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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 452e2627dc1de4fb5a2b1c9ac999f1b3396f82c7 / . / 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>
64 <li><a href="#aggregateconstants">Aggregate Constants</a></li>
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>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]548 <dd>The semantics of this linkage follow the ELF object file model: the
549 symbol is weak until linked, if not linked, the symbol becomes null instead
550 of being an undefined reference.
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]551 </dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]552
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]553 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]554
555 <dd>If none of the above identifiers are used, the global is externally
556 visible, meaning that it participates in linkage and can be used to resolve
557 external symbol references.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]558 </dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]559</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]560
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]561 <p>
562 The next two types of linkage are targeted for Microsoft Windows platform
563 only. They are designed to support importing (exporting) symbols from (to)
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]564 DLLs (Dynamic Link Libraries).
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]565 </p>
566
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]567 <dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]568 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
569
570 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
571 or variable via a global pointer to a pointer that is set up by the DLL
572 exporting the symbol. On Microsoft Windows targets, the pointer name is
Dan Gohman79564122009-01-12 21:35:55 +0000[diff] [blame]573 formed by combining <code>__imp_</code> and the function or variable name.
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]574 </dd>
575
576 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
577
578 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
579 pointer to a pointer in a DLL, so that it can be referenced with the
580 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
Dan Gohman79564122009-01-12 21:35:55 +0000[diff] [blame]581 name is formed by combining <code>__imp_</code> and the function or variable
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]582 name.
583 </dd>
584
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]585</dl>
586
Dan Gohmanf0032762008-11-24 17:18:39 +0000[diff] [blame]587<p>For example, since the "<tt>.LC0</tt>"
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]588variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
589variable and was linked with this one, one of the two would be renamed,
590preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
591external (i.e., lacking any linkage declarations), they are accessible
Reid Spencerac8d2762007-01-05 00:59:10 +0000[diff] [blame]592outside of the current module.</p>
593<p>It is illegal for a function <i>declaration</i>
594to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]595or <tt>extern_weak</tt>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]596<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]597linkages.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]598</div>
599
600<!-- ======================================================================= -->
601<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]602 <a name="callingconv">Calling Conventions</a>
603</div>
604
605<div class="doc_text">
606
607<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
608and <a href="#i_invoke">invokes</a> can all have an optional calling convention
609specified for the call. The calling convention of any pair of dynamic
610caller/callee must match, or the behavior of the program is undefined. The
611following calling conventions are supported by LLVM, and more may be added in
612the future:</p>
613
614<dl>
615 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
616
617 <dd>This calling convention (the default if no other calling convention is
618 specified) matches the target C calling conventions. This calling convention
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]619 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencerc28d2bc2006-12-31 21:30:18 +0000[diff] [blame]620 prototype and implemented declaration of the function (as does normal C).
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]621 </dd>
622
623 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
624
625 <dd>This calling convention attempts to make calls as fast as possible
626 (e.g. by passing things in registers). This calling convention allows the
627 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]628 without having to conform to an externally specified ABI (Application Binary
629 Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer9097d142008-05-14 09:17:12 +0000[diff] [blame]630 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
631 supported. This calling convention does not support varargs and requires the
632 prototype of all callees to exactly match the prototype of the function
633 definition.
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]634 </dd>
635
636 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
637
638 <dd>This calling convention attempts to make code in the caller as efficient
639 as possible under the assumption that the call is not commonly executed. As
640 such, these calls often preserve all registers so that the call does not break
641 any live ranges in the caller side. This calling convention does not support
642 varargs and requires the prototype of all callees to exactly match the
643 prototype of the function definition.
644 </dd>
645
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]646 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]647
648 <dd>Any calling convention may be specified by number, allowing
649 target-specific calling conventions to be used. Target specific calling
650 conventions start at 64.
651 </dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]652</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]653
654<p>More calling conventions can be added/defined on an as-needed basis, to
655support pascal conventions or any other well-known target-independent
656convention.</p>
657
658</div>
659
660<!-- ======================================================================= -->
661<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]662 <a name="visibility">Visibility Styles</a>
663</div>
664
665<div class="doc_text">
666
667<p>
668All Global Variables and Functions have one of the following visibility styles:
669</p>
670
671<dl>
672 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
673
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]674 <dd>On targets that use the ELF object file format, default visibility means
675 that the declaration is visible to other
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]676 modules and, in shared libraries, means that the declared entity may be
677 overridden. On Darwin, default visibility means that the declaration is
678 visible to other modules. Default visibility corresponds to "external
679 linkage" in the language.
680 </dd>
681
682 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
683
684 <dd>Two declarations of an object with hidden visibility refer to the same
685 object if they are in the same shared object. Usually, hidden visibility
686 indicates that the symbol will not be placed into the dynamic symbol table,
687 so no other module (executable or shared library) can reference it
688 directly.
689 </dd>
690
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]691 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
692
693 <dd>On ELF, protected visibility indicates that the symbol will be placed in
694 the dynamic symbol table, but that references within the defining module will
695 bind to the local symbol. That is, the symbol cannot be overridden by another
696 module.
697 </dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]698</dl>
699
700</div>
701
702<!-- ======================================================================= -->
703<div class="doc_subsection">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]704 <a name="namedtypes">Named Types</a>
705</div>
706
707<div class="doc_text">
708
709<p>LLVM IR allows you to specify name aliases for certain types. This can make
710it easier to read the IR and make the IR more condensed (particularly when
711recursive types are involved). An example of a name specification is:
712</p>
713
714<div class="doc_code">
715<pre>
716%mytype = type { %mytype*, i32 }
717</pre>
718</div>
719
720<p>You may give a name to any <a href="#typesystem">type</a> except "<a
721href="t_void">void</a>". Type name aliases may be used anywhere a type is
722expected with the syntax "%mytype".</p>
723
724<p>Note that type names are aliases for the structural type that they indicate,
725and that you can therefore specify multiple names for the same type. This often
726leads to confusing behavior when dumping out a .ll file. Since LLVM IR uses
727structural typing, the name is not part of the type. When printing out LLVM IR,
728the printer will pick <em>one name</em> to render all types of a particular
729shape. This means that if you have code where two different source types end up
730having the same LLVM type, that the dumper will sometimes print the "wrong" or
731unexpected type. This is an important design point and isn't going to
732change.</p>
733
734</div>
735
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]736<!-- ======================================================================= -->
737<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]738 <a name="globalvars">Global Variables</a>
739</div>
740
741<div class="doc_text">
742
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]743<p>Global variables define regions of memory allocated at compilation time
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]744instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]745an explicit section to be placed in, and may have an optional explicit alignment
746specified. A variable may be defined as "thread_local", which means that it
747will not be shared by threads (each thread will have a separated copy of the
748variable). A variable may be defined as a global "constant," which indicates
749that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]750optimization, allowing the global data to be placed in the read-only section of
751an executable, etc). Note that variables that need runtime initialization
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]752cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]753
754<p>
755LLVM explicitly allows <em>declarations</em> of global variables to be marked
756constant, even if the final definition of the global is not. This capability
757can be used to enable slightly better optimization of the program, but requires
758the language definition to guarantee that optimizations based on the
759'constantness' are valid for the translation units that do not include the
760definition.
761</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]762
763<p>As SSA values, global variables define pointer values that are in
764scope (i.e. they dominate) all basic blocks in the program. Global
765variables always define a pointer to their "content" type because they
766describe a region of memory, and all memory objects in LLVM are
767accessed through pointers.</p>
768
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]769<p>A global variable may be declared to reside in a target-specifc numbered
770address space. For targets that support them, address spaces may affect how
771optimizations are performed and/or what target instructions are used to access
Christopher Lambd49e18d2007-12-12 08:44:39 +0000[diff] [blame]772the variable. The default address space is zero. The address space qualifier
773must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]774
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]775<p>LLVM allows an explicit section to be specified for globals. If the target
776supports it, it will emit globals to the section specified.</p>
777
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]778<p>An explicit alignment may be specified for a global. If not present, or if
779the alignment is set to zero, the alignment of the global is set by the target
780to whatever it feels convenient. If an explicit alignment is specified, the
781global is forced to have at least that much alignment. All alignments must be
782a power of 2.</p>
783
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]784<p>For example, the following defines a global in a numbered address space with
785an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]786
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]787<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]788<pre>
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]789@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]790</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]791</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]792
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]793</div>
794
795
796<!-- ======================================================================= -->
797<div class="doc_subsection">
798 <a name="functionstructure">Functions</a>
799</div>
800
801<div class="doc_text">
802
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]803<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
804an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]805<a href="#visibility">visibility style</a>, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]806<a href="#callingconv">calling convention</a>, a return type, an optional
807<a href="#paramattrs">parameter attribute</a> for the return type, a function
808name, a (possibly empty) argument list (each with optional
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]809<a href="#paramattrs">parameter attributes</a>), optional
810<a href="#fnattrs">function attributes</a>, an optional section,
811an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner0c46a7d2008-10-04 18:10:21 +0000[diff] [blame]812an opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]813
814LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
815optional <a href="#linkage">linkage type</a>, an optional
816<a href="#visibility">visibility style</a>, an optional
817<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]818<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]819name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksene754abe2007-12-10 03:30:21 +0000[diff] [blame]820<a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]821
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]822<p>A function definition contains a list of basic blocks, forming the CFG
823(Control Flow Graph) for
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]824the function. Each basic block may optionally start with a label (giving the
825basic block a symbol table entry), contains a list of instructions, and ends
826with a <a href="#terminators">terminator</a> instruction (such as a branch or
827function return).</p>
828
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]829<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]830executed on entrance to the function, and it is not allowed to have predecessor
831basic blocks (i.e. there can not be any branches to the entry block of a
832function). Because the block can have no predecessors, it also cannot have any
833<a href="#i_phi">PHI nodes</a>.</p>
834
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]835<p>LLVM allows an explicit section to be specified for functions. If the target
836supports it, it will emit functions to the section specified.</p>
837
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]838<p>An explicit alignment may be specified for a function. If not present, or if
839the alignment is set to zero, the alignment of the function is set by the target
840to whatever it feels convenient. If an explicit alignment is specified, the
841function is forced to have at least that much alignment. All alignments must be
842a power of 2.</p>
843
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]844 <h5>Syntax:</h5>
845
846<div class="doc_code">
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]847<tt>
848define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
849 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
850 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
851 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
852 [<a href="#gc">gc</a>] { ... }
853</tt>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]854</div>
855
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]856</div>
857
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]858
859<!-- ======================================================================= -->
860<div class="doc_subsection">
861 <a name="aliasstructure">Aliases</a>
862</div>
863<div class="doc_text">
864 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov726d45c2008-03-22 08:36:14 +0000[diff] [blame]865 function, global variable, another alias or bitcast of global value). Aliases
866 may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]867 optional <a href="#visibility">visibility style</a>.</p>
868
869 <h5>Syntax:</h5>
870
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]871<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]872<pre>
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]873@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]874</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]875</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]876
877</div>
878
879
880
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]881<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]882<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
883<div class="doc_text">
884 <p>The return type and each parameter of a function type may have a set of
885 <i>parameter attributes</i> associated with them. Parameter attributes are
886 used to communicate additional information about the result or parameters of
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]887 a function. Parameter attributes are considered to be part of the function,
888 not of the function type, so functions with different parameter attributes
889 can have the same function type.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]890
Reid Spencer950e9f82007-01-15 18:27:39 +0000[diff] [blame]891 <p>Parameter attributes are simple keywords that follow the type specified. If
892 multiple parameter attributes are needed, they are space separated. For
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]893 example:</p>
894
895<div class="doc_code">
896<pre>
Nick Lewyckyb6a7d252009-02-15 23:06:14 +0000[diff] [blame]897declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]898declare i32 @atoi(i8 zeroext)
899declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]900</pre>
901</div>
902
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]903 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
904 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]905
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]906 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]907 <dl>
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]908 <dt><tt>zeroext</tt></dt>
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]909 <dd>This indicates to the code generator that the parameter or return value
910 should be zero-extended to a 32-bit value by the caller (for a parameter)
911 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]912
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]913 <dt><tt>signext</tt></dt>
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]914 <dd>This indicates to the code generator that the parameter or return value
915 should be sign-extended to a 32-bit value by the caller (for a parameter)
916 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]917
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]918 <dt><tt>inreg</tt></dt>
Dale Johannesenc9c6da62008-09-25 20:47:45 +0000[diff] [blame]919 <dd>This indicates that this parameter or return value should be treated
920 in a special target-dependent fashion during while emitting code for a
921 function call or return (usually, by putting it in a register as opposed
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]922 to memory, though some targets use it to distinguish between two different
923 kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]924
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]925 <dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner0747baa2008-01-15 04:34:22 +0000[diff] [blame]926 <dd>This indicates that the pointer parameter should really be passed by
927 value to the function. The attribute implies that a hidden copy of the
928 pointee is made between the caller and the callee, so the callee is unable
Chris Lattnerebec6782008-08-05 18:21:08 +0000[diff] [blame]929 to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner0747baa2008-01-15 04:34:22 +0000[diff] [blame]930 pointer arguments. It is generally used to pass structs and arrays by
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]931 value, but is also valid on pointers to scalars. The copy is considered to
932 belong to the caller not the callee (for example,
933 <tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]934 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattnerce459b12009-02-05 05:42:28 +0000[diff] [blame]935 values. The byval attribute also supports specifying an alignment with the
936 align attribute. This has a target-specific effect on the code generator
937 that usually indicates a desired alignment for the synthesized stack
938 slot.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]939
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]940 <dt><tt>sret</tt></dt>
Duncan Sandse26dec62008-02-18 04:19:38 +0000[diff] [blame]941 <dd>This indicates that the pointer parameter specifies the address of a
942 structure that is the return value of the function in the source program.
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]943 This pointer must be guaranteed by the caller to be valid: loads and stores
944 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]945 be applied to the first parameter. This is not a valid attribute for
946 return values. </dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]947
Zhou Shengfebca342007-06-05 05:28:26 +0000[diff] [blame]948 <dt><tt>noalias</tt></dt>
Nick Lewycky02ff3082008-11-24 03:41:24 +0000[diff] [blame]949 <dd>This indicates that the pointer does not alias any global or any other
950 parameter. The caller is responsible for ensuring that this is the
Nick Lewyckyb2b32fd2008-11-24 05:00:44 +0000[diff] [blame]951 case. On a function return value, <tt>noalias</tt> additionally indicates
952 that the pointer does not alias any other pointers visible to the
Nick Lewyckyf23d0d32008-12-19 06:39:12 +0000[diff] [blame]953 caller. For further details, please see the discussion of the NoAlias
954 response in
955 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
956 analysis</a>.</dd>
957
958 <dt><tt>nocapture</tt></dt>
959 <dd>This indicates that the callee does not make any copies of the pointer
960 that outlive the callee itself. This is not a valid attribute for return
961 values.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]962
Duncan Sands50f19f52007-07-27 19:57:41 +0000[diff] [blame]963 <dt><tt>nest</tt></dt>
Duncan Sands0789b8b2008-07-08 09:27:25 +0000[diff] [blame]964 <dd>This indicates that the pointer parameter can be excised using the
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]965 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
966 attribute for return values.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]967 </dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]968
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]969</div>
970
971<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]972<div class="doc_subsection">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]973 <a name="gc">Garbage Collector Names</a>
974</div>
975
976<div class="doc_text">
977<p>Each function may specify a garbage collector name, which is simply a
978string.</p>
979
980<div class="doc_code"><pre
981>define void @f() gc "name" { ...</pre></div>
982
983<p>The compiler declares the supported values of <i>name</i>. Specifying a
984collector which will cause the compiler to alter its output in order to support
985the named garbage collection algorithm.</p>
986</div>
987
988<!-- ======================================================================= -->
989<div class="doc_subsection">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]990 <a name="fnattrs">Function Attributes</a>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]991</div>
992
993<div class="doc_text">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]994
995<p>Function attributes are set to communicate additional information about
996 a function. Function attributes are considered to be part of the function,
997 not of the function type, so functions with different parameter attributes
998 can have the same function type.</p>
999
1000 <p>Function attributes are simple keywords that follow the type specified. If
1001 multiple attributes are needed, they are space separated. For
1002 example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1003
1004<div class="doc_code">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1005<pre>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1006define void @f() noinline { ... }
1007define void @f() alwaysinline { ... }
1008define void @f() alwaysinline optsize { ... }
1009define void @f() optsize
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1010</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1011</div>
1012
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1013<dl>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1014<dt><tt>alwaysinline</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1015<dd>This attribute indicates that the inliner should attempt to inline this
1016function into callers whenever possible, ignoring any active inlining size
1017threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1018
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1019<dt><tt>noinline</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1020<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner94b5f7d2008-10-05 17:14:59 +0000[diff] [blame]1021in any situation. This attribute may not be used together with the
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1022<tt>alwaysinline</tt> attribute.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1023
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1024<dt><tt>optsize</tt></dt>
Devang Patel66c6c652008-09-29 18:34:44 +0000[diff] [blame]1025<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1026make choices that keep the code size of this function low, and otherwise do
1027optimizations specifically to reduce code size.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1028
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1029<dt><tt>noreturn</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1030<dd>This function attribute indicates that the function never returns normally.
1031This produces undefined behavior at runtime if the function ever does
1032dynamically return.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1033
1034<dt><tt>nounwind</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1035<dd>This function attribute indicates that the function never returns with an
1036unwind or exceptional control flow. If the function does unwind, its runtime
1037behavior is undefined.</dd>
1038
1039<dt><tt>readnone</tt></dt>
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]1040<dd>This attribute indicates that the function computes its result (or the
1041exception it throws) based strictly on its arguments, without dereferencing any
1042pointer arguments or otherwise accessing any mutable state (e.g. memory, control
1043registers, etc) visible to caller functions. It does not write through any
1044pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
1045never changes any state visible to callers.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1046
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]1047<dt><tt><a name="readonly">readonly</a></tt></dt>
1048<dd>This attribute indicates that the function does not write through any
1049pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
1050or otherwise modify any state (e.g. memory, control registers, etc) visible to
1051caller functions. It may dereference pointer arguments and read state that may
1052be set in the caller. A readonly function always returns the same value (or
1053throws the same exception) when called with the same set of arguments and global
1054state.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1055
1056<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1057<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1058protector. It is in the form of a "canary"&mdash;a random value placed on the
1059stack before the local variables that's checked upon return from the function to
1060see if it has been overwritten. A heuristic is used to determine if a function
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1061needs stack protectors or not.
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1062
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1063<p>If a function that has an <tt>ssp</tt> attribute is inlined into a function
1064that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
1065have an <tt>ssp</tt> attribute.</p></dd>
1066
1067<dt><tt>sspreq</tt></dt>
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1068<dd>This attribute indicates that the function should <em>always</em> emit a
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1069stack smashing protector. This overrides the <tt><a href="#ssp">ssp</a></tt>
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1070function attribute.
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1071
1072<p>If a function that has an <tt>sspreq</tt> attribute is inlined into a
1073function that doesn't have an <tt>sspreq</tt> attribute or which has
1074an <tt>ssp</tt> attribute, then the resulting function will have
1075an <tt>sspreq</tt> attribute.</p></dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1076</dl>
1077
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1078</div>
1079
1080<!-- ======================================================================= -->
1081<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1082 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1083</div>
1084
1085<div class="doc_text">
1086<p>
1087Modules may contain "module-level inline asm" blocks, which corresponds to the
1088GCC "file scope inline asm" blocks. These blocks are internally concatenated by
1089LLVM and treated as a single unit, but may be separated in the .ll file if
1090desired. The syntax is very simple:
1091</p>
1092
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1093<div class="doc_code">
1094<pre>
1095module asm "inline asm code goes here"
1096module asm "more can go here"
1097</pre>
1098</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1099
1100<p>The strings can contain any character by escaping non-printable characters.
1101 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
1102 for the number.
1103</p>
1104
1105<p>
1106 The inline asm code is simply printed to the machine code .s file when
1107 assembly code is generated.
1108</p>
1109</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1110
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1111<!-- ======================================================================= -->
1112<div class="doc_subsection">
1113 <a name="datalayout">Data Layout</a>
1114</div>
1115
1116<div class="doc_text">
1117<p>A module may specify a target specific data layout string that specifies how
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]1118data is to be laid out in memory. The syntax for the data layout is simply:</p>
1119<pre> target datalayout = "<i>layout specification</i>"</pre>
1120<p>The <i>layout specification</i> consists of a list of specifications
1121separated by the minus sign character ('-'). Each specification starts with a
1122letter and may include other information after the letter to define some
1123aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1124<dl>
1125 <dt><tt>E</tt></dt>
1126 <dd>Specifies that the target lays out data in big-endian form. That is, the
1127 bits with the most significance have the lowest address location.</dd>
1128 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1129 <dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1130 the bits with the least significance have the lowest address location.</dd>
1131 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1132 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
1133 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
1134 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
1135 too.</dd>
1136 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1137 <dd>This specifies the alignment for an integer type of a given bit
1138 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1139 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1140 <dd>This specifies the alignment for a vector type of a given bit
1141 <i>size</i>.</dd>
1142 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1143 <dd>This specifies the alignment for a floating point type of a given bit
1144 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1145 (double).</dd>
1146 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1147 <dd>This specifies the alignment for an aggregate type of a given bit
1148 <i>size</i>.</dd>
1149</dl>
1150<p>When constructing the data layout for a given target, LLVM starts with a
1151default set of specifications which are then (possibly) overriden by the
1152specifications in the <tt>datalayout</tt> keyword. The default specifications
1153are given in this list:</p>
1154<ul>
1155 <li><tt>E</tt> - big endian</li>
1156 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1157 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1158 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1159 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1160 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1161 <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]1162 alignment of 64-bits</li>
1163 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1164 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1165 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1166 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1167 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
1168</ul>
Chris Lattnerebec6782008-08-05 18:21:08 +0000[diff] [blame]1169<p>When LLVM is determining the alignment for a given type, it uses the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1170following rules:</p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1171<ol>
1172 <li>If the type sought is an exact match for one of the specifications, that
1173 specification is used.</li>
1174 <li>If no match is found, and the type sought is an integer type, then the
1175 smallest integer type that is larger than the bitwidth of the sought type is
1176 used. If none of the specifications are larger than the bitwidth then the the
1177 largest integer type is used. For example, given the default specifications
1178 above, the i7 type will use the alignment of i8 (next largest) while both
1179 i65 and i256 will use the alignment of i64 (largest specified).</li>
1180 <li>If no match is found, and the type sought is a vector type, then the
1181 largest vector type that is smaller than the sought vector type will be used
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1182 as a fall back. This happens because &lt;128 x double&gt; can be implemented
1183 in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1184</ol>
1185</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1186
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1187<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1188<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1189<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1190
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1191<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1192
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1193<p>The LLVM type system is one of the most important features of the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1194intermediate representation. Being typed enables a number of
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1195optimizations to be performed on the intermediate representation directly,
1196without having to do
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1197extra analyses on the side before the transformation. A strong type
1198system makes it easier to read the generated code and enables novel
1199analyses and transformations that are not feasible to perform on normal
1200three address code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1201
1202</div>
1203
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1204<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1205<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1206Classifications</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1207<div class="doc_text">
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1208<p>The types fall into a few useful
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1209classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1210
1211<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1212 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1213 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1214 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1215 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1216 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1217 </tr>
1218 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1219 <td><a href="#t_floating">floating point</a></td>
1220 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1221 </tr>
1222 <tr>
1223 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1224 <td><a href="#t_integer">integer</a>,
1225 <a href="#t_floating">floating point</a>,
1226 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1227 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1228 <a href="#t_struct">structure</a>,
1229 <a href="#t_array">array</a>,
Dan Gohmanade5faa2008-05-23 22:50:26 +0000[diff] [blame]1230 <a href="#t_label">label</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1231 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1232 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1233 <tr>
1234 <td><a href="#t_primitive">primitive</a></td>
1235 <td><a href="#t_label">label</a>,
1236 <a href="#t_void">void</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1237 <a href="#t_floating">floating point</a>.</td>
1238 </tr>
1239 <tr>
1240 <td><a href="#t_derived">derived</a></td>
1241 <td><a href="#t_integer">integer</a>,
1242 <a href="#t_array">array</a>,
1243 <a href="#t_function">function</a>,
1244 <a href="#t_pointer">pointer</a>,
1245 <a href="#t_struct">structure</a>,
1246 <a href="#t_pstruct">packed structure</a>,
1247 <a href="#t_vector">vector</a>,
1248 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1249 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1250 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1251 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1252</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1253
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1254<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1255most important. Values of these types are the only ones which can be
1256produced by instructions, passed as arguments, or used as operands to
Dan Gohmanc4b49eb2008-05-23 21:53:15 +0000[diff] [blame]1257instructions.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1258</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1259
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1260<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1261<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1262
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1263<div class="doc_text">
1264<p>The primitive types are the fundamental building blocks of the LLVM
1265system.</p>
1266
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1267</div>
1268
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1269<!-- _______________________________________________________________________ -->
1270<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1271
1272<div class="doc_text">
1273 <table>
1274 <tbody>
1275 <tr><th>Type</th><th>Description</th></tr>
1276 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1277 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1278 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1279 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1280 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1281 </tbody>
1282 </table>
1283</div>
1284
1285<!-- _______________________________________________________________________ -->
1286<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1287
1288<div class="doc_text">
1289<h5>Overview:</h5>
1290<p>The void type does not represent any value and has no size.</p>
1291
1292<h5>Syntax:</h5>
1293
1294<pre>
1295 void
1296</pre>
1297</div>
1298
1299<!-- _______________________________________________________________________ -->
1300<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1301
1302<div class="doc_text">
1303<h5>Overview:</h5>
1304<p>The label type represents code labels.</p>
1305
1306<h5>Syntax:</h5>
1307
1308<pre>
1309 label
1310</pre>
1311</div>
1312
1313
1314<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1315<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1316
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1317<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1318
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1319<p>The real power in LLVM comes from the derived types in the system.
1320This is what allows a programmer to represent arrays, functions,
1321pointers, and other useful types. Note that these derived types may be
1322recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1323
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1324</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1325
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1326<!-- _______________________________________________________________________ -->
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1327<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1328
1329<div class="doc_text">
1330
1331<h5>Overview:</h5>
1332<p>The integer type is a very simple derived type that simply specifies an
1333arbitrary bit width for the integer type desired. Any bit width from 1 bit to
13342^23-1 (about 8 million) can be specified.</p>
1335
1336<h5>Syntax:</h5>
1337
1338<pre>
1339 iN
1340</pre>
1341
1342<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1343value.</p>
1344
1345<h5>Examples:</h5>
1346<table class="layout">
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]1347 <tbody>
1348 <tr>
1349 <td><tt>i1</tt></td>
1350 <td>a single-bit integer.</td>
1351 </tr><tr>
1352 <td><tt>i32</tt></td>
1353 <td>a 32-bit integer.</td>
1354 </tr><tr>
1355 <td><tt>i1942652</tt></td>
1356 <td>a really big integer of over 1 million bits.</td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1357 </tr>
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]1358 </tbody>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1359</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1360
1361<p>Note that the code generator does not yet support large integer types
1362to be used as function return types. The specific limit on how large a
1363return type the code generator can currently handle is target-dependent;
1364currently it's often 64 bits for 32-bit targets and 128 bits for 64-bit
1365targets.</p>
1366
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1367</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1368
1369<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1370<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1371
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1372<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1373
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1374<h5>Overview:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1375
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1376<p>The array type is a very simple derived type that arranges elements
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1377sequentially in memory. The array type requires a size (number of
1378elements) and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1379
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1380<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1381
1382<pre>
1383 [&lt;# elements&gt; x &lt;elementtype&gt;]
1384</pre>
1385
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1386<p>The number of elements is a constant integer value; elementtype may
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1387be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1388
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1389<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1390<table class="layout">
1391 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1392 <td class="left"><tt>[40 x i32]</tt></td>
1393 <td class="left">Array of 40 32-bit integer values.</td>
1394 </tr>
1395 <tr class="layout">
1396 <td class="left"><tt>[41 x i32]</tt></td>
1397 <td class="left">Array of 41 32-bit integer values.</td>
1398 </tr>
1399 <tr class="layout">
1400 <td class="left"><tt>[4 x i8]</tt></td>
1401 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1402 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1403</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1404<p>Here are some examples of multidimensional arrays:</p>
1405<table class="layout">
1406 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1407 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1408 <td class="left">3x4 array of 32-bit integer values.</td>
1409 </tr>
1410 <tr class="layout">
1411 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1412 <td class="left">12x10 array of single precision floating point values.</td>
1413 </tr>
1414 <tr class="layout">
1415 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1416 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1417 </tr>
1418</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1419
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1420<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1421length array. Normally, accesses past the end of an array are undefined in
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1422LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1423As a special case, however, zero length arrays are recognized to be variable
1424length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1425type "{ i32, [0 x float]}", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1426
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1427<p>Note that the code generator does not yet support large aggregate types
1428to be used as function return types. The specific limit on how large an
1429aggregate return type the code generator can currently handle is
1430target-dependent, and also dependent on the aggregate element types.</p>
1431
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1432</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1433
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1434<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1435<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1436<div class="doc_text">
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1437
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1438<h5>Overview:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1439
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1440<p>The function type can be thought of as a function signature. It
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1441consists of a return type and a list of formal parameter types. The
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1442return 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]1443If 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]1444class types, and the struct must have at least one element.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1445
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1446<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1447
1448<pre>
1449 &lt;returntype list&gt; (&lt;parameter list&gt;)
1450</pre>
1451
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1452<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]1453specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1454which indicates that the function takes a variable number of arguments.
1455Variable argument functions can access their arguments with the <a
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1456 href="#int_varargs">variable argument handling intrinsic</a> functions.
1457'<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1458<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1459
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1460<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1461<table class="layout">
1462 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1463 <td class="left"><tt>i32 (i32)</tt></td>
1464 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1465 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1466 </tr><tr class="layout">
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]1467 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1468 </tt></td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1469 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1470 an <tt>i16</tt> that should be sign extended and a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1471 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1472 <tt>float</tt>.
1473 </td>
1474 </tr><tr class="layout">
1475 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1476 <td class="left">A vararg function that takes at least one
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1477 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1478 which returns an integer. This is the signature for <tt>printf</tt> in
1479 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1480 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1481 </tr><tr class="layout">
1482 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukmanb0a57aa2008-11-27 06:41:20 +0000[diff] [blame]1483 <td class="left">A function taking an <tt>i32</tt>, returning two
1484 <tt>i32</tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1485 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1486 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1487</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1488
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1489</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1490<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1491<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1492<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1493<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1494<p>The structure type is used to represent a collection of data members
1495together in memory. The packing of the field types is defined to match
1496the ABI of the underlying processor. The elements of a structure may
1497be any type that has a size.</p>
1498<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1499and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1500field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1501instruction.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1502<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1503<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1504<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1505<table class="layout">
1506 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1507 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1508 <td class="left">A triple of three <tt>i32</tt> values</td>
1509 </tr><tr class="layout">
1510 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1511 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1512 second element is a <a href="#t_pointer">pointer</a> to a
1513 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1514 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1515 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1516</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1517
1518<p>Note that the code generator does not yet support large aggregate types
1519to be used as function return types. The specific limit on how large an
1520aggregate return type the code generator can currently handle is
1521target-dependent, and also dependent on the aggregate element types.</p>
1522
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1523</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1524
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1525<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1526<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1527</div>
1528<div class="doc_text">
1529<h5>Overview:</h5>
1530<p>The packed structure type is used to represent a collection of data members
1531together in memory. There is no padding between fields. Further, the alignment
1532of a packed structure is 1 byte. The elements of a packed structure may
1533be any type that has a size.</p>
1534<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1535and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1536field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1537instruction.</p>
1538<h5>Syntax:</h5>
1539<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1540<h5>Examples:</h5>
1541<table class="layout">
1542 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1543 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1544 <td class="left">A triple of three <tt>i32</tt> values</td>
1545 </tr><tr class="layout">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1546 <td class="left">
1547<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1548 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1549 second element is a <a href="#t_pointer">pointer</a> to a
1550 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1551 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1552 </tr>
1553</table>
1554</div>
1555
1556<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1557<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1558<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1559<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1560<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]1561reference to another object, which must live in memory. Pointer types may have
1562an optional address space attribute defining the target-specific numbered
1563address space where the pointed-to object resides. The default address space is
1564zero.</p>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1565
1566<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]1567it permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1568
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1569<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1570<pre> &lt;type&gt; *<br></pre>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1571<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1572<table class="layout">
1573 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]1574 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1575 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1576 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1577 </tr>
1578 <tr class="layout">
1579 <td class="left"><tt>i32 (i32 *) *</tt></td>
1580 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1581 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1582 <tt>i32</tt>.</td>
1583 </tr>
1584 <tr class="layout">
1585 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1586 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1587 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1588 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1589</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1590</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1591
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1592<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1593<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1594<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1595
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1596<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1597
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1598<p>A vector type is a simple derived type that represents a vector
1599of elements. Vector types are used when multiple primitive data
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1600are operated in parallel using a single instruction (SIMD).
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1601A vector type requires a size (number of
Chris Lattnerb8d172f2005-11-10 01:44:22 +0000[diff] [blame]1602elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1603of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1604considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1605
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1606<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1607
1608<pre>
1609 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1610</pre>
1611
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1612<p>The number of elements is a constant integer value; elementtype may
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1613be any integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1614
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1615<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1616
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1617<table class="layout">
1618 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1619 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1620 <td class="left">Vector of 4 32-bit integer values.</td>
1621 </tr>
1622 <tr class="layout">
1623 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1624 <td class="left">Vector of 8 32-bit floating-point values.</td>
1625 </tr>
1626 <tr class="layout">
1627 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1628 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1629 </tr>
1630</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1631
1632<p>Note that the code generator does not yet support large vector types
1633to be used as function return types. The specific limit on how large a
1634vector return type codegen can currently handle is target-dependent;
1635currently it's often a few times longer than a hardware vector register.</p>
1636
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1637</div>
1638
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1639<!-- _______________________________________________________________________ -->
1640<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1641<div class="doc_text">
1642
1643<h5>Overview:</h5>
1644
1645<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksen8ac04ff2007-10-14 00:34:53 +0000[diff] [blame]1646corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1647In LLVM, opaque types can eventually be resolved to any type (not just a
1648structure type).</p>
1649
1650<h5>Syntax:</h5>
1651
1652<pre>
1653 opaque
1654</pre>
1655
1656<h5>Examples:</h5>
1657
1658<table class="layout">
1659 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1660 <td class="left"><tt>opaque</tt></td>
1661 <td class="left">An opaque type.</td>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1662 </tr>
1663</table>
1664</div>
1665
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1666<!-- ======================================================================= -->
1667<div class="doc_subsection">
1668 <a name="t_uprefs">Type Up-references</a>
1669</div>
1670
1671<div class="doc_text">
1672<h5>Overview:</h5>
1673<p>
1674An "up reference" allows you to refer to a lexically enclosing type without
1675requiring it to have a name. For instance, a structure declaration may contain a
1676pointer to any of the types it is lexically a member of. Example of up
1677references (with their equivalent as named type declarations) include:</p>
1678
1679<pre>
Chris Lattner3060f5b2009-02-09 10:00:56 +0000[diff] [blame]1680 { \2 * } %x = type { %x* }
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1681 { \2 }* %y = type { %y }*
1682 \1* %z = type %z*
1683</pre>
1684
1685<p>
1686An up reference is needed by the asmprinter for printing out cyclic types when
1687there is no declared name for a type in the cycle. Because the asmprinter does
1688not want to print out an infinite type string, it needs a syntax to handle
1689recursive types that have no names (all names are optional in llvm IR).
1690</p>
1691
1692<h5>Syntax:</h5>
1693<pre>
1694 \&lt;level&gt;
1695</pre>
1696
1697<p>
1698The level is the count of the lexical type that is being referred to.
1699</p>
1700
1701<h5>Examples:</h5>
1702
1703<table class="layout">
1704 <tr class="layout">
1705 <td class="left"><tt>\1*</tt></td>
1706 <td class="left">Self-referential pointer.</td>
1707 </tr>
1708 <tr class="layout">
1709 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
1710 <td class="left">Recursive structure where the upref refers to the out-most
1711 structure.</td>
1712 </tr>
1713</table>
1714</div>
1715
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1716
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1717<!-- *********************************************************************** -->
1718<div class="doc_section"> <a name="constants">Constants</a> </div>
1719<!-- *********************************************************************** -->
1720
1721<div class="doc_text">
1722
1723<p>LLVM has several different basic types of constants. This section describes
1724them all and their syntax.</p>
1725
1726</div>
1727
1728<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1729<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1730
1731<div class="doc_text">
1732
1733<dl>
1734 <dt><b>Boolean constants</b></dt>
1735
1736 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1737 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1738 </dd>
1739
1740 <dt><b>Integer constants</b></dt>
1741
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1742 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1743 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1744 integer types.
1745 </dd>
1746
1747 <dt><b>Floating point constants</b></dt>
1748
1749 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1750 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]1751 notation (see below). The assembler requires the exact decimal value of
1752 a floating-point constant. For example, the assembler accepts 1.25 but
1753 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1754 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1755
1756 <dt><b>Null pointer constants</b></dt>
1757
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1758 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1759 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1760
1761</dl>
1762
Dale Johannesenbd5e5a82009-02-11 22:14:51 +0000[diff] [blame]1763<p>The one non-intuitive notation for constants is the hexadecimal form
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1764of floating point constants. For example, the form '<tt>double
17650x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
17664.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1767(and the only time that they are generated by the disassembler) is when a
1768floating point constant must be emitted but it cannot be represented as a
Dale Johannesenbd5e5a82009-02-11 22:14:51 +0000[diff] [blame]1769decimal floating point number in a reasonable number of digits. For example,
1770NaN's, infinities, and other
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1771special values are represented in their IEEE hexadecimal format so that
1772assembly and disassembly do not cause any bits to change in the constants.</p>
Dale Johannesenbd5e5a82009-02-11 22:14:51 +0000[diff] [blame]1773<p>When using the hexadecimal form, constants of types float and double are
1774represented using the 16-digit form shown above (which matches the IEEE754
1775representation for double); float values must, however, be exactly representable
1776as IEE754 single precision.
1777Hexadecimal format is always used for long
1778double, and there are three forms of long double. The 80-bit
1779format used by x86 is represented as <tt>0xK</tt>
1780followed by 20 hexadecimal digits.
1781The 128-bit format used by PowerPC (two adjacent doubles) is represented
1782by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit
1783format is represented
1784by <tt>0xL</tt> followed by 32 hexadecimal digits; no currently supported
1785target uses this format. Long doubles will only work if they match
1786the long double format on your target. All hexadecimal formats are big-endian
1787(sign bit at the left).</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1788</div>
1789
1790<!-- ======================================================================= -->
1791<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1792</div>
1793
1794<div class="doc_text">
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]1795<p>Aggregate constants arise from aggregation of simple constants
1796and smaller aggregate constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1797
1798<dl>
1799 <dt><b>Structure constants</b></dt>
1800
1801 <dd>Structure constants are represented with notation similar to structure
1802 type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner64910ee2007-12-25 20:34:52 +0000[diff] [blame]1803 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1804 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]1805 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1806 types of elements must match those specified by the type.
1807 </dd>
1808
1809 <dt><b>Array constants</b></dt>
1810
1811 <dd>Array constants are represented with notation similar to array type
1812 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1813 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1814 constants must have <a href="#t_array">array type</a>, and the number and
1815 types of elements must match those specified by the type.
1816 </dd>
1817
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1818 <dt><b>Vector constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1819
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1820 <dd>Vector constants are represented with notation similar to vector type
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1821 definitions (a comma separated list of elements, surrounded by
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1822 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]1823 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1824 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1825 match those specified by the type.
1826 </dd>
1827
1828 <dt><b>Zero initialization</b></dt>
1829
1830 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1831 value to zero of <em>any</em> type, including scalar and aggregate types.
1832 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]1833 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1834 initializers.
1835 </dd>
1836</dl>
1837
1838</div>
1839
1840<!-- ======================================================================= -->
1841<div class="doc_subsection">
1842 <a name="globalconstants">Global Variable and Function Addresses</a>
1843</div>
1844
1845<div class="doc_text">
1846
1847<p>The addresses of <a href="#globalvars">global variables</a> and <a
1848href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1849constants. These constants are explicitly referenced when the <a
1850href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1851href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1852file:</p>
1853
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1854<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1855<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]1856@X = global i32 17
1857@Y = global i32 42
1858@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1859</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1860</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1861
1862</div>
1863
1864<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1865<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1866<div class="doc_text">
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1867 <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]1868 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1869 a constant is permitted.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1870
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1871 <p>Undefined values indicate to the compiler that the program is well defined
1872 no matter what value is used, giving the compiler more freedom to optimize.
1873 </p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1874</div>
1875
1876<!-- ======================================================================= -->
1877<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1878</div>
1879
1880<div class="doc_text">
1881
1882<p>Constant expressions are used to allow expressions involving other constants
1883to be used as constants. Constant expressions may be of any <a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1884href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1885that does not have side effects (e.g. load and call are not supported). The
1886following is the syntax for constant expressions:</p>
1887
1888<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1889 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1890 <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]1891 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1892
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1893 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1894 <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]1895 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]1896
1897 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1898 <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]1899 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]1900
1901 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1902 <dd>Truncate a floating point constant to another floating point type. The
1903 size of CST must be larger than the size of TYPE. Both types must be
1904 floating point.</dd>
1905
1906 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1907 <dd>Floating point extend a constant to another type. The size of CST must be
1908 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1909
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]1910 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1911 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1912 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1913 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1914 of the same number of elements. If the value won't fit in the integer type,
1915 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1916
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1917 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1918 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1919 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1920 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1921 of the same number of elements. If the value won't fit in the integer type,
1922 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1923
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1924 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1925 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1926 constant. TYPE must be a scalar or vector floating point type. CST must be of
1927 scalar or vector integer 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 floating point
1929 type, 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>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1932 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1933 constant. TYPE must be a scalar or vector floating point type. CST must be of
1934 scalar or vector integer 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 floating point
1936 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1937
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1938 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1939 <dd>Convert a pointer typed constant to the corresponding integer constant
1940 TYPE must be an integer type. CST must be of pointer type. The CST value is
1941 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1942
1943 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1944 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1945 pointer type. CST must be of integer type. The CST value is zero extended,
1946 truncated, or unchanged to make it fit in a pointer size. This one is
1947 <i>really</i> dangerous!</dd>
1948
1949 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1950 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1951 identical (same number of bits). The conversion is done as if the CST value
1952 was stored to memory and read back as TYPE. In other words, no bits change
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1953 with this operator, just the type. This can be used for conversion of
Nick Lewycky6cd74982009-02-28 17:30:06 +0000[diff] [blame]1954 aggregate types to any aggregate type, as long as they have the same bit
1955 width. Vector types may also be casted to and from any other type as long as
1956 they have the same bit width. For pointers it is only valid to cast to
1957 another pointer type.
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1958 </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1959
1960 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1961
1962 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1963 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1964 instruction, the index list may have zero or more indexes, which are required
1965 to make sense for the type of "CSTPTR".</dd>
1966
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1967 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1968
1969 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1970 constants.</dd>
1971
1972 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1973 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1974
1975 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1976 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1977
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]1978 <dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
1979 <dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
1980
1981 <dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
1982 <dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
1983
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1984 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1985
1986 <dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1987 operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1988
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1989 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1990
1991 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1992 operation</a> on constants.</dd>
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1993
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1994
1995 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1996
1997 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1998 operation</a> on constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1999
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2000 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
2001
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]2002 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2003 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2004 binary</a> operations. The constraints on operands are the same as those for
2005 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2006 values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2007</dl>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2008</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]2009
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2010<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2011<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
2012<!-- *********************************************************************** -->
2013
2014<!-- ======================================================================= -->
2015<div class="doc_subsection">
2016<a name="inlineasm">Inline Assembler Expressions</a>
2017</div>
2018
2019<div class="doc_text">
2020
2021<p>
2022LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
2023Module-Level Inline Assembly</a>) through the use of a special value. This
2024value represents the inline assembler as a string (containing the instructions
2025to emit), a list of operand constraints (stored as a string), and a flag that
2026indicates whether or not the inline asm expression has side effects. An example
2027inline assembler expression is:
2028</p>
2029
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2030<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2031<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2032i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2033</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2034</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2035
2036<p>
2037Inline assembler expressions may <b>only</b> be used as the callee operand of
2038a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
2039</p>
2040
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2041<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2042<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2043%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]2044</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2045</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2046
2047<p>
2048Inline asms with side effects not visible in the constraint list must be marked
2049as having side effects. This is done through the use of the
2050'<tt>sideeffect</tt>' keyword, like so:
2051</p>
2052
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2053<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2054<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2055call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2056</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2057</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2058
2059<p>TODO: The format of the asm and constraints string still need to be
2060documented here. Constraints on what can be done (e.g. duplication, moving, etc
Chris Lattner4f993352008-10-04 18:36:02 +0000[diff] [blame]2061need to be documented). This is probably best done by reference to another
2062document that covers inline asm from a holistic perspective.
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2063</p>
2064
2065</div>
2066
2067<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2068<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
2069<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2070
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2071<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2072
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2073<p>The LLVM instruction set consists of several different
2074classifications of instructions: <a href="#terminators">terminator
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2075instructions</a>, <a href="#binaryops">binary instructions</a>,
2076<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2077 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
2078instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2079
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2080</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2081
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2082<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2083<div class="doc_subsection"> <a name="terminators">Terminator
2084Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2085
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2086<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2087
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2088<p>As mentioned <a href="#functionstructure">previously</a>, every
2089basic block in a program ends with a "Terminator" instruction, which
2090indicates which block should be executed after the current block is
2091finished. These terminator instructions typically yield a '<tt>void</tt>'
2092value: they produce control flow, not values (the one exception being
2093the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2094<p>There are six different terminator instructions: the '<a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2095 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
2096instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2097the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
2098 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
2099 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2100
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2101</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2102
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2103<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2104<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
2105Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2106<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2107<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2108<pre>
2109 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]2110 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2111</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2112
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2113<h5>Overview:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2114
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2115<p>The '<tt>ret</tt>' instruction is used to return control flow (and
2116optionally a value) from a function back to the caller.</p>
John Criswell4457dc92004-04-09 16:48:45 +0000[diff] [blame]2117<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2118returns a value and then causes control flow, and one that just causes
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2119control flow to occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2120
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2121<h5>Arguments:</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 optionally accepts a single argument,
2124the return value. The type of the return value must be a
2125'<a href="#t_firstclass">first class</a>' type.</p>
2126
2127<p>A function is not <a href="#wellformed">well formed</a> if
2128it it has a non-void return type and contains a '<tt>ret</tt>'
2129instruction with no return value or a return value with a type that
2130does not match its type, or if it has a void return type and contains
2131a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2132
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2133<h5>Semantics:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2134
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2135<p>When the '<tt>ret</tt>' instruction is executed, control flow
2136returns back to the calling function's context. If the caller is a "<a
John Criswellfa081872004-06-25 15:16:57 +0000[diff] [blame]2137 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2138the instruction after the call. If the caller was an "<a
2139 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2140at the beginning of the "normal" destination block. If the instruction
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2141returns a value, that value shall set the call or invoke instruction's
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]2142return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2143
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2144<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2145
2146<pre>
2147 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2148 ret void <i>; Return from a void function</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2149 ret { i32, i8 } { i32 4, i8 2 } <i>; Return an aggregate of values 4 and 2</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2150</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2151
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]2152<p>Note that the code generator does not yet fully support large
2153 return values. The specific sizes that are currently supported are
2154 dependent on the target. For integers, on 32-bit targets the limit
2155 is often 64 bits, and on 64-bit targets the limit is often 128 bits.
2156 For aggregate types, the current limits are dependent on the element
2157 types; for example targets are often limited to 2 total integer
2158 elements and 2 total floating-point elements.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2159
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2160</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2161<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2162<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2163<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2164<h5>Syntax:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2165<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]2166</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2167<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2168<p>The '<tt>br</tt>' instruction is used to cause control flow to
2169transfer to a different basic block in the current function. There are
2170two forms of this instruction, corresponding to a conditional branch
2171and an unconditional branch.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2172<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2173<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2174single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]2175unconditional form of the '<tt>br</tt>' instruction takes a single
2176'<tt>label</tt>' value as a target.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2177<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2178<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2179argument is evaluated. If the value is <tt>true</tt>, control flows
2180to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2181control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2182<h5>Example:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2183<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]2184 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]2185</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2186<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2187<div class="doc_subsubsection">
2188 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2189</div>
2190
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2191<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2192<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2193
2194<pre>
2195 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2196</pre>
2197
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2198<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2199
2200<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
2201several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2202instruction, allowing a branch to occur to one of many possible
2203destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2204
2205
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2206<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2207
2208<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
2209comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
2210an array of pairs of comparison value constants and '<tt>label</tt>'s. The
2211table is not allowed to contain duplicate constant entries.</p>
2212
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2213<h5>Semantics:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2214
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2215<p>The <tt>switch</tt> instruction specifies a table of values and
2216destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]2217table is searched for the given value. If the value is found, control flow is
2218transfered to the corresponding destination; otherwise, control flow is
2219transfered to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2220
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2221<h5>Implementation:</h5>
2222
2223<p>Depending on properties of the target machine and the particular
2224<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]2225ways. For example, it could be generated as a series of chained conditional
2226branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2227
2228<h5>Example:</h5>
2229
2230<pre>
2231 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2232 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2233 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2234
2235 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2236 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2237
2238 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2239 switch i32 %val, label %otherwise [ i32 0, label %onzero
2240 i32 1, label %onone
2241 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2242</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2243</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2244
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2245<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2246<div class="doc_subsubsection">
2247 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2248</div>
2249
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2250<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2251
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2252<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2253
2254<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2255 &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]2256 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2257</pre>
2258
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2259<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2260
2261<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
2262function, with the possibility of control flow transfer to either the
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2263'<tt>normal</tt>' label or the
2264'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2265"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
2266"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2267href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]2268continued at the dynamically nearest "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2269
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2270<h5>Arguments:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2271
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2272<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2273
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2274<ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2275 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]2276 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2277 convention</a> the call should use. If none is specified, the call defaults
2278 to using C calling conventions.
2279 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2280
2281 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
2282 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
2283 and '<tt>inreg</tt>' attributes are valid here.</li>
2284
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2285 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
2286 function value being invoked. In most cases, this is a direct function
2287 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
2288 an arbitrary pointer to function value.
2289 </li>
2290
2291 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
2292 function to be invoked. </li>
2293
2294 <li>'<tt>function args</tt>': argument list whose types match the function
2295 signature argument types. If the function signature indicates the function
2296 accepts a variable number of arguments, the extra arguments can be
2297 specified. </li>
2298
2299 <li>'<tt>normal label</tt>': the label reached when the called function
2300 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
2301
2302 <li>'<tt>exception label</tt>': the label reached when a callee returns with
2303 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
2304
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2305 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2306 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2307 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2308</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2309
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2310<h5>Semantics:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2311
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2312<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2313href="#i_call">call</a></tt>' instruction in most regards. The primary
2314difference is that it establishes an association with a label, which is used by
2315the runtime library to unwind the stack.</p>
2316
2317<p>This instruction is used in languages with destructors to ensure that proper
2318cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2319exception. Additionally, this is important for implementation of
2320'<tt>catch</tt>' clauses in high-level languages that support them.</p>
2321
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2322<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2323<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2324 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2325 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2326 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2327 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2328</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2329</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2330
2331
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2332<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2333
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2334<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2335Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2336
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2337<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2338
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2339<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2340<pre>
2341 unwind
2342</pre>
2343
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2344<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2345
2346<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
2347at the first callee in the dynamic call stack which used an <a
2348href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
2349primarily used to implement exception handling.</p>
2350
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2351<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2352
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]2353<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2354immediately halt. The dynamic call stack is then searched for the first <a
2355href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
2356execution continues at the "exceptional" destination block specified by the
2357<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
2358dynamic call chain, undefined behavior results.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2359</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2360
2361<!-- _______________________________________________________________________ -->
2362
2363<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2364Instruction</a> </div>
2365
2366<div class="doc_text">
2367
2368<h5>Syntax:</h5>
2369<pre>
2370 unreachable
2371</pre>
2372
2373<h5>Overview:</h5>
2374
2375<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
2376instruction is used to inform the optimizer that a particular portion of the
2377code is not reachable. This can be used to indicate that the code after a
2378no-return function cannot be reached, and other facts.</p>
2379
2380<h5>Semantics:</h5>
2381
2382<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
2383</div>
2384
2385
2386
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2387<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2388<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2389<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2390<p>Binary operators are used to do most of the computation in a
Chris Lattner5a158142008-04-01 18:47:32 +0000[diff] [blame]2391program. They require two operands of the same type, execute an operation on them, and
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2392produce a single value. The operands might represent
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2393multiple 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]2394The result value has the same type as its operands.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2395<p>There are several different binary operators:</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2396</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2397<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2398<div class="doc_subsubsection">
2399 <a name="i_add">'<tt>add</tt>' Instruction</a>
2400</div>
2401
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2402<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2403
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2404<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2405
2406<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2407 &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]2408</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2409
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2410<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2411
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2412<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2413
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2414<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2415
2416<p>The two arguments to the '<tt>add</tt>' instruction must be <a
2417 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
2418 <a href="#t_vector">vector</a> values. Both arguments must have identical
2419 types.</p>
2420
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2421<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2422
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2423<p>The value produced is the integer or floating point sum of the two
2424operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2425
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2426<p>If an integer sum has unsigned overflow, the result returned is the
2427mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2428the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2429
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2430<p>Because LLVM integers use a two's complement representation, this
2431instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2432
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2433<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2434
2435<pre>
2436 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2437</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2438</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2439<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2440<div class="doc_subsubsection">
2441 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2442</div>
2443
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2444<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2445
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2446<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2447
2448<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2449 &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]2450</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2451
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2452<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2453
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2454<p>The '<tt>sub</tt>' instruction returns the difference of its two
2455operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2456
2457<p>Note that the '<tt>sub</tt>' instruction is used to represent the
2458'<tt>neg</tt>' instruction present in most other intermediate
2459representations.</p>
2460
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2461<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2462
2463<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
2464 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2465 or <a href="#t_vector">vector</a> values. Both arguments must have identical
2466 types.</p>
2467
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2468<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2469
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2470<p>The value produced is the integer or floating point difference of
2471the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2472
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2473<p>If an integer difference has unsigned overflow, the result returned is the
2474mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2475the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2476
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2477<p>Because LLVM integers use a two's complement representation, this
2478instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2479
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2480<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2481<pre>
2482 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2483 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2484</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2485</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2486
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2487<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2488<div class="doc_subsubsection">
2489 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2490</div>
2491
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2492<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2493
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2494<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2495<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]2496</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2497<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2498<p>The '<tt>mul</tt>' instruction returns the product of its two
2499operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2500
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2501<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2502
2503<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
2504href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2505or <a href="#t_vector">vector</a> values. Both arguments must have identical
2506types.</p>
2507
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2508<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2509
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2510<p>The value produced is the integer or floating point product of the
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2511two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2512
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2513<p>If the result of an integer multiplication has unsigned overflow,
2514the result returned is the mathematical result modulo
25152<sup>n</sup>, where n is the bit width of the result.</p>
2516<p>Because LLVM integers use a two's complement representation, and the
2517result is the same width as the operands, this instruction returns the
2518correct result for both signed and unsigned integers. If a full product
2519(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
2520should be sign-extended or zero-extended as appropriate to the
2521width of the full product.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2522<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2523<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]2524</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2525</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2526
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2527<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2528<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2529</a></div>
2530<div class="doc_text">
2531<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2532<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]2533</pre>
2534<h5>Overview:</h5>
2535<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2536operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2537
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2538<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2539
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2540<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2541<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2542values. Both arguments must have identical types.</p>
2543
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2544<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2545
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2546<p>The value produced is the unsigned integer quotient of the two operands.</p>
2547<p>Note that unsigned integer division and signed integer division are distinct
2548operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2549<p>Division by zero leads to undefined behavior.</p>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2550<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2551<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]2552</pre>
2553</div>
2554<!-- _______________________________________________________________________ -->
2555<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2556</a> </div>
2557<div class="doc_text">
2558<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2559<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2560 &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]2561</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2562
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2563<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2564
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2565<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2566operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2567
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2568<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2569
2570<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2571<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2572values. Both arguments must have identical types.</p>
2573
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2574<h5>Semantics:</h5>
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2575<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]2576<p>Note that signed integer division and unsigned integer division are distinct
2577operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2578<p>Division by zero leads to undefined behavior. Overflow also leads to
2579undefined behavior; this is a rare case, but can occur, for example,
2580by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2581<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2582<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]2583</pre>
2584</div>
2585<!-- _______________________________________________________________________ -->
2586<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2587Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2588<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2589<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2590<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2591 &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]2592</pre>
2593<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2594
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2595<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2596operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2597
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2598<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2599
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2600<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2601<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2602of floating point values. Both arguments must have identical types.</p>
2603
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2604<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2605
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2606<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2607
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2608<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2609
2610<pre>
2611 &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]2612</pre>
2613</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2614
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2615<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2616<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2617</div>
2618<div class="doc_text">
2619<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2620<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]2621</pre>
2622<h5>Overview:</h5>
2623<p>The '<tt>urem</tt>' instruction returns the remainder from the
2624unsigned division of its two arguments.</p>
2625<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2626<p>The two arguments to the '<tt>urem</tt>' instruction must be
2627<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2628values. Both arguments must have identical types.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2629<h5>Semantics:</h5>
2630<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2631This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2632<p>Note that unsigned integer remainder and signed integer remainder are
2633distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
2634<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2635<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2636<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]2637</pre>
2638
2639</div>
2640<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2641<div class="doc_subsubsection">
2642 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
2643</div>
2644
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2645<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2646
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2647<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2648
2649<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2650 &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]2651</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2652
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2653<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2654
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2655<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2656signed division of its two operands. This instruction can also take
2657<a href="#t_vector">vector</a> versions of the values in which case
2658the elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]2659
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2660<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2661
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2662<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2663<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2664values. Both arguments must have identical types.</p>
2665
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2666<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2667
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2668<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2669has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
2670operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2671a value. For more information about the difference, see <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2672 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2673Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencer64f5c6c2007-03-24 22:40:44 +0000[diff] [blame]2674please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2675Wikipedia: modulo operation</a>.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2676<p>Note that signed integer remainder and unsigned integer remainder are
2677distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
2678<p>Taking the remainder of a division by zero leads to undefined behavior.
2679Overflow also leads to undefined behavior; this is a rare case, but can occur,
2680for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
2681(The remainder doesn't actually overflow, but this rule lets srem be
2682implemented using instructions that return both the result of the division
2683and the remainder.)</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2684<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2685<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]2686</pre>
2687
2688</div>
2689<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2690<div class="doc_subsubsection">
2691 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
2692
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2693<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2694
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2695<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2696<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]2697</pre>
2698<h5>Overview:</h5>
2699<p>The '<tt>frem</tt>' instruction returns the remainder from the
2700division of its two operands.</p>
2701<h5>Arguments:</h5>
2702<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2703<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2704of floating point values. Both arguments must have identical types.</p>
2705
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2706<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2707
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2708<p>This instruction returns the <i>remainder</i> of a division.
2709The remainder has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2710
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2711<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2712
2713<pre>
2714 &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]2715</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2716</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]2717
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2718<!-- ======================================================================= -->
2719<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2720Operations</a> </div>
2721<div class="doc_text">
2722<p>Bitwise binary operators are used to do various forms of
2723bit-twiddling in a program. They are generally very efficient
2724instructions and can commonly be strength reduced from other
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2725instructions. They require two operands of the same type, execute an operation on them,
2726and 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]2727</div>
2728
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2729<!-- _______________________________________________________________________ -->
2730<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2731Instruction</a> </div>
2732<div class="doc_text">
2733<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2734<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]2735</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2736
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2737<h5>Overview:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2738
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2739<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2740the left a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2741
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2742<h5>Arguments:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2743
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2744<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2745 href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2746type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2747
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2748<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2749
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2750<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
2751where 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]2752equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
2753If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
2754corresponding shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2755
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2756<h5>Example:</h5><pre>
2757 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2758 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2759 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2760 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]2761 &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]2762</pre>
2763</div>
2764<!-- _______________________________________________________________________ -->
2765<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2766Instruction</a> </div>
2767<div class="doc_text">
2768<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2769<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]2770</pre>
2771
2772<h5>Overview:</h5>
2773<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2774operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2775
2776<h5>Arguments:</h5>
2777<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2778<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]2779type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2780
2781<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2782
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2783<p>This instruction always performs a logical shift right operation. The most
2784significant bits of the result will be filled with zero bits after the
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2785shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
Mon P Wang01f8d092008-12-10 08:55:09 +0000[diff] [blame]2786the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
2787vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
2788amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2789
2790<h5>Example:</h5>
2791<pre>
2792 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2793 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2794 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2795 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2796 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]2797 &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]2798</pre>
2799</div>
2800
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2801<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2802<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2803Instruction</a> </div>
2804<div class="doc_text">
2805
2806<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2807<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]2808</pre>
2809
2810<h5>Overview:</h5>
2811<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2812operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2813
2814<h5>Arguments:</h5>
2815<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2816<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]2817type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2818
2819<h5>Semantics:</h5>
2820<p>This instruction always performs an arithmetic shift right operation,
2821The most significant bits of the result will be filled with the sign bit
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2822of <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]2823larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
2824arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
2825corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2826
2827<h5>Example:</h5>
2828<pre>
2829 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2830 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2831 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2832 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2833 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]2834 &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]2835</pre>
2836</div>
2837
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2838<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2839<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2840Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2841
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2842<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2843
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2844<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2845
2846<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2847 &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]2848</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2849
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2850<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2851
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2852<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2853its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2854
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2855<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2856
2857<p>The two arguments to the '<tt>and</tt>' instruction must be
2858<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2859values. Both arguments must have identical types.</p>
2860
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2861<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2862<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2863<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2864<div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2865<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2866 <tbody>
2867 <tr>
2868 <td>In0</td>
2869 <td>In1</td>
2870 <td>Out</td>
2871 </tr>
2872 <tr>
2873 <td>0</td>
2874 <td>0</td>
2875 <td>0</td>
2876 </tr>
2877 <tr>
2878 <td>0</td>
2879 <td>1</td>
2880 <td>0</td>
2881 </tr>
2882 <tr>
2883 <td>1</td>
2884 <td>0</td>
2885 <td>0</td>
2886 </tr>
2887 <tr>
2888 <td>1</td>
2889 <td>1</td>
2890 <td>1</td>
2891 </tr>
2892 </tbody>
2893</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2894</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2895<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2896<pre>
2897 &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]2898 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2899 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2900</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2901</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2902<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2903<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2904<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2905<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2906<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]2907</pre>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2908<h5>Overview:</h5>
2909<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2910or of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2911<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2912
2913<p>The two arguments to the '<tt>or</tt>' instruction must be
2914<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2915values. Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2916<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2917<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2918<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2919<div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2920<table border="1" cellspacing="0" cellpadding="4">
2921 <tbody>
2922 <tr>
2923 <td>In0</td>
2924 <td>In1</td>
2925 <td>Out</td>
2926 </tr>
2927 <tr>
2928 <td>0</td>
2929 <td>0</td>
2930 <td>0</td>
2931 </tr>
2932 <tr>
2933 <td>0</td>
2934 <td>1</td>
2935 <td>1</td>
2936 </tr>
2937 <tr>
2938 <td>1</td>
2939 <td>0</td>
2940 <td>1</td>
2941 </tr>
2942 <tr>
2943 <td>1</td>
2944 <td>1</td>
2945 <td>1</td>
2946 </tr>
2947 </tbody>
2948</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2949</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2950<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2951<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2952 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2953 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2954</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2955</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2956<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2957<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2958Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2959<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2960<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2961<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]2962</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2963<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2964<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2965or of its two operands. The <tt>xor</tt> is used to implement the
2966"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2967<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2968<p>The two arguments to the '<tt>xor</tt>' instruction must be
2969<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2970values. Both arguments must have identical types.</p>
2971
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2972<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2973
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2974<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2975<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2976<div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2977<table border="1" cellspacing="0" cellpadding="4">
2978 <tbody>
2979 <tr>
2980 <td>In0</td>
2981 <td>In1</td>
2982 <td>Out</td>
2983 </tr>
2984 <tr>
2985 <td>0</td>
2986 <td>0</td>
2987 <td>0</td>
2988 </tr>
2989 <tr>
2990 <td>0</td>
2991 <td>1</td>
2992 <td>1</td>
2993 </tr>
2994 <tr>
2995 <td>1</td>
2996 <td>0</td>
2997 <td>1</td>
2998 </tr>
2999 <tr>
3000 <td>1</td>
3001 <td>1</td>
3002 <td>0</td>
3003 </tr>
3004 </tbody>
3005</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]3006</div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3007<p> </p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3008<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3009<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
3010 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
3011 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
3012 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3013</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3014</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3015
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3016<!-- ======================================================================= -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3017<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3018 <a name="vectorops">Vector Operations</a>
3019</div>
3020
3021<div class="doc_text">
3022
3023<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3024target-independent manner. These instructions cover the element-access and
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3025vector-specific operations needed to process vectors effectively. While LLVM
3026does directly support these vector operations, many sophisticated algorithms
3027will want to use target-specific intrinsics to take full advantage of a specific
3028target.</p>
3029
3030</div>
3031
3032<!-- _______________________________________________________________________ -->
3033<div class="doc_subsubsection">
3034 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
3035</div>
3036
3037<div class="doc_text">
3038
3039<h5>Syntax:</h5>
3040
3041<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3042 &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]3043</pre>
3044
3045<h5>Overview:</h5>
3046
3047<p>
3048The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3049element from a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3050</p>
3051
3052
3053<h5>Arguments:</h5>
3054
3055<p>
3056The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3057value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3058an index indicating the position from which to extract the element.
3059The index may be a variable.</p>
3060
3061<h5>Semantics:</h5>
3062
3063<p>
3064The result is a scalar of the same type as the element type of
3065<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
3066<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3067results are undefined.
3068</p>
3069
3070<h5>Example:</h5>
3071
3072<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3073 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3074</pre>
3075</div>
3076
3077
3078<!-- _______________________________________________________________________ -->
3079<div class="doc_subsubsection">
3080 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
3081</div>
3082
3083<div class="doc_text">
3084
3085<h5>Syntax:</h5>
3086
3087<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]3088 &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]3089</pre>
3090
3091<h5>Overview:</h5>
3092
3093<p>
3094The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3095element into a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3096</p>
3097
3098
3099<h5>Arguments:</h5>
3100
3101<p>
3102The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3103value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3104scalar value whose type must equal the element type of the first
3105operand. The third operand is an index indicating the position at
3106which to insert the value. The index may be a variable.</p>
3107
3108<h5>Semantics:</h5>
3109
3110<p>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3111The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3112element values are those of <tt>val</tt> except at position
3113<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
3114exceeds the length of <tt>val</tt>, the results are undefined.
3115</p>
3116
3117<h5>Example:</h5>
3118
3119<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3120 %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]3121</pre>
3122</div>
3123
3124<!-- _______________________________________________________________________ -->
3125<div class="doc_subsubsection">
3126 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3127</div>
3128
3129<div class="doc_text">
3130
3131<h5>Syntax:</h5>
3132
3133<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3134 &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]3135</pre>
3136
3137<h5>Overview:</h5>
3138
3139<p>
3140The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3141from two input vectors, returning a vector with the same element type as
3142the input and length that is the same as the shuffle mask.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3143</p>
3144
3145<h5>Arguments:</h5>
3146
3147<p>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3148The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
3149with types that match each other. The third argument is a shuffle mask whose
3150element type is always 'i32'. The result of the instruction is a vector whose
3151length is the same as the shuffle mask and whose element type is the same as
3152the element type of the first two operands.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3153</p>
3154
3155<p>
3156The shuffle mask operand is required to be a constant vector with either
3157constant integer or undef values.
3158</p>
3159
3160<h5>Semantics:</h5>
3161
3162<p>
3163The elements of the two input vectors are numbered from left to right across
3164both of the vectors. The shuffle mask operand specifies, for each element of
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3165the result vector, which element of the two input vectors the result element
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3166gets. The element selector may be undef (meaning "don't care") and the second
3167operand may be undef if performing a shuffle from only one vector.
3168</p>
3169
3170<h5>Example:</h5>
3171
3172<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3173 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3174 &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]3175 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
3176 &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]3177 %result = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
3178 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
3179 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
3180 &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]3181</pre>
3182</div>
3183
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]3184
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3185<!-- ======================================================================= -->
3186<div class="doc_subsection">
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3187 <a name="aggregateops">Aggregate Operations</a>
3188</div>
3189
3190<div class="doc_text">
3191
3192<p>LLVM supports several instructions for working with aggregate values.
3193</p>
3194
3195</div>
3196
3197<!-- _______________________________________________________________________ -->
3198<div class="doc_subsubsection">
3199 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3200</div>
3201
3202<div class="doc_text">
3203
3204<h5>Syntax:</h5>
3205
3206<pre>
3207 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3208</pre>
3209
3210<h5>Overview:</h5>
3211
3212<p>
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3213The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3214or array element from an aggregate value.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3215</p>
3216
3217
3218<h5>Arguments:</h5>
3219
3220<p>
3221The first operand of an '<tt>extractvalue</tt>' instruction is a
3222value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3223type. The operands are constant indices to specify which value to extract
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3224in a similar manner as indices in a
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3225'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3226</p>
3227
3228<h5>Semantics:</h5>
3229
3230<p>
3231The result is the value at the position in the aggregate specified by
3232the index operands.
3233</p>
3234
3235<h5>Example:</h5>
3236
3237<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3238 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3239</pre>
3240</div>
3241
3242
3243<!-- _______________________________________________________________________ -->
3244<div class="doc_subsubsection">
3245 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3246</div>
3247
3248<div class="doc_text">
3249
3250<h5>Syntax:</h5>
3251
3252<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3253 &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]3254</pre>
3255
3256<h5>Overview:</h5>
3257
3258<p>
3259The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3260into a struct field or array element in an aggregate.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3261</p>
3262
3263
3264<h5>Arguments:</h5>
3265
3266<p>
3267The first operand of an '<tt>insertvalue</tt>' instruction is a
3268value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
3269The second operand is a first-class value to insert.
Dan Gohmanc4b49eb2008-05-23 21:53:15 +0000[diff] [blame]3270The following operands are constant indices
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3271indicating the position at which to insert the value in a similar manner as
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3272indices in a
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3273'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3274The value to insert must have the same type as the value identified
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3275by the indices.
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3276</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3277
3278<h5>Semantics:</h5>
3279
3280<p>
3281The result is an aggregate of the same type as <tt>val</tt>. Its
3282value is that of <tt>val</tt> except that the value at the position
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3283specified by the indices is that of <tt>elt</tt>.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3284</p>
3285
3286<h5>Example:</h5>
3287
3288<pre>
Dan Gohman52bb2db2008-06-23 15:26:37 +0000[diff] [blame]3289 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3290</pre>
3291</div>
3292
3293
3294<!-- ======================================================================= -->
3295<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3296 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3297</div>
3298
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3299<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3300
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3301<p>A key design point of an SSA-based representation is how it
3302represents memory. In LLVM, no memory locations are in SSA form, which
3303makes things very simple. This section describes how to read, write,
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3304allocate, and free memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3305
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3306</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3307
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3308<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3309<div class="doc_subsubsection">
3310 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3311</div>
3312
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3313<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3314
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3315<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3316
3317<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3318 &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]3319</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3320
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3321<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3322
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3323<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]3324heap and returns a pointer to it. The object is always allocated in the generic
3325address space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3326
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3327<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3328
3329<p>The '<tt>malloc</tt>' instruction allocates
3330<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswell6e4ca612004-02-24 16:13:56 +0000[diff] [blame]3331bytes of memory from the operating system and returns a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3332appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3333number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3334If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3335be aligned to at least that boundary. If not specified, or if zero, the target can
3336choose to align the allocation on any convenient boundary.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3337
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3338<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3339
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3340<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3341
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3342<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewycky02ff3082008-11-24 03:41:24 +0000[diff] [blame]3343a pointer is returned. The result of a zero byte allocation is undefined. The
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3344result is null if there is insufficient memory available.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3345
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3346<h5>Example:</h5>
3347
3348<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3349 %array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3350
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3351 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3352 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3353 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3354 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3355 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3356</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]3357
3358<p>Note that the code generator does not yet respect the
3359 alignment value.</p>
3360
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3361</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3362
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3363<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3364<div class="doc_subsubsection">
3365 <a name="i_free">'<tt>free</tt>' Instruction</a>
3366</div>
3367
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3368<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3369
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3370<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3371
3372<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3373 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3374</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3375
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3376<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3377
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3378<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]3379memory heap to be reallocated in the future.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3380
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3381<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3382
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3383<p>'<tt>value</tt>' shall be a pointer value that points to a value
3384that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
3385instruction.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3386
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3387<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3388
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3389<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattnere0db56d2008-04-19 22:41:32 +0000[diff] [blame]3390after this instruction executes. If the pointer is null, the operation
3391is a noop.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3392
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3393<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3394
3395<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3396 %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]3397 free [4 x i8]* %array
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3398</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3399</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3400
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3401<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3402<div class="doc_subsubsection">
3403 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3404</div>
3405
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3406<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3407
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3408<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3409
3410<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3411 &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]3412</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3413
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3414<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3415
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3416<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
3417currently executing function, to be automatically released when this function
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]3418returns to its caller. The object is always allocated in the generic address
3419space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3420
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3421<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3422
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3423<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3424bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3425appropriate type to the program. If "NumElements" is specified, it is the
3426number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3427If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3428to be aligned to at least that boundary. If not specified, or if zero, the target
3429can choose to align the allocation on any convenient boundary.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3430
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3431<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3432
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3433<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3434
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3435<p>Memory is allocated; a pointer is returned. The operation is undefiend if
3436there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3437memory is automatically released when the function returns. The '<tt>alloca</tt>'
3438instruction is commonly used to represent automatic variables that must
3439have an address available. When the function returns (either with the <tt><a
John Criswelldae2e932005-05-12 16:55:34 +0000[diff] [blame]3440 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]3441instructions), the memory is reclaimed. Allocating zero bytes
3442is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3443
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3444<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3445
3446<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3447 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
3448 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3449 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
3450 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3451</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3452</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3453
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3454<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3455<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3456Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3457<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3458<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]3459<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]3460<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3461<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3462<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3463<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]3464address from which to load. The pointer must point to a <a
Chris Lattnere53e5082004-06-03 22:57:15 +0000[diff] [blame]3465 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]3466marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3467the number or order of execution of this <tt>load</tt> with other
3468volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3469instructions. </p>
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3470<p>
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3471The optional constant "align" argument specifies the alignment of the operation
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3472(that is, the alignment of the memory address). A value of 0 or an
3473omitted "align" argument means that the operation has the preferential
3474alignment for the target. It is the responsibility of the code emitter
3475to ensure that the alignment information is correct. Overestimating
3476the alignment results in an undefined behavior. Underestimating the
3477alignment may produce less efficient code. An alignment of 1 is always
3478safe.
3479</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3480<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3481<p>The location of memory pointed to is loaded.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3482<h5>Examples:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3483<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3484 <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3485 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
3486 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3487</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3488</div>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3489<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3490<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3491Instruction</a> </div>
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]3492<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3493<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]3494<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
3495 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]3496</pre>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3497<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3498<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3499<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3500<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3501to 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]3502operand must be a pointer to the <a href="#t_firstclass">first class</a> type
3503of the '<tt>&lt;value&gt;</tt>'
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]3504operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3505optimizer is not allowed to modify the number or order of execution of
3506this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
3507 href="#i_store">store</a></tt> instructions.</p>
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3508<p>
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3509The optional constant "align" argument specifies the alignment of the operation
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3510(that is, the alignment of the memory address). A value of 0 or an
3511omitted "align" argument means that the operation has the preferential
3512alignment for the target. It is the responsibility of the code emitter
3513to ensure that the alignment information is correct. Overestimating
3514the alignment results in an undefined behavior. Underestimating the
3515alignment may produce less efficient code. An alignment of 1 is always
3516safe.
3517</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3518<h5>Semantics:</h5>
3519<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
3520at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3521<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3522<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]3523 store i32 3, i32* %ptr <i>; yields {void}</i>
3524 %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]3525</pre>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3526</div>
3527
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3528<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3529<div class="doc_subsubsection">
3530 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3531</div>
3532
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3533<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3534<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3535<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3536 &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]3537</pre>
3538
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3539<h5>Overview:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3540
3541<p>
3542The '<tt>getelementptr</tt>' instruction is used to get the address of a
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3543subelement of an aggregate data structure. It performs address calculation only
3544and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3545
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3546<h5>Arguments:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3547
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3548<p>The first argument is always a pointer, and forms the basis of the
3549calculation. The remaining arguments are indices, that indicate which of the
3550elements of the aggregate object are indexed. The interpretation of each index
3551is dependent on the type being indexed into. The first index always indexes the
3552pointer value given as the first argument, the second index indexes a value of
3553the type pointed to (not necessarily the value directly pointed to, since the
3554first index can be non-zero), etc. The first type indexed into must be a pointer
3555value, subsequent types can be arrays, vectors and structs. Note that subsequent
3556types being indexed into can never be pointers, since that would require loading
3557the pointer before continuing calculation.</p>
3558
3559<p>The type of each index argument depends on the type it is indexing into.
3560When indexing into a (packed) structure, only <tt>i32</tt> integer
3561<b>constants</b> are allowed. When indexing into an array, pointer or vector,
3562only integers of 32 or 64 bits are allowed (also non-constants). 32-bit values
3563will be sign extended to 64-bits if required.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3564
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3565<p>For example, let's consider a C code fragment and how it gets
3566compiled to LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3567
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3568<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3569<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3570struct RT {
3571 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3572 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3573 char C;
3574};
3575struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3576 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3577 double Y;
3578 struct RT Z;
3579};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3580
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3581int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3582 return &amp;s[1].Z.B[5][13];
3583}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3584</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3585</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3586
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3587<p>The LLVM code generated by the GCC frontend is:</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>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]3591%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
3592%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3593
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3594define i32* %foo(%ST* %s) {
3595entry:
3596 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3597 ret i32* %reg
3598}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3599</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3600</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3601
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3602<h5>Semantics:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3603
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3604<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]3605type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3606}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3607the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3608i8 }</tt>' type, another structure. The third index indexes into the second
3609element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3610array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3611'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
3612to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3613
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3614<p>Note that it is perfectly legal to index partially through a
3615structure, returning a pointer to an inner element. Because of this,
3616the LLVM code for the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3617
3618<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3619 define i32* %foo(%ST* %s) {
3620 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3621 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3622 %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]3623 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3624 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
3625 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3626 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3627</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3628
3629<p>Note that it is undefined to access an array out of bounds: array and
3630pointer indexes must always be within the defined bounds of the array type.
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]3631The one exception for this rule is zero length arrays. These arrays are
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3632defined to be accessible as variable length arrays, which requires access
3633beyond the zero'th element.</p>
3634
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3635<p>The getelementptr instruction is often confusing. For some more insight
3636into how it works, see <a href="GetElementPtr.html">the getelementptr
3637FAQ</a>.</p>
3638
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3639<h5>Example:</h5>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3640
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3641<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3642 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3643 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
3644 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3645 %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]3646 <i>; yields i8*:eptr</i>
3647 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3648</pre>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3649</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3650
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3651<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3652<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3653</div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3654<div class="doc_text">
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3655<p>The instructions in this category are the conversion instructions (casting)
3656which all take a single operand and a type. They perform various bit conversions
3657on the operand.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3658</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3659
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3660<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3661<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3662 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
3663</div>
3664<div class="doc_text">
3665
3666<h5>Syntax:</h5>
3667<pre>
3668 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3669</pre>
3670
3671<h5>Overview:</h5>
3672<p>
3673The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
3674</p>
3675
3676<h5>Arguments:</h5>
3677<p>
3678The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
3679be 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]3680and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3681type. The bit size of <tt>value</tt> must be larger than the bit size of
3682<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3683
3684<h5>Semantics:</h5>
3685<p>
3686The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3687and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
3688larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
3689It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3690
3691<h5>Example:</h5>
3692<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3693 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3694 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
3695 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3696</pre>
3697</div>
3698
3699<!-- _______________________________________________________________________ -->
3700<div class="doc_subsubsection">
3701 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
3702</div>
3703<div class="doc_text">
3704
3705<h5>Syntax:</h5>
3706<pre>
3707 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3708</pre>
3709
3710<h5>Overview:</h5>
3711<p>The '<tt>zext</tt>' instruction zero extends its operand to type
3712<tt>ty2</tt>.</p>
3713
3714
3715<h5>Arguments:</h5>
3716<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]3717<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3718also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3719<tt>value</tt> must be smaller than the bit size of the destination type,
3720<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3721
3722<h5>Semantics:</h5>
3723<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]3724bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3725
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]3726<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]3727
3728<h5>Example:</h5>
3729<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3730 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3731 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3732</pre>
3733</div>
3734
3735<!-- _______________________________________________________________________ -->
3736<div class="doc_subsubsection">
3737 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3738</div>
3739<div class="doc_text">
3740
3741<h5>Syntax:</h5>
3742<pre>
3743 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3744</pre>
3745
3746<h5>Overview:</h5>
3747<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3748
3749<h5>Arguments:</h5>
3750<p>
3751The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3752<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3753also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3754<tt>value</tt> must be smaller than the bit size of the destination type,
3755<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3756
3757<h5>Semantics:</h5>
3758<p>
3759The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3760bit (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]3761the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3762
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3763<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]3764
3765<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3766<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3767 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3768 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3769</pre>
3770</div>
3771
3772<!-- _______________________________________________________________________ -->
3773<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3774 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3775</div>
3776
3777<div class="doc_text">
3778
3779<h5>Syntax:</h5>
3780
3781<pre>
3782 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3783</pre>
3784
3785<h5>Overview:</h5>
3786<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3787<tt>ty2</tt>.</p>
3788
3789
3790<h5>Arguments:</h5>
3791<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3792 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3793cast it to. The size of <tt>value</tt> must be larger than the size of
3794<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3795<i>no-op cast</i>.</p>
3796
3797<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3798<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3799<a href="#t_floating">floating point</a> type to a smaller
3800<a href="#t_floating">floating point</a> type. If the value cannot fit within
3801the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3802
3803<h5>Example:</h5>
3804<pre>
3805 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3806 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3807</pre>
3808</div>
3809
3810<!-- _______________________________________________________________________ -->
3811<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3812 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3813</div>
3814<div class="doc_text">
3815
3816<h5>Syntax:</h5>
3817<pre>
3818 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3819</pre>
3820
3821<h5>Overview:</h5>
3822<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3823floating point value.</p>
3824
3825<h5>Arguments:</h5>
3826<p>The '<tt>fpext</tt>' instruction takes a
3827<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3828and a <a href="#t_floating">floating point</a> type to cast it to. The source
3829type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3830
3831<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3832<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3833<a href="#t_floating">floating point</a> type to a larger
3834<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3835used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3836<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]3837
3838<h5>Example:</h5>
3839<pre>
3840 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3841 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3842</pre>
3843</div>
3844
3845<!-- _______________________________________________________________________ -->
3846<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]3847 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3848</div>
3849<div class="doc_text">
3850
3851<h5>Syntax:</h5>
3852<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3853 &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]3854</pre>
3855
3856<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3857<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3858unsigned integer equivalent of type <tt>ty2</tt>.
3859</p>
3860
3861<h5>Arguments:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3862<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]3863scalar or vector <a href="#t_floating">floating point</a> value, and a type
3864to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3865type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3866vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3867
3868<h5>Semantics:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3869<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3870<a href="#t_floating">floating point</a> operand into the nearest (rounding
3871towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3872the results are undefined.</p>
3873
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3874<h5>Example:</h5>
3875<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3876 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3877 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3878 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3879</pre>
3880</div>
3881
3882<!-- _______________________________________________________________________ -->
3883<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3884 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3885</div>
3886<div class="doc_text">
3887
3888<h5>Syntax:</h5>
3889<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3890 &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]3891</pre>
3892
3893<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3894<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3895<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]3896</p>
3897
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3898<h5>Arguments:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3899<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]3900scalar or vector <a href="#t_floating">floating point</a> value, and a type
3901to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3902type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3903vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3904
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3905<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3906<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3907<a href="#t_floating">floating point</a> operand into the nearest (rounding
3908towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3909the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3910
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3911<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3912<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3913 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3914 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3915 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3916</pre>
3917</div>
3918
3919<!-- _______________________________________________________________________ -->
3920<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3921 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3922</div>
3923<div class="doc_text">
3924
3925<h5>Syntax:</h5>
3926<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3927 &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]3928</pre>
3929
3930<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3931<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3932integer and converts that value to the <tt>ty2</tt> type.</p>
3933
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3934<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3935<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3936scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3937to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3938type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3939floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3940
3941<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3942<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3943integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3944the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3945
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3946<h5>Example:</h5>
3947<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3948 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3949 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3950</pre>
3951</div>
3952
3953<!-- _______________________________________________________________________ -->
3954<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3955 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3956</div>
3957<div class="doc_text">
3958
3959<h5>Syntax:</h5>
3960<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3961 &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]3962</pre>
3963
3964<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3965<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3966integer and converts that value to the <tt>ty2</tt> type.</p>
3967
3968<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3969<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3970scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3971to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3972type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3973floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3974
3975<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3976<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3977integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3978the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3979
3980<h5>Example:</h5>
3981<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3982 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3983 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3984</pre>
3985</div>
3986
3987<!-- _______________________________________________________________________ -->
3988<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3989 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3990</div>
3991<div class="doc_text">
3992
3993<h5>Syntax:</h5>
3994<pre>
3995 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3996</pre>
3997
3998<h5>Overview:</h5>
3999<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
4000the integer type <tt>ty2</tt>.</p>
4001
4002<h5>Arguments:</h5>
4003<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4004must 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]4005<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]4006
4007<h5>Semantics:</h5>
4008<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
4009<tt>ty2</tt> by interpreting the pointer value as an integer and either
4010truncating or zero extending that value to the size of the integer type. If
4011<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
4012<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]4013are the same size, then nothing is done (<i>no-op cast</i>) other than a type
4014change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4015
4016<h5>Example:</h5>
4017<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4018 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
4019 %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]4020</pre>
4021</div>
4022
4023<!-- _______________________________________________________________________ -->
4024<div class="doc_subsubsection">
4025 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
4026</div>
4027<div class="doc_text">
4028
4029<h5>Syntax:</h5>
4030<pre>
4031 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4032</pre>
4033
4034<h5>Overview:</h5>
4035<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
4036a pointer type, <tt>ty2</tt>.</p>
4037
4038<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4039<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4040value to cast, and a type to cast it to, which must be a
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4041<a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4042
4043<h5>Semantics:</h5>
4044<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
4045<tt>ty2</tt> by applying either a zero extension or a truncation depending on
4046the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
4047size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
4048the size of a pointer then a zero extension is done. If they are the same size,
4049nothing is done (<i>no-op cast</i>).</p>
4050
4051<h5>Example:</h5>
4052<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4053 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
4054 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
4055 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4056</pre>
4057</div>
4058
4059<!-- _______________________________________________________________________ -->
4060<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4061 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4062</div>
4063<div class="doc_text">
4064
4065<h5>Syntax:</h5>
4066<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4067 &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]4068</pre>
4069
4070<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4071
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4072<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4073<tt>ty2</tt> without changing any bits.</p>
4074
4075<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4076
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4077<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Dan Gohman500233a2008-09-08 16:45:59 +0000[diff] [blame]4078a non-aggregate first class value, and a type to cast it to, which must also be
4079a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
4080<tt>value</tt>
Reid Spencer19b569f2007-01-09 20:08:58 +0000[diff] [blame]4081and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4082type is a pointer, the destination type must also be a pointer. This
4083instruction supports bitwise conversion of vectors to integers and to vectors
4084of other types (as long as they have the same size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4085
4086<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4087<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4088<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
4089this conversion. The conversion is done as if the <tt>value</tt> had been
4090stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
4091converted to other pointer types with this instruction. To convert pointers to
4092other types, use the <a href="#i_inttoptr">inttoptr</a> or
4093<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4094
4095<h5>Example:</h5>
4096<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4097 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4098 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4099 %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]4100</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4101</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4102
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4103<!-- ======================================================================= -->
4104<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
4105<div class="doc_text">
4106<p>The instructions in this category are the "miscellaneous"
4107instructions, which defy better classification.</p>
4108</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4109
4110<!-- _______________________________________________________________________ -->
4111<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4112</div>
4113<div class="doc_text">
4114<h5>Syntax:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4115<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]4116</pre>
4117<h5>Overview:</h5>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4118<p>The '<tt>icmp</tt>' instruction returns a boolean value or
4119a vector of boolean values based on comparison
4120of its two integer, integer vector, or pointer operands.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4121<h5>Arguments:</h5>
4122<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4123the condition code indicating the kind of comparison to perform. It is not
4124a value, just a keyword. The possible condition code are:
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4125</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4126<ol>
4127 <li><tt>eq</tt>: equal</li>
4128 <li><tt>ne</tt>: not equal </li>
4129 <li><tt>ugt</tt>: unsigned greater than</li>
4130 <li><tt>uge</tt>: unsigned greater or equal</li>
4131 <li><tt>ult</tt>: unsigned less than</li>
4132 <li><tt>ule</tt>: unsigned less or equal</li>
4133 <li><tt>sgt</tt>: signed greater than</li>
4134 <li><tt>sge</tt>: signed greater or equal</li>
4135 <li><tt>slt</tt>: signed less than</li>
4136 <li><tt>sle</tt>: signed less or equal</li>
4137</ol>
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]4138<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4139<a href="#t_pointer">pointer</a>
4140or integer <a href="#t_vector">vector</a> typed.
4141They must also be identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4142<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4143<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]4144the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4145yields 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]4146</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4147<ol>
4148 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
4149 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
4150 </li>
4151 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4152 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4153 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4154 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4155 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4156 <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]4157 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4158 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4159 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4160 <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]4161 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4162 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4163 <li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4164 <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]4165 <li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4166 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4167 <li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4168 <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]4169</ol>
4170<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4171values are compared as if they were integers.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4172<p>If the operands are integer vectors, then they are compared
4173element by element. The result is an <tt>i1</tt> vector with
4174the same number of elements as the values being compared.
4175Otherwise, the result is an <tt>i1</tt>.
4176</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4177
4178<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4179<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
4180 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4181 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4182 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4183 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4184 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4185</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4186
4187<p>Note that the code generator does not yet support vector types with
4188 the <tt>icmp</tt> instruction.</p>
4189
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4190</div>
4191
4192<!-- _______________________________________________________________________ -->
4193<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4194</div>
4195<div class="doc_text">
4196<h5>Syntax:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4197<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]4198</pre>
4199<h5>Overview:</h5>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4200<p>The '<tt>fcmp</tt>' instruction returns a boolean value
4201or vector of boolean values based on comparison
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4202of its operands.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4203<p>
4204If the operands are floating point scalars, then the result
4205type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
4206</p>
4207<p>If the operands are floating point vectors, then the result type
4208is a vector of boolean with the same number of elements as the
4209operands being compared.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4210<h5>Arguments:</h5>
4211<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4212the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4213a value, just a keyword. The possible condition code are:</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4214<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4215 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4216 <li><tt>oeq</tt>: ordered and equal</li>
4217 <li><tt>ogt</tt>: ordered and greater than </li>
4218 <li><tt>oge</tt>: ordered and greater than or equal</li>
4219 <li><tt>olt</tt>: ordered and less than </li>
4220 <li><tt>ole</tt>: ordered and less than or equal</li>
4221 <li><tt>one</tt>: ordered and not equal</li>
4222 <li><tt>ord</tt>: ordered (no nans)</li>
4223 <li><tt>ueq</tt>: unordered or equal</li>
4224 <li><tt>ugt</tt>: unordered or greater than </li>
4225 <li><tt>uge</tt>: unordered or greater than or equal</li>
4226 <li><tt>ult</tt>: unordered or less than </li>
4227 <li><tt>ule</tt>: unordered or less than or equal</li>
4228 <li><tt>une</tt>: unordered or not equal</li>
4229 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4230 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4231</ol>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4232<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer93a49852006-12-06 07:08:07 +0000[diff] [blame]4233<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4234<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
4235either a <a href="#t_floating">floating point</a> type
4236or a <a href="#t_vector">vector</a> of floating point type.
4237They must have identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4238<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4239<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4240according to the condition code given as <tt>cond</tt>.
4241If the operands are vectors, then the vectors are compared
4242element by element.
4243Each comparison performed
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4244always yields an <a href="#t_primitive">i1</a> result, as follows:</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4245<ol>
4246 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4247 <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]4248 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4249 <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]4250 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4251 <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]4252 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4253 <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]4254 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4255 <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]4256 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4257 <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]4258 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4259 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
4260 <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]4261 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4262 <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]4263 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4264 <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]4265 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4266 <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]4267 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4268 <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]4269 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4270 <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]4271 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4272 <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]4273 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4274</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4275
4276<h5>Example:</h5>
4277<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]4278 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4279 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4280 &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]4281</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4282
4283<p>Note that the code generator does not yet support vector types with
4284 the <tt>fcmp</tt> instruction.</p>
4285
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4286</div>
4287
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4288<!-- _______________________________________________________________________ -->
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4289<div class="doc_subsubsection">
4290 <a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
4291</div>
4292<div class="doc_text">
4293<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4294<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]4295</pre>
4296<h5>Overview:</h5>
4297<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
4298element-wise comparison of its two integer vector operands.</p>
4299<h5>Arguments:</h5>
4300<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
4301the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4302a value, just a keyword. The possible condition code are:</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4303<ol>
4304 <li><tt>eq</tt>: equal</li>
4305 <li><tt>ne</tt>: not equal </li>
4306 <li><tt>ugt</tt>: unsigned greater than</li>
4307 <li><tt>uge</tt>: unsigned greater or equal</li>
4308 <li><tt>ult</tt>: unsigned less than</li>
4309 <li><tt>ule</tt>: unsigned less or equal</li>
4310 <li><tt>sgt</tt>: signed greater than</li>
4311 <li><tt>sge</tt>: signed greater or equal</li>
4312 <li><tt>slt</tt>: signed less than</li>
4313 <li><tt>sle</tt>: signed less or equal</li>
4314</ol>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4315<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4316<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
4317<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4318<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4319according to the condition code given as <tt>cond</tt>. The comparison yields a
4320<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
4321identical type as the values being compared. The most significant bit in each
4322element is 1 if the element-wise comparison evaluates to true, and is 0
4323otherwise. All other bits of the result are undefined. The condition codes
4324are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4325instruction</a>.</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4326
4327<h5>Example:</h5>
4328<pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4329 &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>
4330 &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]4331</pre>
4332</div>
4333
4334<!-- _______________________________________________________________________ -->
4335<div class="doc_subsubsection">
4336 <a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
4337</div>
4338<div class="doc_text">
4339<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4340<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]4341<h5>Overview:</h5>
4342<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
4343element-wise comparison of its two floating point vector operands. The output
4344elements have the same width as the input elements.</p>
4345<h5>Arguments:</h5>
4346<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
4347the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4348a value, just a keyword. The possible condition code are:</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4349<ol>
4350 <li><tt>false</tt>: no comparison, always returns false</li>
4351 <li><tt>oeq</tt>: ordered and equal</li>
4352 <li><tt>ogt</tt>: ordered and greater than </li>
4353 <li><tt>oge</tt>: ordered and greater than or equal</li>
4354 <li><tt>olt</tt>: ordered and less than </li>
4355 <li><tt>ole</tt>: ordered and less than or equal</li>
4356 <li><tt>one</tt>: ordered and not equal</li>
4357 <li><tt>ord</tt>: ordered (no nans)</li>
4358 <li><tt>ueq</tt>: unordered or equal</li>
4359 <li><tt>ugt</tt>: unordered or greater than </li>
4360 <li><tt>uge</tt>: unordered or greater than or equal</li>
4361 <li><tt>ult</tt>: unordered or less than </li>
4362 <li><tt>ule</tt>: unordered or less than or equal</li>
4363 <li><tt>une</tt>: unordered or not equal</li>
4364 <li><tt>uno</tt>: unordered (either nans)</li>
4365 <li><tt>true</tt>: no comparison, always returns true</li>
4366</ol>
4367<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
4368<a href="#t_floating">floating point</a> typed. They must also be identical
4369types.</p>
4370<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4371<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4372according to the condition code given as <tt>cond</tt>. The comparison yields a
4373<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
4374an identical number of elements as the values being compared, and each element
4375having identical with to the width of the floating point elements. The most
4376significant bit in each element is 1 if the element-wise comparison evaluates to
4377true, and is 0 otherwise. All other bits of the result are undefined. The
4378condition codes are evaluated identically to the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4379<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4380
4381<h5>Example:</h5>
4382<pre>
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]4383 <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0, i32 -1 &gt;</i>
4384 &lt;result&gt; = vfcmp oeq &lt;2 x float&gt; &lt; float 4, float 0 &gt;, &lt; float 5, float 0 &gt;
4385
4386 <i>; yields: result=&lt;2 x i64&gt; &lt; i64 -1, i64 0 &gt;</i>
4387 &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]4388</pre>
4389</div>
4390
4391<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4392<div class="doc_subsubsection">
4393 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4394</div>
4395
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4396<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4397
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4398<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4399
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4400<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
4401<h5>Overview:</h5>
4402<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
4403the SSA graph representing the function.</p>
4404<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4405
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4406<p>The type of the incoming values is specified with the first type
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4407field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
4408as arguments, with one pair for each predecessor basic block of the
4409current block. Only values of <a href="#t_firstclass">first class</a>
4410type may be used as the value arguments to the PHI node. Only labels
4411may be used as the label arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4412
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4413<p>There must be no non-phi instructions between the start of a basic
4414block and the PHI instructions: i.e. PHI instructions must be first in
4415a basic block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4416
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4417<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4418
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4419<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
4420specified by the pair corresponding to the predecessor basic block that executed
4421just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4422
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4423<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4424<pre>
4425Loop: ; Infinite loop that counts from 0 on up...
4426 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4427 %nextindvar = add i32 %indvar, 1
4428 br label %Loop
4429</pre>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4430</div>
4431
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4432<!-- _______________________________________________________________________ -->
4433<div class="doc_subsubsection">
4434 <a name="i_select">'<tt>select</tt>' Instruction</a>
4435</div>
4436
4437<div class="doc_text">
4438
4439<h5>Syntax:</h5>
4440
4441<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4442 &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>
4443
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4444 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4445</pre>
4446
4447<h5>Overview:</h5>
4448
4449<p>
4450The '<tt>select</tt>' instruction is used to choose one value based on a
4451condition, without branching.
4452</p>
4453
4454
4455<h5>Arguments:</h5>
4456
4457<p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4458The '<tt>select</tt>' instruction requires an 'i1' value or
4459a vector of 'i1' values indicating the
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4460condition, and two values of the same <a href="#t_firstclass">first class</a>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4461type. If the val1/val2 are vectors and
4462the condition is a scalar, then entire vectors are selected, not
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4463individual elements.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4464</p>
4465
4466<h5>Semantics:</h5>
4467
4468<p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4469If 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]4470value argument; otherwise, it returns the second value argument.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4471</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4472<p>
4473If the condition is a vector of i1, then the value arguments must
4474be vectors of the same size, and the selection is done element
4475by element.
4476</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4477
4478<h5>Example:</h5>
4479
4480<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4481 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4482</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4483
4484<p>Note that the code generator does not yet support conditions
4485 with vector type.</p>
4486
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4487</div>
4488
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]4489
4490<!-- _______________________________________________________________________ -->
4491<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4492 <a name="i_call">'<tt>call</tt>' Instruction</a>
4493</div>
4494
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4495<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4496
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4497<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4498<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]4499 &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]4500</pre>
4501
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4502<h5>Overview:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4503
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4504<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4505
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4506<h5>Arguments:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4507
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4508<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4509
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4510<ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4511 <li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4512 <p>The optional "tail" marker indicates whether the callee function accesses
4513 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4514 function call is eligible for tail call optimization. Note that calls may
4515 be marked "tail" even if they do not occur before a <a
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4516 href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4517 </li>
4518 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4519 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4520 convention</a> the call should use. If none is specified, the call defaults
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4521 to using C calling conventions.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4522 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4523
4524 <li>
4525 <p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4526 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
4527 and '<tt>inreg</tt>' attributes are valid here.</p>
4528 </li>
4529
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4530 <li>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4531 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
4532 the type of the return value. Functions that return no value are marked
4533 <tt><a href="#t_void">void</a></tt>.</p>
4534 </li>
4535 <li>
4536 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
4537 value being invoked. The argument types must match the types implied by
4538 this signature. This type can be omitted if the function is not varargs
4539 and if the function type does not return a pointer to a function.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4540 </li>
4541 <li>
4542 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4543 be invoked. In most cases, this is a direct function invocation, but
4544 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4545 to function value.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4546 </li>
4547 <li>
4548 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencera7e302a2005-05-01 22:22:57 +0000[diff] [blame]4549 function signature argument types. All arguments must be of
4550 <a href="#t_firstclass">first class</a> type. If the function signature
4551 indicates the function accepts a variable number of arguments, the extra
4552 arguments can be specified.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4553 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4554 <li>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]4555 <p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4556 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
4557 '<tt>readnone</tt>' attributes are valid here.</p>
4558 </li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4559</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4560
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4561<h5>Semantics:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4562
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4563<p>The '<tt>call</tt>' instruction is used to cause control flow to
4564transfer to a specified function, with its incoming arguments bound to
4565the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
4566instruction in the called function, control flow continues with the
4567instruction after the function call, and the return value of the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4568function is bound to the result argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4569
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4570<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4571
4572<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4573 %retval = call i32 @test(i32 %argc)
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]4574 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4575 %X = tail call i32 @foo() <i>; yields i32</i>
4576 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4577 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]4578
4579 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4580 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]4581 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
4582 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]4583 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]4584 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4585</pre>
4586
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4587</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4588
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4589<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4590<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]4591 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4592</div>
4593
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4594<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4595
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4596<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4597
4598<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4599 &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]4600</pre>
4601
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4602<h5>Overview:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4603
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4604<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4605the "variable argument" area of a function call. It is used to implement the
4606<tt>va_arg</tt> macro in C.</p>
4607
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4608<h5>Arguments:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4609
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4610<p>This instruction takes a <tt>va_list*</tt> value and the type of
4611the argument. It returns a value of the specified argument type and
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4612increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4613actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4614
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4615<h5>Semantics:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4616
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4617<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
4618type from the specified <tt>va_list</tt> and causes the
4619<tt>va_list</tt> to point to the next argument. For more information,
4620see the variable argument handling <a href="#int_varargs">Intrinsic
4621Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4622
4623<p>It is legal for this instruction to be called in a function which does not
4624take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4625function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4626
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4627<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4628href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4629argument.</p>
4630
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4631<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4632
4633<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4634
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]4635<p>Note that the code generator does not yet fully support va_arg
4636 on many targets. Also, it does not currently support va_arg with
4637 aggregate types on any target.</p>
4638
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4639</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4640
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4641<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4642<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4643<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4644
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4645<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4646
4647<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4648well known names and semantics and are required to follow certain restrictions.
4649Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4650language that does not require changing all of the transformations in LLVM when
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]4651adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4652
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4653<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4654prefix is reserved in LLVM for intrinsic names; thus, function names may not
4655begin with this prefix. Intrinsic functions must always be external functions:
4656you cannot define the body of intrinsic functions. Intrinsic functions may
4657only be used in call or invoke instructions: it is illegal to take the address
4658of an intrinsic function. Additionally, because intrinsic functions are part
4659of the LLVM language, it is required if any are added that they be documented
4660here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4661
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4662<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
4663a family of functions that perform the same operation but on different data
4664types. Because LLVM can represent over 8 million different integer types,
4665overloading is used commonly to allow an intrinsic function to operate on any
4666integer type. One or more of the argument types or the result type can be
4667overloaded to accept any integer type. Argument types may also be defined as
4668exactly matching a previous argument's type or the result type. This allows an
4669intrinsic function which accepts multiple arguments, but needs all of them to
4670be of the same type, to only be overloaded with respect to a single argument or
4671the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4672
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4673<p>Overloaded intrinsics will have the names of its overloaded argument types
4674encoded into its function name, each preceded by a period. Only those types
4675which are overloaded result in a name suffix. Arguments whose type is matched
4676against another type do not. For example, the <tt>llvm.ctpop</tt> function can
4677take an integer of any width and returns an integer of exactly the same integer
4678width. This leads to a family of functions such as
4679<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
4680Only one type, the return type, is overloaded, and only one type suffix is
4681required. Because the argument's type is matched against the return type, it
4682does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4683
4684<p>To learn how to add an intrinsic function, please see the
4685<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4686</p>
4687
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4688</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4689
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4690<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4691<div class="doc_subsection">
4692 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
4693</div>
4694
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4695<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4696
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4697<p>Variable argument support is defined in LLVM with the <a
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]4698 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4699intrinsic functions. These functions are related to the similarly
4700named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4701
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4702<p>All of these functions operate on arguments that use a
4703target-specific value type "<tt>va_list</tt>". The LLVM assembly
4704language reference manual does not define what this type is, so all
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4705transformations should be prepared to handle these functions regardless of
4706the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4707
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]4708<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]4709instruction and the variable argument handling intrinsic functions are
4710used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4711
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4712<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4713<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4714define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4715 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4716 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4717 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4718 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4719
4720 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4721 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4722
4723 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4724 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4725 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4726 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4727 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4728
4729 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4730 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4731 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4732}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4733
4734declare void @llvm.va_start(i8*)
4735declare void @llvm.va_copy(i8*, i8*)
4736declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4737</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4738</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4739
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4740</div>
4741
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4742<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4743<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4744 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4745</div>
4746
4747
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4748<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4749<h5>Syntax:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4750<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4751<h5>Overview:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4752<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4753<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
4754href="#i_va_arg">va_arg</a></tt>.</p>
4755
4756<h5>Arguments:</h5>
4757
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4758<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]4759
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4760<h5>Semantics:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4761
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4762<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]4763macro available in C. In a target-dependent way, it initializes the
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4764<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]4765<tt>va_arg</tt> will produce the first variable argument passed to the function.
4766Unlike 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]4767last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4768
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4769</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4770
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4771<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4772<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4773 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4774</div>
4775
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4776<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4777<h5>Syntax:</h5>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4778<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4779<h5>Overview:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4780
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4781<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4782which 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]4783or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4784
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4785<h5>Arguments:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4786
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4787<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]4788
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4789<h5>Semantics:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4790
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4791<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]4792macro available in C. In a target-dependent way, it destroys the
4793<tt>va_list</tt> element to which the argument points. Calls to <a
4794href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
4795<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
4796<tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4797
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4798</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4799
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4800<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4801<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4802 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4803</div>
4804
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4805<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4806
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4807<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4808
4809<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4810 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4811</pre>
4812
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4813<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4814
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4815<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
4816from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4817
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4818<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4819
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4820<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]4821The 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]4822
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4823
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4824<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4825
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4826<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
4827macro available in C. In a target-dependent way, it copies the source
4828<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
4829intrinsic is necessary because the <tt><a href="#int_va_start">
4830llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
4831example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4832
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4833</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4834
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4835<!-- ======================================================================= -->
4836<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4837 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
4838</div>
4839
4840<div class="doc_text">
4841
4842<p>
4843LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]4844Collection</a> (GC) requires the implementation and generation of these
4845intrinsics.
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4846These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4847stack</a>, as well as garbage collector implementations that require <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4848href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4849Front-ends for type-safe garbage collected languages should generate these
4850intrinsics to make use of the LLVM garbage collectors. For more details, see <a
4851href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
4852</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]4853
4854<p>The garbage collection intrinsics only operate on objects in the generic
4855 address space (address space zero).</p>
4856
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4857</div>
4858
4859<!-- _______________________________________________________________________ -->
4860<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4861 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4862</div>
4863
4864<div class="doc_text">
4865
4866<h5>Syntax:</h5>
4867
4868<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4869 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4870</pre>
4871
4872<h5>Overview:</h5>
4873
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]4874<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]4875the code generator, and allows some metadata to be associated with it.</p>
4876
4877<h5>Arguments:</h5>
4878
4879<p>The first argument specifies the address of a stack object that contains the
4880root pointer. The second pointer (which must be either a constant or a global
4881value address) contains the meta-data to be associated with the root.</p>
4882
4883<h5>Semantics:</h5>
4884
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]4885<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]4886location. At compile-time, the code generator generates information to allow
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4887the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
4888intrinsic may only be used in a function which <a href="#gc">specifies a GC
4889algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4890
4891</div>
4892
4893
4894<!-- _______________________________________________________________________ -->
4895<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4896 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4897</div>
4898
4899<div class="doc_text">
4900
4901<h5>Syntax:</h5>
4902
4903<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4904 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4905</pre>
4906
4907<h5>Overview:</h5>
4908
4909<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4910locations, allowing garbage collector implementations that require read
4911barriers.</p>
4912
4913<h5>Arguments:</h5>
4914
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4915<p>The second argument is the address to read from, which should be an address
4916allocated from the garbage collector. The first object is a pointer to the
4917start of the referenced object, if needed by the language runtime (otherwise
4918null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4919
4920<h5>Semantics:</h5>
4921
4922<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4923instruction, but may be replaced with substantially more complex code by the
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4924garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
4925may only be used in a function which <a href="#gc">specifies a GC
4926algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4927
4928</div>
4929
4930
4931<!-- _______________________________________________________________________ -->
4932<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4933 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4934</div>
4935
4936<div class="doc_text">
4937
4938<h5>Syntax:</h5>
4939
4940<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4941 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4942</pre>
4943
4944<h5>Overview:</h5>
4945
4946<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4947locations, allowing garbage collector implementations that require write
4948barriers (such as generational or reference counting collectors).</p>
4949
4950<h5>Arguments:</h5>
4951
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4952<p>The first argument is the reference to store, the second is the start of the
4953object to store it to, and the third is the address of the field of Obj to
4954store to. If the runtime does not require a pointer to the object, Obj may be
4955null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4956
4957<h5>Semantics:</h5>
4958
4959<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4960instruction, but may be replaced with substantially more complex code by the
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4961garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
4962may only be used in a function which <a href="#gc">specifies a GC
4963algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4964
4965</div>
4966
4967
4968
4969<!-- ======================================================================= -->
4970<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4971 <a name="int_codegen">Code Generator Intrinsics</a>
4972</div>
4973
4974<div class="doc_text">
4975<p>
4976These intrinsics are provided by LLVM to expose special features that may only
4977be implemented with code generator support.
4978</p>
4979
4980</div>
4981
4982<!-- _______________________________________________________________________ -->
4983<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4984 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4985</div>
4986
4987<div class="doc_text">
4988
4989<h5>Syntax:</h5>
4990<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4991 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4992</pre>
4993
4994<h5>Overview:</h5>
4995
4996<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4997The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4998target-specific value indicating the return address of the current function
4999or one of its callers.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5000</p>
5001
5002<h5>Arguments:</h5>
5003
5004<p>
5005The argument to this intrinsic indicates which function to return the address
5006for. Zero indicates the calling function, one indicates its caller, etc. The
5007argument is <b>required</b> to be a constant integer value.
5008</p>
5009
5010<h5>Semantics:</h5>
5011
5012<p>
5013The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
5014the return address of the specified call frame, or zero if it cannot be
5015identified. The value returned by this intrinsic is likely to be incorrect or 0
5016for arguments other than zero, so it should only be used for debugging purposes.
5017</p>
5018
5019<p>
5020Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]5021aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5022source-language caller.
5023</p>
5024</div>
5025
5026
5027<!-- _______________________________________________________________________ -->
5028<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5029 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5030</div>
5031
5032<div class="doc_text">
5033
5034<h5>Syntax:</h5>
5035<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5036 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5037</pre>
5038
5039<h5>Overview:</h5>
5040
5041<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]5042The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5043target-specific frame pointer value for the specified stack frame.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5044</p>
5045
5046<h5>Arguments:</h5>
5047
5048<p>
5049The argument to this intrinsic indicates which function to return the frame
5050pointer for. Zero indicates the calling function, one indicates its caller,
5051etc. The argument is <b>required</b> to be a constant integer value.
5052</p>
5053
5054<h5>Semantics:</h5>
5055
5056<p>
5057The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
5058the frame address of the specified call frame, or zero if it cannot be
5059identified. The value returned by this intrinsic is likely to be incorrect or 0
5060for arguments other than zero, so it should only be used for debugging purposes.
5061</p>
5062
5063<p>
5064Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]5065aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5066source-language caller.
5067</p>
5068</div>
5069
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5070<!-- _______________________________________________________________________ -->
5071<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5072 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5073</div>
5074
5075<div class="doc_text">
5076
5077<h5>Syntax:</h5>
5078<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5079 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5080</pre>
5081
5082<h5>Overview:</h5>
5083
5084<p>
5085The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5086the function stack, for use with <a href="#int_stackrestore">
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5087<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
5088features like scoped automatic variable sized arrays in C99.
5089</p>
5090
5091<h5>Semantics:</h5>
5092
5093<p>
5094This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5095href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5096<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
5097<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
5098state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
5099practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
5100that were allocated after the <tt>llvm.stacksave</tt> was executed.
5101</p>
5102
5103</div>
5104
5105<!-- _______________________________________________________________________ -->
5106<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5107 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5108</div>
5109
5110<div class="doc_text">
5111
5112<h5>Syntax:</h5>
5113<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5114 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5115</pre>
5116
5117<h5>Overview:</h5>
5118
5119<p>
5120The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5121the function stack to the state it was in when the corresponding <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5122href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5123useful for implementing language features like scoped automatic variable sized
5124arrays in C99.
5125</p>
5126
5127<h5>Semantics:</h5>
5128
5129<p>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5130See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5131</p>
5132
5133</div>
5134
5135
5136<!-- _______________________________________________________________________ -->
5137<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5138 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5139</div>
5140
5141<div class="doc_text">
5142
5143<h5>Syntax:</h5>
5144<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5145 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]5146</pre>
5147
5148<h5>Overview:</h5>
5149
5150
5151<p>
5152The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5153a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
5154no
5155effect on the behavior of the program but can change its performance
Chris Lattner2a615362005-02-28 19:47:14 +0000[diff] [blame]5156characteristics.
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5157</p>
5158
5159<h5>Arguments:</h5>
5160
5161<p>
5162<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
5163determining if the fetch should be for a read (0) or write (1), and
5164<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattneraeffb4a2005-03-07 20:31:38 +0000[diff] [blame]5165locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5166<tt>locality</tt> arguments must be constant integers.
5167</p>
5168
5169<h5>Semantics:</h5>
5170
5171<p>
5172This intrinsic does not modify the behavior of the program. In particular,
5173prefetches cannot trap and do not produce a value. On targets that support this
5174intrinsic, the prefetch can provide hints to the processor cache for better
5175performance.
5176</p>
5177
5178</div>
5179
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5180<!-- _______________________________________________________________________ -->
5181<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5182 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5183</div>
5184
5185<div class="doc_text">
5186
5187<h5>Syntax:</h5>
5188<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5189 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5190</pre>
5191
5192<h5>Overview:</h5>
5193
5194
5195<p>
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5196The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5197(PC) in a region of
5198code to simulators and other tools. The method is target specific, but it is
5199expected that the marker will use exported symbols to transmit the PC of the
5200marker.
5201The marker makes no guarantees that it will remain with any specific instruction
5202after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb3e7afd2006-03-24 07:16:10 +0000[diff] [blame]5203optimizations. The intended use is to be inserted after optimizations to allow
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5204correlations of simulation runs.
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5205</p>
5206
5207<h5>Arguments:</h5>
5208
5209<p>
5210<tt>id</tt> is a numerical id identifying the marker.
5211</p>
5212
5213<h5>Semantics:</h5>
5214
5215<p>
5216This intrinsic does not modify the behavior of the program. Backends that do not
5217support this intrinisic may ignore it.
5218</p>
5219
5220</div>
5221
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5222<!-- _______________________________________________________________________ -->
5223<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5224 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5225</div>
5226
5227<div class="doc_text">
5228
5229<h5>Syntax:</h5>
5230<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5231 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5232</pre>
5233
5234<h5>Overview:</h5>
5235
5236
5237<p>
5238The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5239counter register (or similar low latency, high accuracy clocks) on those targets
5240that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
5241As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
5242should only be used for small timings.
5243</p>
5244
5245<h5>Semantics:</h5>
5246
5247<p>
5248When directly supported, reading the cycle counter should not modify any memory.
5249Implementations are allowed to either return a application specific value or a
5250system wide value. On backends without support, this is lowered to a constant 0.
5251</p>
5252
5253</div>
5254
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5255<!-- ======================================================================= -->
5256<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5257 <a name="int_libc">Standard C Library Intrinsics</a>
5258</div>
5259
5260<div class="doc_text">
5261<p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5262LLVM provides intrinsics for a few important standard C library functions.
5263These intrinsics allow source-language front-ends to pass information about the
5264alignment of the pointer arguments to the code generator, providing opportunity
5265for more efficient code generation.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5266</p>
5267
5268</div>
5269
5270<!-- _______________________________________________________________________ -->
5271<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5272 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5273</div>
5274
5275<div class="doc_text">
5276
5277<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5278<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
5279width. Not all targets support all bit widths however.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5280<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5281 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5282 i8 &lt;len&gt;, i32 &lt;align&gt;)
5283 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5284 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5285 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5286 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5287 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5288 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5289</pre>
5290
5291<h5>Overview:</h5>
5292
5293<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5294The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5295location to the destination location.
5296</p>
5297
5298<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5299Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5300intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5301</p>
5302
5303<h5>Arguments:</h5>
5304
5305<p>
5306The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5307the source. The third argument is an integer argument
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5308specifying the number of bytes to copy, and the fourth argument is the alignment
5309of the source and destination locations.
5310</p>
5311
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5312<p>
5313If 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]5314the caller guarantees that both the source and destination pointers are aligned
5315to that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5316</p>
5317
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5318<h5>Semantics:</h5>
5319
5320<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5321The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5322location to the destination location, which are not allowed to overlap. It
5323copies "len" bytes of memory over. If the argument is known to be aligned to
5324some boundary, this can be specified as the fourth argument, otherwise it should
5325be set to 0 or 1.
5326</p>
5327</div>
5328
5329
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5330<!-- _______________________________________________________________________ -->
5331<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5332 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5333</div>
5334
5335<div class="doc_text">
5336
5337<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5338<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
5339width. Not all targets support all bit widths however.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5340<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5341 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5342 i8 &lt;len&gt;, i32 &lt;align&gt;)
5343 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5344 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5345 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5346 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5347 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5348 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5349</pre>
5350
5351<h5>Overview:</h5>
5352
5353<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5354The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
5355location to the destination location. It is similar to the
Chris Lattner4b2cbcf2008-01-06 19:51:52 +0000[diff] [blame]5356'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5357</p>
5358
5359<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5360Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5361intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5362</p>
5363
5364<h5>Arguments:</h5>
5365
5366<p>
5367The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5368the source. The third argument is an integer argument
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5369specifying the number of bytes to copy, and the fourth argument is the alignment
5370of the source and destination locations.
5371</p>
5372
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5373<p>
5374If 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]5375the caller guarantees that the source and destination pointers are aligned to
5376that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5377</p>
5378
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5379<h5>Semantics:</h5>
5380
5381<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5382The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5383location to the destination location, which may overlap. It
5384copies "len" bytes of memory over. If the argument is known to be aligned to
5385some boundary, this can be specified as the fourth argument, otherwise it should
5386be set to 0 or 1.
5387</p>
5388</div>
5389
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5390
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5391<!-- _______________________________________________________________________ -->
5392<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5393 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5394</div>
5395
5396<div class="doc_text">
5397
5398<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5399<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
5400width. Not all targets support all bit widths however.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5401<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5402 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5403 i8 &lt;len&gt;, i32 &lt;align&gt;)
5404 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5405 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5406 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5407 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5408 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5409 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5410</pre>
5411
5412<h5>Overview:</h5>
5413
5414<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5415The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5416byte value.
5417</p>
5418
5419<p>
5420Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
5421does not return a value, and takes an extra alignment argument.
5422</p>
5423
5424<h5>Arguments:</h5>
5425
5426<p>
5427The first argument is a pointer to the destination to fill, the second is the
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5428byte value to fill it with, the third argument is an integer
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5429argument specifying the number of bytes to fill, and the fourth argument is the
5430known alignment of destination location.
5431</p>
5432
5433<p>
5434If 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]5435the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5436</p>
5437
5438<h5>Semantics:</h5>
5439
5440<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5441The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
5442the
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5443destination location. If the argument is known to be aligned to some boundary,
5444this can be specified as the fourth argument, otherwise it should be set to 0 or
54451.
5446</p>
5447</div>
5448
5449
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5450<!-- _______________________________________________________________________ -->
5451<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5452 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5453</div>
5454
5455<div class="doc_text">
5456
5457<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5458<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]5459floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5460types however.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5461<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5462 declare float @llvm.sqrt.f32(float %Val)
5463 declare double @llvm.sqrt.f64(double %Val)
5464 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5465 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5466 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5467</pre>
5468
5469<h5>Overview:</h5>
5470
5471<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5472The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5473returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5474<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner103e2d72008-01-29 07:00:44 +0000[diff] [blame]5475negative numbers other than -0.0 (which allows for better optimization, because
5476there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
5477defined to return -0.0 like IEEE sqrt.
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5478</p>
5479
5480<h5>Arguments:</h5>
5481
5482<p>
5483The argument and return value are floating point numbers of the same type.
5484</p>
5485
5486<h5>Semantics:</h5>
5487
5488<p>
Dan Gohmand6257fe2007-07-16 14:37:41 +0000[diff] [blame]5489This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5490floating point number.
5491</p>
5492</div>
5493
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5494<!-- _______________________________________________________________________ -->
5495<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5496 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5497</div>
5498
5499<div class="doc_text">
5500
5501<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5502<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]5503floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5504types however.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5505<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5506 declare float @llvm.powi.f32(float %Val, i32 %power)
5507 declare double @llvm.powi.f64(double %Val, i32 %power)
5508 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5509 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5510 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5511</pre>
5512
5513<h5>Overview:</h5>
5514
5515<p>
5516The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5517specified (positive or negative) power. The order of evaluation of
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5518multiplications is not defined. When a vector of floating point type is
5519used, the second argument remains a scalar integer value.
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5520</p>
5521
5522<h5>Arguments:</h5>
5523
5524<p>
5525The second argument is an integer power, and the first is a value to raise to
5526that power.
5527</p>
5528
5529<h5>Semantics:</h5>
5530
5531<p>
5532This function returns the first value raised to the second power with an
5533unspecified sequence of rounding operations.</p>
5534</div>
5535
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5536<!-- _______________________________________________________________________ -->
5537<div class="doc_subsubsection">
5538 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5539</div>
5540
5541<div class="doc_text">
5542
5543<h5>Syntax:</h5>
5544<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5545floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5546types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5547<pre>
5548 declare float @llvm.sin.f32(float %Val)
5549 declare double @llvm.sin.f64(double %Val)
5550 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5551 declare fp128 @llvm.sin.f128(fp128 %Val)
5552 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5553</pre>
5554
5555<h5>Overview:</h5>
5556
5557<p>
5558The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
5559</p>
5560
5561<h5>Arguments:</h5>
5562
5563<p>
5564The argument and return value are floating point numbers of the same type.
5565</p>
5566
5567<h5>Semantics:</h5>
5568
5569<p>
5570This function returns the sine of the specified operand, returning the
5571same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5572conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5573</div>
5574
5575<!-- _______________________________________________________________________ -->
5576<div class="doc_subsubsection">
5577 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5578</div>
5579
5580<div class="doc_text">
5581
5582<h5>Syntax:</h5>
5583<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5584floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5585types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5586<pre>
5587 declare float @llvm.cos.f32(float %Val)
5588 declare double @llvm.cos.f64(double %Val)
5589 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5590 declare fp128 @llvm.cos.f128(fp128 %Val)
5591 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5592</pre>
5593
5594<h5>Overview:</h5>
5595
5596<p>
5597The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
5598</p>
5599
5600<h5>Arguments:</h5>
5601
5602<p>
5603The argument and return value are floating point numbers of the same type.
5604</p>
5605
5606<h5>Semantics:</h5>
5607
5608<p>
5609This function returns the cosine of the specified operand, returning the
5610same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5611conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5612</div>
5613
5614<!-- _______________________________________________________________________ -->
5615<div class="doc_subsubsection">
5616 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5617</div>
5618
5619<div class="doc_text">
5620
5621<h5>Syntax:</h5>
5622<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5623floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5624types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5625<pre>
5626 declare float @llvm.pow.f32(float %Val, float %Power)
5627 declare double @llvm.pow.f64(double %Val, double %Power)
5628 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5629 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5630 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5631</pre>
5632
5633<h5>Overview:</h5>
5634
5635<p>
5636The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5637specified (positive or negative) power.
5638</p>
5639
5640<h5>Arguments:</h5>
5641
5642<p>
5643The second argument is a floating point power, and the first is a value to
5644raise to that power.
5645</p>
5646
5647<h5>Semantics:</h5>
5648
5649<p>
5650This function returns the first value raised to the second power,
5651returning the
5652same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5653conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5654</div>
5655
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5656
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5657<!-- ======================================================================= -->
5658<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5659 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5660</div>
5661
5662<div class="doc_text">
5663<p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5664LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5665These allow efficient code generation for some algorithms.
5666</p>
5667
5668</div>
5669
5670<!-- _______________________________________________________________________ -->
5671<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5672 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5673</div>
5674
5675<div class="doc_text">
5676
5677<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5678<p>This is an overloaded intrinsic function. You can use bswap on any integer
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5679type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5680<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5681 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5682 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5683 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5684</pre>
5685
5686<h5>Overview:</h5>
5687
5688<p>
Reid Spencer338ea092007-04-02 02:25:19 +0000[diff] [blame]5689The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5690values with an even number of bytes (positive multiple of 16 bits). These are
5691useful for performing operations on data that is not in the target's native
5692byte order.
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5693</p>
5694
5695<h5>Semantics:</h5>
5696
5697<p>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5698The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5699and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
5700intrinsic returns an i32 value that has the four bytes of the input i32
5701swapped, 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]5702i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
5703<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5704additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5705</p>
5706
5707</div>
5708
5709<!-- _______________________________________________________________________ -->
5710<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5711 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5712</div>
5713
5714<div class="doc_text">
5715
5716<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5717<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]5718width. Not all targets support all bit widths however.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5719<pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5720 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5721 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5722 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5723 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5724 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5725</pre>
5726
5727<h5>Overview:</h5>
5728
5729<p>
Chris Lattnerec6cb612006-01-16 22:38:59 +0000[diff] [blame]5730The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
5731value.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5732</p>
5733
5734<h5>Arguments:</h5>
5735
5736<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]5737The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5738integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5739</p>
5740
5741<h5>Semantics:</h5>
5742
5743<p>
5744The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
5745</p>
5746</div>
5747
5748<!-- _______________________________________________________________________ -->
5749<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5750 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5751</div>
5752
5753<div class="doc_text">
5754
5755<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5756<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]5757integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5758<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5759 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5760 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5761 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5762 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5763 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5764</pre>
5765
5766<h5>Overview:</h5>
5767
5768<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5769The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5770leading zeros in a variable.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5771</p>
5772
5773<h5>Arguments:</h5>
5774
5775<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]5776The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5777integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5778</p>
5779
5780<h5>Semantics:</h5>
5781
5782<p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5783The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
5784in 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]5785of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5786</p>
5787</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5788
5789
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5790
5791<!-- _______________________________________________________________________ -->
5792<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5793 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5794</div>
5795
5796<div class="doc_text">
5797
5798<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5799<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]5800integer bit width. Not all targets support all bit widths however.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5801<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5802 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5803 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5804 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5805 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5806 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5807</pre>
5808
5809<h5>Overview:</h5>
5810
5811<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5812The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5813trailing zeros.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5814</p>
5815
5816<h5>Arguments:</h5>
5817
5818<p>
5819The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5820integer type. The return type must match the argument type.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5821</p>
5822
5823<h5>Semantics:</h5>
5824
5825<p>
5826The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
5827in a variable. If the src == 0 then the result is the size in bits of the type
5828of src. For example, <tt>llvm.cttz(2) = 1</tt>.
5829</p>
5830</div>
5831
Reid Spencer497d93e2007-04-01 08:27:01 +0000[diff] [blame]5832<!-- _______________________________________________________________________ -->
5833<div class="doc_subsubsection">
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5834 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5835</div>
5836
5837<div class="doc_text">
5838
5839<h5>Syntax:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5840<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5841on any integer bit width.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5842<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5843 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
5844 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5845</pre>
5846
5847<h5>Overview:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5848<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5849range of bits from an integer value and returns them in the same bit width as
5850the original value.</p>
5851
5852<h5>Arguments:</h5>
5853<p>The first argument, <tt>%val</tt> and the result may be integer types of
5854any bit width but they must have the same bit width. The second and third
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5855arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5856
5857<h5>Semantics:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5858<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5859of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
5860<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
5861operates in forward mode.</p>
5862<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
5863right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5864only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
5865<ol>
5866 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
5867 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
5868 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
5869 to determine the number of bits to retain.</li>
5870 <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]5871 <li>The mask is ANDed with <tt>%val</tt> to produce the result.</li>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5872</ol>
Reid Spencerd6a85b52007-05-14 16:14:57 +0000[diff] [blame]5873<p>In reverse mode, a similar computation is made except that the bits are
5874returned in the reverse order. So, for example, if <tt>X</tt> has the value
5875<tt>i16 0x0ACF (101011001111)</tt> and we apply
5876<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
5877<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5878</div>
5879
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5880<div class="doc_subsubsection">
5881 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
5882</div>
5883
5884<div class="doc_text">
5885
5886<h5>Syntax:</h5>
5887<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5888on any integer bit width.</p>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5889<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5890 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
5891 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]5892</pre>
5893
5894<h5>Overview:</h5>
5895<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
5896of bits in an integer value with another integer value. It returns the integer
5897with the replaced bits.</p>
5898
5899<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5900<p>The first argument, <tt>%val</tt>, and the result may be integer types of
5901any 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]5902whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
5903integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
5904type since they specify only a bit index.</p>
5905
5906<h5>Semantics:</h5>
5907<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
5908of operation: forwards and reverse. If <tt>%lo</tt> is greater than
5909<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
5910operates in forward mode.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5911
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5912<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
5913truncating it down to the size of the replacement area or zero extending it
5914up to that size.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5915
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5916<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5917are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5918in <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]5919to the <tt>%hi</tt>th bit.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5920
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5921<p>In reverse mode, a similar computation is made except that the bits are
5922reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5923<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]5924
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5925<h5>Examples:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5926
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5927<pre>
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5928 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5929 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5930 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5931 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5932 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]5933</pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5934
5935</div>
5936
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5937<!-- ======================================================================= -->
5938<div class="doc_subsection">
5939 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
5940</div>
5941
5942<div class="doc_text">
5943<p>
5944LLVM provides intrinsics for some arithmetic with overflow operations.
5945</p>
5946
5947</div>
5948
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5949<!-- _______________________________________________________________________ -->
5950<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5951 <a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5952</div>
5953
5954<div class="doc_text">
5955
5956<h5>Syntax:</h5>
5957
5958<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]5959on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5960
5961<pre>
5962 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
5963 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
5964 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
5965</pre>
5966
5967<h5>Overview:</h5>
5968
5969<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
5970a signed addition of the two arguments, and indicate whether an overflow
5971occurred during the signed summation.</p>
5972
5973<h5>Arguments:</h5>
5974
5975<p>The arguments (%a and %b) and the first element of the result structure may
5976be of integer types of any bit width, but they must have the same bit width. The
5977second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
5978and <tt>%b</tt> are the two values that will undergo signed addition.</p>
5979
5980<h5>Semantics:</h5>
5981
5982<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
5983a signed addition of the two variables. They return a structure &mdash; the
5984first element of which is the signed summation, and the second element of which
5985is a bit specifying if the signed summation resulted in an overflow.</p>
5986
5987<h5>Examples:</h5>
5988<pre>
5989 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
5990 %sum = extractvalue {i32, i1} %res, 0
5991 %obit = extractvalue {i32, i1} %res, 1
5992 br i1 %obit, label %overflow, label %normal
5993</pre>
5994
5995</div>
5996
5997<!-- _______________________________________________________________________ -->
5998<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5999 <a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6000</div>
6001
6002<div class="doc_text">
6003
6004<h5>Syntax:</h5>
6005
6006<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]6007on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6008
6009<pre>
6010 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6011 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6012 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6013</pre>
6014
6015<h5>Overview:</h5>
6016
6017<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
6018an unsigned addition of the two arguments, and indicate whether a carry occurred
6019during the unsigned summation.</p>
6020
6021<h5>Arguments:</h5>
6022
6023<p>The arguments (%a and %b) and the first element of the result structure may
6024be of integer types of any bit width, but they must have the same bit width. The
6025second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
6026and <tt>%b</tt> are the two values that will undergo unsigned addition.</p>
6027
6028<h5>Semantics:</h5>
6029
6030<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
6031an unsigned addition of the two arguments. They return a structure &mdash; the
6032first element of which is the sum, and the second element of which is a bit
6033specifying if the unsigned summation resulted in a carry.</p>
6034
6035<h5>Examples:</h5>
6036<pre>
6037 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6038 %sum = extractvalue {i32, i1} %res, 0
6039 %obit = extractvalue {i32, i1} %res, 1
6040 br i1 %obit, label %carry, label %normal
6041</pre>
6042
6043</div>
6044
6045<!-- _______________________________________________________________________ -->
6046<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6047 <a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6048</div>
6049
6050<div class="doc_text">
6051
6052<h5>Syntax:</h5>
6053
6054<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]6055on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6056
6057<pre>
6058 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6059 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6060 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6061</pre>
6062
6063<h5>Overview:</h5>
6064
6065<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
6066a signed subtraction of the two arguments, and indicate whether an overflow
6067occurred during the signed subtraction.</p>
6068
6069<h5>Arguments:</h5>
6070
6071<p>The arguments (%a and %b) and the first element of the result structure may
6072be of integer types of any bit width, but they must have the same bit width. The
6073second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
6074and <tt>%b</tt> are the two values that will undergo signed subtraction.</p>
6075
6076<h5>Semantics:</h5>
6077
6078<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
6079a signed subtraction of the two arguments. They return a structure &mdash; the
6080first element of which is the subtraction, and the second element of which is a bit
6081specifying if the signed subtraction resulted in an overflow.</p>
6082
6083<h5>Examples:</h5>
6084<pre>
6085 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6086 %sum = extractvalue {i32, i1} %res, 0
6087 %obit = extractvalue {i32, i1} %res, 1
6088 br i1 %obit, label %overflow, label %normal
6089</pre>
6090
6091</div>
6092
6093<!-- _______________________________________________________________________ -->
6094<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6095 <a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6096</div>
6097
6098<div class="doc_text">
6099
6100<h5>Syntax:</h5>
6101
6102<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]6103on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6104
6105<pre>
6106 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6107 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6108 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6109</pre>
6110
6111<h5>Overview:</h5>
6112
6113<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
6114an unsigned subtraction of the two arguments, and indicate whether an overflow
6115occurred during the unsigned subtraction.</p>
6116
6117<h5>Arguments:</h5>
6118
6119<p>The arguments (%a and %b) and the first element of the result structure may
6120be of integer types of any bit width, but they must have the same bit width. The
6121second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
6122and <tt>%b</tt> are the two values that will undergo unsigned subtraction.</p>
6123
6124<h5>Semantics:</h5>
6125
6126<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
6127an unsigned subtraction of the two arguments. They return a structure &mdash; the
6128first element of which is the subtraction, and the second element of which is a bit
6129specifying if the unsigned subtraction resulted in an overflow.</p>
6130
6131<h5>Examples:</h5>
6132<pre>
6133 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6134 %sum = extractvalue {i32, i1} %res, 0
6135 %obit = extractvalue {i32, i1} %res, 1
6136 br i1 %obit, label %overflow, label %normal
6137</pre>
6138
6139</div>
6140
6141<!-- _______________________________________________________________________ -->
6142<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6143 <a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6144</div>
6145
6146<div class="doc_text">
6147
6148<h5>Syntax:</h5>
6149
6150<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]6151on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6152
6153<pre>
6154 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6155 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6156 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6157</pre>
6158
6159<h5>Overview:</h5>
6160
6161<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
6162a signed multiplication of the two arguments, and indicate whether an overflow
6163occurred during the signed multiplication.</p>
6164
6165<h5>Arguments:</h5>
6166
6167<p>The arguments (%a and %b) and the first element of the result structure may
6168be of integer types of any bit width, but they must have the same bit width. The
6169second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
6170and <tt>%b</tt> are the two values that will undergo signed multiplication.</p>
6171
6172<h5>Semantics:</h5>
6173
6174<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
6175a signed multiplication of the two arguments. They return a structure &mdash;
6176the first element of which is the multiplication, and the second element of
6177which is a bit specifying if the signed multiplication resulted in an
6178overflow.</p>
6179
6180<h5>Examples:</h5>
6181<pre>
6182 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6183 %sum = extractvalue {i32, i1} %res, 0
6184 %obit = extractvalue {i32, i1} %res, 1
6185 br i1 %obit, label %overflow, label %normal
6186</pre>
6187
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]6188</div>
6189
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6190<!-- _______________________________________________________________________ -->
6191<div class="doc_subsubsection">
6192 <a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
6193</div>
6194
6195<div class="doc_text">
6196
6197<h5>Syntax:</h5>
6198
6199<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
6200on any integer bit width.</p>
6201
6202<pre>
6203 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6204 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6205 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6206</pre>
6207
6208<h5>Overview:</h5>
6209
6210<p><i><b>Warning:</b> '<tt>llvm.umul.with.overflow</tt>' is badly broken. It is
6211actively being fixed, but it should not currently be used!</i></p>
6212
6213<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
6214a unsigned multiplication of the two arguments, and indicate whether an overflow
6215occurred during the unsigned multiplication.</p>
6216
6217<h5>Arguments:</h5>
6218
6219<p>The arguments (%a and %b) and the first element of the result structure may
6220be of integer types of any bit width, but they must have the same bit width. The
6221second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
6222and <tt>%b</tt> are the two values that will undergo unsigned
6223multiplication.</p>
6224
6225<h5>Semantics:</h5>
6226
6227<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
6228an unsigned multiplication of the two arguments. They return a structure &mdash;
6229the first element of which is the multiplication, and the second element of
6230which is a bit specifying if the unsigned multiplication resulted in an
6231overflow.</p>
6232
6233<h5>Examples:</h5>
6234<pre>
6235 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6236 %sum = extractvalue {i32, i1} %res, 0
6237 %obit = extractvalue {i32, i1} %res, 1
6238 br i1 %obit, label %overflow, label %normal
6239</pre>
6240
6241</div>
6242
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6243<!-- ======================================================================= -->
6244<div class="doc_subsection">
6245 <a name="int_debugger">Debugger Intrinsics</a>
6246</div>
6247
6248<div class="doc_text">
6249<p>
6250The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
6251are described in the <a
6252href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
6253Debugging</a> document.
6254</p>
6255</div>
6256
6257
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6258<!-- ======================================================================= -->
6259<div class="doc_subsection">
6260 <a name="int_eh">Exception Handling Intrinsics</a>
6261</div>
6262
6263<div class="doc_text">
6264<p> The LLVM exception handling intrinsics (which all start with
6265<tt>llvm.eh.</tt> prefix), are described in the <a
6266href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
6267Handling</a> document. </p>
6268</div>
6269
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6270<!-- ======================================================================= -->
6271<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6272 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6273</div>
6274
6275<div class="doc_text">
6276<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6277 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6278 the <tt>nest</tt> attribute, from a function. The result is a callable
6279 function pointer lacking the nest parameter - the caller does not need
6280 to provide a value for it. Instead, the value to use is stored in
6281 advance in a "trampoline", a block of memory usually allocated
6282 on the stack, which also contains code to splice the nest value into the
6283 argument list. This is used to implement the GCC nested function address
6284 extension.
6285</p>
6286<p>
6287 For example, if the function is
6288 <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]6289 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]6290<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6291 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
6292 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
6293 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
6294 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6295</pre>
Bill Wendling03295ca2007-09-22 09:23:55 +0000[diff] [blame]6296 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
6297 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6298</div>
6299
6300<!-- _______________________________________________________________________ -->
6301<div class="doc_subsubsection">
6302 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
6303</div>
6304<div class="doc_text">
6305<h5>Syntax:</h5>
6306<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6307declare 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]6308</pre>
6309<h5>Overview:</h5>
6310<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6311 This fills the memory pointed to by <tt>tramp</tt> with code
6312 and returns a function pointer suitable for executing it.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6313</p>
6314<h5>Arguments:</h5>
6315<p>
6316 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
6317 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
6318 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsc00c2ba2007-08-22 23:39:54 +0000[diff] [blame]6319 intrinsic. Note that the size and the alignment are target-specific - LLVM
6320 currently provides no portable way of determining them, so a front-end that
6321 generates this intrinsic needs to have some target-specific knowledge.
6322 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]6323</p>
6324<h5>Semantics:</h5>
6325<p>
6326 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6327 dependent code, turning it into a function. A pointer to this function is
6328 returned, but needs to be bitcast to an
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6329 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6330 before being called. The new function's signature is the same as that of
6331 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
6332 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
6333 of pointer type. Calling the new function is equivalent to calling
6334 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
6335 missing <tt>nest</tt> argument. If, after calling
6336 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
6337 modified, then the effect of any later call to the returned function pointer is
6338 undefined.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6339</p>
6340</div>
6341
6342<!-- ======================================================================= -->
6343<div class="doc_subsection">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6344 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
6345</div>
6346
6347<div class="doc_text">
6348<p>
6349 These intrinsic functions expand the "universal IR" of LLVM to represent
6350 hardware constructs for atomic operations and memory synchronization. This
6351 provides an interface to the hardware, not an interface to the programmer. It
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]6352 is aimed at a low enough level to allow any programming models or APIs
6353 (Application Programming Interfaces) which
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6354 need atomic behaviors to map cleanly onto it. It is also modeled primarily on
6355 hardware behavior. Just as hardware provides a "universal IR" for source
6356 languages, it also provides a starting point for developing a "universal"
6357 atomic operation and synchronization IR.
6358</p>
6359<p>
6360 These do <em>not</em> form an API such as high-level threading libraries,
6361 software transaction memory systems, atomic primitives, and intrinsic
6362 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
6363 application libraries. The hardware interface provided by LLVM should allow
6364 a clean implementation of all of these APIs and parallel programming models.
6365 No one model or paradigm should be selected above others unless the hardware
6366 itself ubiquitously does so.
6367
6368</p>
6369</div>
6370
6371<!-- _______________________________________________________________________ -->
6372<div class="doc_subsubsection">
6373 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
6374</div>
6375<div class="doc_text">
6376<h5>Syntax:</h5>
6377<pre>
6378declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;,
6379i1 &lt;device&gt; )
6380
6381</pre>
6382<h5>Overview:</h5>
6383<p>
6384 The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
6385 specific pairs of memory access types.
6386</p>
6387<h5>Arguments:</h5>
6388<p>
6389 The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
6390 The first four arguments enables a specific barrier as listed below. The fith
6391 argument specifies that the barrier applies to io or device or uncached memory.
6392
6393</p>
6394 <ul>
6395 <li><tt>ll</tt>: load-load barrier</li>
6396 <li><tt>ls</tt>: load-store barrier</li>
6397 <li><tt>sl</tt>: store-load barrier</li>
6398 <li><tt>ss</tt>: store-store barrier</li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6399 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6400 </ul>
6401<h5>Semantics:</h5>
6402<p>
6403 This intrinsic causes the system to enforce some ordering constraints upon
6404 the loads and stores of the program. This barrier does not indicate
6405 <em>when</em> any events will occur, it only enforces an <em>order</em> in
6406 which they occur. For any of the specified pairs of load and store operations
6407 (f.ex. load-load, or store-load), all of the first operations preceding the
6408 barrier will complete before any of the second operations succeeding the
6409 barrier begin. Specifically the semantics for each pairing is as follows:
6410</p>
6411 <ul>
6412 <li><tt>ll</tt>: All loads before the barrier must complete before any load
6413 after the barrier begins.</li>
6414
6415 <li><tt>ls</tt>: All loads before the barrier must complete before any
6416 store after the barrier begins.</li>
6417 <li><tt>ss</tt>: All stores before the barrier must complete before any
6418 store after the barrier begins.</li>
6419 <li><tt>sl</tt>: All stores before the barrier must complete before any
6420 load after the barrier begins.</li>
6421 </ul>
6422<p>
6423 These semantics are applied with a logical "and" behavior when more than one
6424 is enabled in a single memory barrier intrinsic.
6425</p>
6426<p>
6427 Backends may implement stronger barriers than those requested when they do not
6428 support as fine grained a barrier as requested. Some architectures do not
6429 need all types of barriers and on such architectures, these become noops.
6430</p>
6431<h5>Example:</h5>
6432<pre>
6433%ptr = malloc i32
6434 store i32 4, %ptr
6435
6436%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
6437 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
6438 <i>; guarantee the above finishes</i>
6439 store i32 8, %ptr <i>; before this begins</i>
6440</pre>
6441</div>
6442
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6443<!-- _______________________________________________________________________ -->
6444<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6445 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6446</div>
6447<div class="doc_text">
6448<h5>Syntax:</h5>
6449<p>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6450 This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
6451 any integer bit width and for different address spaces. Not all targets
6452 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6453
6454<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6455declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6456declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6457declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
6458declare 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]6459
6460</pre>
6461<h5>Overview:</h5>
6462<p>
6463 This loads a value in memory and compares it to a given value. If they are
6464 equal, it stores a new value into the memory.
6465</p>
6466<h5>Arguments:</h5>
6467<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6468 The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6469 well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
6470 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
6471 this integer type. While any bit width integer may be used, targets may only
6472 lower representations they support in hardware.
6473
6474</p>
6475<h5>Semantics:</h5>
6476<p>
6477 This entire intrinsic must be executed atomically. It first loads the value
6478 in memory pointed to by <tt>ptr</tt> and compares it with the value
6479 <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
6480 loaded value is yielded in all cases. This provides the equivalent of an
6481 atomic compare-and-swap operation within the SSA framework.
6482</p>
6483<h5>Examples:</h5>
6484
6485<pre>
6486%ptr = malloc i32
6487 store i32 4, %ptr
6488
6489%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6490%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6491 <i>; yields {i32}:result1 = 4</i>
6492%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6493%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6494
6495%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6496%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6497 <i>; yields {i32}:result2 = 8</i>
6498%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6499
6500%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6501</pre>
6502</div>
6503
6504<!-- _______________________________________________________________________ -->
6505<div class="doc_subsubsection">
6506 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6507</div>
6508<div class="doc_text">
6509<h5>Syntax:</h5>
6510
6511<p>
6512 This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6513 integer bit width. Not all targets support all bit widths however.</p>
6514<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6515declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6516declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6517declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6518declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6519
6520</pre>
6521<h5>Overview:</h5>
6522<p>
6523 This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6524 the value from memory. It then stores the value in <tt>val</tt> in the memory
6525 at <tt>ptr</tt>.
6526</p>
6527<h5>Arguments:</h5>
6528
6529<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6530 The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6531 <tt>val</tt> argument and the result must be integers of the same bit width.
6532 The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6533 integer type. The targets may only lower integer representations they
6534 support.
6535</p>
6536<h5>Semantics:</h5>
6537<p>
6538 This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6539 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6540 equivalent of an atomic swap operation within the SSA framework.
6541
6542</p>
6543<h5>Examples:</h5>
6544<pre>
6545%ptr = malloc i32
6546 store i32 4, %ptr
6547
6548%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6549%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6550 <i>; yields {i32}:result1 = 4</i>
6551%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6552%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6553
6554%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6555%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6556 <i>; yields {i32}:result2 = 8</i>
6557
6558%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6559%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6560</pre>
6561</div>
6562
6563<!-- _______________________________________________________________________ -->
6564<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6565 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6566
6567</div>
6568<div class="doc_text">
6569<h5>Syntax:</h5>
6570<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6571 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]6572 integer bit width. Not all targets support all bit widths however.</p>
6573<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6574declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6575declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6576declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6577declare 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]6578
6579</pre>
6580<h5>Overview:</h5>
6581<p>
6582 This intrinsic adds <tt>delta</tt> to the value stored in memory at
6583 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6584</p>
6585<h5>Arguments:</h5>
6586<p>
6587
6588 The intrinsic takes two arguments, the first a pointer to an integer value
6589 and the second an integer value. The result is also an integer value. These
6590 integer types can have any bit width, but they must all have the same bit
6591 width. The targets may only lower integer representations they support.
6592</p>
6593<h5>Semantics:</h5>
6594<p>
6595 This intrinsic does a series of operations atomically. It first loads the
6596 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6597 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6598</p>
6599
6600<h5>Examples:</h5>
6601<pre>
6602%ptr = malloc i32
6603 store i32 4, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6604%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6605 <i>; yields {i32}:result1 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6606%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6607 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6608%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6609 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6610%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6611</pre>
6612</div>
6613
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6614<!-- _______________________________________________________________________ -->
6615<div class="doc_subsubsection">
6616 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6617
6618</div>
6619<div class="doc_text">
6620<h5>Syntax:</h5>
6621<p>
6622 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]6623 any integer bit width and for different address spaces. Not all targets
6624 support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6625<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6626declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6627declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6628declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6629declare 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]6630
6631</pre>
6632<h5>Overview:</h5>
6633<p>
6634 This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6635 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6636</p>
6637<h5>Arguments:</h5>
6638<p>
6639
6640 The intrinsic takes two arguments, the first a pointer to an integer value
6641 and the second an integer value. The result is also an integer value. These
6642 integer types can have any bit width, but they must all have the same bit
6643 width. The targets may only lower integer representations they support.
6644</p>
6645<h5>Semantics:</h5>
6646<p>
6647 This intrinsic does a series of operations atomically. It first loads the
6648 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6649 result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6650</p>
6651
6652<h5>Examples:</h5>
6653<pre>
6654%ptr = malloc i32
6655 store i32 8, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6656%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6657 <i>; yields {i32}:result1 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6658%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6659 <i>; yields {i32}:result2 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6660%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6661 <i>; yields {i32}:result3 = 2</i>
6662%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6663</pre>
6664</div>
6665
6666<!-- _______________________________________________________________________ -->
6667<div class="doc_subsubsection">
6668 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6669 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6670 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6671 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
6672
6673</div>
6674<div class="doc_text">
6675<h5>Syntax:</h5>
6676<p>
6677 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
6678 <tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6679 <tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
6680 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6681<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6682declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6683declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6684declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6685declare 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]6686
6687</pre>
6688
6689<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6690declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6691declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6692declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6693declare 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]6694
6695</pre>
6696
6697<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6698declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6699declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6700declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6701declare 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]6702
6703</pre>
6704
6705<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6706declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6707declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6708declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6709declare 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]6710
6711</pre>
6712<h5>Overview:</h5>
6713<p>
6714 These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6715 the value stored in memory at <tt>ptr</tt>. It yields the original value
6716 at <tt>ptr</tt>.
6717</p>
6718<h5>Arguments:</h5>
6719<p>
6720
6721 These intrinsics take two arguments, the first a pointer to an integer value
6722 and the second an integer value. The result is also an integer value. These
6723 integer types can have any bit width, but they must all have the same bit
6724 width. The targets may only lower integer representations they support.
6725</p>
6726<h5>Semantics:</h5>
6727<p>
6728 These intrinsics does a series of operations atomically. They first load the
6729 value stored at <tt>ptr</tt>. They then do the bitwise operation
6730 <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
6731 value stored at <tt>ptr</tt>.
6732</p>
6733
6734<h5>Examples:</h5>
6735<pre>
6736%ptr = malloc i32
6737 store i32 0x0F0F, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6738%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6739 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6740%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6741 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6742%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6743 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6744%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6745 <i>; yields {i32}:result3 = FF</i>
6746%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6747</pre>
6748</div>
6749
6750
6751<!-- _______________________________________________________________________ -->
6752<div class="doc_subsubsection">
6753 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6754 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6755 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6756 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
6757
6758</div>
6759<div class="doc_text">
6760<h5>Syntax:</h5>
6761<p>
6762 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6763 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6764 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6765 address spaces. Not all targets
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6766 support all bit widths however.</p>
6767<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6768declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6769declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6770declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6771declare 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]6772
6773</pre>
6774
6775<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6776declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6777declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6778declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6779declare i64 @llvm.atomic.load.min.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6780
6781</pre>
6782
6783<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6784declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6785declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6786declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6787declare 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]6788
6789</pre>
6790
6791<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6792declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6793declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6794declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6795declare 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]6796
6797</pre>
6798<h5>Overview:</h5>
6799<p>
6800 These intrinsics takes the signed or unsigned minimum or maximum of
6801 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6802 original value at <tt>ptr</tt>.
6803</p>
6804<h5>Arguments:</h5>
6805<p>
6806
6807 These intrinsics take two arguments, the first a pointer to an integer value
6808 and the second an integer value. The result is also an integer value. These
6809 integer types can have any bit width, but they must all have the same bit
6810 width. The targets may only lower integer representations they support.
6811</p>
6812<h5>Semantics:</h5>
6813<p>
6814 These intrinsics does a series of operations atomically. They first load the
6815 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
6816 <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
6817 the original value stored at <tt>ptr</tt>.
6818</p>
6819
6820<h5>Examples:</h5>
6821<pre>
6822%ptr = malloc i32
6823 store i32 7, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6824%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6825 <i>; yields {i32}:result0 = 7</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6826%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6827 <i>; yields {i32}:result1 = -2</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6828%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6829 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6830%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6831 <i>; yields {i32}:result3 = 8</i>
6832%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6833</pre>
6834</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6835
6836<!-- ======================================================================= -->
6837<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6838 <a name="int_general">General Intrinsics</a>
6839</div>
6840
6841<div class="doc_text">
6842<p> This class of intrinsics is designed to be generic and has
6843no specific purpose. </p>
6844</div>
6845
6846<!-- _______________________________________________________________________ -->
6847<div class="doc_subsubsection">
6848 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6849</div>
6850
6851<div class="doc_text">
6852
6853<h5>Syntax:</h5>
6854<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]6855 declare void @llvm.var.annotation(i8* &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6856</pre>
6857
6858<h5>Overview:</h5>
6859
6860<p>
6861The '<tt>llvm.var.annotation</tt>' intrinsic
6862</p>
6863
6864<h5>Arguments:</h5>
6865
6866<p>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]6867The first argument is a pointer to a value, the second is a pointer to a
6868global string, the third is a pointer to a global string which is the source
6869file name, and the last argument is the line number.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6870</p>
6871
6872<h5>Semantics:</h5>
6873
6874<p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6875This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6876This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6877annotations. These have no other defined use, they are ignored by code
6878generation and optimization.
6879</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6880</div>
6881
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6882<!-- _______________________________________________________________________ -->
6883<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]6884 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6885</div>
6886
6887<div class="doc_text">
6888
6889<h5>Syntax:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6890<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6891any integer bit width.
6892</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6893<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]6894 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6895 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6896 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6897 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6898 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]6899</pre>
6900
6901<h5>Overview:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6902
6903<p>
6904The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6905</p>
6906
6907<h5>Arguments:</h5>
6908
6909<p>
6910The first argument is an integer value (result of some expression),
6911the second is a pointer to a global string, the third is a pointer to a global
6912string which is the source file name, and the last argument is the line number.
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6913It returns the value of the first argument.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6914</p>
6915
6916<h5>Semantics:</h5>
6917
6918<p>
6919This intrinsic allows annotations to be put on arbitrary expressions
6920with arbitrary strings. This can be useful for special purpose optimizations
6921that want to look for these annotations. These have no other defined use, they
6922are ignored by code generation and optimization.
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6923</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6924</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6925
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6926<!-- _______________________________________________________________________ -->
6927<div class="doc_subsubsection">
6928 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6929</div>
6930
6931<div class="doc_text">
6932
6933<h5>Syntax:</h5>
6934<pre>
6935 declare void @llvm.trap()
6936</pre>
6937
6938<h5>Overview:</h5>
6939
6940<p>
6941The '<tt>llvm.trap</tt>' intrinsic
6942</p>
6943
6944<h5>Arguments:</h5>
6945
6946<p>
6947None
6948</p>
6949
6950<h5>Semantics:</h5>
6951
6952<p>
6953This intrinsics is lowered to the target dependent trap instruction. If the
6954target does not have a trap instruction, this intrinsic will be lowered to the
6955call of the abort() function.
6956</p>
6957</div>
6958
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6959<!-- _______________________________________________________________________ -->
6960<div class="doc_subsubsection">
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]6961 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6962</div>
6963<div class="doc_text">
6964<h5>Syntax:</h5>
6965<pre>
6966declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
6967
6968</pre>
6969<h5>Overview:</h5>
6970<p>
6971 The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
6972 it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
6973 it is placed on the stack before local variables.
6974</p>
6975<h5>Arguments:</h5>
6976<p>
6977 The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
6978 first argument is the value loaded from the stack guard
6979 <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
6980 has enough space to hold the value of the guard.
6981</p>
6982<h5>Semantics:</h5>
6983<p>
6984 This intrinsic causes the prologue/epilogue inserter to force the position of
6985 the <tt>AllocaInst</tt> stack slot to be before local variables on the
6986 stack. This is to ensure that if a local variable on the stack is overwritten,
6987 it will destroy the value of the guard. When the function exits, the guard on
6988 the stack is checked against the original guard. If they're different, then
6989 the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
6990</p>
6991</div>
6992
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6993<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6994<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6995<address>
6996 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]6997 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6998 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]6999 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]7000
7001 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]7002 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]7003 Last modified: $Date$
7004</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]7005
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]7006</body>
7007</html>