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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / ac1df8ef337387b8519dca5873b7d55e16d1fe19 / . / 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>
214 <li><a href="#int_sadd_ovf">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
215 <li><a href="#int_uadd_ovf">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
216 <li><a href="#int_ssub_ovf">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
217 <li><a href="#int_usub_ovf">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
218 <li><a href="#int_smul_ovf">'<tt>llvm.smul.with.overflow.*</tt> Intrinsics</a></li>
219 </ol>
220 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]221 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]222 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]223 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]224 <ol>
225 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]226 </ol>
227 </li>
Bill Wendling3c44f5b2008-11-18 22:10:53 +0000[diff] [blame]228 <li><a href="#int_atomics">Atomic intrinsics</a>
229 <ol>
230 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
231 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
232 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
233 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
234 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
235 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
236 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
237 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
238 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
239 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
240 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
241 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
242 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
243 </ol>
244 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]245 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]246 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]247 <li><a href="#int_var_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]248 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]249 <li><a href="#int_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]250 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]251 <li><a href="#int_trap">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]252 '<tt>llvm.trap</tt>' Intrinsic</a></li>
253 <li><a href="#int_stackprotector">
254 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]255 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]256 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]257 </ol>
258 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]259</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]260
261<div class="doc_author">
262 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
263 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]264</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]265
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]266<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]267<div class="doc_section"> <a name="abstract">Abstract </a></div>
268<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]269
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]270<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]271<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling837f39b2008-08-05 22:29:16 +0000[diff] [blame]272LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]273type safety, low-level operations, flexibility, and the capability of
274representing 'all' high-level languages cleanly. It is the common code
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]275representation used throughout all phases of the LLVM compilation
276strategy.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]277</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]278
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]279<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]280<div class="doc_section"> <a name="introduction">Introduction</a> </div>
281<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]282
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]283<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]284
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]285<p>The LLVM code representation is designed to be used in three
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]286different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]287representation (suitable for fast loading by a Just-In-Time compiler),
288and as a human readable assembly language representation. This allows
289LLVM to provide a powerful intermediate representation for efficient
290compiler transformations and analysis, while providing a natural means
291to debug and visualize the transformations. The three different forms
292of LLVM are all equivalent. This document describes the human readable
293representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]294
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]295<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]296while being expressive, typed, and extensible at the same time. It
297aims to be a "universal IR" of sorts, by being at a low enough level
298that high-level ideas may be cleanly mapped to it (similar to how
299microprocessors are "universal IR's", allowing many source languages to
300be mapped to them). By providing type information, LLVM can be used as
301the target of optimizations: for example, through pointer analysis, it
302can be proven that a C automatic variable is never accessed outside of
303the current function... allowing it to be promoted to a simple SSA
304value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]305
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]306</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]307
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]308<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]309<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]310
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]311<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]312
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]313<p>It is important to note that this document describes 'well formed'
314LLVM assembly language. There is a difference between what the parser
315accepts and what is considered 'well formed'. For example, the
316following instruction is syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]317
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]318<div class="doc_code">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]319<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]320%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]321</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]322</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]323
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]324<p>...because the definition of <tt>%x</tt> does not dominate all of
325its uses. The LLVM infrastructure provides a verification pass that may
326be used to verify that an LLVM module is well formed. This pass is
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]327automatically run by the parser after parsing input assembly and by
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]328the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]329by the verifier pass indicate bugs in transformation passes or input to
330the parser.</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]331</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]332
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]333<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]334
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]335<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]336<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]337<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]338
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]339<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]340
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]341 <p>LLVM identifiers come in two basic types: global and local. Global
342 identifiers (functions, global variables) begin with the @ character. Local
343 identifiers (register names, types) begin with the % character. Additionally,
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]344 there are three different formats for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]345
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]346<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]347 <li>Named values are represented as a string of characters with their prefix.
348 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
349 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]350 Identifiers which require other characters in their names can be surrounded
Daniel Dunbar76dea952008-10-14 23:51:43 +0000[diff] [blame]351 with quotes. Special characters may be escaped using "\xx" where xx is the
352 ASCII code for the character in hexadecimal. In this way, any character can
353 be used in a name value, even quotes themselves.
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]354
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]355 <li>Unnamed values are represented as an unsigned numeric value with their
356 prefix. For example, %12, @2, %44.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]357
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]358 <li>Constants, which are described in a <a href="#constants">section about
359 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]360</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]361
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]362<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]363don't need to worry about name clashes with reserved words, and the set of
364reserved words may be expanded in the future without penalty. Additionally,
365unnamed identifiers allow a compiler to quickly come up with a temporary
366variable without having to avoid symbol table conflicts.</p>
367
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]368<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]369languages. There are keywords for different opcodes
370('<tt><a href="#i_add">add</a></tt>',
371 '<tt><a href="#i_bitcast">bitcast</a></tt>',
372 '<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]373href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]374and others. These reserved words cannot conflict with variable names, because
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]375none of them start with a prefix character ('%' or '@').</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]376
377<p>Here is an example of LLVM code to multiply the integer variable
378'<tt>%X</tt>' by 8:</p>
379
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]380<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]381
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]382<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]383<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]384%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]385</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]386</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]387
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]388<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]389
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]390<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]391<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]392%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]393</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]394</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]395
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]396<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]397
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]398<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]399<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]400<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
401<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
402%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]403</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]404</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]405
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]406<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
407important lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]408
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]409<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]410
411 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
412 line.</li>
413
414 <li>Unnamed temporaries are created when the result of a computation is not
415 assigned to a named value.</li>
416
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]417 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]418
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]419</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]420
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]421<p>...and it also shows a convention that we follow in this document. When
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]422demonstrating instructions, we will follow an instruction with a comment that
423defines the type and name of value produced. Comments are shown in italic
424text.</p>
425
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]426</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]427
428<!-- *********************************************************************** -->
429<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
430<!-- *********************************************************************** -->
431
432<!-- ======================================================================= -->
433<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
434</div>
435
436<div class="doc_text">
437
438<p>LLVM programs are composed of "Module"s, each of which is a
439translation unit of the input programs. Each module consists of
440functions, global variables, and symbol table entries. Modules may be
441combined together with the LLVM linker, which merges function (and
442global variable) definitions, resolves forward declarations, and merges
443symbol table entries. Here is an example of the "hello world" module:</p>
444
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]445<div class="doc_code">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]446<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]447<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
448 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]449
450<i>; External declaration of the puts function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]451<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]452
453<i>; Definition of main function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]454define i32 @main() { <i>; i32()* </i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]455 <i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]456 %cast210 = <a
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]457 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]458
459 <i>; Call puts function to write out the string to stdout...</i>
460 <a
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]461 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]462 <a
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]463 href="#i_ret">ret</a> i32 0<br>}<br>
464</pre>
465</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]466
467<p>This example is made up of a <a href="#globalvars">global variable</a>
468named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
469function, and a <a href="#functionstructure">function definition</a>
470for "<tt>main</tt>".</p>
471
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]472<p>In general, a module is made up of a list of global values,
473where both functions and global variables are global values. Global values are
474represented by a pointer to a memory location (in this case, a pointer to an
475array of char, and a pointer to a function), and have one of the following <a
476href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]477
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]478</div>
479
480<!-- ======================================================================= -->
481<div class="doc_subsection">
482 <a name="linkage">Linkage Types</a>
483</div>
484
485<div class="doc_text">
486
487<p>
488All Global Variables and Functions have one of the following types of linkage:
489</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]490
491<dl>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]492
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]493 <dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
494
495 <dd>Global values with private linkage are only directly accessible by
496 objects in the current module. In particular, linking code into a module with
497 an private global value may cause the private to be renamed as necessary to
498 avoid collisions. Because the symbol is private to the module, all
499 references can be updated. This doesn't show up in any symbol table in the
500 object file.
501 </dd>
502
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]503 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]504
Duncan Sands81d05c22009-01-16 09:29:46 +0000[diff] [blame]505 <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]506 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]507 '<tt>static</tt>' keyword in C.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]508 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]509
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]510 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]511
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]512 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
513 the same name when linkage occurs. This is typically used to implement
514 inline functions, templates, or other code which must be generated in each
515 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
516 allowed to be discarded.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]517 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]518
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]519 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
520
521 <dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
522 linkage, except that unreferenced <tt>common</tt> globals may not be
523 discarded. This is used for globals that may be emitted in multiple
524 translation units, but that are not guaranteed to be emitted into every
525 translation unit that uses them. One example of this is tentative
526 definitions in C, such as "<tt>int X;</tt>" at global scope.
527 </dd>
528
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]529 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]530
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]531 <dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
532 that some targets may choose to emit different assembly sequences for them
533 for target-dependent reasons. This is used for globals that are declared
534 "weak" in C source code.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]535 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]536
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]537 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]538
539 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
540 pointer to array type. When two global variables with appending linkage are
541 linked together, the two global arrays are appended together. This is the
542 LLVM, typesafe, equivalent of having the system linker append together
543 "sections" with identical names when .o files are linked.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]544 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]545
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]546 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]547 <dd>The semantics of this linkage follow the ELF object file model: the
548 symbol is weak until linked, if not linked, the symbol becomes null instead
549 of being an undefined reference.
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]550 </dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]551
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]552 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]553
554 <dd>If none of the above identifiers are used, the global is externally
555 visible, meaning that it participates in linkage and can be used to resolve
556 external symbol references.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]557 </dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]558</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]559
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]560 <p>
561 The next two types of linkage are targeted for Microsoft Windows platform
562 only. They are designed to support importing (exporting) symbols from (to)
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]563 DLLs (Dynamic Link Libraries).
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]564 </p>
565
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]566 <dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]567 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
568
569 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
570 or variable via a global pointer to a pointer that is set up by the DLL
571 exporting the symbol. On Microsoft Windows targets, the pointer name is
Dan Gohman79564122009-01-12 21:35:55 +0000[diff] [blame]572 formed by combining <code>__imp_</code> and the function or variable name.
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]573 </dd>
574
575 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
576
577 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
578 pointer to a pointer in a DLL, so that it can be referenced with the
579 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
Dan Gohman79564122009-01-12 21:35:55 +0000[diff] [blame]580 name is formed by combining <code>__imp_</code> and the function or variable
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]581 name.
582 </dd>
583
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]584</dl>
585
Dan Gohmanf0032762008-11-24 17:18:39 +0000[diff] [blame]586<p>For example, since the "<tt>.LC0</tt>"
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]587variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
588variable and was linked with this one, one of the two would be renamed,
589preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
590external (i.e., lacking any linkage declarations), they are accessible
Reid Spencerac8d2762007-01-05 00:59:10 +0000[diff] [blame]591outside of the current module.</p>
592<p>It is illegal for a function <i>declaration</i>
593to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]594or <tt>extern_weak</tt>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]595<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]596linkages.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]597</div>
598
599<!-- ======================================================================= -->
600<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]601 <a name="callingconv">Calling Conventions</a>
602</div>
603
604<div class="doc_text">
605
606<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
607and <a href="#i_invoke">invokes</a> can all have an optional calling convention
608specified for the call. The calling convention of any pair of dynamic
609caller/callee must match, or the behavior of the program is undefined. The
610following calling conventions are supported by LLVM, and more may be added in
611the future:</p>
612
613<dl>
614 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
615
616 <dd>This calling convention (the default if no other calling convention is
617 specified) matches the target C calling conventions. This calling convention
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]618 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencerc28d2bc2006-12-31 21:30:18 +0000[diff] [blame]619 prototype and implemented declaration of the function (as does normal C).
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]620 </dd>
621
622 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
623
624 <dd>This calling convention attempts to make calls as fast as possible
625 (e.g. by passing things in registers). This calling convention allows the
626 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]627 without having to conform to an externally specified ABI (Application Binary
628 Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer9097d142008-05-14 09:17:12 +0000[diff] [blame]629 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
630 supported. This calling convention does not support varargs and requires the
631 prototype of all callees to exactly match the prototype of the function
632 definition.
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]633 </dd>
634
635 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
636
637 <dd>This calling convention attempts to make code in the caller as efficient
638 as possible under the assumption that the call is not commonly executed. As
639 such, these calls often preserve all registers so that the call does not break
640 any live ranges in the caller side. This calling convention does not support
641 varargs and requires the prototype of all callees to exactly match the
642 prototype of the function definition.
643 </dd>
644
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]645 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]646
647 <dd>Any calling convention may be specified by number, allowing
648 target-specific calling conventions to be used. Target specific calling
649 conventions start at 64.
650 </dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]651</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]652
653<p>More calling conventions can be added/defined on an as-needed basis, to
654support pascal conventions or any other well-known target-independent
655convention.</p>
656
657</div>
658
659<!-- ======================================================================= -->
660<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]661 <a name="visibility">Visibility Styles</a>
662</div>
663
664<div class="doc_text">
665
666<p>
667All Global Variables and Functions have one of the following visibility styles:
668</p>
669
670<dl>
671 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
672
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]673 <dd>On targets that use the ELF object file format, default visibility means
674 that the declaration is visible to other
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]675 modules and, in shared libraries, means that the declared entity may be
676 overridden. On Darwin, default visibility means that the declaration is
677 visible to other modules. Default visibility corresponds to "external
678 linkage" in the language.
679 </dd>
680
681 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
682
683 <dd>Two declarations of an object with hidden visibility refer to the same
684 object if they are in the same shared object. Usually, hidden visibility
685 indicates that the symbol will not be placed into the dynamic symbol table,
686 so no other module (executable or shared library) can reference it
687 directly.
688 </dd>
689
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]690 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
691
692 <dd>On ELF, protected visibility indicates that the symbol will be placed in
693 the dynamic symbol table, but that references within the defining module will
694 bind to the local symbol. That is, the symbol cannot be overridden by another
695 module.
696 </dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]697</dl>
698
699</div>
700
701<!-- ======================================================================= -->
702<div class="doc_subsection">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]703 <a name="namedtypes">Named Types</a>
704</div>
705
706<div class="doc_text">
707
708<p>LLVM IR allows you to specify name aliases for certain types. This can make
709it easier to read the IR and make the IR more condensed (particularly when
710recursive types are involved). An example of a name specification is:
711</p>
712
713<div class="doc_code">
714<pre>
715%mytype = type { %mytype*, i32 }
716</pre>
717</div>
718
719<p>You may give a name to any <a href="#typesystem">type</a> except "<a
720href="t_void">void</a>". Type name aliases may be used anywhere a type is
721expected with the syntax "%mytype".</p>
722
723<p>Note that type names are aliases for the structural type that they indicate,
724and that you can therefore specify multiple names for the same type. This often
725leads to confusing behavior when dumping out a .ll file. Since LLVM IR uses
726structural typing, the name is not part of the type. When printing out LLVM IR,
727the printer will pick <em>one name</em> to render all types of a particular
728shape. This means that if you have code where two different source types end up
729having the same LLVM type, that the dumper will sometimes print the "wrong" or
730unexpected type. This is an important design point and isn't going to
731change.</p>
732
733</div>
734
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]735<!-- ======================================================================= -->
736<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]737 <a name="globalvars">Global Variables</a>
738</div>
739
740<div class="doc_text">
741
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]742<p>Global variables define regions of memory allocated at compilation time
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]743instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]744an explicit section to be placed in, and may have an optional explicit alignment
745specified. A variable may be defined as "thread_local", which means that it
746will not be shared by threads (each thread will have a separated copy of the
747variable). A variable may be defined as a global "constant," which indicates
748that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]749optimization, allowing the global data to be placed in the read-only section of
750an executable, etc). Note that variables that need runtime initialization
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]751cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]752
753<p>
754LLVM explicitly allows <em>declarations</em> of global variables to be marked
755constant, even if the final definition of the global is not. This capability
756can be used to enable slightly better optimization of the program, but requires
757the language definition to guarantee that optimizations based on the
758'constantness' are valid for the translation units that do not include the
759definition.
760</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]761
762<p>As SSA values, global variables define pointer values that are in
763scope (i.e. they dominate) all basic blocks in the program. Global
764variables always define a pointer to their "content" type because they
765describe a region of memory, and all memory objects in LLVM are
766accessed through pointers.</p>
767
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]768<p>A global variable may be declared to reside in a target-specifc numbered
769address space. For targets that support them, address spaces may affect how
770optimizations are performed and/or what target instructions are used to access
Christopher Lambd49e18d2007-12-12 08:44:39 +0000[diff] [blame]771the variable. The default address space is zero. The address space qualifier
772must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]773
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]774<p>LLVM allows an explicit section to be specified for globals. If the target
775supports it, it will emit globals to the section specified.</p>
776
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]777<p>An explicit alignment may be specified for a global. If not present, or if
778the alignment is set to zero, the alignment of the global is set by the target
779to whatever it feels convenient. If an explicit alignment is specified, the
780global is forced to have at least that much alignment. All alignments must be
781a power of 2.</p>
782
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]783<p>For example, the following defines a global in a numbered address space with
784an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]785
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]786<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]787<pre>
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]788@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]789</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]790</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]791
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]792</div>
793
794
795<!-- ======================================================================= -->
796<div class="doc_subsection">
797 <a name="functionstructure">Functions</a>
798</div>
799
800<div class="doc_text">
801
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]802<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
803an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]804<a href="#visibility">visibility style</a>, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]805<a href="#callingconv">calling convention</a>, a return type, an optional
806<a href="#paramattrs">parameter attribute</a> for the return type, a function
807name, a (possibly empty) argument list (each with optional
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]808<a href="#paramattrs">parameter attributes</a>), optional
809<a href="#fnattrs">function attributes</a>, an optional section,
810an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner0c46a7d2008-10-04 18:10:21 +0000[diff] [blame]811an opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]812
813LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
814optional <a href="#linkage">linkage type</a>, an optional
815<a href="#visibility">visibility style</a>, an optional
816<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]817<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]818name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksene754abe2007-12-10 03:30:21 +0000[diff] [blame]819<a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]820
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]821<p>A function definition contains a list of basic blocks, forming the CFG
822(Control Flow Graph) for
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]823the function. Each basic block may optionally start with a label (giving the
824basic block a symbol table entry), contains a list of instructions, and ends
825with a <a href="#terminators">terminator</a> instruction (such as a branch or
826function return).</p>
827
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]828<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]829executed on entrance to the function, and it is not allowed to have predecessor
830basic blocks (i.e. there can not be any branches to the entry block of a
831function). Because the block can have no predecessors, it also cannot have any
832<a href="#i_phi">PHI nodes</a>.</p>
833
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]834<p>LLVM allows an explicit section to be specified for functions. If the target
835supports it, it will emit functions to the section specified.</p>
836
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]837<p>An explicit alignment may be specified for a function. If not present, or if
838the alignment is set to zero, the alignment of the function is set by the target
839to whatever it feels convenient. If an explicit alignment is specified, the
840function is forced to have at least that much alignment. All alignments must be
841a power of 2.</p>
842
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]843 <h5>Syntax:</h5>
844
845<div class="doc_code">
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]846<tt>
847define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
848 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
849 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
850 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
851 [<a href="#gc">gc</a>] { ... }
852</tt>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]853</div>
854
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]855</div>
856
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]857
858<!-- ======================================================================= -->
859<div class="doc_subsection">
860 <a name="aliasstructure">Aliases</a>
861</div>
862<div class="doc_text">
863 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov726d45c2008-03-22 08:36:14 +0000[diff] [blame]864 function, global variable, another alias or bitcast of global value). Aliases
865 may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]866 optional <a href="#visibility">visibility style</a>.</p>
867
868 <h5>Syntax:</h5>
869
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]870<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]871<pre>
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]872@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]873</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]874</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]875
876</div>
877
878
879
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]880<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]881<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
882<div class="doc_text">
883 <p>The return type and each parameter of a function type may have a set of
884 <i>parameter attributes</i> associated with them. Parameter attributes are
885 used to communicate additional information about the result or parameters of
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]886 a function. Parameter attributes are considered to be part of the function,
887 not of the function type, so functions with different parameter attributes
888 can have the same function type.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]889
Reid Spencer950e9f82007-01-15 18:27:39 +0000[diff] [blame]890 <p>Parameter attributes are simple keywords that follow the type specified. If
891 multiple parameter attributes are needed, they are space separated. For
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]892 example:</p>
893
894<div class="doc_code">
895<pre>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]896declare i32 @printf(i8* noalias , ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]897declare i32 @atoi(i8 zeroext)
898declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]899</pre>
900</div>
901
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]902 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
903 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]904
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]905 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]906 <dl>
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]907 <dt><tt>zeroext</tt></dt>
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]908 <dd>This indicates to the code generator that the parameter or return value
909 should be zero-extended to a 32-bit value by the caller (for a parameter)
910 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]911
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]912 <dt><tt>signext</tt></dt>
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]913 <dd>This indicates to the code generator that the parameter or return value
914 should be sign-extended to a 32-bit value by the caller (for a parameter)
915 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]916
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]917 <dt><tt>inreg</tt></dt>
Dale Johannesenc9c6da62008-09-25 20:47:45 +0000[diff] [blame]918 <dd>This indicates that this parameter or return value should be treated
919 in a special target-dependent fashion during while emitting code for a
920 function call or return (usually, by putting it in a register as opposed
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]921 to memory, though some targets use it to distinguish between two different
922 kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]923
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]924 <dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner0747baa2008-01-15 04:34:22 +0000[diff] [blame]925 <dd>This indicates that the pointer parameter should really be passed by
926 value to the function. The attribute implies that a hidden copy of the
927 pointee is made between the caller and the callee, so the callee is unable
Chris Lattnerebec6782008-08-05 18:21:08 +0000[diff] [blame]928 to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner0747baa2008-01-15 04:34:22 +0000[diff] [blame]929 pointer arguments. It is generally used to pass structs and arrays by
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]930 value, but is also valid on pointers to scalars. The copy is considered to
931 belong to the caller not the callee (for example,
932 <tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]933 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattnerce459b12009-02-05 05:42:28 +0000[diff] [blame]934 values. The byval attribute also supports specifying an alignment with the
935 align attribute. This has a target-specific effect on the code generator
936 that usually indicates a desired alignment for the synthesized stack
937 slot.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]938
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]939 <dt><tt>sret</tt></dt>
Duncan Sandse26dec62008-02-18 04:19:38 +0000[diff] [blame]940 <dd>This indicates that the pointer parameter specifies the address of a
941 structure that is the return value of the function in the source program.
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]942 This pointer must be guaranteed by the caller to be valid: loads and stores
943 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]944 be applied to the first parameter. This is not a valid attribute for
945 return values. </dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]946
Zhou Shengfebca342007-06-05 05:28:26 +0000[diff] [blame]947 <dt><tt>noalias</tt></dt>
Nick Lewycky02ff3082008-11-24 03:41:24 +0000[diff] [blame]948 <dd>This indicates that the pointer does not alias any global or any other
949 parameter. The caller is responsible for ensuring that this is the
Nick Lewyckyb2b32fd2008-11-24 05:00:44 +0000[diff] [blame]950 case. On a function return value, <tt>noalias</tt> additionally indicates
951 that the pointer does not alias any other pointers visible to the
Nick Lewyckyf23d0d32008-12-19 06:39:12 +0000[diff] [blame]952 caller. For further details, please see the discussion of the NoAlias
953 response in
954 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
955 analysis</a>.</dd>
956
957 <dt><tt>nocapture</tt></dt>
958 <dd>This indicates that the callee does not make any copies of the pointer
959 that outlive the callee itself. This is not a valid attribute for return
960 values.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]961
Duncan Sands50f19f52007-07-27 19:57:41 +0000[diff] [blame]962 <dt><tt>nest</tt></dt>
Duncan Sands0789b8b2008-07-08 09:27:25 +0000[diff] [blame]963 <dd>This indicates that the pointer parameter can be excised using the
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]964 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
965 attribute for return values.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]966 </dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]967
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]968</div>
969
970<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]971<div class="doc_subsection">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]972 <a name="gc">Garbage Collector Names</a>
973</div>
974
975<div class="doc_text">
976<p>Each function may specify a garbage collector name, which is simply a
977string.</p>
978
979<div class="doc_code"><pre
980>define void @f() gc "name" { ...</pre></div>
981
982<p>The compiler declares the supported values of <i>name</i>. Specifying a
983collector which will cause the compiler to alter its output in order to support
984the named garbage collection algorithm.</p>
985</div>
986
987<!-- ======================================================================= -->
988<div class="doc_subsection">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]989 <a name="fnattrs">Function Attributes</a>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]990</div>
991
992<div class="doc_text">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]993
994<p>Function attributes are set to communicate additional information about
995 a function. Function attributes are considered to be part of the function,
996 not of the function type, so functions with different parameter attributes
997 can have the same function type.</p>
998
999 <p>Function attributes are simple keywords that follow the type specified. If
1000 multiple attributes are needed, they are space separated. For
1001 example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1002
1003<div class="doc_code">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1004<pre>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1005define void @f() noinline { ... }
1006define void @f() alwaysinline { ... }
1007define void @f() alwaysinline optsize { ... }
1008define void @f() optsize
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1009</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1010</div>
1011
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1012<dl>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1013<dt><tt>alwaysinline</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1014<dd>This attribute indicates that the inliner should attempt to inline this
1015function into callers whenever possible, ignoring any active inlining size
1016threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1017
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1018<dt><tt>noinline</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1019<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner94b5f7d2008-10-05 17:14:59 +0000[diff] [blame]1020in any situation. This attribute may not be used together with the
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1021<tt>alwaysinline</tt> attribute.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1022
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1023<dt><tt>optsize</tt></dt>
Devang Patel66c6c652008-09-29 18:34:44 +0000[diff] [blame]1024<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1025make choices that keep the code size of this function low, and otherwise do
1026optimizations specifically to reduce code size.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1027
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1028<dt><tt>noreturn</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1029<dd>This function attribute indicates that the function never returns normally.
1030This produces undefined behavior at runtime if the function ever does
1031dynamically return.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1032
1033<dt><tt>nounwind</tt></dt>
Chris Lattner88d4b592008-10-04 18:23:17 +0000[diff] [blame]1034<dd>This function attribute indicates that the function never returns with an
1035unwind or exceptional control flow. If the function does unwind, its runtime
1036behavior is undefined.</dd>
1037
1038<dt><tt>readnone</tt></dt>
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]1039<dd>This attribute indicates that the function computes its result (or the
1040exception it throws) based strictly on its arguments, without dereferencing any
1041pointer arguments or otherwise accessing any mutable state (e.g. memory, control
1042registers, etc) visible to caller functions. It does not write through any
1043pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
1044never changes any state visible to callers.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1045
Duncan Sandsedb05df2008-10-06 08:14:18 +0000[diff] [blame]1046<dt><tt><a name="readonly">readonly</a></tt></dt>
1047<dd>This attribute indicates that the function does not write through any
1048pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
1049or otherwise modify any state (e.g. memory, control registers, etc) visible to
1050caller functions. It may dereference pointer arguments and read state that may
1051be set in the caller. A readonly function always returns the same value (or
1052throws the same exception) when called with the same set of arguments and global
1053state.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1054
1055<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1056<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1057protector. It is in the form of a "canary"&mdash;a random value placed on the
1058stack before the local variables that's checked upon return from the function to
1059see if it has been overwritten. A heuristic is used to determine if a function
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1060needs stack protectors or not.
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1061
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1062<p>If a function that has an <tt>ssp</tt> attribute is inlined into a function
1063that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
1064have an <tt>ssp</tt> attribute.</p></dd>
1065
1066<dt><tt>sspreq</tt></dt>
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1067<dd>This attribute indicates that the function should <em>always</em> emit a
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1068stack smashing protector. This overrides the <tt><a href="#ssp">ssp</a></tt>
Bill Wendlingbaa39d82008-11-26 19:19:05 +0000[diff] [blame]1069function attribute.
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1070
1071<p>If a function that has an <tt>sspreq</tt> attribute is inlined into a
1072function that doesn't have an <tt>sspreq</tt> attribute or which has
1073an <tt>ssp</tt> attribute, then the resulting function will have
1074an <tt>sspreq</tt> attribute.</p></dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1075</dl>
1076
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1077</div>
1078
1079<!-- ======================================================================= -->
1080<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1081 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1082</div>
1083
1084<div class="doc_text">
1085<p>
1086Modules may contain "module-level inline asm" blocks, which corresponds to the
1087GCC "file scope inline asm" blocks. These blocks are internally concatenated by
1088LLVM and treated as a single unit, but may be separated in the .ll file if
1089desired. The syntax is very simple:
1090</p>
1091
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1092<div class="doc_code">
1093<pre>
1094module asm "inline asm code goes here"
1095module asm "more can go here"
1096</pre>
1097</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1098
1099<p>The strings can contain any character by escaping non-printable characters.
1100 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
1101 for the number.
1102</p>
1103
1104<p>
1105 The inline asm code is simply printed to the machine code .s file when
1106 assembly code is generated.
1107</p>
1108</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1109
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1110<!-- ======================================================================= -->
1111<div class="doc_subsection">
1112 <a name="datalayout">Data Layout</a>
1113</div>
1114
1115<div class="doc_text">
1116<p>A module may specify a target specific data layout string that specifies how
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]1117data is to be laid out in memory. The syntax for the data layout is simply:</p>
1118<pre> target datalayout = "<i>layout specification</i>"</pre>
1119<p>The <i>layout specification</i> consists of a list of specifications
1120separated by the minus sign character ('-'). Each specification starts with a
1121letter and may include other information after the letter to define some
1122aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1123<dl>
1124 <dt><tt>E</tt></dt>
1125 <dd>Specifies that the target lays out data in big-endian form. That is, the
1126 bits with the most significance have the lowest address location.</dd>
1127 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1128 <dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1129 the bits with the least significance have the lowest address location.</dd>
1130 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1131 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
1132 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
1133 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
1134 too.</dd>
1135 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1136 <dd>This specifies the alignment for an integer type of a given bit
1137 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1138 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1139 <dd>This specifies the alignment for a vector type of a given bit
1140 <i>size</i>.</dd>
1141 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1142 <dd>This specifies the alignment for a floating point type of a given bit
1143 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1144 (double).</dd>
1145 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1146 <dd>This specifies the alignment for an aggregate type of a given bit
1147 <i>size</i>.</dd>
1148</dl>
1149<p>When constructing the data layout for a given target, LLVM starts with a
1150default set of specifications which are then (possibly) overriden by the
1151specifications in the <tt>datalayout</tt> keyword. The default specifications
1152are given in this list:</p>
1153<ul>
1154 <li><tt>E</tt> - big endian</li>
1155 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1156 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1157 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1158 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1159 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1160 <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]1161 alignment of 64-bits</li>
1162 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1163 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1164 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1165 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1166 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
1167</ul>
Chris Lattnerebec6782008-08-05 18:21:08 +0000[diff] [blame]1168<p>When LLVM is determining the alignment for a given type, it uses the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1169following rules:</p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1170<ol>
1171 <li>If the type sought is an exact match for one of the specifications, that
1172 specification is used.</li>
1173 <li>If no match is found, and the type sought is an integer type, then the
1174 smallest integer type that is larger than the bitwidth of the sought type is
1175 used. If none of the specifications are larger than the bitwidth then the the
1176 largest integer type is used. For example, given the default specifications
1177 above, the i7 type will use the alignment of i8 (next largest) while both
1178 i65 and i256 will use the alignment of i64 (largest specified).</li>
1179 <li>If no match is found, and the type sought is a vector type, then the
1180 largest vector type that is smaller than the sought vector type will be used
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1181 as a fall back. This happens because &lt;128 x double&gt; can be implemented
1182 in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1183</ol>
1184</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1185
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1186<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1187<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1188<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1189
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1190<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1191
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1192<p>The LLVM type system is one of the most important features of the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1193intermediate representation. Being typed enables a number of
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1194optimizations to be performed on the intermediate representation directly,
1195without having to do
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1196extra analyses on the side before the transformation. A strong type
1197system makes it easier to read the generated code and enables novel
1198analyses and transformations that are not feasible to perform on normal
1199three address code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1200
1201</div>
1202
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1203<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1204<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1205Classifications</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1206<div class="doc_text">
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1207<p>The types fall into a few useful
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1208classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1209
1210<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1211 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1212 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1213 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1214 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1215 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1216 </tr>
1217 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1218 <td><a href="#t_floating">floating point</a></td>
1219 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1220 </tr>
1221 <tr>
1222 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1223 <td><a href="#t_integer">integer</a>,
1224 <a href="#t_floating">floating point</a>,
1225 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1226 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1227 <a href="#t_struct">structure</a>,
1228 <a href="#t_array">array</a>,
Dan Gohmanade5faa2008-05-23 22:50:26 +0000[diff] [blame]1229 <a href="#t_label">label</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1230 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1231 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1232 <tr>
1233 <td><a href="#t_primitive">primitive</a></td>
1234 <td><a href="#t_label">label</a>,
1235 <a href="#t_void">void</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1236 <a href="#t_floating">floating point</a>.</td>
1237 </tr>
1238 <tr>
1239 <td><a href="#t_derived">derived</a></td>
1240 <td><a href="#t_integer">integer</a>,
1241 <a href="#t_array">array</a>,
1242 <a href="#t_function">function</a>,
1243 <a href="#t_pointer">pointer</a>,
1244 <a href="#t_struct">structure</a>,
1245 <a href="#t_pstruct">packed structure</a>,
1246 <a href="#t_vector">vector</a>,
1247 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1248 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1249 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1250 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1251</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1252
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1253<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1254most important. Values of these types are the only ones which can be
1255produced by instructions, passed as arguments, or used as operands to
Dan Gohmanc4b49eb2008-05-23 21:53:15 +0000[diff] [blame]1256instructions.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1257</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1258
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1259<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1260<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1261
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1262<div class="doc_text">
1263<p>The primitive types are the fundamental building blocks of the LLVM
1264system.</p>
1265
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1266</div>
1267
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1268<!-- _______________________________________________________________________ -->
1269<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1270
1271<div class="doc_text">
1272 <table>
1273 <tbody>
1274 <tr><th>Type</th><th>Description</th></tr>
1275 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1276 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1277 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1278 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1279 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1280 </tbody>
1281 </table>
1282</div>
1283
1284<!-- _______________________________________________________________________ -->
1285<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1286
1287<div class="doc_text">
1288<h5>Overview:</h5>
1289<p>The void type does not represent any value and has no size.</p>
1290
1291<h5>Syntax:</h5>
1292
1293<pre>
1294 void
1295</pre>
1296</div>
1297
1298<!-- _______________________________________________________________________ -->
1299<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1300
1301<div class="doc_text">
1302<h5>Overview:</h5>
1303<p>The label type represents code labels.</p>
1304
1305<h5>Syntax:</h5>
1306
1307<pre>
1308 label
1309</pre>
1310</div>
1311
1312
1313<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1314<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1315
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1316<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1317
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1318<p>The real power in LLVM comes from the derived types in the system.
1319This is what allows a programmer to represent arrays, functions,
1320pointers, and other useful types. Note that these derived types may be
1321recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1322
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1323</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1324
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1325<!-- _______________________________________________________________________ -->
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1326<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1327
1328<div class="doc_text">
1329
1330<h5>Overview:</h5>
1331<p>The integer type is a very simple derived type that simply specifies an
1332arbitrary bit width for the integer type desired. Any bit width from 1 bit to
13332^23-1 (about 8 million) can be specified.</p>
1334
1335<h5>Syntax:</h5>
1336
1337<pre>
1338 iN
1339</pre>
1340
1341<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1342value.</p>
1343
1344<h5>Examples:</h5>
1345<table class="layout">
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]1346 <tbody>
1347 <tr>
1348 <td><tt>i1</tt></td>
1349 <td>a single-bit integer.</td>
1350 </tr><tr>
1351 <td><tt>i32</tt></td>
1352 <td>a 32-bit integer.</td>
1353 </tr><tr>
1354 <td><tt>i1942652</tt></td>
1355 <td>a really big integer of over 1 million bits.</td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1356 </tr>
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]1357 </tbody>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1358</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1359
1360<p>Note that the code generator does not yet support large integer types
1361to be used as function return types. The specific limit on how large a
1362return type the code generator can currently handle is target-dependent;
1363currently it's often 64 bits for 32-bit targets and 128 bits for 64-bit
1364targets.</p>
1365
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1366</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1367
1368<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1369<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1370
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1371<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1372
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1373<h5>Overview:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1374
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1375<p>The array type is a very simple derived type that arranges elements
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1376sequentially in memory. The array type requires a size (number of
1377elements) and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1378
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1379<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1380
1381<pre>
1382 [&lt;# elements&gt; x &lt;elementtype&gt;]
1383</pre>
1384
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1385<p>The number of elements is a constant integer value; elementtype may
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1386be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1387
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1388<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1389<table class="layout">
1390 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1391 <td class="left"><tt>[40 x i32]</tt></td>
1392 <td class="left">Array of 40 32-bit integer values.</td>
1393 </tr>
1394 <tr class="layout">
1395 <td class="left"><tt>[41 x i32]</tt></td>
1396 <td class="left">Array of 41 32-bit integer values.</td>
1397 </tr>
1398 <tr class="layout">
1399 <td class="left"><tt>[4 x i8]</tt></td>
1400 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1401 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1402</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1403<p>Here are some examples of multidimensional arrays:</p>
1404<table class="layout">
1405 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1406 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1407 <td class="left">3x4 array of 32-bit integer values.</td>
1408 </tr>
1409 <tr class="layout">
1410 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1411 <td class="left">12x10 array of single precision floating point values.</td>
1412 </tr>
1413 <tr class="layout">
1414 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1415 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1416 </tr>
1417</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1418
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1419<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1420length array. Normally, accesses past the end of an array are undefined in
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1421LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1422As a special case, however, zero length arrays are recognized to be variable
1423length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1424type "{ i32, [0 x float]}", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1425
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1426<p>Note that the code generator does not yet support large aggregate types
1427to be used as function return types. The specific limit on how large an
1428aggregate return type the code generator can currently handle is
1429target-dependent, and also dependent on the aggregate element types.</p>
1430
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1431</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1432
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1433<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1434<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1435<div class="doc_text">
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1436
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1437<h5>Overview:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1438
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1439<p>The function type can be thought of as a function signature. It
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1440consists of a return type and a list of formal parameter types. The
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1441return 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]1442If 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]1443class types, and the struct must have at least one element.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1444
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1445<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1446
1447<pre>
1448 &lt;returntype list&gt; (&lt;parameter list&gt;)
1449</pre>
1450
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1451<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]1452specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1453which indicates that the function takes a variable number of arguments.
1454Variable argument functions can access their arguments with the <a
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1455 href="#int_varargs">variable argument handling intrinsic</a> functions.
1456'<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1457<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1458
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1459<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1460<table class="layout">
1461 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1462 <td class="left"><tt>i32 (i32)</tt></td>
1463 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1464 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1465 </tr><tr class="layout">
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]1466 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1467 </tt></td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1468 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1469 an <tt>i16</tt> that should be sign extended and a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1470 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1471 <tt>float</tt>.
1472 </td>
1473 </tr><tr class="layout">
1474 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1475 <td class="left">A vararg function that takes at least one
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1476 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1477 which returns an integer. This is the signature for <tt>printf</tt> in
1478 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1479 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1480 </tr><tr class="layout">
1481 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukmanb0a57aa2008-11-27 06:41:20 +0000[diff] [blame]1482 <td class="left">A function taking an <tt>i32</tt>, returning two
1483 <tt>i32</tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1484 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1485 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1486</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1487
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1488</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1489<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1490<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1491<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1492<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1493<p>The structure type is used to represent a collection of data members
1494together in memory. The packing of the field types is defined to match
1495the ABI of the underlying processor. The elements of a structure may
1496be any type that has a size.</p>
1497<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1498and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1499field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1500instruction.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1501<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1502<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1503<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1504<table class="layout">
1505 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1506 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1507 <td class="left">A triple of three <tt>i32</tt> values</td>
1508 </tr><tr class="layout">
1509 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1510 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1511 second element is a <a href="#t_pointer">pointer</a> to a
1512 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1513 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1514 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1515</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1516
1517<p>Note that the code generator does not yet support large aggregate types
1518to be used as function return types. The specific limit on how large an
1519aggregate return type the code generator can currently handle is
1520target-dependent, and also dependent on the aggregate element types.</p>
1521
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1522</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1523
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1524<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1525<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1526</div>
1527<div class="doc_text">
1528<h5>Overview:</h5>
1529<p>The packed structure type is used to represent a collection of data members
1530together in memory. There is no padding between fields. Further, the alignment
1531of a packed structure is 1 byte. The elements of a packed structure may
1532be any type that has a size.</p>
1533<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1534and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1535field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1536instruction.</p>
1537<h5>Syntax:</h5>
1538<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1539<h5>Examples:</h5>
1540<table class="layout">
1541 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1542 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1543 <td class="left">A triple of three <tt>i32</tt> values</td>
1544 </tr><tr class="layout">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1545 <td class="left">
1546<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1547 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1548 second element is a <a href="#t_pointer">pointer</a> to a
1549 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1550 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1551 </tr>
1552</table>
1553</div>
1554
1555<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1556<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1557<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1558<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1559<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]1560reference to another object, which must live in memory. Pointer types may have
1561an optional address space attribute defining the target-specific numbered
1562address space where the pointed-to object resides. The default address space is
1563zero.</p>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1564<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1565<pre> &lt;type&gt; *<br></pre>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1566<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1567<table class="layout">
1568 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]1569 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1570 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1571 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1572 </tr>
1573 <tr class="layout">
1574 <td class="left"><tt>i32 (i32 *) *</tt></td>
1575 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1576 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1577 <tt>i32</tt>.</td>
1578 </tr>
1579 <tr class="layout">
1580 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1581 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1582 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1583 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1584</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1585</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1586
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1587<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1588<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1589<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1590
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1591<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1592
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1593<p>A vector type is a simple derived type that represents a vector
1594of elements. Vector types are used when multiple primitive data
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1595are operated in parallel using a single instruction (SIMD).
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1596A vector type requires a size (number of
Chris Lattnerb8d172f2005-11-10 01:44:22 +0000[diff] [blame]1597elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1598of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1599considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1600
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1601<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1602
1603<pre>
1604 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1605</pre>
1606
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1607<p>The number of elements is a constant integer value; elementtype may
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1608be any integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1609
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1610<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1611
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1612<table class="layout">
1613 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1614 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1615 <td class="left">Vector of 4 32-bit integer values.</td>
1616 </tr>
1617 <tr class="layout">
1618 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1619 <td class="left">Vector of 8 32-bit floating-point values.</td>
1620 </tr>
1621 <tr class="layout">
1622 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1623 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1624 </tr>
1625</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1626
1627<p>Note that the code generator does not yet support large vector types
1628to be used as function return types. The specific limit on how large a
1629vector return type codegen can currently handle is target-dependent;
1630currently it's often a few times longer than a hardware vector register.</p>
1631
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1632</div>
1633
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1634<!-- _______________________________________________________________________ -->
1635<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1636<div class="doc_text">
1637
1638<h5>Overview:</h5>
1639
1640<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksen8ac04ff2007-10-14 00:34:53 +0000[diff] [blame]1641corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1642In LLVM, opaque types can eventually be resolved to any type (not just a
1643structure type).</p>
1644
1645<h5>Syntax:</h5>
1646
1647<pre>
1648 opaque
1649</pre>
1650
1651<h5>Examples:</h5>
1652
1653<table class="layout">
1654 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1655 <td class="left"><tt>opaque</tt></td>
1656 <td class="left">An opaque type.</td>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1657 </tr>
1658</table>
1659</div>
1660
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1661<!-- ======================================================================= -->
1662<div class="doc_subsection">
1663 <a name="t_uprefs">Type Up-references</a>
1664</div>
1665
1666<div class="doc_text">
1667<h5>Overview:</h5>
1668<p>
1669An "up reference" allows you to refer to a lexically enclosing type without
1670requiring it to have a name. For instance, a structure declaration may contain a
1671pointer to any of the types it is lexically a member of. Example of up
1672references (with their equivalent as named type declarations) include:</p>
1673
1674<pre>
1675 { \2 * } %x = type { %t* }
1676 { \2 }* %y = type { %y }*
1677 \1* %z = type %z*
1678</pre>
1679
1680<p>
1681An up reference is needed by the asmprinter for printing out cyclic types when
1682there is no declared name for a type in the cycle. Because the asmprinter does
1683not want to print out an infinite type string, it needs a syntax to handle
1684recursive types that have no names (all names are optional in llvm IR).
1685</p>
1686
1687<h5>Syntax:</h5>
1688<pre>
1689 \&lt;level&gt;
1690</pre>
1691
1692<p>
1693The level is the count of the lexical type that is being referred to.
1694</p>
1695
1696<h5>Examples:</h5>
1697
1698<table class="layout">
1699 <tr class="layout">
1700 <td class="left"><tt>\1*</tt></td>
1701 <td class="left">Self-referential pointer.</td>
1702 </tr>
1703 <tr class="layout">
1704 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
1705 <td class="left">Recursive structure where the upref refers to the out-most
1706 structure.</td>
1707 </tr>
1708</table>
1709</div>
1710
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1711
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1712<!-- *********************************************************************** -->
1713<div class="doc_section"> <a name="constants">Constants</a> </div>
1714<!-- *********************************************************************** -->
1715
1716<div class="doc_text">
1717
1718<p>LLVM has several different basic types of constants. This section describes
1719them all and their syntax.</p>
1720
1721</div>
1722
1723<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1724<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1725
1726<div class="doc_text">
1727
1728<dl>
1729 <dt><b>Boolean constants</b></dt>
1730
1731 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1732 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1733 </dd>
1734
1735 <dt><b>Integer constants</b></dt>
1736
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1737 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1738 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1739 integer types.
1740 </dd>
1741
1742 <dt><b>Floating point constants</b></dt>
1743
1744 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1745 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]1746 notation (see below). The assembler requires the exact decimal value of
1747 a floating-point constant. For example, the assembler accepts 1.25 but
1748 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1749 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1750
1751 <dt><b>Null pointer constants</b></dt>
1752
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1753 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1754 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1755
1756</dl>
1757
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1758<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1759of floating point constants. For example, the form '<tt>double
17600x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
17614.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1762(and the only time that they are generated by the disassembler) is when a
1763floating point constant must be emitted but it cannot be represented as a
1764decimal floating point number. For example, NaN's, infinities, and other
1765special values are represented in their IEEE hexadecimal format so that
1766assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1767
1768</div>
1769
1770<!-- ======================================================================= -->
1771<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1772</div>
1773
1774<div class="doc_text">
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]1775<p>Aggregate constants arise from aggregation of simple constants
1776and smaller aggregate constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1777
1778<dl>
1779 <dt><b>Structure constants</b></dt>
1780
1781 <dd>Structure constants are represented with notation similar to structure
1782 type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner64910ee2007-12-25 20:34:52 +0000[diff] [blame]1783 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1784 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]1785 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1786 types of elements must match those specified by the type.
1787 </dd>
1788
1789 <dt><b>Array constants</b></dt>
1790
1791 <dd>Array constants are represented with notation similar to array type
1792 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1793 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1794 constants must have <a href="#t_array">array type</a>, and the number and
1795 types of elements must match those specified by the type.
1796 </dd>
1797
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1798 <dt><b>Vector constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1799
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1800 <dd>Vector constants are represented with notation similar to vector type
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1801 definitions (a comma separated list of elements, surrounded by
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1802 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]1803 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1804 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1805 match those specified by the type.
1806 </dd>
1807
1808 <dt><b>Zero initialization</b></dt>
1809
1810 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1811 value to zero of <em>any</em> type, including scalar and aggregate types.
1812 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]1813 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1814 initializers.
1815 </dd>
1816</dl>
1817
1818</div>
1819
1820<!-- ======================================================================= -->
1821<div class="doc_subsection">
1822 <a name="globalconstants">Global Variable and Function Addresses</a>
1823</div>
1824
1825<div class="doc_text">
1826
1827<p>The addresses of <a href="#globalvars">global variables</a> and <a
1828href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1829constants. These constants are explicitly referenced when the <a
1830href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1831href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1832file:</p>
1833
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1834<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1835<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]1836@X = global i32 17
1837@Y = global i32 42
1838@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1839</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1840</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1841
1842</div>
1843
1844<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1845<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1846<div class="doc_text">
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1847 <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]1848 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1849 a constant is permitted.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1850
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1851 <p>Undefined values indicate to the compiler that the program is well defined
1852 no matter what value is used, giving the compiler more freedom to optimize.
1853 </p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1854</div>
1855
1856<!-- ======================================================================= -->
1857<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1858</div>
1859
1860<div class="doc_text">
1861
1862<p>Constant expressions are used to allow expressions involving other constants
1863to be used as constants. Constant expressions may be of any <a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1864href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1865that does not have side effects (e.g. load and call are not supported). The
1866following is the syntax for constant expressions:</p>
1867
1868<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1869 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1870 <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]1871 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1872
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1873 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1874 <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]1875 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]1876
1877 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1878 <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]1879 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]1880
1881 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1882 <dd>Truncate a floating point constant to another floating point type. The
1883 size of CST must be larger than the size of TYPE. Both types must be
1884 floating point.</dd>
1885
1886 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1887 <dd>Floating point extend a constant to another type. The size of CST must be
1888 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1889
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]1890 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1891 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1892 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1893 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1894 of the same number of elements. If the value won't fit in the integer type,
1895 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1896
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1897 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1898 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1899 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1900 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1901 of the same number of elements. If the value won't fit in the integer type,
1902 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1903
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1904 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1905 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1906 constant. TYPE must be a scalar or vector floating point type. CST must be of
1907 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1908 of the same number of elements. If the value won't fit in the floating point
1909 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1910
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1911 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1912 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1913 constant. TYPE must be a scalar or vector floating point type. CST must be of
1914 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1915 of the same number of elements. If the value won't fit in the floating point
1916 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1917
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1918 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1919 <dd>Convert a pointer typed constant to the corresponding integer constant
1920 TYPE must be an integer type. CST must be of pointer type. The CST value is
1921 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1922
1923 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1924 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1925 pointer type. CST must be of integer type. The CST value is zero extended,
1926 truncated, or unchanged to make it fit in a pointer size. This one is
1927 <i>really</i> dangerous!</dd>
1928
1929 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1930 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1931 identical (same number of bits). The conversion is done as if the CST value
1932 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]1933 with this operator, just the type. This can be used for conversion of
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1934 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]1935 pointers it is only valid to cast to another pointer type. It is not valid
1936 to bitcast to or from an aggregate type.
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1937 </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1938
1939 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1940
1941 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1942 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1943 instruction, the index list may have zero or more indexes, which are required
1944 to make sense for the type of "CSTPTR".</dd>
1945
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1946 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1947
1948 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1949 constants.</dd>
1950
1951 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1952 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1953
1954 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1955 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1956
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]1957 <dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
1958 <dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
1959
1960 <dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
1961 <dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
1962
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1963 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1964
1965 <dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]1966 operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1967
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1968 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1969
1970 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1971 operation</a> on constants.</dd>
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1972
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1973
1974 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1975
1976 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1977 operation</a> on constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1978
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1979 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1980
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1981 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1982 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1983 binary</a> operations. The constraints on operands are the same as those for
1984 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1985 values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1986</dl>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1987</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]1988
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1989<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1990<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1991<!-- *********************************************************************** -->
1992
1993<!-- ======================================================================= -->
1994<div class="doc_subsection">
1995<a name="inlineasm">Inline Assembler Expressions</a>
1996</div>
1997
1998<div class="doc_text">
1999
2000<p>
2001LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
2002Module-Level Inline Assembly</a>) through the use of a special value. This
2003value represents the inline assembler as a string (containing the instructions
2004to emit), a list of operand constraints (stored as a string), and a flag that
2005indicates whether or not the inline asm expression has side effects. An example
2006inline assembler expression is:
2007</p>
2008
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2009<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2010<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2011i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2012</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2013</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2014
2015<p>
2016Inline assembler expressions may <b>only</b> be used as the callee operand of
2017a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
2018</p>
2019
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2020<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2021<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2022%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]2023</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2024</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2025
2026<p>
2027Inline asms with side effects not visible in the constraint list must be marked
2028as having side effects. This is done through the use of the
2029'<tt>sideeffect</tt>' keyword, like so:
2030</p>
2031
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2032<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2033<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2034call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2035</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2036</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2037
2038<p>TODO: The format of the asm and constraints string still need to be
2039documented here. Constraints on what can be done (e.g. duplication, moving, etc
Chris Lattner4f993352008-10-04 18:36:02 +0000[diff] [blame]2040need to be documented). This is probably best done by reference to another
2041document that covers inline asm from a holistic perspective.
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2042</p>
2043
2044</div>
2045
2046<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2047<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
2048<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2049
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2050<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2051
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2052<p>The LLVM instruction set consists of several different
2053classifications of instructions: <a href="#terminators">terminator
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2054instructions</a>, <a href="#binaryops">binary instructions</a>,
2055<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2056 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
2057instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2058
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2059</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2060
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2061<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2062<div class="doc_subsection"> <a name="terminators">Terminator
2063Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2064
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2065<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2066
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2067<p>As mentioned <a href="#functionstructure">previously</a>, every
2068basic block in a program ends with a "Terminator" instruction, which
2069indicates which block should be executed after the current block is
2070finished. These terminator instructions typically yield a '<tt>void</tt>'
2071value: they produce control flow, not values (the one exception being
2072the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2073<p>There are six different terminator instructions: the '<a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2074 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
2075instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2076the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
2077 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
2078 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2079
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2080</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2081
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2082<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2083<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
2084Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2085<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2086<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2087<pre>
2088 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]2089 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2090</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2091
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2092<h5>Overview:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2093
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2094<p>The '<tt>ret</tt>' instruction is used to return control flow (and
2095optionally a value) from a function back to the caller.</p>
John Criswell4457dc92004-04-09 16:48:45 +0000[diff] [blame]2096<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2097returns a value and then causes control flow, and one that just causes
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2098control flow to occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2099
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2100<h5>Arguments:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2101
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2102<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
2103the return value. The type of the return value must be a
2104'<a href="#t_firstclass">first class</a>' type.</p>
2105
2106<p>A function is not <a href="#wellformed">well formed</a> if
2107it it has a non-void return type and contains a '<tt>ret</tt>'
2108instruction with no return value or a return value with a type that
2109does not match its type, or if it has a void return type and contains
2110a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2111
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2112<h5>Semantics:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2113
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2114<p>When the '<tt>ret</tt>' instruction is executed, control flow
2115returns back to the calling function's context. If the caller is a "<a
John Criswellfa081872004-06-25 15:16:57 +0000[diff] [blame]2116 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2117the instruction after the call. If the caller was an "<a
2118 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2119at the beginning of the "normal" destination block. If the instruction
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2120returns a value, that value shall set the call or invoke instruction's
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]2121return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2122
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2123<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2124
2125<pre>
2126 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2127 ret void <i>; Return from a void function</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2128 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]2129</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2130
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]2131<p>Note that the code generator does not yet fully support large
2132 return values. The specific sizes that are currently supported are
2133 dependent on the target. For integers, on 32-bit targets the limit
2134 is often 64 bits, and on 64-bit targets the limit is often 128 bits.
2135 For aggregate types, the current limits are dependent on the element
2136 types; for example targets are often limited to 2 total integer
2137 elements and 2 total floating-point elements.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2138
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2139</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2140<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2141<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2142<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2143<h5>Syntax:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2144<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]2145</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2146<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2147<p>The '<tt>br</tt>' instruction is used to cause control flow to
2148transfer to a different basic block in the current function. There are
2149two forms of this instruction, corresponding to a conditional branch
2150and an unconditional branch.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2151<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2152<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2153single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]2154unconditional form of the '<tt>br</tt>' instruction takes a single
2155'<tt>label</tt>' value as a target.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2156<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2157<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2158argument is evaluated. If the value is <tt>true</tt>, control flows
2159to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2160control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2161<h5>Example:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2162<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]2163 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]2164</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2165<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2166<div class="doc_subsubsection">
2167 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2168</div>
2169
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2170<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2171<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2172
2173<pre>
2174 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2175</pre>
2176
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2177<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2178
2179<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
2180several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2181instruction, allowing a branch to occur to one of many possible
2182destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2183
2184
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2185<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2186
2187<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
2188comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
2189an array of pairs of comparison value constants and '<tt>label</tt>'s. The
2190table is not allowed to contain duplicate constant entries.</p>
2191
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2192<h5>Semantics:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2193
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2194<p>The <tt>switch</tt> instruction specifies a table of values and
2195destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]2196table is searched for the given value. If the value is found, control flow is
2197transfered to the corresponding destination; otherwise, control flow is
2198transfered to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2199
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2200<h5>Implementation:</h5>
2201
2202<p>Depending on properties of the target machine and the particular
2203<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]2204ways. For example, it could be generated as a series of chained conditional
2205branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2206
2207<h5>Example:</h5>
2208
2209<pre>
2210 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2211 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2212 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2213
2214 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2215 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2216
2217 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2218 switch i32 %val, label %otherwise [ i32 0, label %onzero
2219 i32 1, label %onone
2220 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2221</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2222</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2223
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2224<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2225<div class="doc_subsubsection">
2226 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2227</div>
2228
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2229<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2230
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2231<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2232
2233<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2234 &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]2235 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2236</pre>
2237
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2238<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2239
2240<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
2241function, with the possibility of control flow transfer to either the
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2242'<tt>normal</tt>' label or the
2243'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2244"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
2245"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]2246href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]2247continued at the dynamically nearest "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2248
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2249<h5>Arguments:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2250
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2251<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2252
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2253<ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2254 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]2255 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2256 convention</a> the call should use. If none is specified, the call defaults
2257 to using C calling conventions.
2258 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2259
2260 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
2261 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
2262 and '<tt>inreg</tt>' attributes are valid here.</li>
2263
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2264 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
2265 function value being invoked. In most cases, this is a direct function
2266 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
2267 an arbitrary pointer to function value.
2268 </li>
2269
2270 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
2271 function to be invoked. </li>
2272
2273 <li>'<tt>function args</tt>': argument list whose types match the function
2274 signature argument types. If the function signature indicates the function
2275 accepts a variable number of arguments, the extra arguments can be
2276 specified. </li>
2277
2278 <li>'<tt>normal label</tt>': the label reached when the called function
2279 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
2280
2281 <li>'<tt>exception label</tt>': the label reached when a callee returns with
2282 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
2283
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2284 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2285 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2286 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2287</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2288
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2289<h5>Semantics:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2290
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2291<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2292href="#i_call">call</a></tt>' instruction in most regards. The primary
2293difference is that it establishes an association with a label, which is used by
2294the runtime library to unwind the stack.</p>
2295
2296<p>This instruction is used in languages with destructors to ensure that proper
2297cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2298exception. Additionally, this is important for implementation of
2299'<tt>catch</tt>' clauses in high-level languages that support them.</p>
2300
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2301<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2302<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2303 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2304 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2305 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2306 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2307</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2308</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2309
2310
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2311<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2312
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2313<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2314Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2315
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2316<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2317
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2318<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2319<pre>
2320 unwind
2321</pre>
2322
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2323<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2324
2325<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
2326at the first callee in the dynamic call stack which used an <a
2327href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
2328primarily used to implement exception handling.</p>
2329
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2330<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2331
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]2332<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2333immediately halt. The dynamic call stack is then searched for the first <a
2334href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
2335execution continues at the "exceptional" destination block specified by the
2336<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
2337dynamic call chain, undefined behavior results.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2338</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2339
2340<!-- _______________________________________________________________________ -->
2341
2342<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2343Instruction</a> </div>
2344
2345<div class="doc_text">
2346
2347<h5>Syntax:</h5>
2348<pre>
2349 unreachable
2350</pre>
2351
2352<h5>Overview:</h5>
2353
2354<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
2355instruction is used to inform the optimizer that a particular portion of the
2356code is not reachable. This can be used to indicate that the code after a
2357no-return function cannot be reached, and other facts.</p>
2358
2359<h5>Semantics:</h5>
2360
2361<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
2362</div>
2363
2364
2365
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2366<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2367<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2368<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2369<p>Binary operators are used to do most of the computation in a
Chris Lattner5a158142008-04-01 18:47:32 +0000[diff] [blame]2370program. They require two operands of the same type, execute an operation on them, and
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2371produce a single value. The operands might represent
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2372multiple 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]2373The result value has the same type as its operands.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2374<p>There are several different binary operators:</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2375</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2376<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2377<div class="doc_subsubsection">
2378 <a name="i_add">'<tt>add</tt>' Instruction</a>
2379</div>
2380
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2381<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2382
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2383<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2384
2385<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2386 &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]2387</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2388
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2389<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2390
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2391<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2392
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2393<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2394
2395<p>The two arguments to the '<tt>add</tt>' instruction must be <a
2396 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
2397 <a href="#t_vector">vector</a> values. Both arguments must have identical
2398 types.</p>
2399
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2400<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2401
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2402<p>The value produced is the integer or floating point sum of the two
2403operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2404
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2405<p>If an integer sum has unsigned overflow, the result returned is the
2406mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2407the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2408
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2409<p>Because LLVM integers use a two's complement representation, this
2410instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2411
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2412<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2413
2414<pre>
2415 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2416</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2417</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2418<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2419<div class="doc_subsubsection">
2420 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2421</div>
2422
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2423<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2424
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2425<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2426
2427<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2428 &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]2429</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2430
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2431<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2432
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2433<p>The '<tt>sub</tt>' instruction returns the difference of its two
2434operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2435
2436<p>Note that the '<tt>sub</tt>' instruction is used to represent the
2437'<tt>neg</tt>' instruction present in most other intermediate
2438representations.</p>
2439
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2440<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2441
2442<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
2443 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2444 or <a href="#t_vector">vector</a> values. Both arguments must have identical
2445 types.</p>
2446
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2447<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2448
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2449<p>The value produced is the integer or floating point difference of
2450the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2451
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2452<p>If an integer difference has unsigned overflow, the result returned is the
2453mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2454the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2455
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2456<p>Because LLVM integers use a two's complement representation, this
2457instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2458
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2459<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2460<pre>
2461 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2462 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2463</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2464</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2465
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2466<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2467<div class="doc_subsubsection">
2468 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2469</div>
2470
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2471<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2472
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2473<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2474<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]2475</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2476<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2477<p>The '<tt>mul</tt>' instruction returns the product of its two
2478operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2479
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2480<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2481
2482<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
2483href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2484or <a href="#t_vector">vector</a> values. Both arguments must have identical
2485types.</p>
2486
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2487<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2488
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2489<p>The value produced is the integer or floating point product of the
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2490two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2491
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2492<p>If the result of an integer multiplication has unsigned overflow,
2493the result returned is the mathematical result modulo
24942<sup>n</sup>, where n is the bit width of the result.</p>
2495<p>Because LLVM integers use a two's complement representation, and the
2496result is the same width as the operands, this instruction returns the
2497correct result for both signed and unsigned integers. If a full product
2498(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
2499should be sign-extended or zero-extended as appropriate to the
2500width of the full product.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2501<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2502<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]2503</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2504</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2505
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2506<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2507<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2508</a></div>
2509<div class="doc_text">
2510<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2511<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]2512</pre>
2513<h5>Overview:</h5>
2514<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2515operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2516
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2517<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2518
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2519<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2520<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2521values. Both arguments must have identical types.</p>
2522
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2523<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2524
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2525<p>The value produced is the unsigned integer quotient of the two operands.</p>
2526<p>Note that unsigned integer division and signed integer division are distinct
2527operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2528<p>Division by zero leads to undefined behavior.</p>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2529<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2530<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]2531</pre>
2532</div>
2533<!-- _______________________________________________________________________ -->
2534<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2535</a> </div>
2536<div class="doc_text">
2537<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2538<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2539 &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]2540</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2541
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2542<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2543
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2544<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2545operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2546
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2547<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2548
2549<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2550<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2551values. Both arguments must have identical types.</p>
2552
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2553<h5>Semantics:</h5>
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2554<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]2555<p>Note that signed integer division and unsigned integer division are distinct
2556operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2557<p>Division by zero leads to undefined behavior. Overflow also leads to
2558undefined behavior; this is a rare case, but can occur, for example,
2559by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2560<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2561<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]2562</pre>
2563</div>
2564<!-- _______________________________________________________________________ -->
2565<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2566Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2567<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2568<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2569<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2570 &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]2571</pre>
2572<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2573
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2574<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2575operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2576
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2577<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2578
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2579<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2580<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2581of floating point values. Both arguments must have identical types.</p>
2582
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2583<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2584
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2585<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2586
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2587<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2588
2589<pre>
2590 &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]2591</pre>
2592</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2593
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2594<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2595<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2596</div>
2597<div class="doc_text">
2598<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2599<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]2600</pre>
2601<h5>Overview:</h5>
2602<p>The '<tt>urem</tt>' instruction returns the remainder from the
2603unsigned division of its two arguments.</p>
2604<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2605<p>The two arguments to the '<tt>urem</tt>' instruction must be
2606<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2607values. Both arguments must have identical types.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2608<h5>Semantics:</h5>
2609<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2610This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2611<p>Note that unsigned integer remainder and signed integer remainder are
2612distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
2613<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2614<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2615<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]2616</pre>
2617
2618</div>
2619<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2620<div class="doc_subsubsection">
2621 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
2622</div>
2623
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2624<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2625
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2626<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2627
2628<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2629 &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]2630</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2631
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2632<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2633
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2634<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2635signed division of its two operands. This instruction can also take
2636<a href="#t_vector">vector</a> versions of the values in which case
2637the elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]2638
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2639<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2640
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2641<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2642<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2643values. Both arguments must have identical types.</p>
2644
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2645<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2646
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2647<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2648has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
2649operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2650a value. For more information about the difference, see <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2651 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2652Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencer64f5c6c2007-03-24 22:40:44 +0000[diff] [blame]2653please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2654Wikipedia: modulo operation</a>.</p>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2655<p>Note that signed integer remainder and unsigned integer remainder are
2656distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
2657<p>Taking the remainder of a division by zero leads to undefined behavior.
2658Overflow also leads to undefined behavior; this is a rare case, but can occur,
2659for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
2660(The remainder doesn't actually overflow, but this rule lets srem be
2661implemented using instructions that return both the result of the division
2662and the remainder.)</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2663<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2664<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]2665</pre>
2666
2667</div>
2668<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2669<div class="doc_subsubsection">
2670 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
2671
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2672<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2673
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2674<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2675<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]2676</pre>
2677<h5>Overview:</h5>
2678<p>The '<tt>frem</tt>' instruction returns the remainder from the
2679division of its two operands.</p>
2680<h5>Arguments:</h5>
2681<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2682<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2683of floating point values. Both arguments must have identical types.</p>
2684
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2685<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2686
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2687<p>This instruction returns the <i>remainder</i> of a division.
2688The remainder has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2689
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2690<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2691
2692<pre>
2693 &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]2694</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2695</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]2696
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2697<!-- ======================================================================= -->
2698<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2699Operations</a> </div>
2700<div class="doc_text">
2701<p>Bitwise binary operators are used to do various forms of
2702bit-twiddling in a program. They are generally very efficient
2703instructions and can commonly be strength reduced from other
Chris Lattnera73afe02008-04-01 18:45:27 +0000[diff] [blame]2704instructions. They require two operands of the same type, execute an operation on them,
2705and 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]2706</div>
2707
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2708<!-- _______________________________________________________________________ -->
2709<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2710Instruction</a> </div>
2711<div class="doc_text">
2712<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2713<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]2714</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2715
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2716<h5>Overview:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2717
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2718<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2719the left a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2720
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2721<h5>Arguments:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2722
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2723<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2724 href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2725type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2726
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2727<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2728
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2729<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
2730where 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]2731equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
2732If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
2733corresponding shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2734
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2735<h5>Example:</h5><pre>
2736 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2737 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2738 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2739 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]2740 &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]2741</pre>
2742</div>
2743<!-- _______________________________________________________________________ -->
2744<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2745Instruction</a> </div>
2746<div class="doc_text">
2747<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2748<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]2749</pre>
2750
2751<h5>Overview:</h5>
2752<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2753operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2754
2755<h5>Arguments:</h5>
2756<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2757<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]2758type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2759
2760<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2761
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2762<p>This instruction always performs a logical shift right operation. The most
2763significant bits of the result will be filled with zero bits after the
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2764shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
Mon P Wang01f8d092008-12-10 08:55:09 +0000[diff] [blame]2765the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
2766vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
2767amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2768
2769<h5>Example:</h5>
2770<pre>
2771 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2772 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2773 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2774 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2775 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]2776 &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]2777</pre>
2778</div>
2779
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2780<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2781<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2782Instruction</a> </div>
2783<div class="doc_text">
2784
2785<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2786<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]2787</pre>
2788
2789<h5>Overview:</h5>
2790<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2791operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2792
2793<h5>Arguments:</h5>
2794<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begeman5bc1ea02008-07-29 15:49:41 +0000[diff] [blame]2795<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]2796type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2797
2798<h5>Semantics:</h5>
2799<p>This instruction always performs an arithmetic shift right operation,
2800The most significant bits of the result will be filled with the sign bit
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2801of <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]2802larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
2803arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
2804corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2805
2806<h5>Example:</h5>
2807<pre>
2808 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2809 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2810 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2811 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2812 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]2813 &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]2814</pre>
2815</div>
2816
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2817<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2818<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2819Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2820
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2821<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2822
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2823<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2824
2825<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2826 &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]2827</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2828
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2829<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2830
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2831<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2832its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2833
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2834<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2835
2836<p>The two arguments to the '<tt>and</tt>' instruction must be
2837<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2838values. Both arguments must have identical types.</p>
2839
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2840<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2841<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2842<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2843<div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2844<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2845 <tbody>
2846 <tr>
2847 <td>In0</td>
2848 <td>In1</td>
2849 <td>Out</td>
2850 </tr>
2851 <tr>
2852 <td>0</td>
2853 <td>0</td>
2854 <td>0</td>
2855 </tr>
2856 <tr>
2857 <td>0</td>
2858 <td>1</td>
2859 <td>0</td>
2860 </tr>
2861 <tr>
2862 <td>1</td>
2863 <td>0</td>
2864 <td>0</td>
2865 </tr>
2866 <tr>
2867 <td>1</td>
2868 <td>1</td>
2869 <td>1</td>
2870 </tr>
2871 </tbody>
2872</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2873</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2874<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2875<pre>
2876 &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]2877 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2878 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2879</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2880</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2881<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2882<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2883<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2884<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2885<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]2886</pre>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2887<h5>Overview:</h5>
2888<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2889or of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2890<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2891
2892<p>The two arguments to the '<tt>or</tt>' instruction must be
2893<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2894values. Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2895<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2896<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2897<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2898<div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2899<table border="1" cellspacing="0" cellpadding="4">
2900 <tbody>
2901 <tr>
2902 <td>In0</td>
2903 <td>In1</td>
2904 <td>Out</td>
2905 </tr>
2906 <tr>
2907 <td>0</td>
2908 <td>0</td>
2909 <td>0</td>
2910 </tr>
2911 <tr>
2912 <td>0</td>
2913 <td>1</td>
2914 <td>1</td>
2915 </tr>
2916 <tr>
2917 <td>1</td>
2918 <td>0</td>
2919 <td>1</td>
2920 </tr>
2921 <tr>
2922 <td>1</td>
2923 <td>1</td>
2924 <td>1</td>
2925 </tr>
2926 </tbody>
2927</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2928</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2929<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2930<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2931 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2932 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2933</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2934</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2935<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2936<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2937Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2938<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2939<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2940<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]2941</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2942<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2943<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2944or of its two operands. The <tt>xor</tt> is used to implement the
2945"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2946<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2947<p>The two arguments to the '<tt>xor</tt>' instruction must be
2948<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2949values. Both arguments must have identical types.</p>
2950
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2951<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2952
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2953<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2954<p> </p>
Bill Wendlingc7e4c4d2008-09-07 10:29:20 +0000[diff] [blame]2955<div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2956<table border="1" cellspacing="0" cellpadding="4">
2957 <tbody>
2958 <tr>
2959 <td>In0</td>
2960 <td>In1</td>
2961 <td>Out</td>
2962 </tr>
2963 <tr>
2964 <td>0</td>
2965 <td>0</td>
2966 <td>0</td>
2967 </tr>
2968 <tr>
2969 <td>0</td>
2970 <td>1</td>
2971 <td>1</td>
2972 </tr>
2973 <tr>
2974 <td>1</td>
2975 <td>0</td>
2976 <td>1</td>
2977 </tr>
2978 <tr>
2979 <td>1</td>
2980 <td>1</td>
2981 <td>0</td>
2982 </tr>
2983 </tbody>
2984</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2985</div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2986<p> </p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2987<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2988<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2989 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2990 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2991 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2992</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2993</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2994
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2995<!-- ======================================================================= -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2996<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2997 <a name="vectorops">Vector Operations</a>
2998</div>
2999
3000<div class="doc_text">
3001
3002<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3003target-independent manner. These instructions cover the element-access and
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3004vector-specific operations needed to process vectors effectively. While LLVM
3005does directly support these vector operations, many sophisticated algorithms
3006will want to use target-specific intrinsics to take full advantage of a specific
3007target.</p>
3008
3009</div>
3010
3011<!-- _______________________________________________________________________ -->
3012<div class="doc_subsubsection">
3013 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
3014</div>
3015
3016<div class="doc_text">
3017
3018<h5>Syntax:</h5>
3019
3020<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3021 &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]3022</pre>
3023
3024<h5>Overview:</h5>
3025
3026<p>
3027The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3028element from a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3029</p>
3030
3031
3032<h5>Arguments:</h5>
3033
3034<p>
3035The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3036value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3037an index indicating the position from which to extract the element.
3038The index may be a variable.</p>
3039
3040<h5>Semantics:</h5>
3041
3042<p>
3043The result is a scalar of the same type as the element type of
3044<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
3045<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3046results are undefined.
3047</p>
3048
3049<h5>Example:</h5>
3050
3051<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3052 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3053</pre>
3054</div>
3055
3056
3057<!-- _______________________________________________________________________ -->
3058<div class="doc_subsubsection">
3059 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
3060</div>
3061
3062<div class="doc_text">
3063
3064<h5>Syntax:</h5>
3065
3066<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]3067 &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]3068</pre>
3069
3070<h5>Overview:</h5>
3071
3072<p>
3073The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3074element into a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3075</p>
3076
3077
3078<h5>Arguments:</h5>
3079
3080<p>
3081The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3082value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3083scalar value whose type must equal the element type of the first
3084operand. The third operand is an index indicating the position at
3085which to insert the value. The index may be a variable.</p>
3086
3087<h5>Semantics:</h5>
3088
3089<p>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]3090The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3091element values are those of <tt>val</tt> except at position
3092<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
3093exceeds the length of <tt>val</tt>, the results are undefined.
3094</p>
3095
3096<h5>Example:</h5>
3097
3098<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3099 %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]3100</pre>
3101</div>
3102
3103<!-- _______________________________________________________________________ -->
3104<div class="doc_subsubsection">
3105 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3106</div>
3107
3108<div class="doc_text">
3109
3110<h5>Syntax:</h5>
3111
3112<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3113 &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]3114</pre>
3115
3116<h5>Overview:</h5>
3117
3118<p>
3119The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3120from two input vectors, returning a vector with the same element type as
3121the input and length that is the same as the shuffle mask.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3122</p>
3123
3124<h5>Arguments:</h5>
3125
3126<p>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3127The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
3128with types that match each other. The third argument is a shuffle mask whose
3129element type is always 'i32'. The result of the instruction is a vector whose
3130length is the same as the shuffle mask and whose element type is the same as
3131the element type of the first two operands.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3132</p>
3133
3134<p>
3135The shuffle mask operand is required to be a constant vector with either
3136constant integer or undef values.
3137</p>
3138
3139<h5>Semantics:</h5>
3140
3141<p>
3142The elements of the two input vectors are numbered from left to right across
3143both of the vectors. The shuffle mask operand specifies, for each element of
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3144the result vector, which element of the two input vectors the result element
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3145gets. The element selector may be undef (meaning "don't care") and the second
3146operand may be undef if performing a shuffle from only one vector.
3147</p>
3148
3149<h5>Example:</h5>
3150
3151<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3152 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3153 &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]3154 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
3155 &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]3156 %result = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
3157 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
3158 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
3159 &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]3160</pre>
3161</div>
3162
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]3163
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3164<!-- ======================================================================= -->
3165<div class="doc_subsection">
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3166 <a name="aggregateops">Aggregate Operations</a>
3167</div>
3168
3169<div class="doc_text">
3170
3171<p>LLVM supports several instructions for working with aggregate values.
3172</p>
3173
3174</div>
3175
3176<!-- _______________________________________________________________________ -->
3177<div class="doc_subsubsection">
3178 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3179</div>
3180
3181<div class="doc_text">
3182
3183<h5>Syntax:</h5>
3184
3185<pre>
3186 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3187</pre>
3188
3189<h5>Overview:</h5>
3190
3191<p>
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3192The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3193or array element from an aggregate value.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3194</p>
3195
3196
3197<h5>Arguments:</h5>
3198
3199<p>
3200The first operand of an '<tt>extractvalue</tt>' instruction is a
3201value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3202type. The operands are constant indices to specify which value to extract
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3203in a similar manner as indices in a
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3204'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3205</p>
3206
3207<h5>Semantics:</h5>
3208
3209<p>
3210The result is the value at the position in the aggregate specified by
3211the index operands.
3212</p>
3213
3214<h5>Example:</h5>
3215
3216<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3217 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3218</pre>
3219</div>
3220
3221
3222<!-- _______________________________________________________________________ -->
3223<div class="doc_subsubsection">
3224 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3225</div>
3226
3227<div class="doc_text">
3228
3229<h5>Syntax:</h5>
3230
3231<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3232 &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]3233</pre>
3234
3235<h5>Overview:</h5>
3236
3237<p>
3238The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3239into a struct field or array element in an aggregate.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3240</p>
3241
3242
3243<h5>Arguments:</h5>
3244
3245<p>
3246The first operand of an '<tt>insertvalue</tt>' instruction is a
3247value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
3248The second operand is a first-class value to insert.
Dan Gohmanc4b49eb2008-05-23 21:53:15 +0000[diff] [blame]3249The following operands are constant indices
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3250indicating the position at which to insert the value in a similar manner as
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3251indices in a
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3252'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3253The value to insert must have the same type as the value identified
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3254by the indices.
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3255</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3256
3257<h5>Semantics:</h5>
3258
3259<p>
3260The result is an aggregate of the same type as <tt>val</tt>. Its
3261value is that of <tt>val</tt> except that the value at the position
Dan Gohmanc3dac5c2008-05-13 18:16:06 +0000[diff] [blame]3262specified by the indices is that of <tt>elt</tt>.
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3263</p>
3264
3265<h5>Example:</h5>
3266
3267<pre>
Dan Gohman52bb2db2008-06-23 15:26:37 +0000[diff] [blame]3268 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3269</pre>
3270</div>
3271
3272
3273<!-- ======================================================================= -->
3274<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3275 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3276</div>
3277
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3278<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3279
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3280<p>A key design point of an SSA-based representation is how it
3281represents memory. In LLVM, no memory locations are in SSA form, which
3282makes things very simple. This section describes how to read, write,
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3283allocate, and free memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3284
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3285</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3286
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3287<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3288<div class="doc_subsubsection">
3289 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3290</div>
3291
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3292<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3293
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3294<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3295
3296<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3297 &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]3298</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3299
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3300<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3301
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3302<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]3303heap and returns a pointer to it. The object is always allocated in the generic
3304address space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3305
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3306<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3307
3308<p>The '<tt>malloc</tt>' instruction allocates
3309<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswell6e4ca612004-02-24 16:13:56 +0000[diff] [blame]3310bytes of memory from the operating system and returns a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3311appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3312number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3313If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3314be aligned to at least that boundary. If not specified, or if zero, the target can
3315choose to align the allocation on any convenient boundary.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3316
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3317<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3318
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3319<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3320
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3321<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewycky02ff3082008-11-24 03:41:24 +0000[diff] [blame]3322a pointer is returned. The result of a zero byte allocation is undefined. The
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3323result is null if there is insufficient memory available.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3324
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3325<h5>Example:</h5>
3326
3327<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3328 %array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3329
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3330 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3331 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3332 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3333 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3334 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3335</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]3336
3337<p>Note that the code generator does not yet respect the
3338 alignment value.</p>
3339
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3340</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3341
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3342<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3343<div class="doc_subsubsection">
3344 <a name="i_free">'<tt>free</tt>' Instruction</a>
3345</div>
3346
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3347<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3348
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3349<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3350
3351<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3352 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3353</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3354
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3355<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3356
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3357<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]3358memory heap to be reallocated in the future.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3359
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3360<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3361
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3362<p>'<tt>value</tt>' shall be a pointer value that points to a value
3363that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
3364instruction.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3365
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3366<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3367
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3368<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattnere0db56d2008-04-19 22:41:32 +0000[diff] [blame]3369after this instruction executes. If the pointer is null, the operation
3370is a noop.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3371
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3372<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3373
3374<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3375 %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]3376 free [4 x i8]* %array
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3377</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3378</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3379
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3380<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3381<div class="doc_subsubsection">
3382 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3383</div>
3384
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3385<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3386
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3387<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3388
3389<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3390 &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]3391</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3392
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3393<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3394
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3395<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
3396currently executing function, to be automatically released when this function
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]3397returns to its caller. The object is always allocated in the generic address
3398space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3399
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3400<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3401
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3402<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3403bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3404appropriate type to the program. If "NumElements" is specified, it is the
3405number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3406If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greif1acd2ee2008-02-09 22:24:34 +0000[diff] [blame]3407to be aligned to at least that boundary. If not specified, or if zero, the target
3408can choose to align the allocation on any convenient boundary.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3409
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3410<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3411
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3412<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3413
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3414<p>Memory is allocated; a pointer is returned. The operation is undefiend if
3415there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3416memory is automatically released when the function returns. The '<tt>alloca</tt>'
3417instruction is commonly used to represent automatic variables that must
3418have an address available. When the function returns (either with the <tt><a
John Criswelldae2e932005-05-12 16:55:34 +0000[diff] [blame]3419 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]3420instructions), the memory is reclaimed. Allocating zero bytes
3421is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3422
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3423<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3424
3425<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3426 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
3427 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3428 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
3429 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3430</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3431</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3432
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3433<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3434<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3435Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3436<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3437<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]3438<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]3439<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3440<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3441<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3442<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]3443address from which to load. The pointer must point to a <a
Chris Lattnere53e5082004-06-03 22:57:15 +0000[diff] [blame]3444 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]3445marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3446the number or order of execution of this <tt>load</tt> with other
3447volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3448instructions. </p>
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3449<p>
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3450The optional constant "align" argument specifies the alignment of the operation
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3451(that is, the alignment of the memory address). A value of 0 or an
3452omitted "align" argument means that the operation has the preferential
3453alignment for the target. It is the responsibility of the code emitter
3454to ensure that the alignment information is correct. Overestimating
3455the alignment results in an undefined behavior. Underestimating the
3456alignment may produce less efficient code. An alignment of 1 is always
3457safe.
3458</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3459<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3460<p>The location of memory pointed to is loaded.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3461<h5>Examples:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3462<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3463 <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3464 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
3465 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3466</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3467</div>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3468<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3469<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3470Instruction</a> </div>
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]3471<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3472<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]3473<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
3474 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]3475</pre>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3476<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3477<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3478<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3479<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3480to 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]3481operand must be a pointer to the <a href="#t_firstclass">first class</a> type
3482of the '<tt>&lt;value&gt;</tt>'
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]3483operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3484optimizer is not allowed to modify the number or order of execution of
3485this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
3486 href="#i_store">store</a></tt> instructions.</p>
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3487<p>
Chris Lattner4316dec2008-04-02 00:38:26 +0000[diff] [blame]3488The optional constant "align" argument specifies the alignment of the operation
Chris Lattnera31d1d72008-01-06 21:04:43 +0000[diff] [blame]3489(that is, the alignment of the memory address). A value of 0 or an
3490omitted "align" argument means that the operation has the preferential
3491alignment for the target. It is the responsibility of the code emitter
3492to ensure that the alignment information is correct. Overestimating
3493the alignment results in an undefined behavior. Underestimating the
3494alignment may produce less efficient code. An alignment of 1 is always
3495safe.
3496</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3497<h5>Semantics:</h5>
3498<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
3499at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3500<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3501<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]3502 store i32 3, i32* %ptr <i>; yields {void}</i>
3503 %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]3504</pre>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3505</div>
3506
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3507<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3508<div class="doc_subsubsection">
3509 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3510</div>
3511
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3512<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3513<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3514<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3515 &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]3516</pre>
3517
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3518<h5>Overview:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3519
3520<p>
3521The '<tt>getelementptr</tt>' instruction is used to get the address of a
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3522subelement of an aggregate data structure. It performs address calculation only
3523and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3524
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3525<h5>Arguments:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3526
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3527<p>The first argument is always a pointer, and forms the basis of the
3528calculation. The remaining arguments are indices, that indicate which of the
3529elements of the aggregate object are indexed. The interpretation of each index
3530is dependent on the type being indexed into. The first index always indexes the
3531pointer value given as the first argument, the second index indexes a value of
3532the type pointed to (not necessarily the value directly pointed to, since the
3533first index can be non-zero), etc. The first type indexed into must be a pointer
3534value, subsequent types can be arrays, vectors and structs. Note that subsequent
3535types being indexed into can never be pointers, since that would require loading
3536the pointer before continuing calculation.</p>
3537
3538<p>The type of each index argument depends on the type it is indexing into.
3539When indexing into a (packed) structure, only <tt>i32</tt> integer
3540<b>constants</b> are allowed. When indexing into an array, pointer or vector,
3541only integers of 32 or 64 bits are allowed (also non-constants). 32-bit values
3542will be sign extended to 64-bits if required.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3543
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3544<p>For example, let's consider a C code fragment and how it gets
3545compiled to LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3546
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3547<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3548<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3549struct RT {
3550 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3551 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3552 char C;
3553};
3554struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3555 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3556 double Y;
3557 struct RT Z;
3558};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3559
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3560int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3561 return &amp;s[1].Z.B[5][13];
3562}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3563</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3564</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3565
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3566<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3567
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3568<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3569<pre>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]3570%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
3571%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3572
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3573define i32* %foo(%ST* %s) {
3574entry:
3575 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3576 ret i32* %reg
3577}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3578</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3579</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3580
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3581<h5>Semantics:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3582
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3583<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]3584type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3585}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3586the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3587i8 }</tt>' type, another structure. The third index indexes into the second
3588element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3589array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3590'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
3591to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3592
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3593<p>Note that it is perfectly legal to index partially through a
3594structure, returning a pointer to an inner element. Because of this,
3595the LLVM code for the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3596
3597<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3598 define i32* %foo(%ST* %s) {
3599 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3600 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3601 %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]3602 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3603 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
3604 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3605 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3606</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3607
3608<p>Note that it is undefined to access an array out of bounds: array and
3609pointer indexes must always be within the defined bounds of the array type.
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]3610The one exception for this rule is zero length arrays. These arrays are
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3611defined to be accessible as variable length arrays, which requires access
3612beyond the zero'th element.</p>
3613
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3614<p>The getelementptr instruction is often confusing. For some more insight
3615into how it works, see <a href="GetElementPtr.html">the getelementptr
3616FAQ</a>.</p>
3617
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3618<h5>Example:</h5>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3619
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3620<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3621 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3622 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
3623 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3624 %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]3625 <i>; yields i8*:eptr</i>
3626 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3627</pre>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3628</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3629
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3630<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3631<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3632</div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3633<div class="doc_text">
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3634<p>The instructions in this category are the conversion instructions (casting)
3635which all take a single operand and a type. They perform various bit conversions
3636on the operand.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3637</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3638
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3639<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3640<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3641 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
3642</div>
3643<div class="doc_text">
3644
3645<h5>Syntax:</h5>
3646<pre>
3647 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3648</pre>
3649
3650<h5>Overview:</h5>
3651<p>
3652The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
3653</p>
3654
3655<h5>Arguments:</h5>
3656<p>
3657The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
3658be 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]3659and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3660type. The bit size of <tt>value</tt> must be larger than the bit size of
3661<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3662
3663<h5>Semantics:</h5>
3664<p>
3665The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3666and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
3667larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
3668It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3669
3670<h5>Example:</h5>
3671<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3672 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3673 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
3674 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3675</pre>
3676</div>
3677
3678<!-- _______________________________________________________________________ -->
3679<div class="doc_subsubsection">
3680 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
3681</div>
3682<div class="doc_text">
3683
3684<h5>Syntax:</h5>
3685<pre>
3686 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3687</pre>
3688
3689<h5>Overview:</h5>
3690<p>The '<tt>zext</tt>' instruction zero extends its operand to type
3691<tt>ty2</tt>.</p>
3692
3693
3694<h5>Arguments:</h5>
3695<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]3696<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3697also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3698<tt>value</tt> must be smaller than the bit size of the destination type,
3699<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3700
3701<h5>Semantics:</h5>
3702<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]3703bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3704
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]3705<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]3706
3707<h5>Example:</h5>
3708<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3709 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3710 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3711</pre>
3712</div>
3713
3714<!-- _______________________________________________________________________ -->
3715<div class="doc_subsubsection">
3716 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3717</div>
3718<div class="doc_text">
3719
3720<h5>Syntax:</h5>
3721<pre>
3722 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3723</pre>
3724
3725<h5>Overview:</h5>
3726<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3727
3728<h5>Arguments:</h5>
3729<p>
3730The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3731<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3732also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3733<tt>value</tt> must be smaller than the bit size of the destination type,
3734<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3735
3736<h5>Semantics:</h5>
3737<p>
3738The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3739bit (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]3740the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3741
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3742<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]3743
3744<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3745<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3746 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3747 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3748</pre>
3749</div>
3750
3751<!-- _______________________________________________________________________ -->
3752<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3753 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3754</div>
3755
3756<div class="doc_text">
3757
3758<h5>Syntax:</h5>
3759
3760<pre>
3761 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3762</pre>
3763
3764<h5>Overview:</h5>
3765<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3766<tt>ty2</tt>.</p>
3767
3768
3769<h5>Arguments:</h5>
3770<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3771 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3772cast it to. The size of <tt>value</tt> must be larger than the size of
3773<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3774<i>no-op cast</i>.</p>
3775
3776<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3777<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3778<a href="#t_floating">floating point</a> type to a smaller
3779<a href="#t_floating">floating point</a> type. If the value cannot fit within
3780the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3781
3782<h5>Example:</h5>
3783<pre>
3784 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3785 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3786</pre>
3787</div>
3788
3789<!-- _______________________________________________________________________ -->
3790<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3791 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3792</div>
3793<div class="doc_text">
3794
3795<h5>Syntax:</h5>
3796<pre>
3797 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3798</pre>
3799
3800<h5>Overview:</h5>
3801<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3802floating point value.</p>
3803
3804<h5>Arguments:</h5>
3805<p>The '<tt>fpext</tt>' instruction takes a
3806<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3807and a <a href="#t_floating">floating point</a> type to cast it to. The source
3808type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3809
3810<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3811<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3812<a href="#t_floating">floating point</a> type to a larger
3813<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3814used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3815<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]3816
3817<h5>Example:</h5>
3818<pre>
3819 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3820 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3821</pre>
3822</div>
3823
3824<!-- _______________________________________________________________________ -->
3825<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]3826 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3827</div>
3828<div class="doc_text">
3829
3830<h5>Syntax:</h5>
3831<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3832 &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]3833</pre>
3834
3835<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3836<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3837unsigned integer equivalent of type <tt>ty2</tt>.
3838</p>
3839
3840<h5>Arguments:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3841<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]3842scalar or vector <a href="#t_floating">floating point</a> value, and a type
3843to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3844type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3845vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3846
3847<h5>Semantics:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3848<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3849<a href="#t_floating">floating point</a> operand into the nearest (rounding
3850towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3851the results are undefined.</p>
3852
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3853<h5>Example:</h5>
3854<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3855 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3856 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3857 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3858</pre>
3859</div>
3860
3861<!-- _______________________________________________________________________ -->
3862<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3863 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3864</div>
3865<div class="doc_text">
3866
3867<h5>Syntax:</h5>
3868<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3869 &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]3870</pre>
3871
3872<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3873<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3874<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]3875</p>
3876
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3877<h5>Arguments:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3878<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]3879scalar or vector <a href="#t_floating">floating point</a> value, and a type
3880to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3881type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3882vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3883
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3884<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3885<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3886<a href="#t_floating">floating point</a> operand into the nearest (rounding
3887towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3888the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3889
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3890<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3891<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3892 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3893 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3894 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3895</pre>
3896</div>
3897
3898<!-- _______________________________________________________________________ -->
3899<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3900 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3901</div>
3902<div class="doc_text">
3903
3904<h5>Syntax:</h5>
3905<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3906 &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]3907</pre>
3908
3909<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3910<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3911integer and converts that value to the <tt>ty2</tt> type.</p>
3912
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3913<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3914<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3915scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3916to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3917type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3918floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3919
3920<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3921<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3922integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3923the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3924
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3925<h5>Example:</h5>
3926<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3927 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3928 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3929</pre>
3930</div>
3931
3932<!-- _______________________________________________________________________ -->
3933<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3934 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3935</div>
3936<div class="doc_text">
3937
3938<h5>Syntax:</h5>
3939<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3940 &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]3941</pre>
3942
3943<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3944<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3945integer and converts that value to the <tt>ty2</tt> type.</p>
3946
3947<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3948<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3949scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3950to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3951type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3952floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3953
3954<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3955<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3956integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3957the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3958
3959<h5>Example:</h5>
3960<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3961 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]3962 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3963</pre>
3964</div>
3965
3966<!-- _______________________________________________________________________ -->
3967<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3968 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3969</div>
3970<div class="doc_text">
3971
3972<h5>Syntax:</h5>
3973<pre>
3974 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3975</pre>
3976
3977<h5>Overview:</h5>
3978<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3979the integer type <tt>ty2</tt>.</p>
3980
3981<h5>Arguments:</h5>
3982<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3983must 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]3984<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]3985
3986<h5>Semantics:</h5>
3987<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3988<tt>ty2</tt> by interpreting the pointer value as an integer and either
3989truncating or zero extending that value to the size of the integer type. If
3990<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3991<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]3992are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3993change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3994
3995<h5>Example:</h5>
3996<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3997 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3998 %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]3999</pre>
4000</div>
4001
4002<!-- _______________________________________________________________________ -->
4003<div class="doc_subsubsection">
4004 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
4005</div>
4006<div class="doc_text">
4007
4008<h5>Syntax:</h5>
4009<pre>
4010 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4011</pre>
4012
4013<h5>Overview:</h5>
4014<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
4015a pointer type, <tt>ty2</tt>.</p>
4016
4017<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4018<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4019value to cast, and a type to cast it to, which must be a
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4020<a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4021
4022<h5>Semantics:</h5>
4023<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
4024<tt>ty2</tt> by applying either a zero extension or a truncation depending on
4025the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
4026size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
4027the size of a pointer then a zero extension is done. If they are the same size,
4028nothing is done (<i>no-op cast</i>).</p>
4029
4030<h5>Example:</h5>
4031<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4032 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
4033 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
4034 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4035</pre>
4036</div>
4037
4038<!-- _______________________________________________________________________ -->
4039<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4040 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4041</div>
4042<div class="doc_text">
4043
4044<h5>Syntax:</h5>
4045<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4046 &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]4047</pre>
4048
4049<h5>Overview:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4050
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4051<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4052<tt>ty2</tt> without changing any bits.</p>
4053
4054<h5>Arguments:</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 takes a value to cast, which must be
Dan Gohman500233a2008-09-08 16:45:59 +0000[diff] [blame]4057a non-aggregate first class value, and a type to cast it to, which must also be
4058a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
4059<tt>value</tt>
Reid Spencer19b569f2007-01-09 20:08:58 +0000[diff] [blame]4060and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4061type is a pointer, the destination type must also be a pointer. This
4062instruction supports bitwise conversion of vectors to integers and to vectors
4063of other types (as long as they have the same size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4064
4065<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4066<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4067<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
4068this conversion. The conversion is done as if the <tt>value</tt> had been
4069stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
4070converted to other pointer types with this instruction. To convert pointers to
4071other types, use the <a href="#i_inttoptr">inttoptr</a> or
4072<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4073
4074<h5>Example:</h5>
4075<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4076 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4077 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4078 %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]4079</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4080</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4081
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4082<!-- ======================================================================= -->
4083<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
4084<div class="doc_text">
4085<p>The instructions in this category are the "miscellaneous"
4086instructions, which defy better classification.</p>
4087</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4088
4089<!-- _______________________________________________________________________ -->
4090<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4091</div>
4092<div class="doc_text">
4093<h5>Syntax:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4094<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]4095</pre>
4096<h5>Overview:</h5>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4097<p>The '<tt>icmp</tt>' instruction returns a boolean value or
4098a vector of boolean values based on comparison
4099of its two integer, integer vector, or pointer operands.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4100<h5>Arguments:</h5>
4101<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4102the condition code indicating the kind of comparison to perform. It is not
4103a value, just a keyword. The possible condition code are:
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4104</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4105<ol>
4106 <li><tt>eq</tt>: equal</li>
4107 <li><tt>ne</tt>: not equal </li>
4108 <li><tt>ugt</tt>: unsigned greater than</li>
4109 <li><tt>uge</tt>: unsigned greater or equal</li>
4110 <li><tt>ult</tt>: unsigned less than</li>
4111 <li><tt>ule</tt>: unsigned less or equal</li>
4112 <li><tt>sgt</tt>: signed greater than</li>
4113 <li><tt>sge</tt>: signed greater or equal</li>
4114 <li><tt>slt</tt>: signed less than</li>
4115 <li><tt>sle</tt>: signed less or equal</li>
4116</ol>
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]4117<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4118<a href="#t_pointer">pointer</a>
4119or integer <a href="#t_vector">vector</a> typed.
4120They must also be identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4121<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4122<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]4123the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4124yields 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]4125</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4126<ol>
4127 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
4128 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
4129 </li>
4130 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4131 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4132 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4133 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4134 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4135 <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]4136 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4137 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4138 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4139 <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]4140 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4141 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4142 <li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4143 <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]4144 <li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4145 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4146 <li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4147 <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]4148</ol>
4149<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4150values are compared as if they were integers.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4151<p>If the operands are integer vectors, then they are compared
4152element by element. The result is an <tt>i1</tt> vector with
4153the same number of elements as the values being compared.
4154Otherwise, the result is an <tt>i1</tt>.
4155</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4156
4157<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4158<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
4159 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4160 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4161 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4162 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4163 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4164</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4165
4166<p>Note that the code generator does not yet support vector types with
4167 the <tt>icmp</tt> instruction.</p>
4168
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4169</div>
4170
4171<!-- _______________________________________________________________________ -->
4172<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4173</div>
4174<div class="doc_text">
4175<h5>Syntax:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4176<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]4177</pre>
4178<h5>Overview:</h5>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4179<p>The '<tt>fcmp</tt>' instruction returns a boolean value
4180or vector of boolean values based on comparison
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4181of its operands.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4182<p>
4183If the operands are floating point scalars, then the result
4184type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
4185</p>
4186<p>If the operands are floating point vectors, then the result type
4187is a vector of boolean with the same number of elements as the
4188operands being compared.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4189<h5>Arguments:</h5>
4190<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4191the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4192a value, just a keyword. The possible condition code are:</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4193<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4194 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4195 <li><tt>oeq</tt>: ordered and equal</li>
4196 <li><tt>ogt</tt>: ordered and greater than </li>
4197 <li><tt>oge</tt>: ordered and greater than or equal</li>
4198 <li><tt>olt</tt>: ordered and less than </li>
4199 <li><tt>ole</tt>: ordered and less than or equal</li>
4200 <li><tt>one</tt>: ordered and not equal</li>
4201 <li><tt>ord</tt>: ordered (no nans)</li>
4202 <li><tt>ueq</tt>: unordered or equal</li>
4203 <li><tt>ugt</tt>: unordered or greater than </li>
4204 <li><tt>uge</tt>: unordered or greater than or equal</li>
4205 <li><tt>ult</tt>: unordered or less than </li>
4206 <li><tt>ule</tt>: unordered or less than or equal</li>
4207 <li><tt>une</tt>: unordered or not equal</li>
4208 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4209 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4210</ol>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4211<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer93a49852006-12-06 07:08:07 +0000[diff] [blame]4212<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4213<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
4214either a <a href="#t_floating">floating point</a> type
4215or a <a href="#t_vector">vector</a> of floating point type.
4216They must have identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4217<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4218<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4219according to the condition code given as <tt>cond</tt>.
4220If the operands are vectors, then the vectors are compared
4221element by element.
4222Each comparison performed
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4223always yields an <a href="#t_primitive">i1</a> result, as follows:</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4224<ol>
4225 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4226 <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]4227 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4228 <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]4229 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4230 <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]4231 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4232 <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]4233 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4234 <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]4235 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4236 <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]4237 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4238 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
4239 <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]4240 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4241 <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]4242 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4243 <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]4244 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4245 <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]4246 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4247 <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]4248 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4249 <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]4250 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4251 <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]4252 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4253</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4254
4255<h5>Example:</h5>
4256<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]4257 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4258 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4259 &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]4260</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4261
4262<p>Note that the code generator does not yet support vector types with
4263 the <tt>fcmp</tt> instruction.</p>
4264
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4265</div>
4266
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4267<!-- _______________________________________________________________________ -->
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4268<div class="doc_subsubsection">
4269 <a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
4270</div>
4271<div class="doc_text">
4272<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4273<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]4274</pre>
4275<h5>Overview:</h5>
4276<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
4277element-wise comparison of its two integer vector operands.</p>
4278<h5>Arguments:</h5>
4279<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
4280the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4281a value, just a keyword. The possible condition code are:</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4282<ol>
4283 <li><tt>eq</tt>: equal</li>
4284 <li><tt>ne</tt>: not equal </li>
4285 <li><tt>ugt</tt>: unsigned greater than</li>
4286 <li><tt>uge</tt>: unsigned greater or equal</li>
4287 <li><tt>ult</tt>: unsigned less than</li>
4288 <li><tt>ule</tt>: unsigned less or equal</li>
4289 <li><tt>sgt</tt>: signed greater than</li>
4290 <li><tt>sge</tt>: signed greater or equal</li>
4291 <li><tt>slt</tt>: signed less than</li>
4292 <li><tt>sle</tt>: signed less or equal</li>
4293</ol>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4294<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4295<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
4296<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4297<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4298according to the condition code given as <tt>cond</tt>. The comparison yields a
4299<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
4300identical type as the values being compared. The most significant bit in each
4301element is 1 if the element-wise comparison evaluates to true, and is 0
4302otherwise. All other bits of the result are undefined. The condition codes
4303are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4304instruction</a>.</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4305
4306<h5>Example:</h5>
4307<pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4308 &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>
4309 &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]4310</pre>
4311</div>
4312
4313<!-- _______________________________________________________________________ -->
4314<div class="doc_subsubsection">
4315 <a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
4316</div>
4317<div class="doc_text">
4318<h5>Syntax:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4319<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]4320<h5>Overview:</h5>
4321<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
4322element-wise comparison of its two floating point vector operands. The output
4323elements have the same width as the input elements.</p>
4324<h5>Arguments:</h5>
4325<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
4326the condition code indicating the kind of comparison to perform. It is not
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4327a value, just a keyword. The possible condition code are:</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4328<ol>
4329 <li><tt>false</tt>: no comparison, always returns false</li>
4330 <li><tt>oeq</tt>: ordered and equal</li>
4331 <li><tt>ogt</tt>: ordered and greater than </li>
4332 <li><tt>oge</tt>: ordered and greater than or equal</li>
4333 <li><tt>olt</tt>: ordered and less than </li>
4334 <li><tt>ole</tt>: ordered and less than or equal</li>
4335 <li><tt>one</tt>: ordered and not equal</li>
4336 <li><tt>ord</tt>: ordered (no nans)</li>
4337 <li><tt>ueq</tt>: unordered or equal</li>
4338 <li><tt>ugt</tt>: unordered or greater than </li>
4339 <li><tt>uge</tt>: unordered or greater than or equal</li>
4340 <li><tt>ult</tt>: unordered or less than </li>
4341 <li><tt>ule</tt>: unordered or less than or equal</li>
4342 <li><tt>une</tt>: unordered or not equal</li>
4343 <li><tt>uno</tt>: unordered (either nans)</li>
4344 <li><tt>true</tt>: no comparison, always returns true</li>
4345</ol>
4346<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
4347<a href="#t_floating">floating point</a> typed. They must also be identical
4348types.</p>
4349<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4350<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4351according to the condition code given as <tt>cond</tt>. The comparison yields a
4352<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
4353an identical number of elements as the values being compared, and each element
4354having identical with to the width of the floating point elements. The most
4355significant bit in each element is 1 if the element-wise comparison evaluates to
4356true, and is 0 otherwise. All other bits of the result are undefined. The
4357condition codes are evaluated identically to the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4358<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4359
4360<h5>Example:</h5>
4361<pre>
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]4362 <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0, i32 -1 &gt;</i>
4363 &lt;result&gt; = vfcmp oeq &lt;2 x float&gt; &lt; float 4, float 0 &gt;, &lt; float 5, float 0 &gt;
4364
4365 <i>; yields: result=&lt;2 x i64&gt; &lt; i64 -1, i64 0 &gt;</i>
4366 &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]4367</pre>
4368</div>
4369
4370<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4371<div class="doc_subsubsection">
4372 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4373</div>
4374
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4375<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4376
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4377<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4378
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4379<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
4380<h5>Overview:</h5>
4381<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
4382the SSA graph representing the function.</p>
4383<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4384
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4385<p>The type of the incoming values is specified with the first type
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4386field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
4387as arguments, with one pair for each predecessor basic block of the
4388current block. Only values of <a href="#t_firstclass">first class</a>
4389type may be used as the value arguments to the PHI node. Only labels
4390may be used as the label arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4391
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4392<p>There must be no non-phi instructions between the start of a basic
4393block and the PHI instructions: i.e. PHI instructions must be first in
4394a basic block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4395
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4396<h5>Semantics:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4397
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4398<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
4399specified by the pair corresponding to the predecessor basic block that executed
4400just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4401
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4402<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4403<pre>
4404Loop: ; Infinite loop that counts from 0 on up...
4405 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4406 %nextindvar = add i32 %indvar, 1
4407 br label %Loop
4408</pre>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4409</div>
4410
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4411<!-- _______________________________________________________________________ -->
4412<div class="doc_subsubsection">
4413 <a name="i_select">'<tt>select</tt>' Instruction</a>
4414</div>
4415
4416<div class="doc_text">
4417
4418<h5>Syntax:</h5>
4419
4420<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4421 &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>
4422
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4423 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4424</pre>
4425
4426<h5>Overview:</h5>
4427
4428<p>
4429The '<tt>select</tt>' instruction is used to choose one value based on a
4430condition, without branching.
4431</p>
4432
4433
4434<h5>Arguments:</h5>
4435
4436<p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4437The '<tt>select</tt>' instruction requires an 'i1' value or
4438a vector of 'i1' values indicating the
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4439condition, and two values of the same <a href="#t_firstclass">first class</a>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4440type. If the val1/val2 are vectors and
4441the condition is a scalar, then entire vectors are selected, not
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4442individual elements.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4443</p>
4444
4445<h5>Semantics:</h5>
4446
4447<p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4448If 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]4449value argument; otherwise, it returns the second value argument.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4450</p>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4451<p>
4452If the condition is a vector of i1, then the value arguments must
4453be vectors of the same size, and the selection is done element
4454by element.
4455</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4456
4457<h5>Example:</h5>
4458
4459<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4460 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4461</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4462
4463<p>Note that the code generator does not yet support conditions
4464 with vector type.</p>
4465
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4466</div>
4467
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]4468
4469<!-- _______________________________________________________________________ -->
4470<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4471 <a name="i_call">'<tt>call</tt>' Instruction</a>
4472</div>
4473
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4474<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4475
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4476<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4477<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]4478 &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]4479</pre>
4480
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4481<h5>Overview:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4482
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4483<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4484
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4485<h5>Arguments:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4486
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4487<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4488
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4489<ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4490 <li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4491 <p>The optional "tail" marker indicates whether the callee function accesses
4492 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4493 function call is eligible for tail call optimization. Note that calls may
4494 be marked "tail" even if they do not occur before a <a
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4495 href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4496 </li>
4497 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4498 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4499 convention</a> the call should use. If none is specified, the call defaults
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4500 to using C calling conventions.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4501 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4502
4503 <li>
4504 <p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4505 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
4506 and '<tt>inreg</tt>' attributes are valid here.</p>
4507 </li>
4508
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]4509 <li>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4510 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
4511 the type of the return value. Functions that return no value are marked
4512 <tt><a href="#t_void">void</a></tt>.</p>
4513 </li>
4514 <li>
4515 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
4516 value being invoked. The argument types must match the types implied by
4517 this signature. This type can be omitted if the function is not varargs
4518 and if the function type does not return a pointer to a function.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4519 </li>
4520 <li>
4521 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4522 be invoked. In most cases, this is a direct function invocation, but
4523 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4524 to function value.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4525 </li>
4526 <li>
4527 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencera7e302a2005-05-01 22:22:57 +0000[diff] [blame]4528 function signature argument types. All arguments must be of
4529 <a href="#t_firstclass">first class</a> type. If the function signature
4530 indicates the function accepts a variable number of arguments, the extra
4531 arguments can be specified.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4532 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4533 <li>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]4534 <p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4535 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
4536 '<tt>readnone</tt>' attributes are valid here.</p>
4537 </li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4538</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4539
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4540<h5>Semantics:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4541
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4542<p>The '<tt>call</tt>' instruction is used to cause control flow to
4543transfer to a specified function, with its incoming arguments bound to
4544the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
4545instruction in the called function, control flow continues with the
4546instruction after the function call, and the return value of the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4547function is bound to the result argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4548
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4549<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4550
4551<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4552 %retval = call i32 @test(i32 %argc)
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]4553 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4554 %X = tail call i32 @foo() <i>; yields i32</i>
4555 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4556 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]4557
4558 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4559 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]4560 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
4561 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]4562 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]4563 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4564</pre>
4565
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4566</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4567
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4568<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4569<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]4570 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4571</div>
4572
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4573<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4574
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4575<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4576
4577<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4578 &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]4579</pre>
4580
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4581<h5>Overview:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4582
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4583<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4584the "variable argument" area of a function call. It is used to implement the
4585<tt>va_arg</tt> macro in C.</p>
4586
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4587<h5>Arguments:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4588
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4589<p>This instruction takes a <tt>va_list*</tt> value and the type of
4590the argument. It returns a value of the specified argument type and
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4591increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4592actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4593
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4594<h5>Semantics:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4595
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4596<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
4597type from the specified <tt>va_list</tt> and causes the
4598<tt>va_list</tt> to point to the next argument. For more information,
4599see the variable argument handling <a href="#int_varargs">Intrinsic
4600Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4601
4602<p>It is legal for this instruction to be called in a function which does not
4603take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4604function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4605
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4606<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4607href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4608argument.</p>
4609
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4610<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4611
4612<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4613
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]4614<p>Note that the code generator does not yet fully support va_arg
4615 on many targets. Also, it does not currently support va_arg with
4616 aggregate types on any target.</p>
4617
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4618</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4619
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4620<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4621<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4622<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4623
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4624<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4625
4626<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4627well known names and semantics and are required to follow certain restrictions.
4628Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4629language that does not require changing all of the transformations in LLVM when
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]4630adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4631
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4632<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4633prefix is reserved in LLVM for intrinsic names; thus, function names may not
4634begin with this prefix. Intrinsic functions must always be external functions:
4635you cannot define the body of intrinsic functions. Intrinsic functions may
4636only be used in call or invoke instructions: it is illegal to take the address
4637of an intrinsic function. Additionally, because intrinsic functions are part
4638of the LLVM language, it is required if any are added that they be documented
4639here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4640
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4641<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
4642a family of functions that perform the same operation but on different data
4643types. Because LLVM can represent over 8 million different integer types,
4644overloading is used commonly to allow an intrinsic function to operate on any
4645integer type. One or more of the argument types or the result type can be
4646overloaded to accept any integer type. Argument types may also be defined as
4647exactly matching a previous argument's type or the result type. This allows an
4648intrinsic function which accepts multiple arguments, but needs all of them to
4649be of the same type, to only be overloaded with respect to a single argument or
4650the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4651
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4652<p>Overloaded intrinsics will have the names of its overloaded argument types
4653encoded into its function name, each preceded by a period. Only those types
4654which are overloaded result in a name suffix. Arguments whose type is matched
4655against another type do not. For example, the <tt>llvm.ctpop</tt> function can
4656take an integer of any width and returns an integer of exactly the same integer
4657width. This leads to a family of functions such as
4658<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
4659Only one type, the return type, is overloaded, and only one type suffix is
4660required. Because the argument's type is matched against the return type, it
4661does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4662
4663<p>To learn how to add an intrinsic function, please see the
4664<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4665</p>
4666
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4667</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4668
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4669<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4670<div class="doc_subsection">
4671 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
4672</div>
4673
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4674<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4675
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4676<p>Variable argument support is defined in LLVM with the <a
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]4677 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4678intrinsic functions. These functions are related to the similarly
4679named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4680
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4681<p>All of these functions operate on arguments that use a
4682target-specific value type "<tt>va_list</tt>". The LLVM assembly
4683language reference manual does not define what this type is, so all
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4684transformations should be prepared to handle these functions regardless of
4685the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4686
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]4687<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]4688instruction and the variable argument handling intrinsic functions are
4689used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4690
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4691<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4692<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4693define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4694 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4695 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4696 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4697 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4698
4699 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4700 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4701
4702 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4703 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4704 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4705 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4706 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4707
4708 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4709 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4710 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4711}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4712
4713declare void @llvm.va_start(i8*)
4714declare void @llvm.va_copy(i8*, i8*)
4715declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4716</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4717</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4718
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4719</div>
4720
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4721<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4722<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4723 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4724</div>
4725
4726
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4727<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4728<h5>Syntax:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4729<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4730<h5>Overview:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4731<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4732<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
4733href="#i_va_arg">va_arg</a></tt>.</p>
4734
4735<h5>Arguments:</h5>
4736
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4737<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]4738
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4739<h5>Semantics:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4740
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4741<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]4742macro available in C. In a target-dependent way, it initializes the
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4743<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]4744<tt>va_arg</tt> will produce the first variable argument passed to the function.
4745Unlike 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]4746last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4747
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4748</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4749
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4750<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4751<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4752 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4753</div>
4754
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4755<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4756<h5>Syntax:</h5>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4757<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4758<h5>Overview:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4759
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4760<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4761which 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]4762or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4763
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4764<h5>Arguments:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4765
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4766<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]4767
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4768<h5>Semantics:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4769
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4770<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]4771macro available in C. In a target-dependent way, it destroys the
4772<tt>va_list</tt> element to which the argument points. Calls to <a
4773href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
4774<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
4775<tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4776
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4777</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4778
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4779<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4780<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4781 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4782</div>
4783
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4784<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4785
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4786<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4787
4788<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4789 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4790</pre>
4791
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4792<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4793
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4794<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
4795from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4796
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4797<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4798
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4799<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]4800The 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]4801
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4802
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4803<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4804
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4805<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
4806macro available in C. In a target-dependent way, it copies the source
4807<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
4808intrinsic is necessary because the <tt><a href="#int_va_start">
4809llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
4810example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4811
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4812</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4813
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4814<!-- ======================================================================= -->
4815<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4816 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
4817</div>
4818
4819<div class="doc_text">
4820
4821<p>
4822LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]4823Collection</a> (GC) requires the implementation and generation of these
4824intrinsics.
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4825These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4826stack</a>, as well as garbage collector implementations that require <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4827href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4828Front-ends for type-safe garbage collected languages should generate these
4829intrinsics to make use of the LLVM garbage collectors. For more details, see <a
4830href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
4831</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]4832
4833<p>The garbage collection intrinsics only operate on objects in the generic
4834 address space (address space zero).</p>
4835
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4836</div>
4837
4838<!-- _______________________________________________________________________ -->
4839<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4840 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4841</div>
4842
4843<div class="doc_text">
4844
4845<h5>Syntax:</h5>
4846
4847<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4848 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4849</pre>
4850
4851<h5>Overview:</h5>
4852
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]4853<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]4854the code generator, and allows some metadata to be associated with it.</p>
4855
4856<h5>Arguments:</h5>
4857
4858<p>The first argument specifies the address of a stack object that contains the
4859root pointer. The second pointer (which must be either a constant or a global
4860value address) contains the meta-data to be associated with the root.</p>
4861
4862<h5>Semantics:</h5>
4863
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]4864<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]4865location. At compile-time, the code generator generates information to allow
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4866the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
4867intrinsic may only be used in a function which <a href="#gc">specifies a GC
4868algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4869
4870</div>
4871
4872
4873<!-- _______________________________________________________________________ -->
4874<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4875 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4876</div>
4877
4878<div class="doc_text">
4879
4880<h5>Syntax:</h5>
4881
4882<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4883 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4884</pre>
4885
4886<h5>Overview:</h5>
4887
4888<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4889locations, allowing garbage collector implementations that require read
4890barriers.</p>
4891
4892<h5>Arguments:</h5>
4893
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4894<p>The second argument is the address to read from, which should be an address
4895allocated from the garbage collector. The first object is a pointer to the
4896start of the referenced object, if needed by the language runtime (otherwise
4897null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4898
4899<h5>Semantics:</h5>
4900
4901<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4902instruction, but may be replaced with substantially more complex code by the
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4903garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
4904may only be used in a function which <a href="#gc">specifies a GC
4905algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4906
4907</div>
4908
4909
4910<!-- _______________________________________________________________________ -->
4911<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4912 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4913</div>
4914
4915<div class="doc_text">
4916
4917<h5>Syntax:</h5>
4918
4919<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4920 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4921</pre>
4922
4923<h5>Overview:</h5>
4924
4925<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4926locations, allowing garbage collector implementations that require write
4927barriers (such as generational or reference counting collectors).</p>
4928
4929<h5>Arguments:</h5>
4930
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4931<p>The first argument is the reference to store, the second is the start of the
4932object to store it to, and the third is the address of the field of Obj to
4933store to. If the runtime does not require a pointer to the object, Obj may be
4934null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4935
4936<h5>Semantics:</h5>
4937
4938<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4939instruction, but may be replaced with substantially more complex code by the
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4940garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
4941may only be used in a function which <a href="#gc">specifies a GC
4942algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4943
4944</div>
4945
4946
4947
4948<!-- ======================================================================= -->
4949<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4950 <a name="int_codegen">Code Generator Intrinsics</a>
4951</div>
4952
4953<div class="doc_text">
4954<p>
4955These intrinsics are provided by LLVM to expose special features that may only
4956be implemented with code generator support.
4957</p>
4958
4959</div>
4960
4961<!-- _______________________________________________________________________ -->
4962<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4963 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4964</div>
4965
4966<div class="doc_text">
4967
4968<h5>Syntax:</h5>
4969<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4970 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4971</pre>
4972
4973<h5>Overview:</h5>
4974
4975<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4976The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4977target-specific value indicating the return address of the current function
4978or one of its callers.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4979</p>
4980
4981<h5>Arguments:</h5>
4982
4983<p>
4984The argument to this intrinsic indicates which function to return the address
4985for. Zero indicates the calling function, one indicates its caller, etc. The
4986argument is <b>required</b> to be a constant integer value.
4987</p>
4988
4989<h5>Semantics:</h5>
4990
4991<p>
4992The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4993the return address of the specified call frame, or zero if it cannot be
4994identified. The value returned by this intrinsic is likely to be incorrect or 0
4995for arguments other than zero, so it should only be used for debugging purposes.
4996</p>
4997
4998<p>
4999Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]5000aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5001source-language caller.
5002</p>
5003</div>
5004
5005
5006<!-- _______________________________________________________________________ -->
5007<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5008 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5009</div>
5010
5011<div class="doc_text">
5012
5013<h5>Syntax:</h5>
5014<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5015 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5016</pre>
5017
5018<h5>Overview:</h5>
5019
5020<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]5021The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5022target-specific frame pointer value for the specified stack frame.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5023</p>
5024
5025<h5>Arguments:</h5>
5026
5027<p>
5028The argument to this intrinsic indicates which function to return the frame
5029pointer for. Zero indicates the calling function, one indicates its caller,
5030etc. The argument is <b>required</b> to be a constant integer value.
5031</p>
5032
5033<h5>Semantics:</h5>
5034
5035<p>
5036The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
5037the frame address of the specified call frame, or zero if it cannot be
5038identified. The value returned by this intrinsic is likely to be incorrect or 0
5039for arguments other than zero, so it should only be used for debugging purposes.
5040</p>
5041
5042<p>
5043Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]5044aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5045source-language caller.
5046</p>
5047</div>
5048
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5049<!-- _______________________________________________________________________ -->
5050<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5051 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5052</div>
5053
5054<div class="doc_text">
5055
5056<h5>Syntax:</h5>
5057<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5058 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5059</pre>
5060
5061<h5>Overview:</h5>
5062
5063<p>
5064The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5065the function stack, for use with <a href="#int_stackrestore">
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5066<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
5067features like scoped automatic variable sized arrays in C99.
5068</p>
5069
5070<h5>Semantics:</h5>
5071
5072<p>
5073This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5074href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5075<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
5076<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
5077state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
5078practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
5079that were allocated after the <tt>llvm.stacksave</tt> was executed.
5080</p>
5081
5082</div>
5083
5084<!-- _______________________________________________________________________ -->
5085<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5086 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5087</div>
5088
5089<div class="doc_text">
5090
5091<h5>Syntax:</h5>
5092<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5093 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5094</pre>
5095
5096<h5>Overview:</h5>
5097
5098<p>
5099The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5100the function stack to the state it was in when the corresponding <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5101href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5102useful for implementing language features like scoped automatic variable sized
5103arrays in C99.
5104</p>
5105
5106<h5>Semantics:</h5>
5107
5108<p>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5109See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5110</p>
5111
5112</div>
5113
5114
5115<!-- _______________________________________________________________________ -->
5116<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5117 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5118</div>
5119
5120<div class="doc_text">
5121
5122<h5>Syntax:</h5>
5123<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5124 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]5125</pre>
5126
5127<h5>Overview:</h5>
5128
5129
5130<p>
5131The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5132a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
5133no
5134effect on the behavior of the program but can change its performance
Chris Lattner2a615362005-02-28 19:47:14 +0000[diff] [blame]5135characteristics.
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5136</p>
5137
5138<h5>Arguments:</h5>
5139
5140<p>
5141<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
5142determining if the fetch should be for a read (0) or write (1), and
5143<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattneraeffb4a2005-03-07 20:31:38 +0000[diff] [blame]5144locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5145<tt>locality</tt> arguments must be constant integers.
5146</p>
5147
5148<h5>Semantics:</h5>
5149
5150<p>
5151This intrinsic does not modify the behavior of the program. In particular,
5152prefetches cannot trap and do not produce a value. On targets that support this
5153intrinsic, the prefetch can provide hints to the processor cache for better
5154performance.
5155</p>
5156
5157</div>
5158
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5159<!-- _______________________________________________________________________ -->
5160<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5161 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5162</div>
5163
5164<div class="doc_text">
5165
5166<h5>Syntax:</h5>
5167<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5168 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5169</pre>
5170
5171<h5>Overview:</h5>
5172
5173
5174<p>
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5175The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5176(PC) in a region of
5177code to simulators and other tools. The method is target specific, but it is
5178expected that the marker will use exported symbols to transmit the PC of the
5179marker.
5180The marker makes no guarantees that it will remain with any specific instruction
5181after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb3e7afd2006-03-24 07:16:10 +0000[diff] [blame]5182optimizations. The intended use is to be inserted after optimizations to allow
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5183correlations of simulation runs.
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5184</p>
5185
5186<h5>Arguments:</h5>
5187
5188<p>
5189<tt>id</tt> is a numerical id identifying the marker.
5190</p>
5191
5192<h5>Semantics:</h5>
5193
5194<p>
5195This intrinsic does not modify the behavior of the program. Backends that do not
5196support this intrinisic may ignore it.
5197</p>
5198
5199</div>
5200
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5201<!-- _______________________________________________________________________ -->
5202<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5203 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5204</div>
5205
5206<div class="doc_text">
5207
5208<h5>Syntax:</h5>
5209<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5210 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5211</pre>
5212
5213<h5>Overview:</h5>
5214
5215
5216<p>
5217The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5218counter register (or similar low latency, high accuracy clocks) on those targets
5219that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
5220As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
5221should only be used for small timings.
5222</p>
5223
5224<h5>Semantics:</h5>
5225
5226<p>
5227When directly supported, reading the cycle counter should not modify any memory.
5228Implementations are allowed to either return a application specific value or a
5229system wide value. On backends without support, this is lowered to a constant 0.
5230</p>
5231
5232</div>
5233
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5234<!-- ======================================================================= -->
5235<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5236 <a name="int_libc">Standard C Library Intrinsics</a>
5237</div>
5238
5239<div class="doc_text">
5240<p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5241LLVM provides intrinsics for a few important standard C library functions.
5242These intrinsics allow source-language front-ends to pass information about the
5243alignment of the pointer arguments to the code generator, providing opportunity
5244for more efficient code generation.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5245</p>
5246
5247</div>
5248
5249<!-- _______________________________________________________________________ -->
5250<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5251 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5252</div>
5253
5254<div class="doc_text">
5255
5256<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5257<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
5258width. Not all targets support all bit widths however.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5259<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5260 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5261 i8 &lt;len&gt;, i32 &lt;align&gt;)
5262 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5263 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5264 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5265 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5266 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5267 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5268</pre>
5269
5270<h5>Overview:</h5>
5271
5272<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5273The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5274location to the destination location.
5275</p>
5276
5277<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5278Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5279intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5280</p>
5281
5282<h5>Arguments:</h5>
5283
5284<p>
5285The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5286the source. The third argument is an integer argument
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5287specifying the number of bytes to copy, and the fourth argument is the alignment
5288of the source and destination locations.
5289</p>
5290
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5291<p>
5292If 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]5293the caller guarantees that both the source and destination pointers are aligned
5294to that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5295</p>
5296
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5297<h5>Semantics:</h5>
5298
5299<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5300The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5301location to the destination location, which are not allowed to overlap. It
5302copies "len" bytes of memory over. If the argument is known to be aligned to
5303some boundary, this can be specified as the fourth argument, otherwise it should
5304be set to 0 or 1.
5305</p>
5306</div>
5307
5308
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5309<!-- _______________________________________________________________________ -->
5310<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5311 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5312</div>
5313
5314<div class="doc_text">
5315
5316<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5317<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
5318width. Not all targets support all bit widths however.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5319<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5320 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5321 i8 &lt;len&gt;, i32 &lt;align&gt;)
5322 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5323 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5324 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5325 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5326 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5327 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5328</pre>
5329
5330<h5>Overview:</h5>
5331
5332<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5333The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
5334location to the destination location. It is similar to the
Chris Lattner4b2cbcf2008-01-06 19:51:52 +0000[diff] [blame]5335'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5336</p>
5337
5338<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5339Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5340intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5341</p>
5342
5343<h5>Arguments:</h5>
5344
5345<p>
5346The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5347the source. The third argument is an integer argument
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5348specifying the number of bytes to copy, and the fourth argument is the alignment
5349of the source and destination locations.
5350</p>
5351
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5352<p>
5353If 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]5354the caller guarantees that the source and destination pointers are aligned to
5355that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5356</p>
5357
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5358<h5>Semantics:</h5>
5359
5360<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5361The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5362location to the destination location, which may overlap. It
5363copies "len" bytes of memory over. If the argument is known to be aligned to
5364some boundary, this can be specified as the fourth argument, otherwise it should
5365be set to 0 or 1.
5366</p>
5367</div>
5368
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5369
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5370<!-- _______________________________________________________________________ -->
5371<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5372 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5373</div>
5374
5375<div class="doc_text">
5376
5377<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5378<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
5379width. Not all targets support all bit widths however.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5380<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5381 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5382 i8 &lt;len&gt;, i32 &lt;align&gt;)
5383 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5384 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5385 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5386 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5387 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5388 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5389</pre>
5390
5391<h5>Overview:</h5>
5392
5393<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5394The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5395byte value.
5396</p>
5397
5398<p>
5399Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
5400does not return a value, and takes an extra alignment argument.
5401</p>
5402
5403<h5>Arguments:</h5>
5404
5405<p>
5406The first argument is a pointer to the destination to fill, the second is the
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5407byte value to fill it with, the third argument is an integer
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5408argument specifying the number of bytes to fill, and the fourth argument is the
5409known alignment of destination location.
5410</p>
5411
5412<p>
5413If 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]5414the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5415</p>
5416
5417<h5>Semantics:</h5>
5418
5419<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]5420The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
5421the
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5422destination location. If the argument is known to be aligned to some boundary,
5423this can be specified as the fourth argument, otherwise it should be set to 0 or
54241.
5425</p>
5426</div>
5427
5428
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5429<!-- _______________________________________________________________________ -->
5430<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5431 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5432</div>
5433
5434<div class="doc_text">
5435
5436<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5437<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]5438floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5439types however.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5440<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5441 declare float @llvm.sqrt.f32(float %Val)
5442 declare double @llvm.sqrt.f64(double %Val)
5443 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5444 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5445 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5446</pre>
5447
5448<h5>Overview:</h5>
5449
5450<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5451The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5452returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5453<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner103e2d72008-01-29 07:00:44 +0000[diff] [blame]5454negative numbers other than -0.0 (which allows for better optimization, because
5455there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
5456defined to return -0.0 like IEEE sqrt.
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5457</p>
5458
5459<h5>Arguments:</h5>
5460
5461<p>
5462The argument and return value are floating point numbers of the same type.
5463</p>
5464
5465<h5>Semantics:</h5>
5466
5467<p>
Dan Gohmand6257fe2007-07-16 14:37:41 +0000[diff] [blame]5468This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5469floating point number.
5470</p>
5471</div>
5472
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5473<!-- _______________________________________________________________________ -->
5474<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5475 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5476</div>
5477
5478<div class="doc_text">
5479
5480<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5481<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5482floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5483types however.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5484<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5485 declare float @llvm.powi.f32(float %Val, i32 %power)
5486 declare double @llvm.powi.f64(double %Val, i32 %power)
5487 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5488 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5489 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5490</pre>
5491
5492<h5>Overview:</h5>
5493
5494<p>
5495The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5496specified (positive or negative) power. The order of evaluation of
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5497multiplications is not defined. When a vector of floating point type is
5498used, the second argument remains a scalar integer value.
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5499</p>
5500
5501<h5>Arguments:</h5>
5502
5503<p>
5504The second argument is an integer power, and the first is a value to raise to
5505that power.
5506</p>
5507
5508<h5>Semantics:</h5>
5509
5510<p>
5511This function returns the first value raised to the second power with an
5512unspecified sequence of rounding operations.</p>
5513</div>
5514
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5515<!-- _______________________________________________________________________ -->
5516<div class="doc_subsubsection">
5517 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5518</div>
5519
5520<div class="doc_text">
5521
5522<h5>Syntax:</h5>
5523<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5524floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5525types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5526<pre>
5527 declare float @llvm.sin.f32(float %Val)
5528 declare double @llvm.sin.f64(double %Val)
5529 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5530 declare fp128 @llvm.sin.f128(fp128 %Val)
5531 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5532</pre>
5533
5534<h5>Overview:</h5>
5535
5536<p>
5537The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
5538</p>
5539
5540<h5>Arguments:</h5>
5541
5542<p>
5543The argument and return value are floating point numbers of the same type.
5544</p>
5545
5546<h5>Semantics:</h5>
5547
5548<p>
5549This function returns the sine of the specified operand, returning the
5550same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5551conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5552</div>
5553
5554<!-- _______________________________________________________________________ -->
5555<div class="doc_subsubsection">
5556 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5557</div>
5558
5559<div class="doc_text">
5560
5561<h5>Syntax:</h5>
5562<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5563floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5564types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5565<pre>
5566 declare float @llvm.cos.f32(float %Val)
5567 declare double @llvm.cos.f64(double %Val)
5568 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5569 declare fp128 @llvm.cos.f128(fp128 %Val)
5570 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5571</pre>
5572
5573<h5>Overview:</h5>
5574
5575<p>
5576The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
5577</p>
5578
5579<h5>Arguments:</h5>
5580
5581<p>
5582The argument and return value are floating point numbers of the same type.
5583</p>
5584
5585<h5>Semantics:</h5>
5586
5587<p>
5588This function returns the cosine of the specified operand, returning the
5589same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5590conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5591</div>
5592
5593<!-- _______________________________________________________________________ -->
5594<div class="doc_subsubsection">
5595 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5596</div>
5597
5598<div class="doc_text">
5599
5600<h5>Syntax:</h5>
5601<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5602floating point or vector of floating point type. Not all targets support all
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5603types however.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5604<pre>
5605 declare float @llvm.pow.f32(float %Val, float %Power)
5606 declare double @llvm.pow.f64(double %Val, double %Power)
5607 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5608 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5609 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5610</pre>
5611
5612<h5>Overview:</h5>
5613
5614<p>
5615The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5616specified (positive or negative) power.
5617</p>
5618
5619<h5>Arguments:</h5>
5620
5621<p>
5622The second argument is a floating point power, and the first is a value to
5623raise to that power.
5624</p>
5625
5626<h5>Semantics:</h5>
5627
5628<p>
5629This function returns the first value raised to the second power,
5630returning the
5631same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]5632conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5633</div>
5634
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5635
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5636<!-- ======================================================================= -->
5637<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5638 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5639</div>
5640
5641<div class="doc_text">
5642<p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5643LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5644These allow efficient code generation for some algorithms.
5645</p>
5646
5647</div>
5648
5649<!-- _______________________________________________________________________ -->
5650<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5651 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5652</div>
5653
5654<div class="doc_text">
5655
5656<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5657<p>This is an overloaded intrinsic function. You can use bswap on any integer
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5658type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5659<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5660 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5661 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5662 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5663</pre>
5664
5665<h5>Overview:</h5>
5666
5667<p>
Reid Spencer338ea092007-04-02 02:25:19 +0000[diff] [blame]5668The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5669values with an even number of bytes (positive multiple of 16 bits). These are
5670useful for performing operations on data that is not in the target's native
5671byte order.
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5672</p>
5673
5674<h5>Semantics:</h5>
5675
5676<p>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5677The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5678and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
5679intrinsic returns an i32 value that has the four bytes of the input i32
5680swapped, 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]5681i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
5682<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5683additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5684</p>
5685
5686</div>
5687
5688<!-- _______________________________________________________________________ -->
5689<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5690 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5691</div>
5692
5693<div class="doc_text">
5694
5695<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5696<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]5697width. Not all targets support all bit widths however.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5698<pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame^]5699 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5700 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5701 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5702 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5703 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5704</pre>
5705
5706<h5>Overview:</h5>
5707
5708<p>
Chris Lattnerec6cb612006-01-16 22:38:59 +0000[diff] [blame]5709The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
5710value.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5711</p>
5712
5713<h5>Arguments:</h5>
5714
5715<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]5716The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5717integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5718</p>
5719
5720<h5>Semantics:</h5>
5721
5722<p>
5723The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
5724</p>
5725</div>
5726
5727<!-- _______________________________________________________________________ -->
5728<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5729 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5730</div>
5731
5732<div class="doc_text">
5733
5734<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5735<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]5736integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5737<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5738 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5739 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5740 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5741 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5742 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5743</pre>
5744
5745<h5>Overview:</h5>
5746
5747<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5748The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5749leading zeros in a variable.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5750</p>
5751
5752<h5>Arguments:</h5>
5753
5754<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]5755The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5756integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5757</p>
5758
5759<h5>Semantics:</h5>
5760
5761<p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5762The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
5763in 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]5764of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5765</p>
5766</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5767
5768
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5769
5770<!-- _______________________________________________________________________ -->
5771<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5772 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5773</div>
5774
5775<div class="doc_text">
5776
5777<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5778<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]5779integer bit width. Not all targets support all bit widths however.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5780<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5781 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5782 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5783 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5784 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5785 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5786</pre>
5787
5788<h5>Overview:</h5>
5789
5790<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5791The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5792trailing zeros.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5793</p>
5794
5795<h5>Arguments:</h5>
5796
5797<p>
5798The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]5799integer type. The return type must match the argument type.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5800</p>
5801
5802<h5>Semantics:</h5>
5803
5804<p>
5805The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
5806in a variable. If the src == 0 then the result is the size in bits of the type
5807of src. For example, <tt>llvm.cttz(2) = 1</tt>.
5808</p>
5809</div>
5810
Reid Spencer497d93e2007-04-01 08:27:01 +0000[diff] [blame]5811<!-- _______________________________________________________________________ -->
5812<div class="doc_subsubsection">
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5813 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5814</div>
5815
5816<div class="doc_text">
5817
5818<h5>Syntax:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5819<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5820on any integer bit width.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5821<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5822 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
5823 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5824</pre>
5825
5826<h5>Overview:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5827<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5828range of bits from an integer value and returns them in the same bit width as
5829the original value.</p>
5830
5831<h5>Arguments:</h5>
5832<p>The first argument, <tt>%val</tt> and the result may be integer types of
5833any bit width but they must have the same bit width. The second and third
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5834arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5835
5836<h5>Semantics:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]5837<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5838of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
5839<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
5840operates in forward mode.</p>
5841<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
5842right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5843only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
5844<ol>
5845 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
5846 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
5847 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
5848 to determine the number of bits to retain.</li>
5849 <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]5850 <li>The mask is ANDed with <tt>%val</tt> to produce the result.</li>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5851</ol>
Reid Spencerd6a85b52007-05-14 16:14:57 +0000[diff] [blame]5852<p>In reverse mode, a similar computation is made except that the bits are
5853returned in the reverse order. So, for example, if <tt>X</tt> has the value
5854<tt>i16 0x0ACF (101011001111)</tt> and we apply
5855<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
5856<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5857</div>
5858
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5859<div class="doc_subsubsection">
5860 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
5861</div>
5862
5863<div class="doc_text">
5864
5865<h5>Syntax:</h5>
5866<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5867on any integer bit width.</p>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5868<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5869 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
5870 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]5871</pre>
5872
5873<h5>Overview:</h5>
5874<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
5875of bits in an integer value with another integer value. It returns the integer
5876with the replaced bits.</p>
5877
5878<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame^]5879<p>The first argument, <tt>%val</tt>, and the result may be integer types of
5880any 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]5881whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
5882integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
5883type since they specify only a bit index.</p>
5884
5885<h5>Semantics:</h5>
5886<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
5887of operation: forwards and reverse. If <tt>%lo</tt> is greater than
5888<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
5889operates in forward mode.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame^]5890
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5891<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
5892truncating it down to the size of the replacement area or zero extending it
5893up to that size.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame^]5894
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5895<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5896are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5897in <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]5898to the <tt>%hi</tt>th bit.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame^]5899
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5900<p>In reverse mode, a similar computation is made except that the bits are
5901reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5902<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^]5903
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5904<h5>Examples:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame^]5905
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5906<pre>
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5907 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5908 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5909 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5910 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5911 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]5912</pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame^]5913
5914</div>
5915
5916<!-- _______________________________________________________________________ -->
5917<div class="doc_subsubsection">
5918 <a name="int_sadd_ovf">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
5919</div>
5920
5921<div class="doc_text">
5922
5923<h5>Syntax:</h5>
5924
5925<p>This is an overloaded intrinsic. You can use <tt>llvm.sadd.with.overflow</tt>
5926on any integer bit width. However, not all targets support all bit widths.</p>
5927
5928<pre>
5929 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
5930 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
5931 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
5932</pre>
5933
5934<h5>Overview:</h5>
5935
5936<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
5937a signed addition of the two arguments, and indicate whether an overflow
5938occurred during the signed summation.</p>
5939
5940<h5>Arguments:</h5>
5941
5942<p>The arguments (%a and %b) and the first element of the result structure may
5943be of integer types of any bit width, but they must have the same bit width. The
5944second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
5945and <tt>%b</tt> are the two values that will undergo signed addition.</p>
5946
5947<h5>Semantics:</h5>
5948
5949<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
5950a signed addition of the two variables. They return a structure &mdash; the
5951first element of which is the signed summation, and the second element of which
5952is a bit specifying if the signed summation resulted in an overflow.</p>
5953
5954<h5>Examples:</h5>
5955<pre>
5956 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
5957 %sum = extractvalue {i32, i1} %res, 0
5958 %obit = extractvalue {i32, i1} %res, 1
5959 br i1 %obit, label %overflow, label %normal
5960</pre>
5961
5962</div>
5963
5964<!-- _______________________________________________________________________ -->
5965<div class="doc_subsubsection">
5966 <a name="int_uadd_ovf">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
5967</div>
5968
5969<div class="doc_text">
5970
5971<h5>Syntax:</h5>
5972
5973<p>This is an overloaded intrinsic. You can use <tt>llvm.uadd.with.overflow</tt>
5974on any integer bit width. However, not all targets support all bit widths.</p>
5975
5976<pre>
5977 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
5978 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
5979 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
5980</pre>
5981
5982<h5>Overview:</h5>
5983
5984<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
5985an unsigned addition of the two arguments, and indicate whether a carry occurred
5986during the unsigned summation.</p>
5987
5988<h5>Arguments:</h5>
5989
5990<p>The arguments (%a and %b) and the first element of the result structure may
5991be of integer types of any bit width, but they must have the same bit width. The
5992second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
5993and <tt>%b</tt> are the two values that will undergo unsigned addition.</p>
5994
5995<h5>Semantics:</h5>
5996
5997<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
5998an unsigned addition of the two arguments. They return a structure &mdash; the
5999first element of which is the sum, and the second element of which is a bit
6000specifying if the unsigned summation resulted in a carry.</p>
6001
6002<h5>Examples:</h5>
6003<pre>
6004 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6005 %sum = extractvalue {i32, i1} %res, 0
6006 %obit = extractvalue {i32, i1} %res, 1
6007 br i1 %obit, label %carry, label %normal
6008</pre>
6009
6010</div>
6011
6012<!-- _______________________________________________________________________ -->
6013<div class="doc_subsubsection">
6014 <a name="int_ssub_ovf">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
6015</div>
6016
6017<div class="doc_text">
6018
6019<h5>Syntax:</h5>
6020
6021<p>This is an overloaded intrinsic. You can use <tt>llvm.ssub.with.overflow</tt>
6022on any integer bit width. However, not all targets support all bit widths.</p>
6023
6024<pre>
6025 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6026 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6027 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6028</pre>
6029
6030<h5>Overview:</h5>
6031
6032<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
6033a signed subtraction of the two arguments, and indicate whether an overflow
6034occurred during the signed subtraction.</p>
6035
6036<h5>Arguments:</h5>
6037
6038<p>The arguments (%a and %b) and the first element of the result structure may
6039be of integer types of any bit width, but they must have the same bit width. The
6040second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
6041and <tt>%b</tt> are the two values that will undergo signed subtraction.</p>
6042
6043<h5>Semantics:</h5>
6044
6045<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
6046a signed subtraction of the two arguments. They return a structure &mdash; the
6047first element of which is the subtraction, and the second element of which is a bit
6048specifying if the signed subtraction resulted in an overflow.</p>
6049
6050<h5>Examples:</h5>
6051<pre>
6052 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6053 %sum = extractvalue {i32, i1} %res, 0
6054 %obit = extractvalue {i32, i1} %res, 1
6055 br i1 %obit, label %overflow, label %normal
6056</pre>
6057
6058</div>
6059
6060<!-- _______________________________________________________________________ -->
6061<div class="doc_subsubsection">
6062 <a name="int_usub_ovf">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
6063</div>
6064
6065<div class="doc_text">
6066
6067<h5>Syntax:</h5>
6068
6069<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
6070on any integer bit width. However, not all targets support all bit widths.</p>
6071
6072<pre>
6073 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6074 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6075 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6076</pre>
6077
6078<h5>Overview:</h5>
6079
6080<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
6081an unsigned subtraction of the two arguments, and indicate whether an overflow
6082occurred during the unsigned subtraction.</p>
6083
6084<h5>Arguments:</h5>
6085
6086<p>The arguments (%a and %b) and the first element of the result structure may
6087be of integer types of any bit width, but they must have the same bit width. The
6088second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
6089and <tt>%b</tt> are the two values that will undergo unsigned subtraction.</p>
6090
6091<h5>Semantics:</h5>
6092
6093<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
6094an unsigned subtraction of the two arguments. They return a structure &mdash; the
6095first element of which is the subtraction, and the second element of which is a bit
6096specifying if the unsigned subtraction resulted in an overflow.</p>
6097
6098<h5>Examples:</h5>
6099<pre>
6100 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6101 %sum = extractvalue {i32, i1} %res, 0
6102 %obit = extractvalue {i32, i1} %res, 1
6103 br i1 %obit, label %overflow, label %normal
6104</pre>
6105
6106</div>
6107
6108<!-- _______________________________________________________________________ -->
6109<div class="doc_subsubsection">
6110 <a name="int_smul_ovf">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
6111</div>
6112
6113<div class="doc_text">
6114
6115<h5>Syntax:</h5>
6116
6117<p>This is an overloaded intrinsic. You can use <tt>llvm.smul.with.overflow</tt>
6118on any integer bit width. However, not all targets support all bit widths.</p>
6119
6120<pre>
6121 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6122 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6123 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6124</pre>
6125
6126<h5>Overview:</h5>
6127
6128<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
6129a signed multiplication of the two arguments, and indicate whether an overflow
6130occurred during the signed multiplication.</p>
6131
6132<h5>Arguments:</h5>
6133
6134<p>The arguments (%a and %b) and the first element of the result structure may
6135be of integer types of any bit width, but they must have the same bit width. The
6136second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
6137and <tt>%b</tt> are the two values that will undergo signed multiplication.</p>
6138
6139<h5>Semantics:</h5>
6140
6141<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
6142a signed multiplication of the two arguments. They return a structure &mdash;
6143the first element of which is the multiplication, and the second element of
6144which is a bit specifying if the signed multiplication resulted in an
6145overflow.</p>
6146
6147<h5>Examples:</h5>
6148<pre>
6149 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6150 %sum = extractvalue {i32, i1} %res, 0
6151 %obit = extractvalue {i32, i1} %res, 1
6152 br i1 %obit, label %overflow, label %normal
6153</pre>
6154
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]6155</div>
6156
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6157<!-- ======================================================================= -->
6158<div class="doc_subsection">
6159 <a name="int_debugger">Debugger Intrinsics</a>
6160</div>
6161
6162<div class="doc_text">
6163<p>
6164The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
6165are described in the <a
6166href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
6167Debugging</a> document.
6168</p>
6169</div>
6170
6171
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6172<!-- ======================================================================= -->
6173<div class="doc_subsection">
6174 <a name="int_eh">Exception Handling Intrinsics</a>
6175</div>
6176
6177<div class="doc_text">
6178<p> The LLVM exception handling intrinsics (which all start with
6179<tt>llvm.eh.</tt> prefix), are described in the <a
6180href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
6181Handling</a> document. </p>
6182</div>
6183
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6184<!-- ======================================================================= -->
6185<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6186 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6187</div>
6188
6189<div class="doc_text">
6190<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6191 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6192 the <tt>nest</tt> attribute, from a function. The result is a callable
6193 function pointer lacking the nest parameter - the caller does not need
6194 to provide a value for it. Instead, the value to use is stored in
6195 advance in a "trampoline", a block of memory usually allocated
6196 on the stack, which also contains code to splice the nest value into the
6197 argument list. This is used to implement the GCC nested function address
6198 extension.
6199</p>
6200<p>
6201 For example, if the function is
6202 <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]6203 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]6204<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6205 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
6206 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
6207 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
6208 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6209</pre>
Bill Wendling03295ca2007-09-22 09:23:55 +0000[diff] [blame]6210 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
6211 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6212</div>
6213
6214<!-- _______________________________________________________________________ -->
6215<div class="doc_subsubsection">
6216 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
6217</div>
6218<div class="doc_text">
6219<h5>Syntax:</h5>
6220<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6221declare 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]6222</pre>
6223<h5>Overview:</h5>
6224<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6225 This fills the memory pointed to by <tt>tramp</tt> with code
6226 and returns a function pointer suitable for executing it.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6227</p>
6228<h5>Arguments:</h5>
6229<p>
6230 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
6231 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
6232 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsc00c2ba2007-08-22 23:39:54 +0000[diff] [blame]6233 intrinsic. Note that the size and the alignment are target-specific - LLVM
6234 currently provides no portable way of determining them, so a front-end that
6235 generates this intrinsic needs to have some target-specific knowledge.
6236 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]6237</p>
6238<h5>Semantics:</h5>
6239<p>
6240 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6241 dependent code, turning it into a function. A pointer to this function is
6242 returned, but needs to be bitcast to an
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6243 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6244 before being called. The new function's signature is the same as that of
6245 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
6246 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
6247 of pointer type. Calling the new function is equivalent to calling
6248 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
6249 missing <tt>nest</tt> argument. If, after calling
6250 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
6251 modified, then the effect of any later call to the returned function pointer is
6252 undefined.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6253</p>
6254</div>
6255
6256<!-- ======================================================================= -->
6257<div class="doc_subsection">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6258 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
6259</div>
6260
6261<div class="doc_text">
6262<p>
6263 These intrinsic functions expand the "universal IR" of LLVM to represent
6264 hardware constructs for atomic operations and memory synchronization. This
6265 provides an interface to the hardware, not an interface to the programmer. It
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]6266 is aimed at a low enough level to allow any programming models or APIs
6267 (Application Programming Interfaces) which
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6268 need atomic behaviors to map cleanly onto it. It is also modeled primarily on
6269 hardware behavior. Just as hardware provides a "universal IR" for source
6270 languages, it also provides a starting point for developing a "universal"
6271 atomic operation and synchronization IR.
6272</p>
6273<p>
6274 These do <em>not</em> form an API such as high-level threading libraries,
6275 software transaction memory systems, atomic primitives, and intrinsic
6276 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
6277 application libraries. The hardware interface provided by LLVM should allow
6278 a clean implementation of all of these APIs and parallel programming models.
6279 No one model or paradigm should be selected above others unless the hardware
6280 itself ubiquitously does so.
6281
6282</p>
6283</div>
6284
6285<!-- _______________________________________________________________________ -->
6286<div class="doc_subsubsection">
6287 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
6288</div>
6289<div class="doc_text">
6290<h5>Syntax:</h5>
6291<pre>
6292declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;,
6293i1 &lt;device&gt; )
6294
6295</pre>
6296<h5>Overview:</h5>
6297<p>
6298 The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
6299 specific pairs of memory access types.
6300</p>
6301<h5>Arguments:</h5>
6302<p>
6303 The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
6304 The first four arguments enables a specific barrier as listed below. The fith
6305 argument specifies that the barrier applies to io or device or uncached memory.
6306
6307</p>
6308 <ul>
6309 <li><tt>ll</tt>: load-load barrier</li>
6310 <li><tt>ls</tt>: load-store barrier</li>
6311 <li><tt>sl</tt>: store-load barrier</li>
6312 <li><tt>ss</tt>: store-store barrier</li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6313 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6314 </ul>
6315<h5>Semantics:</h5>
6316<p>
6317 This intrinsic causes the system to enforce some ordering constraints upon
6318 the loads and stores of the program. This barrier does not indicate
6319 <em>when</em> any events will occur, it only enforces an <em>order</em> in
6320 which they occur. For any of the specified pairs of load and store operations
6321 (f.ex. load-load, or store-load), all of the first operations preceding the
6322 barrier will complete before any of the second operations succeeding the
6323 barrier begin. Specifically the semantics for each pairing is as follows:
6324</p>
6325 <ul>
6326 <li><tt>ll</tt>: All loads before the barrier must complete before any load
6327 after the barrier begins.</li>
6328
6329 <li><tt>ls</tt>: All loads before the barrier must complete before any
6330 store after the barrier begins.</li>
6331 <li><tt>ss</tt>: All stores before the barrier must complete before any
6332 store after the barrier begins.</li>
6333 <li><tt>sl</tt>: All stores before the barrier must complete before any
6334 load after the barrier begins.</li>
6335 </ul>
6336<p>
6337 These semantics are applied with a logical "and" behavior when more than one
6338 is enabled in a single memory barrier intrinsic.
6339</p>
6340<p>
6341 Backends may implement stronger barriers than those requested when they do not
6342 support as fine grained a barrier as requested. Some architectures do not
6343 need all types of barriers and on such architectures, these become noops.
6344</p>
6345<h5>Example:</h5>
6346<pre>
6347%ptr = malloc i32
6348 store i32 4, %ptr
6349
6350%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
6351 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
6352 <i>; guarantee the above finishes</i>
6353 store i32 8, %ptr <i>; before this begins</i>
6354</pre>
6355</div>
6356
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6357<!-- _______________________________________________________________________ -->
6358<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6359 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6360</div>
6361<div class="doc_text">
6362<h5>Syntax:</h5>
6363<p>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6364 This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
6365 any integer bit width and for different address spaces. Not all targets
6366 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6367
6368<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6369declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6370declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6371declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
6372declare 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]6373
6374</pre>
6375<h5>Overview:</h5>
6376<p>
6377 This loads a value in memory and compares it to a given value. If they are
6378 equal, it stores a new value into the memory.
6379</p>
6380<h5>Arguments:</h5>
6381<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6382 The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6383 well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
6384 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
6385 this integer type. While any bit width integer may be used, targets may only
6386 lower representations they support in hardware.
6387
6388</p>
6389<h5>Semantics:</h5>
6390<p>
6391 This entire intrinsic must be executed atomically. It first loads the value
6392 in memory pointed to by <tt>ptr</tt> and compares it with the value
6393 <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
6394 loaded value is yielded in all cases. This provides the equivalent of an
6395 atomic compare-and-swap operation within the SSA framework.
6396</p>
6397<h5>Examples:</h5>
6398
6399<pre>
6400%ptr = malloc i32
6401 store i32 4, %ptr
6402
6403%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6404%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6405 <i>; yields {i32}:result1 = 4</i>
6406%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6407%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6408
6409%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6410%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6411 <i>; yields {i32}:result2 = 8</i>
6412%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6413
6414%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6415</pre>
6416</div>
6417
6418<!-- _______________________________________________________________________ -->
6419<div class="doc_subsubsection">
6420 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6421</div>
6422<div class="doc_text">
6423<h5>Syntax:</h5>
6424
6425<p>
6426 This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6427 integer bit width. Not all targets support all bit widths however.</p>
6428<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6429declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6430declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6431declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6432declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6433
6434</pre>
6435<h5>Overview:</h5>
6436<p>
6437 This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6438 the value from memory. It then stores the value in <tt>val</tt> in the memory
6439 at <tt>ptr</tt>.
6440</p>
6441<h5>Arguments:</h5>
6442
6443<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6444 The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6445 <tt>val</tt> argument and the result must be integers of the same bit width.
6446 The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6447 integer type. The targets may only lower integer representations they
6448 support.
6449</p>
6450<h5>Semantics:</h5>
6451<p>
6452 This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6453 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6454 equivalent of an atomic swap operation within the SSA framework.
6455
6456</p>
6457<h5>Examples:</h5>
6458<pre>
6459%ptr = malloc i32
6460 store i32 4, %ptr
6461
6462%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6463%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6464 <i>; yields {i32}:result1 = 4</i>
6465%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6466%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6467
6468%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6469%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6470 <i>; yields {i32}:result2 = 8</i>
6471
6472%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6473%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6474</pre>
6475</div>
6476
6477<!-- _______________________________________________________________________ -->
6478<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6479 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6480
6481</div>
6482<div class="doc_text">
6483<h5>Syntax:</h5>
6484<p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6485 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]6486 integer bit width. Not all targets support all bit widths however.</p>
6487<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6488declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6489declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6490declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6491declare 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]6492
6493</pre>
6494<h5>Overview:</h5>
6495<p>
6496 This intrinsic adds <tt>delta</tt> to the value stored in memory at
6497 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6498</p>
6499<h5>Arguments:</h5>
6500<p>
6501
6502 The intrinsic takes two arguments, the first a pointer to an integer value
6503 and the second an integer value. The result is also an integer value. These
6504 integer types can have any bit width, but they must all have the same bit
6505 width. The targets may only lower integer representations they support.
6506</p>
6507<h5>Semantics:</h5>
6508<p>
6509 This intrinsic does a series of operations atomically. It first loads the
6510 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6511 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6512</p>
6513
6514<h5>Examples:</h5>
6515<pre>
6516%ptr = malloc i32
6517 store i32 4, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6518%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6519 <i>; yields {i32}:result1 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6520%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6521 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6522%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6523 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6524%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6525</pre>
6526</div>
6527
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6528<!-- _______________________________________________________________________ -->
6529<div class="doc_subsubsection">
6530 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6531
6532</div>
6533<div class="doc_text">
6534<h5>Syntax:</h5>
6535<p>
6536 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]6537 any integer bit width and for different address spaces. Not all targets
6538 support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6539<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6540declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6541declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6542declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6543declare 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]6544
6545</pre>
6546<h5>Overview:</h5>
6547<p>
6548 This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6549 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6550</p>
6551<h5>Arguments:</h5>
6552<p>
6553
6554 The intrinsic takes two arguments, the first a pointer to an integer value
6555 and the second an integer value. The result is also an integer value. These
6556 integer types can have any bit width, but they must all have the same bit
6557 width. The targets may only lower integer representations they support.
6558</p>
6559<h5>Semantics:</h5>
6560<p>
6561 This intrinsic does a series of operations atomically. It first loads the
6562 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6563 result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6564</p>
6565
6566<h5>Examples:</h5>
6567<pre>
6568%ptr = malloc i32
6569 store i32 8, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6570%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6571 <i>; yields {i32}:result1 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6572%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6573 <i>; yields {i32}:result2 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6574%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6575 <i>; yields {i32}:result3 = 2</i>
6576%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6577</pre>
6578</div>
6579
6580<!-- _______________________________________________________________________ -->
6581<div class="doc_subsubsection">
6582 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6583 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6584 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6585 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
6586
6587</div>
6588<div class="doc_text">
6589<h5>Syntax:</h5>
6590<p>
6591 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
6592 <tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6593 <tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
6594 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6595<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6596declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6597declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6598declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6599declare 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]6600
6601</pre>
6602
6603<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6604declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6605declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6606declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6607declare 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]6608
6609</pre>
6610
6611<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6612declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6613declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6614declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6615declare 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]6616
6617</pre>
6618
6619<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6620declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6621declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6622declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6623declare 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]6624
6625</pre>
6626<h5>Overview:</h5>
6627<p>
6628 These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6629 the value stored in memory at <tt>ptr</tt>. It yields the original value
6630 at <tt>ptr</tt>.
6631</p>
6632<h5>Arguments:</h5>
6633<p>
6634
6635 These intrinsics take two arguments, the first a pointer to an integer value
6636 and the second an integer value. The result is also an integer value. These
6637 integer types can have any bit width, but they must all have the same bit
6638 width. The targets may only lower integer representations they support.
6639</p>
6640<h5>Semantics:</h5>
6641<p>
6642 These intrinsics does a series of operations atomically. They first load the
6643 value stored at <tt>ptr</tt>. They then do the bitwise operation
6644 <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
6645 value stored at <tt>ptr</tt>.
6646</p>
6647
6648<h5>Examples:</h5>
6649<pre>
6650%ptr = malloc i32
6651 store i32 0x0F0F, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6652%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6653 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6654%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6655 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6656%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6657 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6658%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6659 <i>; yields {i32}:result3 = FF</i>
6660%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6661</pre>
6662</div>
6663
6664
6665<!-- _______________________________________________________________________ -->
6666<div class="doc_subsubsection">
6667 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6668 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6669 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6670 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
6671
6672</div>
6673<div class="doc_text">
6674<h5>Syntax:</h5>
6675<p>
6676 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6677 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6678 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6679 address spaces. Not all targets
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6680 support all bit widths however.</p>
6681<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6682declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6683declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6684declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6685declare 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]6686
6687</pre>
6688
6689<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6690declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6691declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6692declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6693declare 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]6694
6695</pre>
6696
6697<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6698declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6699declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6700declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6701declare 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]6702
6703</pre>
6704
6705<pre>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6706declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6707declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6708declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6709declare 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]6710
6711</pre>
6712<h5>Overview:</h5>
6713<p>
6714 These intrinsics takes the signed or unsigned minimum or maximum of
6715 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6716 original value at <tt>ptr</tt>.
6717</p>
6718<h5>Arguments:</h5>
6719<p>
6720
6721 These intrinsics take two arguments, the first a pointer to an integer value
6722 and the second an integer value. The result is also an integer value. These
6723 integer types can have any bit width, but they must all have the same bit
6724 width. The targets may only lower integer representations they support.
6725</p>
6726<h5>Semantics:</h5>
6727<p>
6728 These intrinsics does a series of operations atomically. They first load the
6729 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
6730 <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
6731 the original value stored at <tt>ptr</tt>.
6732</p>
6733
6734<h5>Examples:</h5>
6735<pre>
6736%ptr = malloc i32
6737 store i32 7, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6738%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6739 <i>; yields {i32}:result0 = 7</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6740%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6741 <i>; yields {i32}:result1 = -2</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6742%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6743 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6744%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6745 <i>; yields {i32}:result3 = 8</i>
6746%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6747</pre>
6748</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6749
6750<!-- ======================================================================= -->
6751<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6752 <a name="int_general">General Intrinsics</a>
6753</div>
6754
6755<div class="doc_text">
6756<p> This class of intrinsics is designed to be generic and has
6757no specific purpose. </p>
6758</div>
6759
6760<!-- _______________________________________________________________________ -->
6761<div class="doc_subsubsection">
6762 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6763</div>
6764
6765<div class="doc_text">
6766
6767<h5>Syntax:</h5>
6768<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]6769 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]6770</pre>
6771
6772<h5>Overview:</h5>
6773
6774<p>
6775The '<tt>llvm.var.annotation</tt>' intrinsic
6776</p>
6777
6778<h5>Arguments:</h5>
6779
6780<p>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]6781The first argument is a pointer to a value, the second is a pointer to a
6782global string, the third is a pointer to a global string which is the source
6783file name, and the last argument is the line number.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6784</p>
6785
6786<h5>Semantics:</h5>
6787
6788<p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6789This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6790This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6791annotations. These have no other defined use, they are ignored by code
6792generation and optimization.
6793</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6794</div>
6795
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6796<!-- _______________________________________________________________________ -->
6797<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]6798 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6799</div>
6800
6801<div class="doc_text">
6802
6803<h5>Syntax:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6804<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6805any integer bit width.
6806</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6807<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]6808 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6809 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6810 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6811 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6812 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]6813</pre>
6814
6815<h5>Overview:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6816
6817<p>
6818The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6819</p>
6820
6821<h5>Arguments:</h5>
6822
6823<p>
6824The first argument is an integer value (result of some expression),
6825the second is a pointer to a global string, the third is a pointer to a global
6826string which is the source file name, and the last argument is the line number.
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]6827It returns the value of the first argument.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6828</p>
6829
6830<h5>Semantics:</h5>
6831
6832<p>
6833This intrinsic allows annotations to be put on arbitrary expressions
6834with arbitrary strings. This can be useful for special purpose optimizations
6835that want to look for these annotations. These have no other defined use, they
6836are ignored by code generation and optimization.
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6837</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6838</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6839
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6840<!-- _______________________________________________________________________ -->
6841<div class="doc_subsubsection">
6842 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6843</div>
6844
6845<div class="doc_text">
6846
6847<h5>Syntax:</h5>
6848<pre>
6849 declare void @llvm.trap()
6850</pre>
6851
6852<h5>Overview:</h5>
6853
6854<p>
6855The '<tt>llvm.trap</tt>' intrinsic
6856</p>
6857
6858<h5>Arguments:</h5>
6859
6860<p>
6861None
6862</p>
6863
6864<h5>Semantics:</h5>
6865
6866<p>
6867This intrinsics is lowered to the target dependent trap instruction. If the
6868target does not have a trap instruction, this intrinsic will be lowered to the
6869call of the abort() function.
6870</p>
6871</div>
6872
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6873<!-- _______________________________________________________________________ -->
6874<div class="doc_subsubsection">
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]6875 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6876</div>
6877<div class="doc_text">
6878<h5>Syntax:</h5>
6879<pre>
6880declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
6881
6882</pre>
6883<h5>Overview:</h5>
6884<p>
6885 The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
6886 it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
6887 it is placed on the stack before local variables.
6888</p>
6889<h5>Arguments:</h5>
6890<p>
6891 The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
6892 first argument is the value loaded from the stack guard
6893 <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
6894 has enough space to hold the value of the guard.
6895</p>
6896<h5>Semantics:</h5>
6897<p>
6898 This intrinsic causes the prologue/epilogue inserter to force the position of
6899 the <tt>AllocaInst</tt> stack slot to be before local variables on the
6900 stack. This is to ensure that if a local variable on the stack is overwritten,
6901 it will destroy the value of the guard. When the function exits, the guard on
6902 the stack is checked against the original guard. If they're different, then
6903 the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
6904</p>
6905</div>
6906
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6907<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6908<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6909<address>
6910 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]6911 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6912 <a href="http://validator.w3.org/check/referer"><img
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Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6914
6915 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]6916 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6917 Last modified: $Date$
6918</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]6919
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6920</body>
6921</html>