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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 41b485c9c35b90bb7ee55dca2d5375980e546039 / . / docs / LangRef.html
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4<head>
5 <title>LLVM Assembly Language Reference Manual</title>
Reid Spencer3921c742004-08-26 20:44:00 +0000[diff] [blame]6 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
7 <meta name="author" content="Chris Lattner">
8 <meta name="description"
9 content="LLVM Assembly Language Reference Manual.">
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]10 <link rel="stylesheet" href="llvm.css" type="text/css">
11</head>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]14
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]15<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]16<ol>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]17 <li><a href="#abstract">Abstract</a></li>
18 <li><a href="#introduction">Introduction</a></li>
19 <li><a href="#identifiers">Identifiers</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]20 <li><a href="#highlevel">High Level Structure</a>
21 <ol>
22 <li><a href="#modulestructure">Module Structure</a></li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a></li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]24 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]25 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]26 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]27 <li><a href="#functionstructure">Functions</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]28 <li><a href="#aliasstructure">Aliases</a></li>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]29 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]30 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]31 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]32 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]33 <li><a href="#datalayout">Data Layout</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]34 </ol>
35 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]36 <li><a href="#typesystem">Type System</a>
37 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]38 <li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]39 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]40 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]41 <li><a href="#t_floating">Floating Point Types</a></li>
42 <li><a href="#t_void">Void Type</a></li>
43 <li><a href="#t_label">Label Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]44 </ol>
45 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]46 <li><a href="#t_derived">Derived Types</a>
47 <ol>
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]48 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]49 <li><a href="#t_array">Array Type</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]50 <li><a href="#t_function">Function Type</a></li>
51 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]52 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]53 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]54 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]55 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]56 </ol>
57 </li>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]58 <li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]59 </ol>
60 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]61 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]62 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]63 <li><a href="#simpleconstants">Simple Constants</a></li>
64 <li><a href="#aggregateconstants">Aggregate Constants</a></li>
65 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
66 <li><a href="#undefvalues">Undefined Values</a></li>
67 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]68 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]69 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]70 <li><a href="#othervalues">Other Values</a>
71 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]72 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]73 </ol>
74 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]75 <li><a href="#instref">Instruction Reference</a>
76 <ol>
77 <li><a href="#terminators">Terminator Instructions</a>
78 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]79 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
80 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]81 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
82 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]83 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]84 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]85 </ol>
86 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]87 <li><a href="#binaryops">Binary Operations</a>
88 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]89 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
90 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
91 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]92 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
93 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
94 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]95 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
96 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
97 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]98 </ol>
99 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]100 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
101 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]102 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
103 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
104 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]105 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]106 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]107 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]108 </ol>
109 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]110 <li><a href="#vectorops">Vector Operations</a>
111 <ol>
112 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
113 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
114 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]115 </ol>
116 </li>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]117 <li><a href="#aggregateops">Aggregate Operations</a>
118 <ol>
119 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
120 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
121 </ol>
122 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]123 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]124 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]125 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
126 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
127 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]128 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
129 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
130 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]131 </ol>
132 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]133 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]134 <ol>
135 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
136 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
137 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
138 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
139 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]140 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
141 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
142 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
143 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]144 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
145 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]146 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]147 </ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]148 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]149 <li><a href="#otherops">Other Operations</a>
150 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]151 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
152 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]153 <li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
154 <li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]155 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]156 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]157 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]158 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]159 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]160 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]161 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]162 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]163 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]164 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]165 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
166 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]167 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
168 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
169 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]170 </ol>
171 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]172 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
173 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]174 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
175 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
176 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]177 </ol>
178 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]179 <li><a href="#int_codegen">Code Generator Intrinsics</a>
180 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]181 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
182 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
183 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
184 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
185 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
186 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
187 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]188 </ol>
189 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]190 <li><a href="#int_libc">Standard C Library Intrinsics</a>
191 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]192 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
193 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
194 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
195 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
196 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]197 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
198 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
199 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]200 </ol>
201 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]202 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]203 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]204 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]205 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
206 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
207 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]208 <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
209 <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]210 </ol>
211 </li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]212 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
213 <ol>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]214 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
215 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
216 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
217 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
218 <li><a href="#int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame^]219 <li><a href="#int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]220 </ol>
221 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]222 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]223 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]224 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]225 <ol>
226 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]227 </ol>
228 </li>
Bill Wendling3c44f5b2008-11-18 22:10:53 +0000[diff] [blame]229 <li><a href="#int_atomics">Atomic intrinsics</a>
230 <ol>
231 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
232 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
233 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
234 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
235 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
236 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
237 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
238 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
239 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
240 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
241 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
242 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
243 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
244 </ol>
245 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]246 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]247 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]248 <li><a href="#int_var_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]249 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]250 <li><a href="#int_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]251 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]252 <li><a href="#int_trap">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]253 '<tt>llvm.trap</tt>' Intrinsic</a></li>
254 <li><a href="#int_stackprotector">
255 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]256 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]257 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]258 </ol>
259 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]260</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]261
262<div class="doc_author">
263 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
264 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]265</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]266
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]267<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]268<div class="doc_section"> <a name="abstract">Abstract </a></div>
269<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]270
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]271<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]272<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling837f39b2008-08-05 22:29:16 +0000[diff] [blame]273LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]274type safety, low-level operations, flexibility, and the capability of
275representing 'all' high-level languages cleanly. It is the common code
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]276representation used throughout all phases of the LLVM compilation
277strategy.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]278</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]279
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]280<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]281<div class="doc_section"> <a name="introduction">Introduction</a> </div>
282<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]283
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]284<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]285
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]286<p>The LLVM code representation is designed to be used in three
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]287different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]288representation (suitable for fast loading by a Just-In-Time compiler),
289and as a human readable assembly language representation. This allows
290LLVM to provide a powerful intermediate representation for efficient
291compiler transformations and analysis, while providing a natural means
292to debug and visualize the transformations. The three different forms
293of LLVM are all equivalent. This document describes the human readable
294representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]295
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]296<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]297while being expressive, typed, and extensible at the same time. It
298aims to be a "universal IR" of sorts, by being at a low enough level
299that high-level ideas may be cleanly mapped to it (similar to how
300microprocessors are "universal IR's", allowing many source languages to
301be mapped to them). By providing type information, LLVM can be used as
302the target of optimizations: for example, through pointer analysis, it
303can be proven that a C automatic variable is never accessed outside of
304the current function... allowing it to be promoted to a simple SSA
305value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]306
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]307</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]308
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]309<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]310<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]311
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]312<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]313
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]314<p>It is important to note that this document describes 'well formed'
315LLVM assembly language. There is a difference between what the parser
316accepts and what is considered 'well formed'. For example, the
317following instruction is syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]318
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]319<div class="doc_code">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]320<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]321%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]322</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]323</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]324
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]325<p>...because the definition of <tt>%x</tt> does not dominate all of
326its uses. The LLVM infrastructure provides a verification pass that may
327be used to verify that an LLVM module is well formed. This pass is
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]328automatically run by the parser after parsing input assembly and by
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]329the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]330by the verifier pass indicate bugs in transformation passes or input to
331the parser.</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]332</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]333
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]334<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]335
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]336<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]337<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]338<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]339
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]340<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]341
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]342 <p>LLVM identifiers come in two basic types: global and local. Global
343 identifiers (functions, global variables) begin with the @ character. Local
344 identifiers (register names, types) begin with the % character. Additionally,
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]345 there are three different formats for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]346
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]347<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]348 <li>Named values are represented as a string of characters with their prefix.
349 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
350 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]351 Identifiers which require other characters in their names can be surrounded
Daniel Dunbar76dea952008-10-14 23:51:43 +0000[diff] [blame]352 with quotes. Special characters may be escaped using "\xx" where xx is the
353 ASCII code for the character in hexadecimal. In this way, any character can
354 be used in a name value, even quotes themselves.
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]355
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]356 <li>Unnamed values are represented as an unsigned numeric value with their
357 prefix. For example, %12, @2, %44.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]358
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]359 <li>Constants, which are described in a <a href="#constants">section about
360 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]361</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]362
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]363<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]364don't need to worry about name clashes with reserved words, and the set of
365reserved words may be expanded in the future without penalty. Additionally,
366unnamed identifiers allow a compiler to quickly come up with a temporary
367variable without having to avoid symbol table conflicts.</p>
368
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]369<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]370languages. There are keywords for different opcodes
371('<tt><a href="#i_add">add</a></tt>',
372 '<tt><a href="#i_bitcast">bitcast</a></tt>',
373 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names ('<tt><a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]374href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]375and others. These reserved words cannot conflict with variable names, because
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]376none of them start with a prefix character ('%' or '@').</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]377
378<p>Here is an example of LLVM code to multiply the integer variable
379'<tt>%X</tt>' by 8:</p>
380
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]381<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]382
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]383<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]384<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]385%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]386</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]387</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]388
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]389<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]390
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]391<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]392<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]393%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]394</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]395</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]396
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]397<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]398
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]399<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]400<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]401<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
402<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
403%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]404</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]405</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]406
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]407<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
408important lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]409
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]410<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]411
412 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
413 line.</li>
414
415 <li>Unnamed temporaries are created when the result of a computation is not
416 assigned to a named value.</li>
417
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]418 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]419
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]420</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]421
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]422<p>...and it also shows a convention that we follow in this document. When
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]423demonstrating instructions, we will follow an instruction with a comment that
424defines the type and name of value produced. Comments are shown in italic
425text.</p>
426
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]427</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]428
429<!-- *********************************************************************** -->
430<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
431<!-- *********************************************************************** -->
432
433<!-- ======================================================================= -->
434<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
435</div>
436
437<div class="doc_text">
438
439<p>LLVM programs are composed of "Module"s, each of which is a
440translation unit of the input programs. Each module consists of
441functions, global variables, and symbol table entries. Modules may be
442combined together with the LLVM linker, which merges function (and
443global variable) definitions, resolves forward declarations, and merges
444symbol table entries. Here is an example of the "hello world" module:</p>
445
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]446<div class="doc_code">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]447<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]448<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
449 href="#globalvars">constant</a> <a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]450
451<i>; External declaration of the puts function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]452<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]453
454<i>; Definition of main function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]455define i32 @main() { <i>; i32()* </i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]456 <i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]457 %cast210 = <a
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]458 href="#i_getelementptr">getelementptr</a> [13 x i8]* @.LC0, i64 0, i64 0 <i>; i8 *</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]459
460 <i>; Call puts function to write out the string to stdout...</i>
461 <a
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]462 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]463 <a
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]464 href="#i_ret">ret</a> i32 0<br>}<br>
465</pre>
466</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]467
468<p>This example is made up of a <a href="#globalvars">global variable</a>
469named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
470function, and a <a href="#functionstructure">function definition</a>
471for "<tt>main</tt>".</p>
472
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]473<p>In general, a module is made up of a list of global values,
474where both functions and global variables are global values. Global values are
475represented by a pointer to a memory location (in this case, a pointer to an
476array of char, and a pointer to a function), and have one of the following <a
477href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]478
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]479</div>
480
481<!-- ======================================================================= -->
482<div class="doc_subsection">
483 <a name="linkage">Linkage Types</a>
484</div>
485
486<div class="doc_text">
487
488<p>
489All Global Variables and Functions have one of the following types of linkage:
490</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]491
492<dl>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]493
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]494 <dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
495
496 <dd>Global values with private linkage are only directly accessible by
497 objects in the current module. In particular, linking code into a module with
498 an private global value may cause the private to be renamed as necessary to
499 avoid collisions. Because the symbol is private to the module, all
500 references can be updated. This doesn't show up in any symbol table in the
501 object file.
502 </dd>
503
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]504 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]505
Duncan Sands81d05c22009-01-16 09:29:46 +0000[diff] [blame]506 <dd> Similar to private, but the value shows as a local symbol (STB_LOCAL in
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]507 the case of ELF) in the object file. This corresponds to the notion of the
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]508 '<tt>static</tt>' keyword in C.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]509 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]510
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]511 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]512
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]513 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
514 the same name when linkage occurs. This is typically used to implement
515 inline functions, templates, or other code which must be generated in each
516 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
517 allowed to be discarded.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]518 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]519
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]520 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
521
522 <dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
523 linkage, except that unreferenced <tt>common</tt> globals may not be
524 discarded. This is used for globals that may be emitted in multiple
525 translation units, but that are not guaranteed to be emitted into every
526 translation unit that uses them. One example of this is tentative
527 definitions in C, such as "<tt>int X;</tt>" at global scope.
528 </dd>
529
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]530 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]531
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]532 <dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
533 that some targets may choose to emit different assembly sequences for them
534 for target-dependent reasons. This is used for globals that are declared
535 "weak" in C source code.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]536 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]537
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]538 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]539
540 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
541 pointer to array type. When two global variables with appending linkage are
542 linked together, the two global arrays are appended together. This is the
543 LLVM, typesafe, equivalent of having the system linker append together
544 "sections" with identical names when .o files are linked.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]545 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]546
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]547 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]548 <dd>The semantics of this linkage follow the ELF object file model: the
549 symbol is weak until linked, if not linked, the symbol becomes null instead
550 of being an undefined reference.
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]551 </dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]552
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]553 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]554
555 <dd>If none of the above identifiers are used, the global is externally
556 visible, meaning that it participates in linkage and can be used to resolve
557 external symbol references.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]558 </dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]559</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]560
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]561 <p>
562 The next two types of linkage are targeted for Microsoft Windows platform
563 only. They are designed to support importing (exporting) symbols from (to)
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]564 DLLs (Dynamic Link Libraries).
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]565 </p>
566
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]567 <dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]568 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
569
570 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
571 or variable via a global pointer to a pointer that is set up by the DLL
572 exporting the symbol. On Microsoft Windows targets, the pointer name is
Dan Gohman79564122009-01-12 21:35:55 +0000[diff] [blame]573 formed by combining <code>__imp_</code> and the function or variable name.
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]574 </dd>
575
576 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
577
578 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
579 pointer to a pointer in a DLL, so that it can be referenced with the
580 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
Dan Gohman79564122009-01-12 21:35:55 +0000[diff] [blame]581 name is formed by combining <code>__imp_</code> and the function or variable
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]582 name.
583 </dd>
584
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]585</dl>
586
Dan Gohmanf0032762008-11-24 17:18:39 +0000[diff] [blame]587<p>For example, since the "<tt>.LC0</tt>"
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]588variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
589variable and was linked with this one, one of the two would be renamed,
590preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
591external (i.e., lacking any linkage declarations), they are accessible
Reid Spencerac8d2762007-01-05 00:59:10 +0000[diff] [blame]592outside of the current module.</p>
593<p>It is illegal for a function <i>declaration</i>
594to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]595or <tt>extern_weak</tt>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]596<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]597linkages.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]598</div>
599
600<!-- ======================================================================= -->
601<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]602 <a name="callingconv">Calling Conventions</a>
603</div>
604
605<div class="doc_text">
606
607<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
608and <a href="#i_invoke">invokes</a> can all have an optional calling convention
609specified for the call. The calling convention of any pair of dynamic
610caller/callee must match, or the behavior of the program is undefined. The
611following calling conventions are supported by LLVM, and more may be added in
612the future:</p>
613
614<dl>
615 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
616
617 <dd>This calling convention (the default if no other calling convention is
618 specified) matches the target C calling conventions. This calling convention
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]619 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencerc28d2bc2006-12-31 21:30:18 +0000[diff] [blame]620 prototype and implemented declaration of the function (as does normal C).
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]621 </dd>
622
623 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
624
625 <dd>This calling convention attempts to make calls as fast as possible
626 (e.g. by passing things in registers). This calling convention allows the
627 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]628 without having to conform to an externally specified ABI (Application Binary
629 Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer9097d142008-05-14 09:17:12 +0000[diff] [blame]630 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
631 supported. This calling convention does not support varargs and requires the
632 prototype of all callees to exactly match the prototype of the function
633 definition.
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]634 </dd>
635
636 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
637
638 <dd>This calling convention attempts to make code in the caller as efficient
639 as possible under the assumption that the call is not commonly executed. As
640 such, these calls often preserve all registers so that the call does not break
641 any live ranges in the caller side. This calling convention does not support
642 varargs and requires the prototype of all callees to exactly match the
643 prototype of the function definition.
644 </dd>
645
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]646 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]647
648 <dd>Any calling convention may be specified by number, allowing
649 target-specific calling conventions to be used. Target specific calling
650 conventions start at 64.
651 </dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]652</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]653
654<p>More calling conventions can be added/defined on an as-needed basis, to
655support pascal conventions or any other well-known target-independent
656convention.</p>
657
658</div>
659
660<!-- ======================================================================= -->
661<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]662 <a name="visibility">Visibility Styles</a>
663</div>
664
665<div class="doc_text">
666
667<p>
668All Global Variables and Functions have one of the following visibility styles:
669</p>
670
671<dl>
672 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
673
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]674 <dd>On targets that use the ELF object file format, default visibility means
675 that the declaration is visible to other
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]676 modules and, in shared libraries, means that the declared entity may be
677 overridden. On Darwin, default visibility means that the declaration is
678 visible to other modules. Default visibility corresponds to "external
679 linkage" in the language.
680 </dd>
681
682 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
683
684 <dd>Two declarations of an object with hidden visibility refer to the same
685 object if they are in the same shared object. Usually, hidden visibility
686 indicates that the symbol will not be placed into the dynamic symbol table,
687 so no other module (executable or shared library) can reference it
688 directly.
689 </dd>
690
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]691 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
692
693 <dd>On ELF, protected visibility indicates that the symbol will be placed in
694 the dynamic symbol table, but that references within the defining module will
695 bind to the local symbol. That is, the symbol cannot be overridden by another
696 module.
697 </dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]698</dl>
699
700</div>
701
702<!-- ======================================================================= -->
703<div class="doc_subsection">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]704 <a name="namedtypes">Named Types</a>
705</div>
706
707<div class="doc_text">
708
709<p>LLVM IR allows you to specify name aliases for certain types. This can make
710it easier to read the IR and make the IR more condensed (particularly when
711recursive types are involved). An example of a name specification is:
712</p>
713
714<div class="doc_code">
715<pre>
716%mytype = type { %mytype*, i32 }
717</pre>
718</div>
719
720<p>You may give a name to any <a href="#typesystem">type</a> except "<a
721href="t_void">void</a>". Type name aliases may be used anywhere a type is
722expected with the syntax "%mytype".</p>
723
724<p>Note that type names are aliases for the structural type that they indicate,
725and that you can therefore specify multiple names for the same type. This often
726leads to confusing behavior when dumping out a .ll file. Since LLVM IR uses
727structural typing, the name is not part of the type. When printing out LLVM IR,
728the printer will pick <em>one name</em> to render all types of a particular
729shape. This means that if you have code where two different source types end up
730having the same LLVM type, that the dumper will sometimes print the "wrong" or
731unexpected type. This is an important design point and isn't going to
732change.</p>
733
734</div>
735
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]736<!-- ======================================================================= -->
737<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]738 <a name="globalvars">Global Variables</a>
739</div>
740
741<div class="doc_text">
742
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]743<p>Global variables define regions of memory allocated at compilation time
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]744instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]745an explicit section to be placed in, and may have an optional explicit alignment
746specified. A variable may be defined as "thread_local", which means that it
747will not be shared by threads (each thread will have a separated copy of the
748variable). A variable may be defined as a global "constant," which indicates
749that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]750optimization, allowing the global data to be placed in the read-only section of
751an executable, etc). Note that variables that need runtime initialization
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]752cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]753
754<p>
755LLVM explicitly allows <em>declarations</em> of global variables to be marked
756constant, even if the final definition of the global is not. This capability
757can be used to enable slightly better optimization of the program, but requires
758the language definition to guarantee that optimizations based on the
759'constantness' are valid for the translation units that do not include the
760definition.
761</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]762
763<p>As SSA values, global variables define pointer values that are in
764scope (i.e. they dominate) all basic blocks in the program. Global
765variables always define a pointer to their "content" type because they
766describe a region of memory, and all memory objects in LLVM are
767accessed through pointers.</p>
768
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]769<p>A global variable may be declared to reside in a target-specifc numbered
770address space. For targets that support them, address spaces may affect how
771optimizations are performed and/or what target instructions are used to access
Christopher Lambd49e18d2007-12-12 08:44:39 +0000[diff] [blame]772the variable. The default address space is zero. The address space qualifier
773must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]774
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]775<p>LLVM allows an explicit section to be specified for globals. If the target
776supports it, it will emit globals to the section specified.</p>
777
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]778<p>An explicit alignment may be specified for a global. If not present, or if
779the alignment is set to zero, the alignment of the global is set by the target
780to whatever it feels convenient. If an explicit alignment is specified, the
781global is forced to have at least that much alignment. All alignments must be
782a power of 2.</p>
783
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]784<p>For example, the following defines a global in a numbered address space with
785an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]786
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]787<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]788<pre>
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]789@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]790</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]791</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]792
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]793</div>
794
795
796<!-- ======================================================================= -->
797<div class="doc_subsection">
798 <a name="functionstructure">Functions</a>
799</div>
800
801<div class="doc_text">
802
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]803<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
804an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]805<a href="#visibility">visibility style</a>, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]806<a href="#callingconv">calling convention</a>, a return type, an optional
807<a href="#paramattrs">parameter attribute</a> for the return type, a function
808name, a (possibly empty) argument list (each with optional
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]809<a href="#paramattrs">parameter attributes</a>), optional
810<a href="#fnattrs">function attributes</a>, an optional section,
811an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner0c46a7d2008-10-04 18:10:21 +0000[diff] [blame]812an opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]813
814LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
815optional <a href="#linkage">linkage type</a>, an optional
816<a href="#visibility">visibility style</a>, an optional
817<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]818<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]819name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksene754abe2007-12-10 03:30:21 +0000[diff] [blame]820<a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]821
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]822<p>A function definition contains a list of basic blocks, forming the CFG
823(Control Flow Graph) for
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]824the function. Each basic block may optionally start with a label (giving the
825basic block a symbol table entry), contains a list of instructions, and ends
826with a <a href="#terminators">terminator</a> instruction (such as a branch or
827function return).</p>
828
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]829<p>The first basic block in a function is special in two ways: it is immediately
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]830executed on entrance to the function, and it is not allowed to have predecessor
831basic blocks (i.e. there can not be any branches to the entry block of a
832function). Because the block can have no predecessors, it also cannot have any
833<a href="#i_phi">PHI nodes</a>.</p>
834
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]835<p>LLVM allows an explicit section to be specified for functions. If the target
836supports it, it will emit functions to the section specified.</p>
837
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]838<p>An explicit alignment may be specified for a function. If not present, or if
839the alignment is set to zero, the alignment of the function is set by the target
840to whatever it feels convenient. If an explicit alignment is specified, the
841function is forced to have at least that much alignment. All alignments must be
842a power of 2.</p>
843
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]844 <h5>Syntax:</h5>
845
846<div class="doc_code">
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]847<tt>
848define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
849 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
850 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
851 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
852 [<a href="#gc">gc</a>] { ... }
853</tt>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]854</div>
855
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]856</div>
857
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]858
859<!-- ======================================================================= -->
860<div class="doc_subsection">
861 <a name="aliasstructure">Aliases</a>
862</div>
863<div class="doc_text">
864 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov726d45c2008-03-22 08:36:14 +0000[diff] [blame]865 function, global variable, another alias or bitcast of global value). Aliases
866 may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]867 optional <a href="#visibility">visibility style</a>.</p>
868
869 <h5>Syntax:</h5>
870
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]871<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]872<pre>
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]873@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]874</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]875</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]876
877</div>
878
879
880
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]881<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]882<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
883<div class="doc_text">
884 <p>The return type and each parameter of a function type may have a set of
885 <i>parameter attributes</i> associated with them. Parameter attributes are
886 used to communicate additional information about the result or parameters of
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]887 a function. Parameter attributes are considered to be part of the function,
888 not of the function type, so functions with different parameter attributes
889 can have the same function type.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]890
Reid Spencer950e9f82007-01-15 18:27:39 +0000[diff] [blame]891 <p>Parameter attributes are simple keywords that follow the type specified. If
892 multiple parameter attributes are needed, they are space separated. For
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]893 example:</p>
894
895<div class="doc_code">
896<pre>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]897declare i32 @printf(i8* noalias , ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]898declare i32 @atoi(i8 zeroext)
899declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]900</pre>
901</div>
902
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]903 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
904 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]905
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]906 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]907 <dl>
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]908 <dt><tt>zeroext</tt></dt>
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]909 <dd>This indicates to the code generator that the parameter or return value
910 should be zero-extended to a 32-bit value by the caller (for a parameter)
911 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]912
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]913 <dt><tt>signext</tt></dt>
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]914 <dd>This indicates to the code generator that the parameter or return value
915 should be sign-extended to a 32-bit value by the caller (for a parameter)
916 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]917
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]918 <dt><tt>inreg</tt></dt>
Dale Johannesenc9c6da62008-09-25 20:47:45 +0000[diff] [blame]919 <dd>This indicates that this parameter or return value should be treated
920 in a special target-dependent fashion during while emitting code for a
921 function call or return (usually, by putting it in a register as opposed
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]922 to memory, though some targets use it to distinguish between two different
923 kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]924
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]925 <dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner0747baa2008-01-15 04:34:22 +0000[diff] [blame]926 <dd>This indicates that the pointer parameter should really be passed by
927 value to the function. The attribute implies that a hidden copy of the
928 pointee is made between the caller and the callee, so the callee is unable
Chris Lattnerebec6782008-08-05 18:21:08 +0000[diff] [blame]929 to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner0747baa2008-01-15 04:34:22 +0000[diff] [blame]930 pointer arguments. It is generally used to pass structs and arrays by
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]931 value, but is also valid on pointers to scalars. The copy is considered to
932 belong to the caller not the callee (for example,
933 <tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]934 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattnerce459b12009-02-05 05:42:28 +0000[diff] [blame]935 values. The byval attribute also supports specifying an alignment with the
936 align attribute. This has a target-specific effect on the code generator
937 that usually indicates a desired alignment for the synthesized stack
938 slot.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]939
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]940 <dt><tt>sret</tt></dt>
Duncan Sandse26dec62008-02-18 04:19:38 +0000[diff] [blame]941 <dd>This indicates that the pointer parameter specifies the address of a
942 structure that is the return value of the function in the source program.
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]943 This pointer must be guaranteed by the caller to be valid: loads and stores
944 to the structure may be assumed by the callee to not to trap. This may only
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]945 be applied to the first parameter. This is not a valid attribute for
946 return values. </dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]947
Zhou Shengfebca342007-06-05 05:28:26 +0000[diff] [blame]948 <dt><tt>noalias</tt></dt>
Nick Lewycky02ff3082008-11-24 03:41:24 +0000[diff] [blame]949 <dd>This indicates that the pointer does not alias any global or any other
950 parameter. The caller is responsible for ensuring that this is the
Nick Lewyckyb2b32fd2008-11-24 05:00:44 +0000[diff] [blame]951 case. On a function return value, <tt>noalias</tt> additionally indicates
952 that the pointer does not alias any other pointers visible to the
Nick Lewyckyf23d0d32008-12-19 06:39:12 +0000[diff] [blame]953 caller. For further details, please see the discussion of the NoAlias
954 response in
955 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
956 analysis</a>.</dd>
957
958 <dt><tt>nocapture</tt></dt>
959 <dd>This indicates that the callee does not make any copies of the pointer
960 that outlive the callee itself. This is not a valid attribute for return
961 values.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]962
Duncan Sands50f19f52007-07-27 19:57:41 +0000[diff] [blame]963 <dt><tt>nest</tt></dt>
Duncan Sands0789b8b2008-07-08 09:27:25 +0000[diff] [blame]964 <dd>This indicates that the pointer parameter can be excised using the
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]965 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
966 attribute for return values.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]967 </dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]968
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]969</div>
970
971<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]972<div class="doc_subsection">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]973 <a name="gc">Garbage Collector Names</a>
974</div>
975
976<div class="doc_text">
977<p>Each function may specify a garbage collector name, which is simply a
978string.</p>
979
980<div class="doc_code"><pre
981>define void @f() gc "name" { ...</pre></div>
982
983<p>The compiler declares the supported values of <i>name</i>. Specifying a
984collector which will cause the compiler to alter its output in order to support
985the named garbage collection algorithm.</p>
986</div>
987
988<!-- ======================================================================= -->
989<div class="doc_subsection">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]990 <a name="fnattrs">Function Attributes</a>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]991</div>
992
993<div class="doc_text">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]994
995<p>Function attributes are set to communicate additional information about
996 a function. Function attributes are considered to be part of the function,
997 not of the function type, so functions with different parameter attributes
998 can have the same function type.</p>
999
1000 <p>Function attributes are simple keywords that follow the type specified. If
1001 multiple attributes are needed, they are space separated. For
1002 example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1003
1004<div class="doc_code">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1005<pre>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1006define void @f() noinline { ... }
1007define void @f() alwaysinline { ... }
1008define void @f() alwaysinline optsize { ... }
1009define void @f() optsize
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1010</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1011</div>
1012
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1013<dl>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1014<dt><tt>alwaysinline</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1015<dd>This attribute indicates that the inliner should attempt to inline this
1016function into callers whenever possible, ignoring any active inlining size
1017threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1018
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1019<dt><tt>noinline</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1020<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner94b5f7d2008-10-05 17:14:59 +0000[diff] [blame]1021in any situation. This attribute may not be used together with the
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1022<tt>alwaysinline</tt> attribute.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1023
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1024<dt><tt>optsize</tt></dt>
Devang Patel66c6c652008-09-29 18:34:44 +0000[diff] [blame]1025<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1026make choices that keep the code size of this function low, and otherwise do
1027optimizations specifically to reduce code size.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1028
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1029<dt><tt>noreturn</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1030<dd>This function attribute indicates that the function never returns normally.
1031This produces undefined behavior at runtime if the function ever does
1032dynamically return.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1033
1034<dt><tt>nounwind</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1035<dd>This function attribute indicates that the function never returns with an
1036unwind or exceptional control flow. If the function does unwind, its runtime
1037behavior is undefined.</dd>
1038
1039<dt><tt>readnone</tt></dt>
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]1040<dd>This attribute indicates that the function computes its result (or the
1041exception it throws) based strictly on its arguments, without dereferencing any
1042pointer arguments or otherwise accessing any mutable state (e.g. memory, control
1043registers, etc) visible to caller functions. It does not write through any
1044pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
1045never changes any state visible to callers.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1046
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]1047<dt><tt><a name="readonly">readonly</a></tt></dt>
1048<dd>This attribute indicates that the function does not write through any
1049pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
1050or otherwise modify any state (e.g. memory, control registers, etc) visible to
1051caller functions. It may dereference pointer arguments and read state that may
1052be set in the caller. A readonly function always returns the same value (or
1053throws the same exception) when called with the same set of arguments and global
1054state.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1055
1056<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1057<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1058protector. It is in the form of a "canary"&mdash;a random value placed on the
1059stack before the local variables that's checked upon return from the function to
1060see if it has been overwritten. A heuristic is used to determine if a function
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1061needs stack protectors or not.
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1062
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1063<p>If a function that has an <tt>ssp</tt> attribute is inlined into a function
1064that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
1065have an <tt>ssp</tt> attribute.</p></dd>
1066
1067<dt><tt>sspreq</tt></dt>
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1068<dd>This attribute indicates that the function should <em>always</em> emit a
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1069stack smashing protector. This overrides the <tt><a href="#ssp">ssp</a></tt>
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1070function attribute.
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1071
1072<p>If a function that has an <tt>sspreq</tt> attribute is inlined into a
1073function that doesn't have an <tt>sspreq</tt> attribute or which has
1074an <tt>ssp</tt> attribute, then the resulting function will have
1075an <tt>sspreq</tt> attribute.</p></dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1076</dl>
1077
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1078</div>
1079
1080<!-- ======================================================================= -->
1081<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1082 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1083</div>
1084
1085<div class="doc_text">
1086<p>
1087Modules may contain "module-level inline asm" blocks, which corresponds to the
1088GCC "file scope inline asm" blocks. These blocks are internally concatenated by
1089LLVM and treated as a single unit, but may be separated in the .ll file if
1090desired. The syntax is very simple:
1091</p>
1092
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1093<div class="doc_code">
1094<pre>
1095module asm "inline asm code goes here"
1096module asm "more can go here"
1097</pre>
1098</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1099
1100<p>The strings can contain any character by escaping non-printable characters.
1101 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
1102 for the number.
1103</p>
1104
1105<p>
1106 The inline asm code is simply printed to the machine code .s file when
1107 assembly code is generated.
1108</p>
1109</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1110
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1111<!-- ======================================================================= -->
1112<div class="doc_subsection">
1113 <a name="datalayout">Data Layout</a>
1114</div>
1115
1116<div class="doc_text">
1117<p>A module may specify a target specific data layout string that specifies how
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]1118data is to be laid out in memory. The syntax for the data layout is simply:</p>
1119<pre> target datalayout = "<i>layout specification</i>"</pre>
1120<p>The <i>layout specification</i> consists of a list of specifications
1121separated by the minus sign character ('-'). Each specification starts with a
1122letter and may include other information after the letter to define some
1123aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1124<dl>
1125 <dt><tt>E</tt></dt>
1126 <dd>Specifies that the target lays out data in big-endian form. That is, the
1127 bits with the most significance have the lowest address location.</dd>
1128 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1129 <dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1130 the bits with the least significance have the lowest address location.</dd>
1131 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1132 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
1133 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
1134 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
1135 too.</dd>
1136 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1137 <dd>This specifies the alignment for an integer type of a given bit
1138 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1139 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1140 <dd>This specifies the alignment for a vector type of a given bit
1141 <i>size</i>.</dd>
1142 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1143 <dd>This specifies the alignment for a floating point type of a given bit
1144 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1145 (double).</dd>
1146 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1147 <dd>This specifies the alignment for an aggregate type of a given bit
1148 <i>size</i>.</dd>
1149</dl>
1150<p>When constructing the data layout for a given target, LLVM starts with a
1151default set of specifications which are then (possibly) overriden by the
1152specifications in the <tt>datalayout</tt> keyword. The default specifications
1153are given in this list:</p>
1154<ul>
1155 <li><tt>E</tt> - big endian</li>
1156 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1157 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1158 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1159 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1160 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1161 <li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1162 alignment of 64-bits</li>
1163 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1164 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1165 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1166 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1167 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
1168</ul>
Chris Lattnerebec6782008-08-05 18:21:08 +0000[diff] [blame]1169<p>When LLVM is determining the alignment for a given type, it uses the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1170following rules:</p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1171<ol>
1172 <li>If the type sought is an exact match for one of the specifications, that
1173 specification is used.</li>
1174 <li>If no match is found, and the type sought is an integer type, then the
1175 smallest integer type that is larger than the bitwidth of the sought type is
1176 used. If none of the specifications are larger than the bitwidth then the the
1177 largest integer type is used. For example, given the default specifications
1178 above, the i7 type will use the alignment of i8 (next largest) while both
1179 i65 and i256 will use the alignment of i64 (largest specified).</li>
1180 <li>If no match is found, and the type sought is a vector type, then the
1181 largest vector type that is smaller than the sought vector type will be used
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1182 as a fall back. This happens because &lt;128 x double&gt; can be implemented
1183 in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1184</ol>
1185</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1186
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1187<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1188<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1189<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1190
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1191<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1192
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1193<p>The LLVM type system is one of the most important features of the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1194intermediate representation. Being typed enables a number of
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1195optimizations to be performed on the intermediate representation directly,
1196without having to do
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1197extra analyses on the side before the transformation. A strong type
1198system makes it easier to read the generated code and enables novel
1199analyses and transformations that are not feasible to perform on normal
1200three address code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1201
1202</div>
1203
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1204<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1205<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1206Classifications</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1207<div class="doc_text">
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1208<p>The types fall into a few useful
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1209classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1210
1211<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1212 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1213 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1214 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1215 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1216 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1217 </tr>
1218 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1219 <td><a href="#t_floating">floating point</a></td>
1220 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1221 </tr>
1222 <tr>
1223 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1224 <td><a href="#t_integer">integer</a>,
1225 <a href="#t_floating">floating point</a>,
1226 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1227 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1228 <a href="#t_struct">structure</a>,
1229 <a href="#t_array">array</a>,
Dan Gohmanade5faa2008-05-23 22:50:26 +0000[diff] [blame]1230 <a href="#t_label">label</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1231 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1232 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1233 <tr>
1234 <td><a href="#t_primitive">primitive</a></td>
1235 <td><a href="#t_label">label</a>,
1236 <a href="#t_void">void</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1237 <a href="#t_floating">floating point</a>.</td>
1238 </tr>
1239 <tr>
1240 <td><a href="#t_derived">derived</a></td>
1241 <td><a href="#t_integer">integer</a>,
1242 <a href="#t_array">array</a>,
1243 <a href="#t_function">function</a>,
1244 <a href="#t_pointer">pointer</a>,
1245 <a href="#t_struct">structure</a>,
1246 <a href="#t_pstruct">packed structure</a>,
1247 <a href="#t_vector">vector</a>,
1248 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1249 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1250 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1251 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1252</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1253
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1254<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1255most important. Values of these types are the only ones which can be
1256produced by instructions, passed as arguments, or used as operands to
Dan Gohmanc4b49eb2008-05-23 21:53:15 +0000[diff] [blame]1257instructions.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1258</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1259
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1260<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1261<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1262
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1263<div class="doc_text">
1264<p>The primitive types are the fundamental building blocks of the LLVM
1265system.</p>
1266
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1267</div>
1268
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1269<!-- _______________________________________________________________________ -->
1270<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1271
1272<div class="doc_text">
1273 <table>
1274 <tbody>
1275 <tr><th>Type</th><th>Description</th></tr>
1276 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1277 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1278 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1279 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1280 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1281 </tbody>
1282 </table>
1283</div>
1284
1285<!-- _______________________________________________________________________ -->
1286<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1287
1288<div class="doc_text">
1289<h5>Overview:</h5>
1290<p>The void type does not represent any value and has no size.</p>
1291
1292<h5>Syntax:</h5>
1293
1294<pre>
1295 void
1296</pre>
1297</div>
1298
1299<!-- _______________________________________________________________________ -->
1300<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1301
1302<div class="doc_text">
1303<h5>Overview:</h5>
1304<p>The label type represents code labels.</p>
1305
1306<h5>Syntax:</h5>
1307
1308<pre>
1309 label
1310</pre>
1311</div>
1312
1313
1314<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1315<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1316
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1317<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1318
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1319<p>The real power in LLVM comes from the derived types in the system.
1320This is what allows a programmer to represent arrays, functions,
1321pointers, and other useful types. Note that these derived types may be
1322recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1323
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1324</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1325
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1326<!-- _______________________________________________________________________ -->
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1327<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1328
1329<div class="doc_text">
1330
1331<h5>Overview:</h5>
1332<p>The integer type is a very simple derived type that simply specifies an
1333arbitrary bit width for the integer type desired. Any bit width from 1 bit to
13342^23-1 (about 8 million) can be specified.</p>
1335
1336<h5>Syntax:</h5>
1337
1338<pre>
1339 iN
1340</pre>
1341
1342<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1343value.</p>
1344
1345<h5>Examples:</h5>
1346<table class="layout">
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]1347 <tbody>
1348 <tr>
1349 <td><tt>i1</tt></td>
1350 <td>a single-bit integer.</td>
1351 </tr><tr>
1352 <td><tt>i32</tt></td>
1353 <td>a 32-bit integer.</td>
1354 </tr><tr>
1355 <td><tt>i1942652</tt></td>
1356 <td>a really big integer of over 1 million bits.</td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1357 </tr>
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]1358 </tbody>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1359</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1360
1361<p>Note that the code generator does not yet support large integer types
1362to be used as function return types. The specific limit on how large a
1363return type the code generator can currently handle is target-dependent;
1364currently it's often 64 bits for 32-bit targets and 128 bits for 64-bit
1365targets.</p>
1366
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1367</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1368
1369<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1370<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1371
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1372<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1373
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1374<h5>Overview:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1375
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1376<p>The array type is a very simple derived type that arranges elements
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1377sequentially in memory. The array type requires a size (number of
1378elements) and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1379
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1380<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1381
1382<pre>
1383 [&lt;# elements&gt; x &lt;elementtype&gt;]
1384</pre>
1385
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1386<p>The number of elements is a constant integer value; elementtype may
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1387be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1388
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1389<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1390<table class="layout">
1391 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1392 <td class="left"><tt>[40 x i32]</tt></td>
1393 <td class="left">Array of 40 32-bit integer values.</td>
1394 </tr>
1395 <tr class="layout">
1396 <td class="left"><tt>[41 x i32]</tt></td>
1397 <td class="left">Array of 41 32-bit integer values.</td>
1398 </tr>
1399 <tr class="layout">
1400 <td class="left"><tt>[4 x i8]</tt></td>
1401 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1402 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1403</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1404<p>Here are some examples of multidimensional arrays:</p>
1405<table class="layout">
1406 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1407 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1408 <td class="left">3x4 array of 32-bit integer values.</td>
1409 </tr>
1410 <tr class="layout">
1411 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1412 <td class="left">12x10 array of single precision floating point values.</td>
1413 </tr>
1414 <tr class="layout">
1415 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1416 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1417 </tr>
1418</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1419
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1420<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1421length array. Normally, accesses past the end of an array are undefined in
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1422LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1423As a special case, however, zero length arrays are recognized to be variable
1424length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1425type "{ i32, [0 x float]}", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1426
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1427<p>Note that the code generator does not yet support large aggregate types
1428to be used as function return types. The specific limit on how large an
1429aggregate return type the code generator can currently handle is
1430target-dependent, and also dependent on the aggregate element types.</p>
1431
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1432</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1433
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1434<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1435<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1436<div class="doc_text">
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1437
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1438<h5>Overview:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1439
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1440<p>The function type can be thought of as a function signature. It
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1441consists of a return type and a list of formal parameter types. The
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1442return type of a function type is a scalar type, a void type, or a struct type.
Devang Patel7a3ad1a2008-03-24 20:52:42 +0000[diff] [blame]1443If the return type is a struct type then all struct elements must be of first
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1444class types, and the struct must have at least one element.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1445
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1446<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1447
1448<pre>
1449 &lt;returntype list&gt; (&lt;parameter list&gt;)
1450</pre>
1451
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1452<p>...where '<tt>&lt;parameter list&gt;</tt>' is a comma-separated list of type
Misha Brukmanc24b7582004-08-12 20:16:08 +0000[diff] [blame]1453specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1454which indicates that the function takes a variable number of arguments.
1455Variable argument functions can access their arguments with the <a
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1456 href="#int_varargs">variable argument handling intrinsic</a> functions.
1457'<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1458<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1459
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1460<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1461<table class="layout">
1462 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1463 <td class="left"><tt>i32 (i32)</tt></td>
1464 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1465 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1466 </tr><tr class="layout">
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]1467 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1468 </tt></td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1469 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1470 an <tt>i16</tt> that should be sign extended and a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1471 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1472 <tt>float</tt>.
1473 </td>
1474 </tr><tr class="layout">
1475 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1476 <td class="left">A vararg function that takes at least one
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1477 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1478 which returns an integer. This is the signature for <tt>printf</tt> in
1479 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1480 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1481 </tr><tr class="layout">
1482 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukmanb0a57aa2008-11-27 06:41:20 +0000[diff] [blame]1483 <td class="left">A function taking an <tt>i32</tt>, returning two
1484 <tt>i32</tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1485 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1486 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1487</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1488
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1489</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1490<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1491<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1492<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1493<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1494<p>The structure type is used to represent a collection of data members
1495together in memory. The packing of the field types is defined to match
1496the ABI of the underlying processor. The elements of a structure may
1497be any type that has a size.</p>
1498<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1499and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1500field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1501instruction.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1502<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1503<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1504<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1505<table class="layout">
1506 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1507 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1508 <td class="left">A triple of three <tt>i32</tt> values</td>
1509 </tr><tr class="layout">
1510 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1511 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1512 second element is a <a href="#t_pointer">pointer</a> to a
1513 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1514 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1515 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1516</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1517
1518<p>Note that the code generator does not yet support large aggregate types
1519to be used as function return types. The specific limit on how large an
1520aggregate return type the code generator can currently handle is
1521target-dependent, and also dependent on the aggregate element types.</p>
1522
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1523</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1524
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1525<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1526<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1527</div>
1528<div class="doc_text">
1529<h5>Overview:</h5>
1530<p>The packed structure type is used to represent a collection of data members
1531together in memory. There is no padding between fields. Further, the alignment
1532of a packed structure is 1 byte. The elements of a packed structure may
1533be any type that has a size.</p>
1534<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1535and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1536field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1537instruction.</p>
1538<h5>Syntax:</h5>
1539<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1540<h5>Examples:</h5>
1541<table class="layout">
1542 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1543 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1544 <td class="left">A triple of three <tt>i32</tt> values</td>
1545 </tr><tr class="layout">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1546 <td class="left">
1547<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1548 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1549 second element is a <a href="#t_pointer">pointer</a> to a
1550 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1551 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1552 </tr>
1553</table>
1554</div>
1555
1556<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1557<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1558<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1559<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1560<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]1561reference to another object, which must live in memory. Pointer types may have
1562an optional address space attribute defining the target-specific numbered
1563address space where the pointed-to object resides. The default address space is
1564zero.</p>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1565
1566<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does
Chris Lattnere220e8c2009-02-08 22:21:28 +0000[diff] [blame]1567it permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1568
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1569<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1570<pre> &lt;type&gt; *<br></pre>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1571<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1572<table class="layout">
1573 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]1574 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1575 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1576 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1577 </tr>
1578 <tr class="layout">
1579 <td class="left"><tt>i32 (i32 *) *</tt></td>
1580 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1581 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1582 <tt>i32</tt>.</td>
1583 </tr>
1584 <tr class="layout">
1585 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1586 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1587 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1588 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1589</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1590</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1591
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1592<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1593<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1594<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1595
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1596<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1597
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1598<p>A vector type is a simple derived type that represents a vector
1599of elements. Vector types are used when multiple primitive data
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1600are operated in parallel using a single instruction (SIMD).
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1601A vector type requires a size (number of
Chris Lattnerb8d172f2005-11-10 01:44:22 +0000[diff] [blame]1602elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1603of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1604considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1605
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1606<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1607
1608<pre>
1609 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1610</pre>
1611
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1612<p>The number of elements is a constant integer value; elementtype may
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1613be any integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1614
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1615<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1616
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1617<table class="layout">
1618 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1619 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1620 <td class="left">Vector of 4 32-bit integer values.</td>
1621 </tr>
1622 <tr class="layout">
1623 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1624 <td class="left">Vector of 8 32-bit floating-point values.</td>
1625 </tr>
1626 <tr class="layout">
1627 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1628 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1629 </tr>
1630</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1631
1632<p>Note that the code generator does not yet support large vector types
1633to be used as function return types. The specific limit on how large a
1634vector return type codegen can currently handle is target-dependent;
1635currently it's often a few times longer than a hardware vector register.</p>
1636
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1637</div>
1638
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1639<!-- _______________________________________________________________________ -->
1640<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1641<div class="doc_text">
1642
1643<h5>Overview:</h5>
1644
1645<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksen8ac04ff2007-10-14 00:34:53 +0000[diff] [blame]1646corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1647In LLVM, opaque types can eventually be resolved to any type (not just a
1648structure type).</p>
1649
1650<h5>Syntax:</h5>
1651
1652<pre>
1653 opaque
1654</pre>
1655
1656<h5>Examples:</h5>
1657
1658<table class="layout">
1659 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1660 <td class="left"><tt>opaque</tt></td>
1661 <td class="left">An opaque type.</td>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1662 </tr>
1663</table>
1664</div>
1665
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1666<!-- ======================================================================= -->
1667<div class="doc_subsection">
1668 <a name="t_uprefs">Type Up-references</a>
1669</div>
1670
1671<div class="doc_text">
1672<h5>Overview:</h5>
1673<p>
1674An "up reference" allows you to refer to a lexically enclosing type without
1675requiring it to have a name. For instance, a structure declaration may contain a
1676pointer to any of the types it is lexically a member of. Example of up
1677references (with their equivalent as named type declarations) include:</p>
1678
1679<pre>
1680 { \2 * } %x = type { %t* }
1681 { \2 }* %y = type { %y }*
1682 \1* %z = type %z*
1683</pre>
1684
1685<p>
1686An up reference is needed by the asmprinter for printing out cyclic types when
1687there is no declared name for a type in the cycle. Because the asmprinter does
1688not want to print out an infinite type string, it needs a syntax to handle
1689recursive types that have no names (all names are optional in llvm IR).
1690</p>
1691
1692<h5>Syntax:</h5>
1693<pre>
1694 \&lt;level&gt;
1695</pre>
1696
1697<p>
1698The level is the count of the lexical type that is being referred to.
1699</p>
1700
1701<h5>Examples:</h5>
1702
1703<table class="layout">
1704 <tr class="layout">
1705 <td class="left"><tt>\1*</tt></td>
1706 <td class="left">Self-referential pointer.</td>
1707 </tr>
1708 <tr class="layout">
1709 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
1710 <td class="left">Recursive structure where the upref refers to the out-most
1711 structure.</td>
1712 </tr>
1713</table>
1714</div>
1715
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1716
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1717<!-- *********************************************************************** -->
1718<div class="doc_section"> <a name="constants">Constants</a> </div>
1719<!-- *********************************************************************** -->
1720
1721<div class="doc_text">
1722
1723<p>LLVM has several different basic types of constants. This section describes
1724them all and their syntax.</p>
1725
1726</div>
1727
1728<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1729<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1730
1731<div class="doc_text">
1732
1733<dl>
1734 <dt><b>Boolean constants</b></dt>
1735
1736 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1737 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1738 </dd>
1739
1740 <dt><b>Integer constants</b></dt>
1741
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1742 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1743 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1744 integer types.
1745 </dd>
1746
1747 <dt><b>Floating point constants</b></dt>
1748
1749 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1750 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]1751 notation (see below). The assembler requires the exact decimal value of
1752 a floating-point constant. For example, the assembler accepts 1.25 but
1753 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1754 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1755
1756 <dt><b>Null pointer constants</b></dt>
1757
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1758 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1759 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1760
1761</dl>
1762
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1763<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1764of floating point constants. For example, the form '<tt>double
17650x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
17664.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1767(and the only time that they are generated by the disassembler) is when a
1768floating point constant must be emitted but it cannot be represented as a
1769decimal floating point number. For example, NaN's, infinities, and other
1770special values are represented in their IEEE hexadecimal format so that
1771assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1772
1773</div>
1774
1775<!-- ======================================================================= -->
1776<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1777</div>
1778
1779<div class="doc_text">
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]1780<p>Aggregate constants arise from aggregation of simple constants
1781and smaller aggregate constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1782
1783<dl>
1784 <dt><b>Structure constants</b></dt>
1785
1786 <dd>Structure constants are represented with notation similar to structure
1787 type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner64910ee2007-12-25 20:34:52 +0000[diff] [blame]1788 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1789 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]1790 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1791 types of elements must match those specified by the type.
1792 </dd>
1793
1794 <dt><b>Array constants</b></dt>
1795
1796 <dd>Array constants are represented with notation similar to array type
1797 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1798 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1799 constants must have <a href="#t_array">array type</a>, and the number and
1800 types of elements must match those specified by the type.
1801 </dd>
1802
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1803 <dt><b>Vector constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1804
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1805 <dd>Vector constants are represented with notation similar to vector type
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1806 definitions (a comma separated list of elements, surrounded by
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1807 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]1808 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1809 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1810 match those specified by the type.
1811 </dd>
1812
1813 <dt><b>Zero initialization</b></dt>
1814
1815 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1816 value to zero of <em>any</em> type, including scalar and aggregate types.
1817 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]1818 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1819 initializers.
1820 </dd>
1821</dl>
1822
1823</div>
1824
1825<!-- ======================================================================= -->
1826<div class="doc_subsection">
1827 <a name="globalconstants">Global Variable and Function Addresses</a>
1828</div>
1829
1830<div class="doc_text">
1831
1832<p>The addresses of <a href="#globalvars">global variables</a> and <a
1833href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1834constants. These constants are explicitly referenced when the <a
1835href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1836href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1837file:</p>
1838
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1839<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1840<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]1841@X = global i32 17
1842@Y = global i32 42
1843@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1844</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1845</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1846
1847</div>
1848
1849<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1850<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1851<div class="doc_text">
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1852 <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]1853 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1854 a constant is permitted.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1855
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1856 <p>Undefined values indicate to the compiler that the program is well defined
1857 no matter what value is used, giving the compiler more freedom to optimize.
1858 </p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1859</div>
1860
1861<!-- ======================================================================= -->
1862<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1863</div>
1864
1865<div class="doc_text">
1866
1867<p>Constant expressions are used to allow expressions involving other constants
1868to be used as constants. Constant expressions may be of any <a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1869href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1870that does not have side effects (e.g. load and call are not supported). The
1871following is the syntax for constant expressions:</p>
1872
1873<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1874 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1875 <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]1876 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1877
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1878 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1879 <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]1880 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]1881
1882 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1883 <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]1884 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]1885
1886 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1887 <dd>Truncate a floating point constant to another floating point type. The
1888 size of CST must be larger than the size of TYPE. Both types must be
1889 floating point.</dd>
1890
1891 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1892 <dd>Floating point extend a constant to another type. The size of CST must be
1893 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1894
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]1895 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1896 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1897 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1898 or vector floating point 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 integer type,
1900 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>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1903 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1904 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1905 or vector floating point 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 integer type,
1907 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1908
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1909 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1910 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1911 constant. TYPE must be a scalar or vector floating point type. CST must be of
1912 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1913 of the same number of elements. If the value won't fit in the floating point
1914 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1915
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1916 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1917 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1918 constant. TYPE must be a scalar or vector floating point type. CST must be of
1919 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1920 of the same number of elements. If the value won't fit in the floating point
1921 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1922
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1923 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1924 <dd>Convert a pointer typed constant to the corresponding integer constant
1925 TYPE must be an integer type. CST must be of pointer type. The CST value is
1926 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1927
1928 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1929 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1930 pointer type. CST must be of integer type. The CST value is zero extended,
1931 truncated, or unchanged to make it fit in a pointer size. This one is
1932 <i>really</i> dangerous!</dd>
1933
1934 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1935 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1936 identical (same number of bits). The conversion is done as if the CST value
1937 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]1938 with this operator, just the type. This can be used for conversion of
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1939 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]1940 pointers it is only valid to cast to another pointer type. It is not valid
1941 to bitcast to or from an aggregate type.
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1942 </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1943
1944 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1945
1946 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1947 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1948 instruction, the index list may have zero or more indexes, which are required
1949 to make sense for the type of "CSTPTR".</dd>
1950
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1951 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1952
1953 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1954 constants.</dd>
1955
1956 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1957 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1958
1959 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1960 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1961
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]1962 <dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
1963 <dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
1964
1965 <dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
1966 <dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
1967
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1968 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1969
1970 <dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1971 operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1972
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1973 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1974
1975 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1976 operation</a> on constants.</dd>
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1977
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1978
1979 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1980
1981 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1982 operation</a> on constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1983
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1984 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1985
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1986 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1987 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1988 binary</a> operations. The constraints on operands are the same as those for
1989 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1990 values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1991</dl>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1992</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]1993
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1994<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1995<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1996<!-- *********************************************************************** -->
1997
1998<!-- ======================================================================= -->
1999<div class="doc_subsection">
2000<a name="inlineasm">Inline Assembler Expressions</a>
2001</div>
2002
2003<div class="doc_text">
2004
2005<p>
2006LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
2007Module-Level Inline Assembly</a>) through the use of a special value. This
2008value represents the inline assembler as a string (containing the instructions
2009to emit), a list of operand constraints (stored as a string), and a flag that
2010indicates whether or not the inline asm expression has side effects. An example
2011inline assembler expression is:
2012</p>
2013
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2014<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2015<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2016i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2017</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2018</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2019
2020<p>
2021Inline assembler expressions may <b>only</b> be used as the callee operand of
2022a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
2023</p>
2024
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2025<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2026<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2027%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]2028</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2029</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2030
2031<p>
2032Inline asms with side effects not visible in the constraint list must be marked
2033as having side effects. This is done through the use of the
2034'<tt>sideeffect</tt>' keyword, like so:
2035</p>
2036
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2037<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2038<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2039call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2040</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2041</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2042
2043<p>TODO: The format of the asm and constraints string still need to be
2044documented here. Constraints on what can be done (e.g. duplication, moving, etc
Chris Lattner4f993352008-10-04 18:36:02 +0000[diff] [blame]2045need to be documented). This is probably best done by reference to another
2046document that covers inline asm from a holistic perspective.
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2047</p>
2048
2049</div>
2050
2051<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2052<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
2053<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2054
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2055<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2056
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2057<p>The LLVM instruction set consists of several different
2058classifications of instructions: <a href="#terminators">terminator
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2059instructions</a>, <a href="#binaryops">binary instructions</a>,
2060<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2061 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
2062instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2063
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2064</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2065
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2066<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2067<div class="doc_subsection"> <a name="terminators">Terminator
2068Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2069
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2070<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2071
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2072<p>As mentioned <a href="#functionstructure">previously</a>, every
2073basic block in a program ends with a "Terminator" instruction, which
2074indicates which block should be executed after the current block is
2075finished. These terminator instructions typically yield a '<tt>void</tt>'
2076value: they produce control flow, not values (the one exception being
2077the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2078<p>There are six different terminator instructions: the '<a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2079 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
2080instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2081the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
2082 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
2083 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2084
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2085</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2086
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2087<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2088<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
2089Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2090<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2091<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2092<pre>
2093 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]2094 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2095</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2096
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2097<h5>Overview:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2098
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2099<p>The '<tt>ret</tt>' instruction is used to return control flow (and
2100optionally a value) from a function back to the caller.</p>
John Criswell4457dc92004-04-09 16:48:45 +0000[diff] [blame]2101<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2102returns a value and then causes control flow, and one that just causes
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2103control flow to occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2104
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2105<h5>Arguments:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2106
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2107<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
2108the return value. The type of the return value must be a
2109'<a href="#t_firstclass">first class</a>' type.</p>
2110
2111<p>A function is not <a href="#wellformed">well formed</a> if
2112it it has a non-void return type and contains a '<tt>ret</tt>'
2113instruction with no return value or a return value with a type that
2114does not match its type, or if it has a void return type and contains
2115a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2116
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2117<h5>Semantics:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2118
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2119<p>When the '<tt>ret</tt>' instruction is executed, control flow
2120returns back to the calling function's context. If the caller is a "<a
John Criswellfa081872004-06-25 15:16:57 +0000[diff] [blame]2121 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2122the instruction after the call. If the caller was an "<a
2123 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2124at the beginning of the "normal" destination block. If the instruction
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2125returns a value, that value shall set the call or invoke instruction's
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]2126return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2127
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2128<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2129
2130<pre>
2131 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2132 ret void <i>; Return from a void function</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2133 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]2134</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2135
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]2136<p>Note that the code generator does not yet fully support large
2137 return values. The specific sizes that are currently supported are
2138 dependent on the target. For integers, on 32-bit targets the limit
2139 is often 64 bits, and on 64-bit targets the limit is often 128 bits.
2140 For aggregate types, the current limits are dependent on the element
2141 types; for example targets are often limited to 2 total integer
2142 elements and 2 total floating-point elements.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2143
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2144</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2145<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2146<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2147<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2148<h5>Syntax:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2149<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]2150</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2151<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2152<p>The '<tt>br</tt>' instruction is used to cause control flow to
2153transfer to a different basic block in the current function. There are
2154two forms of this instruction, corresponding to a conditional branch
2155and an unconditional branch.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2156<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2157<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2158single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]2159unconditional form of the '<tt>br</tt>' instruction takes a single
2160'<tt>label</tt>' value as a target.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2161<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2162<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2163argument is evaluated. If the value is <tt>true</tt>, control flows
2164to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2165control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2166<h5>Example:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2167<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]2168 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]2169</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2170<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2171<div class="doc_subsubsection">
2172 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2173</div>
2174
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2175<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2176<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2177
2178<pre>
2179 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2180</pre>
2181
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2182<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2183
2184<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
2185several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2186instruction, allowing a branch to occur to one of many possible
2187destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2188
2189
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2190<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2191
2192<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
2193comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
2194an array of pairs of comparison value constants and '<tt>label</tt>'s. The
2195table is not allowed to contain duplicate constant entries.</p>
2196
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2197<h5>Semantics:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2198
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2199<p>The <tt>switch</tt> instruction specifies a table of values and
2200destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]2201table is searched for the given value. If the value is found, control flow is
2202transfered to the corresponding destination; otherwise, control flow is
2203transfered to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2204
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2205<h5>Implementation:</h5>
2206
2207<p>Depending on properties of the target machine and the particular
2208<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]2209ways. For example, it could be generated as a series of chained conditional
2210branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2211
2212<h5>Example:</h5>
2213
2214<pre>
2215 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2216 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2217 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2218
2219 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2220 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2221
2222 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2223 switch i32 %val, label %otherwise [ i32 0, label %onzero
2224 i32 1, label %onone
2225 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2226</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2227</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2228
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2229<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2230<div class="doc_subsubsection">
2231 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2232</div>
2233
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2234<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2235
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2236<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2237
2238<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2239 &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]2240 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2241</pre>
2242
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2243<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2244
2245<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
2246function, with the possibility of control flow transfer to either the
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2247'<tt>normal</tt>' label or the
2248'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2249"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
2250"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2251href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]2252continued at the dynamically nearest "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2253
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2254<h5>Arguments:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2255
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2256<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2257
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2258<ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2259 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]2260 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2261 convention</a> the call should use. If none is specified, the call defaults
2262 to using C calling conventions.
2263 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2264
2265 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
2266 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
2267 and '<tt>inreg</tt>' attributes are valid here.</li>
2268
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2269 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
2270 function value being invoked. In most cases, this is a direct function
2271 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
2272 an arbitrary pointer to function value.
2273 </li>
2274
2275 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
2276 function to be invoked. </li>
2277
2278 <li>'<tt>function args</tt>': argument list whose types match the function
2279 signature argument types. If the function signature indicates the function
2280 accepts a variable number of arguments, the extra arguments can be
2281 specified. </li>
2282
2283 <li>'<tt>normal label</tt>': the label reached when the called function
2284 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
2285
2286 <li>'<tt>exception label</tt>': the label reached when a callee returns with
2287 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
2288
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2289 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2290 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2291 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2292</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2293
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2294<h5>Semantics:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2295
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2296<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2297href="#i_call">call</a></tt>' instruction in most regards. The primary
2298difference is that it establishes an association with a label, which is used by
2299the runtime library to unwind the stack.</p>
2300
2301<p>This instruction is used in languages with destructors to ensure that proper
2302cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2303exception. Additionally, this is important for implementation of
2304'<tt>catch</tt>' clauses in high-level languages that support them.</p>
2305
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2306<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2307<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2308 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2309 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2310 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2311 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2312</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2313</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2314
2315
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2316<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2317
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2318<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2319Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2320
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2321<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2322
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2323<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2324<pre>
2325 unwind
2326</pre>
2327
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2328<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2329
2330<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
2331at the first callee in the dynamic call stack which used an <a
2332href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
2333primarily used to implement exception handling.</p>
2334
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2335<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2336
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]2337<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2338immediately halt. The dynamic call stack is then searched for the first <a
2339href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
2340execution continues at the "exceptional" destination block specified by the
2341<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
2342dynamic call chain, undefined behavior results.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2343</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2344
2345<!-- _______________________________________________________________________ -->
2346
2347<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2348Instruction</a> </div>
2349
2350<div class="doc_text">
2351
2352<h5>Syntax:</h5>
2353<pre>
2354 unreachable
2355</pre>
2356
2357<h5>Overview:</h5>
2358
2359<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
2360instruction is used to inform the optimizer that a particular portion of the
2361code is not reachable. This can be used to indicate that the code after a
2362no-return function cannot be reached, and other facts.</p>
2363
2364<h5>Semantics:</h5>
2365
2366<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
2367</div>
2368
2369
2370
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2371<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2372<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2373<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2374<p>Binary operators are used to do most of the computation in a
Chris Lattner5a158142008-04-01 18:47:32 +0000[diff] [blame]2375program. They require two operands of the same type, execute an operation on them, and
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2376produce a single value. The operands might represent
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2377multiple 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]2378The result value has the same type as its operands.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2379<p>There are several different binary operators:</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2380</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2381<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2382<div class="doc_subsubsection">
2383 <a name="i_add">'<tt>add</tt>' Instruction</a>
2384</div>
2385
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2386<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2387
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2388<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2389
2390<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2391 &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]2392</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2393
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2394<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2395
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2396<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2397
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2398<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2399
2400<p>The two arguments to the '<tt>add</tt>' instruction must be <a
2401 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
2402 <a href="#t_vector">vector</a> values. Both arguments must have identical
2403 types.</p>
2404
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2405<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2406
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2407<p>The value produced is the integer or floating point sum of the two
2408operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2409
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2410<p>If an integer sum has unsigned overflow, the result returned is the
2411mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2412the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2413
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2414<p>Because LLVM integers use a two's complement representation, this
2415instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2416
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2417<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2418
2419<pre>
2420 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2421</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2422</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2423<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2424<div class="doc_subsubsection">
2425 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2426</div>
2427
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2428<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2429
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2430<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2431
2432<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2433 &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]2434</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2435
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2436<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2437
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2438<p>The '<tt>sub</tt>' instruction returns the difference of its two
2439operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2440
2441<p>Note that the '<tt>sub</tt>' instruction is used to represent the
2442'<tt>neg</tt>' instruction present in most other intermediate
2443representations.</p>
2444
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2445<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2446
2447<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
2448 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2449 or <a href="#t_vector">vector</a> values. Both arguments must have identical
2450 types.</p>
2451
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2452<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2453
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2454<p>The value produced is the integer or floating point difference of
2455the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2456
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2457<p>If an integer difference has unsigned overflow, the result returned is the
2458mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2459the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2460
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2461<p>Because LLVM integers use a two's complement representation, this
2462instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2463
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2464<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2465<pre>
2466 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2467 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2468</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2469</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2470
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2471<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2472<div class="doc_subsubsection">
2473 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2474</div>
2475
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2476<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2477
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2478<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2479<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]2480</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2481<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2482<p>The '<tt>mul</tt>' instruction returns the product of its two
2483operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2484
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2485<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2486
2487<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
2488href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2489or <a href="#t_vector">vector</a> values. Both arguments must have identical
2490types.</p>
2491
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2492<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2493
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2494<p>The value produced is the integer or floating point product of the
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2495two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2496
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2497<p>If the result of an integer multiplication has unsigned overflow,
2498the result returned is the mathematical result modulo
24992<sup>n</sup>, where n is the bit width of the result.</p>
2500<p>Because LLVM integers use a two's complement representation, and the
2501result is the same width as the operands, this instruction returns the
2502correct result for both signed and unsigned integers. If a full product
2503(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
2504should be sign-extended or zero-extended as appropriate to the
2505width of the full product.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2506<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2507<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]2508</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2509</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2510
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2511<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2512<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2513</a></div>
2514<div class="doc_text">
2515<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2516<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]2517</pre>
2518<h5>Overview:</h5>
2519<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2520operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2521
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2522<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2523
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2524<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2525<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2526values. Both arguments must have identical types.</p>
2527
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2528<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2529
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2530<p>The value produced is the unsigned integer quotient of the two operands.</p>
2531<p>Note that unsigned integer division and signed integer division are distinct
2532operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2533<p>Division by zero leads to undefined behavior.</p>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2534<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2535<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]2536</pre>
2537</div>
2538<!-- _______________________________________________________________________ -->
2539<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2540</a> </div>
2541<div class="doc_text">
2542<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2543<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2544 &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]2545</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2546
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2547<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2548
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2549<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2550operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2551
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2552<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2553
2554<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2555<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2556values. Both arguments must have identical types.</p>
2557
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2558<h5>Semantics:</h5>
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2559<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]2560<p>Note that signed integer division and unsigned integer division are distinct
2561operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2562<p>Division by zero leads to undefined behavior. Overflow also leads to
2563undefined behavior; this is a rare case, but can occur, for example,
2564by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2565<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2566<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]2567</pre>
2568</div>
2569<!-- _______________________________________________________________________ -->
2570<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2571Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2572<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2573<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2574<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2575 &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]2576</pre>
2577<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2578
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2579<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2580operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2581
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2582<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2583
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2584<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2585<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2586of floating point values. Both arguments must have identical types.</p>
2587
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2588<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2589
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2590<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2591
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2592<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2593
2594<pre>
2595 &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]2596</pre>
2597</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2598
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2599<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2600<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2601</div>
2602<div class="doc_text">
2603<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2604<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]2605</pre>
2606<h5>Overview:</h5>
2607<p>The '<tt>urem</tt>' instruction returns the remainder from the
2608unsigned division of its two arguments.</p>
2609<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2610<p>The two arguments to the '<tt>urem</tt>' instruction must be
2611<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2612values. Both arguments must have identical types.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2613<h5>Semantics:</h5>
2614<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2615This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2616<p>Note that unsigned integer remainder and signed integer remainder are
2617distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
2618<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2619<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2620<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]2621</pre>
2622
2623</div>
2624<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2625<div class="doc_subsubsection">
2626 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
2627</div>
2628
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2629<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2630
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2631<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2632
2633<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2634 &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]2635</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2636
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2637<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2638
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2639<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2640signed division of its two operands. This instruction can also take
2641<a href="#t_vector">vector</a> versions of the values in which case
2642the elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]2643
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2644<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2645
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2646<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2647<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2648values. Both arguments must have identical types.</p>
2649
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2650<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2651
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2652<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2653has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
2654operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2655a value. For more information about the difference, see <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2656 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2657Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencer64f5c6c2007-03-24 22:40:44 +0000[diff] [blame]2658please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2659Wikipedia: modulo operation</a>.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2660<p>Note that signed integer remainder and unsigned integer remainder are
2661distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
2662<p>Taking the remainder of a division by zero leads to undefined behavior.
2663Overflow also leads to undefined behavior; this is a rare case, but can occur,
2664for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
2665(The remainder doesn't actually overflow, but this rule lets srem be
2666implemented using instructions that return both the result of the division
2667and the remainder.)</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2668<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2669<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]2670</pre>
2671
2672</div>
2673<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2674<div class="doc_subsubsection">
2675 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
2676
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2677<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2678
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2679<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2680<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]2681</pre>
2682<h5>Overview:</h5>
2683<p>The '<tt>frem</tt>' instruction returns the remainder from the
2684division of its two operands.</p>
2685<h5>Arguments:</h5>
2686<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2687<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2688of floating point values. Both arguments must have identical types.</p>
2689
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2690<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2691
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2692<p>This instruction returns the <i>remainder</i> of a division.
2693The remainder has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2694
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2695<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2696
2697<pre>
2698 &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]2699</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2700</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]2701
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2702<!-- ======================================================================= -->
2703<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2704Operations</a> </div>
2705<div class="doc_text">
2706<p>Bitwise binary operators are used to do various forms of
2707bit-twiddling in a program. They are generally very efficient
2708instructions and can commonly be strength reduced from other
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2709instructions. They require two operands of the same type, execute an operation on them,
2710and 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]2711</div>
2712
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2713<!-- _______________________________________________________________________ -->
2714<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2715Instruction</a> </div>
2716<div class="doc_text">
2717<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2718<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]2719</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2720
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2721<h5>Overview:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2722
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2723<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2724the left a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2725
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2726<h5>Arguments:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2727
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2728<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2729 href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2730type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2731
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2732<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2733
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2734<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
2735where 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]2736equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
2737If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
2738corresponding shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2739
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2740<h5>Example:</h5><pre>
2741 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2742 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2743 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2744 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]2745 &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]2746</pre>
2747</div>
2748<!-- _______________________________________________________________________ -->
2749<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2750Instruction</a> </div>
2751<div class="doc_text">
2752<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2753<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]2754</pre>
2755
2756<h5>Overview:</h5>
2757<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2758operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2759
2760<h5>Arguments:</h5>
2761<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2762<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]2763type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2764
2765<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2766
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2767<p>This instruction always performs a logical shift right operation. The most
2768significant bits of the result will be filled with zero bits after the
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2769shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
Mon P Wang01f8d092008-12-10 08:55:09 +0000[diff] [blame]2770the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
2771vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
2772amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2773
2774<h5>Example:</h5>
2775<pre>
2776 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2777 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2778 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2779 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2780 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]2781 &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]2782</pre>
2783</div>
2784
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2785<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2786<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2787Instruction</a> </div>
2788<div class="doc_text">
2789
2790<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2791<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]2792</pre>
2793
2794<h5>Overview:</h5>
2795<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2796operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2797
2798<h5>Arguments:</h5>
2799<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2800<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]2801type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2802
2803<h5>Semantics:</h5>
2804<p>This instruction always performs an arithmetic shift right operation,
2805The most significant bits of the result will be filled with the sign bit
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2806of <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]2807larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
2808arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
2809corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2810
2811<h5>Example:</h5>
2812<pre>
2813 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2814 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2815 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2816 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2817 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]2818 &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]2819</pre>
2820</div>
2821
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2822<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2823<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2824Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2825
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2826<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2827
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2828<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2829
2830<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2831 &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]2832</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2833
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2834<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2835
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2836<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2837its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2838
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2839<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2840
2841<p>The two arguments to the '<tt>and</tt>' instruction must be
2842<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2843values. Both arguments must have identical types.</p>
2844
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2845<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2846<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2847<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2848<div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2849<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2850 <tbody>
2851 <tr>
2852 <td>In0</td>
2853 <td>In1</td>
2854 <td>Out</td>
2855 </tr>
2856 <tr>
2857 <td>0</td>
2858 <td>0</td>
2859 <td>0</td>
2860 </tr>
2861 <tr>
2862 <td>0</td>
2863 <td>1</td>
2864 <td>0</td>
2865 </tr>
2866 <tr>
2867 <td>1</td>
2868 <td>0</td>
2869 <td>0</td>
2870 </tr>
2871 <tr>
2872 <td>1</td>
2873 <td>1</td>
2874 <td>1</td>
2875 </tr>
2876 </tbody>
2877</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2878</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2879<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2880<pre>
2881 &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]2882 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2883 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2884</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2885</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2886<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2887<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2888<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2889<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2890<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]2891</pre>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2892<h5>Overview:</h5>
2893<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2894or of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2895<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2896
2897<p>The two arguments to the '<tt>or</tt>' instruction must be
2898<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2899values. Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2900<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2901<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2902<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2903<div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2904<table border="1" cellspacing="0" cellpadding="4">
2905 <tbody>
2906 <tr>
2907 <td>In0</td>
2908 <td>In1</td>
2909 <td>Out</td>
2910 </tr>
2911 <tr>
2912 <td>0</td>
2913 <td>0</td>
2914 <td>0</td>
2915 </tr>
2916 <tr>
2917 <td>0</td>
2918 <td>1</td>
2919 <td>1</td>
2920 </tr>
2921 <tr>
2922 <td>1</td>
2923 <td>0</td>
2924 <td>1</td>
2925 </tr>
2926 <tr>
2927 <td>1</td>
2928 <td>1</td>
2929 <td>1</td>
2930 </tr>
2931 </tbody>
2932</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2933</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2934<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2935<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2936 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2937 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2938</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2939</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2940<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2941<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2942Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2943<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2944<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2945<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]2946</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2947<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2948<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2949or of its two operands. The <tt>xor</tt> is used to implement the
2950"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2951<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2952<p>The two arguments to the '<tt>xor</tt>' instruction must be
2953<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2954values. Both arguments must have identical types.</p>
2955
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2956<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2957
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2958<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2959<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2960<div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2961<table border="1" cellspacing="0" cellpadding="4">
2962 <tbody>
2963 <tr>
2964 <td>In0</td>
2965 <td>In1</td>
2966 <td>Out</td>
2967 </tr>
2968 <tr>
2969 <td>0</td>
2970 <td>0</td>
2971 <td>0</td>
2972 </tr>
2973 <tr>
2974 <td>0</td>
2975 <td>1</td>
2976 <td>1</td>
2977 </tr>
2978 <tr>
2979 <td>1</td>
2980 <td>0</td>
2981 <td>1</td>
2982 </tr>
2983 <tr>
2984 <td>1</td>
2985 <td>1</td>
2986 <td>0</td>
2987 </tr>
2988 </tbody>
2989</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2990</div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2991<p> </p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2992<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2993<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2994 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2995 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2996 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2997</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2998</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2999
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3000<!-- ======================================================================= -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3001<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3002 <a name="vectorops">Vector Operations</a>
3003</div>
3004
3005<div class="doc_text">
3006
3007<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3008target-independent manner. These instructions cover the element-access and
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3009vector-specific operations needed to process vectors effectively. While LLVM
3010does directly support these vector operations, many sophisticated algorithms
3011will want to use target-specific intrinsics to take full advantage of a specific
3012target.</p>
3013
3014</div>
3015
3016<!-- _______________________________________________________________________ -->
3017<div class="doc_subsubsection">
3018 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
3019</div>
3020
3021<div class="doc_text">
3022
3023<h5>Syntax:</h5>
3024
3025<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3026 &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]3027</pre>
3028
3029<h5>Overview:</h5>
3030
3031<p>
3032The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3033element from a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3034</p>
3035
3036
3037<h5>Arguments:</h5>
3038
3039<p>
3040The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3041value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3042an index indicating the position from which to extract the element.
3043The index may be a variable.</p>
3044
3045<h5>Semantics:</h5>
3046
3047<p>
3048The result is a scalar of the same type as the element type of
3049<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
3050<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3051results are undefined.
3052</p>
3053
3054<h5>Example:</h5>
3055
3056<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3057 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3058</pre>
3059</div>
3060
3061
3062<!-- _______________________________________________________________________ -->
3063<div class="doc_subsubsection">
3064 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
3065</div>
3066
3067<div class="doc_text">
3068
3069<h5>Syntax:</h5>
3070
3071<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]3072 &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]3073</pre>
3074
3075<h5>Overview:</h5>
3076
3077<p>
3078The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3079element into a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3080</p>
3081
3082
3083<h5>Arguments:</h5>
3084
3085<p>
3086The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3087value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3088scalar value whose type must equal the element type of the first
3089operand. The third operand is an index indicating the position at
3090which to insert the value. The index may be a variable.</p>
3091
3092<h5>Semantics:</h5>
3093
3094<p>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3095The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3096element values are those of <tt>val</tt> except at position
3097<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
3098exceeds the length of <tt>val</tt>, the results are undefined.
3099</p>
3100
3101<h5>Example:</h5>
3102
3103<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3104 %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]3105</pre>
3106</div>
3107
3108<!-- _______________________________________________________________________ -->
3109<div class="doc_subsubsection">
3110 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3111</div>
3112
3113<div class="doc_text">
3114
3115<h5>Syntax:</h5>
3116
3117<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3118 &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]3119</pre>
3120
3121<h5>Overview:</h5>
3122
3123<p>
3124The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3125from two input vectors, returning a vector with the same element type as
3126the input and length that is the same as the shuffle mask.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3127</p>
3128
3129<h5>Arguments:</h5>
3130
3131<p>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3132The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
3133with types that match each other. The third argument is a shuffle mask whose
3134element type is always 'i32'. The result of the instruction is a vector whose
3135length is the same as the shuffle mask and whose element type is the same as
3136the element type of the first two operands.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3137</p>
3138
3139<p>
3140The shuffle mask operand is required to be a constant vector with either
3141constant integer or undef values.
3142</p>
3143
3144<h5>Semantics:</h5>
3145
3146<p>
3147The elements of the two input vectors are numbered from left to right across
3148both of the vectors. The shuffle mask operand specifies, for each element of
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3149the result vector, which element of the two input vectors the result element
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3150gets. The element selector may be undef (meaning "don't care") and the second
3151operand may be undef if performing a shuffle from only one vector.
3152</p>
3153
3154<h5>Example:</h5>
3155
3156<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3157 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3158 &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]3159 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
3160 &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]3161 %result = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
3162 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
3163 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
3164 &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]3165</pre>
3166</div>
3167
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]3168
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3169<!-- ======================================================================= -->
3170<div class="doc_subsection">
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3171 <a name="aggregateops">Aggregate Operations</a>
3172</div>
3173
3174<div class="doc_text">
3175
3176<p>LLVM supports several instructions for working with aggregate values.
3177</p>
3178
3179</div>
3180
3181<!-- _______________________________________________________________________ -->
3182<div class="doc_subsubsection">
3183 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3184</div>
3185
3186<div class="doc_text">
3187
3188<h5>Syntax:</h5>
3189
3190<pre>
3191 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3192</pre>
3193
3194<h5>Overview:</h5>
3195
3196<p>
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3197The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3198or array element from an aggregate value.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3199</p>
3200
3201
3202<h5>Arguments:</h5>
3203
3204<p>
3205The first operand of an '<tt>extractvalue</tt>' instruction is a
3206value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3207type. The operands are constant indices to specify which value to extract
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3208in a similar manner as indices in a
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3209'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3210</p>
3211
3212<h5>Semantics:</h5>
3213
3214<p>
3215The result is the value at the position in the aggregate specified by
3216the index operands.
3217</p>
3218
3219<h5>Example:</h5>
3220
3221<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3222 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3223</pre>
3224</div>
3225
3226
3227<!-- _______________________________________________________________________ -->
3228<div class="doc_subsubsection">
3229 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3230</div>
3231
3232<div class="doc_text">
3233
3234<h5>Syntax:</h5>
3235
3236<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3237 &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]3238</pre>
3239
3240<h5>Overview:</h5>
3241
3242<p>
3243The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3244into a struct field or array element in an aggregate.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3245</p>
3246
3247
3248<h5>Arguments:</h5>
3249
3250<p>
3251The first operand of an '<tt>insertvalue</tt>' instruction is a
3252value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
3253The second operand is a first-class value to insert.
Dan Gohmanc4b49eb2008-05-23 21:53:15 +0000[diff] [blame]3254The following operands are constant indices
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3255indicating the position at which to insert the value in a similar manner as
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3256indices in a
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3257'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3258The value to insert must have the same type as the value identified
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3259by the indices.
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3260</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3261
3262<h5>Semantics:</h5>
3263
3264<p>
3265The result is an aggregate of the same type as <tt>val</tt>. Its
3266value is that of <tt>val</tt> except that the value at the position
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3267specified by the indices is that of <tt>elt</tt>.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3268</p>
3269
3270<h5>Example:</h5>
3271
3272<pre>
Dan Gohman52bb2db2008-06-23 15:26:37 +0000[diff] [blame]3273 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3274</pre>
3275</div>
3276
3277
3278<!-- ======================================================================= -->
3279<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3280 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]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 Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3285<p>A key design point of an SSA-based representation is how it
3286represents memory. In LLVM, no memory locations are in SSA form, which
3287makes things very simple. This section describes how to read, write,
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3288allocate, and free memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3289
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3290</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3291
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3292<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3293<div class="doc_subsubsection">
3294 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3295</div>
3296
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3297<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3298
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3299<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3300
3301<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3302 &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]3303</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3304
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3305<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3306
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3307<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]3308heap and returns a pointer to it. The object is always allocated in the generic
3309address space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3310
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3311<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3312
3313<p>The '<tt>malloc</tt>' instruction allocates
3314<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswell6e4ca612004-02-24 16:13:56 +0000[diff] [blame]3315bytes of memory from the operating system and returns a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3316appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3317number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3318If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3319be aligned to at least that boundary. If not specified, or if zero, the target can
3320choose to align the allocation on any convenient boundary.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3321
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3322<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3323
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3324<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3325
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3326<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewycky02ff3082008-11-24 03:41:24 +0000[diff] [blame]3327a pointer is returned. The result of a zero byte allocation is undefined. The
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3328result is null if there is insufficient memory available.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3329
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3330<h5>Example:</h5>
3331
3332<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3333 %array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3334
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3335 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3336 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3337 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3338 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3339 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3340</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]3341
3342<p>Note that the code generator does not yet respect the
3343 alignment value.</p>
3344
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3345</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3346
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3347<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3348<div class="doc_subsubsection">
3349 <a name="i_free">'<tt>free</tt>' Instruction</a>
3350</div>
3351
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3352<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3353
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3354<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3355
3356<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3357 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3358</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3359
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3360<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3361
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3362<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]3363memory heap to be reallocated in the future.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3364
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3365<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3366
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3367<p>'<tt>value</tt>' shall be a pointer value that points to a value
3368that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
3369instruction.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3370
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3371<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3372
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3373<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattnere0db56d2008-04-19 22:41:32 +0000[diff] [blame]3374after this instruction executes. If the pointer is null, the operation
3375is a noop.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3376
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3377<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3378
3379<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3380 %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]3381 free [4 x i8]* %array
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3382</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3383</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3384
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3385<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3386<div class="doc_subsubsection">
3387 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3388</div>
3389
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3390<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3391
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3392<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3393
3394<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3395 &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]3396</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3397
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3398<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3399
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3400<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
3401currently executing function, to be automatically released when this function
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]3402returns to its caller. The object is always allocated in the generic address
3403space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3404
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3405<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3406
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3407<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3408bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3409appropriate type to the program. If "NumElements" is specified, it is the
3410number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3411If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3412to be aligned to at least that boundary. If not specified, or if zero, the target
3413can choose to align the allocation on any convenient boundary.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3414
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3415<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3416
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3417<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3418
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3419<p>Memory is allocated; a pointer is returned. The operation is undefiend if
3420there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3421memory is automatically released when the function returns. The '<tt>alloca</tt>'
3422instruction is commonly used to represent automatic variables that must
3423have an address available. When the function returns (either with the <tt><a
John Criswelldae2e932005-05-12 16:55:34 +0000[diff] [blame]3424 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]3425instructions), the memory is reclaimed. Allocating zero bytes
3426is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3427
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3428<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3429
3430<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3431 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
3432 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3433 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
3434 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3435</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3436</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3437
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3438<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3439<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3440Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3441<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3442<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]3443<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]3444<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3445<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3446<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3447<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]3448address from which to load. The pointer must point to a <a
Chris Lattnere53e5082004-06-03 22:57:15 +0000[diff] [blame]3449 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]3450marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3451the number or order of execution of this <tt>load</tt> with other
3452volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3453instructions. </p>
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3454<p>
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3455The optional constant "align" argument specifies the alignment of the operation
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3456(that is, the alignment of the memory address). A value of 0 or an
3457omitted "align" argument means that the operation has the preferential
3458alignment for the target. It is the responsibility of the code emitter
3459to ensure that the alignment information is correct. Overestimating
3460the alignment results in an undefined behavior. Underestimating the
3461alignment may produce less efficient code. An alignment of 1 is always
3462safe.
3463</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3464<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3465<p>The location of memory pointed to is loaded.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3466<h5>Examples:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3467<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3468 <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3469 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
3470 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3471</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3472</div>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3473<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3474<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3475Instruction</a> </div>
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]3476<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3477<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]3478<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
3479 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]3480</pre>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3481<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3482<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3483<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3484<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3485to 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]3486operand must be a pointer to the <a href="#t_firstclass">first class</a> type
3487of the '<tt>&lt;value&gt;</tt>'
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]3488operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3489optimizer is not allowed to modify the number or order of execution of
3490this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
3491 href="#i_store">store</a></tt> instructions.</p>
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3492<p>
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3493The optional constant "align" argument specifies the alignment of the operation
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3494(that is, the alignment of the memory address). A value of 0 or an
3495omitted "align" argument means that the operation has the preferential
3496alignment for the target. It is the responsibility of the code emitter
3497to ensure that the alignment information is correct. Overestimating
3498the alignment results in an undefined behavior. Underestimating the
3499alignment may produce less efficient code. An alignment of 1 is always
3500safe.
3501</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3502<h5>Semantics:</h5>
3503<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
3504at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3505<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3506<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]3507 store i32 3, i32* %ptr <i>; yields {void}</i>
3508 %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]3509</pre>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3510</div>
3511
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3512<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3513<div class="doc_subsubsection">
3514 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3515</div>
3516
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3517<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3518<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3519<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3520 &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]3521</pre>
3522
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3523<h5>Overview:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3524
3525<p>
3526The '<tt>getelementptr</tt>' instruction is used to get the address of a
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3527subelement of an aggregate data structure. It performs address calculation only
3528and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3529
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3530<h5>Arguments:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3531
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3532<p>The first argument is always a pointer, and forms the basis of the
3533calculation. The remaining arguments are indices, that indicate which of the
3534elements of the aggregate object are indexed. The interpretation of each index
3535is dependent on the type being indexed into. The first index always indexes the
3536pointer value given as the first argument, the second index indexes a value of
3537the type pointed to (not necessarily the value directly pointed to, since the
3538first index can be non-zero), etc. The first type indexed into must be a pointer
3539value, subsequent types can be arrays, vectors and structs. Note that subsequent
3540types being indexed into can never be pointers, since that would require loading
3541the pointer before continuing calculation.</p>
3542
3543<p>The type of each index argument depends on the type it is indexing into.
3544When indexing into a (packed) structure, only <tt>i32</tt> integer
3545<b>constants</b> are allowed. When indexing into an array, pointer or vector,
3546only integers of 32 or 64 bits are allowed (also non-constants). 32-bit values
3547will be sign extended to 64-bits if required.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3548
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3549<p>For example, let's consider a C code fragment and how it gets
3550compiled to LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3551
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3552<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3553<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3554struct RT {
3555 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3556 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3557 char C;
3558};
3559struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3560 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3561 double Y;
3562 struct RT Z;
3563};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3564
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3565int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3566 return &amp;s[1].Z.B[5][13];
3567}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3568</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3569</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3570
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3571<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3572
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3573<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3574<pre>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]3575%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
3576%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3577
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3578define i32* %foo(%ST* %s) {
3579entry:
3580 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3581 ret i32* %reg
3582}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3583</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3584</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3585
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3586<h5>Semantics:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3587
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3588<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]3589type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3590}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3591the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3592i8 }</tt>' type, another structure. The third index indexes into the second
3593element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3594array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3595'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
3596to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3597
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3598<p>Note that it is perfectly legal to index partially through a
3599structure, returning a pointer to an inner element. Because of this,
3600the LLVM code for the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3601
3602<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3603 define i32* %foo(%ST* %s) {
3604 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3605 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3606 %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]3607 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3608 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
3609 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3610 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3611</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3612
3613<p>Note that it is undefined to access an array out of bounds: array and
3614pointer indexes must always be within the defined bounds of the array type.
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]3615The one exception for this rule is zero length arrays. These arrays are
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3616defined to be accessible as variable length arrays, which requires access
3617beyond the zero'th element.</p>
3618
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3619<p>The getelementptr instruction is often confusing. For some more insight
3620into how it works, see <a href="GetElementPtr.html">the getelementptr
3621FAQ</a>.</p>
3622
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3623<h5>Example:</h5>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3624
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3625<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3626 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3627 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
3628 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3629 %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]3630 <i>; yields i8*:eptr</i>
3631 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3632</pre>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3633</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3634
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3635<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3636<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3637</div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3638<div class="doc_text">
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3639<p>The instructions in this category are the conversion instructions (casting)
3640which all take a single operand and a type. They perform various bit conversions
3641on the operand.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3642</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3643
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3644<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3645<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3646 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
3647</div>
3648<div class="doc_text">
3649
3650<h5>Syntax:</h5>
3651<pre>
3652 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3653</pre>
3654
3655<h5>Overview:</h5>
3656<p>
3657The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
3658</p>
3659
3660<h5>Arguments:</h5>
3661<p>
3662The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
3663be 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]3664and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3665type. The bit size of <tt>value</tt> must be larger than the bit size of
3666<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3667
3668<h5>Semantics:</h5>
3669<p>
3670The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3671and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
3672larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
3673It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3674
3675<h5>Example:</h5>
3676<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3677 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3678 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
3679 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3680</pre>
3681</div>
3682
3683<!-- _______________________________________________________________________ -->
3684<div class="doc_subsubsection">
3685 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
3686</div>
3687<div class="doc_text">
3688
3689<h5>Syntax:</h5>
3690<pre>
3691 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3692</pre>
3693
3694<h5>Overview:</h5>
3695<p>The '<tt>zext</tt>' instruction zero extends its operand to type
3696<tt>ty2</tt>.</p>
3697
3698
3699<h5>Arguments:</h5>
3700<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]3701<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3702also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3703<tt>value</tt> must be smaller than the bit size of the destination type,
3704<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3705
3706<h5>Semantics:</h5>
3707<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]3708bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3709
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]3710<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]3711
3712<h5>Example:</h5>
3713<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3714 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3715 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3716</pre>
3717</div>
3718
3719<!-- _______________________________________________________________________ -->
3720<div class="doc_subsubsection">
3721 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3722</div>
3723<div class="doc_text">
3724
3725<h5>Syntax:</h5>
3726<pre>
3727 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3728</pre>
3729
3730<h5>Overview:</h5>
3731<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3732
3733<h5>Arguments:</h5>
3734<p>
3735The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3736<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3737also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3738<tt>value</tt> must be smaller than the bit size of the destination type,
3739<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3740
3741<h5>Semantics:</h5>
3742<p>
3743The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3744bit (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]3745the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3746
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3747<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]3748
3749<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3750<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3751 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3752 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3753</pre>
3754</div>
3755
3756<!-- _______________________________________________________________________ -->
3757<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3758 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3759</div>
3760
3761<div class="doc_text">
3762
3763<h5>Syntax:</h5>
3764
3765<pre>
3766 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3767</pre>
3768
3769<h5>Overview:</h5>
3770<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3771<tt>ty2</tt>.</p>
3772
3773
3774<h5>Arguments:</h5>
3775<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3776 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3777cast it to. The size of <tt>value</tt> must be larger than the size of
3778<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3779<i>no-op cast</i>.</p>
3780
3781<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3782<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3783<a href="#t_floating">floating point</a> type to a smaller
3784<a href="#t_floating">floating point</a> type. If the value cannot fit within
3785the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3786
3787<h5>Example:</h5>
3788<pre>
3789 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3790 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3791</pre>
3792</div>
3793
3794<!-- _______________________________________________________________________ -->
3795<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3796 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3797</div>
3798<div class="doc_text">
3799
3800<h5>Syntax:</h5>
3801<pre>
3802 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3803</pre>
3804
3805<h5>Overview:</h5>
3806<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3807floating point value.</p>
3808
3809<h5>Arguments:</h5>
3810<p>The '<tt>fpext</tt>' instruction takes a
3811<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3812and a <a href="#t_floating">floating point</a> type to cast it to. The source
3813type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3814
3815<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3816<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3817<a href="#t_floating">floating point</a> type to a larger
3818<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3819used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3820<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]3821
3822<h5>Example:</h5>
3823<pre>
3824 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3825 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3826</pre>
3827</div>
3828
3829<!-- _______________________________________________________________________ -->
3830<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]3831 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3832</div>
3833<div class="doc_text">
3834
3835<h5>Syntax:</h5>
3836<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3837 &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]3838</pre>
3839
3840<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3841<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3842unsigned integer equivalent of type <tt>ty2</tt>.
3843</p>
3844
3845<h5>Arguments:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3846<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]3847scalar or vector <a href="#t_floating">floating point</a> value, and a type
3848to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3849type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3850vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3851
3852<h5>Semantics:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3853<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3854<a href="#t_floating">floating point</a> operand into the nearest (rounding
3855towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3856the results are undefined.</p>
3857
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3858<h5>Example:</h5>
3859<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3860 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3861 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3862 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3863</pre>
3864</div>
3865
3866<!-- _______________________________________________________________________ -->
3867<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3868 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3869</div>
3870<div class="doc_text">
3871
3872<h5>Syntax:</h5>
3873<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3874 &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]3875</pre>
3876
3877<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3878<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3879<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]3880</p>
3881
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3882<h5>Arguments:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3883<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]3884scalar or vector <a href="#t_floating">floating point</a> value, and a type
3885to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3886type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3887vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3888
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3889<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3890<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3891<a href="#t_floating">floating point</a> operand into the nearest (rounding
3892towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3893the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3894
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3895<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3896<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3897 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3898 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3899 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3900</pre>
3901</div>
3902
3903<!-- _______________________________________________________________________ -->
3904<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3905 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3906</div>
3907<div class="doc_text">
3908
3909<h5>Syntax:</h5>
3910<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3911 &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]3912</pre>
3913
3914<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3915<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3916integer and converts that value to the <tt>ty2</tt> type.</p>
3917
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3918<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3919<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3920scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3921to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3922type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3923floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3924
3925<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3926<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3927integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3928the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3929
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3930<h5>Example:</h5>
3931<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3932 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3933 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3934</pre>
3935</div>
3936
3937<!-- _______________________________________________________________________ -->
3938<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3939 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3940</div>
3941<div class="doc_text">
3942
3943<h5>Syntax:</h5>
3944<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3945 &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]3946</pre>
3947
3948<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3949<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3950integer and converts that value to the <tt>ty2</tt> type.</p>
3951
3952<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3953<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3954scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3955to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3956type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3957floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3958
3959<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3960<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3961integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3962the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3963
3964<h5>Example:</h5>
3965<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3966 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3967 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3968</pre>
3969</div>
3970
3971<!-- _______________________________________________________________________ -->
3972<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3973 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3974</div>
3975<div class="doc_text">
3976
3977<h5>Syntax:</h5>
3978<pre>
3979 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3980</pre>
3981
3982<h5>Overview:</h5>
3983<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3984the integer type <tt>ty2</tt>.</p>
3985
3986<h5>Arguments:</h5>
3987<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3988must 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]3989<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]3990
3991<h5>Semantics:</h5>
3992<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3993<tt>ty2</tt> by interpreting the pointer value as an integer and either
3994truncating or zero extending that value to the size of the integer type. If
3995<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3996<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]3997are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3998change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3999
4000<h5>Example:</h5>
4001<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4002 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
4003 %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]4004</pre>
4005</div>
4006
4007<!-- _______________________________________________________________________ -->
4008<div class="doc_subsubsection">
4009 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
4010</div>
4011<div class="doc_text">
4012
4013<h5>Syntax:</h5>
4014<pre>
4015 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4016</pre>
4017
4018<h5>Overview:</h5>
4019<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
4020a pointer type, <tt>ty2</tt>.</p>
4021
4022<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4023<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4024value to cast, and a type to cast it to, which must be a
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4025<a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4026
4027<h5>Semantics:</h5>
4028<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
4029<tt>ty2</tt> by applying either a zero extension or a truncation depending on
4030the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
4031size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
4032the size of a pointer then a zero extension is done. If they are the same size,
4033nothing is done (<i>no-op cast</i>).</p>
4034
4035<h5>Example:</h5>
4036<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4037 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
4038 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
4039 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4040</pre>
4041</div>
4042
4043<!-- _______________________________________________________________________ -->
4044<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4045 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4046</div>
4047<div class="doc_text">
4048
4049<h5>Syntax:</h5>
4050<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4051 &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]4052</pre>
4053
4054<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4055
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4056<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4057<tt>ty2</tt> without changing any bits.</p>
4058
4059<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4060
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4061<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Dan Gohman500233a2008-09-08 16:45:59 +0000[diff] [blame]4062a non-aggregate first class value, and a type to cast it to, which must also be
4063a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
4064<tt>value</tt>
Reid Spencer19b569f2007-01-09 20:08:58 +0000[diff] [blame]4065and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4066type is a pointer, the destination type must also be a pointer. This
4067instruction supports bitwise conversion of vectors to integers and to vectors
4068of other types (as long as they have the same size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4069
4070<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4071<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4072<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
4073this conversion. The conversion is done as if the <tt>value</tt> had been
4074stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
4075converted to other pointer types with this instruction. To convert pointers to
4076other types, use the <a href="#i_inttoptr">inttoptr</a> or
4077<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4078
4079<h5>Example:</h5>
4080<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4081 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4082 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4083 %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]4084</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4085</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4086
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4087<!-- ======================================================================= -->
4088<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
4089<div class="doc_text">
4090<p>The instructions in this category are the "miscellaneous"
4091instructions, which defy better classification.</p>
4092</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4093
4094<!-- _______________________________________________________________________ -->
4095<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4096</div>
4097<div class="doc_text">
4098<h5>Syntax:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4099<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]4100</pre>
4101<h5>Overview:</h5>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4102<p>The '<tt>icmp</tt>' instruction returns a boolean value or
4103a vector of boolean values based on comparison
4104of its two integer, integer vector, or pointer operands.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4105<h5>Arguments:</h5>
4106<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4107the condition code indicating the kind of comparison to perform. It is not
4108a value, just a keyword. The possible condition code are:
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4109</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4110<ol>
4111 <li><tt>eq</tt>: equal</li>
4112 <li><tt>ne</tt>: not equal </li>
4113 <li><tt>ugt</tt>: unsigned greater than</li>
4114 <li><tt>uge</tt>: unsigned greater or equal</li>
4115 <li><tt>ult</tt>: unsigned less than</li>
4116 <li><tt>ule</tt>: unsigned less or equal</li>
4117 <li><tt>sgt</tt>: signed greater than</li>
4118 <li><tt>sge</tt>: signed greater or equal</li>
4119 <li><tt>slt</tt>: signed less than</li>
4120 <li><tt>sle</tt>: signed less or equal</li>
4121</ol>
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]4122<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4123<a href="#t_pointer">pointer</a>
4124or integer <a href="#t_vector">vector</a> typed.
4125They must also be identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4126<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4127<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]4128the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4129yields 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]4130</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4131<ol>
4132 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
4133 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
4134 </li>
4135 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4136 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4137 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4138 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4139 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4140 <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]4141 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4142 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4143 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4144 <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]4145 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4146 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4147 <li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4148 <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]4149 <li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4150 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4151 <li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4152 <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]4153</ol>
4154<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4155values are compared as if they were integers.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4156<p>If the operands are integer vectors, then they are compared
4157element by element. The result is an <tt>i1</tt> vector with
4158the same number of elements as the values being compared.
4159Otherwise, the result is an <tt>i1</tt>.
4160</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4161
4162<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4163<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
4164 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4165 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4166 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4167 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4168 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4169</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4170
4171<p>Note that the code generator does not yet support vector types with
4172 the <tt>icmp</tt> instruction.</p>
4173
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4174</div>
4175
4176<!-- _______________________________________________________________________ -->
4177<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4178</div>
4179<div class="doc_text">
4180<h5>Syntax:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4181<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]4182</pre>
4183<h5>Overview:</h5>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4184<p>The '<tt>fcmp</tt>' instruction returns a boolean value
4185or vector of boolean values based on comparison
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4186of its operands.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4187<p>
4188If the operands are floating point scalars, then the result
4189type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
4190</p>
4191<p>If the operands are floating point vectors, then the result type
4192is a vector of boolean with the same number of elements as the
4193operands being compared.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4194<h5>Arguments:</h5>
4195<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4196the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4197a value, just a keyword. The possible condition code are:</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4198<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4199 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4200 <li><tt>oeq</tt>: ordered and equal</li>
4201 <li><tt>ogt</tt>: ordered and greater than </li>
4202 <li><tt>oge</tt>: ordered and greater than or equal</li>
4203 <li><tt>olt</tt>: ordered and less than </li>
4204 <li><tt>ole</tt>: ordered and less than or equal</li>
4205 <li><tt>one</tt>: ordered and not equal</li>
4206 <li><tt>ord</tt>: ordered (no nans)</li>
4207 <li><tt>ueq</tt>: unordered or equal</li>
4208 <li><tt>ugt</tt>: unordered or greater than </li>
4209 <li><tt>uge</tt>: unordered or greater than or equal</li>
4210 <li><tt>ult</tt>: unordered or less than </li>
4211 <li><tt>ule</tt>: unordered or less than or equal</li>
4212 <li><tt>une</tt>: unordered or not equal</li>
4213 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4214 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4215</ol>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4216<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer93a49852006-12-06 07:08:07 +0000[diff] [blame]4217<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4218<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
4219either a <a href="#t_floating">floating point</a> type
4220or a <a href="#t_vector">vector</a> of floating point type.
4221They must have identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4222<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4223<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4224according to the condition code given as <tt>cond</tt>.
4225If the operands are vectors, then the vectors are compared
4226element by element.
4227Each comparison performed
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4228always yields an <a href="#t_primitive">i1</a> result, as follows:</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4229<ol>
4230 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4231 <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]4232 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4233 <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]4234 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4235 <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]4236 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4237 <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]4238 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4239 <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]4240 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4241 <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]4242 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4243 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
4244 <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]4245 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4246 <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]4247 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4248 <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]4249 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4250 <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]4251 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4252 <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]4253 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4254 <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]4255 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4256 <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]4257 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4258</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4259
4260<h5>Example:</h5>
4261<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]4262 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4263 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4264 &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]4265</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4266
4267<p>Note that the code generator does not yet support vector types with
4268 the <tt>fcmp</tt> instruction.</p>
4269
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4270</div>
4271
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4272<!-- _______________________________________________________________________ -->
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4273<div class="doc_subsubsection">
4274 <a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
4275</div>
4276<div class="doc_text">
4277<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4278<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]4279</pre>
4280<h5>Overview:</h5>
4281<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
4282element-wise comparison of its two integer vector operands.</p>
4283<h5>Arguments:</h5>
4284<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
4285the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4286a value, just a keyword. The possible condition code are:</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4287<ol>
4288 <li><tt>eq</tt>: equal</li>
4289 <li><tt>ne</tt>: not equal </li>
4290 <li><tt>ugt</tt>: unsigned greater than</li>
4291 <li><tt>uge</tt>: unsigned greater or equal</li>
4292 <li><tt>ult</tt>: unsigned less than</li>
4293 <li><tt>ule</tt>: unsigned less or equal</li>
4294 <li><tt>sgt</tt>: signed greater than</li>
4295 <li><tt>sge</tt>: signed greater or equal</li>
4296 <li><tt>slt</tt>: signed less than</li>
4297 <li><tt>sle</tt>: signed less or equal</li>
4298</ol>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4299<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4300<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
4301<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4302<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4303according to the condition code given as <tt>cond</tt>. The comparison yields a
4304<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
4305identical type as the values being compared. The most significant bit in each
4306element is 1 if the element-wise comparison evaluates to true, and is 0
4307otherwise. All other bits of the result are undefined. The condition codes
4308are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4309instruction</a>.</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4310
4311<h5>Example:</h5>
4312<pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4313 &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>
4314 &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]4315</pre>
4316</div>
4317
4318<!-- _______________________________________________________________________ -->
4319<div class="doc_subsubsection">
4320 <a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
4321</div>
4322<div class="doc_text">
4323<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4324<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]4325<h5>Overview:</h5>
4326<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
4327element-wise comparison of its two floating point vector operands. The output
4328elements have the same width as the input elements.</p>
4329<h5>Arguments:</h5>
4330<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
4331the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4332a value, just a keyword. The possible condition code are:</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4333<ol>
4334 <li><tt>false</tt>: no comparison, always returns false</li>
4335 <li><tt>oeq</tt>: ordered and equal</li>
4336 <li><tt>ogt</tt>: ordered and greater than </li>
4337 <li><tt>oge</tt>: ordered and greater than or equal</li>
4338 <li><tt>olt</tt>: ordered and less than </li>
4339 <li><tt>ole</tt>: ordered and less than or equal</li>
4340 <li><tt>one</tt>: ordered and not equal</li>
4341 <li><tt>ord</tt>: ordered (no nans)</li>
4342 <li><tt>ueq</tt>: unordered or equal</li>
4343 <li><tt>ugt</tt>: unordered or greater than </li>
4344 <li><tt>uge</tt>: unordered or greater than or equal</li>
4345 <li><tt>ult</tt>: unordered or less than </li>
4346 <li><tt>ule</tt>: unordered or less than or equal</li>
4347 <li><tt>une</tt>: unordered or not equal</li>
4348 <li><tt>uno</tt>: unordered (either nans)</li>
4349 <li><tt>true</tt>: no comparison, always returns true</li>
4350</ol>
4351<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
4352<a href="#t_floating">floating point</a> typed. They must also be identical
4353types.</p>
4354<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4355<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4356according to the condition code given as <tt>cond</tt>. The comparison yields a
4357<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
4358an identical number of elements as the values being compared, and each element
4359having identical with to the width of the floating point elements. The most
4360significant bit in each element is 1 if the element-wise comparison evaluates to
4361true, and is 0 otherwise. All other bits of the result are undefined. The
4362condition codes are evaluated identically to the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4363<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4364
4365<h5>Example:</h5>
4366<pre>
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]4367 <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0, i32 -1 &gt;</i>
4368 &lt;result&gt; = vfcmp oeq &lt;2 x float&gt; &lt; float 4, float 0 &gt;, &lt; float 5, float 0 &gt;
4369
4370 <i>; yields: result=&lt;2 x i64&gt; &lt; i64 -1, i64 0 &gt;</i>
4371 &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]4372</pre>
4373</div>
4374
4375<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4376<div class="doc_subsubsection">
4377 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4378</div>
4379
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4380<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4381
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4382<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4383
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4384<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
4385<h5>Overview:</h5>
4386<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
4387the SSA graph representing the function.</p>
4388<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4389
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4390<p>The type of the incoming values is specified with the first type
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4391field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
4392as arguments, with one pair for each predecessor basic block of the
4393current block. Only values of <a href="#t_firstclass">first class</a>
4394type may be used as the value arguments to the PHI node. Only labels
4395may be used as the label arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4396
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4397<p>There must be no non-phi instructions between the start of a basic
4398block and the PHI instructions: i.e. PHI instructions must be first in
4399a basic block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4400
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4401<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4402
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4403<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
4404specified by the pair corresponding to the predecessor basic block that executed
4405just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4406
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4407<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4408<pre>
4409Loop: ; Infinite loop that counts from 0 on up...
4410 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4411 %nextindvar = add i32 %indvar, 1
4412 br label %Loop
4413</pre>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4414</div>
4415
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4416<!-- _______________________________________________________________________ -->
4417<div class="doc_subsubsection">
4418 <a name="i_select">'<tt>select</tt>' Instruction</a>
4419</div>
4420
4421<div class="doc_text">
4422
4423<h5>Syntax:</h5>
4424
4425<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4426 &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>
4427
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4428 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4429</pre>
4430
4431<h5>Overview:</h5>
4432
4433<p>
4434The '<tt>select</tt>' instruction is used to choose one value based on a
4435condition, without branching.
4436</p>
4437
4438
4439<h5>Arguments:</h5>
4440
4441<p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4442The '<tt>select</tt>' instruction requires an 'i1' value or
4443a vector of 'i1' values indicating the
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4444condition, and two values of the same <a href="#t_firstclass">first class</a>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4445type. If the val1/val2 are vectors and
4446the condition is a scalar, then entire vectors are selected, not
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4447individual elements.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4448</p>
4449
4450<h5>Semantics:</h5>
4451
4452<p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4453If 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]4454value argument; otherwise, it returns the second value argument.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4455</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4456<p>
4457If the condition is a vector of i1, then the value arguments must
4458be vectors of the same size, and the selection is done element
4459by element.
4460</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4461
4462<h5>Example:</h5>
4463
4464<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4465 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4466</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4467
4468<p>Note that the code generator does not yet support conditions
4469 with vector type.</p>
4470
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4471</div>
4472
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]4473
4474<!-- _______________________________________________________________________ -->
4475<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4476 <a name="i_call">'<tt>call</tt>' Instruction</a>
4477</div>
4478
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4479<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4480
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4481<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4482<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]4483 &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]4484</pre>
4485
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4486<h5>Overview:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4487
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4488<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4489
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4490<h5>Arguments:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4491
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4492<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4493
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4494<ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4495 <li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4496 <p>The optional "tail" marker indicates whether the callee function accesses
4497 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4498 function call is eligible for tail call optimization. Note that calls may
4499 be marked "tail" even if they do not occur before a <a
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4500 href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4501 </li>
4502 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4503 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4504 convention</a> the call should use. If none is specified, the call defaults
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4505 to using C calling conventions.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4506 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4507
4508 <li>
4509 <p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4510 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
4511 and '<tt>inreg</tt>' attributes are valid here.</p>
4512 </li>
4513
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4514 <li>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4515 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
4516 the type of the return value. Functions that return no value are marked
4517 <tt><a href="#t_void">void</a></tt>.</p>
4518 </li>
4519 <li>
4520 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
4521 value being invoked. The argument types must match the types implied by
4522 this signature. This type can be omitted if the function is not varargs
4523 and if the function type does not return a pointer to a function.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4524 </li>
4525 <li>
4526 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4527 be invoked. In most cases, this is a direct function invocation, but
4528 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4529 to function value.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4530 </li>
4531 <li>
4532 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencera7e302a2005-05-01 22:22:57 +0000[diff] [blame]4533 function signature argument types. All arguments must be of
4534 <a href="#t_firstclass">first class</a> type. If the function signature
4535 indicates the function accepts a variable number of arguments, the extra
4536 arguments can be specified.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4537 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4538 <li>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]4539 <p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4540 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
4541 '<tt>readnone</tt>' attributes are valid here.</p>
4542 </li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4543</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4544
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4545<h5>Semantics:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4546
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4547<p>The '<tt>call</tt>' instruction is used to cause control flow to
4548transfer to a specified function, with its incoming arguments bound to
4549the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
4550instruction in the called function, control flow continues with the
4551instruction after the function call, and the return value of the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4552function is bound to the result argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4553
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4554<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4555
4556<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4557 %retval = call i32 @test(i32 %argc)
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]4558 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4559 %X = tail call i32 @foo() <i>; yields i32</i>
4560 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4561 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]4562
4563 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4564 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]4565 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
4566 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]4567 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]4568 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4569</pre>
4570
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4571</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4572
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4573<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4574<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]4575 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4576</div>
4577
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4578<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4579
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4580<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4581
4582<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4583 &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]4584</pre>
4585
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4586<h5>Overview:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4587
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4588<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4589the "variable argument" area of a function call. It is used to implement the
4590<tt>va_arg</tt> macro in C.</p>
4591
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4592<h5>Arguments:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4593
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4594<p>This instruction takes a <tt>va_list*</tt> value and the type of
4595the argument. It returns a value of the specified argument type and
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4596increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4597actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4598
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4599<h5>Semantics:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4600
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4601<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
4602type from the specified <tt>va_list</tt> and causes the
4603<tt>va_list</tt> to point to the next argument. For more information,
4604see the variable argument handling <a href="#int_varargs">Intrinsic
4605Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4606
4607<p>It is legal for this instruction to be called in a function which does not
4608take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4609function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4610
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4611<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4612href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4613argument.</p>
4614
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4615<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4616
4617<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4618
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]4619<p>Note that the code generator does not yet fully support va_arg
4620 on many targets. Also, it does not currently support va_arg with
4621 aggregate types on any target.</p>
4622
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4623</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4624
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4625<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4626<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4627<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4628
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4629<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4630
4631<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4632well known names and semantics and are required to follow certain restrictions.
4633Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4634language that does not require changing all of the transformations in LLVM when
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]4635adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4636
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4637<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4638prefix is reserved in LLVM for intrinsic names; thus, function names may not
4639begin with this prefix. Intrinsic functions must always be external functions:
4640you cannot define the body of intrinsic functions. Intrinsic functions may
4641only be used in call or invoke instructions: it is illegal to take the address
4642of an intrinsic function. Additionally, because intrinsic functions are part
4643of the LLVM language, it is required if any are added that they be documented
4644here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4645
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4646<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
4647a family of functions that perform the same operation but on different data
4648types. Because LLVM can represent over 8 million different integer types,
4649overloading is used commonly to allow an intrinsic function to operate on any
4650integer type. One or more of the argument types or the result type can be
4651overloaded to accept any integer type. Argument types may also be defined as
4652exactly matching a previous argument's type or the result type. This allows an
4653intrinsic function which accepts multiple arguments, but needs all of them to
4654be of the same type, to only be overloaded with respect to a single argument or
4655the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4656
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4657<p>Overloaded intrinsics will have the names of its overloaded argument types
4658encoded into its function name, each preceded by a period. Only those types
4659which are overloaded result in a name suffix. Arguments whose type is matched
4660against another type do not. For example, the <tt>llvm.ctpop</tt> function can
4661take an integer of any width and returns an integer of exactly the same integer
4662width. This leads to a family of functions such as
4663<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
4664Only one type, the return type, is overloaded, and only one type suffix is
4665required. Because the argument's type is matched against the return type, it
4666does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4667
4668<p>To learn how to add an intrinsic function, please see the
4669<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4670</p>
4671
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4672</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4673
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4674<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4675<div class="doc_subsection">
4676 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
4677</div>
4678
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4679<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4680
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4681<p>Variable argument support is defined in LLVM with the <a
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]4682 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4683intrinsic functions. These functions are related to the similarly
4684named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4685
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4686<p>All of these functions operate on arguments that use a
4687target-specific value type "<tt>va_list</tt>". The LLVM assembly
4688language reference manual does not define what this type is, so all
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4689transformations should be prepared to handle these functions regardless of
4690the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4691
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]4692<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]4693instruction and the variable argument handling intrinsic functions are
4694used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4695
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4696<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4697<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4698define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4699 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4700 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4701 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4702 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4703
4704 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4705 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4706
4707 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4708 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4709 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4710 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4711 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4712
4713 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4714 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4715 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4716}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4717
4718declare void @llvm.va_start(i8*)
4719declare void @llvm.va_copy(i8*, i8*)
4720declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4721</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4722</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4723
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4724</div>
4725
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4726<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4727<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4728 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4729</div>
4730
4731
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4732<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4733<h5>Syntax:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4734<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4735<h5>Overview:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4736<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4737<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
4738href="#i_va_arg">va_arg</a></tt>.</p>
4739
4740<h5>Arguments:</h5>
4741
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4742<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]4743
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4744<h5>Semantics:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4745
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4746<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]4747macro available in C. In a target-dependent way, it initializes the
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4748<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]4749<tt>va_arg</tt> will produce the first variable argument passed to the function.
4750Unlike 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]4751last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4752
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4753</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4754
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4755<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4756<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4757 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4758</div>
4759
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4760<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4761<h5>Syntax:</h5>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4762<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4763<h5>Overview:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4764
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4765<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4766which 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]4767or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4768
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4769<h5>Arguments:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4770
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4771<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]4772
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4773<h5>Semantics:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4774
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4775<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]4776macro available in C. In a target-dependent way, it destroys the
4777<tt>va_list</tt> element to which the argument points. Calls to <a
4778href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
4779<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
4780<tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4781
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4782</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4783
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4784<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4785<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4786 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4787</div>
4788
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4789<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4790
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4791<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4792
4793<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4794 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4795</pre>
4796
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4797<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4798
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4799<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
4800from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4801
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4802<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4803
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4804<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]4805The 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]4806
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4807
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4808<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4809
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4810<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
4811macro available in C. In a target-dependent way, it copies the source
4812<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
4813intrinsic is necessary because the <tt><a href="#int_va_start">
4814llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
4815example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4816
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4817</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4818
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4819<!-- ======================================================================= -->
4820<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4821 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
4822</div>
4823
4824<div class="doc_text">
4825
4826<p>
4827LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]4828Collection</a> (GC) requires the implementation and generation of these
4829intrinsics.
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4830These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4831stack</a>, as well as garbage collector implementations that require <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4832href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4833Front-ends for type-safe garbage collected languages should generate these
4834intrinsics to make use of the LLVM garbage collectors. For more details, see <a
4835href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
4836</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]4837
4838<p>The garbage collection intrinsics only operate on objects in the generic
4839 address space (address space zero).</p>
4840
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4841</div>
4842
4843<!-- _______________________________________________________________________ -->
4844<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4845 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4846</div>
4847
4848<div class="doc_text">
4849
4850<h5>Syntax:</h5>
4851
4852<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4853 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4854</pre>
4855
4856<h5>Overview:</h5>
4857
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]4858<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]4859the code generator, and allows some metadata to be associated with it.</p>
4860
4861<h5>Arguments:</h5>
4862
4863<p>The first argument specifies the address of a stack object that contains the
4864root pointer. The second pointer (which must be either a constant or a global
4865value address) contains the meta-data to be associated with the root.</p>
4866
4867<h5>Semantics:</h5>
4868
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]4869<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]4870location. At compile-time, the code generator generates information to allow
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4871the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
4872intrinsic may only be used in a function which <a href="#gc">specifies a GC
4873algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4874
4875</div>
4876
4877
4878<!-- _______________________________________________________________________ -->
4879<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4880 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4881</div>
4882
4883<div class="doc_text">
4884
4885<h5>Syntax:</h5>
4886
4887<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4888 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4889</pre>
4890
4891<h5>Overview:</h5>
4892
4893<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4894locations, allowing garbage collector implementations that require read
4895barriers.</p>
4896
4897<h5>Arguments:</h5>
4898
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4899<p>The second argument is the address to read from, which should be an address
4900allocated from the garbage collector. The first object is a pointer to the
4901start of the referenced object, if needed by the language runtime (otherwise
4902null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4903
4904<h5>Semantics:</h5>
4905
4906<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4907instruction, but may be replaced with substantially more complex code by the
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4908garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
4909may only be used in a function which <a href="#gc">specifies a GC
4910algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4911
4912</div>
4913
4914
4915<!-- _______________________________________________________________________ -->
4916<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4917 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4918</div>
4919
4920<div class="doc_text">
4921
4922<h5>Syntax:</h5>
4923
4924<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4925 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4926</pre>
4927
4928<h5>Overview:</h5>
4929
4930<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4931locations, allowing garbage collector implementations that require write
4932barriers (such as generational or reference counting collectors).</p>
4933
4934<h5>Arguments:</h5>
4935
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4936<p>The first argument is the reference to store, the second is the start of the
4937object to store it to, and the third is the address of the field of Obj to
4938store to. If the runtime does not require a pointer to the object, Obj may be
4939null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4940
4941<h5>Semantics:</h5>
4942
4943<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4944instruction, but may be replaced with substantially more complex code by the
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4945garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
4946may only be used in a function which <a href="#gc">specifies a GC
4947algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4948
4949</div>
4950
4951
4952
4953<!-- ======================================================================= -->
4954<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4955 <a name="int_codegen">Code Generator Intrinsics</a>
4956</div>
4957
4958<div class="doc_text">
4959<p>
4960These intrinsics are provided by LLVM to expose special features that may only
4961be implemented with code generator support.
4962</p>
4963
4964</div>
4965
4966<!-- _______________________________________________________________________ -->
4967<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4968 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4969</div>
4970
4971<div class="doc_text">
4972
4973<h5>Syntax:</h5>
4974<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4975 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4976</pre>
4977
4978<h5>Overview:</h5>
4979
4980<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4981The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4982target-specific value indicating the return address of the current function
4983or one of its callers.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4984</p>
4985
4986<h5>Arguments:</h5>
4987
4988<p>
4989The argument to this intrinsic indicates which function to return the address
4990for. Zero indicates the calling function, one indicates its caller, etc. The
4991argument is <b>required</b> to be a constant integer value.
4992</p>
4993
4994<h5>Semantics:</h5>
4995
4996<p>
4997The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4998the return address of the specified call frame, or zero if it cannot be
4999identified. The value returned by this intrinsic is likely to be incorrect or 0
5000for arguments other than zero, so it should only be used for debugging purposes.
5001</p>
5002
5003<p>
5004Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]5005aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5006source-language caller.
5007</p>
5008</div>
5009
5010
5011<!-- _______________________________________________________________________ -->
5012<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5013 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5014</div>
5015
5016<div class="doc_text">
5017
5018<h5>Syntax:</h5>
5019<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5020 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5021</pre>
5022
5023<h5>Overview:</h5>
5024
5025<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]5026The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5027target-specific frame pointer value for the specified stack frame.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5028</p>
5029
5030<h5>Arguments:</h5>
5031
5032<p>
5033The argument to this intrinsic indicates which function to return the frame
5034pointer for. Zero indicates the calling function, one indicates its caller,
5035etc. The argument is <b>required</b> to be a constant integer value.
5036</p>
5037
5038<h5>Semantics:</h5>
5039
5040<p>
5041The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
5042the frame address of the specified call frame, or zero if it cannot be
5043identified. The value returned by this intrinsic is likely to be incorrect or 0
5044for arguments other than zero, so it should only be used for debugging purposes.
5045</p>
5046
5047<p>
5048Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]5049aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5050source-language caller.
5051</p>
5052</div>
5053
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5054<!-- _______________________________________________________________________ -->
5055<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5056 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5057</div>
5058
5059<div class="doc_text">
5060
5061<h5>Syntax:</h5>
5062<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5063 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5064</pre>
5065
5066<h5>Overview:</h5>
5067
5068<p>
5069The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5070the function stack, for use with <a href="#int_stackrestore">
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5071<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
5072features like scoped automatic variable sized arrays in C99.
5073</p>
5074
5075<h5>Semantics:</h5>
5076
5077<p>
5078This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5079href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5080<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
5081<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
5082state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
5083practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
5084that were allocated after the <tt>llvm.stacksave</tt> was executed.
5085</p>
5086
5087</div>
5088
5089<!-- _______________________________________________________________________ -->
5090<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5091 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5092</div>
5093
5094<div class="doc_text">
5095
5096<h5>Syntax:</h5>
5097<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5098 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5099</pre>
5100
5101<h5>Overview:</h5>
5102
5103<p>
5104The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5105the function stack to the state it was in when the corresponding <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5106href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5107useful for implementing language features like scoped automatic variable sized
5108arrays in C99.
5109</p>
5110
5111<h5>Semantics:</h5>
5112
5113<p>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5114See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5115</p>
5116
5117</div>
5118
5119
5120<!-- _______________________________________________________________________ -->
5121<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5122 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5123</div>
5124
5125<div class="doc_text">
5126
5127<h5>Syntax:</h5>
5128<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5129 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]5130</pre>
5131
5132<h5>Overview:</h5>
5133
5134
5135<p>
5136The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5137a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
5138no
5139effect on the behavior of the program but can change its performance
Chris Lattner2a615362005-02-28 19:47:14 +0000[diff] [blame]5140characteristics.
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5141</p>
5142
5143<h5>Arguments:</h5>
5144
5145<p>
5146<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
5147determining if the fetch should be for a read (0) or write (1), and
5148<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattneraeffb4a2005-03-07 20:31:38 +0000[diff] [blame]5149locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5150<tt>locality</tt> arguments must be constant integers.
5151</p>
5152
5153<h5>Semantics:</h5>
5154
5155<p>
5156This intrinsic does not modify the behavior of the program. In particular,
5157prefetches cannot trap and do not produce a value. On targets that support this
5158intrinsic, the prefetch can provide hints to the processor cache for better
5159performance.
5160</p>
5161
5162</div>
5163
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5164<!-- _______________________________________________________________________ -->
5165<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5166 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5167</div>
5168
5169<div class="doc_text">
5170
5171<h5>Syntax:</h5>
5172<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5173 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5174</pre>
5175
5176<h5>Overview:</h5>
5177
5178
5179<p>
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5180The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5181(PC) in a region of
5182code to simulators and other tools. The method is target specific, but it is
5183expected that the marker will use exported symbols to transmit the PC of the
5184marker.
5185The marker makes no guarantees that it will remain with any specific instruction
5186after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb3e7afd2006-03-24 07:16:10 +0000[diff] [blame]5187optimizations. The intended use is to be inserted after optimizations to allow
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5188correlations of simulation runs.
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5189</p>
5190
5191<h5>Arguments:</h5>
5192
5193<p>
5194<tt>id</tt> is a numerical id identifying the marker.
5195</p>
5196
5197<h5>Semantics:</h5>
5198
5199<p>
5200This intrinsic does not modify the behavior of the program. Backends that do not
5201support this intrinisic may ignore it.
5202</p>
5203
5204</div>
5205
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5206<!-- _______________________________________________________________________ -->
5207<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5208 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5209</div>
5210
5211<div class="doc_text">
5212
5213<h5>Syntax:</h5>
5214<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5215 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5216</pre>
5217
5218<h5>Overview:</h5>
5219
5220
5221<p>
5222The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5223counter register (or similar low latency, high accuracy clocks) on those targets
5224that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
5225As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
5226should only be used for small timings.
5227</p>
5228
5229<h5>Semantics:</h5>
5230
5231<p>
5232When directly supported, reading the cycle counter should not modify any memory.
5233Implementations are allowed to either return a application specific value or a
5234system wide value. On backends without support, this is lowered to a constant 0.
5235</p>
5236
5237</div>
5238
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5239<!-- ======================================================================= -->
5240<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5241 <a name="int_libc">Standard C Library Intrinsics</a>
5242</div>
5243
5244<div class="doc_text">
5245<p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5246LLVM provides intrinsics for a few important standard C library functions.
5247These intrinsics allow source-language front-ends to pass information about the
5248alignment of the pointer arguments to the code generator, providing opportunity
5249for more efficient code generation.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5250</p>
5251
5252</div>
5253
5254<!-- _______________________________________________________________________ -->
5255<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5256 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5257</div>
5258
5259<div class="doc_text">
5260
5261<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5262<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
5263width. Not all targets support all bit widths however.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5264<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5265 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5266 i8 &lt;len&gt;, i32 &lt;align&gt;)
5267 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5268 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5269 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5270 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5271 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5272 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5273</pre>
5274
5275<h5>Overview:</h5>
5276
5277<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5278The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5279location to the destination location.
5280</p>
5281
5282<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5283Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5284intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5285</p>
5286
5287<h5>Arguments:</h5>
5288
5289<p>
5290The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5291the source. The third argument is an integer argument
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5292specifying the number of bytes to copy, and the fourth argument is the alignment
5293of the source and destination locations.
5294</p>
5295
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5296<p>
5297If 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]5298the caller guarantees that both the source and destination pointers are aligned
5299to that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5300</p>
5301
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5302<h5>Semantics:</h5>
5303
5304<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5305The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5306location to the destination location, which are not allowed to overlap. It
5307copies "len" bytes of memory over. If the argument is known to be aligned to
5308some boundary, this can be specified as the fourth argument, otherwise it should
5309be set to 0 or 1.
5310</p>
5311</div>
5312
5313
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5314<!-- _______________________________________________________________________ -->
5315<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5316 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5317</div>
5318
5319<div class="doc_text">
5320
5321<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5322<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
5323width. Not all targets support all bit widths however.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5324<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5325 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5326 i8 &lt;len&gt;, i32 &lt;align&gt;)
5327 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5328 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5329 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5330 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5331 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5332 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5333</pre>
5334
5335<h5>Overview:</h5>
5336
5337<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5338The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
5339location to the destination location. It is similar to the
Chris Lattner4b2cbcf2008-01-06 19:51:52 +0000[diff] [blame]5340'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5341</p>
5342
5343<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5344Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5345intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5346</p>
5347
5348<h5>Arguments:</h5>
5349
5350<p>
5351The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5352the source. The third argument is an integer argument
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5353specifying the number of bytes to copy, and the fourth argument is the alignment
5354of the source and destination locations.
5355</p>
5356
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5357<p>
5358If 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]5359the caller guarantees that the source and destination pointers are aligned to
5360that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5361</p>
5362
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5363<h5>Semantics:</h5>
5364
5365<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5366The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5367location to the destination location, which may overlap. It
5368copies "len" bytes of memory over. If the argument is known to be aligned to
5369some boundary, this can be specified as the fourth argument, otherwise it should
5370be set to 0 or 1.
5371</p>
5372</div>
5373
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5374
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5375<!-- _______________________________________________________________________ -->
5376<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5377 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5378</div>
5379
5380<div class="doc_text">
5381
5382<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5383<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
5384width. Not all targets support all bit widths however.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5385<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5386 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5387 i8 &lt;len&gt;, i32 &lt;align&gt;)
5388 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5389 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5390 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5391 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5392 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5393 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5394</pre>
5395
5396<h5>Overview:</h5>
5397
5398<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5399The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5400byte value.
5401</p>
5402
5403<p>
5404Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
5405does not return a value, and takes an extra alignment argument.
5406</p>
5407
5408<h5>Arguments:</h5>
5409
5410<p>
5411The first argument is a pointer to the destination to fill, the second is the
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5412byte value to fill it with, the third argument is an integer
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5413argument specifying the number of bytes to fill, and the fourth argument is the
5414known alignment of destination location.
5415</p>
5416
5417<p>
5418If 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]5419the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5420</p>
5421
5422<h5>Semantics:</h5>
5423
5424<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5425The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
5426the
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5427destination location. If the argument is known to be aligned to some boundary,
5428this can be specified as the fourth argument, otherwise it should be set to 0 or
54291.
5430</p>
5431</div>
5432
5433
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5434<!-- _______________________________________________________________________ -->
5435<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5436 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5437</div>
5438
5439<div class="doc_text">
5440
5441<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5442<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]5443floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5444types however.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5445<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5446 declare float @llvm.sqrt.f32(float %Val)
5447 declare double @llvm.sqrt.f64(double %Val)
5448 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5449 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5450 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5451</pre>
5452
5453<h5>Overview:</h5>
5454
5455<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5456The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5457returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5458<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner103e2d72008-01-29 07:00:44 +0000[diff] [blame]5459negative numbers other than -0.0 (which allows for better optimization, because
5460there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
5461defined to return -0.0 like IEEE sqrt.
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5462</p>
5463
5464<h5>Arguments:</h5>
5465
5466<p>
5467The argument and return value are floating point numbers of the same type.
5468</p>
5469
5470<h5>Semantics:</h5>
5471
5472<p>
Dan Gohmand6257fe2007-07-16 14:37:41 +0000[diff] [blame]5473This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5474floating point number.
5475</p>
5476</div>
5477
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5478<!-- _______________________________________________________________________ -->
5479<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5480 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5481</div>
5482
5483<div class="doc_text">
5484
5485<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5486<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]5487floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5488types however.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5489<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5490 declare float @llvm.powi.f32(float %Val, i32 %power)
5491 declare double @llvm.powi.f64(double %Val, i32 %power)
5492 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5493 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5494 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5495</pre>
5496
5497<h5>Overview:</h5>
5498
5499<p>
5500The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5501specified (positive or negative) power. The order of evaluation of
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5502multiplications is not defined. When a vector of floating point type is
5503used, the second argument remains a scalar integer value.
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5504</p>
5505
5506<h5>Arguments:</h5>
5507
5508<p>
5509The second argument is an integer power, and the first is a value to raise to
5510that power.
5511</p>
5512
5513<h5>Semantics:</h5>
5514
5515<p>
5516This function returns the first value raised to the second power with an
5517unspecified sequence of rounding operations.</p>
5518</div>
5519
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5520<!-- _______________________________________________________________________ -->
5521<div class="doc_subsubsection">
5522 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5523</div>
5524
5525<div class="doc_text">
5526
5527<h5>Syntax:</h5>
5528<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5529floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5530types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5531<pre>
5532 declare float @llvm.sin.f32(float %Val)
5533 declare double @llvm.sin.f64(double %Val)
5534 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5535 declare fp128 @llvm.sin.f128(fp128 %Val)
5536 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5537</pre>
5538
5539<h5>Overview:</h5>
5540
5541<p>
5542The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
5543</p>
5544
5545<h5>Arguments:</h5>
5546
5547<p>
5548The argument and return value are floating point numbers of the same type.
5549</p>
5550
5551<h5>Semantics:</h5>
5552
5553<p>
5554This function returns the sine of the specified operand, returning the
5555same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5556conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5557</div>
5558
5559<!-- _______________________________________________________________________ -->
5560<div class="doc_subsubsection">
5561 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5562</div>
5563
5564<div class="doc_text">
5565
5566<h5>Syntax:</h5>
5567<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5568floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5569types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5570<pre>
5571 declare float @llvm.cos.f32(float %Val)
5572 declare double @llvm.cos.f64(double %Val)
5573 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5574 declare fp128 @llvm.cos.f128(fp128 %Val)
5575 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5576</pre>
5577
5578<h5>Overview:</h5>
5579
5580<p>
5581The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
5582</p>
5583
5584<h5>Arguments:</h5>
5585
5586<p>
5587The argument and return value are floating point numbers of the same type.
5588</p>
5589
5590<h5>Semantics:</h5>
5591
5592<p>
5593This function returns the cosine of the specified operand, returning the
5594same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5595conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5596</div>
5597
5598<!-- _______________________________________________________________________ -->
5599<div class="doc_subsubsection">
5600 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5601</div>
5602
5603<div class="doc_text">
5604
5605<h5>Syntax:</h5>
5606<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5607floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5608types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5609<pre>
5610 declare float @llvm.pow.f32(float %Val, float %Power)
5611 declare double @llvm.pow.f64(double %Val, double %Power)
5612 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5613 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5614 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5615</pre>
5616
5617<h5>Overview:</h5>
5618
5619<p>
5620The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5621specified (positive or negative) power.
5622</p>
5623
5624<h5>Arguments:</h5>
5625
5626<p>
5627The second argument is a floating point power, and the first is a value to
5628raise to that power.
5629</p>
5630
5631<h5>Semantics:</h5>
5632
5633<p>
5634This function returns the first value raised to the second power,
5635returning the
5636same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5637conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5638</div>
5639
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5640
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5641<!-- ======================================================================= -->
5642<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5643 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5644</div>
5645
5646<div class="doc_text">
5647<p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5648LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5649These allow efficient code generation for some algorithms.
5650</p>
5651
5652</div>
5653
5654<!-- _______________________________________________________________________ -->
5655<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5656 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5657</div>
5658
5659<div class="doc_text">
5660
5661<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5662<p>This is an overloaded intrinsic function. You can use bswap on any integer
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5663type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5664<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5665 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5666 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5667 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5668</pre>
5669
5670<h5>Overview:</h5>
5671
5672<p>
Reid Spencer338ea092007-04-02 02:25:19 +0000[diff] [blame]5673The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5674values with an even number of bytes (positive multiple of 16 bits). These are
5675useful for performing operations on data that is not in the target's native
5676byte order.
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5677</p>
5678
5679<h5>Semantics:</h5>
5680
5681<p>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5682The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5683and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
5684intrinsic returns an i32 value that has the four bytes of the input i32
5685swapped, 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]5686i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
5687<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5688additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5689</p>
5690
5691</div>
5692
5693<!-- _______________________________________________________________________ -->
5694<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5695 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5696</div>
5697
5698<div class="doc_text">
5699
5700<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5701<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5702width. Not all targets support all bit widths however.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5703<pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5704 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5705 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5706 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5707 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5708 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5709</pre>
5710
5711<h5>Overview:</h5>
5712
5713<p>
Chris Lattnerec6cb612006-01-16 22:38:59 +0000[diff] [blame]5714The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
5715value.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5716</p>
5717
5718<h5>Arguments:</h5>
5719
5720<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]5721The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5722integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5723</p>
5724
5725<h5>Semantics:</h5>
5726
5727<p>
5728The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
5729</p>
5730</div>
5731
5732<!-- _______________________________________________________________________ -->
5733<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5734 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5735</div>
5736
5737<div class="doc_text">
5738
5739<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5740<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5741integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5742<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5743 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5744 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5745 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5746 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5747 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5748</pre>
5749
5750<h5>Overview:</h5>
5751
5752<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5753The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5754leading zeros in a variable.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5755</p>
5756
5757<h5>Arguments:</h5>
5758
5759<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]5760The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5761integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5762</p>
5763
5764<h5>Semantics:</h5>
5765
5766<p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5767The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
5768in 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]5769of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5770</p>
5771</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5772
5773
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5774
5775<!-- _______________________________________________________________________ -->
5776<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5777 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5778</div>
5779
5780<div class="doc_text">
5781
5782<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5783<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]5784integer bit width. Not all targets support all bit widths however.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5785<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5786 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5787 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5788 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5789 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5790 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5791</pre>
5792
5793<h5>Overview:</h5>
5794
5795<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5796The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5797trailing zeros.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5798</p>
5799
5800<h5>Arguments:</h5>
5801
5802<p>
5803The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5804integer type. The return type must match the argument type.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5805</p>
5806
5807<h5>Semantics:</h5>
5808
5809<p>
5810The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
5811in a variable. If the src == 0 then the result is the size in bits of the type
5812of src. For example, <tt>llvm.cttz(2) = 1</tt>.
5813</p>
5814</div>
5815
Reid Spencer497d93e2007-04-01 08:27:01 +0000[diff] [blame]5816<!-- _______________________________________________________________________ -->
5817<div class="doc_subsubsection">
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5818 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5819</div>
5820
5821<div class="doc_text">
5822
5823<h5>Syntax:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5824<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5825on any integer bit width.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5826<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5827 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
5828 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5829</pre>
5830
5831<h5>Overview:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5832<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5833range of bits from an integer value and returns them in the same bit width as
5834the original value.</p>
5835
5836<h5>Arguments:</h5>
5837<p>The first argument, <tt>%val</tt> and the result may be integer types of
5838any bit width but they must have the same bit width. The second and third
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5839arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5840
5841<h5>Semantics:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5842<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5843of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
5844<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
5845operates in forward mode.</p>
5846<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
5847right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5848only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
5849<ol>
5850 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
5851 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
5852 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
5853 to determine the number of bits to retain.</li>
5854 <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]5855 <li>The mask is ANDed with <tt>%val</tt> to produce the result.</li>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5856</ol>
Reid Spencerd6a85b52007-05-14 16:14:57 +0000[diff] [blame]5857<p>In reverse mode, a similar computation is made except that the bits are
5858returned in the reverse order. So, for example, if <tt>X</tt> has the value
5859<tt>i16 0x0ACF (101011001111)</tt> and we apply
5860<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
5861<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5862</div>
5863
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5864<div class="doc_subsubsection">
5865 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
5866</div>
5867
5868<div class="doc_text">
5869
5870<h5>Syntax:</h5>
5871<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5872on any integer bit width.</p>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5873<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5874 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
5875 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]5876</pre>
5877
5878<h5>Overview:</h5>
5879<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
5880of bits in an integer value with another integer value. It returns the integer
5881with the replaced bits.</p>
5882
5883<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5884<p>The first argument, <tt>%val</tt>, and the result may be integer types of
5885any bit width, but they must have the same bit width. <tt>%val</tt> is the value
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5886whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
5887integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
5888type since they specify only a bit index.</p>
5889
5890<h5>Semantics:</h5>
5891<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
5892of operation: forwards and reverse. If <tt>%lo</tt> is greater than
5893<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
5894operates in forward mode.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5895
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5896<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
5897truncating it down to the size of the replacement area or zero extending it
5898up to that size.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5899
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5900<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5901are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5902in <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]5903to the <tt>%hi</tt>th bit.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5904
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5905<p>In reverse mode, a similar computation is made except that the bits are
5906reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5907<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5908
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5909<h5>Examples:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5910
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5911<pre>
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5912 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5913 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5914 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5915 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5916 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]5917</pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5918
5919</div>
5920
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5921<!-- ======================================================================= -->
5922<div class="doc_subsection">
5923 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
5924</div>
5925
5926<div class="doc_text">
5927<p>
5928LLVM provides intrinsics for some arithmetic with overflow operations.
5929</p>
5930
5931</div>
5932
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5933<!-- _______________________________________________________________________ -->
5934<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5935 <a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5936</div>
5937
5938<div class="doc_text">
5939
5940<h5>Syntax:</h5>
5941
5942<p>This is an overloaded intrinsic. You can use <tt>llvm.sadd.with.overflow</tt>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5943on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5944
5945<pre>
5946 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
5947 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
5948 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
5949</pre>
5950
5951<h5>Overview:</h5>
5952
5953<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
5954a signed addition of the two arguments, and indicate whether an overflow
5955occurred during the signed summation.</p>
5956
5957<h5>Arguments:</h5>
5958
5959<p>The arguments (%a and %b) and the first element of the result structure may
5960be of integer types of any bit width, but they must have the same bit width. The
5961second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
5962and <tt>%b</tt> are the two values that will undergo signed addition.</p>
5963
5964<h5>Semantics:</h5>
5965
5966<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
5967a signed addition of the two variables. They return a structure &mdash; the
5968first element of which is the signed summation, and the second element of which
5969is a bit specifying if the signed summation resulted in an overflow.</p>
5970
5971<h5>Examples:</h5>
5972<pre>
5973 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
5974 %sum = extractvalue {i32, i1} %res, 0
5975 %obit = extractvalue {i32, i1} %res, 1
5976 br i1 %obit, label %overflow, label %normal
5977</pre>
5978
5979</div>
5980
5981<!-- _______________________________________________________________________ -->
5982<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5983 <a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5984</div>
5985
5986<div class="doc_text">
5987
5988<h5>Syntax:</h5>
5989
5990<p>This is an overloaded intrinsic. You can use <tt>llvm.uadd.with.overflow</tt>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5991on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5992
5993<pre>
5994 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
5995 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
5996 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
5997</pre>
5998
5999<h5>Overview:</h5>
6000
6001<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
6002an unsigned addition of the two arguments, and indicate whether a carry occurred
6003during the unsigned summation.</p>
6004
6005<h5>Arguments:</h5>
6006
6007<p>The arguments (%a and %b) and the first element of the result structure may
6008be of integer types of any bit width, but they must have the same bit width. The
6009second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
6010and <tt>%b</tt> are the two values that will undergo unsigned addition.</p>
6011
6012<h5>Semantics:</h5>
6013
6014<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
6015an unsigned addition of the two arguments. They return a structure &mdash; the
6016first element of which is the sum, and the second element of which is a bit
6017specifying if the unsigned summation resulted in a carry.</p>
6018
6019<h5>Examples:</h5>
6020<pre>
6021 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6022 %sum = extractvalue {i32, i1} %res, 0
6023 %obit = extractvalue {i32, i1} %res, 1
6024 br i1 %obit, label %carry, label %normal
6025</pre>
6026
6027</div>
6028
6029<!-- _______________________________________________________________________ -->
6030<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6031 <a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6032</div>
6033
6034<div class="doc_text">
6035
6036<h5>Syntax:</h5>
6037
6038<p>This is an overloaded intrinsic. You can use <tt>llvm.ssub.with.overflow</tt>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6039on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6040
6041<pre>
6042 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6043 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6044 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6045</pre>
6046
6047<h5>Overview:</h5>
6048
6049<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
6050a signed subtraction of the two arguments, and indicate whether an overflow
6051occurred during the signed subtraction.</p>
6052
6053<h5>Arguments:</h5>
6054
6055<p>The arguments (%a and %b) and the first element of the result structure may
6056be of integer types of any bit width, but they must have the same bit width. The
6057second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
6058and <tt>%b</tt> are the two values that will undergo signed subtraction.</p>
6059
6060<h5>Semantics:</h5>
6061
6062<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
6063a signed subtraction of the two arguments. They return a structure &mdash; the
6064first element of which is the subtraction, and the second element of which is a bit
6065specifying if the signed subtraction resulted in an overflow.</p>
6066
6067<h5>Examples:</h5>
6068<pre>
6069 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6070 %sum = extractvalue {i32, i1} %res, 0
6071 %obit = extractvalue {i32, i1} %res, 1
6072 br i1 %obit, label %overflow, label %normal
6073</pre>
6074
6075</div>
6076
6077<!-- _______________________________________________________________________ -->
6078<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6079 <a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6080</div>
6081
6082<div class="doc_text">
6083
6084<h5>Syntax:</h5>
6085
6086<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6087on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6088
6089<pre>
6090 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6091 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6092 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6093</pre>
6094
6095<h5>Overview:</h5>
6096
6097<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
6098an unsigned subtraction of the two arguments, and indicate whether an overflow
6099occurred during the unsigned subtraction.</p>
6100
6101<h5>Arguments:</h5>
6102
6103<p>The arguments (%a and %b) and the first element of the result structure may
6104be of integer types of any bit width, but they must have the same bit width. The
6105second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
6106and <tt>%b</tt> are the two values that will undergo unsigned subtraction.</p>
6107
6108<h5>Semantics:</h5>
6109
6110<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
6111an unsigned subtraction of the two arguments. They return a structure &mdash; the
6112first element of which is the subtraction, and the second element of which is a bit
6113specifying if the unsigned subtraction resulted in an overflow.</p>
6114
6115<h5>Examples:</h5>
6116<pre>
6117 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6118 %sum = extractvalue {i32, i1} %res, 0
6119 %obit = extractvalue {i32, i1} %res, 1
6120 br i1 %obit, label %overflow, label %normal
6121</pre>
6122
6123</div>
6124
6125<!-- _______________________________________________________________________ -->
6126<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6127 <a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6128</div>
6129
6130<div class="doc_text">
6131
6132<h5>Syntax:</h5>
6133
6134<p>This is an overloaded intrinsic. You can use <tt>llvm.smul.with.overflow</tt>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6135on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6136
6137<pre>
6138 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6139 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6140 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6141</pre>
6142
6143<h5>Overview:</h5>
6144
6145<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
6146a signed multiplication of the two arguments, and indicate whether an overflow
6147occurred during the signed multiplication.</p>
6148
6149<h5>Arguments:</h5>
6150
6151<p>The arguments (%a and %b) and the first element of the result structure may
6152be of integer types of any bit width, but they must have the same bit width. The
6153second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
6154and <tt>%b</tt> are the two values that will undergo signed multiplication.</p>
6155
6156<h5>Semantics:</h5>
6157
6158<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
6159a signed multiplication of the two arguments. They return a structure &mdash;
6160the first element of which is the multiplication, and the second element of
6161which is a bit specifying if the signed multiplication resulted in an
6162overflow.</p>
6163
6164<h5>Examples:</h5>
6165<pre>
6166 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6167 %sum = extractvalue {i32, i1} %res, 0
6168 %obit = extractvalue {i32, i1} %res, 1
6169 br i1 %obit, label %overflow, label %normal
6170</pre>
6171
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]6172</div>
6173
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame^]6174<!-- _______________________________________________________________________ -->
6175<div class="doc_subsubsection">
6176 <a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
6177</div>
6178
6179<div class="doc_text">
6180
6181<h5>Syntax:</h5>
6182
6183<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
6184on any integer bit width.</p>
6185
6186<pre>
6187 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6188 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6189 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6190</pre>
6191
6192<h5>Overview:</h5>
6193
6194<p><i><b>Warning:</b> '<tt>llvm.umul.with.overflow</tt>' is badly broken. It is
6195actively being fixed, but it should not currently be used!</i></p>
6196
6197<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
6198a unsigned multiplication of the two arguments, and indicate whether an overflow
6199occurred during the unsigned multiplication.</p>
6200
6201<h5>Arguments:</h5>
6202
6203<p>The arguments (%a and %b) and the first element of the result structure may
6204be of integer types of any bit width, but they must have the same bit width. The
6205second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
6206and <tt>%b</tt> are the two values that will undergo unsigned
6207multiplication.</p>
6208
6209<h5>Semantics:</h5>
6210
6211<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
6212an unsigned multiplication of the two arguments. They return a structure &mdash;
6213the first element of which is the multiplication, and the second element of
6214which is a bit specifying if the unsigned multiplication resulted in an
6215overflow.</p>
6216
6217<h5>Examples:</h5>
6218<pre>
6219 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6220 %sum = extractvalue {i32, i1} %res, 0
6221 %obit = extractvalue {i32, i1} %res, 1
6222 br i1 %obit, label %overflow, label %normal
6223</pre>
6224
6225</div>
6226
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6227<!-- ======================================================================= -->
6228<div class="doc_subsection">
6229 <a name="int_debugger">Debugger Intrinsics</a>
6230</div>
6231
6232<div class="doc_text">
6233<p>
6234The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
6235are described in the <a
6236href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
6237Debugging</a> document.
6238</p>
6239</div>
6240
6241
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6242<!-- ======================================================================= -->
6243<div class="doc_subsection">
6244 <a name="int_eh">Exception Handling Intrinsics</a>
6245</div>
6246
6247<div class="doc_text">
6248<p> The LLVM exception handling intrinsics (which all start with
6249<tt>llvm.eh.</tt> prefix), are described in the <a
6250href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
6251Handling</a> document. </p>
6252</div>
6253
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6254<!-- ======================================================================= -->
6255<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6256 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6257</div>
6258
6259<div class="doc_text">
6260<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6261 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6262 the <tt>nest</tt> attribute, from a function. The result is a callable
6263 function pointer lacking the nest parameter - the caller does not need
6264 to provide a value for it. Instead, the value to use is stored in
6265 advance in a "trampoline", a block of memory usually allocated
6266 on the stack, which also contains code to splice the nest value into the
6267 argument list. This is used to implement the GCC nested function address
6268 extension.
6269</p>
6270<p>
6271 For example, if the function is
6272 <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]6273 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]6274<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6275 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
6276 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
6277 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
6278 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6279</pre>
Bill Wendling03295ca2007-09-22 09:23:55 +0000[diff] [blame]6280 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
6281 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6282</div>
6283
6284<!-- _______________________________________________________________________ -->
6285<div class="doc_subsubsection">
6286 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
6287</div>
6288<div class="doc_text">
6289<h5>Syntax:</h5>
6290<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6291declare 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]6292</pre>
6293<h5>Overview:</h5>
6294<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6295 This fills the memory pointed to by <tt>tramp</tt> with code
6296 and returns a function pointer suitable for executing it.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6297</p>
6298<h5>Arguments:</h5>
6299<p>
6300 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
6301 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
6302 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsc00c2ba2007-08-22 23:39:54 +0000[diff] [blame]6303 intrinsic. Note that the size and the alignment are target-specific - LLVM
6304 currently provides no portable way of determining them, so a front-end that
6305 generates this intrinsic needs to have some target-specific knowledge.
6306 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]6307</p>
6308<h5>Semantics:</h5>
6309<p>
6310 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6311 dependent code, turning it into a function. A pointer to this function is
6312 returned, but needs to be bitcast to an
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6313 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6314 before being called. The new function's signature is the same as that of
6315 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
6316 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
6317 of pointer type. Calling the new function is equivalent to calling
6318 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
6319 missing <tt>nest</tt> argument. If, after calling
6320 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
6321 modified, then the effect of any later call to the returned function pointer is
6322 undefined.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6323</p>
6324</div>
6325
6326<!-- ======================================================================= -->
6327<div class="doc_subsection">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6328 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
6329</div>
6330
6331<div class="doc_text">
6332<p>
6333 These intrinsic functions expand the "universal IR" of LLVM to represent
6334 hardware constructs for atomic operations and memory synchronization. This
6335 provides an interface to the hardware, not an interface to the programmer. It
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]6336 is aimed at a low enough level to allow any programming models or APIs
6337 (Application Programming Interfaces) which
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6338 need atomic behaviors to map cleanly onto it. It is also modeled primarily on
6339 hardware behavior. Just as hardware provides a "universal IR" for source
6340 languages, it also provides a starting point for developing a "universal"
6341 atomic operation and synchronization IR.
6342</p>
6343<p>
6344 These do <em>not</em> form an API such as high-level threading libraries,
6345 software transaction memory systems, atomic primitives, and intrinsic
6346 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
6347 application libraries. The hardware interface provided by LLVM should allow
6348 a clean implementation of all of these APIs and parallel programming models.
6349 No one model or paradigm should be selected above others unless the hardware
6350 itself ubiquitously does so.
6351
6352</p>
6353</div>
6354
6355<!-- _______________________________________________________________________ -->
6356<div class="doc_subsubsection">
6357 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
6358</div>
6359<div class="doc_text">
6360<h5>Syntax:</h5>
6361<pre>
6362declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;,
6363i1 &lt;device&gt; )
6364
6365</pre>
6366<h5>Overview:</h5>
6367<p>
6368 The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
6369 specific pairs of memory access types.
6370</p>
6371<h5>Arguments:</h5>
6372<p>
6373 The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
6374 The first four arguments enables a specific barrier as listed below. The fith
6375 argument specifies that the barrier applies to io or device or uncached memory.
6376
6377</p>
6378 <ul>
6379 <li><tt>ll</tt>: load-load barrier</li>
6380 <li><tt>ls</tt>: load-store barrier</li>
6381 <li><tt>sl</tt>: store-load barrier</li>
6382 <li><tt>ss</tt>: store-store barrier</li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6383 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6384 </ul>
6385<h5>Semantics:</h5>
6386<p>
6387 This intrinsic causes the system to enforce some ordering constraints upon
6388 the loads and stores of the program. This barrier does not indicate
6389 <em>when</em> any events will occur, it only enforces an <em>order</em> in
6390 which they occur. For any of the specified pairs of load and store operations
6391 (f.ex. load-load, or store-load), all of the first operations preceding the
6392 barrier will complete before any of the second operations succeeding the
6393 barrier begin. Specifically the semantics for each pairing is as follows:
6394</p>
6395 <ul>
6396 <li><tt>ll</tt>: All loads before the barrier must complete before any load
6397 after the barrier begins.</li>
6398
6399 <li><tt>ls</tt>: All loads before the barrier must complete before any
6400 store after the barrier begins.</li>
6401 <li><tt>ss</tt>: All stores before the barrier must complete before any
6402 store after the barrier begins.</li>
6403 <li><tt>sl</tt>: All stores before the barrier must complete before any
6404 load after the barrier begins.</li>
6405 </ul>
6406<p>
6407 These semantics are applied with a logical "and" behavior when more than one
6408 is enabled in a single memory barrier intrinsic.
6409</p>
6410<p>
6411 Backends may implement stronger barriers than those requested when they do not
6412 support as fine grained a barrier as requested. Some architectures do not
6413 need all types of barriers and on such architectures, these become noops.
6414</p>
6415<h5>Example:</h5>
6416<pre>
6417%ptr = malloc i32
6418 store i32 4, %ptr
6419
6420%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
6421 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
6422 <i>; guarantee the above finishes</i>
6423 store i32 8, %ptr <i>; before this begins</i>
6424</pre>
6425</div>
6426
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6427<!-- _______________________________________________________________________ -->
6428<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6429 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6430</div>
6431<div class="doc_text">
6432<h5>Syntax:</h5>
6433<p>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6434 This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
6435 any integer bit width and for different address spaces. Not all targets
6436 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6437
6438<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6439declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6440declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6441declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
6442declare 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]6443
6444</pre>
6445<h5>Overview:</h5>
6446<p>
6447 This loads a value in memory and compares it to a given value. If they are
6448 equal, it stores a new value into the memory.
6449</p>
6450<h5>Arguments:</h5>
6451<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6452 The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6453 well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
6454 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
6455 this integer type. While any bit width integer may be used, targets may only
6456 lower representations they support in hardware.
6457
6458</p>
6459<h5>Semantics:</h5>
6460<p>
6461 This entire intrinsic must be executed atomically. It first loads the value
6462 in memory pointed to by <tt>ptr</tt> and compares it with the value
6463 <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
6464 loaded value is yielded in all cases. This provides the equivalent of an
6465 atomic compare-and-swap operation within the SSA framework.
6466</p>
6467<h5>Examples:</h5>
6468
6469<pre>
6470%ptr = malloc i32
6471 store i32 4, %ptr
6472
6473%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6474%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6475 <i>; yields {i32}:result1 = 4</i>
6476%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6477%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6478
6479%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6480%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6481 <i>; yields {i32}:result2 = 8</i>
6482%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6483
6484%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6485</pre>
6486</div>
6487
6488<!-- _______________________________________________________________________ -->
6489<div class="doc_subsubsection">
6490 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6491</div>
6492<div class="doc_text">
6493<h5>Syntax:</h5>
6494
6495<p>
6496 This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6497 integer bit width. Not all targets support all bit widths however.</p>
6498<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6499declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6500declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6501declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6502declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6503
6504</pre>
6505<h5>Overview:</h5>
6506<p>
6507 This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6508 the value from memory. It then stores the value in <tt>val</tt> in the memory
6509 at <tt>ptr</tt>.
6510</p>
6511<h5>Arguments:</h5>
6512
6513<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6514 The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6515 <tt>val</tt> argument and the result must be integers of the same bit width.
6516 The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6517 integer type. The targets may only lower integer representations they
6518 support.
6519</p>
6520<h5>Semantics:</h5>
6521<p>
6522 This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6523 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6524 equivalent of an atomic swap operation within the SSA framework.
6525
6526</p>
6527<h5>Examples:</h5>
6528<pre>
6529%ptr = malloc i32
6530 store i32 4, %ptr
6531
6532%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6533%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6534 <i>; yields {i32}:result1 = 4</i>
6535%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6536%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6537
6538%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6539%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6540 <i>; yields {i32}:result2 = 8</i>
6541
6542%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6543%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6544</pre>
6545</div>
6546
6547<!-- _______________________________________________________________________ -->
6548<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6549 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6550
6551</div>
6552<div class="doc_text">
6553<h5>Syntax:</h5>
6554<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6555 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]6556 integer bit width. Not all targets support all bit widths however.</p>
6557<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6558declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6559declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6560declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6561declare 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]6562
6563</pre>
6564<h5>Overview:</h5>
6565<p>
6566 This intrinsic adds <tt>delta</tt> to the value stored in memory at
6567 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6568</p>
6569<h5>Arguments:</h5>
6570<p>
6571
6572 The intrinsic takes two arguments, the first a pointer to an integer value
6573 and the second an integer value. The result is also an integer value. These
6574 integer types can have any bit width, but they must all have the same bit
6575 width. The targets may only lower integer representations they support.
6576</p>
6577<h5>Semantics:</h5>
6578<p>
6579 This intrinsic does a series of operations atomically. It first loads the
6580 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6581 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6582</p>
6583
6584<h5>Examples:</h5>
6585<pre>
6586%ptr = malloc i32
6587 store i32 4, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6588%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6589 <i>; yields {i32}:result1 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6590%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6591 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6592%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6593 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6594%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6595</pre>
6596</div>
6597
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6598<!-- _______________________________________________________________________ -->
6599<div class="doc_subsubsection">
6600 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6601
6602</div>
6603<div class="doc_text">
6604<h5>Syntax:</h5>
6605<p>
6606 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]6607 any integer bit width and for different address spaces. Not all targets
6608 support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6609<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6610declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6611declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6612declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6613declare 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]6614
6615</pre>
6616<h5>Overview:</h5>
6617<p>
6618 This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6619 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6620</p>
6621<h5>Arguments:</h5>
6622<p>
6623
6624 The intrinsic takes two arguments, the first a pointer to an integer value
6625 and the second an integer value. The result is also an integer value. These
6626 integer types can have any bit width, but they must all have the same bit
6627 width. The targets may only lower integer representations they support.
6628</p>
6629<h5>Semantics:</h5>
6630<p>
6631 This intrinsic does a series of operations atomically. It first loads the
6632 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6633 result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6634</p>
6635
6636<h5>Examples:</h5>
6637<pre>
6638%ptr = malloc i32
6639 store i32 8, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6640%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6641 <i>; yields {i32}:result1 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6642%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6643 <i>; yields {i32}:result2 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6644%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6645 <i>; yields {i32}:result3 = 2</i>
6646%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6647</pre>
6648</div>
6649
6650<!-- _______________________________________________________________________ -->
6651<div class="doc_subsubsection">
6652 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6653 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6654 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6655 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
6656
6657</div>
6658<div class="doc_text">
6659<h5>Syntax:</h5>
6660<p>
6661 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
6662 <tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6663 <tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
6664 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6665<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6666declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6667declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6668declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6669declare 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]6670
6671</pre>
6672
6673<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6674declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6675declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6676declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6677declare 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]6678
6679</pre>
6680
6681<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6682declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6683declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6684declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6685declare 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]6686
6687</pre>
6688
6689<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6690declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6691declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6692declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6693declare 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]6694
6695</pre>
6696<h5>Overview:</h5>
6697<p>
6698 These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6699 the value stored in memory at <tt>ptr</tt>. It yields the original value
6700 at <tt>ptr</tt>.
6701</p>
6702<h5>Arguments:</h5>
6703<p>
6704
6705 These intrinsics take two arguments, the first a pointer to an integer value
6706 and the second an integer value. The result is also an integer value. These
6707 integer types can have any bit width, but they must all have the same bit
6708 width. The targets may only lower integer representations they support.
6709</p>
6710<h5>Semantics:</h5>
6711<p>
6712 These intrinsics does a series of operations atomically. They first load the
6713 value stored at <tt>ptr</tt>. They then do the bitwise operation
6714 <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
6715 value stored at <tt>ptr</tt>.
6716</p>
6717
6718<h5>Examples:</h5>
6719<pre>
6720%ptr = malloc i32
6721 store i32 0x0F0F, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6722%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6723 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6724%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6725 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6726%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6727 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6728%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6729 <i>; yields {i32}:result3 = FF</i>
6730%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6731</pre>
6732</div>
6733
6734
6735<!-- _______________________________________________________________________ -->
6736<div class="doc_subsubsection">
6737 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6738 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6739 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6740 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
6741
6742</div>
6743<div class="doc_text">
6744<h5>Syntax:</h5>
6745<p>
6746 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6747 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6748 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6749 address spaces. Not all targets
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6750 support all bit widths however.</p>
6751<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6752declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6753declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6754declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6755declare 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]6756
6757</pre>
6758
6759<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6760declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6761declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6762declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6763declare 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]6764
6765</pre>
6766
6767<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6768declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6769declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6770declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6771declare 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]6772
6773</pre>
6774
6775<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6776declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6777declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6778declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6779declare 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]6780
6781</pre>
6782<h5>Overview:</h5>
6783<p>
6784 These intrinsics takes the signed or unsigned minimum or maximum of
6785 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6786 original value at <tt>ptr</tt>.
6787</p>
6788<h5>Arguments:</h5>
6789<p>
6790
6791 These intrinsics take two arguments, the first a pointer to an integer value
6792 and the second an integer value. The result is also an integer value. These
6793 integer types can have any bit width, but they must all have the same bit
6794 width. The targets may only lower integer representations they support.
6795</p>
6796<h5>Semantics:</h5>
6797<p>
6798 These intrinsics does a series of operations atomically. They first load the
6799 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
6800 <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
6801 the original value stored at <tt>ptr</tt>.
6802</p>
6803
6804<h5>Examples:</h5>
6805<pre>
6806%ptr = malloc i32
6807 store i32 7, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6808%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6809 <i>; yields {i32}:result0 = 7</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6810%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6811 <i>; yields {i32}:result1 = -2</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6812%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6813 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6814%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6815 <i>; yields {i32}:result3 = 8</i>
6816%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6817</pre>
6818</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6819
6820<!-- ======================================================================= -->
6821<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6822 <a name="int_general">General Intrinsics</a>
6823</div>
6824
6825<div class="doc_text">
6826<p> This class of intrinsics is designed to be generic and has
6827no specific purpose. </p>
6828</div>
6829
6830<!-- _______________________________________________________________________ -->
6831<div class="doc_subsubsection">
6832 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6833</div>
6834
6835<div class="doc_text">
6836
6837<h5>Syntax:</h5>
6838<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]6839 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]6840</pre>
6841
6842<h5>Overview:</h5>
6843
6844<p>
6845The '<tt>llvm.var.annotation</tt>' intrinsic
6846</p>
6847
6848<h5>Arguments:</h5>
6849
6850<p>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]6851The first argument is a pointer to a value, the second is a pointer to a
6852global string, the third is a pointer to a global string which is the source
6853file name, and the last argument is the line number.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6854</p>
6855
6856<h5>Semantics:</h5>
6857
6858<p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6859This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6860This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6861annotations. These have no other defined use, they are ignored by code
6862generation and optimization.
6863</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6864</div>
6865
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6866<!-- _______________________________________________________________________ -->
6867<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]6868 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6869</div>
6870
6871<div class="doc_text">
6872
6873<h5>Syntax:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6874<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6875any integer bit width.
6876</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6877<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]6878 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6879 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6880 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6881 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6882 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]6883</pre>
6884
6885<h5>Overview:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6886
6887<p>
6888The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6889</p>
6890
6891<h5>Arguments:</h5>
6892
6893<p>
6894The first argument is an integer value (result of some expression),
6895the second is a pointer to a global string, the third is a pointer to a global
6896string which is the source file name, and the last argument is the line number.
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6897It returns the value of the first argument.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6898</p>
6899
6900<h5>Semantics:</h5>
6901
6902<p>
6903This intrinsic allows annotations to be put on arbitrary expressions
6904with arbitrary strings. This can be useful for special purpose optimizations
6905that want to look for these annotations. These have no other defined use, they
6906are ignored by code generation and optimization.
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6907</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6908</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6909
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6910<!-- _______________________________________________________________________ -->
6911<div class="doc_subsubsection">
6912 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6913</div>
6914
6915<div class="doc_text">
6916
6917<h5>Syntax:</h5>
6918<pre>
6919 declare void @llvm.trap()
6920</pre>
6921
6922<h5>Overview:</h5>
6923
6924<p>
6925The '<tt>llvm.trap</tt>' intrinsic
6926</p>
6927
6928<h5>Arguments:</h5>
6929
6930<p>
6931None
6932</p>
6933
6934<h5>Semantics:</h5>
6935
6936<p>
6937This intrinsics is lowered to the target dependent trap instruction. If the
6938target does not have a trap instruction, this intrinsic will be lowered to the
6939call of the abort() function.
6940</p>
6941</div>
6942
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6943<!-- _______________________________________________________________________ -->
6944<div class="doc_subsubsection">
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]6945 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6946</div>
6947<div class="doc_text">
6948<h5>Syntax:</h5>
6949<pre>
6950declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
6951
6952</pre>
6953<h5>Overview:</h5>
6954<p>
6955 The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
6956 it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
6957 it is placed on the stack before local variables.
6958</p>
6959<h5>Arguments:</h5>
6960<p>
6961 The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
6962 first argument is the value loaded from the stack guard
6963 <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
6964 has enough space to hold the value of the guard.
6965</p>
6966<h5>Semantics:</h5>
6967<p>
6968 This intrinsic causes the prologue/epilogue inserter to force the position of
6969 the <tt>AllocaInst</tt> stack slot to be before local variables on the
6970 stack. This is to ensure that if a local variable on the stack is overwritten,
6971 it will destroy the value of the guard. When the function exits, the guard on
6972 the stack is checked against the original guard. If they're different, then
6973 the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
6974</p>
6975</div>
6976
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6977<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6978<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6979<address>
6980 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]6981 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6982 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]6983 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]6984
6985 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]6986 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6987 Last modified: $Date$
6988</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]6989
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6990</body>
6991</html>