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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / b805030e02452b9724aafca5ad7a30c66e6e357c / . / 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>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]212 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]213 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]214 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]215 <ol>
216 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]217 </ol>
218 </li>
Bill Wendling3c44f5b2008-11-18 22:10:53 +0000[diff] [blame]219 <li><a href="#int_atomics">Atomic intrinsics</a>
220 <ol>
221 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
222 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
223 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
224 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
225 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
226 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
227 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
228 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
229 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
230 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
231 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
232 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
233 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
234 </ol>
235 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]236 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]237 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]238 <li><a href="#int_var_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]239 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]240 <li><a href="#int_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]241 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]242 <li><a href="#int_trap">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]243 '<tt>llvm.trap</tt>' Intrinsic</a></li>
244 <li><a href="#int_stackprotector">
245 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]246 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]247 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]248 </ol>
249 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]250</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]251
252<div class="doc_author">
253 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
254 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]255</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]256
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]257<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]258<div class="doc_section"> <a name="abstract">Abstract </a></div>
259<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]260
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]261<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]262<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling837f39b2008-08-05 22:29:16 +0000[diff] [blame]263LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]264type safety, low-level operations, flexibility, and the capability of
265representing 'all' high-level languages cleanly. It is the common code
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]266representation used throughout all phases of the LLVM compilation
267strategy.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]268</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]269
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]270<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]271<div class="doc_section"> <a name="introduction">Introduction</a> </div>
272<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]273
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]274<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]275
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]276<p>The LLVM code representation is designed to be used in three
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]277different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]278representation (suitable for fast loading by a Just-In-Time compiler),
279and as a human readable assembly language representation. This allows
280LLVM to provide a powerful intermediate representation for efficient
281compiler transformations and analysis, while providing a natural means
282to debug and visualize the transformations. The three different forms
283of LLVM are all equivalent. This document describes the human readable
284representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]285
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]286<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]287while being expressive, typed, and extensible at the same time. It
288aims to be a "universal IR" of sorts, by being at a low enough level
289that high-level ideas may be cleanly mapped to it (similar to how
290microprocessors are "universal IR's", allowing many source languages to
291be mapped to them). By providing type information, LLVM can be used as
292the target of optimizations: for example, through pointer analysis, it
293can be proven that a C automatic variable is never accessed outside of
294the current function... allowing it to be promoted to a simple SSA
295value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]296
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]297</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]298
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]299<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]300<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]301
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]302<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]303
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]304<p>It is important to note that this document describes 'well formed'
305LLVM assembly language. There is a difference between what the parser
306accepts and what is considered 'well formed'. For example, the
307following instruction is syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]308
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]309<div class="doc_code">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]310<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]311%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]312</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]313</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]314
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]315<p>...because the definition of <tt>%x</tt> does not dominate all of
316its uses. The LLVM infrastructure provides a verification pass that may
317be used to verify that an LLVM module is well formed. This pass is
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]318automatically run by the parser after parsing input assembly and by
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]319the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]320by the verifier pass indicate bugs in transformation passes or input to
321the parser.</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]322</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]323
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]324<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]325
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]326<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]327<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]328<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]329
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]330<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]331
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]332 <p>LLVM identifiers come in two basic types: global and local. Global
333 identifiers (functions, global variables) begin with the @ character. Local
334 identifiers (register names, types) begin with the % character. Additionally,
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]335 there are three different formats for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]336
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]337<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]338 <li>Named values are represented as a string of characters with their prefix.
339 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
340 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]341 Identifiers which require other characters in their names can be surrounded
Daniel Dunbar76dea952008-10-14 23:51:43 +0000[diff] [blame]342 with quotes. Special characters may be escaped using "\xx" where xx is the
343 ASCII code for the character in hexadecimal. In this way, any character can
344 be used in a name value, even quotes themselves.
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]345
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]346 <li>Unnamed values are represented as an unsigned numeric value with their
347 prefix. For example, %12, @2, %44.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]348
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]349 <li>Constants, which are described in a <a href="#constants">section about
350 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]351</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]352
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]353<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]354don't need to worry about name clashes with reserved words, and the set of
355reserved words may be expanded in the future without penalty. Additionally,
356unnamed identifiers allow a compiler to quickly come up with a temporary
357variable without having to avoid symbol table conflicts.</p>
358
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]359<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]360languages. There are keywords for different opcodes
361('<tt><a href="#i_add">add</a></tt>',
362 '<tt><a href="#i_bitcast">bitcast</a></tt>',
363 '<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]364href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]365and others. These reserved words cannot conflict with variable names, because
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]366none of them start with a prefix character ('%' or '@').</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]367
368<p>Here is an example of LLVM code to multiply the integer variable
369'<tt>%X</tt>' by 8:</p>
370
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]371<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]372
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]373<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]374<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]375%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]376</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]377</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]378
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]379<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]380
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]381<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]382<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]383%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]384</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]385</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]386
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]387<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]388
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]389<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]390<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]391<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
392<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
393%result = <a href="#i_add">add</a> i32 %1, %1
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
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]397<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
398important lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]399
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]400<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]401
402 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
403 line.</li>
404
405 <li>Unnamed temporaries are created when the result of a computation is not
406 assigned to a named value.</li>
407
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]408 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]409
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]410</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]411
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]412<p>...and it also shows a convention that we follow in this document. When
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]413demonstrating instructions, we will follow an instruction with a comment that
414defines the type and name of value produced. Comments are shown in italic
415text.</p>
416
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]417</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]418
419<!-- *********************************************************************** -->
420<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
421<!-- *********************************************************************** -->
422
423<!-- ======================================================================= -->
424<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
425</div>
426
427<div class="doc_text">
428
429<p>LLVM programs are composed of "Module"s, each of which is a
430translation unit of the input programs. Each module consists of
431functions, global variables, and symbol table entries. Modules may be
432combined together with the LLVM linker, which merges function (and
433global variable) definitions, resolves forward declarations, and merges
434symbol table entries. Here is an example of the "hello world" module:</p>
435
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]436<div class="doc_code">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]437<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]438<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
439 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]440
441<i>; External declaration of the puts function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]442<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]443
444<i>; Definition of main function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]445define i32 @main() { <i>; i32()* </i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]446 <i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]447 %cast210 = <a
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]448 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]449
450 <i>; Call puts function to write out the string to stdout...</i>
451 <a
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]452 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]453 <a
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]454 href="#i_ret">ret</a> i32 0<br>}<br>
455</pre>
456</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]457
458<p>This example is made up of a <a href="#globalvars">global variable</a>
459named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
460function, and a <a href="#functionstructure">function definition</a>
461for "<tt>main</tt>".</p>
462
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]463<p>In general, a module is made up of a list of global values,
464where both functions and global variables are global values. Global values are
465represented by a pointer to a memory location (in this case, a pointer to an
466array of char, and a pointer to a function), and have one of the following <a
467href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]468
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]469</div>
470
471<!-- ======================================================================= -->
472<div class="doc_subsection">
473 <a name="linkage">Linkage Types</a>
474</div>
475
476<div class="doc_text">
477
478<p>
479All Global Variables and Functions have one of the following types of linkage:
480</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]481
482<dl>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]483
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]484 <dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
485
486 <dd>Global values with private linkage are only directly accessible by
487 objects in the current module. In particular, linking code into a module with
488 an private global value may cause the private to be renamed as necessary to
489 avoid collisions. Because the symbol is private to the module, all
490 references can be updated. This doesn't show up in any symbol table in the
491 object file.
492 </dd>
493
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]494 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]495
Duncan Sands81d05c22009-01-16 09:29:46 +0000[diff] [blame]496 <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]497 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]498 '<tt>static</tt>' keyword in C.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]499 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]500
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]501 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]502
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]503 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
504 the same name when linkage occurs. This is typically used to implement
505 inline functions, templates, or other code which must be generated in each
506 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
507 allowed to be discarded.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]508 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]509
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]510 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
511
512 <dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
513 linkage, except that unreferenced <tt>common</tt> globals may not be
514 discarded. This is used for globals that may be emitted in multiple
515 translation units, but that are not guaranteed to be emitted into every
516 translation unit that uses them. One example of this is tentative
517 definitions in C, such as "<tt>int X;</tt>" at global scope.
518 </dd>
519
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]520 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]521
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]522 <dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
523 that some targets may choose to emit different assembly sequences for them
524 for target-dependent reasons. This is used for globals that are declared
525 "weak" in C source code.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]526 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]527
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]528 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]529
530 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
531 pointer to array type. When two global variables with appending linkage are
532 linked together, the two global arrays are appended together. This is the
533 LLVM, typesafe, equivalent of having the system linker append together
534 "sections" with identical names when .o files are linked.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]535 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]536
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]537 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]538 <dd>The semantics of this linkage follow the ELF object file model: the
539 symbol is weak until linked, if not linked, the symbol becomes null instead
540 of being an undefined reference.
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]541 </dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]542
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]543 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]544
545 <dd>If none of the above identifiers are used, the global is externally
546 visible, meaning that it participates in linkage and can be used to resolve
547 external symbol references.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]548 </dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]549</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]550
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]551 <p>
552 The next two types of linkage are targeted for Microsoft Windows platform
553 only. They are designed to support importing (exporting) symbols from (to)
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]554 DLLs (Dynamic Link Libraries).
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]555 </p>
556
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]557 <dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]558 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
559
560 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
561 or variable via a global pointer to a pointer that is set up by the DLL
562 exporting the symbol. On Microsoft Windows targets, the pointer name is
Dan Gohman79564122009-01-12 21:35:55 +0000[diff] [blame]563 formed by combining <code>__imp_</code> and the function or variable name.
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]564 </dd>
565
566 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
567
568 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
569 pointer to a pointer in a DLL, so that it can be referenced with the
570 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
Dan Gohman79564122009-01-12 21:35:55 +0000[diff] [blame]571 name is formed by combining <code>__imp_</code> and the function or variable
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]572 name.
573 </dd>
574
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]575</dl>
576
Dan Gohmanf0032762008-11-24 17:18:39 +0000[diff] [blame]577<p>For example, since the "<tt>.LC0</tt>"
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]578variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
579variable and was linked with this one, one of the two would be renamed,
580preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
581external (i.e., lacking any linkage declarations), they are accessible
Reid Spencerac8d2762007-01-05 00:59:10 +0000[diff] [blame]582outside of the current module.</p>
583<p>It is illegal for a function <i>declaration</i>
584to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]585or <tt>extern_weak</tt>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]586<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]587linkages.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]588</div>
589
590<!-- ======================================================================= -->
591<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]592 <a name="callingconv">Calling Conventions</a>
593</div>
594
595<div class="doc_text">
596
597<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
598and <a href="#i_invoke">invokes</a> can all have an optional calling convention
599specified for the call. The calling convention of any pair of dynamic
600caller/callee must match, or the behavior of the program is undefined. The
601following calling conventions are supported by LLVM, and more may be added in
602the future:</p>
603
604<dl>
605 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
606
607 <dd>This calling convention (the default if no other calling convention is
608 specified) matches the target C calling conventions. This calling convention
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]609 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencerc28d2bc2006-12-31 21:30:18 +0000[diff] [blame]610 prototype and implemented declaration of the function (as does normal C).
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]611 </dd>
612
613 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
614
615 <dd>This calling convention attempts to make calls as fast as possible
616 (e.g. by passing things in registers). This calling convention allows the
617 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]618 without having to conform to an externally specified ABI (Application Binary
619 Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer9097d142008-05-14 09:17:12 +0000[diff] [blame]620 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
621 supported. This calling convention does not support varargs and requires the
622 prototype of all callees to exactly match the prototype of the function
623 definition.
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]624 </dd>
625
626 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
627
628 <dd>This calling convention attempts to make code in the caller as efficient
629 as possible under the assumption that the call is not commonly executed. As
630 such, these calls often preserve all registers so that the call does not break
631 any live ranges in the caller side. This calling convention does not support
632 varargs and requires the prototype of all callees to exactly match the
633 prototype of the function definition.
634 </dd>
635
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]636 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]637
638 <dd>Any calling convention may be specified by number, allowing
639 target-specific calling conventions to be used. Target specific calling
640 conventions start at 64.
641 </dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]642</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]643
644<p>More calling conventions can be added/defined on an as-needed basis, to
645support pascal conventions or any other well-known target-independent
646convention.</p>
647
648</div>
649
650<!-- ======================================================================= -->
651<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]652 <a name="visibility">Visibility Styles</a>
653</div>
654
655<div class="doc_text">
656
657<p>
658All Global Variables and Functions have one of the following visibility styles:
659</p>
660
661<dl>
662 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
663
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]664 <dd>On targets that use the ELF object file format, default visibility means
665 that the declaration is visible to other
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]666 modules and, in shared libraries, means that the declared entity may be
667 overridden. On Darwin, default visibility means that the declaration is
668 visible to other modules. Default visibility corresponds to "external
669 linkage" in the language.
670 </dd>
671
672 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
673
674 <dd>Two declarations of an object with hidden visibility refer to the same
675 object if they are in the same shared object. Usually, hidden visibility
676 indicates that the symbol will not be placed into the dynamic symbol table,
677 so no other module (executable or shared library) can reference it
678 directly.
679 </dd>
680
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]681 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
682
683 <dd>On ELF, protected visibility indicates that the symbol will be placed in
684 the dynamic symbol table, but that references within the defining module will
685 bind to the local symbol. That is, the symbol cannot be overridden by another
686 module.
687 </dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]688</dl>
689
690</div>
691
692<!-- ======================================================================= -->
693<div class="doc_subsection">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]694 <a name="namedtypes">Named Types</a>
695</div>
696
697<div class="doc_text">
698
699<p>LLVM IR allows you to specify name aliases for certain types. This can make
700it easier to read the IR and make the IR more condensed (particularly when
701recursive types are involved). An example of a name specification is:
702</p>
703
704<div class="doc_code">
705<pre>
706%mytype = type { %mytype*, i32 }
707</pre>
708</div>
709
710<p>You may give a name to any <a href="#typesystem">type</a> except "<a
711href="t_void">void</a>". Type name aliases may be used anywhere a type is
712expected with the syntax "%mytype".</p>
713
714<p>Note that type names are aliases for the structural type that they indicate,
715and that you can therefore specify multiple names for the same type. This often
716leads to confusing behavior when dumping out a .ll file. Since LLVM IR uses
717structural typing, the name is not part of the type. When printing out LLVM IR,
718the printer will pick <em>one name</em> to render all types of a particular
719shape. This means that if you have code where two different source types end up
720having the same LLVM type, that the dumper will sometimes print the "wrong" or
721unexpected type. This is an important design point and isn't going to
722change.</p>
723
724</div>
725
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]726<!-- ======================================================================= -->
727<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]728 <a name="globalvars">Global Variables</a>
729</div>
730
731<div class="doc_text">
732
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]733<p>Global variables define regions of memory allocated at compilation time
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]734instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]735an explicit section to be placed in, and may have an optional explicit alignment
736specified. A variable may be defined as "thread_local", which means that it
737will not be shared by threads (each thread will have a separated copy of the
738variable). A variable may be defined as a global "constant," which indicates
739that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]740optimization, allowing the global data to be placed in the read-only section of
741an executable, etc). Note that variables that need runtime initialization
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]742cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]743
744<p>
745LLVM explicitly allows <em>declarations</em> of global variables to be marked
746constant, even if the final definition of the global is not. This capability
747can be used to enable slightly better optimization of the program, but requires
748the language definition to guarantee that optimizations based on the
749'constantness' are valid for the translation units that do not include the
750definition.
751</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]752
753<p>As SSA values, global variables define pointer values that are in
754scope (i.e. they dominate) all basic blocks in the program. Global
755variables always define a pointer to their "content" type because they
756describe a region of memory, and all memory objects in LLVM are
757accessed through pointers.</p>
758
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]759<p>A global variable may be declared to reside in a target-specifc numbered
760address space. For targets that support them, address spaces may affect how
761optimizations are performed and/or what target instructions are used to access
Christopher Lambd49e18d2007-12-12 08:44:39 +0000[diff] [blame]762the variable. The default address space is zero. The address space qualifier
763must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]764
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]765<p>LLVM allows an explicit section to be specified for globals. If the target
766supports it, it will emit globals to the section specified.</p>
767
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]768<p>An explicit alignment may be specified for a global. If not present, or if
769the alignment is set to zero, the alignment of the global is set by the target
770to whatever it feels convenient. If an explicit alignment is specified, the
771global is forced to have at least that much alignment. All alignments must be
772a power of 2.</p>
773
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]774<p>For example, the following defines a global in a numbered address space with
775an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]776
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]777<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]778<pre>
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]779@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]780</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]781</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]782
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]783</div>
784
785
786<!-- ======================================================================= -->
787<div class="doc_subsection">
788 <a name="functionstructure">Functions</a>
789</div>
790
791<div class="doc_text">
792
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]793<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
794an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]795<a href="#visibility">visibility style</a>, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]796<a href="#callingconv">calling convention</a>, a return type, an optional
797<a href="#paramattrs">parameter attribute</a> for the return type, a function
798name, a (possibly empty) argument list (each with optional
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]799<a href="#paramattrs">parameter attributes</a>), optional
800<a href="#fnattrs">function attributes</a>, an optional section,
801an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner0c46a7d2008-10-04 18:10:21 +0000[diff] [blame]802an opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]803
804LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
805optional <a href="#linkage">linkage type</a>, an optional
806<a href="#visibility">visibility style</a>, an optional
807<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]808<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]809name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksene754abe2007-12-10 03:30:21 +0000[diff] [blame]810<a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]811
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]812<p>A function definition contains a list of basic blocks, forming the CFG
813(Control Flow Graph) for
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]814the function. Each basic block may optionally start with a label (giving the
815basic block a symbol table entry), contains a list of instructions, and ends
816with a <a href="#terminators">terminator</a> instruction (such as a branch or
817function return).</p>
818
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]819<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]820executed on entrance to the function, and it is not allowed to have predecessor
821basic blocks (i.e. there can not be any branches to the entry block of a
822function). Because the block can have no predecessors, it also cannot have any
823<a href="#i_phi">PHI nodes</a>.</p>
824
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]825<p>LLVM allows an explicit section to be specified for functions. If the target
826supports it, it will emit functions to the section specified.</p>
827
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]828<p>An explicit alignment may be specified for a function. If not present, or if
829the alignment is set to zero, the alignment of the function is set by the target
830to whatever it feels convenient. If an explicit alignment is specified, the
831function is forced to have at least that much alignment. All alignments must be
832a power of 2.</p>
833
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]834 <h5>Syntax:</h5>
835
836<div class="doc_code">
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]837<tt>
838define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
839 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
840 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
841 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
842 [<a href="#gc">gc</a>] { ... }
843</tt>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]844</div>
845
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]846</div>
847
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]848
849<!-- ======================================================================= -->
850<div class="doc_subsection">
851 <a name="aliasstructure">Aliases</a>
852</div>
853<div class="doc_text">
854 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov726d45c2008-03-22 08:36:14 +0000[diff] [blame]855 function, global variable, another alias or bitcast of global value). Aliases
856 may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]857 optional <a href="#visibility">visibility style</a>.</p>
858
859 <h5>Syntax:</h5>
860
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]861<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]862<pre>
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]863@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]864</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]865</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]866
867</div>
868
869
870
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]871<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]872<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
873<div class="doc_text">
874 <p>The return type and each parameter of a function type may have a set of
875 <i>parameter attributes</i> associated with them. Parameter attributes are
876 used to communicate additional information about the result or parameters of
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]877 a function. Parameter attributes are considered to be part of the function,
878 not of the function type, so functions with different parameter attributes
879 can have the same function type.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]880
Reid Spencer950e9f82007-01-15 18:27:39 +0000[diff] [blame]881 <p>Parameter attributes are simple keywords that follow the type specified. If
882 multiple parameter attributes are needed, they are space separated. For
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]883 example:</p>
884
885<div class="doc_code">
886<pre>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]887declare i32 @printf(i8* noalias , ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]888declare i32 @atoi(i8 zeroext)
889declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]890</pre>
891</div>
892
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]893 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
894 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]895
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]896 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]897 <dl>
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]898 <dt><tt>zeroext</tt></dt>
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]899 <dd>This indicates to the code generator that the parameter or return value
900 should be zero-extended to a 32-bit value by the caller (for a parameter)
901 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]902
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]903 <dt><tt>signext</tt></dt>
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]904 <dd>This indicates to the code generator that the parameter or return value
905 should be sign-extended to a 32-bit value by the caller (for a parameter)
906 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]907
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]908 <dt><tt>inreg</tt></dt>
Dale Johannesenc9c6da62008-09-25 20:47:45 +0000[diff] [blame]909 <dd>This indicates that this parameter or return value should be treated
910 in a special target-dependent fashion during while emitting code for a
911 function call or return (usually, by putting it in a register as opposed
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]912 to memory, though some targets use it to distinguish between two different
913 kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]914
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]915 <dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner0747baa2008-01-15 04:34:22 +0000[diff] [blame]916 <dd>This indicates that the pointer parameter should really be passed by
917 value to the function. The attribute implies that a hidden copy of the
918 pointee is made between the caller and the callee, so the callee is unable
Chris Lattnerebec6782008-08-05 18:21:08 +0000[diff] [blame]919 to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner0747baa2008-01-15 04:34:22 +0000[diff] [blame]920 pointer arguments. It is generally used to pass structs and arrays by
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]921 value, but is also valid on pointers to scalars. The copy is considered to
922 belong to the caller not the callee (for example,
923 <tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]924 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattnerce459b12009-02-05 05:42:28 +0000[diff] [blame]925 values. The byval attribute also supports specifying an alignment with the
926 align attribute. This has a target-specific effect on the code generator
927 that usually indicates a desired alignment for the synthesized stack
928 slot.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]929
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]930 <dt><tt>sret</tt></dt>
Duncan Sandse26dec62008-02-18 04:19:38 +0000[diff] [blame]931 <dd>This indicates that the pointer parameter specifies the address of a
932 structure that is the return value of the function in the source program.
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]933 This pointer must be guaranteed by the caller to be valid: loads and stores
934 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]935 be applied to the first parameter. This is not a valid attribute for
936 return values. </dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]937
Zhou Shengfebca342007-06-05 05:28:26 +0000[diff] [blame]938 <dt><tt>noalias</tt></dt>
Nick Lewycky02ff3082008-11-24 03:41:24 +0000[diff] [blame]939 <dd>This indicates that the pointer does not alias any global or any other
940 parameter. The caller is responsible for ensuring that this is the
Nick Lewyckyb2b32fd2008-11-24 05:00:44 +0000[diff] [blame]941 case. On a function return value, <tt>noalias</tt> additionally indicates
942 that the pointer does not alias any other pointers visible to the
Nick Lewyckyf23d0d32008-12-19 06:39:12 +0000[diff] [blame]943 caller. For further details, please see the discussion of the NoAlias
944 response in
945 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
946 analysis</a>.</dd>
947
948 <dt><tt>nocapture</tt></dt>
949 <dd>This indicates that the callee does not make any copies of the pointer
950 that outlive the callee itself. This is not a valid attribute for return
951 values.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]952
Duncan Sands50f19f52007-07-27 19:57:41 +0000[diff] [blame]953 <dt><tt>nest</tt></dt>
Duncan Sands0789b8b2008-07-08 09:27:25 +0000[diff] [blame]954 <dd>This indicates that the pointer parameter can be excised using the
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]955 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
956 attribute for return values.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]957 </dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]958
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]959</div>
960
961<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]962<div class="doc_subsection">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]963 <a name="gc">Garbage Collector Names</a>
964</div>
965
966<div class="doc_text">
967<p>Each function may specify a garbage collector name, which is simply a
968string.</p>
969
970<div class="doc_code"><pre
971>define void @f() gc "name" { ...</pre></div>
972
973<p>The compiler declares the supported values of <i>name</i>. Specifying a
974collector which will cause the compiler to alter its output in order to support
975the named garbage collection algorithm.</p>
976</div>
977
978<!-- ======================================================================= -->
979<div class="doc_subsection">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]980 <a name="fnattrs">Function Attributes</a>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]981</div>
982
983<div class="doc_text">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]984
985<p>Function attributes are set to communicate additional information about
986 a function. Function attributes are considered to be part of the function,
987 not of the function type, so functions with different parameter attributes
988 can have the same function type.</p>
989
990 <p>Function attributes are simple keywords that follow the type specified. If
991 multiple attributes are needed, they are space separated. For
992 example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]993
994<div class="doc_code">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]995<pre>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]996define void @f() noinline { ... }
997define void @f() alwaysinline { ... }
998define void @f() alwaysinline optsize { ... }
999define void @f() optsize
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1000</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1001</div>
1002
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1003<dl>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1004<dt><tt>alwaysinline</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1005<dd>This attribute indicates that the inliner should attempt to inline this
1006function into callers whenever possible, ignoring any active inlining size
1007threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1008
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1009<dt><tt>noinline</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1010<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner94b5f7d2008-10-05 17:14:59 +0000[diff] [blame]1011in any situation. This attribute may not be used together with the
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1012<tt>alwaysinline</tt> attribute.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1013
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1014<dt><tt>optsize</tt></dt>
Devang Patel66c6c652008-09-29 18:34:44 +0000[diff] [blame]1015<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1016make choices that keep the code size of this function low, and otherwise do
1017optimizations specifically to reduce code size.</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>noreturn</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1020<dd>This function attribute indicates that the function never returns normally.
1021This produces undefined behavior at runtime if the function ever does
1022dynamically return.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1023
1024<dt><tt>nounwind</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1025<dd>This function attribute indicates that the function never returns with an
1026unwind or exceptional control flow. If the function does unwind, its runtime
1027behavior is undefined.</dd>
1028
1029<dt><tt>readnone</tt></dt>
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]1030<dd>This attribute indicates that the function computes its result (or the
1031exception it throws) based strictly on its arguments, without dereferencing any
1032pointer arguments or otherwise accessing any mutable state (e.g. memory, control
1033registers, etc) visible to caller functions. It does not write through any
1034pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
1035never changes any state visible to callers.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1036
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]1037<dt><tt><a name="readonly">readonly</a></tt></dt>
1038<dd>This attribute indicates that the function does not write through any
1039pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
1040or otherwise modify any state (e.g. memory, control registers, etc) visible to
1041caller functions. It may dereference pointer arguments and read state that may
1042be set in the caller. A readonly function always returns the same value (or
1043throws the same exception) when called with the same set of arguments and global
1044state.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1045
1046<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1047<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1048protector. It is in the form of a "canary"&mdash;a random value placed on the
1049stack before the local variables that's checked upon return from the function to
1050see if it has been overwritten. A heuristic is used to determine if a function
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1051needs stack protectors or not.
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1052
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1053<p>If a function that has an <tt>ssp</tt> attribute is inlined into a function
1054that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
1055have an <tt>ssp</tt> attribute.</p></dd>
1056
1057<dt><tt>sspreq</tt></dt>
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1058<dd>This attribute indicates that the function should <em>always</em> emit a
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1059stack smashing protector. This overrides the <tt><a href="#ssp">ssp</a></tt>
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1060function attribute.
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1061
1062<p>If a function that has an <tt>sspreq</tt> attribute is inlined into a
1063function that doesn't have an <tt>sspreq</tt> attribute or which has
1064an <tt>ssp</tt> attribute, then the resulting function will have
1065an <tt>sspreq</tt> attribute.</p></dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1066</dl>
1067
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1068</div>
1069
1070<!-- ======================================================================= -->
1071<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1072 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1073</div>
1074
1075<div class="doc_text">
1076<p>
1077Modules may contain "module-level inline asm" blocks, which corresponds to the
1078GCC "file scope inline asm" blocks. These blocks are internally concatenated by
1079LLVM and treated as a single unit, but may be separated in the .ll file if
1080desired. The syntax is very simple:
1081</p>
1082
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1083<div class="doc_code">
1084<pre>
1085module asm "inline asm code goes here"
1086module asm "more can go here"
1087</pre>
1088</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1089
1090<p>The strings can contain any character by escaping non-printable characters.
1091 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
1092 for the number.
1093</p>
1094
1095<p>
1096 The inline asm code is simply printed to the machine code .s file when
1097 assembly code is generated.
1098</p>
1099</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1100
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1101<!-- ======================================================================= -->
1102<div class="doc_subsection">
1103 <a name="datalayout">Data Layout</a>
1104</div>
1105
1106<div class="doc_text">
1107<p>A module may specify a target specific data layout string that specifies how
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]1108data is to be laid out in memory. The syntax for the data layout is simply:</p>
1109<pre> target datalayout = "<i>layout specification</i>"</pre>
1110<p>The <i>layout specification</i> consists of a list of specifications
1111separated by the minus sign character ('-'). Each specification starts with a
1112letter and may include other information after the letter to define some
1113aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1114<dl>
1115 <dt><tt>E</tt></dt>
1116 <dd>Specifies that the target lays out data in big-endian form. That is, the
1117 bits with the most significance have the lowest address location.</dd>
1118 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1119 <dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1120 the bits with the least significance have the lowest address location.</dd>
1121 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1122 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
1123 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
1124 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
1125 too.</dd>
1126 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1127 <dd>This specifies the alignment for an integer type of a given bit
1128 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1129 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1130 <dd>This specifies the alignment for a vector type of a given bit
1131 <i>size</i>.</dd>
1132 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1133 <dd>This specifies the alignment for a floating point type of a given bit
1134 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1135 (double).</dd>
1136 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1137 <dd>This specifies the alignment for an aggregate type of a given bit
1138 <i>size</i>.</dd>
1139</dl>
1140<p>When constructing the data layout for a given target, LLVM starts with a
1141default set of specifications which are then (possibly) overriden by the
1142specifications in the <tt>datalayout</tt> keyword. The default specifications
1143are given in this list:</p>
1144<ul>
1145 <li><tt>E</tt> - big endian</li>
1146 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1147 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1148 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1149 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1150 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1151 <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]1152 alignment of 64-bits</li>
1153 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1154 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1155 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1156 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1157 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
1158</ul>
Chris Lattnerebec6782008-08-05 18:21:08 +0000[diff] [blame]1159<p>When LLVM is determining the alignment for a given type, it uses the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1160following rules:</p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1161<ol>
1162 <li>If the type sought is an exact match for one of the specifications, that
1163 specification is used.</li>
1164 <li>If no match is found, and the type sought is an integer type, then the
1165 smallest integer type that is larger than the bitwidth of the sought type is
1166 used. If none of the specifications are larger than the bitwidth then the the
1167 largest integer type is used. For example, given the default specifications
1168 above, the i7 type will use the alignment of i8 (next largest) while both
1169 i65 and i256 will use the alignment of i64 (largest specified).</li>
1170 <li>If no match is found, and the type sought is a vector type, then the
1171 largest vector type that is smaller than the sought vector type will be used
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1172 as a fall back. This happens because &lt;128 x double&gt; can be implemented
1173 in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1174</ol>
1175</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1176
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1177<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1178<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1179<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1180
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1181<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1182
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1183<p>The LLVM type system is one of the most important features of the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1184intermediate representation. Being typed enables a number of
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1185optimizations to be performed on the intermediate representation directly,
1186without having to do
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1187extra analyses on the side before the transformation. A strong type
1188system makes it easier to read the generated code and enables novel
1189analyses and transformations that are not feasible to perform on normal
1190three address code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1191
1192</div>
1193
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1194<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1195<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1196Classifications</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1197<div class="doc_text">
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1198<p>The types fall into a few useful
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1199classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1200
1201<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1202 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1203 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1204 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1205 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1206 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1207 </tr>
1208 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1209 <td><a href="#t_floating">floating point</a></td>
1210 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1211 </tr>
1212 <tr>
1213 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1214 <td><a href="#t_integer">integer</a>,
1215 <a href="#t_floating">floating point</a>,
1216 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1217 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1218 <a href="#t_struct">structure</a>,
1219 <a href="#t_array">array</a>,
Dan Gohmanade5faa2008-05-23 22:50:26 +0000[diff] [blame]1220 <a href="#t_label">label</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1221 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1222 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1223 <tr>
1224 <td><a href="#t_primitive">primitive</a></td>
1225 <td><a href="#t_label">label</a>,
1226 <a href="#t_void">void</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1227 <a href="#t_floating">floating point</a>.</td>
1228 </tr>
1229 <tr>
1230 <td><a href="#t_derived">derived</a></td>
1231 <td><a href="#t_integer">integer</a>,
1232 <a href="#t_array">array</a>,
1233 <a href="#t_function">function</a>,
1234 <a href="#t_pointer">pointer</a>,
1235 <a href="#t_struct">structure</a>,
1236 <a href="#t_pstruct">packed structure</a>,
1237 <a href="#t_vector">vector</a>,
1238 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1239 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1240 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1241 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1242</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1243
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1244<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1245most important. Values of these types are the only ones which can be
1246produced by instructions, passed as arguments, or used as operands to
Dan Gohmanc4b49eb2008-05-23 21:53:15 +0000[diff] [blame]1247instructions.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1248</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1249
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1250<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1251<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1252
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1253<div class="doc_text">
1254<p>The primitive types are the fundamental building blocks of the LLVM
1255system.</p>
1256
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1257</div>
1258
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1259<!-- _______________________________________________________________________ -->
1260<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1261
1262<div class="doc_text">
1263 <table>
1264 <tbody>
1265 <tr><th>Type</th><th>Description</th></tr>
1266 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1267 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1268 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1269 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1270 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1271 </tbody>
1272 </table>
1273</div>
1274
1275<!-- _______________________________________________________________________ -->
1276<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1277
1278<div class="doc_text">
1279<h5>Overview:</h5>
1280<p>The void type does not represent any value and has no size.</p>
1281
1282<h5>Syntax:</h5>
1283
1284<pre>
1285 void
1286</pre>
1287</div>
1288
1289<!-- _______________________________________________________________________ -->
1290<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1291
1292<div class="doc_text">
1293<h5>Overview:</h5>
1294<p>The label type represents code labels.</p>
1295
1296<h5>Syntax:</h5>
1297
1298<pre>
1299 label
1300</pre>
1301</div>
1302
1303
1304<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1305<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1306
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1307<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1308
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1309<p>The real power in LLVM comes from the derived types in the system.
1310This is what allows a programmer to represent arrays, functions,
1311pointers, and other useful types. Note that these derived types may be
1312recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1313
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1314</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1315
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1316<!-- _______________________________________________________________________ -->
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1317<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1318
1319<div class="doc_text">
1320
1321<h5>Overview:</h5>
1322<p>The integer type is a very simple derived type that simply specifies an
1323arbitrary bit width for the integer type desired. Any bit width from 1 bit to
13242^23-1 (about 8 million) can be specified.</p>
1325
1326<h5>Syntax:</h5>
1327
1328<pre>
1329 iN
1330</pre>
1331
1332<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1333value.</p>
1334
1335<h5>Examples:</h5>
1336<table class="layout">
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]1337 <tbody>
1338 <tr>
1339 <td><tt>i1</tt></td>
1340 <td>a single-bit integer.</td>
1341 </tr><tr>
1342 <td><tt>i32</tt></td>
1343 <td>a 32-bit integer.</td>
1344 </tr><tr>
1345 <td><tt>i1942652</tt></td>
1346 <td>a really big integer of over 1 million bits.</td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1347 </tr>
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]1348 </tbody>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1349</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1350
1351<p>Note that the code generator does not yet support large integer types
1352to be used as function return types. The specific limit on how large a
1353return type the code generator can currently handle is target-dependent;
1354currently it's often 64 bits for 32-bit targets and 128 bits for 64-bit
1355targets.</p>
1356
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1357</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1358
1359<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1360<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1361
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1362<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1363
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1364<h5>Overview:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1365
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1366<p>The array type is a very simple derived type that arranges elements
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1367sequentially in memory. The array type requires a size (number of
1368elements) and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1369
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1370<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1371
1372<pre>
1373 [&lt;# elements&gt; x &lt;elementtype&gt;]
1374</pre>
1375
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1376<p>The number of elements is a constant integer value; elementtype may
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1377be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1378
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1379<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1380<table class="layout">
1381 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1382 <td class="left"><tt>[40 x i32]</tt></td>
1383 <td class="left">Array of 40 32-bit integer values.</td>
1384 </tr>
1385 <tr class="layout">
1386 <td class="left"><tt>[41 x i32]</tt></td>
1387 <td class="left">Array of 41 32-bit integer values.</td>
1388 </tr>
1389 <tr class="layout">
1390 <td class="left"><tt>[4 x i8]</tt></td>
1391 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1392 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1393</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1394<p>Here are some examples of multidimensional arrays:</p>
1395<table class="layout">
1396 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1397 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1398 <td class="left">3x4 array of 32-bit integer values.</td>
1399 </tr>
1400 <tr class="layout">
1401 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1402 <td class="left">12x10 array of single precision floating point values.</td>
1403 </tr>
1404 <tr class="layout">
1405 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1406 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1407 </tr>
1408</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1409
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1410<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1411length array. Normally, accesses past the end of an array are undefined in
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1412LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1413As a special case, however, zero length arrays are recognized to be variable
1414length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1415type "{ i32, [0 x float]}", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1416
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1417<p>Note that the code generator does not yet support large aggregate types
1418to be used as function return types. The specific limit on how large an
1419aggregate return type the code generator can currently handle is
1420target-dependent, and also dependent on the aggregate element types.</p>
1421
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1422</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1423
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1424<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1425<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1426<div class="doc_text">
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1427
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1428<h5>Overview:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1429
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1430<p>The function type can be thought of as a function signature. It
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1431consists of a return type and a list of formal parameter types. The
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1432return 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]1433If 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]1434class types, and the struct must have at least one element.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1435
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1436<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1437
1438<pre>
1439 &lt;returntype list&gt; (&lt;parameter list&gt;)
1440</pre>
1441
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1442<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]1443specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1444which indicates that the function takes a variable number of arguments.
1445Variable argument functions can access their arguments with the <a
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1446 href="#int_varargs">variable argument handling intrinsic</a> functions.
1447'<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1448<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1449
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1450<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1451<table class="layout">
1452 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1453 <td class="left"><tt>i32 (i32)</tt></td>
1454 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1455 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1456 </tr><tr class="layout">
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]1457 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1458 </tt></td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1459 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1460 an <tt>i16</tt> that should be sign extended and a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1461 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1462 <tt>float</tt>.
1463 </td>
1464 </tr><tr class="layout">
1465 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1466 <td class="left">A vararg function that takes at least one
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1467 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1468 which returns an integer. This is the signature for <tt>printf</tt> in
1469 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1470 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1471 </tr><tr class="layout">
1472 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukmanb0a57aa2008-11-27 06:41:20 +0000[diff] [blame]1473 <td class="left">A function taking an <tt>i32</tt>, returning two
1474 <tt>i32</tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1475 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1476 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1477</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1478
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1479</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1480<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1481<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1482<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1483<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1484<p>The structure type is used to represent a collection of data members
1485together in memory. The packing of the field types is defined to match
1486the ABI of the underlying processor. The elements of a structure may
1487be any type that has a size.</p>
1488<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1489and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1490field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1491instruction.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1492<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1493<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1494<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1495<table class="layout">
1496 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1497 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1498 <td class="left">A triple of three <tt>i32</tt> values</td>
1499 </tr><tr class="layout">
1500 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1501 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1502 second element is a <a href="#t_pointer">pointer</a> to a
1503 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1504 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1505 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1506</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1507
1508<p>Note that the code generator does not yet support large aggregate types
1509to be used as function return types. The specific limit on how large an
1510aggregate return type the code generator can currently handle is
1511target-dependent, and also dependent on the aggregate element types.</p>
1512
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1513</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1514
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1515<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1516<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1517</div>
1518<div class="doc_text">
1519<h5>Overview:</h5>
1520<p>The packed structure type is used to represent a collection of data members
1521together in memory. There is no padding between fields. Further, the alignment
1522of a packed structure is 1 byte. The elements of a packed structure may
1523be any type that has a size.</p>
1524<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1525and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1526field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1527instruction.</p>
1528<h5>Syntax:</h5>
1529<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1530<h5>Examples:</h5>
1531<table class="layout">
1532 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1533 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1534 <td class="left">A triple of three <tt>i32</tt> values</td>
1535 </tr><tr class="layout">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1536 <td class="left">
1537<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1538 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1539 second element is a <a href="#t_pointer">pointer</a> to a
1540 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1541 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1542 </tr>
1543</table>
1544</div>
1545
1546<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1547<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1548<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1549<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1550<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]1551reference to another object, which must live in memory. Pointer types may have
1552an optional address space attribute defining the target-specific numbered
1553address space where the pointed-to object resides. The default address space is
1554zero.</p>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1555<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1556<pre> &lt;type&gt; *<br></pre>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1557<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1558<table class="layout">
1559 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]1560 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1561 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1562 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1563 </tr>
1564 <tr class="layout">
1565 <td class="left"><tt>i32 (i32 *) *</tt></td>
1566 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1567 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1568 <tt>i32</tt>.</td>
1569 </tr>
1570 <tr class="layout">
1571 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1572 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1573 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1574 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1575</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1576</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1577
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1578<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1579<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1580<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1581
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1582<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1583
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1584<p>A vector type is a simple derived type that represents a vector
1585of elements. Vector types are used when multiple primitive data
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1586are operated in parallel using a single instruction (SIMD).
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1587A vector type requires a size (number of
Chris Lattnerb8d172f2005-11-10 01:44:22 +0000[diff] [blame]1588elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1589of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1590considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1591
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1592<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1593
1594<pre>
1595 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1596</pre>
1597
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1598<p>The number of elements is a constant integer value; elementtype may
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1599be any integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1600
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1601<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1602
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1603<table class="layout">
1604 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1605 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1606 <td class="left">Vector of 4 32-bit integer values.</td>
1607 </tr>
1608 <tr class="layout">
1609 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1610 <td class="left">Vector of 8 32-bit floating-point values.</td>
1611 </tr>
1612 <tr class="layout">
1613 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1614 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1615 </tr>
1616</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1617
1618<p>Note that the code generator does not yet support large vector types
1619to be used as function return types. The specific limit on how large a
1620vector return type codegen can currently handle is target-dependent;
1621currently it's often a few times longer than a hardware vector register.</p>
1622
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1623</div>
1624
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1625<!-- _______________________________________________________________________ -->
1626<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1627<div class="doc_text">
1628
1629<h5>Overview:</h5>
1630
1631<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksen8ac04ff2007-10-14 00:34:53 +0000[diff] [blame]1632corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1633In LLVM, opaque types can eventually be resolved to any type (not just a
1634structure type).</p>
1635
1636<h5>Syntax:</h5>
1637
1638<pre>
1639 opaque
1640</pre>
1641
1642<h5>Examples:</h5>
1643
1644<table class="layout">
1645 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1646 <td class="left"><tt>opaque</tt></td>
1647 <td class="left">An opaque type.</td>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1648 </tr>
1649</table>
1650</div>
1651
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1652<!-- ======================================================================= -->
1653<div class="doc_subsection">
1654 <a name="t_uprefs">Type Up-references</a>
1655</div>
1656
1657<div class="doc_text">
1658<h5>Overview:</h5>
1659<p>
1660An "up reference" allows you to refer to a lexically enclosing type without
1661requiring it to have a name. For instance, a structure declaration may contain a
1662pointer to any of the types it is lexically a member of. Example of up
1663references (with their equivalent as named type declarations) include:</p>
1664
1665<pre>
1666 { \2 * } %x = type { %t* }
1667 { \2 }* %y = type { %y }*
1668 \1* %z = type %z*
1669</pre>
1670
1671<p>
1672An up reference is needed by the asmprinter for printing out cyclic types when
1673there is no declared name for a type in the cycle. Because the asmprinter does
1674not want to print out an infinite type string, it needs a syntax to handle
1675recursive types that have no names (all names are optional in llvm IR).
1676</p>
1677
1678<h5>Syntax:</h5>
1679<pre>
1680 \&lt;level&gt;
1681</pre>
1682
1683<p>
1684The level is the count of the lexical type that is being referred to.
1685</p>
1686
1687<h5>Examples:</h5>
1688
1689<table class="layout">
1690 <tr class="layout">
1691 <td class="left"><tt>\1*</tt></td>
1692 <td class="left">Self-referential pointer.</td>
1693 </tr>
1694 <tr class="layout">
1695 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
1696 <td class="left">Recursive structure where the upref refers to the out-most
1697 structure.</td>
1698 </tr>
1699</table>
1700</div>
1701
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1702
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1703<!-- *********************************************************************** -->
1704<div class="doc_section"> <a name="constants">Constants</a> </div>
1705<!-- *********************************************************************** -->
1706
1707<div class="doc_text">
1708
1709<p>LLVM has several different basic types of constants. This section describes
1710them all and their syntax.</p>
1711
1712</div>
1713
1714<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1715<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1716
1717<div class="doc_text">
1718
1719<dl>
1720 <dt><b>Boolean constants</b></dt>
1721
1722 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1723 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1724 </dd>
1725
1726 <dt><b>Integer constants</b></dt>
1727
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1728 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1729 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1730 integer types.
1731 </dd>
1732
1733 <dt><b>Floating point constants</b></dt>
1734
1735 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1736 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]1737 notation (see below). The assembler requires the exact decimal value of
1738 a floating-point constant. For example, the assembler accepts 1.25 but
1739 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1740 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1741
1742 <dt><b>Null pointer constants</b></dt>
1743
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1744 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1745 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1746
1747</dl>
1748
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1749<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1750of floating point constants. For example, the form '<tt>double
17510x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
17524.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1753(and the only time that they are generated by the disassembler) is when a
1754floating point constant must be emitted but it cannot be represented as a
1755decimal floating point number. For example, NaN's, infinities, and other
1756special values are represented in their IEEE hexadecimal format so that
1757assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1758
1759</div>
1760
1761<!-- ======================================================================= -->
1762<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1763</div>
1764
1765<div class="doc_text">
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]1766<p>Aggregate constants arise from aggregation of simple constants
1767and smaller aggregate constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1768
1769<dl>
1770 <dt><b>Structure constants</b></dt>
1771
1772 <dd>Structure constants are represented with notation similar to structure
1773 type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner64910ee2007-12-25 20:34:52 +0000[diff] [blame]1774 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1775 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]1776 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1777 types of elements must match those specified by the type.
1778 </dd>
1779
1780 <dt><b>Array constants</b></dt>
1781
1782 <dd>Array constants are represented with notation similar to array type
1783 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1784 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1785 constants must have <a href="#t_array">array type</a>, and the number and
1786 types of elements must match those specified by the type.
1787 </dd>
1788
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1789 <dt><b>Vector constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1790
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1791 <dd>Vector constants are represented with notation similar to vector type
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1792 definitions (a comma separated list of elements, surrounded by
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1793 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]1794 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1795 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1796 match those specified by the type.
1797 </dd>
1798
1799 <dt><b>Zero initialization</b></dt>
1800
1801 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1802 value to zero of <em>any</em> type, including scalar and aggregate types.
1803 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]1804 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1805 initializers.
1806 </dd>
1807</dl>
1808
1809</div>
1810
1811<!-- ======================================================================= -->
1812<div class="doc_subsection">
1813 <a name="globalconstants">Global Variable and Function Addresses</a>
1814</div>
1815
1816<div class="doc_text">
1817
1818<p>The addresses of <a href="#globalvars">global variables</a> and <a
1819href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1820constants. These constants are explicitly referenced when the <a
1821href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1822href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1823file:</p>
1824
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1825<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1826<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]1827@X = global i32 17
1828@Y = global i32 42
1829@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1830</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1831</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1832
1833</div>
1834
1835<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1836<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1837<div class="doc_text">
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1838 <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]1839 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1840 a constant is permitted.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1841
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1842 <p>Undefined values indicate to the compiler that the program is well defined
1843 no matter what value is used, giving the compiler more freedom to optimize.
1844 </p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1845</div>
1846
1847<!-- ======================================================================= -->
1848<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1849</div>
1850
1851<div class="doc_text">
1852
1853<p>Constant expressions are used to allow expressions involving other constants
1854to be used as constants. Constant expressions may be of any <a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1855href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1856that does not have side effects (e.g. load and call are not supported). The
1857following is the syntax for constant expressions:</p>
1858
1859<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1860 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1861 <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]1862 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1863
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1864 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1865 <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]1866 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]1867
1868 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1869 <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]1870 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]1871
1872 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1873 <dd>Truncate a floating point constant to another floating point type. The
1874 size of CST must be larger than the size of TYPE. Both types must be
1875 floating point.</dd>
1876
1877 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1878 <dd>Floating point extend a constant to another type. The size of CST must be
1879 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1880
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]1881 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1882 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1883 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1884 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1885 of the same number of elements. If the value won't fit in the integer type,
1886 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1887
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1888 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1889 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1890 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1891 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1892 of the same number of elements. If the value won't fit in the integer type,
1893 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1894
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1895 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1896 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1897 constant. TYPE must be a scalar or vector floating point type. CST must be of
1898 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1899 of the same number of elements. If the value won't fit in the floating point
1900 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1901
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1902 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1903 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1904 constant. TYPE must be a scalar or vector floating point type. CST must be of
1905 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1906 of the same number of elements. If the value won't fit in the floating point
1907 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1908
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1909 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1910 <dd>Convert a pointer typed constant to the corresponding integer constant
1911 TYPE must be an integer type. CST must be of pointer type. The CST value is
1912 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1913
1914 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1915 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1916 pointer type. CST must be of integer type. The CST value is zero extended,
1917 truncated, or unchanged to make it fit in a pointer size. This one is
1918 <i>really</i> dangerous!</dd>
1919
1920 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1921 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1922 identical (same number of bits). The conversion is done as if the CST value
1923 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]1924 with this operator, just the type. This can be used for conversion of
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1925 vector types to any other type, as long as they have the same bit width. For
Dan Gohman500233a2008-09-08 16:45:59 +0000[diff] [blame]1926 pointers it is only valid to cast to another pointer type. It is not valid
1927 to bitcast to or from an aggregate type.
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1928 </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1929
1930 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1931
1932 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1933 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1934 instruction, the index list may have zero or more indexes, which are required
1935 to make sense for the type of "CSTPTR".</dd>
1936
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1937 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1938
1939 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1940 constants.</dd>
1941
1942 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1943 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1944
1945 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1946 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1947
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]1948 <dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
1949 <dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
1950
1951 <dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
1952 <dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
1953
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1954 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1955
1956 <dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1957 operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1958
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1959 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1960
1961 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1962 operation</a> on constants.</dd>
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1963
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1964
1965 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1966
1967 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1968 operation</a> on constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1969
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1970 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1971
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1972 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1973 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1974 binary</a> operations. The constraints on operands are the same as those for
1975 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1976 values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1977</dl>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1978</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]1979
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1980<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1981<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1982<!-- *********************************************************************** -->
1983
1984<!-- ======================================================================= -->
1985<div class="doc_subsection">
1986<a name="inlineasm">Inline Assembler Expressions</a>
1987</div>
1988
1989<div class="doc_text">
1990
1991<p>
1992LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1993Module-Level Inline Assembly</a>) through the use of a special value. This
1994value represents the inline assembler as a string (containing the instructions
1995to emit), a list of operand constraints (stored as a string), and a flag that
1996indicates whether or not the inline asm expression has side effects. An example
1997inline assembler expression is:
1998</p>
1999
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2000<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2001<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2002i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2003</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2004</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2005
2006<p>
2007Inline assembler expressions may <b>only</b> be used as the callee operand of
2008a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
2009</p>
2010
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2011<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2012<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2013%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]2014</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2015</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2016
2017<p>
2018Inline asms with side effects not visible in the constraint list must be marked
2019as having side effects. This is done through the use of the
2020'<tt>sideeffect</tt>' keyword, like so:
2021</p>
2022
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2023<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2024<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2025call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2026</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2027</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2028
2029<p>TODO: The format of the asm and constraints string still need to be
2030documented here. Constraints on what can be done (e.g. duplication, moving, etc
Chris Lattner4f993352008-10-04 18:36:02 +0000[diff] [blame]2031need to be documented). This is probably best done by reference to another
2032document that covers inline asm from a holistic perspective.
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2033</p>
2034
2035</div>
2036
2037<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2038<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
2039<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2040
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2041<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2042
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2043<p>The LLVM instruction set consists of several different
2044classifications of instructions: <a href="#terminators">terminator
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2045instructions</a>, <a href="#binaryops">binary instructions</a>,
2046<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2047 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
2048instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2049
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2050</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2051
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2052<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2053<div class="doc_subsection"> <a name="terminators">Terminator
2054Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2055
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2056<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2057
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2058<p>As mentioned <a href="#functionstructure">previously</a>, every
2059basic block in a program ends with a "Terminator" instruction, which
2060indicates which block should be executed after the current block is
2061finished. These terminator instructions typically yield a '<tt>void</tt>'
2062value: they produce control flow, not values (the one exception being
2063the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2064<p>There are six different terminator instructions: the '<a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2065 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
2066instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2067the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
2068 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
2069 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2070
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2071</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2072
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2073<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2074<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
2075Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2076<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2077<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2078<pre>
2079 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]2080 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2081</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2082
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2083<h5>Overview:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2084
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2085<p>The '<tt>ret</tt>' instruction is used to return control flow (and
2086optionally a value) from a function back to the caller.</p>
John Criswell4457dc92004-04-09 16:48:45 +0000[diff] [blame]2087<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2088returns a value and then causes control flow, and one that just causes
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2089control flow to occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2090
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2091<h5>Arguments:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2092
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2093<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
2094the return value. The type of the return value must be a
2095'<a href="#t_firstclass">first class</a>' type.</p>
2096
2097<p>A function is not <a href="#wellformed">well formed</a> if
2098it it has a non-void return type and contains a '<tt>ret</tt>'
2099instruction with no return value or a return value with a type that
2100does not match its type, or if it has a void return type and contains
2101a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2102
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2103<h5>Semantics:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2104
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2105<p>When the '<tt>ret</tt>' instruction is executed, control flow
2106returns back to the calling function's context. If the caller is a "<a
John Criswellfa081872004-06-25 15:16:57 +0000[diff] [blame]2107 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2108the instruction after the call. If the caller was an "<a
2109 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2110at the beginning of the "normal" destination block. If the instruction
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2111returns a value, that value shall set the call or invoke instruction's
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]2112return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2113
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2114<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2115
2116<pre>
2117 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2118 ret void <i>; Return from a void function</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2119 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]2120</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2121
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]2122<p>Note that the code generator does not yet fully support large
2123 return values. The specific sizes that are currently supported are
2124 dependent on the target. For integers, on 32-bit targets the limit
2125 is often 64 bits, and on 64-bit targets the limit is often 128 bits.
2126 For aggregate types, the current limits are dependent on the element
2127 types; for example targets are often limited to 2 total integer
2128 elements and 2 total floating-point elements.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2129
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2130</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2131<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2132<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2133<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2134<h5>Syntax:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2135<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]2136</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2137<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2138<p>The '<tt>br</tt>' instruction is used to cause control flow to
2139transfer to a different basic block in the current function. There are
2140two forms of this instruction, corresponding to a conditional branch
2141and an unconditional branch.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2142<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2143<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2144single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]2145unconditional form of the '<tt>br</tt>' instruction takes a single
2146'<tt>label</tt>' value as a target.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2147<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2148<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2149argument is evaluated. If the value is <tt>true</tt>, control flows
2150to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2151control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2152<h5>Example:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2153<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]2154 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]2155</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2156<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2157<div class="doc_subsubsection">
2158 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2159</div>
2160
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2161<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2162<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2163
2164<pre>
2165 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2166</pre>
2167
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2168<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2169
2170<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
2171several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2172instruction, allowing a branch to occur to one of many possible
2173destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2174
2175
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2176<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2177
2178<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
2179comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
2180an array of pairs of comparison value constants and '<tt>label</tt>'s. The
2181table is not allowed to contain duplicate constant entries.</p>
2182
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2183<h5>Semantics:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2184
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2185<p>The <tt>switch</tt> instruction specifies a table of values and
2186destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]2187table is searched for the given value. If the value is found, control flow is
2188transfered to the corresponding destination; otherwise, control flow is
2189transfered to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2190
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2191<h5>Implementation:</h5>
2192
2193<p>Depending on properties of the target machine and the particular
2194<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]2195ways. For example, it could be generated as a series of chained conditional
2196branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2197
2198<h5>Example:</h5>
2199
2200<pre>
2201 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2202 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2203 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2204
2205 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2206 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2207
2208 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2209 switch i32 %val, label %otherwise [ i32 0, label %onzero
2210 i32 1, label %onone
2211 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2212</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2213</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2214
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2215<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2216<div class="doc_subsubsection">
2217 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2218</div>
2219
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2220<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2221
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2222<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2223
2224<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2225 &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]2226 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2227</pre>
2228
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2229<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2230
2231<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
2232function, with the possibility of control flow transfer to either the
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2233'<tt>normal</tt>' label or the
2234'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2235"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
2236"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2237href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]2238continued at the dynamically nearest "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2239
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2240<h5>Arguments:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2241
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2242<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2243
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2244<ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2245 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]2246 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2247 convention</a> the call should use. If none is specified, the call defaults
2248 to using C calling conventions.
2249 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2250
2251 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
2252 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
2253 and '<tt>inreg</tt>' attributes are valid here.</li>
2254
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2255 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
2256 function value being invoked. In most cases, this is a direct function
2257 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
2258 an arbitrary pointer to function value.
2259 </li>
2260
2261 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
2262 function to be invoked. </li>
2263
2264 <li>'<tt>function args</tt>': argument list whose types match the function
2265 signature argument types. If the function signature indicates the function
2266 accepts a variable number of arguments, the extra arguments can be
2267 specified. </li>
2268
2269 <li>'<tt>normal label</tt>': the label reached when the called function
2270 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
2271
2272 <li>'<tt>exception label</tt>': the label reached when a callee returns with
2273 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
2274
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2275 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2276 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2277 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2278</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2279
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2280<h5>Semantics:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2281
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2282<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2283href="#i_call">call</a></tt>' instruction in most regards. The primary
2284difference is that it establishes an association with a label, which is used by
2285the runtime library to unwind the stack.</p>
2286
2287<p>This instruction is used in languages with destructors to ensure that proper
2288cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2289exception. Additionally, this is important for implementation of
2290'<tt>catch</tt>' clauses in high-level languages that support them.</p>
2291
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2292<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2293<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2294 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2295 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2296 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2297 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2298</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2299</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2300
2301
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2302<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2303
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2304<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2305Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2306
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2307<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2308
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2309<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2310<pre>
2311 unwind
2312</pre>
2313
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2314<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2315
2316<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
2317at the first callee in the dynamic call stack which used an <a
2318href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
2319primarily used to implement exception handling.</p>
2320
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2321<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2322
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]2323<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2324immediately halt. The dynamic call stack is then searched for the first <a
2325href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
2326execution continues at the "exceptional" destination block specified by the
2327<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
2328dynamic call chain, undefined behavior results.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2329</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2330
2331<!-- _______________________________________________________________________ -->
2332
2333<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2334Instruction</a> </div>
2335
2336<div class="doc_text">
2337
2338<h5>Syntax:</h5>
2339<pre>
2340 unreachable
2341</pre>
2342
2343<h5>Overview:</h5>
2344
2345<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
2346instruction is used to inform the optimizer that a particular portion of the
2347code is not reachable. This can be used to indicate that the code after a
2348no-return function cannot be reached, and other facts.</p>
2349
2350<h5>Semantics:</h5>
2351
2352<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
2353</div>
2354
2355
2356
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2357<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2358<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2359<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2360<p>Binary operators are used to do most of the computation in a
Chris Lattner5a158142008-04-01 18:47:32 +0000[diff] [blame]2361program. They require two operands of the same type, execute an operation on them, and
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2362produce a single value. The operands might represent
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2363multiple 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]2364The result value has the same type as its operands.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2365<p>There are several different binary operators:</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2366</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2367<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2368<div class="doc_subsubsection">
2369 <a name="i_add">'<tt>add</tt>' Instruction</a>
2370</div>
2371
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2372<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2373
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2374<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2375
2376<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2377 &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]2378</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2379
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2380<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2381
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2382<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2383
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2384<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2385
2386<p>The two arguments to the '<tt>add</tt>' instruction must be <a
2387 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
2388 <a href="#t_vector">vector</a> values. Both arguments must have identical
2389 types.</p>
2390
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2391<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2392
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2393<p>The value produced is the integer or floating point sum of the two
2394operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2395
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2396<p>If an integer sum has unsigned overflow, the result returned is the
2397mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2398the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2399
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2400<p>Because LLVM integers use a two's complement representation, this
2401instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2402
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2403<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2404
2405<pre>
2406 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2407</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2408</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2409<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2410<div class="doc_subsubsection">
2411 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2412</div>
2413
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2414<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2415
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2416<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2417
2418<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2419 &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]2420</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2421
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2422<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2423
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2424<p>The '<tt>sub</tt>' instruction returns the difference of its two
2425operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2426
2427<p>Note that the '<tt>sub</tt>' instruction is used to represent the
2428'<tt>neg</tt>' instruction present in most other intermediate
2429representations.</p>
2430
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2431<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2432
2433<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
2434 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2435 or <a href="#t_vector">vector</a> values. Both arguments must have identical
2436 types.</p>
2437
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2438<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2439
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2440<p>The value produced is the integer or floating point difference of
2441the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2442
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2443<p>If an integer difference has unsigned overflow, the result returned is the
2444mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2445the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2446
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2447<p>Because LLVM integers use a two's complement representation, this
2448instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2449
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2450<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2451<pre>
2452 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2453 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2454</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2455</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2456
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2457<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2458<div class="doc_subsubsection">
2459 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2460</div>
2461
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2462<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2463
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2464<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2465<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]2466</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2467<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2468<p>The '<tt>mul</tt>' instruction returns the product of its two
2469operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2470
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2471<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2472
2473<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
2474href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2475or <a href="#t_vector">vector</a> values. Both arguments must have identical
2476types.</p>
2477
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2478<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2479
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2480<p>The value produced is the integer or floating point product of the
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2481two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2482
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2483<p>If the result of an integer multiplication has unsigned overflow,
2484the result returned is the mathematical result modulo
24852<sup>n</sup>, where n is the bit width of the result.</p>
2486<p>Because LLVM integers use a two's complement representation, and the
2487result is the same width as the operands, this instruction returns the
2488correct result for both signed and unsigned integers. If a full product
2489(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
2490should be sign-extended or zero-extended as appropriate to the
2491width of the full product.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2492<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2493<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]2494</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2495</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2496
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2497<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2498<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2499</a></div>
2500<div class="doc_text">
2501<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2502<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]2503</pre>
2504<h5>Overview:</h5>
2505<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2506operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2507
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2508<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2509
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2510<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2511<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2512values. Both arguments must have identical types.</p>
2513
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2514<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2515
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2516<p>The value produced is the unsigned integer quotient of the two operands.</p>
2517<p>Note that unsigned integer division and signed integer division are distinct
2518operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2519<p>Division by zero leads to undefined behavior.</p>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2520<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2521<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]2522</pre>
2523</div>
2524<!-- _______________________________________________________________________ -->
2525<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2526</a> </div>
2527<div class="doc_text">
2528<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2529<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2530 &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]2531</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2532
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2533<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2534
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2535<p>The '<tt>sdiv</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
2540<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
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 Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2545<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]2546<p>Note that signed integer division and unsigned integer division are distinct
2547operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2548<p>Division by zero leads to undefined behavior. Overflow also leads to
2549undefined behavior; this is a rare case, but can occur, for example,
2550by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2551<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2552<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]2553</pre>
2554</div>
2555<!-- _______________________________________________________________________ -->
2556<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2557Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2558<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2559<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2560<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2561 &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]2562</pre>
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>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2566operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2567
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2568<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2569
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2570<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2571<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2572of floating point values. Both arguments must have identical types.</p>
2573
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2574<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2575
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2576<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2577
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2578<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2579
2580<pre>
2581 &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]2582</pre>
2583</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2584
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2585<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2586<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2587</div>
2588<div class="doc_text">
2589<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2590<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]2591</pre>
2592<h5>Overview:</h5>
2593<p>The '<tt>urem</tt>' instruction returns the remainder from the
2594unsigned division of its two arguments.</p>
2595<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2596<p>The two arguments to the '<tt>urem</tt>' instruction must be
2597<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2598values. Both arguments must have identical types.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2599<h5>Semantics:</h5>
2600<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2601This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2602<p>Note that unsigned integer remainder and signed integer remainder are
2603distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
2604<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2605<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2606<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]2607</pre>
2608
2609</div>
2610<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2611<div class="doc_subsubsection">
2612 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
2613</div>
2614
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2615<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2616
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2617<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2618
2619<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2620 &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]2621</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2622
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2623<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2624
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2625<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2626signed division of its two operands. This instruction can also take
2627<a href="#t_vector">vector</a> versions of the values in which case
2628the elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]2629
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2630<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2631
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2632<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2633<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2634values. Both arguments must have identical types.</p>
2635
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2636<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2637
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2638<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2639has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
2640operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2641a value. For more information about the difference, see <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2642 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2643Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencer64f5c6c2007-03-24 22:40:44 +0000[diff] [blame]2644please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2645Wikipedia: modulo operation</a>.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2646<p>Note that signed integer remainder and unsigned integer remainder are
2647distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
2648<p>Taking the remainder of a division by zero leads to undefined behavior.
2649Overflow also leads to undefined behavior; this is a rare case, but can occur,
2650for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
2651(The remainder doesn't actually overflow, but this rule lets srem be
2652implemented using instructions that return both the result of the division
2653and the remainder.)</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2654<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2655<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]2656</pre>
2657
2658</div>
2659<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2660<div class="doc_subsubsection">
2661 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
2662
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2663<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2664
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2665<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2666<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]2667</pre>
2668<h5>Overview:</h5>
2669<p>The '<tt>frem</tt>' instruction returns the remainder from the
2670division of its two operands.</p>
2671<h5>Arguments:</h5>
2672<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2673<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2674of floating point values. Both arguments must have identical types.</p>
2675
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2676<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2677
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2678<p>This instruction returns the <i>remainder</i> of a division.
2679The remainder has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2680
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2681<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2682
2683<pre>
2684 &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]2685</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2686</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]2687
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2688<!-- ======================================================================= -->
2689<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2690Operations</a> </div>
2691<div class="doc_text">
2692<p>Bitwise binary operators are used to do various forms of
2693bit-twiddling in a program. They are generally very efficient
2694instructions and can commonly be strength reduced from other
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2695instructions. They require two operands of the same type, execute an operation on them,
2696and 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]2697</div>
2698
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2699<!-- _______________________________________________________________________ -->
2700<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2701Instruction</a> </div>
2702<div class="doc_text">
2703<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2704<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]2705</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2706
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2707<h5>Overview:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2708
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2709<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2710the left a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2711
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2712<h5>Arguments:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2713
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2714<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2715 href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2716type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2717
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2718<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2719
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2720<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
2721where 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]2722equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
2723If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
2724corresponding shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2725
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2726<h5>Example:</h5><pre>
2727 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2728 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2729 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2730 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]2731 &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]2732</pre>
2733</div>
2734<!-- _______________________________________________________________________ -->
2735<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2736Instruction</a> </div>
2737<div class="doc_text">
2738<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2739<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]2740</pre>
2741
2742<h5>Overview:</h5>
2743<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2744operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2745
2746<h5>Arguments:</h5>
2747<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2748<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]2749type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2750
2751<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2752
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2753<p>This instruction always performs a logical shift right operation. The most
2754significant bits of the result will be filled with zero bits after the
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2755shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
Mon P Wang01f8d092008-12-10 08:55:09 +0000[diff] [blame]2756the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
2757vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
2758amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2759
2760<h5>Example:</h5>
2761<pre>
2762 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2763 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2764 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2765 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2766 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]2767 &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]2768</pre>
2769</div>
2770
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2771<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2772<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2773Instruction</a> </div>
2774<div class="doc_text">
2775
2776<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2777<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]2778</pre>
2779
2780<h5>Overview:</h5>
2781<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2782operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2783
2784<h5>Arguments:</h5>
2785<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2786<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2787type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2788
2789<h5>Semantics:</h5>
2790<p>This instruction always performs an arithmetic shift right operation,
2791The most significant bits of the result will be filled with the sign bit
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2792of <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]2793larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
2794arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
2795corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2796
2797<h5>Example:</h5>
2798<pre>
2799 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2800 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2801 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2802 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2803 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]2804 &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]2805</pre>
2806</div>
2807
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2808<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2809<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2810Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2811
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2812<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2813
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2814<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2815
2816<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2817 &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]2818</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2819
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2820<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2821
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2822<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2823its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2824
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2825<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2826
2827<p>The two arguments to the '<tt>and</tt>' instruction must be
2828<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2829values. Both arguments must have identical types.</p>
2830
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2831<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2832<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2833<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2834<div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2835<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2836 <tbody>
2837 <tr>
2838 <td>In0</td>
2839 <td>In1</td>
2840 <td>Out</td>
2841 </tr>
2842 <tr>
2843 <td>0</td>
2844 <td>0</td>
2845 <td>0</td>
2846 </tr>
2847 <tr>
2848 <td>0</td>
2849 <td>1</td>
2850 <td>0</td>
2851 </tr>
2852 <tr>
2853 <td>1</td>
2854 <td>0</td>
2855 <td>0</td>
2856 </tr>
2857 <tr>
2858 <td>1</td>
2859 <td>1</td>
2860 <td>1</td>
2861 </tr>
2862 </tbody>
2863</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2864</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2865<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2866<pre>
2867 &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]2868 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2869 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2870</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2871</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2872<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2873<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2874<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2875<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2876<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]2877</pre>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2878<h5>Overview:</h5>
2879<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2880or of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2881<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2882
2883<p>The two arguments to the '<tt>or</tt>' instruction must be
2884<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2885values. Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2886<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2887<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2888<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2889<div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2890<table border="1" cellspacing="0" cellpadding="4">
2891 <tbody>
2892 <tr>
2893 <td>In0</td>
2894 <td>In1</td>
2895 <td>Out</td>
2896 </tr>
2897 <tr>
2898 <td>0</td>
2899 <td>0</td>
2900 <td>0</td>
2901 </tr>
2902 <tr>
2903 <td>0</td>
2904 <td>1</td>
2905 <td>1</td>
2906 </tr>
2907 <tr>
2908 <td>1</td>
2909 <td>0</td>
2910 <td>1</td>
2911 </tr>
2912 <tr>
2913 <td>1</td>
2914 <td>1</td>
2915 <td>1</td>
2916 </tr>
2917 </tbody>
2918</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2919</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2920<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2921<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2922 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2923 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2924</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2925</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2926<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2927<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2928Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2929<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2930<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2931<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]2932</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2933<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2934<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2935or of its two operands. The <tt>xor</tt> is used to implement the
2936"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2937<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2938<p>The two arguments to the '<tt>xor</tt>' instruction must be
2939<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2940values. Both arguments must have identical types.</p>
2941
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2942<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2943
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2944<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2945<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2946<div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2947<table border="1" cellspacing="0" cellpadding="4">
2948 <tbody>
2949 <tr>
2950 <td>In0</td>
2951 <td>In1</td>
2952 <td>Out</td>
2953 </tr>
2954 <tr>
2955 <td>0</td>
2956 <td>0</td>
2957 <td>0</td>
2958 </tr>
2959 <tr>
2960 <td>0</td>
2961 <td>1</td>
2962 <td>1</td>
2963 </tr>
2964 <tr>
2965 <td>1</td>
2966 <td>0</td>
2967 <td>1</td>
2968 </tr>
2969 <tr>
2970 <td>1</td>
2971 <td>1</td>
2972 <td>0</td>
2973 </tr>
2974 </tbody>
2975</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2976</div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2977<p> </p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2978<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2979<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2980 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2981 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2982 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2983</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2984</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2985
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2986<!-- ======================================================================= -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2987<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2988 <a name="vectorops">Vector Operations</a>
2989</div>
2990
2991<div class="doc_text">
2992
2993<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2994target-independent manner. These instructions cover the element-access and
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2995vector-specific operations needed to process vectors effectively. While LLVM
2996does directly support these vector operations, many sophisticated algorithms
2997will want to use target-specific intrinsics to take full advantage of a specific
2998target.</p>
2999
3000</div>
3001
3002<!-- _______________________________________________________________________ -->
3003<div class="doc_subsubsection">
3004 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
3005</div>
3006
3007<div class="doc_text">
3008
3009<h5>Syntax:</h5>
3010
3011<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3012 &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]3013</pre>
3014
3015<h5>Overview:</h5>
3016
3017<p>
3018The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3019element from a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3020</p>
3021
3022
3023<h5>Arguments:</h5>
3024
3025<p>
3026The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3027value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3028an index indicating the position from which to extract the element.
3029The index may be a variable.</p>
3030
3031<h5>Semantics:</h5>
3032
3033<p>
3034The result is a scalar of the same type as the element type of
3035<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
3036<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3037results are undefined.
3038</p>
3039
3040<h5>Example:</h5>
3041
3042<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3043 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3044</pre>
3045</div>
3046
3047
3048<!-- _______________________________________________________________________ -->
3049<div class="doc_subsubsection">
3050 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
3051</div>
3052
3053<div class="doc_text">
3054
3055<h5>Syntax:</h5>
3056
3057<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]3058 &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]3059</pre>
3060
3061<h5>Overview:</h5>
3062
3063<p>
3064The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3065element into a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3066</p>
3067
3068
3069<h5>Arguments:</h5>
3070
3071<p>
3072The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3073value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3074scalar value whose type must equal the element type of the first
3075operand. The third operand is an index indicating the position at
3076which to insert the value. The index may be a variable.</p>
3077
3078<h5>Semantics:</h5>
3079
3080<p>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3081The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3082element values are those of <tt>val</tt> except at position
3083<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
3084exceeds the length of <tt>val</tt>, the results are undefined.
3085</p>
3086
3087<h5>Example:</h5>
3088
3089<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3090 %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]3091</pre>
3092</div>
3093
3094<!-- _______________________________________________________________________ -->
3095<div class="doc_subsubsection">
3096 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3097</div>
3098
3099<div class="doc_text">
3100
3101<h5>Syntax:</h5>
3102
3103<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3104 &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]3105</pre>
3106
3107<h5>Overview:</h5>
3108
3109<p>
3110The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3111from two input vectors, returning a vector with the same element type as
3112the input and length that is the same as the shuffle mask.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3113</p>
3114
3115<h5>Arguments:</h5>
3116
3117<p>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3118The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
3119with types that match each other. The third argument is a shuffle mask whose
3120element type is always 'i32'. The result of the instruction is a vector whose
3121length is the same as the shuffle mask and whose element type is the same as
3122the element type of the first two operands.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3123</p>
3124
3125<p>
3126The shuffle mask operand is required to be a constant vector with either
3127constant integer or undef values.
3128</p>
3129
3130<h5>Semantics:</h5>
3131
3132<p>
3133The elements of the two input vectors are numbered from left to right across
3134both of the vectors. The shuffle mask operand specifies, for each element of
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3135the result vector, which element of the two input vectors the result element
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3136gets. The element selector may be undef (meaning "don't care") and the second
3137operand may be undef if performing a shuffle from only one vector.
3138</p>
3139
3140<h5>Example:</h5>
3141
3142<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3143 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3144 &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]3145 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
3146 &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]3147 %result = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
3148 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
3149 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
3150 &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]3151</pre>
3152</div>
3153
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]3154
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3155<!-- ======================================================================= -->
3156<div class="doc_subsection">
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3157 <a name="aggregateops">Aggregate Operations</a>
3158</div>
3159
3160<div class="doc_text">
3161
3162<p>LLVM supports several instructions for working with aggregate values.
3163</p>
3164
3165</div>
3166
3167<!-- _______________________________________________________________________ -->
3168<div class="doc_subsubsection">
3169 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3170</div>
3171
3172<div class="doc_text">
3173
3174<h5>Syntax:</h5>
3175
3176<pre>
3177 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3178</pre>
3179
3180<h5>Overview:</h5>
3181
3182<p>
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3183The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3184or array element from an aggregate value.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3185</p>
3186
3187
3188<h5>Arguments:</h5>
3189
3190<p>
3191The first operand of an '<tt>extractvalue</tt>' instruction is a
3192value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3193type. The operands are constant indices to specify which value to extract
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3194in a similar manner as indices in a
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3195'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3196</p>
3197
3198<h5>Semantics:</h5>
3199
3200<p>
3201The result is the value at the position in the aggregate specified by
3202the index operands.
3203</p>
3204
3205<h5>Example:</h5>
3206
3207<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3208 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3209</pre>
3210</div>
3211
3212
3213<!-- _______________________________________________________________________ -->
3214<div class="doc_subsubsection">
3215 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3216</div>
3217
3218<div class="doc_text">
3219
3220<h5>Syntax:</h5>
3221
3222<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3223 &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]3224</pre>
3225
3226<h5>Overview:</h5>
3227
3228<p>
3229The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3230into a struct field or array element in an aggregate.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3231</p>
3232
3233
3234<h5>Arguments:</h5>
3235
3236<p>
3237The first operand of an '<tt>insertvalue</tt>' instruction is a
3238value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
3239The second operand is a first-class value to insert.
Dan Gohmanc4b49eb2008-05-23 21:53:15 +0000[diff] [blame]3240The following operands are constant indices
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3241indicating the position at which to insert the value in a similar manner as
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3242indices in a
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3243'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3244The value to insert must have the same type as the value identified
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3245by the indices.
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3246</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3247
3248<h5>Semantics:</h5>
3249
3250<p>
3251The result is an aggregate of the same type as <tt>val</tt>. Its
3252value is that of <tt>val</tt> except that the value at the position
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3253specified by the indices is that of <tt>elt</tt>.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3254</p>
3255
3256<h5>Example:</h5>
3257
3258<pre>
Dan Gohman52bb2db2008-06-23 15:26:37 +0000[diff] [blame]3259 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3260</pre>
3261</div>
3262
3263
3264<!-- ======================================================================= -->
3265<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3266 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3267</div>
3268
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3269<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3270
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3271<p>A key design point of an SSA-based representation is how it
3272represents memory. In LLVM, no memory locations are in SSA form, which
3273makes things very simple. This section describes how to read, write,
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3274allocate, and free memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3275
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3276</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3277
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3278<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3279<div class="doc_subsubsection">
3280 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3281</div>
3282
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3283<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3284
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3285<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3286
3287<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3288 &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]3289</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3290
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3291<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3292
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3293<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]3294heap and returns a pointer to it. The object is always allocated in the generic
3295address space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3296
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3297<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3298
3299<p>The '<tt>malloc</tt>' instruction allocates
3300<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswell6e4ca612004-02-24 16:13:56 +0000[diff] [blame]3301bytes of memory from the operating system and returns a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3302appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3303number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3304If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3305be aligned to at least that boundary. If not specified, or if zero, the target can
3306choose to align the allocation on any convenient boundary.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3307
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3308<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3309
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3310<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3311
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3312<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewycky02ff3082008-11-24 03:41:24 +0000[diff] [blame]3313a pointer is returned. The result of a zero byte allocation is undefined. The
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3314result is null if there is insufficient memory available.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3315
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3316<h5>Example:</h5>
3317
3318<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3319 %array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3320
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3321 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3322 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3323 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3324 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3325 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3326</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]3327
3328<p>Note that the code generator does not yet respect the
3329 alignment value.</p>
3330
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3331</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3332
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3333<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3334<div class="doc_subsubsection">
3335 <a name="i_free">'<tt>free</tt>' Instruction</a>
3336</div>
3337
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3338<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3339
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3340<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3341
3342<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3343 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3344</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3345
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3346<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3347
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3348<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]3349memory heap to be reallocated in the future.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3350
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3351<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3352
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3353<p>'<tt>value</tt>' shall be a pointer value that points to a value
3354that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
3355instruction.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3356
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3357<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3358
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3359<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattnere0db56d2008-04-19 22:41:32 +0000[diff] [blame]3360after this instruction executes. If the pointer is null, the operation
3361is a noop.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3362
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3363<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3364
3365<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3366 %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]3367 free [4 x i8]* %array
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3368</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3369</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3370
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3371<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3372<div class="doc_subsubsection">
3373 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3374</div>
3375
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3376<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3377
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3378<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3379
3380<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3381 &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]3382</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3383
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3384<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3385
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3386<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
3387currently executing function, to be automatically released when this function
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]3388returns to its caller. The object is always allocated in the generic address
3389space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3390
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3391<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3392
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3393<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3394bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3395appropriate type to the program. If "NumElements" is specified, it is the
3396number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3397If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3398to be aligned to at least that boundary. If not specified, or if zero, the target
3399can choose to align the allocation on any convenient boundary.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3400
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3401<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3402
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3403<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3404
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3405<p>Memory is allocated; a pointer is returned. The operation is undefiend if
3406there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3407memory is automatically released when the function returns. The '<tt>alloca</tt>'
3408instruction is commonly used to represent automatic variables that must
3409have an address available. When the function returns (either with the <tt><a
John Criswelldae2e932005-05-12 16:55:34 +0000[diff] [blame]3410 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]3411instructions), the memory is reclaimed. Allocating zero bytes
3412is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3413
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3414<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3415
3416<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3417 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
3418 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3419 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
3420 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3421</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3422</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3423
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3424<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3425<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3426Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3427<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3428<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]3429<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]3430<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3431<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3432<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3433<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]3434address from which to load. The pointer must point to a <a
Chris Lattnere53e5082004-06-03 22:57:15 +0000[diff] [blame]3435 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]3436marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3437the number or order of execution of this <tt>load</tt> with other
3438volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3439instructions. </p>
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3440<p>
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3441The optional constant "align" argument specifies the alignment of the operation
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3442(that is, the alignment of the memory address). A value of 0 or an
3443omitted "align" argument means that the operation has the preferential
3444alignment for the target. It is the responsibility of the code emitter
3445to ensure that the alignment information is correct. Overestimating
3446the alignment results in an undefined behavior. Underestimating the
3447alignment may produce less efficient code. An alignment of 1 is always
3448safe.
3449</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3450<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3451<p>The location of memory pointed to is loaded.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3452<h5>Examples:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3453<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3454 <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3455 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
3456 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3457</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3458</div>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3459<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3460<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3461Instruction</a> </div>
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]3462<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3463<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]3464<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
3465 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]3466</pre>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3467<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3468<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3469<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3470<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3471to 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]3472operand must be a pointer to the <a href="#t_firstclass">first class</a> type
3473of the '<tt>&lt;value&gt;</tt>'
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]3474operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3475optimizer is not allowed to modify the number or order of execution of
3476this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
3477 href="#i_store">store</a></tt> instructions.</p>
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3478<p>
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3479The optional constant "align" argument specifies the alignment of the operation
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3480(that is, the alignment of the memory address). A value of 0 or an
3481omitted "align" argument means that the operation has the preferential
3482alignment for the target. It is the responsibility of the code emitter
3483to ensure that the alignment information is correct. Overestimating
3484the alignment results in an undefined behavior. Underestimating the
3485alignment may produce less efficient code. An alignment of 1 is always
3486safe.
3487</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3488<h5>Semantics:</h5>
3489<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
3490at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3491<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3492<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]3493 store i32 3, i32* %ptr <i>; yields {void}</i>
3494 %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]3495</pre>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3496</div>
3497
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3498<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3499<div class="doc_subsubsection">
3500 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3501</div>
3502
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3503<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3504<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3505<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3506 &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]3507</pre>
3508
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3509<h5>Overview:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3510
3511<p>
3512The '<tt>getelementptr</tt>' instruction is used to get the address of a
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3513subelement of an aggregate data structure. It performs address calculation only
3514and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3515
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3516<h5>Arguments:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3517
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3518<p>The first argument is always a pointer, and forms the basis of the
3519calculation. The remaining arguments are indices, that indicate which of the
3520elements of the aggregate object are indexed. The interpretation of each index
3521is dependent on the type being indexed into. The first index always indexes the
3522pointer value given as the first argument, the second index indexes a value of
3523the type pointed to (not necessarily the value directly pointed to, since the
3524first index can be non-zero), etc. The first type indexed into must be a pointer
3525value, subsequent types can be arrays, vectors and structs. Note that subsequent
3526types being indexed into can never be pointers, since that would require loading
3527the pointer before continuing calculation.</p>
3528
3529<p>The type of each index argument depends on the type it is indexing into.
3530When indexing into a (packed) structure, only <tt>i32</tt> integer
3531<b>constants</b> are allowed. When indexing into an array, pointer or vector,
3532only integers of 32 or 64 bits are allowed (also non-constants). 32-bit values
3533will be sign extended to 64-bits if required.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3534
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3535<p>For example, let's consider a C code fragment and how it gets
3536compiled to LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3537
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3538<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3539<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3540struct RT {
3541 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3542 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3543 char C;
3544};
3545struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3546 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3547 double Y;
3548 struct RT Z;
3549};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3550
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3551int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3552 return &amp;s[1].Z.B[5][13];
3553}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3554</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3555</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3556
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3557<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3558
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3559<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3560<pre>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]3561%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
3562%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3563
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3564define i32* %foo(%ST* %s) {
3565entry:
3566 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3567 ret i32* %reg
3568}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3569</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3570</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3571
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3572<h5>Semantics:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3573
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3574<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]3575type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3576}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3577the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3578i8 }</tt>' type, another structure. The third index indexes into the second
3579element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3580array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3581'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
3582to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3583
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3584<p>Note that it is perfectly legal to index partially through a
3585structure, returning a pointer to an inner element. Because of this,
3586the LLVM code for the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3587
3588<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3589 define i32* %foo(%ST* %s) {
3590 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3591 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3592 %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]3593 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3594 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
3595 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3596 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3597</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3598
3599<p>Note that it is undefined to access an array out of bounds: array and
3600pointer indexes must always be within the defined bounds of the array type.
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]3601The one exception for this rule is zero length arrays. These arrays are
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3602defined to be accessible as variable length arrays, which requires access
3603beyond the zero'th element.</p>
3604
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3605<p>The getelementptr instruction is often confusing. For some more insight
3606into how it works, see <a href="GetElementPtr.html">the getelementptr
3607FAQ</a>.</p>
3608
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3609<h5>Example:</h5>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3610
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3611<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3612 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3613 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
3614 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3615 %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]3616 <i>; yields i8*:eptr</i>
3617 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3618</pre>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3619</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3620
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3621<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3622<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3623</div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3624<div class="doc_text">
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3625<p>The instructions in this category are the conversion instructions (casting)
3626which all take a single operand and a type. They perform various bit conversions
3627on the operand.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3628</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3629
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3630<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3631<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3632 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
3633</div>
3634<div class="doc_text">
3635
3636<h5>Syntax:</h5>
3637<pre>
3638 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3639</pre>
3640
3641<h5>Overview:</h5>
3642<p>
3643The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
3644</p>
3645
3646<h5>Arguments:</h5>
3647<p>
3648The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
3649be 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]3650and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3651type. The bit size of <tt>value</tt> must be larger than the bit size of
3652<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3653
3654<h5>Semantics:</h5>
3655<p>
3656The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3657and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
3658larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
3659It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3660
3661<h5>Example:</h5>
3662<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3663 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3664 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
3665 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3666</pre>
3667</div>
3668
3669<!-- _______________________________________________________________________ -->
3670<div class="doc_subsubsection">
3671 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
3672</div>
3673<div class="doc_text">
3674
3675<h5>Syntax:</h5>
3676<pre>
3677 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3678</pre>
3679
3680<h5>Overview:</h5>
3681<p>The '<tt>zext</tt>' instruction zero extends its operand to type
3682<tt>ty2</tt>.</p>
3683
3684
3685<h5>Arguments:</h5>
3686<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]3687<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3688also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3689<tt>value</tt> must be smaller than the bit size of the destination type,
3690<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3691
3692<h5>Semantics:</h5>
3693<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]3694bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3695
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]3696<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]3697
3698<h5>Example:</h5>
3699<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3700 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3701 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3702</pre>
3703</div>
3704
3705<!-- _______________________________________________________________________ -->
3706<div class="doc_subsubsection">
3707 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3708</div>
3709<div class="doc_text">
3710
3711<h5>Syntax:</h5>
3712<pre>
3713 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3714</pre>
3715
3716<h5>Overview:</h5>
3717<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3718
3719<h5>Arguments:</h5>
3720<p>
3721The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3722<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3723also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3724<tt>value</tt> must be smaller than the bit size of the destination type,
3725<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3726
3727<h5>Semantics:</h5>
3728<p>
3729The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3730bit (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]3731the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3732
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3733<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]3734
3735<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3736<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3737 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3738 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3739</pre>
3740</div>
3741
3742<!-- _______________________________________________________________________ -->
3743<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3744 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3745</div>
3746
3747<div class="doc_text">
3748
3749<h5>Syntax:</h5>
3750
3751<pre>
3752 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3753</pre>
3754
3755<h5>Overview:</h5>
3756<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3757<tt>ty2</tt>.</p>
3758
3759
3760<h5>Arguments:</h5>
3761<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3762 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3763cast it to. The size of <tt>value</tt> must be larger than the size of
3764<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3765<i>no-op cast</i>.</p>
3766
3767<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3768<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3769<a href="#t_floating">floating point</a> type to a smaller
3770<a href="#t_floating">floating point</a> type. If the value cannot fit within
3771the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3772
3773<h5>Example:</h5>
3774<pre>
3775 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3776 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3777</pre>
3778</div>
3779
3780<!-- _______________________________________________________________________ -->
3781<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3782 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3783</div>
3784<div class="doc_text">
3785
3786<h5>Syntax:</h5>
3787<pre>
3788 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3789</pre>
3790
3791<h5>Overview:</h5>
3792<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3793floating point value.</p>
3794
3795<h5>Arguments:</h5>
3796<p>The '<tt>fpext</tt>' instruction takes a
3797<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3798and a <a href="#t_floating">floating point</a> type to cast it to. The source
3799type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3800
3801<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3802<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3803<a href="#t_floating">floating point</a> type to a larger
3804<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3805used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3806<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]3807
3808<h5>Example:</h5>
3809<pre>
3810 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3811 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3812</pre>
3813</div>
3814
3815<!-- _______________________________________________________________________ -->
3816<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]3817 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3818</div>
3819<div class="doc_text">
3820
3821<h5>Syntax:</h5>
3822<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3823 &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]3824</pre>
3825
3826<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3827<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3828unsigned integer equivalent of type <tt>ty2</tt>.
3829</p>
3830
3831<h5>Arguments:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3832<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]3833scalar or vector <a href="#t_floating">floating point</a> value, and a type
3834to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3835type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3836vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3837
3838<h5>Semantics:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3839<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3840<a href="#t_floating">floating point</a> operand into the nearest (rounding
3841towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3842the results are undefined.</p>
3843
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3844<h5>Example:</h5>
3845<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3846 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3847 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3848 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3849</pre>
3850</div>
3851
3852<!-- _______________________________________________________________________ -->
3853<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3854 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3855</div>
3856<div class="doc_text">
3857
3858<h5>Syntax:</h5>
3859<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3860 &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]3861</pre>
3862
3863<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3864<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3865<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]3866</p>
3867
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3868<h5>Arguments:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3869<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]3870scalar or vector <a href="#t_floating">floating point</a> value, and a type
3871to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3872type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3873vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3874
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3875<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3876<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3877<a href="#t_floating">floating point</a> operand into the nearest (rounding
3878towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3879the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3880
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3881<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3882<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3883 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3884 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3885 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3886</pre>
3887</div>
3888
3889<!-- _______________________________________________________________________ -->
3890<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3891 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3892</div>
3893<div class="doc_text">
3894
3895<h5>Syntax:</h5>
3896<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3897 &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]3898</pre>
3899
3900<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3901<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3902integer and converts that value to the <tt>ty2</tt> type.</p>
3903
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3904<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3905<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3906scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3907to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3908type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3909floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3910
3911<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3912<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3913integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3914the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3915
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3916<h5>Example:</h5>
3917<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3918 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3919 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3920</pre>
3921</div>
3922
3923<!-- _______________________________________________________________________ -->
3924<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3925 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3926</div>
3927<div class="doc_text">
3928
3929<h5>Syntax:</h5>
3930<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3931 &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]3932</pre>
3933
3934<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3935<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3936integer and converts that value to the <tt>ty2</tt> type.</p>
3937
3938<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3939<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3940scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3941to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3942type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3943floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3944
3945<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3946<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3947integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3948the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3949
3950<h5>Example:</h5>
3951<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3952 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3953 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3954</pre>
3955</div>
3956
3957<!-- _______________________________________________________________________ -->
3958<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3959 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3960</div>
3961<div class="doc_text">
3962
3963<h5>Syntax:</h5>
3964<pre>
3965 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3966</pre>
3967
3968<h5>Overview:</h5>
3969<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3970the integer type <tt>ty2</tt>.</p>
3971
3972<h5>Arguments:</h5>
3973<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3974must 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]3975<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]3976
3977<h5>Semantics:</h5>
3978<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3979<tt>ty2</tt> by interpreting the pointer value as an integer and either
3980truncating or zero extending that value to the size of the integer type. If
3981<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3982<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]3983are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3984change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3985
3986<h5>Example:</h5>
3987<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3988 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3989 %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]3990</pre>
3991</div>
3992
3993<!-- _______________________________________________________________________ -->
3994<div class="doc_subsubsection">
3995 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3996</div>
3997<div class="doc_text">
3998
3999<h5>Syntax:</h5>
4000<pre>
4001 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4002</pre>
4003
4004<h5>Overview:</h5>
4005<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
4006a pointer type, <tt>ty2</tt>.</p>
4007
4008<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4009<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4010value to cast, and a type to cast it to, which must be a
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4011<a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4012
4013<h5>Semantics:</h5>
4014<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
4015<tt>ty2</tt> by applying either a zero extension or a truncation depending on
4016the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
4017size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
4018the size of a pointer then a zero extension is done. If they are the same size,
4019nothing is done (<i>no-op cast</i>).</p>
4020
4021<h5>Example:</h5>
4022<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4023 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
4024 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
4025 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4026</pre>
4027</div>
4028
4029<!-- _______________________________________________________________________ -->
4030<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4031 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4032</div>
4033<div class="doc_text">
4034
4035<h5>Syntax:</h5>
4036<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4037 &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]4038</pre>
4039
4040<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4041
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4042<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4043<tt>ty2</tt> without changing any bits.</p>
4044
4045<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4046
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4047<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Dan Gohman500233a2008-09-08 16:45:59 +0000[diff] [blame]4048a non-aggregate first class value, and a type to cast it to, which must also be
4049a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
4050<tt>value</tt>
Reid Spencer19b569f2007-01-09 20:08:58 +0000[diff] [blame]4051and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4052type is a pointer, the destination type must also be a pointer. This
4053instruction supports bitwise conversion of vectors to integers and to vectors
4054of other types (as long as they have the same size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4055
4056<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4057<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4058<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
4059this conversion. The conversion is done as if the <tt>value</tt> had been
4060stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
4061converted to other pointer types with this instruction. To convert pointers to
4062other types, use the <a href="#i_inttoptr">inttoptr</a> or
4063<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4064
4065<h5>Example:</h5>
4066<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4067 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4068 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4069 %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]4070</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4071</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4072
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4073<!-- ======================================================================= -->
4074<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
4075<div class="doc_text">
4076<p>The instructions in this category are the "miscellaneous"
4077instructions, which defy better classification.</p>
4078</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4079
4080<!-- _______________________________________________________________________ -->
4081<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4082</div>
4083<div class="doc_text">
4084<h5>Syntax:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4085<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]4086</pre>
4087<h5>Overview:</h5>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4088<p>The '<tt>icmp</tt>' instruction returns a boolean value or
4089a vector of boolean values based on comparison
4090of its two integer, integer vector, or pointer operands.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4091<h5>Arguments:</h5>
4092<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4093the condition code indicating the kind of comparison to perform. It is not
4094a value, just a keyword. The possible condition code are:
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4095</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4096<ol>
4097 <li><tt>eq</tt>: equal</li>
4098 <li><tt>ne</tt>: not equal </li>
4099 <li><tt>ugt</tt>: unsigned greater than</li>
4100 <li><tt>uge</tt>: unsigned greater or equal</li>
4101 <li><tt>ult</tt>: unsigned less than</li>
4102 <li><tt>ule</tt>: unsigned less or equal</li>
4103 <li><tt>sgt</tt>: signed greater than</li>
4104 <li><tt>sge</tt>: signed greater or equal</li>
4105 <li><tt>slt</tt>: signed less than</li>
4106 <li><tt>sle</tt>: signed less or equal</li>
4107</ol>
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]4108<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4109<a href="#t_pointer">pointer</a>
4110or integer <a href="#t_vector">vector</a> typed.
4111They must also be identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4112<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4113<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]4114the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4115yields 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]4116</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4117<ol>
4118 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
4119 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
4120 </li>
4121 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4122 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4123 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4124 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4125 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4126 <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]4127 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4128 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4129 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4130 <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]4131 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4132 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4133 <li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4134 <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]4135 <li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4136 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4137 <li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4138 <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]4139</ol>
4140<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4141values are compared as if they were integers.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4142<p>If the operands are integer vectors, then they are compared
4143element by element. The result is an <tt>i1</tt> vector with
4144the same number of elements as the values being compared.
4145Otherwise, the result is an <tt>i1</tt>.
4146</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4147
4148<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4149<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
4150 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4151 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4152 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4153 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4154 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4155</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4156
4157<p>Note that the code generator does not yet support vector types with
4158 the <tt>icmp</tt> instruction.</p>
4159
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4160</div>
4161
4162<!-- _______________________________________________________________________ -->
4163<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4164</div>
4165<div class="doc_text">
4166<h5>Syntax:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4167<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]4168</pre>
4169<h5>Overview:</h5>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4170<p>The '<tt>fcmp</tt>' instruction returns a boolean value
4171or vector of boolean values based on comparison
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4172of its operands.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4173<p>
4174If the operands are floating point scalars, then the result
4175type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
4176</p>
4177<p>If the operands are floating point vectors, then the result type
4178is a vector of boolean with the same number of elements as the
4179operands being compared.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4180<h5>Arguments:</h5>
4181<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4182the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4183a value, just a keyword. The possible condition code are:</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4184<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4185 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4186 <li><tt>oeq</tt>: ordered and equal</li>
4187 <li><tt>ogt</tt>: ordered and greater than </li>
4188 <li><tt>oge</tt>: ordered and greater than or equal</li>
4189 <li><tt>olt</tt>: ordered and less than </li>
4190 <li><tt>ole</tt>: ordered and less than or equal</li>
4191 <li><tt>one</tt>: ordered and not equal</li>
4192 <li><tt>ord</tt>: ordered (no nans)</li>
4193 <li><tt>ueq</tt>: unordered or equal</li>
4194 <li><tt>ugt</tt>: unordered or greater than </li>
4195 <li><tt>uge</tt>: unordered or greater than or equal</li>
4196 <li><tt>ult</tt>: unordered or less than </li>
4197 <li><tt>ule</tt>: unordered or less than or equal</li>
4198 <li><tt>une</tt>: unordered or not equal</li>
4199 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4200 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4201</ol>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4202<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer93a49852006-12-06 07:08:07 +0000[diff] [blame]4203<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4204<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
4205either a <a href="#t_floating">floating point</a> type
4206or a <a href="#t_vector">vector</a> of floating point type.
4207They must have identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4208<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4209<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4210according to the condition code given as <tt>cond</tt>.
4211If the operands are vectors, then the vectors are compared
4212element by element.
4213Each comparison performed
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4214always yields an <a href="#t_primitive">i1</a> result, as follows:</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4215<ol>
4216 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4217 <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]4218 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4219 <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]4220 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4221 <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]4222 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4223 <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]4224 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4225 <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]4226 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4227 <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]4228 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4229 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
4230 <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]4231 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4232 <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]4233 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4234 <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]4235 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4236 <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]4237 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4238 <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]4239 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4240 <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]4241 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4242 <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]4243 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4244</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4245
4246<h5>Example:</h5>
4247<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]4248 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4249 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4250 &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]4251</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4252
4253<p>Note that the code generator does not yet support vector types with
4254 the <tt>fcmp</tt> instruction.</p>
4255
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4256</div>
4257
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4258<!-- _______________________________________________________________________ -->
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4259<div class="doc_subsubsection">
4260 <a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
4261</div>
4262<div class="doc_text">
4263<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4264<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]4265</pre>
4266<h5>Overview:</h5>
4267<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
4268element-wise comparison of its two integer vector operands.</p>
4269<h5>Arguments:</h5>
4270<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
4271the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4272a value, just a keyword. The possible condition code are:</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4273<ol>
4274 <li><tt>eq</tt>: equal</li>
4275 <li><tt>ne</tt>: not equal </li>
4276 <li><tt>ugt</tt>: unsigned greater than</li>
4277 <li><tt>uge</tt>: unsigned greater or equal</li>
4278 <li><tt>ult</tt>: unsigned less than</li>
4279 <li><tt>ule</tt>: unsigned less or equal</li>
4280 <li><tt>sgt</tt>: signed greater than</li>
4281 <li><tt>sge</tt>: signed greater or equal</li>
4282 <li><tt>slt</tt>: signed less than</li>
4283 <li><tt>sle</tt>: signed less or equal</li>
4284</ol>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4285<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4286<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
4287<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4288<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4289according to the condition code given as <tt>cond</tt>. The comparison yields a
4290<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
4291identical type as the values being compared. The most significant bit in each
4292element is 1 if the element-wise comparison evaluates to true, and is 0
4293otherwise. All other bits of the result are undefined. The condition codes
4294are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4295instruction</a>.</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4296
4297<h5>Example:</h5>
4298<pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4299 &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>
4300 &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]4301</pre>
4302</div>
4303
4304<!-- _______________________________________________________________________ -->
4305<div class="doc_subsubsection">
4306 <a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
4307</div>
4308<div class="doc_text">
4309<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4310<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]4311<h5>Overview:</h5>
4312<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
4313element-wise comparison of its two floating point vector operands. The output
4314elements have the same width as the input elements.</p>
4315<h5>Arguments:</h5>
4316<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
4317the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4318a value, just a keyword. The possible condition code are:</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4319<ol>
4320 <li><tt>false</tt>: no comparison, always returns false</li>
4321 <li><tt>oeq</tt>: ordered and equal</li>
4322 <li><tt>ogt</tt>: ordered and greater than </li>
4323 <li><tt>oge</tt>: ordered and greater than or equal</li>
4324 <li><tt>olt</tt>: ordered and less than </li>
4325 <li><tt>ole</tt>: ordered and less than or equal</li>
4326 <li><tt>one</tt>: ordered and not equal</li>
4327 <li><tt>ord</tt>: ordered (no nans)</li>
4328 <li><tt>ueq</tt>: unordered or equal</li>
4329 <li><tt>ugt</tt>: unordered or greater than </li>
4330 <li><tt>uge</tt>: unordered or greater than or equal</li>
4331 <li><tt>ult</tt>: unordered or less than </li>
4332 <li><tt>ule</tt>: unordered or less than or equal</li>
4333 <li><tt>une</tt>: unordered or not equal</li>
4334 <li><tt>uno</tt>: unordered (either nans)</li>
4335 <li><tt>true</tt>: no comparison, always returns true</li>
4336</ol>
4337<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
4338<a href="#t_floating">floating point</a> typed. They must also be identical
4339types.</p>
4340<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4341<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4342according to the condition code given as <tt>cond</tt>. The comparison yields a
4343<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
4344an identical number of elements as the values being compared, and each element
4345having identical with to the width of the floating point elements. The most
4346significant bit in each element is 1 if the element-wise comparison evaluates to
4347true, and is 0 otherwise. All other bits of the result are undefined. The
4348condition codes are evaluated identically to the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4349<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4350
4351<h5>Example:</h5>
4352<pre>
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]4353 <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0, i32 -1 &gt;</i>
4354 &lt;result&gt; = vfcmp oeq &lt;2 x float&gt; &lt; float 4, float 0 &gt;, &lt; float 5, float 0 &gt;
4355
4356 <i>; yields: result=&lt;2 x i64&gt; &lt; i64 -1, i64 0 &gt;</i>
4357 &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]4358</pre>
4359</div>
4360
4361<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4362<div class="doc_subsubsection">
4363 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4364</div>
4365
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4366<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4367
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4368<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4369
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4370<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
4371<h5>Overview:</h5>
4372<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
4373the SSA graph representing the function.</p>
4374<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4375
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4376<p>The type of the incoming values is specified with the first type
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4377field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
4378as arguments, with one pair for each predecessor basic block of the
4379current block. Only values of <a href="#t_firstclass">first class</a>
4380type may be used as the value arguments to the PHI node. Only labels
4381may be used as the label arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4382
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4383<p>There must be no non-phi instructions between the start of a basic
4384block and the PHI instructions: i.e. PHI instructions must be first in
4385a basic block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4386
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4387<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4388
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4389<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
4390specified by the pair corresponding to the predecessor basic block that executed
4391just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4392
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4393<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4394<pre>
4395Loop: ; Infinite loop that counts from 0 on up...
4396 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4397 %nextindvar = add i32 %indvar, 1
4398 br label %Loop
4399</pre>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4400</div>
4401
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4402<!-- _______________________________________________________________________ -->
4403<div class="doc_subsubsection">
4404 <a name="i_select">'<tt>select</tt>' Instruction</a>
4405</div>
4406
4407<div class="doc_text">
4408
4409<h5>Syntax:</h5>
4410
4411<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4412 &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>
4413
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4414 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4415</pre>
4416
4417<h5>Overview:</h5>
4418
4419<p>
4420The '<tt>select</tt>' instruction is used to choose one value based on a
4421condition, without branching.
4422</p>
4423
4424
4425<h5>Arguments:</h5>
4426
4427<p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4428The '<tt>select</tt>' instruction requires an 'i1' value or
4429a vector of 'i1' values indicating the
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4430condition, and two values of the same <a href="#t_firstclass">first class</a>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4431type. If the val1/val2 are vectors and
4432the condition is a scalar, then entire vectors are selected, not
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4433individual elements.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4434</p>
4435
4436<h5>Semantics:</h5>
4437
4438<p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4439If 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]4440value argument; otherwise, it returns the second value argument.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4441</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4442<p>
4443If the condition is a vector of i1, then the value arguments must
4444be vectors of the same size, and the selection is done element
4445by element.
4446</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4447
4448<h5>Example:</h5>
4449
4450<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4451 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4452</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4453
4454<p>Note that the code generator does not yet support conditions
4455 with vector type.</p>
4456
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4457</div>
4458
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]4459
4460<!-- _______________________________________________________________________ -->
4461<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4462 <a name="i_call">'<tt>call</tt>' Instruction</a>
4463</div>
4464
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4465<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4466
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4467<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4468<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]4469 &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]4470</pre>
4471
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4472<h5>Overview:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4473
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4474<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4475
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4476<h5>Arguments:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4477
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4478<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4479
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4480<ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4481 <li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4482 <p>The optional "tail" marker indicates whether the callee function accesses
4483 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4484 function call is eligible for tail call optimization. Note that calls may
4485 be marked "tail" even if they do not occur before a <a
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4486 href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4487 </li>
4488 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4489 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4490 convention</a> the call should use. If none is specified, the call defaults
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4491 to using C calling conventions.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4492 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4493
4494 <li>
4495 <p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4496 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
4497 and '<tt>inreg</tt>' attributes are valid here.</p>
4498 </li>
4499
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4500 <li>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4501 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
4502 the type of the return value. Functions that return no value are marked
4503 <tt><a href="#t_void">void</a></tt>.</p>
4504 </li>
4505 <li>
4506 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
4507 value being invoked. The argument types must match the types implied by
4508 this signature. This type can be omitted if the function is not varargs
4509 and if the function type does not return a pointer to a function.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4510 </li>
4511 <li>
4512 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4513 be invoked. In most cases, this is a direct function invocation, but
4514 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4515 to function value.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4516 </li>
4517 <li>
4518 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencera7e302a2005-05-01 22:22:57 +0000[diff] [blame]4519 function signature argument types. All arguments must be of
4520 <a href="#t_firstclass">first class</a> type. If the function signature
4521 indicates the function accepts a variable number of arguments, the extra
4522 arguments can be specified.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4523 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4524 <li>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]4525 <p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4526 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
4527 '<tt>readnone</tt>' attributes are valid here.</p>
4528 </li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4529</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4530
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4531<h5>Semantics:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4532
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4533<p>The '<tt>call</tt>' instruction is used to cause control flow to
4534transfer to a specified function, with its incoming arguments bound to
4535the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
4536instruction in the called function, control flow continues with the
4537instruction after the function call, and the return value of the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4538function is bound to the result argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4539
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4540<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4541
4542<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4543 %retval = call i32 @test(i32 %argc)
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]4544 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4545 %X = tail call i32 @foo() <i>; yields i32</i>
4546 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4547 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]4548
4549 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4550 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]4551 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
4552 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]4553 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]4554 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4555</pre>
4556
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4557</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4558
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4559<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4560<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]4561 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4562</div>
4563
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4564<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4565
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4566<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4567
4568<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4569 &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]4570</pre>
4571
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4572<h5>Overview:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4573
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4574<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4575the "variable argument" area of a function call. It is used to implement the
4576<tt>va_arg</tt> macro in C.</p>
4577
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4578<h5>Arguments:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4579
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4580<p>This instruction takes a <tt>va_list*</tt> value and the type of
4581the argument. It returns a value of the specified argument type and
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4582increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4583actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4584
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4585<h5>Semantics:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4586
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4587<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
4588type from the specified <tt>va_list</tt> and causes the
4589<tt>va_list</tt> to point to the next argument. For more information,
4590see the variable argument handling <a href="#int_varargs">Intrinsic
4591Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4592
4593<p>It is legal for this instruction to be called in a function which does not
4594take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4595function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4596
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4597<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4598href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4599argument.</p>
4600
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4601<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4602
4603<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4604
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]4605<p>Note that the code generator does not yet fully support va_arg
4606 on many targets. Also, it does not currently support va_arg with
4607 aggregate types on any target.</p>
4608
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4609</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4610
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4611<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4612<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4613<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4614
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4615<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4616
4617<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4618well known names and semantics and are required to follow certain restrictions.
4619Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4620language that does not require changing all of the transformations in LLVM when
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]4621adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4622
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4623<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4624prefix is reserved in LLVM for intrinsic names; thus, function names may not
4625begin with this prefix. Intrinsic functions must always be external functions:
4626you cannot define the body of intrinsic functions. Intrinsic functions may
4627only be used in call or invoke instructions: it is illegal to take the address
4628of an intrinsic function. Additionally, because intrinsic functions are part
4629of the LLVM language, it is required if any are added that they be documented
4630here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4631
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4632<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
4633a family of functions that perform the same operation but on different data
4634types. Because LLVM can represent over 8 million different integer types,
4635overloading is used commonly to allow an intrinsic function to operate on any
4636integer type. One or more of the argument types or the result type can be
4637overloaded to accept any integer type. Argument types may also be defined as
4638exactly matching a previous argument's type or the result type. This allows an
4639intrinsic function which accepts multiple arguments, but needs all of them to
4640be of the same type, to only be overloaded with respect to a single argument or
4641the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4642
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4643<p>Overloaded intrinsics will have the names of its overloaded argument types
4644encoded into its function name, each preceded by a period. Only those types
4645which are overloaded result in a name suffix. Arguments whose type is matched
4646against another type do not. For example, the <tt>llvm.ctpop</tt> function can
4647take an integer of any width and returns an integer of exactly the same integer
4648width. This leads to a family of functions such as
4649<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
4650Only one type, the return type, is overloaded, and only one type suffix is
4651required. Because the argument's type is matched against the return type, it
4652does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4653
4654<p>To learn how to add an intrinsic function, please see the
4655<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4656</p>
4657
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4658</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4659
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4660<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4661<div class="doc_subsection">
4662 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
4663</div>
4664
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4665<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4666
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4667<p>Variable argument support is defined in LLVM with the <a
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]4668 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4669intrinsic functions. These functions are related to the similarly
4670named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4671
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4672<p>All of these functions operate on arguments that use a
4673target-specific value type "<tt>va_list</tt>". The LLVM assembly
4674language reference manual does not define what this type is, so all
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4675transformations should be prepared to handle these functions regardless of
4676the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4677
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]4678<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]4679instruction and the variable argument handling intrinsic functions are
4680used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4681
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4682<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4683<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4684define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4685 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4686 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4687 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4688 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4689
4690 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4691 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4692
4693 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4694 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4695 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4696 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4697 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4698
4699 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4700 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4701 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4702}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4703
4704declare void @llvm.va_start(i8*)
4705declare void @llvm.va_copy(i8*, i8*)
4706declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4707</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4708</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4709
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4710</div>
4711
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4712<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4713<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4714 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4715</div>
4716
4717
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4718<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4719<h5>Syntax:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4720<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4721<h5>Overview:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4722<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4723<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
4724href="#i_va_arg">va_arg</a></tt>.</p>
4725
4726<h5>Arguments:</h5>
4727
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4728<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]4729
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4730<h5>Semantics:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4731
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4732<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]4733macro available in C. In a target-dependent way, it initializes the
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4734<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]4735<tt>va_arg</tt> will produce the first variable argument passed to the function.
4736Unlike 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]4737last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4738
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4739</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4740
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4741<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4742<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4743 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4744</div>
4745
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4746<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4747<h5>Syntax:</h5>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4748<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4749<h5>Overview:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4750
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4751<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4752which 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]4753or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4754
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4755<h5>Arguments:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4756
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4757<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]4758
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4759<h5>Semantics:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4760
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4761<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]4762macro available in C. In a target-dependent way, it destroys the
4763<tt>va_list</tt> element to which the argument points. Calls to <a
4764href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
4765<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
4766<tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4767
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4768</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4769
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4770<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4771<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4772 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4773</div>
4774
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4775<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4776
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4777<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4778
4779<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4780 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4781</pre>
4782
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4783<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4784
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4785<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
4786from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4787
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4788<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4789
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4790<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]4791The 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]4792
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4793
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4794<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4795
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4796<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
4797macro available in C. In a target-dependent way, it copies the source
4798<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
4799intrinsic is necessary because the <tt><a href="#int_va_start">
4800llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
4801example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4802
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4803</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4804
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4805<!-- ======================================================================= -->
4806<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4807 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
4808</div>
4809
4810<div class="doc_text">
4811
4812<p>
4813LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]4814Collection</a> (GC) requires the implementation and generation of these
4815intrinsics.
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4816These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4817stack</a>, as well as garbage collector implementations that require <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4818href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4819Front-ends for type-safe garbage collected languages should generate these
4820intrinsics to make use of the LLVM garbage collectors. For more details, see <a
4821href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
4822</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]4823
4824<p>The garbage collection intrinsics only operate on objects in the generic
4825 address space (address space zero).</p>
4826
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4827</div>
4828
4829<!-- _______________________________________________________________________ -->
4830<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4831 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4832</div>
4833
4834<div class="doc_text">
4835
4836<h5>Syntax:</h5>
4837
4838<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4839 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4840</pre>
4841
4842<h5>Overview:</h5>
4843
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]4844<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]4845the code generator, and allows some metadata to be associated with it.</p>
4846
4847<h5>Arguments:</h5>
4848
4849<p>The first argument specifies the address of a stack object that contains the
4850root pointer. The second pointer (which must be either a constant or a global
4851value address) contains the meta-data to be associated with the root.</p>
4852
4853<h5>Semantics:</h5>
4854
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]4855<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]4856location. At compile-time, the code generator generates information to allow
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4857the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
4858intrinsic may only be used in a function which <a href="#gc">specifies a GC
4859algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4860
4861</div>
4862
4863
4864<!-- _______________________________________________________________________ -->
4865<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4866 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4867</div>
4868
4869<div class="doc_text">
4870
4871<h5>Syntax:</h5>
4872
4873<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4874 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4875</pre>
4876
4877<h5>Overview:</h5>
4878
4879<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4880locations, allowing garbage collector implementations that require read
4881barriers.</p>
4882
4883<h5>Arguments:</h5>
4884
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4885<p>The second argument is the address to read from, which should be an address
4886allocated from the garbage collector. The first object is a pointer to the
4887start of the referenced object, if needed by the language runtime (otherwise
4888null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4889
4890<h5>Semantics:</h5>
4891
4892<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4893instruction, but may be replaced with substantially more complex code by the
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4894garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
4895may only be used in a function which <a href="#gc">specifies a GC
4896algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4897
4898</div>
4899
4900
4901<!-- _______________________________________________________________________ -->
4902<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4903 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4904</div>
4905
4906<div class="doc_text">
4907
4908<h5>Syntax:</h5>
4909
4910<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4911 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4912</pre>
4913
4914<h5>Overview:</h5>
4915
4916<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4917locations, allowing garbage collector implementations that require write
4918barriers (such as generational or reference counting collectors).</p>
4919
4920<h5>Arguments:</h5>
4921
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4922<p>The first argument is the reference to store, the second is the start of the
4923object to store it to, and the third is the address of the field of Obj to
4924store to. If the runtime does not require a pointer to the object, Obj may be
4925null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4926
4927<h5>Semantics:</h5>
4928
4929<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4930instruction, but may be replaced with substantially more complex code by the
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4931garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
4932may only be used in a function which <a href="#gc">specifies a GC
4933algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4934
4935</div>
4936
4937
4938
4939<!-- ======================================================================= -->
4940<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4941 <a name="int_codegen">Code Generator Intrinsics</a>
4942</div>
4943
4944<div class="doc_text">
4945<p>
4946These intrinsics are provided by LLVM to expose special features that may only
4947be implemented with code generator support.
4948</p>
4949
4950</div>
4951
4952<!-- _______________________________________________________________________ -->
4953<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4954 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4955</div>
4956
4957<div class="doc_text">
4958
4959<h5>Syntax:</h5>
4960<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4961 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4962</pre>
4963
4964<h5>Overview:</h5>
4965
4966<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4967The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4968target-specific value indicating the return address of the current function
4969or one of its callers.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4970</p>
4971
4972<h5>Arguments:</h5>
4973
4974<p>
4975The argument to this intrinsic indicates which function to return the address
4976for. Zero indicates the calling function, one indicates its caller, etc. The
4977argument is <b>required</b> to be a constant integer value.
4978</p>
4979
4980<h5>Semantics:</h5>
4981
4982<p>
4983The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4984the return address of the specified call frame, or zero if it cannot be
4985identified. The value returned by this intrinsic is likely to be incorrect or 0
4986for arguments other than zero, so it should only be used for debugging purposes.
4987</p>
4988
4989<p>
4990Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4991aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4992source-language caller.
4993</p>
4994</div>
4995
4996
4997<!-- _______________________________________________________________________ -->
4998<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4999 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5000</div>
5001
5002<div class="doc_text">
5003
5004<h5>Syntax:</h5>
5005<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5006 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5007</pre>
5008
5009<h5>Overview:</h5>
5010
5011<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]5012The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5013target-specific frame pointer value for the specified stack frame.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5014</p>
5015
5016<h5>Arguments:</h5>
5017
5018<p>
5019The argument to this intrinsic indicates which function to return the frame
5020pointer for. Zero indicates the calling function, one indicates its caller,
5021etc. The argument is <b>required</b> to be a constant integer value.
5022</p>
5023
5024<h5>Semantics:</h5>
5025
5026<p>
5027The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
5028the frame address of the specified call frame, or zero if it cannot be
5029identified. The value returned by this intrinsic is likely to be incorrect or 0
5030for arguments other than zero, so it should only be used for debugging purposes.
5031</p>
5032
5033<p>
5034Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]5035aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5036source-language caller.
5037</p>
5038</div>
5039
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5040<!-- _______________________________________________________________________ -->
5041<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5042 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5043</div>
5044
5045<div class="doc_text">
5046
5047<h5>Syntax:</h5>
5048<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5049 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5050</pre>
5051
5052<h5>Overview:</h5>
5053
5054<p>
5055The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5056the function stack, for use with <a href="#int_stackrestore">
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5057<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
5058features like scoped automatic variable sized arrays in C99.
5059</p>
5060
5061<h5>Semantics:</h5>
5062
5063<p>
5064This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5065href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5066<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
5067<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
5068state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
5069practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
5070that were allocated after the <tt>llvm.stacksave</tt> was executed.
5071</p>
5072
5073</div>
5074
5075<!-- _______________________________________________________________________ -->
5076<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5077 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5078</div>
5079
5080<div class="doc_text">
5081
5082<h5>Syntax:</h5>
5083<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5084 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5085</pre>
5086
5087<h5>Overview:</h5>
5088
5089<p>
5090The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5091the function stack to the state it was in when the corresponding <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5092href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5093useful for implementing language features like scoped automatic variable sized
5094arrays in C99.
5095</p>
5096
5097<h5>Semantics:</h5>
5098
5099<p>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5100See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5101</p>
5102
5103</div>
5104
5105
5106<!-- _______________________________________________________________________ -->
5107<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5108 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5109</div>
5110
5111<div class="doc_text">
5112
5113<h5>Syntax:</h5>
5114<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5115 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]5116</pre>
5117
5118<h5>Overview:</h5>
5119
5120
5121<p>
5122The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5123a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
5124no
5125effect on the behavior of the program but can change its performance
Chris Lattner2a615362005-02-28 19:47:14 +0000[diff] [blame]5126characteristics.
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5127</p>
5128
5129<h5>Arguments:</h5>
5130
5131<p>
5132<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
5133determining if the fetch should be for a read (0) or write (1), and
5134<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattneraeffb4a2005-03-07 20:31:38 +0000[diff] [blame]5135locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5136<tt>locality</tt> arguments must be constant integers.
5137</p>
5138
5139<h5>Semantics:</h5>
5140
5141<p>
5142This intrinsic does not modify the behavior of the program. In particular,
5143prefetches cannot trap and do not produce a value. On targets that support this
5144intrinsic, the prefetch can provide hints to the processor cache for better
5145performance.
5146</p>
5147
5148</div>
5149
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5150<!-- _______________________________________________________________________ -->
5151<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5152 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5153</div>
5154
5155<div class="doc_text">
5156
5157<h5>Syntax:</h5>
5158<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5159 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5160</pre>
5161
5162<h5>Overview:</h5>
5163
5164
5165<p>
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5166The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5167(PC) in a region of
5168code to simulators and other tools. The method is target specific, but it is
5169expected that the marker will use exported symbols to transmit the PC of the
5170marker.
5171The marker makes no guarantees that it will remain with any specific instruction
5172after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb3e7afd2006-03-24 07:16:10 +0000[diff] [blame]5173optimizations. The intended use is to be inserted after optimizations to allow
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5174correlations of simulation runs.
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5175</p>
5176
5177<h5>Arguments:</h5>
5178
5179<p>
5180<tt>id</tt> is a numerical id identifying the marker.
5181</p>
5182
5183<h5>Semantics:</h5>
5184
5185<p>
5186This intrinsic does not modify the behavior of the program. Backends that do not
5187support this intrinisic may ignore it.
5188</p>
5189
5190</div>
5191
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5192<!-- _______________________________________________________________________ -->
5193<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5194 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5195</div>
5196
5197<div class="doc_text">
5198
5199<h5>Syntax:</h5>
5200<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5201 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5202</pre>
5203
5204<h5>Overview:</h5>
5205
5206
5207<p>
5208The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5209counter register (or similar low latency, high accuracy clocks) on those targets
5210that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
5211As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
5212should only be used for small timings.
5213</p>
5214
5215<h5>Semantics:</h5>
5216
5217<p>
5218When directly supported, reading the cycle counter should not modify any memory.
5219Implementations are allowed to either return a application specific value or a
5220system wide value. On backends without support, this is lowered to a constant 0.
5221</p>
5222
5223</div>
5224
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5225<!-- ======================================================================= -->
5226<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5227 <a name="int_libc">Standard C Library Intrinsics</a>
5228</div>
5229
5230<div class="doc_text">
5231<p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5232LLVM provides intrinsics for a few important standard C library functions.
5233These intrinsics allow source-language front-ends to pass information about the
5234alignment of the pointer arguments to the code generator, providing opportunity
5235for more efficient code generation.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5236</p>
5237
5238</div>
5239
5240<!-- _______________________________________________________________________ -->
5241<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5242 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5243</div>
5244
5245<div class="doc_text">
5246
5247<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5248<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
5249width. Not all targets support all bit widths however.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5250<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5251 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5252 i8 &lt;len&gt;, i32 &lt;align&gt;)
5253 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5254 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5255 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5256 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5257 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5258 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5259</pre>
5260
5261<h5>Overview:</h5>
5262
5263<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5264The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5265location to the destination location.
5266</p>
5267
5268<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5269Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5270intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5271</p>
5272
5273<h5>Arguments:</h5>
5274
5275<p>
5276The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5277the source. The third argument is an integer argument
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5278specifying the number of bytes to copy, and the fourth argument is the alignment
5279of the source and destination locations.
5280</p>
5281
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5282<p>
5283If 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]5284the caller guarantees that both the source and destination pointers are aligned
5285to that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5286</p>
5287
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5288<h5>Semantics:</h5>
5289
5290<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5291The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5292location to the destination location, which are not allowed to overlap. It
5293copies "len" bytes of memory over. If the argument is known to be aligned to
5294some boundary, this can be specified as the fourth argument, otherwise it should
5295be set to 0 or 1.
5296</p>
5297</div>
5298
5299
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5300<!-- _______________________________________________________________________ -->
5301<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5302 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5303</div>
5304
5305<div class="doc_text">
5306
5307<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5308<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
5309width. Not all targets support all bit widths however.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5310<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5311 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5312 i8 &lt;len&gt;, i32 &lt;align&gt;)
5313 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5314 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5315 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5316 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5317 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5318 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5319</pre>
5320
5321<h5>Overview:</h5>
5322
5323<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5324The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
5325location to the destination location. It is similar to the
Chris Lattner4b2cbcf2008-01-06 19:51:52 +0000[diff] [blame]5326'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5327</p>
5328
5329<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5330Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5331intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5332</p>
5333
5334<h5>Arguments:</h5>
5335
5336<p>
5337The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5338the source. The third argument is an integer argument
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5339specifying the number of bytes to copy, and the fourth argument is the alignment
5340of the source and destination locations.
5341</p>
5342
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5343<p>
5344If 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]5345the caller guarantees that the source and destination pointers are aligned to
5346that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5347</p>
5348
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5349<h5>Semantics:</h5>
5350
5351<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5352The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5353location to the destination location, which may overlap. It
5354copies "len" bytes of memory over. If the argument is known to be aligned to
5355some boundary, this can be specified as the fourth argument, otherwise it should
5356be set to 0 or 1.
5357</p>
5358</div>
5359
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5360
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5361<!-- _______________________________________________________________________ -->
5362<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5363 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5364</div>
5365
5366<div class="doc_text">
5367
5368<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5369<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
5370width. Not all targets support all bit widths however.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5371<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5372 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5373 i8 &lt;len&gt;, i32 &lt;align&gt;)
5374 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5375 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5376 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5377 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5378 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5379 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5380</pre>
5381
5382<h5>Overview:</h5>
5383
5384<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5385The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5386byte value.
5387</p>
5388
5389<p>
5390Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
5391does not return a value, and takes an extra alignment argument.
5392</p>
5393
5394<h5>Arguments:</h5>
5395
5396<p>
5397The first argument is a pointer to the destination to fill, the second is the
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5398byte value to fill it with, the third argument is an integer
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5399argument specifying the number of bytes to fill, and the fourth argument is the
5400known alignment of destination location.
5401</p>
5402
5403<p>
5404If 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]5405the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5406</p>
5407
5408<h5>Semantics:</h5>
5409
5410<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5411The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
5412the
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5413destination location. If the argument is known to be aligned to some boundary,
5414this can be specified as the fourth argument, otherwise it should be set to 0 or
54151.
5416</p>
5417</div>
5418
5419
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5420<!-- _______________________________________________________________________ -->
5421<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5422 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5423</div>
5424
5425<div class="doc_text">
5426
5427<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5428<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]5429floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5430types however.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5431<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5432 declare float @llvm.sqrt.f32(float %Val)
5433 declare double @llvm.sqrt.f64(double %Val)
5434 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5435 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5436 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5437</pre>
5438
5439<h5>Overview:</h5>
5440
5441<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5442The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5443returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5444<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner103e2d72008-01-29 07:00:44 +0000[diff] [blame]5445negative numbers other than -0.0 (which allows for better optimization, because
5446there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
5447defined to return -0.0 like IEEE sqrt.
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5448</p>
5449
5450<h5>Arguments:</h5>
5451
5452<p>
5453The argument and return value are floating point numbers of the same type.
5454</p>
5455
5456<h5>Semantics:</h5>
5457
5458<p>
Dan Gohmand6257fe2007-07-16 14:37:41 +0000[diff] [blame]5459This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5460floating point number.
5461</p>
5462</div>
5463
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5464<!-- _______________________________________________________________________ -->
5465<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5466 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5467</div>
5468
5469<div class="doc_text">
5470
5471<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5472<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]5473floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5474types however.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5475<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5476 declare float @llvm.powi.f32(float %Val, i32 %power)
5477 declare double @llvm.powi.f64(double %Val, i32 %power)
5478 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5479 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5480 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5481</pre>
5482
5483<h5>Overview:</h5>
5484
5485<p>
5486The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5487specified (positive or negative) power. The order of evaluation of
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5488multiplications is not defined. When a vector of floating point type is
5489used, the second argument remains a scalar integer value.
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5490</p>
5491
5492<h5>Arguments:</h5>
5493
5494<p>
5495The second argument is an integer power, and the first is a value to raise to
5496that power.
5497</p>
5498
5499<h5>Semantics:</h5>
5500
5501<p>
5502This function returns the first value raised to the second power with an
5503unspecified sequence of rounding operations.</p>
5504</div>
5505
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5506<!-- _______________________________________________________________________ -->
5507<div class="doc_subsubsection">
5508 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5509</div>
5510
5511<div class="doc_text">
5512
5513<h5>Syntax:</h5>
5514<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5515floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5516types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5517<pre>
5518 declare float @llvm.sin.f32(float %Val)
5519 declare double @llvm.sin.f64(double %Val)
5520 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5521 declare fp128 @llvm.sin.f128(fp128 %Val)
5522 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5523</pre>
5524
5525<h5>Overview:</h5>
5526
5527<p>
5528The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
5529</p>
5530
5531<h5>Arguments:</h5>
5532
5533<p>
5534The argument and return value are floating point numbers of the same type.
5535</p>
5536
5537<h5>Semantics:</h5>
5538
5539<p>
5540This function returns the sine of the specified operand, returning the
5541same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5542conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5543</div>
5544
5545<!-- _______________________________________________________________________ -->
5546<div class="doc_subsubsection">
5547 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5548</div>
5549
5550<div class="doc_text">
5551
5552<h5>Syntax:</h5>
5553<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5554floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5555types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5556<pre>
5557 declare float @llvm.cos.f32(float %Val)
5558 declare double @llvm.cos.f64(double %Val)
5559 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5560 declare fp128 @llvm.cos.f128(fp128 %Val)
5561 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5562</pre>
5563
5564<h5>Overview:</h5>
5565
5566<p>
5567The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
5568</p>
5569
5570<h5>Arguments:</h5>
5571
5572<p>
5573The argument and return value are floating point numbers of the same type.
5574</p>
5575
5576<h5>Semantics:</h5>
5577
5578<p>
5579This function returns the cosine of the specified operand, returning the
5580same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5581conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5582</div>
5583
5584<!-- _______________________________________________________________________ -->
5585<div class="doc_subsubsection">
5586 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5587</div>
5588
5589<div class="doc_text">
5590
5591<h5>Syntax:</h5>
5592<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5593floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5594types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5595<pre>
5596 declare float @llvm.pow.f32(float %Val, float %Power)
5597 declare double @llvm.pow.f64(double %Val, double %Power)
5598 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5599 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5600 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5601</pre>
5602
5603<h5>Overview:</h5>
5604
5605<p>
5606The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5607specified (positive or negative) power.
5608</p>
5609
5610<h5>Arguments:</h5>
5611
5612<p>
5613The second argument is a floating point power, and the first is a value to
5614raise to that power.
5615</p>
5616
5617<h5>Semantics:</h5>
5618
5619<p>
5620This function returns the first value raised to the second power,
5621returning the
5622same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5623conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5624</div>
5625
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5626
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5627<!-- ======================================================================= -->
5628<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5629 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5630</div>
5631
5632<div class="doc_text">
5633<p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5634LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5635These allow efficient code generation for some algorithms.
5636</p>
5637
5638</div>
5639
5640<!-- _______________________________________________________________________ -->
5641<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5642 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5643</div>
5644
5645<div class="doc_text">
5646
5647<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5648<p>This is an overloaded intrinsic function. You can use bswap on any integer
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5649type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5650<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5651 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5652 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5653 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5654</pre>
5655
5656<h5>Overview:</h5>
5657
5658<p>
Reid Spencer338ea092007-04-02 02:25:19 +0000[diff] [blame]5659The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5660values with an even number of bytes (positive multiple of 16 bits). These are
5661useful for performing operations on data that is not in the target's native
5662byte order.
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5663</p>
5664
5665<h5>Semantics:</h5>
5666
5667<p>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5668The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5669and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
5670intrinsic returns an i32 value that has the four bytes of the input i32
5671swapped, 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]5672i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
5673<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5674additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5675</p>
5676
5677</div>
5678
5679<!-- _______________________________________________________________________ -->
5680<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5681 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5682</div>
5683
5684<div class="doc_text">
5685
5686<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5687<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]5688width. Not all targets support all bit widths however.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5689<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5690 declare i8 @llvm.ctpop.i8 (i8 &lt;src&gt;)
5691 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5692 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5693 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5694 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5695</pre>
5696
5697<h5>Overview:</h5>
5698
5699<p>
Chris Lattnerec6cb612006-01-16 22:38:59 +0000[diff] [blame]5700The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
5701value.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5702</p>
5703
5704<h5>Arguments:</h5>
5705
5706<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]5707The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5708integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5709</p>
5710
5711<h5>Semantics:</h5>
5712
5713<p>
5714The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
5715</p>
5716</div>
5717
5718<!-- _______________________________________________________________________ -->
5719<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5720 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5721</div>
5722
5723<div class="doc_text">
5724
5725<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5726<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]5727integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5728<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5729 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5730 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5731 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5732 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5733 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5734</pre>
5735
5736<h5>Overview:</h5>
5737
5738<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5739The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5740leading zeros in a variable.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5741</p>
5742
5743<h5>Arguments:</h5>
5744
5745<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]5746The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5747integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5748</p>
5749
5750<h5>Semantics:</h5>
5751
5752<p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5753The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
5754in 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]5755of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5756</p>
5757</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5758
5759
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5760
5761<!-- _______________________________________________________________________ -->
5762<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5763 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5764</div>
5765
5766<div class="doc_text">
5767
5768<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5769<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]5770integer bit width. Not all targets support all bit widths however.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5771<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5772 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5773 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5774 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5775 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5776 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5777</pre>
5778
5779<h5>Overview:</h5>
5780
5781<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5782The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5783trailing zeros.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5784</p>
5785
5786<h5>Arguments:</h5>
5787
5788<p>
5789The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5790integer type. The return type must match the argument type.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5791</p>
5792
5793<h5>Semantics:</h5>
5794
5795<p>
5796The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
5797in a variable. If the src == 0 then the result is the size in bits of the type
5798of src. For example, <tt>llvm.cttz(2) = 1</tt>.
5799</p>
5800</div>
5801
Reid Spencer497d93e2007-04-01 08:27:01 +0000[diff] [blame]5802<!-- _______________________________________________________________________ -->
5803<div class="doc_subsubsection">
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5804 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5805</div>
5806
5807<div class="doc_text">
5808
5809<h5>Syntax:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5810<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5811on any integer bit width.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5812<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5813 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
5814 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5815</pre>
5816
5817<h5>Overview:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5818<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5819range of bits from an integer value and returns them in the same bit width as
5820the original value.</p>
5821
5822<h5>Arguments:</h5>
5823<p>The first argument, <tt>%val</tt> and the result may be integer types of
5824any bit width but they must have the same bit width. The second and third
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5825arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5826
5827<h5>Semantics:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5828<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5829of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
5830<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
5831operates in forward mode.</p>
5832<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
5833right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5834only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
5835<ol>
5836 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
5837 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
5838 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
5839 to determine the number of bits to retain.</li>
5840 <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]5841 <li>The mask is ANDed with <tt>%val</tt> to produce the result.</li>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5842</ol>
Reid Spencerd6a85b52007-05-14 16:14:57 +0000[diff] [blame]5843<p>In reverse mode, a similar computation is made except that the bits are
5844returned in the reverse order. So, for example, if <tt>X</tt> has the value
5845<tt>i16 0x0ACF (101011001111)</tt> and we apply
5846<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
5847<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5848</div>
5849
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5850<div class="doc_subsubsection">
5851 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
5852</div>
5853
5854<div class="doc_text">
5855
5856<h5>Syntax:</h5>
5857<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5858on any integer bit width.</p>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5859<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5860 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
5861 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]5862</pre>
5863
5864<h5>Overview:</h5>
5865<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
5866of bits in an integer value with another integer value. It returns the integer
5867with the replaced bits.</p>
5868
5869<h5>Arguments:</h5>
5870<p>The first argument, <tt>%val</tt> and the result may be integer types of
5871any bit width but they must have the same bit width. <tt>%val</tt> is the value
5872whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
5873integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
5874type since they specify only a bit index.</p>
5875
5876<h5>Semantics:</h5>
5877<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
5878of operation: forwards and reverse. If <tt>%lo</tt> is greater than
5879<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
5880operates in forward mode.</p>
5881<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
5882truncating it down to the size of the replacement area or zero extending it
5883up to that size.</p>
5884<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5885are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5886in <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]5887to the <tt>%hi</tt>th bit.</p>
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5888<p>In reverse mode, a similar computation is made except that the bits are
5889reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5890<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.</p>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5891<h5>Examples:</h5>
5892<pre>
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5893 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5894 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5895 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5896 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5897 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]5898</pre>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5899</div>
5900
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5901<!-- ======================================================================= -->
5902<div class="doc_subsection">
5903 <a name="int_debugger">Debugger Intrinsics</a>
5904</div>
5905
5906<div class="doc_text">
5907<p>
5908The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
5909are described in the <a
5910href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
5911Debugging</a> document.
5912</p>
5913</div>
5914
5915
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]5916<!-- ======================================================================= -->
5917<div class="doc_subsection">
5918 <a name="int_eh">Exception Handling Intrinsics</a>
5919</div>
5920
5921<div class="doc_text">
5922<p> The LLVM exception handling intrinsics (which all start with
5923<tt>llvm.eh.</tt> prefix), are described in the <a
5924href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
5925Handling</a> document. </p>
5926</div>
5927
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5928<!-- ======================================================================= -->
5929<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5930 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5931</div>
5932
5933<div class="doc_text">
5934<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5935 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5936 the <tt>nest</tt> attribute, from a function. The result is a callable
5937 function pointer lacking the nest parameter - the caller does not need
5938 to provide a value for it. Instead, the value to use is stored in
5939 advance in a "trampoline", a block of memory usually allocated
5940 on the stack, which also contains code to splice the nest value into the
5941 argument list. This is used to implement the GCC nested function address
5942 extension.
5943</p>
5944<p>
5945 For example, if the function is
5946 <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]5947 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]5948<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5949 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
5950 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
5951 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
5952 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5953</pre>
Bill Wendling03295ca2007-09-22 09:23:55 +0000[diff] [blame]5954 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
5955 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5956</div>
5957
5958<!-- _______________________________________________________________________ -->
5959<div class="doc_subsubsection">
5960 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
5961</div>
5962<div class="doc_text">
5963<h5>Syntax:</h5>
5964<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5965declare 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]5966</pre>
5967<h5>Overview:</h5>
5968<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5969 This fills the memory pointed to by <tt>tramp</tt> with code
5970 and returns a function pointer suitable for executing it.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5971</p>
5972<h5>Arguments:</h5>
5973<p>
5974 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
5975 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
5976 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsc00c2ba2007-08-22 23:39:54 +0000[diff] [blame]5977 intrinsic. Note that the size and the alignment are target-specific - LLVM
5978 currently provides no portable way of determining them, so a front-end that
5979 generates this intrinsic needs to have some target-specific knowledge.
5980 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]5981</p>
5982<h5>Semantics:</h5>
5983<p>
5984 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5985 dependent code, turning it into a function. A pointer to this function is
5986 returned, but needs to be bitcast to an
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5987 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5988 before being called. The new function's signature is the same as that of
5989 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
5990 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
5991 of pointer type. Calling the new function is equivalent to calling
5992 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
5993 missing <tt>nest</tt> argument. If, after calling
5994 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
5995 modified, then the effect of any later call to the returned function pointer is
5996 undefined.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5997</p>
5998</div>
5999
6000<!-- ======================================================================= -->
6001<div class="doc_subsection">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6002 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
6003</div>
6004
6005<div class="doc_text">
6006<p>
6007 These intrinsic functions expand the "universal IR" of LLVM to represent
6008 hardware constructs for atomic operations and memory synchronization. This
6009 provides an interface to the hardware, not an interface to the programmer. It
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]6010 is aimed at a low enough level to allow any programming models or APIs
6011 (Application Programming Interfaces) which
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6012 need atomic behaviors to map cleanly onto it. It is also modeled primarily on
6013 hardware behavior. Just as hardware provides a "universal IR" for source
6014 languages, it also provides a starting point for developing a "universal"
6015 atomic operation and synchronization IR.
6016</p>
6017<p>
6018 These do <em>not</em> form an API such as high-level threading libraries,
6019 software transaction memory systems, atomic primitives, and intrinsic
6020 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
6021 application libraries. The hardware interface provided by LLVM should allow
6022 a clean implementation of all of these APIs and parallel programming models.
6023 No one model or paradigm should be selected above others unless the hardware
6024 itself ubiquitously does so.
6025
6026</p>
6027</div>
6028
6029<!-- _______________________________________________________________________ -->
6030<div class="doc_subsubsection">
6031 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
6032</div>
6033<div class="doc_text">
6034<h5>Syntax:</h5>
6035<pre>
6036declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;,
6037i1 &lt;device&gt; )
6038
6039</pre>
6040<h5>Overview:</h5>
6041<p>
6042 The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
6043 specific pairs of memory access types.
6044</p>
6045<h5>Arguments:</h5>
6046<p>
6047 The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
6048 The first four arguments enables a specific barrier as listed below. The fith
6049 argument specifies that the barrier applies to io or device or uncached memory.
6050
6051</p>
6052 <ul>
6053 <li><tt>ll</tt>: load-load barrier</li>
6054 <li><tt>ls</tt>: load-store barrier</li>
6055 <li><tt>sl</tt>: store-load barrier</li>
6056 <li><tt>ss</tt>: store-store barrier</li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6057 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6058 </ul>
6059<h5>Semantics:</h5>
6060<p>
6061 This intrinsic causes the system to enforce some ordering constraints upon
6062 the loads and stores of the program. This barrier does not indicate
6063 <em>when</em> any events will occur, it only enforces an <em>order</em> in
6064 which they occur. For any of the specified pairs of load and store operations
6065 (f.ex. load-load, or store-load), all of the first operations preceding the
6066 barrier will complete before any of the second operations succeeding the
6067 barrier begin. Specifically the semantics for each pairing is as follows:
6068</p>
6069 <ul>
6070 <li><tt>ll</tt>: All loads before the barrier must complete before any load
6071 after the barrier begins.</li>
6072
6073 <li><tt>ls</tt>: All loads before the barrier must complete before any
6074 store after the barrier begins.</li>
6075 <li><tt>ss</tt>: All stores before the barrier must complete before any
6076 store after the barrier begins.</li>
6077 <li><tt>sl</tt>: All stores before the barrier must complete before any
6078 load after the barrier begins.</li>
6079 </ul>
6080<p>
6081 These semantics are applied with a logical "and" behavior when more than one
6082 is enabled in a single memory barrier intrinsic.
6083</p>
6084<p>
6085 Backends may implement stronger barriers than those requested when they do not
6086 support as fine grained a barrier as requested. Some architectures do not
6087 need all types of barriers and on such architectures, these become noops.
6088</p>
6089<h5>Example:</h5>
6090<pre>
6091%ptr = malloc i32
6092 store i32 4, %ptr
6093
6094%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
6095 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
6096 <i>; guarantee the above finishes</i>
6097 store i32 8, %ptr <i>; before this begins</i>
6098</pre>
6099</div>
6100
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6101<!-- _______________________________________________________________________ -->
6102<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6103 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6104</div>
6105<div class="doc_text">
6106<h5>Syntax:</h5>
6107<p>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6108 This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
6109 any integer bit width and for different address spaces. Not all targets
6110 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6111
6112<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6113declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6114declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6115declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
6116declare 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]6117
6118</pre>
6119<h5>Overview:</h5>
6120<p>
6121 This loads a value in memory and compares it to a given value. If they are
6122 equal, it stores a new value into the memory.
6123</p>
6124<h5>Arguments:</h5>
6125<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6126 The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6127 well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
6128 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
6129 this integer type. While any bit width integer may be used, targets may only
6130 lower representations they support in hardware.
6131
6132</p>
6133<h5>Semantics:</h5>
6134<p>
6135 This entire intrinsic must be executed atomically. It first loads the value
6136 in memory pointed to by <tt>ptr</tt> and compares it with the value
6137 <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
6138 loaded value is yielded in all cases. This provides the equivalent of an
6139 atomic compare-and-swap operation within the SSA framework.
6140</p>
6141<h5>Examples:</h5>
6142
6143<pre>
6144%ptr = malloc i32
6145 store i32 4, %ptr
6146
6147%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6148%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6149 <i>; yields {i32}:result1 = 4</i>
6150%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6151%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6152
6153%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6154%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6155 <i>; yields {i32}:result2 = 8</i>
6156%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6157
6158%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6159</pre>
6160</div>
6161
6162<!-- _______________________________________________________________________ -->
6163<div class="doc_subsubsection">
6164 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6165</div>
6166<div class="doc_text">
6167<h5>Syntax:</h5>
6168
6169<p>
6170 This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6171 integer bit width. Not all targets support all bit widths however.</p>
6172<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6173declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6174declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6175declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6176declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6177
6178</pre>
6179<h5>Overview:</h5>
6180<p>
6181 This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6182 the value from memory. It then stores the value in <tt>val</tt> in the memory
6183 at <tt>ptr</tt>.
6184</p>
6185<h5>Arguments:</h5>
6186
6187<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6188 The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6189 <tt>val</tt> argument and the result must be integers of the same bit width.
6190 The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6191 integer type. The targets may only lower integer representations they
6192 support.
6193</p>
6194<h5>Semantics:</h5>
6195<p>
6196 This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6197 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6198 equivalent of an atomic swap operation within the SSA framework.
6199
6200</p>
6201<h5>Examples:</h5>
6202<pre>
6203%ptr = malloc i32
6204 store i32 4, %ptr
6205
6206%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6207%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6208 <i>; yields {i32}:result1 = 4</i>
6209%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6210%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6211
6212%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6213%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6214 <i>; yields {i32}:result2 = 8</i>
6215
6216%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6217%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6218</pre>
6219</div>
6220
6221<!-- _______________________________________________________________________ -->
6222<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6223 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6224
6225</div>
6226<div class="doc_text">
6227<h5>Syntax:</h5>
6228<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6229 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]6230 integer bit width. Not all targets support all bit widths however.</p>
6231<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6232declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6233declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6234declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6235declare 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]6236
6237</pre>
6238<h5>Overview:</h5>
6239<p>
6240 This intrinsic adds <tt>delta</tt> to the value stored in memory at
6241 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6242</p>
6243<h5>Arguments:</h5>
6244<p>
6245
6246 The intrinsic takes two arguments, the first a pointer to an integer value
6247 and the second an integer value. The result is also an integer value. These
6248 integer types can have any bit width, but they must all have the same bit
6249 width. The targets may only lower integer representations they support.
6250</p>
6251<h5>Semantics:</h5>
6252<p>
6253 This intrinsic does a series of operations atomically. It first loads the
6254 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6255 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6256</p>
6257
6258<h5>Examples:</h5>
6259<pre>
6260%ptr = malloc i32
6261 store i32 4, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6262%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6263 <i>; yields {i32}:result1 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6264%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6265 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6266%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6267 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6268%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6269</pre>
6270</div>
6271
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6272<!-- _______________________________________________________________________ -->
6273<div class="doc_subsubsection">
6274 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6275
6276</div>
6277<div class="doc_text">
6278<h5>Syntax:</h5>
6279<p>
6280 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]6281 any integer bit width and for different address spaces. Not all targets
6282 support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6283<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6284declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6285declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6286declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6287declare 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]6288
6289</pre>
6290<h5>Overview:</h5>
6291<p>
6292 This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6293 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6294</p>
6295<h5>Arguments:</h5>
6296<p>
6297
6298 The intrinsic takes two arguments, the first a pointer to an integer value
6299 and the second an integer value. The result is also an integer value. These
6300 integer types can have any bit width, but they must all have the same bit
6301 width. The targets may only lower integer representations they support.
6302</p>
6303<h5>Semantics:</h5>
6304<p>
6305 This intrinsic does a series of operations atomically. It first loads the
6306 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6307 result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6308</p>
6309
6310<h5>Examples:</h5>
6311<pre>
6312%ptr = malloc i32
6313 store i32 8, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6314%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6315 <i>; yields {i32}:result1 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6316%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6317 <i>; yields {i32}:result2 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6318%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6319 <i>; yields {i32}:result3 = 2</i>
6320%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6321</pre>
6322</div>
6323
6324<!-- _______________________________________________________________________ -->
6325<div class="doc_subsubsection">
6326 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6327 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6328 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6329 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
6330
6331</div>
6332<div class="doc_text">
6333<h5>Syntax:</h5>
6334<p>
6335 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
6336 <tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6337 <tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
6338 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6339<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6340declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6341declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6342declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6343declare 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]6344
6345</pre>
6346
6347<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6348declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6349declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6350declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6351declare 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]6352
6353</pre>
6354
6355<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6356declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6357declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6358declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6359declare 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]6360
6361</pre>
6362
6363<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6364declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6365declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6366declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6367declare 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]6368
6369</pre>
6370<h5>Overview:</h5>
6371<p>
6372 These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6373 the value stored in memory at <tt>ptr</tt>. It yields the original value
6374 at <tt>ptr</tt>.
6375</p>
6376<h5>Arguments:</h5>
6377<p>
6378
6379 These intrinsics take two arguments, the first a pointer to an integer value
6380 and the second an integer value. The result is also an integer value. These
6381 integer types can have any bit width, but they must all have the same bit
6382 width. The targets may only lower integer representations they support.
6383</p>
6384<h5>Semantics:</h5>
6385<p>
6386 These intrinsics does a series of operations atomically. They first load the
6387 value stored at <tt>ptr</tt>. They then do the bitwise operation
6388 <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
6389 value stored at <tt>ptr</tt>.
6390</p>
6391
6392<h5>Examples:</h5>
6393<pre>
6394%ptr = malloc i32
6395 store i32 0x0F0F, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6396%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6397 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6398%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6399 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6400%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6401 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6402%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6403 <i>; yields {i32}:result3 = FF</i>
6404%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6405</pre>
6406</div>
6407
6408
6409<!-- _______________________________________________________________________ -->
6410<div class="doc_subsubsection">
6411 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6412 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6413 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6414 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
6415
6416</div>
6417<div class="doc_text">
6418<h5>Syntax:</h5>
6419<p>
6420 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6421 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6422 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6423 address spaces. Not all targets
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6424 support all bit widths however.</p>
6425<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6426declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6427declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6428declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6429declare 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]6430
6431</pre>
6432
6433<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6434declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6435declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6436declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6437declare 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]6438
6439</pre>
6440
6441<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6442declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6443declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6444declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6445declare 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]6446
6447</pre>
6448
6449<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6450declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6451declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6452declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6453declare 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]6454
6455</pre>
6456<h5>Overview:</h5>
6457<p>
6458 These intrinsics takes the signed or unsigned minimum or maximum of
6459 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6460 original value at <tt>ptr</tt>.
6461</p>
6462<h5>Arguments:</h5>
6463<p>
6464
6465 These intrinsics take two arguments, the first a pointer to an integer value
6466 and the second an integer value. The result is also an integer value. These
6467 integer types can have any bit width, but they must all have the same bit
6468 width. The targets may only lower integer representations they support.
6469</p>
6470<h5>Semantics:</h5>
6471<p>
6472 These intrinsics does a series of operations atomically. They first load the
6473 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
6474 <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
6475 the original value stored at <tt>ptr</tt>.
6476</p>
6477
6478<h5>Examples:</h5>
6479<pre>
6480%ptr = malloc i32
6481 store i32 7, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6482%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6483 <i>; yields {i32}:result0 = 7</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6484%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6485 <i>; yields {i32}:result1 = -2</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6486%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6487 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6488%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6489 <i>; yields {i32}:result3 = 8</i>
6490%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6491</pre>
6492</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6493
6494<!-- ======================================================================= -->
6495<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6496 <a name="int_general">General Intrinsics</a>
6497</div>
6498
6499<div class="doc_text">
6500<p> This class of intrinsics is designed to be generic and has
6501no specific purpose. </p>
6502</div>
6503
6504<!-- _______________________________________________________________________ -->
6505<div class="doc_subsubsection">
6506 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6507</div>
6508
6509<div class="doc_text">
6510
6511<h5>Syntax:</h5>
6512<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]6513 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]6514</pre>
6515
6516<h5>Overview:</h5>
6517
6518<p>
6519The '<tt>llvm.var.annotation</tt>' intrinsic
6520</p>
6521
6522<h5>Arguments:</h5>
6523
6524<p>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]6525The first argument is a pointer to a value, the second is a pointer to a
6526global string, the third is a pointer to a global string which is the source
6527file name, and the last argument is the line number.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6528</p>
6529
6530<h5>Semantics:</h5>
6531
6532<p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6533This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6534This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6535annotations. These have no other defined use, they are ignored by code
6536generation and optimization.
6537</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6538</div>
6539
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6540<!-- _______________________________________________________________________ -->
6541<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]6542 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6543</div>
6544
6545<div class="doc_text">
6546
6547<h5>Syntax:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6548<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6549any integer bit width.
6550</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6551<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]6552 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6553 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6554 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6555 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6556 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]6557</pre>
6558
6559<h5>Overview:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6560
6561<p>
6562The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6563</p>
6564
6565<h5>Arguments:</h5>
6566
6567<p>
6568The first argument is an integer value (result of some expression),
6569the second is a pointer to a global string, the third is a pointer to a global
6570string which is the source file name, and the last argument is the line number.
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6571It returns the value of the first argument.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6572</p>
6573
6574<h5>Semantics:</h5>
6575
6576<p>
6577This intrinsic allows annotations to be put on arbitrary expressions
6578with arbitrary strings. This can be useful for special purpose optimizations
6579that want to look for these annotations. These have no other defined use, they
6580are ignored by code generation and optimization.
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6581</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6582</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6583
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6584<!-- _______________________________________________________________________ -->
6585<div class="doc_subsubsection">
6586 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6587</div>
6588
6589<div class="doc_text">
6590
6591<h5>Syntax:</h5>
6592<pre>
6593 declare void @llvm.trap()
6594</pre>
6595
6596<h5>Overview:</h5>
6597
6598<p>
6599The '<tt>llvm.trap</tt>' intrinsic
6600</p>
6601
6602<h5>Arguments:</h5>
6603
6604<p>
6605None
6606</p>
6607
6608<h5>Semantics:</h5>
6609
6610<p>
6611This intrinsics is lowered to the target dependent trap instruction. If the
6612target does not have a trap instruction, this intrinsic will be lowered to the
6613call of the abort() function.
6614</p>
6615</div>
6616
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6617<!-- _______________________________________________________________________ -->
6618<div class="doc_subsubsection">
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]6619 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6620</div>
6621<div class="doc_text">
6622<h5>Syntax:</h5>
6623<pre>
6624declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
6625
6626</pre>
6627<h5>Overview:</h5>
6628<p>
6629 The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
6630 it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
6631 it is placed on the stack before local variables.
6632</p>
6633<h5>Arguments:</h5>
6634<p>
6635 The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
6636 first argument is the value loaded from the stack guard
6637 <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
6638 has enough space to hold the value of the guard.
6639</p>
6640<h5>Semantics:</h5>
6641<p>
6642 This intrinsic causes the prologue/epilogue inserter to force the position of
6643 the <tt>AllocaInst</tt> stack slot to be before local variables on the
6644 stack. This is to ensure that if a local variable on the stack is overwritten,
6645 it will destroy the value of the guard. When the function exits, the guard on
6646 the stack is checked against the original guard. If they're different, then
6647 the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
6648</p>
6649</div>
6650
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6651<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6652<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6653<address>
6654 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]6655 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6656 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]6657 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]6658
6659 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]6660 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6661 Last modified: $Date$
6662</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]6663
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6664</body>
6665</html>