tt>i32</tt> integer
3582<b>constants</b> are allowed. When indexing into an array, pointer or vector,
3583only integers of 32 or 64 bits are allowed (also non-constants). 32-bit values
3584will be sign extended to 64-bits if required.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3585
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3586<p>For example, let's consider a C code fragment and how it gets
3587compiled to LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3588
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3589<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3590<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3591struct RT {
3592 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3593 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3594 char C;
3595};
3596struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3597 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3598 double Y;
3599 struct RT Z;
3600};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3601
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3602int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3603 return &amp;s[1].Z.B[5][13];
3604}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3605</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3606</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3607
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3608<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3609
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3610<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3611<pre>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]3612%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
3613%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3614
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3615define i32* %foo(%ST* %s) {
3616entry:
3617 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3618 ret i32* %reg
3619}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3620</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3621</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3622
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3623<h5>Semantics:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3624
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3625<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3626type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3627}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3628the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3629i8 }</tt>' type, another structure. The third index indexes into the second
3630element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3631array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3632'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
3633to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3634
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3635<p>Note that it is perfectly legal to index partially through a
3636structure, returning a pointer to an inner element. Because of this,
3637the LLVM code for the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3638
3639<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3640 define i32* %foo(%ST* %s) {
3641 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3642 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3643 %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]3644 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3645 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
3646 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3647 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3648</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3649
Chris Lattner8c0e62c2009-03-09 20:55:18 +0000[diff] [blame]3650<p>Note that it is undefined to access an array out of bounds: array
3651and pointer indexes must always be within the defined bounds of the
3652array type when accessed with an instruction that dereferences the
3653pointer (e.g. a load or store instruction). The one exception for
3654this rule is zero length arrays. These arrays are defined to be
3655accessible as variable length arrays, which requires access beyond the
3656zero'th element.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3657
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3658<p>The getelementptr instruction is often confusing. For some more insight
3659into how it works, see <a href="GetElementPtr.html">the getelementptr
3660FAQ</a>.</p>
3661
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3662<h5>Example:</h5>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3663
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3664<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3665 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3666 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
3667 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3668 %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]3669 <i>; yields i8*:eptr</i>
3670 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3671</pre>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3672</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3673
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3674<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3675<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3676</div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3677<div class="doc_text">
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3678<p>The instructions in this category are the conversion instructions (casting)
3679which all take a single operand and a type. They perform various bit conversions
3680on the operand.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3681</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3682
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3683<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3684<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3685 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
3686</div>
3687<div class="doc_text">
3688
3689<h5>Syntax:</h5>
3690<pre>
3691 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3692</pre>
3693
3694<h5>Overview:</h5>
3695<p>
3696The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
3697</p>
3698
3699<h5>Arguments:</h5>
3700<p>
3701The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
3702be an <a href="#t_integer">integer</a> type, and a type that specifies the size
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3703and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3704type. The bit size of <tt>value</tt> must be larger than the bit size of
3705<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3706
3707<h5>Semantics:</h5>
3708<p>
3709The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3710and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
3711larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
3712It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3713
3714<h5>Example:</h5>
3715<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3716 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3717 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
3718 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3719</pre>
3720</div>
3721
3722<!-- _______________________________________________________________________ -->
3723<div class="doc_subsubsection">
3724 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
3725</div>
3726<div class="doc_text">
3727
3728<h5>Syntax:</h5>
3729<pre>
3730 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3731</pre>
3732
3733<h5>Overview:</h5>
3734<p>The '<tt>zext</tt>' instruction zero extends its operand to type
3735<tt>ty2</tt>.</p>
3736
3737
3738<h5>Arguments:</h5>
3739<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3740<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3741also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3742<tt>value</tt> must be smaller than the bit size of the destination type,
3743<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3744
3745<h5>Semantics:</h5>
3746<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Chris Lattnerd1d25172007-05-24 19:13:27 +0000[diff] [blame]3747bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3748
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]3749<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]3750
3751<h5>Example:</h5>
3752<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3753 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3754 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3755</pre>
3756</div>
3757
3758<!-- _______________________________________________________________________ -->
3759<div class="doc_subsubsection">
3760 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3761</div>
3762<div class="doc_text">
3763
3764<h5>Syntax:</h5>
3765<pre>
3766 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3767</pre>
3768
3769<h5>Overview:</h5>
3770<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3771
3772<h5>Arguments:</h5>
3773<p>
3774The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3775<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3776also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3777<tt>value</tt> must be smaller than the bit size of the destination type,
3778<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3779
3780<h5>Semantics:</h5>
3781<p>
3782The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3783bit (highest order bit) of the <tt>value</tt> until it reaches the bit size of
Chris Lattnerd1d25172007-05-24 19:13:27 +0000[diff] [blame]3784the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3785
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3786<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]3787
3788<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3789<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3790 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3791 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3792</pre>
3793</div>
3794
3795<!-- _______________________________________________________________________ -->
3796<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3797 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3798</div>
3799
3800<div class="doc_text">
3801
3802<h5>Syntax:</h5>
3803
3804<pre>
3805 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3806</pre>
3807
3808<h5>Overview:</h5>
3809<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3810<tt>ty2</tt>.</p>
3811
3812
3813<h5>Arguments:</h5>
3814<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3815 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3816cast it to. The size of <tt>value</tt> must be larger than the size of
3817<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3818<i>no-op cast</i>.</p>
3819
3820<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3821<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3822<a href="#t_floating">floating point</a> type to a smaller
3823<a href="#t_floating">floating point</a> type. If the value cannot fit within
3824the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3825
3826<h5>Example:</h5>
3827<pre>
3828 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3829 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3830</pre>
3831</div>
3832
3833<!-- _______________________________________________________________________ -->
3834<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3835 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3836</div>
3837<div class="doc_text">
3838
3839<h5>Syntax:</h5>
3840<pre>
3841 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3842</pre>
3843
3844<h5>Overview:</h5>
3845<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3846floating point value.</p>
3847
3848<h5>Arguments:</h5>
3849<p>The '<tt>fpext</tt>' instruction takes a
3850<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3851and a <a href="#t_floating">floating point</a> type to cast it to. The source
3852type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3853
3854<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3855<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3856<a href="#t_floating">floating point</a> type to a larger
3857<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3858used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3859<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]3860
3861<h5>Example:</h5>
3862<pre>
3863 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3864 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3865</pre>
3866</div>
3867
3868<!-- _______________________________________________________________________ -->
3869<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]3870 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3871</div>
3872<div class="doc_text">
3873
3874<h5>Syntax:</h5>
3875<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3876 &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]3877</pre>
3878
3879<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3880<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3881unsigned integer equivalent of type <tt>ty2</tt>.
3882</p>
3883
3884<h5>Arguments:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3885<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3886scalar or vector <a href="#t_floating">floating point</a> value, and a type
3887to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3888type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3889vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3890
3891<h5>Semantics:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3892<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3893<a href="#t_floating">floating point</a> operand into the nearest (rounding
3894towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3895the results are undefined.</p>
3896
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3897<h5>Example:</h5>
3898<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3899 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3900 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3901 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3902</pre>
3903</div>
3904
3905<!-- _______________________________________________________________________ -->
3906<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3907 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3908</div>
3909<div class="doc_text">
3910
3911<h5>Syntax:</h5>
3912<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3913 &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]3914</pre>
3915
3916<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3917<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3918<a href="#t_floating">floating point</a> <tt>value</tt> to type <tt>ty2</tt>.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3919</p>
3920
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3921<h5>Arguments:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3922<p> The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3923scalar or vector <a href="#t_floating">floating point</a> value, and a type
3924to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3925type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3926vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3927
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3928<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3929<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3930<a href="#t_floating">floating point</a> operand into the nearest (rounding
3931towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3932the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3933
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3934<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3935<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3936 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3937 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3938 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3939</pre>
3940</div>
3941
3942<!-- _______________________________________________________________________ -->
3943<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3944 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3945</div>
3946<div class="doc_text">
3947
3948<h5>Syntax:</h5>
3949<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3950 &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]3951</pre>
3952
3953<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3954<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3955integer and converts that value to the <tt>ty2</tt> type.</p>
3956
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3957<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3958<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3959scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3960to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3961type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3962floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3963
3964<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3965<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3966integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3967the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3968
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3969<h5>Example:</h5>
3970<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3971 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3972 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3973</pre>
3974</div>
3975
3976<!-- _______________________________________________________________________ -->
3977<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3978 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3979</div>
3980<div class="doc_text">
3981
3982<h5>Syntax:</h5>
3983<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3984 &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]3985</pre>
3986
3987<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3988<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3989integer and converts that value to the <tt>ty2</tt> type.</p>
3990
3991<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3992<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3993scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3994to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3995type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3996floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3997
3998<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3999<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4000integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]4001the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4002
4003<h5>Example:</h5>
4004<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4005 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4006 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4007</pre>
4008</div>
4009
4010<!-- _______________________________________________________________________ -->
4011<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4012 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
4013</div>
4014<div class="doc_text">
4015
4016<h5>Syntax:</h5>
4017<pre>
4018 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4019</pre>
4020
4021<h5>Overview:</h5>
4022<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
4023the integer type <tt>ty2</tt>.</p>
4024
4025<h5>Arguments:</h5>
4026<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4027must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4028<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]4029
4030<h5>Semantics:</h5>
4031<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
4032<tt>ty2</tt> by interpreting the pointer value as an integer and either
4033truncating or zero extending that value to the size of the integer type. If
4034<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
4035<tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4036are the same size, then nothing is done (<i>no-op cast</i>) other than a type
4037change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4038
4039<h5>Example:</h5>
4040<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4041 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
4042 %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]4043</pre>
4044</div>
4045
4046<!-- _______________________________________________________________________ -->
4047<div class="doc_subsubsection">
4048 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
4049</div>
4050<div class="doc_text">
4051
4052<h5>Syntax:</h5>
4053<pre>
4054 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4055</pre>
4056
4057<h5>Overview:</h5>
4058<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
4059a pointer type, <tt>ty2</tt>.</p>
4060
4061<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4062<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4063value to cast, and a type to cast it to, which must be a
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4064<a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4065
4066<h5>Semantics:</h5>
4067<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
4068<tt>ty2</tt> by applying either a zero extension or a truncation depending on
4069the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
4070size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
4071the size of a pointer then a zero extension is done. If they are the same size,
4072nothing is done (<i>no-op cast</i>).</p>
4073
4074<h5>Example:</h5>
4075<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4076 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
4077 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
4078 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4079</pre>
4080</div>
4081
4082<!-- _______________________________________________________________________ -->
4083<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4084 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4085</div>
4086<div class="doc_text">
4087
4088<h5>Syntax:</h5>
4089<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4090 &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]4091</pre>
4092
4093<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4094
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4095<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4096<tt>ty2</tt> without changing any bits.</p>
4097
4098<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4099
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4100<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Dan Gohman500233a2008-09-08 16:45:59 +0000[diff] [blame]4101a non-aggregate first class value, and a type to cast it to, which must also be
4102a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
4103<tt>value</tt>
Reid Spencer19b569f2007-01-09 20:08:58 +0000[diff] [blame]4104and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4105type is a pointer, the destination type must also be a pointer. This
4106instruction supports bitwise conversion of vectors to integers and to vectors
4107of other types (as long as they have the same size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4108
4109<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4110<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4111<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
4112this conversion. The conversion is done as if the <tt>value</tt> had been
4113stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
4114converted to other pointer types with this instruction. To convert pointers to
4115other types, use the <a href="#i_inttoptr">inttoptr</a> or
4116<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4117
4118<h5>Example:</h5>
4119<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4120 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4121 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4122 %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]4123</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4124</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4125
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4126<!-- ======================================================================= -->
4127<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
4128<div class="doc_text">
4129<p>The instructions in this category are the "miscellaneous"
4130instructions, which defy better classification.</p>
4131</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4132
4133<!-- _______________________________________________________________________ -->
4134<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4135</div>
4136<div class="doc_text">
4137<h5>Syntax:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4138<pre> &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]4139</pre>
4140<h5>Overview:</h5>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4141<p>The '<tt>icmp</tt>' instruction returns a boolean value or
4142a vector of boolean values based on comparison
4143of its two integer, integer vector, or pointer operands.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4144<h5>Arguments:</h5>
4145<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4146the condition code indicating the kind of comparison to perform. It is not
4147a value, just a keyword. The possible condition code are:
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4148</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4149<ol>
4150 <li><tt>eq</tt>: equal</li>
4151 <li><tt>ne</tt>: not equal </li>
4152 <li><tt>ugt</tt>: unsigned greater than</li>
4153 <li><tt>uge</tt>: unsigned greater or equal</li>
4154 <li><tt>ult</tt>: unsigned less than</li>
4155 <li><tt>ule</tt>: unsigned less or equal</li>
4156 <li><tt>sgt</tt>: signed greater than</li>
4157 <li><tt>sge</tt>: signed greater or equal</li>
4158 <li><tt>slt</tt>: signed less than</li>
4159 <li><tt>sle</tt>: signed less or equal</li>
4160</ol>
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]4161<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4162<a href="#t_pointer">pointer</a>
4163or integer <a href="#t_vector">vector</a> typed.
4164They must also be identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4165<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4166<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4167the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4168yields either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt> result, as follows:
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4169</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4170<ol>
4171 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
4172 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
4173 </li>
4174 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4175 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4176 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4177 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4178 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4179 <tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4180 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4181 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4182 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4183 <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]4184 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4185 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4186 <li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4187 <tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4188 <li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4189 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4190 <li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4191 <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]4192</ol>
4193<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4194values are compared as if they were integers.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4195<p>If the operands are integer vectors, then they are compared
4196element by element. The result is an <tt>i1</tt> vector with
4197the same number of elements as the values being compared.
4198Otherwise, the result is an <tt>i1</tt>.
4199</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4200
4201<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4202<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
4203 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4204 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4205 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4206 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4207 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4208</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4209
4210<p>Note that the code generator does not yet support vector types with
4211 the <tt>icmp</tt> instruction.</p>
4212
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4213</div>
4214
4215<!-- _______________________________________________________________________ -->
4216<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4217</div>
4218<div class="doc_text">
4219<h5>Syntax:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4220<pre> &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]4221</pre>
4222<h5>Overview:</h5>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4223<p>The '<tt>fcmp</tt>' instruction returns a boolean value
4224or vector of boolean values based on comparison
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4225of its operands.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4226<p>
4227If the operands are floating point scalars, then the result
4228type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
4229</p>
4230<p>If the operands are floating point vectors, then the result type
4231is a vector of boolean with the same number of elements as the
4232operands being compared.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4233<h5>Arguments:</h5>
4234<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4235the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4236a value, just a keyword. The possible condition code are:</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4237<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4238 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4239 <li><tt>oeq</tt>: ordered and equal</li>
4240 <li><tt>ogt</tt>: ordered and greater than </li>
4241 <li><tt>oge</tt>: ordered and greater than or equal</li>
4242 <li><tt>olt</tt>: ordered and less than </li>
4243 <li><tt>ole</tt>: ordered and less than or equal</li>
4244 <li><tt>one</tt>: ordered and not equal</li>
4245 <li><tt>ord</tt>: ordered (no nans)</li>
4246 <li><tt>ueq</tt>: unordered or equal</li>
4247 <li><tt>ugt</tt>: unordered or greater than </li>
4248 <li><tt>uge</tt>: unordered or greater than or equal</li>
4249 <li><tt>ult</tt>: unordered or less than </li>
4250 <li><tt>ule</tt>: unordered or less than or equal</li>
4251 <li><tt>une</tt>: unordered or not equal</li>
4252 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4253 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4254</ol>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4255<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer93a49852006-12-06 07:08:07 +0000[diff] [blame]4256<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4257<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
4258either a <a href="#t_floating">floating point</a> type
4259or a <a href="#t_vector">vector</a> of floating point type.
4260They must have identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4261<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4262<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4263according to the condition code given as <tt>cond</tt>.
4264If the operands are vectors, then the vectors are compared
4265element by element.
4266Each comparison performed
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4267always yields an <a href="#t_primitive">i1</a> result, as follows:</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4268<ol>
4269 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4270 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4271 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4272 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4273 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4274 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4275 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4276 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4277 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4278 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4279 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4280 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4281 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4282 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
4283 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4284 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4285 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4286 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4287 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4288 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4289 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4290 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4291 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4292 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4293 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4294 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4295 <li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4296 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4297</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4298
4299<h5>Example:</h5>
4300<pre> &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]4301 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4302 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4303 &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]4304</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4305
4306<p>Note that the code generator does not yet support vector types with
4307 the <tt>fcmp</tt> instruction.</p>
4308
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4309</div>
4310
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4311<!-- _______________________________________________________________________ -->
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4312<div class="doc_subsubsection">
4313 <a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
4314</div>
4315<div class="doc_text">
4316<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4317<pre> &lt;result&gt; = vicmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4318</pre>
4319<h5>Overview:</h5>
4320<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
4321element-wise comparison of its two integer vector operands.</p>
4322<h5>Arguments:</h5>
4323<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
4324the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4325a value, just a keyword. The possible condition code are:</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4326<ol>
4327 <li><tt>eq</tt>: equal</li>
4328 <li><tt>ne</tt>: not equal </li>
4329 <li><tt>ugt</tt>: unsigned greater than</li>
4330 <li><tt>uge</tt>: unsigned greater or equal</li>
4331 <li><tt>ult</tt>: unsigned less than</li>
4332 <li><tt>ule</tt>: unsigned less or equal</li>
4333 <li><tt>sgt</tt>: signed greater than</li>
4334 <li><tt>sge</tt>: signed greater or equal</li>
4335 <li><tt>slt</tt>: signed less than</li>
4336 <li><tt>sle</tt>: signed less or equal</li>
4337</ol>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4338<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4339<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
4340<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4341<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4342according to the condition code given as <tt>cond</tt>. The comparison yields a
4343<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
4344identical type as the values being compared. The most significant bit in each
4345element is 1 if the element-wise comparison evaluates to true, and is 0
4346otherwise. All other bits of the result are undefined. The condition codes
4347are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4348instruction</a>.</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4349
4350<h5>Example:</h5>
4351<pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4352 &lt;result&gt; = vicmp eq &lt;2 x i32&gt; &lt; i32 4, i32 0&gt;, &lt; i32 5, i32 0&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0, i32 -1 &gt;</i>
4353 &lt;result&gt; = vicmp ult &lt;2 x i8 &gt; &lt; i8 1, i8 2&gt;, &lt; i8 2, i8 2 &gt; <i>; yields: result=&lt;2 x i8&gt; &lt; i8 -1, i8 0 &gt;</i>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4354</pre>
4355</div>
4356
4357<!-- _______________________________________________________________________ -->
4358<div class="doc_subsubsection">
4359 <a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
4360</div>
4361<div class="doc_text">
4362<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4363<pre> &lt;result&gt; = vfcmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt;</pre>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4364<h5>Overview:</h5>
4365<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
4366element-wise comparison of its two floating point vector operands. The output
4367elements have the same width as the input elements.</p>
4368<h5>Arguments:</h5>
4369<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
4370the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4371a value, just a keyword. The possible condition code are:</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4372<ol>
4373 <li><tt>false</tt>: no comparison, always returns false</li>
4374 <li><tt>oeq</tt>: ordered and equal</li>
4375 <li><tt>ogt</tt>: ordered and greater than </li>
4376 <li><tt>oge</tt>: ordered and greater than or equal</li>
4377 <li><tt>olt</tt>: ordered and less than </li>
4378 <li><tt>ole</tt>: ordered and less than or equal</li>
4379 <li><tt>one</tt>: ordered and not equal</li>
4380 <li><tt>ord</tt>: ordered (no nans)</li>
4381 <li><tt>ueq</tt>: unordered or equal</li>
4382 <li><tt>ugt</tt>: unordered or greater than </li>
4383 <li><tt>uge</tt>: unordered or greater than or equal</li>
4384 <li><tt>ult</tt>: unordered or less than </li>
4385 <li><tt>ule</tt>: unordered or less than or equal</li>
4386 <li><tt>une</tt>: unordered or not equal</li>
4387 <li><tt>uno</tt>: unordered (either nans)</li>
4388 <li><tt>true</tt>: no comparison, always returns true</li>
4389</ol>
4390<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
4391<a href="#t_floating">floating point</a> typed. They must also be identical
4392types.</p>
4393<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4394<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4395according to the condition code given as <tt>cond</tt>. The comparison yields a
4396<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
4397an identical number of elements as the values being compared, and each element
4398having identical with to the width of the floating point elements. The most
4399significant bit in each element is 1 if the element-wise comparison evaluates to
4400true, and is 0 otherwise. All other bits of the result are undefined. The
4401condition codes are evaluated identically to the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4402<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4403
4404<h5>Example:</h5>
4405<pre>
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]4406 <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0, i32 -1 &gt;</i>
4407 &lt;result&gt; = vfcmp oeq &lt;2 x float&gt; &lt; float 4, float 0 &gt;, &lt; float 5, float 0 &gt;
4408
4409 <i>; yields: result=&lt;2 x i64&gt; &lt; i64 -1, i64 0 &gt;</i>
4410 &lt;result&gt; = vfcmp ult &lt;2 x double&gt; &lt; double 1, double 2 &gt;, &lt; double 2, double 2&gt;
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4411</pre>
4412</div>
4413
4414<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4415<div class="doc_subsubsection">
4416 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4417</div>
4418
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4419<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4420
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4421<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4422
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4423<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
4424<h5>Overview:</h5>
4425<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
4426the SSA graph representing the function.</p>
4427<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4428
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4429<p>The type of the incoming values is specified with the first type
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4430field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
4431as arguments, with one pair for each predecessor basic block of the
4432current block. Only values of <a href="#t_firstclass">first class</a>
4433type may be used as the value arguments to the PHI node. Only labels
4434may be used as the label arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4435
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4436<p>There must be no non-phi instructions between the start of a basic
4437block and the PHI instructions: i.e. PHI instructions must be first in
4438a basic block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4439
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4440<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4441
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4442<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
4443specified by the pair corresponding to the predecessor basic block that executed
4444just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4445
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4446<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4447<pre>
4448Loop: ; Infinite loop that counts from 0 on up...
4449 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4450 %nextindvar = add i32 %indvar, 1
4451 br label %Loop
4452</pre>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4453</div>
4454
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4455<!-- _______________________________________________________________________ -->
4456<div class="doc_subsubsection">
4457 <a name="i_select">'<tt>select</tt>' Instruction</a>
4458</div>
4459
4460<div class="doc_text">
4461
4462<h5>Syntax:</h5>
4463
4464<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4465 &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>
4466
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4467 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4468</pre>
4469
4470<h5>Overview:</h5>
4471
4472<p>
4473The '<tt>select</tt>' instruction is used to choose one value based on a
4474condition, without branching.
4475</p>
4476
4477
4478<h5>Arguments:</h5>
4479
4480<p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4481The '<tt>select</tt>' instruction requires an 'i1' value or
4482a vector of 'i1' values indicating the
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4483condition, and two values of the same <a href="#t_firstclass">first class</a>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4484type. If the val1/val2 are vectors and
4485the condition is a scalar, then entire vectors are selected, not
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4486individual elements.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4487</p>
4488
4489<h5>Semantics:</h5>
4490
4491<p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4492If the condition is an i1 and it evaluates to 1, the instruction returns the first
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4493value argument; otherwise, it returns the second value argument.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4494</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4495<p>
4496If the condition is a vector of i1, then the value arguments must
4497be vectors of the same size, and the selection is done element
4498by element.
4499</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4500
4501<h5>Example:</h5>
4502
4503<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4504 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4505</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4506
4507<p>Note that the code generator does not yet support conditions
4508 with vector type.</p>
4509
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4510</div>
4511
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]4512
4513<!-- _______________________________________________________________________ -->
4514<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4515 <a name="i_call">'<tt>call</tt>' Instruction</a>
4516</div>
4517
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4518<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4519
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4520<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4521<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]4522 &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]4523</pre>
4524
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4525<h5>Overview:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4526
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4527<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4528
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4529<h5>Arguments:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4530
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4531<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4532
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4533<ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4534 <li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4535 <p>The optional "tail" marker indicates whether the callee function accesses
4536 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4537 function call is eligible for tail call optimization. Note that calls may
4538 be marked "tail" even if they do not occur before a <a
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4539 href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4540 </li>
4541 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4542 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4543 convention</a> the call should use. If none is specified, the call defaults
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4544 to using C calling conventions.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4545 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4546
4547 <li>
4548 <p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4549 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
4550 and '<tt>inreg</tt>' attributes are valid here.</p>
4551 </li>
4552
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4553 <li>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4554 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
4555 the type of the return value. Functions that return no value are marked
4556 <tt><a href="#t_void">void</a></tt>.</p>
4557 </li>
4558 <li>
4559 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
4560 value being invoked. The argument types must match the types implied by
4561 this signature. This type can be omitted if the function is not varargs
4562 and if the function type does not return a pointer to a function.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4563 </li>
4564 <li>
4565 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4566 be invoked. In most cases, this is a direct function invocation, but
4567 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4568 to function value.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4569 </li>
4570 <li>
4571 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencera7e302a2005-05-01 22:22:57 +0000[diff] [blame]4572 function signature argument types. All arguments must be of
4573 <a href="#t_firstclass">first class</a> type. If the function signature
4574 indicates the function accepts a variable number of arguments, the extra
4575 arguments can be specified.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4576 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4577 <li>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]4578 <p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4579 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
4580 '<tt>readnone</tt>' attributes are valid here.</p>
4581 </li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4582</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4583
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4584<h5>Semantics:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4585
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4586<p>The '<tt>call</tt>' instruction is used to cause control flow to
4587transfer to a specified function, with its incoming arguments bound to
4588the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
4589instruction in the called function, control flow continues with the
4590instruction after the function call, and the return value of the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4591function is bound to the result argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4592
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4593<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4594
4595<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4596 %retval = call i32 @test(i32 %argc)
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]4597 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4598 %X = tail call i32 @foo() <i>; yields i32</i>
4599 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4600 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]4601
4602 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4603 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]4604 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
4605 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]4606 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]4607 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4608</pre>
4609
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4610</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4611
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4612<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4613<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]4614 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4615</div>
4616
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4617<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4618
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4619<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4620
4621<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4622 &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]4623</pre>
4624
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4625<h5>Overview:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4626
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4627<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4628the "variable argument" area of a function call. It is used to implement the
4629<tt>va_arg</tt> macro in C.</p>
4630
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4631<h5>Arguments:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4632
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4633<p>This instruction takes a <tt>va_list*</tt> value and the type of
4634the argument. It returns a value of the specified argument type and
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4635increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4636actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4637
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4638<h5>Semantics:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4639
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4640<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
4641type from the specified <tt>va_list</tt> and causes the
4642<tt>va_list</tt> to point to the next argument. For more information,
4643see the variable argument handling <a href="#int_varargs">Intrinsic
4644Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4645
4646<p>It is legal for this instruction to be called in a function which does not
4647take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4648function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4649
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4650<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4651href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4652argument.</p>
4653
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4654<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4655
4656<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4657
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]4658<p>Note that the code generator does not yet fully support va_arg
4659 on many targets. Also, it does not currently support va_arg with
4660 aggregate types on any target.</p>
4661
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4662</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4663
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4664<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4665<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4666<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4667
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4668<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4669
4670<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4671well known names and semantics and are required to follow certain restrictions.
4672Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4673language that does not require changing all of the transformations in LLVM when
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]4674adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4675
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4676<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4677prefix is reserved in LLVM for intrinsic names; thus, function names may not
4678begin with this prefix. Intrinsic functions must always be external functions:
4679you cannot define the body of intrinsic functions. Intrinsic functions may
4680only be used in call or invoke instructions: it is illegal to take the address
4681of an intrinsic function. Additionally, because intrinsic functions are part
4682of the LLVM language, it is required if any are added that they be documented
4683here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4684
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4685<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
4686a family of functions that perform the same operation but on different data
4687types. Because LLVM can represent over 8 million different integer types,
4688overloading is used commonly to allow an intrinsic function to operate on any
4689integer type. One or more of the argument types or the result type can be
4690overloaded to accept any integer type. Argument types may also be defined as
4691exactly matching a previous argument's type or the result type. This allows an
4692intrinsic function which accepts multiple arguments, but needs all of them to
4693be of the same type, to only be overloaded with respect to a single argument or
4694the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4695
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4696<p>Overloaded intrinsics will have the names of its overloaded argument types
4697encoded into its function name, each preceded by a period. Only those types
4698which are overloaded result in a name suffix. Arguments whose type is matched
4699against another type do not. For example, the <tt>llvm.ctpop</tt> function can
4700take an integer of any width and returns an integer of exactly the same integer
4701width. This leads to a family of functions such as
4702<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
4703Only one type, the return type, is overloaded, and only one type suffix is
4704required. Because the argument's type is matched against the return type, it
4705does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4706
4707<p>To learn how to add an intrinsic function, please see the
4708<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4709</p>
4710
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4711</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4712
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4713<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4714<div class="doc_subsection">
4715 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
4716</div>
4717
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4718<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4719
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4720<p>Variable argument support is defined in LLVM with the <a
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]4721 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4722intrinsic functions. These functions are related to the similarly
4723named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4724
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4725<p>All of these functions operate on arguments that use a
4726target-specific value type "<tt>va_list</tt>". The LLVM assembly
4727language reference manual does not define what this type is, so all
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4728transformations should be prepared to handle these functions regardless of
4729the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4730
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]4731<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4732instruction and the variable argument handling intrinsic functions are
4733used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4734
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4735<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4736<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4737define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4738 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4739 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4740 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4741 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4742
4743 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4744 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4745
4746 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4747 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4748 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4749 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4750 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4751
4752 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4753 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4754 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4755}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4756
4757declare void @llvm.va_start(i8*)
4758declare void @llvm.va_copy(i8*, i8*)
4759declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4760</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4761</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4762
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4763</div>
4764
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4765<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4766<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4767 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4768</div>
4769
4770
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4771<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4772<h5>Syntax:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4773<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4774<h5>Overview:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4775<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4776<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
4777href="#i_va_arg">va_arg</a></tt>.</p>
4778
4779<h5>Arguments:</h5>
4780
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4781<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]4782
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4783<h5>Semantics:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4784
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4785<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4786macro available in C. In a target-dependent way, it initializes the
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4787<tt>va_list</tt> element to which the argument points, so that the next call to
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4788<tt>va_arg</tt> will produce the first variable argument passed to the function.
4789Unlike the C <tt>va_start</tt> macro, this intrinsic does not need to know the
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4790last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4791
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4792</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4793
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4794<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4795<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4796 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4797</div>
4798
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4799<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4800<h5>Syntax:</h5>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4801<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4802<h5>Overview:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4803
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4804<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4805which has been initialized previously with <tt><a href="#int_va_start">llvm.va_start</a></tt>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4806or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4807
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4808<h5>Arguments:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4809
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4810<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]4811
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4812<h5>Semantics:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4813
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4814<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4815macro available in C. In a target-dependent way, it destroys the
4816<tt>va_list</tt> element to which the argument points. Calls to <a
4817href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
4818<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
4819<tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4820
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4821</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4822
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4823<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4824<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4825 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4826</div>
4827
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4828<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4829
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4830<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4831
4832<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4833 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4834</pre>
4835
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4836<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4837
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4838<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
4839from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4840
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4841<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4842
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4843<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Andrew Lenharthd0a4c622005-06-22 20:38:11 +0000[diff] [blame]4844The second argument is a pointer to a <tt>va_list</tt> element to copy from.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4845
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4846
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4847<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4848
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4849<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
4850macro available in C. In a target-dependent way, it copies the source
4851<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
4852intrinsic is necessary because the <tt><a href="#int_va_start">
4853llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
4854example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4855
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4856</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4857
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4858<!-- ======================================================================= -->
4859<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4860 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
4861</div>
4862
4863<div class="doc_text">
4864
4865<p>
4866LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]4867Collection</a> (GC) requires the implementation and generation of these
4868intrinsics.
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4869These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4870stack</a>, as well as garbage collector implementations that require <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4871href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4872Front-ends for type-safe garbage collected languages should generate these
4873intrinsics to make use of the LLVM garbage collectors. For more details, see <a
4874href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
4875</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]4876
4877<p>The garbage collection intrinsics only operate on objects in the generic
4878 address space (address space zero).</p>
4879
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4880</div>
4881
4882<!-- _______________________________________________________________________ -->
4883<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4884 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4885</div>
4886
4887<div class="doc_text">
4888
4889<h5>Syntax:</h5>
4890
4891<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4892 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4893</pre>
4894
4895<h5>Overview:</h5>
4896
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]4897<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4898the code generator, and allows some metadata to be associated with it.</p>
4899
4900<h5>Arguments:</h5>
4901
4902<p>The first argument specifies the address of a stack object that contains the
4903root pointer. The second pointer (which must be either a constant or a global
4904value address) contains the meta-data to be associated with the root.</p>
4905
4906<h5>Semantics:</h5>
4907
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]4908<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4909location. At compile-time, the code generator generates information to allow
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4910the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
4911intrinsic may only be used in a function which <a href="#gc">specifies a GC
4912algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4913
4914</div>
4915
4916
4917<!-- _______________________________________________________________________ -->
4918<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4919 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4920</div>
4921
4922<div class="doc_text">
4923
4924<h5>Syntax:</h5>
4925
4926<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4927 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4928</pre>
4929
4930<h5>Overview:</h5>
4931
4932<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4933locations, allowing garbage collector implementations that require read
4934barriers.</p>
4935
4936<h5>Arguments:</h5>
4937
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4938<p>The second argument is the address to read from, which should be an address
4939allocated from the garbage collector. The first object is a pointer to the
4940start of the referenced object, if needed by the language runtime (otherwise
4941null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4942
4943<h5>Semantics:</h5>
4944
4945<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4946instruction, but may be replaced with substantially more complex code by the
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4947garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
4948may only be used in a function which <a href="#gc">specifies a GC
4949algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4950
4951</div>
4952
4953
4954<!-- _______________________________________________________________________ -->
4955<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4956 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4957</div>
4958
4959<div class="doc_text">
4960
4961<h5>Syntax:</h5>
4962
4963<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4964 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4965</pre>
4966
4967<h5>Overview:</h5>
4968
4969<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4970locations, allowing garbage collector implementations that require write
4971barriers (such as generational or reference counting collectors).</p>
4972
4973<h5>Arguments:</h5>
4974
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4975<p>The first argument is the reference to store, the second is the start of the
4976object to store it to, and the third is the address of the field of Obj to
4977store to. If the runtime does not require a pointer to the object, Obj may be
4978null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4979
4980<h5>Semantics:</h5>
4981
4982<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4983instruction, but may be replaced with substantially more complex code by the
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4984garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
4985may only be used in a function which <a href="#gc">specifies a GC
4986algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4987
4988</div>
4989
4990
4991
4992<!-- ======================================================================= -->
4993<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4994 <a name="int_codegen">Code Generator Intrinsics</a>
4995</div>
4996
4997<div class="doc_text">
4998<p>
4999These intrinsics are provided by LLVM to expose special features that may only
5000be implemented with code generator support.
5001</p>
5002
5003</div>
5004
5005<!-- _______________________________________________________________________ -->
5006<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5007 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5008</div>
5009
5010<div class="doc_text">
5011
5012<h5>Syntax:</h5>
5013<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5014 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5015</pre>
5016
5017<h5>Overview:</h5>
5018
5019<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]5020The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5021target-specific value indicating the return address of the current function
5022or one of its callers.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5023</p>
5024
5025<h5>Arguments:</h5>
5026
5027<p>
5028The argument to this intrinsic indicates which function to return the address
5029for. Zero indicates the calling function, one indicates its caller, etc. The
5030argument is <b>required</b> to be a constant integer value.
5031</p>
5032
5033<h5>Semantics:</h5>
5034
5035<p>
5036The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
5037the return address of the specified call frame, or zero if it cannot be
5038identified. The value returned by this intrinsic is likely to be incorrect or 0
5039for arguments other than zero, so it should only be used for debugging purposes.
5040</p>
5041
5042<p>
5043Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]5044aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5045source-language caller.
5046</p>
5047</div>
5048
5049
5050<!-- _______________________________________________________________________ -->
5051<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5052 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5053</div>
5054
5055<div class="doc_text">
5056
5057<h5>Syntax:</h5>
5058<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5059 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5060</pre>
5061
5062<h5>Overview:</h5>
5063
5064<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]5065The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5066target-specific frame pointer value for the specified stack frame.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5067</p>
5068
5069<h5>Arguments:</h5>
5070
5071<p>
5072The argument to this intrinsic indicates which function to return the frame
5073pointer for. Zero indicates the calling function, one indicates its caller,
5074etc. The argument is <b>required</b> to be a constant integer value.
5075</p>
5076
5077<h5>Semantics:</h5>
5078
5079<p>
5080The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
5081the frame address of the specified call frame, or zero if it cannot be
5082identified. The value returned by this intrinsic is likely to be incorrect or 0
5083for arguments other than zero, so it should only be used for debugging purposes.
5084</p>
5085
5086<p>
5087Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]5088aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5089source-language caller.
5090</p>
5091</div>
5092
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5093<!-- _______________________________________________________________________ -->
5094<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5095 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5096</div>
5097
5098<div class="doc_text">
5099
5100<h5>Syntax:</h5>
5101<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5102 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5103</pre>
5104
5105<h5>Overview:</h5>
5106
5107<p>
5108The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5109the function stack, for use with <a href="#int_stackrestore">
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5110<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
5111features like scoped automatic variable sized arrays in C99.
5112</p>
5113
5114<h5>Semantics:</h5>
5115
5116<p>
5117This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5118href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5119<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
5120<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
5121state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
5122practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
5123that were allocated after the <tt>llvm.stacksave</tt> was executed.
5124</p>
5125
5126</div>
5127
5128<!-- _______________________________________________________________________ -->
5129<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5130 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5131</div>
5132
5133<div class="doc_text">
5134
5135<h5>Syntax:</h5>
5136<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5137 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5138</pre>
5139
5140<h5>Overview:</h5>
5141
5142<p>
5143The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5144the function stack to the state it was in when the corresponding <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5145href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5146useful for implementing language features like scoped automatic variable sized
5147arrays in C99.
5148</p>
5149
5150<h5>Semantics:</h5>
5151
5152<p>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5153See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5154</p>
5155
5156</div>
5157
5158
5159<!-- _______________________________________________________________________ -->
5160<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5161 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5162</div>
5163
5164<div class="doc_text">
5165
5166<h5>Syntax:</h5>
5167<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5168 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]5169</pre>
5170
5171<h5>Overview:</h5>
5172
5173
5174<p>
5175The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5176a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
5177no
5178effect on the behavior of the program but can change its performance
Chris Lattner2a615362005-02-28 19:47:14 +0000[diff] [blame]5179characteristics.
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5180</p>
5181
5182<h5>Arguments:</h5>
5183
5184<p>
5185<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
5186determining if the fetch should be for a read (0) or write (1), and
5187<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattneraeffb4a2005-03-07 20:31:38 +0000[diff] [blame]5188locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5189<tt>locality</tt> arguments must be constant integers.
5190</p>
5191
5192<h5>Semantics:</h5>
5193
5194<p>
5195This intrinsic does not modify the behavior of the program. In particular,
5196prefetches cannot trap and do not produce a value. On targets that support this
5197intrinsic, the prefetch can provide hints to the processor cache for better
5198performance.
5199</p>
5200
5201</div>
5202
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5203<!-- _______________________________________________________________________ -->
5204<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5205 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5206</div>
5207
5208<div class="doc_text">
5209
5210<h5>Syntax:</h5>
5211<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5212 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5213</pre>
5214
5215<h5>Overview:</h5>
5216
5217
5218<p>
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5219The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5220(PC) in a region of
5221code to simulators and other tools. The method is target specific, but it is
5222expected that the marker will use exported symbols to transmit the PC of the
5223marker.
5224The marker makes no guarantees that it will remain with any specific instruction
5225after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb3e7afd2006-03-24 07:16:10 +0000[diff] [blame]5226optimizations. The intended use is to be inserted after optimizations to allow
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5227correlations of simulation runs.
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5228</p>
5229
5230<h5>Arguments:</h5>
5231
5232<p>
5233<tt>id</tt> is a numerical id identifying the marker.
5234</p>
5235
5236<h5>Semantics:</h5>
5237
5238<p>
5239This intrinsic does not modify the behavior of the program. Backends that do not
5240support this intrinisic may ignore it.
5241</p>
5242
5243</div>
5244
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5245<!-- _______________________________________________________________________ -->
5246<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5247 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5248</div>
5249
5250<div class="doc_text">
5251
5252<h5>Syntax:</h5>
5253<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5254 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5255</pre>
5256
5257<h5>Overview:</h5>
5258
5259
5260<p>
5261The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5262counter register (or similar low latency, high accuracy clocks) on those targets
5263that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
5264As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
5265should only be used for small timings.
5266</p>
5267
5268<h5>Semantics:</h5>
5269
5270<p>
5271When directly supported, reading the cycle counter should not modify any memory.
5272Implementations are allowed to either return a application specific value or a
5273system wide value. On backends without support, this is lowered to a constant 0.
5274</p>
5275
5276</div>
5277
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5278<!-- ======================================================================= -->
5279<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5280 <a name="int_libc">Standard C Library Intrinsics</a>
5281</div>
5282
5283<div class="doc_text">
5284<p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5285LLVM provides intrinsics for a few important standard C library functions.
5286These intrinsics allow source-language front-ends to pass information about the
5287alignment of the pointer arguments to the code generator, providing opportunity
5288for more efficient code generation.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5289</p>
5290
5291</div>
5292
5293<!-- _______________________________________________________________________ -->
5294<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5295 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5296</div>
5297
5298<div class="doc_text">
5299
5300<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5301<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
5302width. Not all targets support all bit widths however.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5303<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5304 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5305 i8 &lt;len&gt;, i32 &lt;align&gt;)
5306 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5307 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5308 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5309 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5310 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5311 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5312</pre>
5313
5314<h5>Overview:</h5>
5315
5316<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5317The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5318location to the destination location.
5319</p>
5320
5321<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5322Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5323intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5324</p>
5325
5326<h5>Arguments:</h5>
5327
5328<p>
5329The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5330the source. The third argument is an integer argument
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5331specifying the number of bytes to copy, and the fourth argument is the alignment
5332of the source and destination locations.
5333</p>
5334
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5335<p>
5336If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattnerf0afc2c2006-03-04 00:02:10 +0000[diff] [blame]5337the caller guarantees that both the source and destination pointers are aligned
5338to that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5339</p>
5340
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5341<h5>Semantics:</h5>
5342
5343<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5344The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5345location to the destination location, which are not allowed to overlap. It
5346copies "len" bytes of memory over. If the argument is known to be aligned to
5347some boundary, this can be specified as the fourth argument, otherwise it should
5348be set to 0 or 1.
5349</p>
5350</div>
5351
5352
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5353<!-- _______________________________________________________________________ -->
5354<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5355 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5356</div>
5357
5358<div class="doc_text">
5359
5360<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5361<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
5362width. Not all targets support all bit widths however.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5363<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5364 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5365 i8 &lt;len&gt;, i32 &lt;align&gt;)
5366 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5367 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5368 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5369 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5370 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5371 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5372</pre>
5373
5374<h5>Overview:</h5>
5375
5376<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5377The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
5378location to the destination location. It is similar to the
Chris Lattner4b2cbcf2008-01-06 19:51:52 +0000[diff] [blame]5379'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5380</p>
5381
5382<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5383Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5384intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5385</p>
5386
5387<h5>Arguments:</h5>
5388
5389<p>
5390The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5391the source. The third argument is an integer argument
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5392specifying the number of bytes to copy, and the fourth argument is the alignment
5393of the source and destination locations.
5394</p>
5395
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5396<p>
5397If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattnerf0afc2c2006-03-04 00:02:10 +0000[diff] [blame]5398the caller guarantees that the source and destination pointers are aligned to
5399that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5400</p>
5401
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5402<h5>Semantics:</h5>
5403
5404<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5405The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5406location to the destination location, which may overlap. It
5407copies "len" bytes of memory over. If the argument is known to be aligned to
5408some boundary, this can be specified as the fourth argument, otherwise it should
5409be set to 0 or 1.
5410</p>
5411</div>
5412
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5413
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5414<!-- _______________________________________________________________________ -->
5415<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5416 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5417</div>
5418
5419<div class="doc_text">
5420
5421<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5422<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
5423width. Not all targets support all bit widths however.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5424<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5425 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5426 i8 &lt;len&gt;, i32 &lt;align&gt;)
5427 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5428 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5429 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5430 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5431 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5432 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5433</pre>
5434
5435<h5>Overview:</h5>
5436
5437<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5438The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5439byte value.
5440</p>
5441
5442<p>
5443Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
5444does not return a value, and takes an extra alignment argument.
5445</p>
5446
5447<h5>Arguments:</h5>
5448
5449<p>
5450The first argument is a pointer to the destination to fill, the second is the
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5451byte value to fill it with, the third argument is an integer
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5452argument specifying the number of bytes to fill, and the fourth argument is the
5453known alignment of destination location.
5454</p>
5455
5456<p>
5457If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattnerf0afc2c2006-03-04 00:02:10 +0000[diff] [blame]5458the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5459</p>
5460
5461<h5>Semantics:</h5>
5462
5463<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5464The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
5465the
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5466destination location. If the argument is known to be aligned to some boundary,
5467this can be specified as the fourth argument, otherwise it should be set to 0 or
54681.
5469</p>
5470</div>
5471
5472
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5473<!-- _______________________________________________________________________ -->
5474<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5475 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5476</div>
5477
5478<div class="doc_text">
5479
5480<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5481<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5482floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5483types however.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5484<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5485 declare float @llvm.sqrt.f32(float %Val)
5486 declare double @llvm.sqrt.f64(double %Val)
5487 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5488 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5489 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5490</pre>
5491
5492<h5>Overview:</h5>
5493
5494<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5495The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5496returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5497<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner103e2d72008-01-29 07:00:44 +0000[diff] [blame]5498negative numbers other than -0.0 (which allows for better optimization, because
5499there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
5500defined to return -0.0 like IEEE sqrt.
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5501</p>
5502
5503<h5>Arguments:</h5>
5504
5505<p>
5506The argument and return value are floating point numbers of the same type.
5507</p>
5508
5509<h5>Semantics:</h5>
5510
5511<p>
Dan Gohmand6257fe2007-07-16 14:37:41 +0000[diff] [blame]5512This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5513floating point number.
5514</p>
5515</div>
5516
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5517<!-- _______________________________________________________________________ -->
5518<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5519 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5520</div>
5521
5522<div class="doc_text">
5523
5524<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5525<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5526floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5527types however.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5528<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5529 declare float @llvm.powi.f32(float %Val, i32 %power)
5530 declare double @llvm.powi.f64(double %Val, i32 %power)
5531 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5532 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5533 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5534</pre>
5535
5536<h5>Overview:</h5>
5537
5538<p>
5539The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5540specified (positive or negative) power. The order of evaluation of
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5541multiplications is not defined. When a vector of floating point type is
5542used, the second argument remains a scalar integer value.
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5543</p>
5544
5545<h5>Arguments:</h5>
5546
5547<p>
5548The second argument is an integer power, and the first is a value to raise to
5549that power.
5550</p>
5551
5552<h5>Semantics:</h5>
5553
5554<p>
5555This function returns the first value raised to the second power with an
5556unspecified sequence of rounding operations.</p>
5557</div>
5558
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5559<!-- _______________________________________________________________________ -->
5560<div class="doc_subsubsection">
5561 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5562</div>
5563
5564<div class="doc_text">
5565
5566<h5>Syntax:</h5>
5567<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5568floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5569types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5570<pre>
5571 declare float @llvm.sin.f32(float %Val)
5572 declare double @llvm.sin.f64(double %Val)
5573 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5574 declare fp128 @llvm.sin.f128(fp128 %Val)
5575 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5576</pre>
5577
5578<h5>Overview:</h5>
5579
5580<p>
5581The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
5582</p>
5583
5584<h5>Arguments:</h5>
5585
5586<p>
5587The argument and return value are floating point numbers of the same type.
5588</p>
5589
5590<h5>Semantics:</h5>
5591
5592<p>
5593This function returns the sine of the specified operand, returning the
5594same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5595conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5596</div>
5597
5598<!-- _______________________________________________________________________ -->
5599<div class="doc_subsubsection">
5600 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5601</div>
5602
5603<div class="doc_text">
5604
5605<h5>Syntax:</h5>
5606<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5607floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5608types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5609<pre>
5610 declare float @llvm.cos.f32(float %Val)
5611 declare double @llvm.cos.f64(double %Val)
5612 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5613 declare fp128 @llvm.cos.f128(fp128 %Val)
5614 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5615</pre>
5616
5617<h5>Overview:</h5>
5618
5619<p>
5620The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
5621</p>
5622
5623<h5>Arguments:</h5>
5624
5625<p>
5626The argument and return value are floating point numbers of the same type.
5627</p>
5628
5629<h5>Semantics:</h5>
5630
5631<p>
5632This function returns the cosine of the specified operand, returning the
5633same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5634conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5635</div>
5636
5637<!-- _______________________________________________________________________ -->
5638<div class="doc_subsubsection">
5639 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5640</div>
5641
5642<div class="doc_text">
5643
5644<h5>Syntax:</h5>
5645<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5646floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5647types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5648<pre>
5649 declare float @llvm.pow.f32(float %Val, float %Power)
5650 declare double @llvm.pow.f64(double %Val, double %Power)
5651 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5652 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5653 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5654</pre>
5655
5656<h5>Overview:</h5>
5657
5658<p>
5659The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5660specified (positive or negative) power.
5661</p>
5662
5663<h5>Arguments:</h5>
5664
5665<p>
5666The second argument is a floating point power, and the first is a value to
5667raise to that power.
5668</p>
5669
5670<h5>Semantics:</h5>
5671
5672<p>
5673This function returns the first value raised to the second power,
5674returning the
5675same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5676conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5677</div>
5678
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5679
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5680<!-- ======================================================================= -->
5681<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5682 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5683</div>
5684
5685<div class="doc_text">
5686<p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5687LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5688These allow efficient code generation for some algorithms.
5689</p>
5690
5691</div>
5692
5693<!-- _______________________________________________________________________ -->
5694<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5695 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5696</div>
5697
5698<div class="doc_text">
5699
5700<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5701<p>This is an overloaded intrinsic function. You can use bswap on any integer
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5702type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5703<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5704 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5705 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5706 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5707</pre>
5708
5709<h5>Overview:</h5>
5710
5711<p>
Reid Spencer338ea092007-04-02 02:25:19 +0000[diff] [blame]5712The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5713values with an even number of bytes (positive multiple of 16 bits). These are
5714useful for performing operations on data that is not in the target's native
5715byte order.
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5716</p>
5717
5718<h5>Semantics:</h5>
5719
5720<p>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5721The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5722and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
5723intrinsic returns an i32 value that has the four bytes of the input i32
5724swapped, so that if the input bytes are numbered 0, 1, 2, 3 then the returned
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5725i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
5726<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5727additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5728</p>
5729
5730</div>
5731
5732<!-- _______________________________________________________________________ -->
5733<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5734 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5735</div>
5736
5737<div class="doc_text">
5738
5739<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5740<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5741width. Not all targets support all bit widths however.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5742<pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5743 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5744 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5745 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5746 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5747 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5748</pre>
5749
5750<h5>Overview:</h5>
5751
5752<p>
Chris Lattnerec6cb612006-01-16 22:38:59 +0000[diff] [blame]5753The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
5754value.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5755</p>
5756
5757<h5>Arguments:</h5>
5758
5759<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]5760The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5761integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5762</p>
5763
5764<h5>Semantics:</h5>
5765
5766<p>
5767The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
5768</p>
5769</div>
5770
5771<!-- _______________________________________________________________________ -->
5772<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5773 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5774</div>
5775
5776<div class="doc_text">
5777
5778<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5779<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5780integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5781<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5782 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5783 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5784 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5785 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5786 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5787</pre>
5788
5789<h5>Overview:</h5>
5790
5791<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5792The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5793leading zeros in a variable.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5794</p>
5795
5796<h5>Arguments:</h5>
5797
5798<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]5799The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5800integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5801</p>
5802
5803<h5>Semantics:</h5>
5804
5805<p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5806The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
5807in a variable. If the src == 0 then the result is the size in bits of the type
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5808of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5809</p>
5810</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5811
5812
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5813
5814<!-- _______________________________________________________________________ -->
5815<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5816 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5817</div>
5818
5819<div class="doc_text">
5820
5821<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5822<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5823integer bit width. Not all targets support all bit widths however.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5824<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5825 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5826 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5827 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5828 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5829 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5830</pre>
5831
5832<h5>Overview:</h5>
5833
5834<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5835The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5836trailing zeros.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5837</p>
5838
5839<h5>Arguments:</h5>
5840
5841<p>
5842The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5843integer type. The return type must match the argument type.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5844</p>
5845
5846<h5>Semantics:</h5>
5847
5848<p>
5849The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
5850in a variable. If the src == 0 then the result is the size in bits of the type
5851of src. For example, <tt>llvm.cttz(2) = 1</tt>.
5852</p>
5853</div>
5854
Reid Spencer497d93e2007-04-01 08:27:01 +0000[diff] [blame]5855<!-- _______________________________________________________________________ -->
5856<div class="doc_subsubsection">
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5857 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5858</div>
5859
5860<div class="doc_text">
5861
5862<h5>Syntax:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5863<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5864on any integer bit width.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5865<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5866 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
5867 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5868</pre>
5869
5870<h5>Overview:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5871<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5872range of bits from an integer value and returns them in the same bit width as
5873the original value.</p>
5874
5875<h5>Arguments:</h5>
5876<p>The first argument, <tt>%val</tt> and the result may be integer types of
5877any bit width but they must have the same bit width. The second and third
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5878arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5879
5880<h5>Semantics:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5881<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5882of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
5883<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
5884operates in forward mode.</p>
5885<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
5886right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5887only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
5888<ol>
5889 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
5890 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
5891 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
5892 to determine the number of bits to retain.</li>
5893 <li>A mask of the retained bits is created by shifting a -1 value.</li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5894 <li>The mask is ANDed with <tt>%val</tt> to produce the result.</li>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5895</ol>
Reid Spencerd6a85b52007-05-14 16:14:57 +0000[diff] [blame]5896<p>In reverse mode, a similar computation is made except that the bits are
5897returned in the reverse order. So, for example, if <tt>X</tt> has the value
5898<tt>i16 0x0ACF (101011001111)</tt> and we apply
5899<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
5900<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5901</div>
5902
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5903<div class="doc_subsubsection">
5904 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
5905</div>
5906
5907<div class="doc_text">
5908
5909<h5>Syntax:</h5>
5910<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5911on any integer bit width.</p>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5912<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5913 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
5914 declare i29 @llvm.part.set.i29.i9 (i29 %val, i9 %repl, i32 %lo, i32 %hi)
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5915</pre>
5916
5917<h5>Overview:</h5>
5918<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
5919of bits in an integer value with another integer value. It returns the integer
5920with the replaced bits.</p>
5921
5922<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5923<p>The first argument, <tt>%val</tt>, and the result may be integer types of
5924any bit width, but they must have the same bit width. <tt>%val</tt> is the value
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5925whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
5926integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
5927type since they specify only a bit index.</p>
5928
5929<h5>Semantics:</h5>
5930<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
5931of operation: forwards and reverse. If <tt>%lo</tt> is greater than
5932<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
5933operates in forward mode.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5934
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5935<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
5936truncating it down to the size of the replacement area or zero extending it
5937up to that size.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5938
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5939<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5940are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5941in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5942to the <tt>%hi</tt>th bit.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5943
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5944<p>In reverse mode, a similar computation is made except that the bits are
5945reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5946<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5947
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5948<h5>Examples:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5949
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5950<pre>
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5951 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5952 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5953 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5954 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5955 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]5956</pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5957
5958</div>
5959
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5960<!-- ======================================================================= -->
5961<div class="doc_subsection">
5962 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
5963</div>
5964
5965<div class="doc_text">
5966<p>
5967LLVM provides intrinsics for some arithmetic with overflow operations.
5968</p>
5969
5970</div>
5971
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5972<!-- _______________________________________________________________________ -->
5973<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5974 <a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5975</div>
5976
5977<div class="doc_text">
5978
5979<h5>Syntax:</h5>
5980
5981<p>This is an overloaded intrinsic. You can use <tt>llvm.sadd.with.overflow</tt>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5982on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5983
5984<pre>
5985 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
5986 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
5987 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
5988</pre>
5989
5990<h5>Overview:</h5>
5991
5992<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
5993a signed addition of the two arguments, and indicate whether an overflow
5994occurred during the signed summation.</p>
5995
5996<h5>Arguments:</h5>
5997
5998<p>The arguments (%a and %b) and the first element of the result structure may
5999be of integer types of any bit width, but they must have the same bit width. The
6000second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
6001and <tt>%b</tt> are the two values that will undergo signed addition.</p>
6002
6003<h5>Semantics:</h5>
6004
6005<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
6006a signed addition of the two variables. They return a structure &mdash; the
6007first element of which is the signed summation, and the second element of which
6008is a bit specifying if the signed summation resulted in an overflow.</p>
6009
6010<h5>Examples:</h5>
6011<pre>
6012 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6013 %sum = extractvalue {i32, i1} %res, 0
6014 %obit = extractvalue {i32, i1} %res, 1
6015 br i1 %obit, label %overflow, label %normal
6016</pre>
6017
6018</div>
6019
6020<!-- _______________________________________________________________________ -->
6021<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6022 <a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6023</div>
6024
6025<div class="doc_text">
6026
6027<h5>Syntax:</h5>
6028
6029<p>This is an overloaded intrinsic. You can use <tt>llvm.uadd.with.overflow</tt>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6030on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6031
6032<pre>
6033 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6034 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6035 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6036</pre>
6037
6038<h5>Overview:</h5>
6039
6040<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
6041an unsigned addition of the two arguments, and indicate whether a carry occurred
6042during the unsigned summation.</p>
6043
6044<h5>Arguments:</h5>
6045
6046<p>The arguments (%a and %b) and the first element of the result structure may
6047be of integer types of any bit width, but they must have the same bit width. The
6048second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
6049and <tt>%b</tt> are the two values that will undergo unsigned addition.</p>
6050
6051<h5>Semantics:</h5>
6052
6053<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
6054an unsigned addition of the two arguments. They return a structure &mdash; the
6055first element of which is the sum, and the second element of which is a bit
6056specifying if the unsigned summation resulted in a carry.</p>
6057
6058<h5>Examples:</h5>
6059<pre>
6060 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6061 %sum = extractvalue {i32, i1} %res, 0
6062 %obit = extractvalue {i32, i1} %res, 1
6063 br i1 %obit, label %carry, label %normal
6064</pre>
6065
6066</div>
6067
6068<!-- _______________________________________________________________________ -->
6069<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6070 <a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6071</div>
6072
6073<div class="doc_text">
6074
6075<h5>Syntax:</h5>
6076
6077<p>This is an overloaded intrinsic. You can use <tt>llvm.ssub.with.overflow</tt>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6078on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6079
6080<pre>
6081 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6082 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6083 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6084</pre>
6085
6086<h5>Overview:</h5>
6087
6088<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
6089a signed subtraction of the two arguments, and indicate whether an overflow
6090occurred during the signed subtraction.</p>
6091
6092<h5>Arguments:</h5>
6093
6094<p>The arguments (%a and %b) and the first element of the result structure may
6095be of integer types of any bit width, but they must have the same bit width. The
6096second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
6097and <tt>%b</tt> are the two values that will undergo signed subtraction.</p>
6098
6099<h5>Semantics:</h5>
6100
6101<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
6102a signed subtraction of the two arguments. They return a structure &mdash; the
6103first element of which is the subtraction, and the second element of which is a bit
6104specifying if the signed subtraction resulted in an overflow.</p>
6105
6106<h5>Examples:</h5>
6107<pre>
6108 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6109 %sum = extractvalue {i32, i1} %res, 0
6110 %obit = extractvalue {i32, i1} %res, 1
6111 br i1 %obit, label %overflow, label %normal
6112</pre>
6113
6114</div>
6115
6116<!-- _______________________________________________________________________ -->
6117<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6118 <a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6119</div>
6120
6121<div class="doc_text">
6122
6123<h5>Syntax:</h5>
6124
6125<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6126on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6127
6128<pre>
6129 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6130 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6131 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6132</pre>
6133
6134<h5>Overview:</h5>
6135
6136<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
6137an unsigned subtraction of the two arguments, and indicate whether an overflow
6138occurred during the unsigned subtraction.</p>
6139
6140<h5>Arguments:</h5>
6141
6142<p>The arguments (%a and %b) and the first element of the result structure may
6143be of integer types of any bit width, but they must have the same bit width. The
6144second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
6145and <tt>%b</tt> are the two values that will undergo unsigned subtraction.</p>
6146
6147<h5>Semantics:</h5>
6148
6149<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
6150an unsigned subtraction of the two arguments. They return a structure &mdash; the
6151first element of which is the subtraction, and the second element of which is a bit
6152specifying if the unsigned subtraction resulted in an overflow.</p>
6153
6154<h5>Examples:</h5>
6155<pre>
6156 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6157 %sum = extractvalue {i32, i1} %res, 0
6158 %obit = extractvalue {i32, i1} %res, 1
6159 br i1 %obit, label %overflow, label %normal
6160</pre>
6161
6162</div>
6163
6164<!-- _______________________________________________________________________ -->
6165<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6166 <a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6167</div>
6168
6169<div class="doc_text">
6170
6171<h5>Syntax:</h5>
6172
6173<p>This is an overloaded intrinsic. You can use <tt>llvm.smul.with.overflow</tt>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6174on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6175
6176<pre>
6177 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6178 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6179 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6180</pre>
6181
6182<h5>Overview:</h5>
6183
6184<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
6185a signed multiplication of the two arguments, and indicate whether an overflow
6186occurred during the signed multiplication.</p>
6187
6188<h5>Arguments:</h5>
6189
6190<p>The arguments (%a and %b) and the first element of the result structure may
6191be of integer types of any bit width, but they must have the same bit width. The
6192second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
6193and <tt>%b</tt> are the two values that will undergo signed multiplication.</p>
6194
6195<h5>Semantics:</h5>
6196
6197<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
6198a signed multiplication of the two arguments. They return a structure &mdash;
6199the first element of which is the multiplication, and the second element of
6200which is a bit specifying if the signed multiplication resulted in an
6201overflow.</p>
6202
6203<h5>Examples:</h5>
6204<pre>
6205 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6206 %sum = extractvalue {i32, i1} %res, 0
6207 %obit = extractvalue {i32, i1} %res, 1
6208 br i1 %obit, label %overflow, label %normal
6209</pre>
6210
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]6211</div>
6212
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6213<!-- _______________________________________________________________________ -->
6214<div class="doc_subsubsection">
6215 <a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
6216</div>
6217
6218<div class="doc_text">
6219
6220<h5>Syntax:</h5>
6221
6222<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
6223on any integer bit width.</p>
6224
6225<pre>
6226 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6227 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6228 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6229</pre>
6230
6231<h5>Overview:</h5>
6232
6233<p><i><b>Warning:</b> '<tt>llvm.umul.with.overflow</tt>' is badly broken. It is
6234actively being fixed, but it should not currently be used!</i></p>
6235
6236<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
6237a unsigned multiplication of the two arguments, and indicate whether an overflow
6238occurred during the unsigned multiplication.</p>
6239
6240<h5>Arguments:</h5>
6241
6242<p>The arguments (%a and %b) and the first element of the result structure may
6243be of integer types of any bit width, but they must have the same bit width. The
6244second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
6245and <tt>%b</tt> are the two values that will undergo unsigned
6246multiplication.</p>
6247
6248<h5>Semantics:</h5>
6249
6250<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
6251an unsigned multiplication of the two arguments. They return a structure &mdash;
6252the first element of which is the multiplication, and the second element of
6253which is a bit specifying if the unsigned multiplication resulted in an
6254overflow.</p>
6255
6256<h5>Examples:</h5>
6257<pre>
6258 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6259 %sum = extractvalue {i32, i1} %res, 0
6260 %obit = extractvalue {i32, i1} %res, 1
6261 br i1 %obit, label %overflow, label %normal
6262</pre>
6263
6264</div>
6265
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6266<!-- ======================================================================= -->
6267<div class="doc_subsection">
6268 <a name="int_debugger">Debugger Intrinsics</a>
6269</div>
6270
6271<div class="doc_text">
6272<p>
6273The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
6274are described in the <a
6275href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
6276Debugging</a> document.
6277</p>
6278</div>
6279
6280
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6281<!-- ======================================================================= -->
6282<div class="doc_subsection">
6283 <a name="int_eh">Exception Handling Intrinsics</a>
6284</div>
6285
6286<div class="doc_text">
6287<p> The LLVM exception handling intrinsics (which all start with
6288<tt>llvm.eh.</tt> prefix), are described in the <a
6289href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
6290Handling</a> document. </p>
6291</div>
6292
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6293<!-- ======================================================================= -->
6294<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6295 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6296</div>
6297
6298<div class="doc_text">
6299<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6300 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6301 the <tt>nest</tt> attribute, from a function. The result is a callable
6302 function pointer lacking the nest parameter - the caller does not need
6303 to provide a value for it. Instead, the value to use is stored in
6304 advance in a "trampoline", a block of memory usually allocated
6305 on the stack, which also contains code to splice the nest value into the
6306 argument list. This is used to implement the GCC nested function address
6307 extension.
6308</p>
6309<p>
6310 For example, if the function is
6311 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
Bill Wendling03295ca2007-09-22 09:23:55 +0000[diff] [blame]6312 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as follows:</p>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6313<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6314 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
6315 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
6316 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
6317 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6318</pre>
Bill Wendling03295ca2007-09-22 09:23:55 +0000[diff] [blame]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>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6321</div>
6322
6323<!-- _______________________________________________________________________ -->
6324<div class="doc_subsubsection">
6325 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
6326</div>
6327<div class="doc_text">
6328<h5>Syntax:</h5>
6329<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6330declare 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]6331</pre>
6332<h5>Overview:</h5>
6333<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6334 This fills the memory pointed to by <tt>tramp</tt> with code
6335 and returns a function pointer suitable for executing it.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6336</p>
6337<h5>Arguments:</h5>
6338<p>
6339 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
6340 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
6341 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsc00c2ba2007-08-22 23:39:54 +0000[diff] [blame]6342 intrinsic. Note that the size and the alignment are target-specific - LLVM
6343 currently provides no portable way of determining them, so a front-end that
6344 generates this intrinsic needs to have some target-specific knowledge.
6345 The <tt>func</tt> argument must hold a function bitcast to an <tt>i8*</tt>.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6346</p>
6347<h5>Semantics:</h5>
6348<p>
6349 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6350 dependent code, turning it into a function. A pointer to this function is
6351 returned, but needs to be bitcast to an
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6352 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6353 before being called. The new function's signature is the same as that of
6354 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
6355 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
6356 of pointer type. Calling the new function is equivalent to calling
6357 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
6358 missing <tt>nest</tt> argument. If, after calling
6359 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
6360 modified, then the effect of any later call to the returned function pointer is
6361 undefined.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6362</p>
6363</div>
6364
6365<!-- ======================================================================= -->
6366<div class="doc_subsection">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6367 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
6368</div>
6369
6370<div class="doc_text">
6371<p>
6372 These intrinsic functions expand the "universal IR" of LLVM to represent
6373 hardware constructs for atomic operations and memory synchronization. This
6374 provides an interface to the hardware, not an interface to the programmer. It
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]6375 is aimed at a low enough level to allow any programming models or APIs
6376 (Application Programming Interfaces) which
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6377 need atomic behaviors to map cleanly onto it. It is also modeled primarily on
6378 hardware behavior. Just as hardware provides a "universal IR" for source
6379 languages, it also provides a starting point for developing a "universal"
6380 atomic operation and synchronization IR.
6381</p>
6382<p>
6383 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.
6390
6391</p>
6392</div>
6393
6394<!-- _______________________________________________________________________ -->
6395<div class="doc_subsubsection">
6396 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
6397</div>
6398<div class="doc_text">
6399<h5>Syntax:</h5>
6400<pre>
6401declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;,
6402i1 &lt;device&gt; )
6403
6404</pre>
6405<h5>Overview:</h5>
6406<p>
6407 The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
6408 specific pairs of memory access types.
6409</p>
6410<h5>Arguments:</h5>
6411<p>
6412 The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
6413 The first four arguments enables a specific barrier as listed below. The fith
6414 argument specifies that the barrier applies to io or device or uncached memory.
6415
6416</p>
6417 <ul>
6418 <li><tt>ll</tt>: load-load barrier</li>
6419 <li><tt>ls</tt>: load-store barrier</li>
6420 <li><tt>sl</tt>: store-load barrier</li>
6421 <li><tt>ss</tt>: store-store barrier</li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6422 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6423 </ul>
6424<h5>Semantics:</h5>
6425<p>
6426 This intrinsic causes the system to enforce some ordering constraints upon
6427 the loads and stores of the program. This barrier does not indicate
6428 <em>when</em> any events will occur, it only enforces an <em>order</em> in
6429 which they occur. For any of the specified pairs of load and store operations
6430 (f.ex. load-load, or store-load), all of the first operations preceding the
6431 barrier will complete before any of the second operations succeeding the
6432 barrier begin. Specifically the semantics for each pairing is as follows:
6433</p>
6434 <ul>
6435 <li><tt>ll</tt>: All loads before the barrier must complete before any load
6436 after the barrier begins.</li>
6437
6438 <li><tt>ls</tt>: All loads before the barrier must complete before any
6439 store after the barrier begins.</li>
6440 <li><tt>ss</tt>: All stores before the barrier must complete before any
6441 store after the barrier begins.</li>
6442 <li><tt>sl</tt>: All stores before the barrier must complete before any
6443 load after the barrier begins.</li>
6444 </ul>
6445<p>
6446 These semantics are applied with a logical "and" behavior when more than one
6447 is enabled in a single memory barrier intrinsic.
6448</p>
6449<p>
6450 Backends may implement stronger barriers than those requested when they do not
6451 support as fine grained a barrier as requested. Some architectures do not
6452 need all types of barriers and on such architectures, these become noops.
6453</p>
6454<h5>Example:</h5>
6455<pre>
6456%ptr = malloc i32
6457 store i32 4, %ptr
6458
6459%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
6460 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
6461 <i>; guarantee the above finishes</i>
6462 store i32 8, %ptr <i>; before this begins</i>
6463</pre>
6464</div>
6465
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6466<!-- _______________________________________________________________________ -->
6467<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6468 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6469</div>
6470<div class="doc_text">
6471<h5>Syntax:</h5>
6472<p>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6473 This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
6474 any integer bit width and for different address spaces. Not all targets
6475 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6476
6477<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6478declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6479declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6480declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
6481declare 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]6482
6483</pre>
6484<h5>Overview:</h5>
6485<p>
6486 This loads a value in memory and compares it to a given value. If they are
6487 equal, it stores a new value into the memory.
6488</p>
6489<h5>Arguments:</h5>
6490<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6491 The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6492 well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
6493 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
6494 this integer type. While any bit width integer may be used, targets may only
6495 lower representations they support in hardware.
6496
6497</p>
6498<h5>Semantics:</h5>
6499<p>
6500 This entire intrinsic must be executed atomically. It first loads the value
6501 in memory pointed to by <tt>ptr</tt> and compares it with the value
6502 <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
6503 loaded value is yielded in all cases. This provides the equivalent of an
6504 atomic compare-and-swap operation within the SSA framework.
6505</p>
6506<h5>Examples:</h5>
6507
6508<pre>
6509%ptr = malloc i32
6510 store i32 4, %ptr
6511
6512%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6513%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6514 <i>; yields {i32}:result1 = 4</i>
6515%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6516%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6517
6518%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6519%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6520 <i>; yields {i32}:result2 = 8</i>
6521%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6522
6523%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6524</pre>
6525</div>
6526
6527<!-- _______________________________________________________________________ -->
6528<div class="doc_subsubsection">
6529 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6530</div>
6531<div class="doc_text">
6532<h5>Syntax:</h5>
6533
6534<p>
6535 This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6536 integer bit width. Not all targets support all bit widths however.</p>
6537<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6538declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6539declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6540declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6541declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6542
6543</pre>
6544<h5>Overview:</h5>
6545<p>
6546 This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6547 the value from memory. It then stores the value in <tt>val</tt> in the memory
6548 at <tt>ptr</tt>.
6549</p>
6550<h5>Arguments:</h5>
6551
6552<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6553 The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6554 <tt>val</tt> argument and the result must be integers of the same bit width.
6555 The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6556 integer type. The targets may only lower integer representations they
6557 support.
6558</p>
6559<h5>Semantics:</h5>
6560<p>
6561 This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6562 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6563 equivalent of an atomic swap operation within the SSA framework.
6564
6565</p>
6566<h5>Examples:</h5>
6567<pre>
6568%ptr = malloc i32
6569 store i32 4, %ptr
6570
6571%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6572%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6573 <i>; yields {i32}:result1 = 4</i>
6574%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6575%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6576
6577%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6578%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6579 <i>; yields {i32}:result2 = 8</i>
6580
6581%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6582%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6583</pre>
6584</div>
6585
6586<!-- _______________________________________________________________________ -->
6587<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6588 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6589
6590</div>
6591<div class="doc_text">
6592<h5>Syntax:</h5>
6593<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6594 This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on any
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6595 integer bit width. Not all targets support all bit widths however.</p>
6596<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6597declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6598declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6599declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6600declare 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]6601
6602</pre>
6603<h5>Overview:</h5>
6604<p>
6605 This intrinsic adds <tt>delta</tt> to the value stored in memory at
6606 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6607</p>
6608<h5>Arguments:</h5>
6609<p>
6610
6611 The intrinsic takes two arguments, the first a pointer to an integer value
6612 and the second an integer value. The result is also an integer value. These
6613 integer types can have any bit width, but they must all have the same bit
6614 width. The targets may only lower integer representations they support.
6615</p>
6616<h5>Semantics:</h5>
6617<p>
6618 This intrinsic does a series of operations atomically. It first loads the
6619 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6620 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6621</p>
6622
6623<h5>Examples:</h5>
6624<pre>
6625%ptr = malloc i32
6626 store i32 4, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6627%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6628 <i>; yields {i32}:result1 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6629%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6630 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6631%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6632 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6633%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6634</pre>
6635</div>
6636
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6637<!-- _______________________________________________________________________ -->
6638<div class="doc_subsubsection">
6639 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6640
6641</div>
6642<div class="doc_text">
6643<h5>Syntax:</h5>
6644<p>
6645 This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6646 any integer bit width and for different address spaces. Not all targets
6647 support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6648<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6649declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6650declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6651declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6652declare 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]6653
6654</pre>
6655<h5>Overview:</h5>
6656<p>
6657 This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6658 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6659</p>
6660<h5>Arguments:</h5>
6661<p>
6662
6663 The intrinsic takes two arguments, the first a pointer to an integer value
6664 and the second an integer value. The result is also an integer value. These
6665 integer types can have any bit width, but they must all have the same bit
6666 width. The targets may only lower integer representations they support.
6667</p>
6668<h5>Semantics:</h5>
6669<p>
6670 This intrinsic does a series of operations atomically. It first loads the
6671 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6672 result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6673</p>
6674
6675<h5>Examples:</h5>
6676<pre>
6677%ptr = malloc i32
6678 store i32 8, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6679%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6680 <i>; yields {i32}:result1 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6681%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6682 <i>; yields {i32}:result2 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6683%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6684 <i>; yields {i32}:result3 = 2</i>
6685%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6686</pre>
6687</div>
6688
6689<!-- _______________________________________________________________________ -->
6690<div class="doc_subsubsection">
6691 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6692 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6693 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6694 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
6695
6696</div>
6697<div class="doc_text">
6698<h5>Syntax:</h5>
6699<p>
6700 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
6701 <tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6702 <tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
6703 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6704<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6705declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6706declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6707declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6708declare 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]6709
6710</pre>
6711
6712<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6713declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6714declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6715declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6716declare 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]6717
6718</pre>
6719
6720<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6721declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6722declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6723declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6724declare 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]6725
6726</pre>
6727
6728<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6729declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6730declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6731declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6732declare 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]6733
6734</pre>
6735<h5>Overview:</h5>
6736<p>
6737 These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6738 the value stored in memory at <tt>ptr</tt>. It yields the original value
6739 at <tt>ptr</tt>.
6740</p>
6741<h5>Arguments:</h5>
6742<p>
6743
6744 These intrinsics take two arguments, the first a pointer to an integer value
6745 and the second an integer value. The result is also an integer value. These
6746 integer types can have any bit width, but they must all have the same bit
6747 width. The targets may only lower integer representations they support.
6748</p>
6749<h5>Semantics:</h5>
6750<p>
6751 These intrinsics does a series of operations atomically. They first load the
6752 value stored at <tt>ptr</tt>. They then do the bitwise operation
6753 <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
6754 value stored at <tt>ptr</tt>.
6755</p>
6756
6757<h5>Examples:</h5>
6758<pre>
6759%ptr = malloc i32
6760 store i32 0x0F0F, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6761%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6762 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6763%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6764 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6765%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6766 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6767%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6768 <i>; yields {i32}:result3 = FF</i>
6769%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6770</pre>
6771</div>
6772
6773
6774<!-- _______________________________________________________________________ -->
6775<div class="doc_subsubsection">
6776 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6777 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6778 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6779 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
6780
6781</div>
6782<div class="doc_text">
6783<h5>Syntax:</h5>
6784<p>
6785 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6786 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6787 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6788 address spaces. Not all targets
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6789 support all bit widths however.</p>
6790<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6791declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6792declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6793declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6794declare 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]6795
6796</pre>
6797
6798<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6799declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6800declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6801declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6802declare 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]6803
6804</pre>
6805
6806<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6807declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6808declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6809declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6810declare 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]6811
6812</pre>
6813
6814<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6815declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6816declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6817declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6818declare 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]6819
6820</pre>
6821<h5>Overview:</h5>
6822<p>
6823 These intrinsics takes the signed or unsigned minimum or maximum of
6824 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6825 original value at <tt>ptr</tt>.
6826</p>
6827<h5>Arguments:</h5>
6828<p>
6829
6830 These intrinsics take two arguments, the first a pointer to an integer value
6831 and the second an integer value. The result is also an integer value. These
6832 integer types can have any bit width, but they must all have the same bit
6833 width. The targets may only lower integer representations they support.
6834</p>
6835<h5>Semantics:</h5>
6836<p>
6837 These intrinsics does a series of operations atomically. They first load the
6838 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
6839 <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
6840 the original value stored at <tt>ptr</tt>.
6841</p>
6842
6843<h5>Examples:</h5>
6844<pre>
6845%ptr = malloc i32
6846 store i32 7, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6847%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6848 <i>; yields {i32}:result0 = 7</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6849%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6850 <i>; yields {i32}:result1 = -2</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6851%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6852 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6853%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6854 <i>; yields {i32}:result3 = 8</i>
6855%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6856</pre>
6857</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6858
6859<!-- ======================================================================= -->
6860<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6861 <a name="int_general">General Intrinsics</a>
6862</div>
6863
6864<div class="doc_text">
6865<p> This class of intrinsics is designed to be generic and has
6866no specific purpose. </p>
6867</div>
6868
6869<!-- _______________________________________________________________________ -->
6870<div class="doc_subsubsection">
6871 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6872</div>
6873
6874<div class="doc_text">
6875
6876<h5>Syntax:</h5>
6877<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]6878 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]6879</pre>
6880
6881<h5>Overview:</h5>
6882
6883<p>
6884The '<tt>llvm.var.annotation</tt>' intrinsic
6885</p>
6886
6887<h5>Arguments:</h5>
6888
6889<p>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]6890The first argument is a pointer to a value, the second is a pointer to a
6891global string, the third is a pointer to a global string which is the source
6892file name, and the last argument is the line number.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6893</p>
6894
6895<h5>Semantics:</h5>
6896
6897<p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6898This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6899This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6900annotations. These have no other defined use, they are ignored by code
6901generation and optimization.
6902</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6903</div>
6904
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6905<!-- _______________________________________________________________________ -->
6906<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]6907 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6908</div>
6909
6910<div class="doc_text">
6911
6912<h5>Syntax:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6913<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6914any integer bit width.
6915</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6916<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]6917 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6918 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6919 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6920 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6921 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]6922</pre>
6923
6924<h5>Overview:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6925
6926<p>
6927The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6928</p>
6929
6930<h5>Arguments:</h5>
6931
6932<p>
6933The first argument is an integer value (result of some expression),
6934the second is a pointer to a global string, the third is a pointer to a global
6935string which is the source file name, and the last argument is the line number.
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6936It returns the value of the first argument.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6937</p>
6938
6939<h5>Semantics:</h5>
6940
6941<p>
6942This intrinsic allows annotations to be put on arbitrary expressions
6943with arbitrary strings. This can be useful for special purpose optimizations
6944that want to look for these annotations. These have no other defined use, they
6945are ignored by code generation and optimization.
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6946</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6947</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6948
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6949<!-- _______________________________________________________________________ -->
6950<div class="doc_subsubsection">
6951 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6952</div>
6953
6954<div class="doc_text">
6955
6956<h5>Syntax:</h5>
6957<pre>
6958 declare void @llvm.trap()
6959</pre>
6960
6961<h5>Overview:</h5>
6962
6963<p>
6964The '<tt>llvm.trap</tt>' intrinsic
6965</p>
6966
6967<h5>Arguments:</h5>
6968
6969<p>
6970None
6971</p>
6972
6973<h5>Semantics:</h5>
6974
6975<p>
6976This intrinsics is lowered to the target dependent trap instruction. If the
6977target does not have a trap instruction, this intrinsic will be lowered to the
6978call of the abort() function.
6979</p>
6980</div>
6981
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6982<!-- _______________________________________________________________________ -->
6983<div class="doc_subsubsection">
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]6984 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6985</div>
6986<div class="doc_text">
6987<h5>Syntax:</h5>
6988<pre>
6989declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
6990
6991</pre>
6992<h5>Overview:</h5>
6993<p>
6994 The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
6995 it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
6996 it is placed on the stack before local variables.
6997</p>
6998<h5>Arguments:</h5>
6999<p>
7000 The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
7001 first argument is the value loaded from the stack guard
7002 <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
7003 has enough space to hold the value of the guard.
7004</p>
7005<h5>Semantics:</h5>
7006<p>
7007 This intrinsic causes the prologue/epilogue inserter to force the position of
7008 the <tt>AllocaInst</tt> stack slot to be before local variables on the
7009 stack. This is to ensure that if a local variable on the stack is overwritten,
7010 it will destroy the value of the guard. When the function exits, the guard on
7011 the stack is checked against the original guard. If they're different, then
7012 the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
7013</p>
7014</div>
7015
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]7016<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]7017<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]7018<address>
7019 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]7020 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]7021 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]7022 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]7023
7024 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]7025 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]7026 Last modified: $Date$
7027</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]7028
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]7029</body>
7030</html>